Hi Jeff, Steve, Dominique,
I have been working on my netfslib helpers to the point that I can run
xfstests on AFS to completion (both with write-back buffering and, with a
small patch, write-through buffering in the pagecache). I have a patch for
9P, but am currently unable to test it.
The patches remove a little over 800 lines from AFS, 300 from 9P, albeit with
around 3000 lines added to netfs. Hopefully, I will be able to remove a bunch
of lines from Ceph too.
I've split the CIFS patches out to a separate branch, cifs-netfs, where a
further 2000+ lines are removed. I can run a certain amount of xfstests on
CIFS, though I'm running into ksmbd issues and not all the tests work
correctly because of issues between fallocate and what the SMB protocol
actually supports.
I've also dropped the content-crypto patches out for the moment as they're
only usable by the ceph changes which I'm still working on.
The patch to use PG_writeback instead of PG_fscache for writing to the
cache has also been deferred, pending 9p, afs, ceph and cifs all being
converted.
The main aims of these patches are to get high-level I/O and knowledge of
the pagecache out of the filesystem drivers as much as possible and to get
rid, as much of possible, of the knowledge that pages/folios exist.
Further, I would like to see ->write_begin, ->write_end and ->launder_folio
go away.
Features that are added by these patches to that which is already there in
netfslib:
(1) NFS-style (and Ceph-style) locking around DIO vs buffered I/O calls to
prevent these from happening at the same time. mmap'd I/O can, of
necessity, happen at any time ignoring these locks.
(2) Support for unbuffered I/O. The data is kept in the bounce buffer and
the pagecache is not used. This can be turned on with an inode flag.
(3) Support for direct I/O. This is basically unbuffered I/O with some
extra restrictions and no RMW.
(4) Support for using a bounce buffer in an operation. The bounce buffer
may be bigger than the target data/buffer, allowing for crypto
rounding.
(5) ->write_begin() and ->write_end() are ignored in favour of merging all
of that into one function, netfs_perform_write(), thereby avoiding the
function pointer traversals.
(6) Support for write-through caching in the pagecache.
netfs_perform_write() adds the pages is modifies to an I/O operation
as it goes and directly marks them writeback rather than dirty. When
writing back from write-through, it limits the range written back.
This should allow CIFS to deal with byte-range mandatory locks
correctly.
(7) O_*SYNC and RWF_*SYNC writes use write-through rather than writing to
the pagecache and then flushing afterwards. An AIO O_*SYNC write will
notify of completion when the sub-writes all complete.
(8) Support for write-streaming where modifed data is held in !uptodate
folios, with a private struct attached indicating the range that is
valid.
(9) Support for write grouping, multiplexing a pointer to a group in the
folio private data with the write-streaming data. The writepages
algorithm only writes stuff back that's in the nominated group. This
is intended for use by Ceph to write is snaps in order.
(10) Skipping reads for which we know the server could only supply zeros or
EOF (for instance if we've done a local write that leaves a hole in
the file and extends the local inode size).
General notes:
(1) The fscache module is merged into the netfslib module to avoid cyclic
exported symbol usage that prevents either module from being loaded.
(2) Some helpers from fscache are reassigned to netfslib by name.
(3) netfslib now makes use of folio->private, which means the filesystem
can't use it.
(4) The filesystem provides wrappers to call the write helpers, allowing
it to do pre-validation, oplock/capability fetching and the passing in
of write group info.
(5) I want to try flushing the data when tearing down an inode before
invalidating it to try and render launder_folio unnecessary.
(6) Write-through caching will generate and dispatch write subrequests as
it gathers enough data to hit wsize and has whole pages that at least
span that size. This needs to be a bit more flexible, allowing for a
filesystem such as CIFS to have a variable wsize.
(7) The filesystem driver is just given read and write calls with an
iov_iter describing the data/buffer to use. Ideally, they don't see
pages or folios at all. A function, extract_iter_to_sg(), is already
available to decant part of an iterator into a scatterlist for crypto
purposes.
AFS notes:
(1) I pushed a pair of patches that clean up the trace header down to the
base so that they can be shared with another branch.
9P notes:
(1) Most of xfstests now pass - more, in fact, since upstream 9p lacks a
writepages method and can't handle mmap writes. An occasional oops
(and sometimes panic) happens somewhere in the pathwalk/FID handling
code that is unrelated to these changes.
(2) Writes should now occur in larger-than-page-sized chunks.
(3) It should be possible to turn on multipage folio support in 9P now.
The patches are tagged as:
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/tag/?h=netfs-lib-20231221
and can also be found on the "netfs-lib" branch in the same repo.
Changes
=======
ver #5)
- Dropped bounce-buffer code for now as that's only used by content crypto
(which got deferred previously).
- Removed ceph_fscache_note_page_release() also as that is now unused.
- Cachefiles needs to depend on NETFS_SUPPORT also now.
- fscache_init/exit() should depend on CONFIG_FSCACHE, not CONFIG_PROC_FS.
- Adjust MAINTAINERS file.
- Sank afs trace header cleanup patches to base to share more easily with
another branch.
- 9p: Added some missing remote_i_size setting.
- 9p: Added missing writepages (else mmap write never written back).
- Use netfs_folio_info() rather than open-coding pointer mangling.
- Use folio_get_private() rather than using folio->private.
- Don't check the folio private pointer before taking the folio ref during
writeback pagecache RCU xarray walk.
- Change arch defconfigs to have NETFS_SUPPORT=m and FSCACHE=y when
FSCACHE was m.
ver #4)
- Slimmed down the branch:
- Split the cifs-related patches off to a separate branch (cifs-netfs)
- Deferred the content-encryption to the in-progress ceph changes.
- Deferred the use-PG_writeback rather than PG_fscache patch
- Rebased on a later linux-next with afs-rotation patches.
ver #3)
- Moved the fscache module into netfslib to avoid export cycles.
- Fixed a bunch of bugs.
- Got CIFS to pass as much of xfstests as possible.
- Added a patch to make 9P use all the helpers.
- Added a patch to stop using PG_fscache, but rather dirty pages on
reading and have writepages write to the cache.
ver #2)
- Folded the addition of NETFS_RREQ_NONBLOCK/BLOCKED into first patch that
uses them.
- Folded addition of rsize member into first user.
- Don't set rsize in ceph (yet) and set it in kafs to 256KiB. cifs sets
it dynamically.
- Moved direct_bv next to direct_bv_count in struct netfs_io_request and
labelled it with a __counted_by().
- Passed flags into netfs_xa_store_and_mark() rather than two bools.
- Removed netfs_set_up_buffer() as it wasn't used.
David
Link: https://lore.kernel.org/r/[email protected]/ # v1
Link: https://lore.kernel.org/r/[email protected]/ # v2
Link: https://lore.kernel.org/r/[email protected]/ # v3
Link: https://lore.kernel.org/r/[email protected]/ # v4
David Howells (40):
afs: Remove whitespace before most ')' from the trace header
afs: Automatically generate trace tag enums
netfs, fscache: Move fs/fscache/* into fs/netfs/
netfs, fscache: Combine fscache with netfs
netfs, fscache: Remove ->begin_cache_operation
netfs, fscache: Move /proc/fs/fscache to /proc/fs/netfs and put in a
symlink
netfs: Move pinning-for-writeback from fscache to netfs
netfs: Add a procfile to list in-progress requests
netfs: Allow the netfs to make the io (sub)request alloc larger
netfs: Add a ->free_subrequest() op
afs: Don't use folio->private to record partial modification
netfs: Provide invalidate_folio and release_folio calls
netfs: Implement unbuffered/DIO vs buffered I/O locking
netfs: Add iov_iters to (sub)requests to describe various buffers
netfs: Add support for DIO buffering
netfs: Provide tools to create a buffer in an xarray
netfs: Add func to calculate pagecount/size-limited span of an
iterator
netfs: Limit subrequest by size or number of segments
netfs: Extend the netfs_io_*request structs to handle writes
netfs: Add a hook to allow tell the netfs to update its i_size
netfs: Make netfs_put_request() handle a NULL pointer
netfs: Make the refcounting of netfs_begin_read() easier to use
netfs: Prep to use folio->private for write grouping and streaming
write
netfs: Dispatch write requests to process a writeback slice
netfs: Provide func to copy data to pagecache for buffered write
netfs: Make netfs_read_folio() handle streaming-write pages
netfs: Allocate multipage folios in the writepath
netfs: Implement unbuffered/DIO read support
netfs: Implement unbuffered/DIO write support
netfs: Implement buffered write API
netfs: Allow buffered shared-writeable mmap through
netfs_page_mkwrite()
netfs: Provide netfs_file_read_iter()
netfs, cachefiles: Pass upper bound length to allow expansion
netfs: Provide a writepages implementation
netfs: Provide a launder_folio implementation
netfs: Implement a write-through caching option
netfs: Optimise away reads above the point at which there can be no
data
netfs: Export the netfs_sreq tracepoint
afs: Use the netfs write helpers
9p: Use netfslib read/write_iter
Documentation/filesystems/netfs_library.rst | 23 +-
MAINTAINERS | 21 +-
arch/arm/configs/mxs_defconfig | 3 +-
arch/csky/configs/defconfig | 3 +-
arch/mips/configs/ip27_defconfig | 3 +-
arch/mips/configs/lemote2f_defconfig | 3 +-
arch/mips/configs/loongson3_defconfig | 3 +-
arch/mips/configs/pic32mzda_defconfig | 3 +-
arch/s390/configs/debug_defconfig | 3 +-
arch/s390/configs/defconfig | 3 +-
arch/sh/configs/sdk7786_defconfig | 3 +-
fs/9p/vfs_addr.c | 353 +----
fs/9p/vfs_file.c | 89 +-
fs/9p/vfs_inode.c | 8 +-
fs/9p/vfs_inode_dotl.c | 7 +-
fs/9p/vfs_super.c | 14 +-
fs/Kconfig | 1 -
fs/Makefile | 1 -
fs/afs/file.c | 213 +--
fs/afs/inode.c | 26 +-
fs/afs/internal.h | 72 +-
fs/afs/super.c | 2 +-
fs/afs/write.c | 828 +----------
fs/cachefiles/Kconfig | 2 +-
fs/cachefiles/internal.h | 2 +-
fs/cachefiles/io.c | 10 +-
fs/cachefiles/ondemand.c | 2 +-
fs/ceph/addr.c | 25 +-
fs/ceph/cache.h | 45 +-
fs/ceph/inode.c | 2 +-
fs/fs-writeback.c | 10 +-
fs/fscache/Kconfig | 40 -
fs/fscache/Makefile | 16 -
fs/fscache/internal.h | 277 ----
fs/netfs/Kconfig | 39 +
fs/netfs/Makefile | 22 +-
fs/netfs/buffered_read.c | 229 ++-
fs/netfs/buffered_write.c | 1236 +++++++++++++++++
fs/netfs/direct_read.c | 125 ++
fs/netfs/direct_write.c | 170 +++
fs/{fscache/cache.c => netfs/fscache_cache.c} | 0
.../cookie.c => netfs/fscache_cookie.c} | 0
fs/netfs/fscache_internal.h | 14 +
fs/{fscache/io.c => netfs/fscache_io.c} | 42 +-
fs/{fscache/main.c => netfs/fscache_main.c} | 25 +-
fs/{fscache/proc.c => netfs/fscache_proc.c} | 23 +-
fs/{fscache/stats.c => netfs/fscache_stats.c} | 4 +-
.../volume.c => netfs/fscache_volume.c} | 0
fs/netfs/internal.h | 288 ++++
fs/netfs/io.c | 211 ++-
fs/netfs/iterator.c | 97 ++
fs/netfs/locking.c | 216 +++
fs/netfs/main.c | 109 ++
fs/netfs/misc.c | 260 ++++
fs/netfs/objects.c | 59 +-
fs/netfs/output.c | 478 +++++++
fs/netfs/stats.c | 31 +-
fs/nfs/Kconfig | 4 +-
fs/nfs/fscache.c | 7 -
fs/smb/client/cifsfs.c | 9 +-
fs/smb/client/file.c | 18 +-
fs/smb/client/fscache.c | 2 +-
include/linux/fs.h | 2 +-
include/linux/fscache.h | 45 -
include/linux/netfs.h | 174 ++-
include/linux/writeback.h | 2 +-
include/trace/events/afs.h | 496 ++-----
include/trace/events/netfs.h | 155 ++-
mm/filemap.c | 2 +
69 files changed, 4233 insertions(+), 2477 deletions(-)
delete mode 100644 fs/fscache/Kconfig
delete mode 100644 fs/fscache/Makefile
delete mode 100644 fs/fscache/internal.h
create mode 100644 fs/netfs/buffered_write.c
create mode 100644 fs/netfs/direct_read.c
create mode 100644 fs/netfs/direct_write.c
rename fs/{fscache/cache.c => netfs/fscache_cache.c} (100%)
rename fs/{fscache/cookie.c => netfs/fscache_cookie.c} (100%)
create mode 100644 fs/netfs/fscache_internal.h
rename fs/{fscache/io.c => netfs/fscache_io.c} (86%)
rename fs/{fscache/main.c => netfs/fscache_main.c} (84%)
rename fs/{fscache/proc.c => netfs/fscache_proc.c} (58%)
rename fs/{fscache/stats.c => netfs/fscache_stats.c} (97%)
rename fs/{fscache/volume.c => netfs/fscache_volume.c} (100%)
create mode 100644 fs/netfs/locking.c
create mode 100644 fs/netfs/misc.c
create mode 100644 fs/netfs/output.c
Remove ->begin_cache_operation() in favour of just calling fscache directly.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Christian Brauner <[email protected]>
cc: [email protected]
cc: [email protected]
---
Documentation/filesystems/netfs_library.rst | 23 +++-----------
fs/9p/vfs_addr.c | 16 ----------
fs/afs/file.c | 13 --------
fs/ceph/addr.c | 1 -
fs/ceph/cache.h | 12 --------
fs/netfs/buffered_read.c | 33 +++++++++++----------
fs/nfs/fscache.c | 7 -----
include/linux/fscache.h | 3 --
include/linux/netfs.h | 4 +--
9 files changed, 23 insertions(+), 89 deletions(-)
diff --git a/Documentation/filesystems/netfs_library.rst b/Documentation/filesystems/netfs_library.rst
index 48b95d04f72d..4cc657d743f7 100644
--- a/Documentation/filesystems/netfs_library.rst
+++ b/Documentation/filesystems/netfs_library.rst
@@ -295,7 +295,6 @@ through which it can issue requests and negotiate::
struct netfs_request_ops {
void (*init_request)(struct netfs_io_request *rreq, struct file *file);
void (*free_request)(struct netfs_io_request *rreq);
- int (*begin_cache_operation)(struct netfs_io_request *rreq);
void (*expand_readahead)(struct netfs_io_request *rreq);
bool (*clamp_length)(struct netfs_io_subrequest *subreq);
void (*issue_read)(struct netfs_io_subrequest *subreq);
@@ -317,20 +316,6 @@ The operations are as follows:
[Optional] This is called as the request is being deallocated so that the
filesystem can clean up any state it has attached there.
- * ``begin_cache_operation()``
-
- [Optional] This is called to ask the network filesystem to call into the
- cache (if present) to initialise the caching state for this read. The netfs
- library module cannot access the cache directly, so the cache should call
- something like fscache_begin_read_operation() to do this.
-
- The cache gets to store its state in ->cache_resources and must set a table
- of operations of its own there (though of a different type).
-
- This should return 0 on success and an error code otherwise. If an error is
- reported, the operation may proceed anyway, just without local caching (only
- out of memory and interruption errors cause failure here).
-
* ``expand_readahead()``
[Optional] This is called to allow the filesystem to expand the size of a
@@ -460,14 +445,14 @@ When implementing a local cache to be used by the read helpers, two things are
required: some way for the network filesystem to initialise the caching for a
read request and a table of operations for the helpers to call.
-The network filesystem's ->begin_cache_operation() method is called to set up a
-cache and this must call into the cache to do the work. If using fscache, for
-example, the cache would call::
+To begin a cache operation on an fscache object, the following function is
+called::
int fscache_begin_read_operation(struct netfs_io_request *rreq,
struct fscache_cookie *cookie);
-passing in the request pointer and the cookie corresponding to the file.
+passing in the request pointer and the cookie corresponding to the file. This
+fills in the cache resources mentioned below.
The netfs_io_request object contains a place for the cache to hang its
state::
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 8a635999a7d6..39db7c01e30a 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -82,25 +82,9 @@ static void v9fs_free_request(struct netfs_io_request *rreq)
p9_fid_put(fid);
}
-/**
- * v9fs_begin_cache_operation - Begin a cache operation for a read
- * @rreq: The read request
- */
-static int v9fs_begin_cache_operation(struct netfs_io_request *rreq)
-{
-#ifdef CONFIG_9P_FSCACHE
- struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(rreq->inode));
-
- return fscache_begin_read_operation(&rreq->cache_resources, cookie);
-#else
- return -ENOBUFS;
-#endif
-}
-
const struct netfs_request_ops v9fs_req_ops = {
.init_request = v9fs_init_request,
.free_request = v9fs_free_request,
- .begin_cache_operation = v9fs_begin_cache_operation,
.issue_read = v9fs_issue_read,
};
diff --git a/fs/afs/file.c b/fs/afs/file.c
index d37dd201752b..8c17e37c2e59 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -366,18 +366,6 @@ static int afs_init_request(struct netfs_io_request *rreq, struct file *file)
return 0;
}
-static int afs_begin_cache_operation(struct netfs_io_request *rreq)
-{
-#ifdef CONFIG_AFS_FSCACHE
- struct afs_vnode *vnode = AFS_FS_I(rreq->inode);
-
- return fscache_begin_read_operation(&rreq->cache_resources,
- afs_vnode_cache(vnode));
-#else
- return -ENOBUFS;
-#endif
-}
-
static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len,
struct folio **foliop, void **_fsdata)
{
@@ -394,7 +382,6 @@ static void afs_free_request(struct netfs_io_request *rreq)
const struct netfs_request_ops afs_req_ops = {
.init_request = afs_init_request,
.free_request = afs_free_request,
- .begin_cache_operation = afs_begin_cache_operation,
.check_write_begin = afs_check_write_begin,
.issue_read = afs_issue_read,
};
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 85be3bf18cdf..3b8641febeac 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -509,7 +509,6 @@ static void ceph_netfs_free_request(struct netfs_io_request *rreq)
const struct netfs_request_ops ceph_netfs_ops = {
.init_request = ceph_init_request,
.free_request = ceph_netfs_free_request,
- .begin_cache_operation = ceph_begin_cache_operation,
.issue_read = ceph_netfs_issue_read,
.expand_readahead = ceph_netfs_expand_readahead,
.clamp_length = ceph_netfs_clamp_length,
diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
index dc502daac49a..b804f1094764 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -57,13 +57,6 @@ static inline int ceph_fscache_dirty_folio(struct address_space *mapping,
return fscache_dirty_folio(mapping, folio, ceph_fscache_cookie(ci));
}
-static inline int ceph_begin_cache_operation(struct netfs_io_request *rreq)
-{
- struct fscache_cookie *cookie = ceph_fscache_cookie(ceph_inode(rreq->inode));
-
- return fscache_begin_read_operation(&rreq->cache_resources, cookie);
-}
-
static inline bool ceph_is_cache_enabled(struct inode *inode)
{
return fscache_cookie_enabled(ceph_fscache_cookie(ceph_inode(inode)));
@@ -135,11 +128,6 @@ static inline bool ceph_is_cache_enabled(struct inode *inode)
return false;
}
-static inline int ceph_begin_cache_operation(struct netfs_io_request *rreq)
-{
- return -ENOBUFS;
-}
-
static inline void ceph_fscache_note_page_release(struct inode *inode)
{
}
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 2cd3ccf4c439..d39d0ffe75d2 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -147,6 +147,15 @@ static void netfs_rreq_expand(struct netfs_io_request *rreq,
}
}
+/*
+ * Begin an operation, and fetch the stored zero point value from the cookie if
+ * available.
+ */
+static int netfs_begin_cache_read(struct netfs_io_request *rreq, struct netfs_inode *ctx)
+{
+ return fscache_begin_read_operation(&rreq->cache_resources, netfs_i_cookie(ctx));
+}
+
/**
* netfs_readahead - Helper to manage a read request
* @ractl: The description of the readahead request
@@ -180,11 +189,9 @@ void netfs_readahead(struct readahead_control *ractl)
if (IS_ERR(rreq))
return;
- if (ctx->ops->begin_cache_operation) {
- ret = ctx->ops->begin_cache_operation(rreq);
- if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
- goto cleanup_free;
- }
+ ret = netfs_begin_cache_read(rreq, ctx);
+ if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
+ goto cleanup_free;
netfs_stat(&netfs_n_rh_readahead);
trace_netfs_read(rreq, readahead_pos(ractl), readahead_length(ractl),
@@ -238,11 +245,9 @@ int netfs_read_folio(struct file *file, struct folio *folio)
goto alloc_error;
}
- if (ctx->ops->begin_cache_operation) {
- ret = ctx->ops->begin_cache_operation(rreq);
- if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
- goto discard;
- }
+ ret = netfs_begin_cache_read(rreq, ctx);
+ if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
+ goto discard;
netfs_stat(&netfs_n_rh_readpage);
trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);
@@ -390,11 +395,9 @@ int netfs_write_begin(struct netfs_inode *ctx,
rreq->no_unlock_folio = folio_index(folio);
__set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);
- if (ctx->ops->begin_cache_operation) {
- ret = ctx->ops->begin_cache_operation(rreq);
- if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
- goto error_put;
- }
+ ret = netfs_begin_cache_read(rreq, ctx);
+ if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
+ goto error_put;
netfs_stat(&netfs_n_rh_write_begin);
trace_netfs_read(rreq, pos, len, netfs_read_trace_write_begin);
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index b05717fe0d4e..2d1bfee225c3 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -274,12 +274,6 @@ static void nfs_netfs_free_request(struct netfs_io_request *rreq)
put_nfs_open_context(rreq->netfs_priv);
}
-static inline int nfs_netfs_begin_cache_operation(struct netfs_io_request *rreq)
-{
- return fscache_begin_read_operation(&rreq->cache_resources,
- netfs_i_cookie(netfs_inode(rreq->inode)));
-}
-
static struct nfs_netfs_io_data *nfs_netfs_alloc(struct netfs_io_subrequest *sreq)
{
struct nfs_netfs_io_data *netfs;
@@ -387,7 +381,6 @@ void nfs_netfs_read_completion(struct nfs_pgio_header *hdr)
const struct netfs_request_ops nfs_netfs_ops = {
.init_request = nfs_netfs_init_request,
.free_request = nfs_netfs_free_request,
- .begin_cache_operation = nfs_netfs_begin_cache_operation,
.issue_read = nfs_netfs_issue_read,
.clamp_length = nfs_netfs_clamp_length
};
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index 8e312c8323a8..9ed6696aee7a 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -437,9 +437,6 @@ const struct netfs_cache_ops *fscache_operation_valid(const struct netfs_cache_r
* indicates the cache resources to which the operation state should be
* attached; @cookie indicates the cache object that will be accessed.
*
- * This is intended to be called from the ->begin_cache_operation() netfs lib
- * operation as implemented by the network filesystem.
- *
* @cres->inval_counter is set from @cookie->inval_counter for comparison at
* the end of the operation. This allows invalidation during the operation to
* be detected by the caller.
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index b11a84f6c32b..d294ff8f9ae4 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -208,7 +208,6 @@ struct netfs_io_request {
struct netfs_request_ops {
int (*init_request)(struct netfs_io_request *rreq, struct file *file);
void (*free_request)(struct netfs_io_request *rreq);
- int (*begin_cache_operation)(struct netfs_io_request *rreq);
void (*expand_readahead)(struct netfs_io_request *rreq);
bool (*clamp_length)(struct netfs_io_subrequest *subreq);
@@ -229,8 +228,7 @@ enum netfs_read_from_hole {
};
/*
- * Table of operations for access to a cache. This is obtained by
- * rreq->ops->begin_cache_operation().
+ * Table of operations for access to a cache.
*/
struct netfs_cache_ops {
/* End an operation */
Now that the fscache code is moved to be colocated with the netfslib code
so that they combined into one module, do the combining.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Christian Brauner <[email protected]>
cc: [email protected]
cc: [email protected]
---
Notes:
Changes
=======
ver #5)
- Cachefiles needs to depend on NETFS_SUPPORT also now.
- Change arch defconfigs to have NETFS_SUPPORT=m and FSCACHE=y when
FSCACHE was m.
arch/arm/configs/mxs_defconfig | 3 +-
arch/csky/configs/defconfig | 3 +-
arch/mips/configs/ip27_defconfig | 3 +-
arch/mips/configs/lemote2f_defconfig | 3 +-
arch/mips/configs/loongson3_defconfig | 3 +-
arch/mips/configs/pic32mzda_defconfig | 3 +-
arch/s390/configs/debug_defconfig | 3 +-
arch/s390/configs/defconfig | 3 +-
arch/sh/configs/sdk7786_defconfig | 3 +-
fs/cachefiles/Kconfig | 2 +-
fs/netfs/Kconfig | 4 +-
fs/netfs/Makefile | 24 +--
fs/netfs/fscache_internal.h | 267 +-------------------------
fs/netfs/fscache_main.c | 17 +-
fs/netfs/internal.h | 192 +++++++++++++++++-
fs/netfs/main.c | 4 +-
fs/nfs/Kconfig | 4 +-
17 files changed, 232 insertions(+), 309 deletions(-)
diff --git a/arch/arm/configs/mxs_defconfig b/arch/arm/configs/mxs_defconfig
index feb38a94c1a7..43bc1255a5db 100644
--- a/arch/arm/configs/mxs_defconfig
+++ b/arch/arm/configs/mxs_defconfig
@@ -138,7 +138,8 @@ CONFIG_PWM_MXS=y
CONFIG_NVMEM_MXS_OCOTP=y
CONFIG_EXT4_FS=y
# CONFIG_DNOTIFY is not set
-CONFIG_FSCACHE=m
+CONFIG_NETFS_SUPPORT=m
+CONFIG_FSCACHE=y
CONFIG_FSCACHE_STATS=y
CONFIG_CACHEFILES=m
CONFIG_VFAT_FS=y
diff --git a/arch/csky/configs/defconfig b/arch/csky/configs/defconfig
index af722e4dfb47..ff559e5162aa 100644
--- a/arch/csky/configs/defconfig
+++ b/arch/csky/configs/defconfig
@@ -34,7 +34,8 @@ CONFIG_GENERIC_PHY=y
CONFIG_EXT4_FS=y
CONFIG_FANOTIFY=y
CONFIG_QUOTA=y
-CONFIG_FSCACHE=m
+CONFIG_NETFS_SUPPORT=m
+CONFIG_FSCACHE=y
CONFIG_FSCACHE_STATS=y
CONFIG_CACHEFILES=m
CONFIG_MSDOS_FS=y
diff --git a/arch/mips/configs/ip27_defconfig b/arch/mips/configs/ip27_defconfig
index b51f738a39a0..4714074c8bd7 100644
--- a/arch/mips/configs/ip27_defconfig
+++ b/arch/mips/configs/ip27_defconfig
@@ -287,7 +287,8 @@ CONFIG_BTRFS_FS_POSIX_ACL=y
CONFIG_QUOTA_NETLINK_INTERFACE=y
CONFIG_FUSE_FS=m
CONFIG_CUSE=m
-CONFIG_FSCACHE=m
+CONFIG_NETFS_SUPPORT=m
+CONFIG_FSCACHE=y
CONFIG_FSCACHE_STATS=y
CONFIG_CACHEFILES=m
CONFIG_PROC_KCORE=y
diff --git a/arch/mips/configs/lemote2f_defconfig b/arch/mips/configs/lemote2f_defconfig
index 38f17b658421..3389e6e885d9 100644
--- a/arch/mips/configs/lemote2f_defconfig
+++ b/arch/mips/configs/lemote2f_defconfig
@@ -238,7 +238,8 @@ CONFIG_BTRFS_FS=m
CONFIG_QUOTA=y
CONFIG_QFMT_V2=m
CONFIG_AUTOFS_FS=m
-CONFIG_FSCACHE=m
+CONFIG_NETFS_SUPPORT=m
+CONFIG_FSCACHE=y
CONFIG_CACHEFILES=m
CONFIG_ISO9660_FS=m
CONFIG_JOLIET=y
diff --git a/arch/mips/configs/loongson3_defconfig b/arch/mips/configs/loongson3_defconfig
index 07839a4b397e..78f498752066 100644
--- a/arch/mips/configs/loongson3_defconfig
+++ b/arch/mips/configs/loongson3_defconfig
@@ -356,7 +356,8 @@ CONFIG_QFMT_V2=m
CONFIG_AUTOFS_FS=y
CONFIG_FUSE_FS=m
CONFIG_VIRTIO_FS=m
-CONFIG_FSCACHE=m
+CONFIG_NETFS_SUPPORT=m
+CONFIG_FSCACHE=y
CONFIG_ISO9660_FS=m
CONFIG_JOLIET=y
CONFIG_MSDOS_FS=m
diff --git a/arch/mips/configs/pic32mzda_defconfig b/arch/mips/configs/pic32mzda_defconfig
index 166d2ad372d1..54774f90c23e 100644
--- a/arch/mips/configs/pic32mzda_defconfig
+++ b/arch/mips/configs/pic32mzda_defconfig
@@ -68,7 +68,8 @@ CONFIG_EXT4_FS_POSIX_ACL=y
CONFIG_EXT4_FS_SECURITY=y
CONFIG_AUTOFS_FS=m
CONFIG_FUSE_FS=m
-CONFIG_FSCACHE=m
+CONFIG_NETFS_SUPPORT=m
+CONFIG_FSCACHE=y
CONFIG_ISO9660_FS=m
CONFIG_JOLIET=y
CONFIG_ZISOFS=y
diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig
index dd0608629310..005cdd3152b9 100644
--- a/arch/s390/configs/debug_defconfig
+++ b/arch/s390/configs/debug_defconfig
@@ -635,8 +635,9 @@ CONFIG_FUSE_FS=y
CONFIG_CUSE=m
CONFIG_VIRTIO_FS=m
CONFIG_OVERLAY_FS=m
+CONFIG_NETFS_SUPPORT=m
CONFIG_NETFS_STATS=y
-CONFIG_FSCACHE=m
+CONFIG_FSCACHE=y
CONFIG_CACHEFILES=m
CONFIG_ISO9660_FS=y
CONFIG_JOLIET=y
diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig
index 1b8150e50f6a..9d1d1ed62080 100644
--- a/arch/s390/configs/defconfig
+++ b/arch/s390/configs/defconfig
@@ -620,8 +620,9 @@ CONFIG_FUSE_FS=y
CONFIG_CUSE=m
CONFIG_VIRTIO_FS=m
CONFIG_OVERLAY_FS=m
+CONFIG_NETFS_SUPPORT=m
CONFIG_NETFS_STATS=y
-CONFIG_FSCACHE=m
+CONFIG_FSCACHE=y
CONFIG_CACHEFILES=m
CONFIG_ISO9660_FS=y
CONFIG_JOLIET=y
diff --git a/arch/sh/configs/sdk7786_defconfig b/arch/sh/configs/sdk7786_defconfig
index cf59b98446e4..7b427c17fbfe 100644
--- a/arch/sh/configs/sdk7786_defconfig
+++ b/arch/sh/configs/sdk7786_defconfig
@@ -171,7 +171,8 @@ CONFIG_BTRFS_FS=y
CONFIG_AUTOFS_FS=m
CONFIG_FUSE_FS=y
CONFIG_CUSE=m
-CONFIG_FSCACHE=m
+CONFIG_NETFS_SUPPORT=m
+CONFIG_FSCACHE=y
CONFIG_CACHEFILES=m
CONFIG_ISO9660_FS=m
CONFIG_JOLIET=y
diff --git a/fs/cachefiles/Kconfig b/fs/cachefiles/Kconfig
index 8df715640a48..c5a070550ee3 100644
--- a/fs/cachefiles/Kconfig
+++ b/fs/cachefiles/Kconfig
@@ -2,7 +2,7 @@
config CACHEFILES
tristate "Filesystem caching on files"
- depends on FSCACHE && BLOCK
+ depends on NETFS_SUPPORT && FSCACHE && BLOCK
help
This permits use of a mounted filesystem as a cache for other
filesystems - primarily networking filesystems - thus allowing fast
diff --git a/fs/netfs/Kconfig b/fs/netfs/Kconfig
index b4378688357c..bec805e0c44c 100644
--- a/fs/netfs/Kconfig
+++ b/fs/netfs/Kconfig
@@ -23,8 +23,8 @@ config NETFS_STATS
debugging purposes. Saying 'Y' here is recommended.
config FSCACHE
- tristate "General filesystem local caching manager"
- select NETFS_SUPPORT
+ bool "General filesystem local caching manager"
+ depends on NETFS_SUPPORT
help
This option enables a generic filesystem caching manager that can be
used by various network and other filesystems to cache data locally.
diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
index bbb2b824bd5e..b57162ef9cfb 100644
--- a/fs/netfs/Makefile
+++ b/fs/netfs/Makefile
@@ -1,17 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
-fscache-y := \
- fscache_cache.o \
- fscache_cookie.o \
- fscache_io.o \
- fscache_main.o \
- fscache_volume.o
-
-fscache-$(CONFIG_PROC_FS) += fscache_proc.o
-fscache-$(CONFIG_FSCACHE_STATS) += fscache_stats.o
-
-obj-$(CONFIG_FSCACHE) := fscache.o
-
netfs-y := \
buffered_read.o \
io.o \
@@ -21,4 +9,16 @@ netfs-y := \
netfs-$(CONFIG_NETFS_STATS) += stats.o
+netfs-$(CONFIG_FSCACHE) += \
+ fscache_cache.o \
+ fscache_cookie.o \
+ fscache_io.o \
+ fscache_main.o \
+ fscache_volume.o
+
+ifeq ($(CONFIG_PROC_FS),y)
+netfs-$(CONFIG_FSCACHE) += fscache_proc.o
+endif
+netfs-$(CONFIG_FSCACHE_STATS) += fscache_stats.o
+
obj-$(CONFIG_NETFS_SUPPORT) += netfs.o
diff --git a/fs/netfs/fscache_internal.h b/fs/netfs/fscache_internal.h
index 1336f517e9b1..a09b948fcef2 100644
--- a/fs/netfs/fscache_internal.h
+++ b/fs/netfs/fscache_internal.h
@@ -5,273 +5,10 @@
* Written by David Howells ([email protected])
*/
+#include "internal.h"
+
#ifdef pr_fmt
#undef pr_fmt
#endif
#define pr_fmt(fmt) "FS-Cache: " fmt
-
-#include <linux/slab.h>
-#include <linux/fscache-cache.h>
-#include <trace/events/fscache.h>
-#include <linux/sched.h>
-#include <linux/seq_file.h>
-
-/*
- * cache.c
- */
-#ifdef CONFIG_PROC_FS
-extern const struct seq_operations fscache_caches_seq_ops;
-#endif
-bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
-void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
-struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache);
-void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where);
-
-static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache)
-{
- return smp_load_acquire(&cache->state);
-}
-
-static inline bool fscache_cache_is_live(const struct fscache_cache *cache)
-{
- return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE;
-}
-
-static inline void fscache_set_cache_state(struct fscache_cache *cache,
- enum fscache_cache_state new_state)
-{
- smp_store_release(&cache->state, new_state);
-
-}
-
-static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache,
- enum fscache_cache_state old_state,
- enum fscache_cache_state new_state)
-{
- return try_cmpxchg_release(&cache->state, &old_state, new_state);
-}
-
-/*
- * cookie.c
- */
-extern struct kmem_cache *fscache_cookie_jar;
-#ifdef CONFIG_PROC_FS
-extern const struct seq_operations fscache_cookies_seq_ops;
-#endif
-extern struct timer_list fscache_cookie_lru_timer;
-
-extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix);
-extern bool fscache_begin_cookie_access(struct fscache_cookie *cookie,
- enum fscache_access_trace why);
-
-static inline void fscache_see_cookie(struct fscache_cookie *cookie,
- enum fscache_cookie_trace where)
-{
- trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
- where);
-}
-
-/*
- * main.c
- */
-extern unsigned fscache_debug;
-
-extern unsigned int fscache_hash(unsigned int salt, const void *data, size_t len);
-
-/*
- * proc.c
- */
-#ifdef CONFIG_PROC_FS
-extern int __init fscache_proc_init(void);
-extern void fscache_proc_cleanup(void);
-#else
-#define fscache_proc_init() (0)
-#define fscache_proc_cleanup() do {} while (0)
-#endif
-
-/*
- * stats.c
- */
-#ifdef CONFIG_FSCACHE_STATS
-extern atomic_t fscache_n_volumes;
-extern atomic_t fscache_n_volumes_collision;
-extern atomic_t fscache_n_volumes_nomem;
-extern atomic_t fscache_n_cookies;
-extern atomic_t fscache_n_cookies_lru;
-extern atomic_t fscache_n_cookies_lru_expired;
-extern atomic_t fscache_n_cookies_lru_removed;
-extern atomic_t fscache_n_cookies_lru_dropped;
-
-extern atomic_t fscache_n_acquires;
-extern atomic_t fscache_n_acquires_ok;
-extern atomic_t fscache_n_acquires_oom;
-
-extern atomic_t fscache_n_invalidates;
-
-extern atomic_t fscache_n_relinquishes;
-extern atomic_t fscache_n_relinquishes_retire;
-extern atomic_t fscache_n_relinquishes_dropped;
-
-extern atomic_t fscache_n_resizes;
-extern atomic_t fscache_n_resizes_null;
-
-static inline void fscache_stat(atomic_t *stat)
-{
- atomic_inc(stat);
-}
-
-static inline void fscache_stat_d(atomic_t *stat)
-{
- atomic_dec(stat);
-}
-
-#define __fscache_stat(stat) (stat)
-
-int fscache_stats_show(struct seq_file *m, void *v);
-#else
-
-#define __fscache_stat(stat) (NULL)
-#define fscache_stat(stat) do {} while (0)
-#define fscache_stat_d(stat) do {} while (0)
-#endif
-
-/*
- * volume.c
- */
-#ifdef CONFIG_PROC_FS
-extern const struct seq_operations fscache_volumes_seq_ops;
-#endif
-
-struct fscache_volume *fscache_get_volume(struct fscache_volume *volume,
- enum fscache_volume_trace where);
-void fscache_put_volume(struct fscache_volume *volume,
- enum fscache_volume_trace where);
-bool fscache_begin_volume_access(struct fscache_volume *volume,
- struct fscache_cookie *cookie,
- enum fscache_access_trace why);
-void fscache_create_volume(struct fscache_volume *volume, bool wait);
-
-
-/*****************************************************************************/
-/*
- * debug tracing
- */
-#define dbgprintk(FMT, ...) \
- printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
-
-#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
-#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
-#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
-
-#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
-
-#ifdef __KDEBUG
-#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
-#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
-#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
-
-#elif defined(CONFIG_FSCACHE_DEBUG)
-#define _enter(FMT, ...) \
-do { \
- if (__do_kdebug(ENTER)) \
- kenter(FMT, ##__VA_ARGS__); \
-} while (0)
-
-#define _leave(FMT, ...) \
-do { \
- if (__do_kdebug(LEAVE)) \
- kleave(FMT, ##__VA_ARGS__); \
-} while (0)
-
-#define _debug(FMT, ...) \
-do { \
- if (__do_kdebug(DEBUG)) \
- kdebug(FMT, ##__VA_ARGS__); \
-} while (0)
-
-#else
-#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
-#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
-#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
-#endif
-
-/*
- * determine whether a particular optional debugging point should be logged
- * - we need to go through three steps to persuade cpp to correctly join the
- * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
- */
-#define ____do_kdebug(LEVEL, POINT) \
- unlikely((fscache_debug & \
- (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
-#define ___do_kdebug(LEVEL, POINT) \
- ____do_kdebug(LEVEL, POINT)
-#define __do_kdebug(POINT) \
- ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
-
-#define FSCACHE_DEBUG_CACHE 0
-#define FSCACHE_DEBUG_COOKIE 1
-#define FSCACHE_DEBUG_OBJECT 2
-#define FSCACHE_DEBUG_OPERATION 3
-
-#define FSCACHE_POINT_ENTER 1
-#define FSCACHE_POINT_LEAVE 2
-#define FSCACHE_POINT_DEBUG 4
-
-#ifndef FSCACHE_DEBUG_LEVEL
-#define FSCACHE_DEBUG_LEVEL CACHE
-#endif
-
-/*
- * assertions
- */
-#if 1 /* defined(__KDEBUGALL) */
-
-#define ASSERT(X) \
-do { \
- if (unlikely(!(X))) { \
- pr_err("\n"); \
- pr_err("Assertion failed\n"); \
- BUG(); \
- } \
-} while (0)
-
-#define ASSERTCMP(X, OP, Y) \
-do { \
- if (unlikely(!((X) OP (Y)))) { \
- pr_err("\n"); \
- pr_err("Assertion failed\n"); \
- pr_err("%lx " #OP " %lx is false\n", \
- (unsigned long)(X), (unsigned long)(Y)); \
- BUG(); \
- } \
-} while (0)
-
-#define ASSERTIF(C, X) \
-do { \
- if (unlikely((C) && !(X))) { \
- pr_err("\n"); \
- pr_err("Assertion failed\n"); \
- BUG(); \
- } \
-} while (0)
-
-#define ASSERTIFCMP(C, X, OP, Y) \
-do { \
- if (unlikely((C) && !((X) OP (Y)))) { \
- pr_err("\n"); \
- pr_err("Assertion failed\n"); \
- pr_err("%lx " #OP " %lx is false\n", \
- (unsigned long)(X), (unsigned long)(Y)); \
- BUG(); \
- } \
-} while (0)
-
-#else
-
-#define ASSERT(X) do {} while (0)
-#define ASSERTCMP(X, OP, Y) do {} while (0)
-#define ASSERTIF(C, X) do {} while (0)
-#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
-
-#endif /* assert or not */
diff --git a/fs/netfs/fscache_main.c b/fs/netfs/fscache_main.c
index dad85fd84f6f..00600a4d9ce5 100644
--- a/fs/netfs/fscache_main.c
+++ b/fs/netfs/fscache_main.c
@@ -8,18 +8,9 @@
#define FSCACHE_DEBUG_LEVEL CACHE
#include <linux/module.h>
#include <linux/init.h>
-#define CREATE_TRACE_POINTS
#include "internal.h"
-
-MODULE_DESCRIPTION("FS Cache Manager");
-MODULE_AUTHOR("Red Hat, Inc.");
-MODULE_LICENSE("GPL");
-
-unsigned fscache_debug;
-module_param_named(debug, fscache_debug, uint,
- S_IWUSR | S_IRUGO);
-MODULE_PARM_DESC(fscache_debug,
- "FS-Cache debugging mask");
+#define CREATE_TRACE_POINTS
+#include <trace/events/fscache.h>
EXPORT_TRACEPOINT_SYMBOL(fscache_access_cache);
EXPORT_TRACEPOINT_SYMBOL(fscache_access_volume);
@@ -92,7 +83,7 @@ static int __init fscache_init(void)
goto error_cookie_jar;
}
- pr_notice("Loaded\n");
+ pr_notice("FS-Cache loaded\n");
return 0;
error_cookie_jar:
@@ -115,7 +106,7 @@ static void __exit fscache_exit(void)
kmem_cache_destroy(fscache_cookie_jar);
fscache_proc_cleanup();
destroy_workqueue(fscache_wq);
- pr_notice("Unloaded\n");
+ pr_notice("FS-Cache unloaded\n");
}
module_exit(fscache_exit);
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index e96432499eb2..43769ac606e8 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -9,8 +9,9 @@
#include <linux/seq_file.h>
#include <linux/netfs.h>
#include <linux/fscache.h>
+#include <linux/fscache-cache.h>
#include <trace/events/netfs.h>
-#include "fscache_internal.h"
+#include <trace/events/fscache.h>
#ifdef pr_fmt
#undef pr_fmt
@@ -106,11 +107,143 @@ static inline bool netfs_is_cache_enabled(struct netfs_inode *ctx)
#endif
}
+/*
+ * fscache-cache.c
+ */
+#ifdef CONFIG_PROC_FS
+extern const struct seq_operations fscache_caches_seq_ops;
+#endif
+bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
+void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
+struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache);
+void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where);
+
+static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache)
+{
+ return smp_load_acquire(&cache->state);
+}
+
+static inline bool fscache_cache_is_live(const struct fscache_cache *cache)
+{
+ return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE;
+}
+
+static inline void fscache_set_cache_state(struct fscache_cache *cache,
+ enum fscache_cache_state new_state)
+{
+ smp_store_release(&cache->state, new_state);
+
+}
+
+static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache,
+ enum fscache_cache_state old_state,
+ enum fscache_cache_state new_state)
+{
+ return try_cmpxchg_release(&cache->state, &old_state, new_state);
+}
+
+/*
+ * fscache-cookie.c
+ */
+extern struct kmem_cache *fscache_cookie_jar;
+#ifdef CONFIG_PROC_FS
+extern const struct seq_operations fscache_cookies_seq_ops;
+#endif
+extern struct timer_list fscache_cookie_lru_timer;
+
+extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix);
+extern bool fscache_begin_cookie_access(struct fscache_cookie *cookie,
+ enum fscache_access_trace why);
+
+static inline void fscache_see_cookie(struct fscache_cookie *cookie,
+ enum fscache_cookie_trace where)
+{
+ trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
+ where);
+}
+
+/*
+ * fscache-main.c
+ */
+extern unsigned int fscache_hash(unsigned int salt, const void *data, size_t len);
+
+/*
+ * fscache-proc.c
+ */
+#ifdef CONFIG_PROC_FS
+extern int __init fscache_proc_init(void);
+extern void fscache_proc_cleanup(void);
+#else
+#define fscache_proc_init() (0)
+#define fscache_proc_cleanup() do {} while (0)
+#endif
+
+/*
+ * fscache-stats.c
+ */
+#ifdef CONFIG_FSCACHE_STATS
+extern atomic_t fscache_n_volumes;
+extern atomic_t fscache_n_volumes_collision;
+extern atomic_t fscache_n_volumes_nomem;
+extern atomic_t fscache_n_cookies;
+extern atomic_t fscache_n_cookies_lru;
+extern atomic_t fscache_n_cookies_lru_expired;
+extern atomic_t fscache_n_cookies_lru_removed;
+extern atomic_t fscache_n_cookies_lru_dropped;
+
+extern atomic_t fscache_n_acquires;
+extern atomic_t fscache_n_acquires_ok;
+extern atomic_t fscache_n_acquires_oom;
+
+extern atomic_t fscache_n_invalidates;
+
+extern atomic_t fscache_n_relinquishes;
+extern atomic_t fscache_n_relinquishes_retire;
+extern atomic_t fscache_n_relinquishes_dropped;
+
+extern atomic_t fscache_n_resizes;
+extern atomic_t fscache_n_resizes_null;
+
+static inline void fscache_stat(atomic_t *stat)
+{
+ atomic_inc(stat);
+}
+
+static inline void fscache_stat_d(atomic_t *stat)
+{
+ atomic_dec(stat);
+}
+
+#define __fscache_stat(stat) (stat)
+
+int fscache_stats_show(struct seq_file *m, void *v);
+#else
+
+#define __fscache_stat(stat) (NULL)
+#define fscache_stat(stat) do {} while (0)
+#define fscache_stat_d(stat) do {} while (0)
+#endif
+
+/*
+ * fscache-volume.c
+ */
+#ifdef CONFIG_PROC_FS
+extern const struct seq_operations fscache_volumes_seq_ops;
+#endif
+
+struct fscache_volume *fscache_get_volume(struct fscache_volume *volume,
+ enum fscache_volume_trace where);
+void fscache_put_volume(struct fscache_volume *volume,
+ enum fscache_volume_trace where);
+bool fscache_begin_volume_access(struct fscache_volume *volume,
+ struct fscache_cookie *cookie,
+ enum fscache_access_trace why);
+void fscache_create_volume(struct fscache_volume *volume, bool wait);
+
/*****************************************************************************/
/*
* debug tracing
*/
-#if 0
#define dbgprintk(FMT, ...) \
printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
@@ -147,4 +280,57 @@ do { \
#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
#endif
-#endif
+
+/*
+ * assertions
+ */
+#if 1 /* defined(__KDEBUGALL) */
+
+#define ASSERT(X) \
+do { \
+ if (unlikely(!(X))) { \
+ pr_err("\n"); \
+ pr_err("Assertion failed\n"); \
+ BUG(); \
+ } \
+} while (0)
+
+#define ASSERTCMP(X, OP, Y) \
+do { \
+ if (unlikely(!((X) OP (Y)))) { \
+ pr_err("\n"); \
+ pr_err("Assertion failed\n"); \
+ pr_err("%lx " #OP " %lx is false\n", \
+ (unsigned long)(X), (unsigned long)(Y)); \
+ BUG(); \
+ } \
+} while (0)
+
+#define ASSERTIF(C, X) \
+do { \
+ if (unlikely((C) && !(X))) { \
+ pr_err("\n"); \
+ pr_err("Assertion failed\n"); \
+ BUG(); \
+ } \
+} while (0)
+
+#define ASSERTIFCMP(C, X, OP, Y) \
+do { \
+ if (unlikely((C) && !((X) OP (Y)))) { \
+ pr_err("\n"); \
+ pr_err("Assertion failed\n"); \
+ pr_err("%lx " #OP " %lx is false\n", \
+ (unsigned long)(X), (unsigned long)(Y)); \
+ BUG(); \
+ } \
+} while (0)
+
+#else
+
+#define ASSERT(X) do {} while (0)
+#define ASSERTCMP(X, OP, Y) do {} while (0)
+#define ASSERTIF(C, X) do {} while (0)
+#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
+
+#endif /* assert or not */
diff --git a/fs/netfs/main.c b/fs/netfs/main.c
index 237c54a01d97..1ba8091fcf3e 100644
--- a/fs/netfs/main.c
+++ b/fs/netfs/main.c
@@ -8,8 +8,8 @@
#include <linux/module.h>
#include <linux/export.h>
#include "internal.h"
-//#define CREATE_TRACE_POINTS
-//#include <trace/events/netfs.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/netfs.h>
MODULE_DESCRIPTION("Network fs support");
MODULE_AUTHOR("Red Hat, Inc.");
diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index 01ac733a6320..f7e32d76e34d 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -169,8 +169,8 @@ config ROOT_NFS
config NFS_FSCACHE
bool "Provide NFS client caching support"
- depends on NFS_FS=m && FSCACHE || NFS_FS=y && FSCACHE=y
- select NETFS_SUPPORT
+ depends on NFS_FS=m && NETFS_SUPPORT || NFS_FS=y && NETFS_SUPPORT=y
+ select FSCACHE
help
Say Y here if you want NFS data to be cached locally on disc through
the general filesystem cache manager
Move the resource pinning-for-writeback from fscache code to netfslib code.
This is used to keep a cache backing object pinned whilst we have dirty
pages on the netfs inode in the pagecache such that VM writeback will be
able to reach it.
Whilst we're at it, switch the parameters of netfs_unpin_writeback() to
match ->write_inode() so that it can be used for that directly.
Note that this mechanism could be more generically useful than that for
network filesystems. Quite often they have to keep around other resources
(e.g. authentication tokens or network connections) until the writeback is
complete.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/9p/vfs_addr.c | 33 ++++-----------
fs/9p/vfs_inode.c | 3 +-
fs/9p/vfs_super.c | 14 +------
fs/afs/file.c | 8 +---
fs/afs/inode.c | 2 +-
fs/afs/internal.h | 6 ---
fs/afs/super.c | 2 +-
fs/afs/write.c | 9 ----
fs/ceph/cache.h | 23 ++++-------
fs/ceph/inode.c | 2 +-
fs/fs-writeback.c | 10 ++---
fs/netfs/Makefile | 1 +
fs/netfs/fscache_io.c | 40 ------------------
fs/netfs/misc.c | 86 +++++++++++++++++++++++++++++++++++++++
fs/smb/client/cifsfs.c | 5 +--
fs/smb/client/file.c | 18 +-------
include/linux/fs.h | 2 +-
include/linux/fscache.h | 42 -------------------
include/linux/netfs.h | 3 ++
include/linux/writeback.h | 2 +-
20 files changed, 124 insertions(+), 187 deletions(-)
create mode 100644 fs/netfs/misc.c
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 39db7c01e30a..131b83c31f85 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -317,30 +317,15 @@ static int v9fs_write_end(struct file *filp, struct address_space *mapping,
return copied;
}
-#ifdef CONFIG_9P_FSCACHE
-/*
- * Mark a page as having been made dirty and thus needing writeback. We also
- * need to pin the cache object to write back to.
- */
-static bool v9fs_dirty_folio(struct address_space *mapping, struct folio *folio)
-{
- struct v9fs_inode *v9inode = V9FS_I(mapping->host);
-
- return fscache_dirty_folio(mapping, folio, v9fs_inode_cookie(v9inode));
-}
-#else
-#define v9fs_dirty_folio filemap_dirty_folio
-#endif
-
const struct address_space_operations v9fs_addr_operations = {
- .read_folio = netfs_read_folio,
- .readahead = netfs_readahead,
- .dirty_folio = v9fs_dirty_folio,
- .writepage = v9fs_vfs_writepage,
- .write_begin = v9fs_write_begin,
- .write_end = v9fs_write_end,
- .release_folio = v9fs_release_folio,
+ .read_folio = netfs_read_folio,
+ .readahead = netfs_readahead,
+ .dirty_folio = netfs_dirty_folio,
+ .writepage = v9fs_vfs_writepage,
+ .write_begin = v9fs_write_begin,
+ .write_end = v9fs_write_end,
+ .release_folio = v9fs_release_folio,
.invalidate_folio = v9fs_invalidate_folio,
- .launder_folio = v9fs_launder_folio,
- .direct_IO = v9fs_direct_IO,
+ .launder_folio = v9fs_launder_folio,
+ .direct_IO = v9fs_direct_IO,
};
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index b845ee18a80b..74122540e00f 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -376,8 +376,7 @@ void v9fs_evict_inode(struct inode *inode)
#ifdef CONFIG_9P_FSCACHE
version = cpu_to_le32(v9inode->qid.version);
- fscache_clear_inode_writeback(v9fs_inode_cookie(v9inode), inode,
- &version);
+ netfs_clear_inode_writeback(inode, &version);
#endif
clear_inode(inode);
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index 73db55c050bf..941f7d0e0bfa 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -289,31 +289,21 @@ static int v9fs_drop_inode(struct inode *inode)
static int v9fs_write_inode(struct inode *inode,
struct writeback_control *wbc)
{
- struct v9fs_inode *v9inode;
-
/*
* send an fsync request to server irrespective of
* wbc->sync_mode.
*/
p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
-
- v9inode = V9FS_I(inode);
- fscache_unpin_writeback(wbc, v9fs_inode_cookie(v9inode));
-
- return 0;
+ return netfs_unpin_writeback(inode, wbc);
}
static int v9fs_write_inode_dotl(struct inode *inode,
struct writeback_control *wbc)
{
- struct v9fs_inode *v9inode;
- v9inode = V9FS_I(inode);
p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode);
- fscache_unpin_writeback(wbc, v9fs_inode_cookie(v9inode));
-
- return 0;
+ return netfs_unpin_writeback(inode, wbc);
}
static const struct super_operations v9fs_super_ops = {
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 8c17e37c2e59..9142fda7dbd6 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -55,7 +55,7 @@ const struct inode_operations afs_file_inode_operations = {
const struct address_space_operations afs_file_aops = {
.read_folio = netfs_read_folio,
.readahead = netfs_readahead,
- .dirty_folio = afs_dirty_folio,
+ .dirty_folio = netfs_dirty_folio,
.launder_folio = afs_launder_folio,
.release_folio = afs_release_folio,
.invalidate_folio = afs_invalidate_folio,
@@ -386,12 +386,6 @@ const struct netfs_request_ops afs_req_ops = {
.issue_read = afs_issue_read,
};
-int afs_write_inode(struct inode *inode, struct writeback_control *wbc)
-{
- fscache_unpin_writeback(wbc, afs_vnode_cache(AFS_FS_I(inode)));
- return 0;
-}
-
/*
* Adjust the dirty region of the page on truncation or full invalidation,
* getting rid of the markers altogether if the region is entirely invalidated.
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 78efc9719349..6f375f0cf650 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -823,7 +823,7 @@ void afs_evict_inode(struct inode *inode)
truncate_inode_pages_final(&inode->i_data);
afs_set_cache_aux(vnode, &aux);
- fscache_clear_inode_writeback(afs_vnode_cache(vnode), inode, &aux);
+ netfs_clear_inode_writeback(inode, &aux);
clear_inode(inode);
while (!list_empty(&vnode->wb_keys)) {
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index a812952be1c9..2bea59ec533e 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -1072,7 +1072,6 @@ extern int afs_release(struct inode *, struct file *);
extern int afs_fetch_data(struct afs_vnode *, struct afs_read *);
extern struct afs_read *afs_alloc_read(gfp_t);
extern void afs_put_read(struct afs_read *);
-extern int afs_write_inode(struct inode *, struct writeback_control *);
static inline struct afs_read *afs_get_read(struct afs_read *req)
{
@@ -1520,11 +1519,6 @@ extern int afs_check_volume_status(struct afs_volume *, struct afs_operation *);
/*
* write.c
*/
-#ifdef CONFIG_AFS_FSCACHE
-bool afs_dirty_folio(struct address_space *, struct folio *);
-#else
-#define afs_dirty_folio filemap_dirty_folio
-#endif
extern int afs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len,
struct page **pagep, void **fsdata);
diff --git a/fs/afs/super.c b/fs/afs/super.c
index a01a0fb2cdbb..4f1b0492f1c5 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -55,7 +55,7 @@ int afs_net_id;
static const struct super_operations afs_super_ops = {
.statfs = afs_statfs,
.alloc_inode = afs_alloc_inode,
- .write_inode = afs_write_inode,
+ .write_inode = netfs_unpin_writeback,
.drop_inode = afs_drop_inode,
.destroy_inode = afs_destroy_inode,
.free_inode = afs_free_inode,
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 4a168781936b..e40cf8e7543a 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -23,15 +23,6 @@ static void afs_write_to_cache(struct afs_vnode *vnode, loff_t start, size_t len
loff_t i_size, bool caching);
#ifdef CONFIG_AFS_FSCACHE
-/*
- * Mark a page as having been made dirty and thus needing writeback. We also
- * need to pin the cache object to write back to.
- */
-bool afs_dirty_folio(struct address_space *mapping, struct folio *folio)
-{
- return fscache_dirty_folio(mapping, folio,
- afs_vnode_cache(AFS_FS_I(mapping->host)));
-}
static void afs_folio_start_fscache(bool caching, struct folio *folio)
{
if (caching)
diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
index b804f1094764..8fc7d828d990 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -43,19 +43,13 @@ static inline void ceph_fscache_resize(struct inode *inode, loff_t to)
}
}
-static inline void ceph_fscache_unpin_writeback(struct inode *inode,
+static inline int ceph_fscache_unpin_writeback(struct inode *inode,
struct writeback_control *wbc)
{
- fscache_unpin_writeback(wbc, ceph_fscache_cookie(ceph_inode(inode)));
+ return netfs_unpin_writeback(inode, wbc);
}
-static inline int ceph_fscache_dirty_folio(struct address_space *mapping,
- struct folio *folio)
-{
- struct ceph_inode_info *ci = ceph_inode(mapping->host);
-
- return fscache_dirty_folio(mapping, folio, ceph_fscache_cookie(ci));
-}
+#define ceph_fscache_dirty_folio netfs_dirty_folio
static inline bool ceph_is_cache_enabled(struct inode *inode)
{
@@ -112,16 +106,13 @@ static inline void ceph_fscache_resize(struct inode *inode, loff_t to)
{
}
-static inline void ceph_fscache_unpin_writeback(struct inode *inode,
- struct writeback_control *wbc)
+static inline int ceph_fscache_unpin_writeback(struct inode *inode,
+ struct writeback_control *wbc)
{
+ return 0;
}
-static inline int ceph_fscache_dirty_folio(struct address_space *mapping,
- struct folio *folio)
-{
- return filemap_dirty_folio(mapping, folio);
-}
+#define ceph_fscache_dirty_folio filemap_dirty_folio
static inline bool ceph_is_cache_enabled(struct inode *inode)
{
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 0679240f06db..3149d79a9dbe 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -694,7 +694,7 @@ void ceph_evict_inode(struct inode *inode)
percpu_counter_dec(&mdsc->metric.total_inodes);
truncate_inode_pages_final(&inode->i_data);
- if (inode->i_state & I_PINNING_FSCACHE_WB)
+ if (inode->i_state & I_PINNING_NETFS_WB)
ceph_fscache_unuse_cookie(inode, true);
clear_inode(inode);
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 1767493dffda..3d84fcc471c6 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1675,11 +1675,11 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
inode->i_state |= I_DIRTY_PAGES;
- else if (unlikely(inode->i_state & I_PINNING_FSCACHE_WB)) {
+ else if (unlikely(inode->i_state & I_PINNING_NETFS_WB)) {
if (!(inode->i_state & I_DIRTY_PAGES)) {
- inode->i_state &= ~I_PINNING_FSCACHE_WB;
- wbc->unpinned_fscache_wb = true;
- dirty |= I_PINNING_FSCACHE_WB; /* Cause write_inode */
+ inode->i_state &= ~I_PINNING_NETFS_WB;
+ wbc->unpinned_netfs_wb = true;
+ dirty |= I_PINNING_NETFS_WB; /* Cause write_inode */
}
}
@@ -1691,7 +1691,7 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
if (ret == 0)
ret = err;
}
- wbc->unpinned_fscache_wb = false;
+ wbc->unpinned_netfs_wb = false;
trace_writeback_single_inode(inode, wbc, nr_to_write);
return ret;
}
diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
index b57162ef9cfb..a84fe9bbd3c4 100644
--- a/fs/netfs/Makefile
+++ b/fs/netfs/Makefile
@@ -5,6 +5,7 @@ netfs-y := \
io.o \
iterator.o \
main.o \
+ misc.o \
objects.o
netfs-$(CONFIG_NETFS_STATS) += stats.o
diff --git a/fs/netfs/fscache_io.c b/fs/netfs/fscache_io.c
index 0d2b8dec8f82..79171a687930 100644
--- a/fs/netfs/fscache_io.c
+++ b/fs/netfs/fscache_io.c
@@ -158,46 +158,6 @@ int __fscache_begin_write_operation(struct netfs_cache_resources *cres,
}
EXPORT_SYMBOL(__fscache_begin_write_operation);
-/**
- * fscache_dirty_folio - Mark folio dirty and pin a cache object for writeback
- * @mapping: The mapping the folio belongs to.
- * @folio: The folio being dirtied.
- * @cookie: The cookie referring to the cache object
- *
- * Set the dirty flag on a folio and pin an in-use cache object in memory
- * so that writeback can later write to it. This is intended
- * to be called from the filesystem's ->dirty_folio() method.
- *
- * Return: true if the dirty flag was set on the folio, false otherwise.
- */
-bool fscache_dirty_folio(struct address_space *mapping, struct folio *folio,
- struct fscache_cookie *cookie)
-{
- struct inode *inode = mapping->host;
- bool need_use = false;
-
- _enter("");
-
- if (!filemap_dirty_folio(mapping, folio))
- return false;
- if (!fscache_cookie_valid(cookie))
- return true;
-
- if (!(inode->i_state & I_PINNING_FSCACHE_WB)) {
- spin_lock(&inode->i_lock);
- if (!(inode->i_state & I_PINNING_FSCACHE_WB)) {
- inode->i_state |= I_PINNING_FSCACHE_WB;
- need_use = true;
- }
- spin_unlock(&inode->i_lock);
-
- if (need_use)
- fscache_use_cookie(cookie, true);
- }
- return true;
-}
-EXPORT_SYMBOL(fscache_dirty_folio);
-
struct fscache_write_request {
struct netfs_cache_resources cache_resources;
struct address_space *mapping;
diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c
new file mode 100644
index 000000000000..68baf55c47a4
--- /dev/null
+++ b/fs/netfs/misc.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Miscellaneous routines.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells ([email protected])
+ */
+
+#include <linux/swap.h>
+#include "internal.h"
+
+/**
+ * netfs_dirty_folio - Mark folio dirty and pin a cache object for writeback
+ * @mapping: The mapping the folio belongs to.
+ * @folio: The folio being dirtied.
+ *
+ * Set the dirty flag on a folio and pin an in-use cache object in memory so
+ * that writeback can later write to it. This is intended to be called from
+ * the filesystem's ->dirty_folio() method.
+ *
+ * Return: true if the dirty flag was set on the folio, false otherwise.
+ */
+bool netfs_dirty_folio(struct address_space *mapping, struct folio *folio)
+{
+ struct inode *inode = mapping->host;
+ struct netfs_inode *ictx = netfs_inode(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(ictx);
+ bool need_use = false;
+
+ _enter("");
+
+ if (!filemap_dirty_folio(mapping, folio))
+ return false;
+ if (!fscache_cookie_valid(cookie))
+ return true;
+
+ if (!(inode->i_state & I_PINNING_NETFS_WB)) {
+ spin_lock(&inode->i_lock);
+ if (!(inode->i_state & I_PINNING_NETFS_WB)) {
+ inode->i_state |= I_PINNING_NETFS_WB;
+ need_use = true;
+ }
+ spin_unlock(&inode->i_lock);
+
+ if (need_use)
+ fscache_use_cookie(cookie, true);
+ }
+ return true;
+}
+EXPORT_SYMBOL(netfs_dirty_folio);
+
+/**
+ * netfs_unpin_writeback - Unpin writeback resources
+ * @inode: The inode on which the cookie resides
+ * @wbc: The writeback control
+ *
+ * Unpin the writeback resources pinned by netfs_dirty_folio(). This is
+ * intended to be called as/by the netfs's ->write_inode() method.
+ */
+int netfs_unpin_writeback(struct inode *inode, struct writeback_control *wbc)
+{
+ struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
+
+ if (wbc->unpinned_netfs_wb)
+ fscache_unuse_cookie(cookie, NULL, NULL);
+ return 0;
+}
+EXPORT_SYMBOL(netfs_unpin_writeback);
+
+/**
+ * netfs_clear_inode_writeback - Clear writeback resources pinned by an inode
+ * @inode: The inode to clean up
+ * @aux: Auxiliary data to apply to the inode
+ *
+ * Clear any writeback resources held by an inode when the inode is evicted.
+ * This must be called before clear_inode() is called.
+ */
+void netfs_clear_inode_writeback(struct inode *inode, const void *aux)
+{
+ struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
+
+ if (inode->i_state & I_PINNING_NETFS_WB) {
+ loff_t i_size = i_size_read(inode);
+ fscache_unuse_cookie(cookie, aux, &i_size);
+ }
+}
+EXPORT_SYMBOL(netfs_clear_inode_writeback);
diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index 2131638f26d0..96a65cf9b5ec 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -429,7 +429,7 @@ static void
cifs_evict_inode(struct inode *inode)
{
truncate_inode_pages_final(&inode->i_data);
- if (inode->i_state & I_PINNING_FSCACHE_WB)
+ if (inode->i_state & I_PINNING_NETFS_WB)
cifs_fscache_unuse_inode_cookie(inode, true);
cifs_fscache_release_inode_cookie(inode);
clear_inode(inode);
@@ -792,8 +792,7 @@ static int cifs_show_stats(struct seq_file *s, struct dentry *root)
static int cifs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
- fscache_unpin_writeback(wbc, cifs_inode_cookie(inode));
- return 0;
+ return netfs_unpin_writeback(inode, wbc);
}
static int cifs_drop_inode(struct inode *inode)
diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index cf17e3dd703e..22be7587fcaf 100644
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -5043,27 +5043,13 @@ static void cifs_swap_deactivate(struct file *file)
/* do we need to unpin (or unlock) the file */
}
-/*
- * Mark a page as having been made dirty and thus needing writeback. We also
- * need to pin the cache object to write back to.
- */
-#ifdef CONFIG_CIFS_FSCACHE
-static bool cifs_dirty_folio(struct address_space *mapping, struct folio *folio)
-{
- return fscache_dirty_folio(mapping, folio,
- cifs_inode_cookie(mapping->host));
-}
-#else
-#define cifs_dirty_folio filemap_dirty_folio
-#endif
-
const struct address_space_operations cifs_addr_ops = {
.read_folio = cifs_read_folio,
.readahead = cifs_readahead,
.writepages = cifs_writepages,
.write_begin = cifs_write_begin,
.write_end = cifs_write_end,
- .dirty_folio = cifs_dirty_folio,
+ .dirty_folio = netfs_dirty_folio,
.release_folio = cifs_release_folio,
.direct_IO = cifs_direct_io,
.invalidate_folio = cifs_invalidate_folio,
@@ -5087,7 +5073,7 @@ const struct address_space_operations cifs_addr_ops_smallbuf = {
.writepages = cifs_writepages,
.write_begin = cifs_write_begin,
.write_end = cifs_write_end,
- .dirty_folio = cifs_dirty_folio,
+ .dirty_folio = netfs_dirty_folio,
.release_folio = cifs_release_folio,
.invalidate_folio = cifs_invalidate_folio,
.launder_folio = cifs_launder_folio,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 98b7a7a8c42e..68a957261694 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2294,7 +2294,7 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src,
#define I_CREATING (1 << 15)
#define I_DONTCACHE (1 << 16)
#define I_SYNC_QUEUED (1 << 17)
-#define I_PINNING_FSCACHE_WB (1 << 18)
+#define I_PINNING_NETFS_WB (1 << 18)
#define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC)
#define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES)
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index 9ed6696aee7a..6e8562cbcc43 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -626,48 +626,6 @@ static inline void fscache_write_to_cache(struct fscache_cookie *cookie,
}
-#if __fscache_available
-bool fscache_dirty_folio(struct address_space *mapping, struct folio *folio,
- struct fscache_cookie *cookie);
-#else
-#define fscache_dirty_folio(MAPPING, FOLIO, COOKIE) \
- filemap_dirty_folio(MAPPING, FOLIO)
-#endif
-
-/**
- * fscache_unpin_writeback - Unpin writeback resources
- * @wbc: The writeback control
- * @cookie: The cookie referring to the cache object
- *
- * Unpin the writeback resources pinned by fscache_dirty_folio(). This is
- * intended to be called by the netfs's ->write_inode() method.
- */
-static inline void fscache_unpin_writeback(struct writeback_control *wbc,
- struct fscache_cookie *cookie)
-{
- if (wbc->unpinned_fscache_wb)
- fscache_unuse_cookie(cookie, NULL, NULL);
-}
-
-/**
- * fscache_clear_inode_writeback - Clear writeback resources pinned by an inode
- * @cookie: The cookie referring to the cache object
- * @inode: The inode to clean up
- * @aux: Auxiliary data to apply to the inode
- *
- * Clear any writeback resources held by an inode when the inode is evicted.
- * This must be called before clear_inode() is called.
- */
-static inline void fscache_clear_inode_writeback(struct fscache_cookie *cookie,
- struct inode *inode,
- const void *aux)
-{
- if (inode->i_state & I_PINNING_FSCACHE_WB) {
- loff_t i_size = i_size_read(inode);
- fscache_unuse_cookie(cookie, aux, &i_size);
- }
-}
-
/**
* fscache_note_page_release - Note that a netfs page got released
* @cookie: The cookie corresponding to the file
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 9bd91cd615d5..32faf6c89702 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -288,6 +288,9 @@ int netfs_read_folio(struct file *, struct folio *);
int netfs_write_begin(struct netfs_inode *, struct file *,
struct address_space *, loff_t pos, unsigned int len,
struct folio **, void **fsdata);
+bool netfs_dirty_folio(struct address_space *mapping, struct folio *folio);
+int netfs_unpin_writeback(struct inode *inode, struct writeback_control *wbc);
+void netfs_clear_inode_writeback(struct inode *inode, const void *aux);
void netfs_subreq_terminated(struct netfs_io_subrequest *, ssize_t, bool);
void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 083387c00f0c..1e08392fb43e 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -60,7 +60,7 @@ struct writeback_control {
unsigned for_reclaim:1; /* Invoked from the page allocator */
unsigned range_cyclic:1; /* range_start is cyclic */
unsigned for_sync:1; /* sync(2) WB_SYNC_ALL writeback */
- unsigned unpinned_fscache_wb:1; /* Cleared I_PINNING_FSCACHE_WB */
+ unsigned unpinned_netfs_wb:1; /* Cleared I_PINNING_NETFS_WB */
/*
* When writeback IOs are bounced through async layers, only the
AFS currently uses folio->private to store the range of bytes within a
folio that have been modified - the idea being that if we have, say, a 2MiB
folio and someone writes a single byte, we only have to write back that
single page and not the whole 2MiB folio - thereby saving on network
bandwidth.
Remove this, at least for now, and accept the extra network load (which
doesn't matter in the common case of writing a whole file at a time from
beginning to end).
This makes folio->private available for netfslib to use.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/afs/file.c | 67 -------------
fs/afs/internal.h | 56 -----------
fs/afs/write.c | 188 ++++++++-----------------------------
include/trace/events/afs.h | 16 +---
4 files changed, 42 insertions(+), 285 deletions(-)
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 9142fda7dbd6..0d783e5b2147 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -386,63 +386,6 @@ const struct netfs_request_ops afs_req_ops = {
.issue_read = afs_issue_read,
};
-/*
- * Adjust the dirty region of the page on truncation or full invalidation,
- * getting rid of the markers altogether if the region is entirely invalidated.
- */
-static void afs_invalidate_dirty(struct folio *folio, size_t offset,
- size_t length)
-{
- struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio));
- unsigned long priv;
- unsigned int f, t, end = offset + length;
-
- priv = (unsigned long)folio_get_private(folio);
-
- /* we clean up only if the entire page is being invalidated */
- if (offset == 0 && length == folio_size(folio))
- goto full_invalidate;
-
- /* If the page was dirtied by page_mkwrite(), the PTE stays writable
- * and we don't get another notification to tell us to expand it
- * again.
- */
- if (afs_is_folio_dirty_mmapped(priv))
- return;
-
- /* We may need to shorten the dirty region */
- f = afs_folio_dirty_from(folio, priv);
- t = afs_folio_dirty_to(folio, priv);
-
- if (t <= offset || f >= end)
- return; /* Doesn't overlap */
-
- if (f < offset && t > end)
- return; /* Splits the dirty region - just absorb it */
-
- if (f >= offset && t <= end)
- goto undirty;
-
- if (f < offset)
- t = offset;
- else
- f = end;
- if (f == t)
- goto undirty;
-
- priv = afs_folio_dirty(folio, f, t);
- folio_change_private(folio, (void *)priv);
- trace_afs_folio_dirty(vnode, tracepoint_string("trunc"), folio);
- return;
-
-undirty:
- trace_afs_folio_dirty(vnode, tracepoint_string("undirty"), folio);
- folio_clear_dirty_for_io(folio);
-full_invalidate:
- trace_afs_folio_dirty(vnode, tracepoint_string("inval"), folio);
- folio_detach_private(folio);
-}
-
/*
* invalidate part or all of a page
* - release a page and clean up its private data if offset is 0 (indicating
@@ -453,11 +396,6 @@ static void afs_invalidate_folio(struct folio *folio, size_t offset,
{
_enter("{%lu},%zu,%zu", folio->index, offset, length);
- BUG_ON(!folio_test_locked(folio));
-
- if (folio_get_private(folio))
- afs_invalidate_dirty(folio, offset, length);
-
folio_wait_fscache(folio);
_leave("");
}
@@ -485,11 +423,6 @@ static bool afs_release_folio(struct folio *folio, gfp_t gfp)
fscache_note_page_release(afs_vnode_cache(vnode));
#endif
- if (folio_test_private(folio)) {
- trace_afs_folio_dirty(vnode, tracepoint_string("rel"), folio);
- folio_detach_private(folio);
- }
-
/* Indicate that the folio can be released */
_leave(" = T");
return true;
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 2bea59ec533e..b60fc1067381 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -893,62 +893,6 @@ static inline void afs_invalidate_cache(struct afs_vnode *vnode, unsigned int fl
i_size_read(&vnode->netfs.inode), flags);
}
-/*
- * We use folio->private to hold the amount of the folio that we've written to,
- * splitting the field into two parts. However, we need to represent a range
- * 0...FOLIO_SIZE, so we reduce the resolution if the size of the folio
- * exceeds what we can encode.
- */
-#ifdef CONFIG_64BIT
-#define __AFS_FOLIO_PRIV_MASK 0x7fffffffUL
-#define __AFS_FOLIO_PRIV_SHIFT 32
-#define __AFS_FOLIO_PRIV_MMAPPED 0x80000000UL
-#else
-#define __AFS_FOLIO_PRIV_MASK 0x7fffUL
-#define __AFS_FOLIO_PRIV_SHIFT 16
-#define __AFS_FOLIO_PRIV_MMAPPED 0x8000UL
-#endif
-
-static inline unsigned int afs_folio_dirty_resolution(struct folio *folio)
-{
- int shift = folio_shift(folio) - (__AFS_FOLIO_PRIV_SHIFT - 1);
- return (shift > 0) ? shift : 0;
-}
-
-static inline size_t afs_folio_dirty_from(struct folio *folio, unsigned long priv)
-{
- unsigned long x = priv & __AFS_FOLIO_PRIV_MASK;
-
- /* The lower bound is inclusive */
- return x << afs_folio_dirty_resolution(folio);
-}
-
-static inline size_t afs_folio_dirty_to(struct folio *folio, unsigned long priv)
-{
- unsigned long x = (priv >> __AFS_FOLIO_PRIV_SHIFT) & __AFS_FOLIO_PRIV_MASK;
-
- /* The upper bound is immediately beyond the region */
- return (x + 1) << afs_folio_dirty_resolution(folio);
-}
-
-static inline unsigned long afs_folio_dirty(struct folio *folio, size_t from, size_t to)
-{
- unsigned int res = afs_folio_dirty_resolution(folio);
- from >>= res;
- to = (to - 1) >> res;
- return (to << __AFS_FOLIO_PRIV_SHIFT) | from;
-}
-
-static inline unsigned long afs_folio_dirty_mmapped(unsigned long priv)
-{
- return priv | __AFS_FOLIO_PRIV_MMAPPED;
-}
-
-static inline bool afs_is_folio_dirty_mmapped(unsigned long priv)
-{
- return priv & __AFS_FOLIO_PRIV_MMAPPED;
-}
-
#include <trace/events/afs.h>
/*****************************************************************************/
diff --git a/fs/afs/write.c b/fs/afs/write.c
index e40cf8e7543a..80daf28d8f8b 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -16,7 +16,8 @@
static int afs_writepages_region(struct address_space *mapping,
struct writeback_control *wbc,
- loff_t start, loff_t end, loff_t *_next,
+ unsigned long long start,
+ unsigned long long end, loff_t *_next,
bool max_one_loop);
static void afs_write_to_cache(struct afs_vnode *vnode, loff_t start, size_t len,
@@ -34,25 +35,6 @@ static void afs_folio_start_fscache(bool caching, struct folio *folio)
}
#endif
-/*
- * Flush out a conflicting write. This may extend the write to the surrounding
- * pages if also dirty and contiguous to the conflicting region..
- */
-static int afs_flush_conflicting_write(struct address_space *mapping,
- struct folio *folio)
-{
- struct writeback_control wbc = {
- .sync_mode = WB_SYNC_ALL,
- .nr_to_write = LONG_MAX,
- .range_start = folio_pos(folio),
- .range_end = LLONG_MAX,
- };
- loff_t next;
-
- return afs_writepages_region(mapping, &wbc, folio_pos(folio), LLONG_MAX,
- &next, true);
-}
-
/*
* prepare to perform part of a write to a page
*/
@@ -62,10 +44,6 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
{
struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
struct folio *folio;
- unsigned long priv;
- unsigned f, from;
- unsigned t, to;
- pgoff_t index;
int ret;
_enter("{%llx:%llu},%llx,%x",
@@ -79,49 +57,20 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
if (ret < 0)
return ret;
- index = folio_index(folio);
- from = pos - index * PAGE_SIZE;
- to = from + len;
-
try_again:
/* See if this page is already partially written in a way that we can
* merge the new write with.
*/
- if (folio_test_private(folio)) {
- priv = (unsigned long)folio_get_private(folio);
- f = afs_folio_dirty_from(folio, priv);
- t = afs_folio_dirty_to(folio, priv);
- ASSERTCMP(f, <=, t);
-
- if (folio_test_writeback(folio)) {
- trace_afs_folio_dirty(vnode, tracepoint_string("alrdy"), folio);
- folio_unlock(folio);
- goto wait_for_writeback;
- }
- /* If the file is being filled locally, allow inter-write
- * spaces to be merged into writes. If it's not, only write
- * back what the user gives us.
- */
- if (!test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags) &&
- (to < f || from > t))
- goto flush_conflicting_write;
+ if (folio_test_writeback(folio)) {
+ trace_afs_folio_dirty(vnode, tracepoint_string("alrdy"), folio);
+ folio_unlock(folio);
+ goto wait_for_writeback;
}
*_page = folio_file_page(folio, pos / PAGE_SIZE);
_leave(" = 0");
return 0;
- /* The previous write and this write aren't adjacent or overlapping, so
- * flush the page out.
- */
-flush_conflicting_write:
- trace_afs_folio_dirty(vnode, tracepoint_string("confl"), folio);
- folio_unlock(folio);
-
- ret = afs_flush_conflicting_write(mapping, folio);
- if (ret < 0)
- goto error;
-
wait_for_writeback:
ret = folio_wait_writeback_killable(folio);
if (ret < 0)
@@ -147,9 +96,6 @@ int afs_write_end(struct file *file, struct address_space *mapping,
{
struct folio *folio = page_folio(subpage);
struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
- unsigned long priv;
- unsigned int f, from = offset_in_folio(folio, pos);
- unsigned int t, to = from + copied;
loff_t i_size, write_end_pos;
_enter("{%llx:%llu},{%lx}",
@@ -179,23 +125,6 @@ int afs_write_end(struct file *file, struct address_space *mapping,
fscache_update_cookie(afs_vnode_cache(vnode), NULL, &write_end_pos);
}
- if (folio_test_private(folio)) {
- priv = (unsigned long)folio_get_private(folio);
- f = afs_folio_dirty_from(folio, priv);
- t = afs_folio_dirty_to(folio, priv);
- if (from < f)
- f = from;
- if (to > t)
- t = to;
- priv = afs_folio_dirty(folio, f, t);
- folio_change_private(folio, (void *)priv);
- trace_afs_folio_dirty(vnode, tracepoint_string("dirty+"), folio);
- } else {
- priv = afs_folio_dirty(folio, from, to);
- folio_attach_private(folio, (void *)priv);
- trace_afs_folio_dirty(vnode, tracepoint_string("dirty"), folio);
- }
-
if (folio_mark_dirty(folio))
_debug("dirtied %lx", folio_index(folio));
@@ -300,7 +229,6 @@ static void afs_pages_written_back(struct afs_vnode *vnode, loff_t start, unsign
}
trace_afs_folio_dirty(vnode, tracepoint_string("clear"), folio);
- folio_detach_private(folio);
folio_end_writeback(folio);
}
@@ -454,17 +382,12 @@ static void afs_extend_writeback(struct address_space *mapping,
long *_count,
loff_t start,
loff_t max_len,
- bool new_content,
bool caching,
- unsigned int *_len)
+ size_t *_len)
{
struct folio_batch fbatch;
struct folio *folio;
- unsigned long priv;
- unsigned int psize, filler = 0;
- unsigned int f, t;
- loff_t len = *_len;
- pgoff_t index = (start + len) / PAGE_SIZE;
+ pgoff_t index = (start + *_len) / PAGE_SIZE;
bool stop = true;
unsigned int i;
@@ -492,7 +415,7 @@ static void afs_extend_writeback(struct address_space *mapping,
continue;
}
- /* Has the page moved or been split? */
+ /* Has the folio moved or been split? */
if (unlikely(folio != xas_reload(&xas))) {
folio_put(folio);
break;
@@ -510,24 +433,13 @@ static void afs_extend_writeback(struct address_space *mapping,
break;
}
- psize = folio_size(folio);
- priv = (unsigned long)folio_get_private(folio);
- f = afs_folio_dirty_from(folio, priv);
- t = afs_folio_dirty_to(folio, priv);
- if (f != 0 && !new_content) {
- folio_unlock(folio);
- folio_put(folio);
- break;
- }
-
- len += filler + t;
- filler = psize - t;
- if (len >= max_len || *_count <= 0)
+ index += folio_nr_pages(folio);
+ *_count -= folio_nr_pages(folio);
+ *_len += folio_size(folio);
+ stop = false;
+ if (*_len >= max_len || *_count <= 0)
stop = true;
- else if (t == psize || new_content)
- stop = false;
- index += folio_nr_pages(folio);
if (!folio_batch_add(&fbatch, folio))
break;
if (stop)
@@ -553,16 +465,12 @@ static void afs_extend_writeback(struct address_space *mapping,
if (folio_start_writeback(folio))
BUG();
afs_folio_start_fscache(caching, folio);
-
- *_count -= folio_nr_pages(folio);
folio_unlock(folio);
}
folio_batch_release(&fbatch);
cond_resched();
} while (!stop);
-
- *_len = len;
}
/*
@@ -572,14 +480,13 @@ static void afs_extend_writeback(struct address_space *mapping,
static ssize_t afs_write_back_from_locked_folio(struct address_space *mapping,
struct writeback_control *wbc,
struct folio *folio,
- loff_t start, loff_t end)
+ unsigned long long start,
+ unsigned long long end)
{
struct afs_vnode *vnode = AFS_FS_I(mapping->host);
struct iov_iter iter;
- unsigned long priv;
- unsigned int offset, to, len, max_len;
- loff_t i_size = i_size_read(&vnode->netfs.inode);
- bool new_content = test_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
+ unsigned long long i_size = i_size_read(&vnode->netfs.inode);
+ size_t len, max_len;
bool caching = fscache_cookie_enabled(afs_vnode_cache(vnode));
long count = wbc->nr_to_write;
int ret;
@@ -597,13 +504,9 @@ static ssize_t afs_write_back_from_locked_folio(struct address_space *mapping,
* immediately lockable, is not dirty or is missing, or we reach the
* end of the range.
*/
- priv = (unsigned long)folio_get_private(folio);
- offset = afs_folio_dirty_from(folio, priv);
- to = afs_folio_dirty_to(folio, priv);
trace_afs_folio_dirty(vnode, tracepoint_string("store"), folio);
- len = to - offset;
- start += offset;
+ len = folio_size(folio);
if (start < i_size) {
/* Trim the write to the EOF; the extra data is ignored. Also
* put an upper limit on the size of a single storedata op.
@@ -612,12 +515,10 @@ static ssize_t afs_write_back_from_locked_folio(struct address_space *mapping,
max_len = min_t(unsigned long long, max_len, end - start + 1);
max_len = min_t(unsigned long long, max_len, i_size - start);
- if (len < max_len &&
- (to == folio_size(folio) || new_content))
+ if (len < max_len)
afs_extend_writeback(mapping, vnode, &count,
- start, max_len, new_content,
- caching, &len);
- len = min_t(loff_t, len, max_len);
+ start, max_len, caching, &len);
+ len = min_t(unsigned long long, len, i_size - start);
}
/* We now have a contiguous set of dirty pages, each with writeback
@@ -627,7 +528,7 @@ static ssize_t afs_write_back_from_locked_folio(struct address_space *mapping,
folio_unlock(folio);
if (start < i_size) {
- _debug("write back %x @%llx [%llx]", len, start, i_size);
+ _debug("write back %zx @%llx [%llx]", len, start, i_size);
/* Speculatively write to the cache. We have to fix this up
* later if the store fails.
@@ -637,7 +538,7 @@ static ssize_t afs_write_back_from_locked_folio(struct address_space *mapping,
iov_iter_xarray(&iter, ITER_SOURCE, &mapping->i_pages, start, len);
ret = afs_store_data(vnode, &iter, start, false);
} else {
- _debug("write discard %x @%llx [%llx]", len, start, i_size);
+ _debug("write discard %zx @%llx [%llx]", len, start, i_size);
/* The dirty region was entirely beyond the EOF. */
fscache_clear_page_bits(mapping, start, len, caching);
@@ -693,7 +594,8 @@ static ssize_t afs_write_back_from_locked_folio(struct address_space *mapping,
*/
static int afs_writepages_region(struct address_space *mapping,
struct writeback_control *wbc,
- loff_t start, loff_t end, loff_t *_next,
+ unsigned long long start,
+ unsigned long long end, loff_t *_next,
bool max_one_loop)
{
struct folio *folio;
@@ -905,7 +807,6 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
struct inode *inode = file_inode(file);
struct afs_vnode *vnode = AFS_FS_I(inode);
struct afs_file *af = file->private_data;
- unsigned long priv;
vm_fault_t ret = VM_FAULT_RETRY;
_enter("{{%llx:%llu}},{%lx}", vnode->fid.vid, vnode->fid.vnode, folio_index(folio));
@@ -929,24 +830,15 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
if (folio_lock_killable(folio) < 0)
goto out;
- /* We mustn't change folio->private until writeback is complete as that
- * details the portion of the page we need to write back and we might
- * need to redirty the page if there's a problem.
- */
if (folio_wait_writeback_killable(folio) < 0) {
folio_unlock(folio);
goto out;
}
- priv = afs_folio_dirty(folio, 0, folio_size(folio));
- priv = afs_folio_dirty_mmapped(priv);
- if (folio_test_private(folio)) {
- folio_change_private(folio, (void *)priv);
+ if (folio_test_dirty(folio))
trace_afs_folio_dirty(vnode, tracepoint_string("mkwrite+"), folio);
- } else {
- folio_attach_private(folio, (void *)priv);
+ else
trace_afs_folio_dirty(vnode, tracepoint_string("mkwrite"), folio);
- }
file_update_time(file);
ret = VM_FAULT_LOCKED;
@@ -991,30 +883,26 @@ int afs_launder_folio(struct folio *folio)
struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio));
struct iov_iter iter;
struct bio_vec bv;
- unsigned long priv;
- unsigned int f, t;
+ unsigned long long fend, i_size = vnode->netfs.inode.i_size;
+ size_t len;
int ret = 0;
_enter("{%lx}", folio->index);
- priv = (unsigned long)folio_get_private(folio);
- if (folio_clear_dirty_for_io(folio)) {
- f = 0;
- t = folio_size(folio);
- if (folio_test_private(folio)) {
- f = afs_folio_dirty_from(folio, priv);
- t = afs_folio_dirty_to(folio, priv);
- }
+ if (folio_clear_dirty_for_io(folio) && folio_pos(folio) < i_size) {
+ len = folio_size(folio);
+ fend = folio_pos(folio) + len;
+ if (vnode->netfs.inode.i_size < fend)
+ len = fend - i_size;
- bvec_set_folio(&bv, folio, t - f, f);
- iov_iter_bvec(&iter, ITER_SOURCE, &bv, 1, bv.bv_len);
+ bvec_set_folio(&bv, folio, len, 0);
+ iov_iter_bvec(&iter, WRITE, &bv, 1, len);
trace_afs_folio_dirty(vnode, tracepoint_string("launder"), folio);
- ret = afs_store_data(vnode, &iter, folio_pos(folio) + f, true);
+ ret = afs_store_data(vnode, &iter, folio_pos(folio), true);
}
trace_afs_folio_dirty(vnode, tracepoint_string("laundered"), folio);
- folio_detach_private(folio);
folio_wait_fscache(folio);
return ret;
}
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 597677acc6b1..08506680350c 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -846,26 +846,18 @@ TRACE_EVENT(afs_folio_dirty,
__field(struct afs_vnode *, vnode)
__field(const char *, where)
__field(pgoff_t, index)
- __field(unsigned long, from)
- __field(unsigned long, to)
+ __field(size_t, size)
),
TP_fast_assign(
- unsigned long priv = (unsigned long)folio_get_private(folio);
__entry->vnode = vnode;
__entry->where = where;
__entry->index = folio_index(folio);
- __entry->from = afs_folio_dirty_from(folio, priv);
- __entry->to = afs_folio_dirty_to(folio, priv);
- __entry->to |= (afs_is_folio_dirty_mmapped(priv) ?
- (1UL << (BITS_PER_LONG - 1)) : 0);
+ __entry->size = folio_size(folio);
),
- TP_printk("vn=%p %lx %s %lx-%lx%s",
- __entry->vnode, __entry->index, __entry->where,
- __entry->from,
- __entry->to & ~(1UL << (BITS_PER_LONG - 1)),
- __entry->to & (1UL << (BITS_PER_LONG - 1)) ? " M" : "")
+ TP_printk("vn=%p ix=%05lx s=%05lx %s",
+ __entry->vnode, __entry->index, __entry->size, __entry->where)
);
TRACE_EVENT(afs_call_state,
Add three iov_iter structs:
(1) Add an iov_iter (->iter) to the I/O request to describe the
unencrypted-side buffer.
(2) Add an iov_iter (->io_iter) to the I/O request to describe the
encrypted-side I/O buffer. This may be a different size to the buffer
in (1).
(3) Add an iov_iter (->io_iter) to the I/O subrequest to describe the part
of the I/O buffer for that subrequest.
This will allow future patches to point to a bounce buffer instead for
purposes of handling oversize writes, decryption (where we want to save the
encrypted data to the cache) and decompression.
These iov_iters persist for the lifetime of the (sub)request, and so can be
accessed multiple times without worrying about them being deallocated upon
return to the caller.
The network filesystem must appropriately advance the iterator before
terminating the request.
Signed-off-by: David Howells <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/afs/file.c | 6 +---
fs/netfs/buffered_read.c | 13 ++++++++
fs/netfs/io.c | 69 +++++++++++++++++++++++++++++-----------
include/linux/netfs.h | 3 ++
4 files changed, 67 insertions(+), 24 deletions(-)
diff --git a/fs/afs/file.c b/fs/afs/file.c
index d152ba451f0e..3403bb792deb 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -323,11 +323,7 @@ static void afs_issue_read(struct netfs_io_subrequest *subreq)
fsreq->len = subreq->len - subreq->transferred;
fsreq->key = key_get(subreq->rreq->netfs_priv);
fsreq->vnode = vnode;
- fsreq->iter = &fsreq->def_iter;
-
- iov_iter_xarray(&fsreq->def_iter, ITER_DEST,
- &fsreq->vnode->netfs.inode.i_mapping->i_pages,
- fsreq->pos, fsreq->len);
+ fsreq->iter = &subreq->io_iter;
afs_fetch_data(fsreq->vnode, fsreq);
afs_put_read(fsreq);
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index d39d0ffe75d2..751556faa70b 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -199,6 +199,10 @@ void netfs_readahead(struct readahead_control *ractl)
netfs_rreq_expand(rreq, ractl);
+ /* Set up the output buffer */
+ iov_iter_xarray(&rreq->iter, ITER_DEST, &ractl->mapping->i_pages,
+ rreq->start, rreq->len);
+
/* Drop the refs on the folios here rather than in the cache or
* filesystem. The locks will be dropped in netfs_rreq_unlock().
*/
@@ -251,6 +255,11 @@ int netfs_read_folio(struct file *file, struct folio *folio)
netfs_stat(&netfs_n_rh_readpage);
trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);
+
+ /* Set up the output buffer */
+ iov_iter_xarray(&rreq->iter, ITER_DEST, &mapping->i_pages,
+ rreq->start, rreq->len);
+
return netfs_begin_read(rreq, true);
discard:
@@ -408,6 +417,10 @@ int netfs_write_begin(struct netfs_inode *ctx,
ractl._nr_pages = folio_nr_pages(folio);
netfs_rreq_expand(rreq, &ractl);
+ /* Set up the output buffer */
+ iov_iter_xarray(&rreq->iter, ITER_DEST, &mapping->i_pages,
+ rreq->start, rreq->len);
+
/* We hold the folio locks, so we can drop the references */
folio_get(folio);
while (readahead_folio(&ractl))
diff --git a/fs/netfs/io.c b/fs/netfs/io.c
index 7f753380e047..e9d408e211b8 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -21,12 +21,7 @@
*/
static void netfs_clear_unread(struct netfs_io_subrequest *subreq)
{
- struct iov_iter iter;
-
- iov_iter_xarray(&iter, ITER_DEST, &subreq->rreq->mapping->i_pages,
- subreq->start + subreq->transferred,
- subreq->len - subreq->transferred);
- iov_iter_zero(iov_iter_count(&iter), &iter);
+ iov_iter_zero(iov_iter_count(&subreq->io_iter), &subreq->io_iter);
}
static void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error,
@@ -46,14 +41,9 @@ static void netfs_read_from_cache(struct netfs_io_request *rreq,
enum netfs_read_from_hole read_hole)
{
struct netfs_cache_resources *cres = &rreq->cache_resources;
- struct iov_iter iter;
netfs_stat(&netfs_n_rh_read);
- iov_iter_xarray(&iter, ITER_DEST, &rreq->mapping->i_pages,
- subreq->start + subreq->transferred,
- subreq->len - subreq->transferred);
-
- cres->ops->read(cres, subreq->start, &iter, read_hole,
+ cres->ops->read(cres, subreq->start, &subreq->io_iter, read_hole,
netfs_cache_read_terminated, subreq);
}
@@ -88,6 +78,11 @@ static void netfs_read_from_server(struct netfs_io_request *rreq,
struct netfs_io_subrequest *subreq)
{
netfs_stat(&netfs_n_rh_download);
+ if (iov_iter_count(&subreq->io_iter) != subreq->len - subreq->transferred)
+ pr_warn("R=%08x[%u] ITER PRE-MISMATCH %zx != %zx-%zx %lx\n",
+ rreq->debug_id, subreq->debug_index,
+ iov_iter_count(&subreq->io_iter), subreq->len,
+ subreq->transferred, subreq->flags);
rreq->netfs_ops->issue_read(subreq);
}
@@ -259,6 +254,30 @@ static void netfs_rreq_short_read(struct netfs_io_request *rreq,
netfs_read_from_server(rreq, subreq);
}
+/*
+ * Reset the subrequest iterator prior to resubmission.
+ */
+static void netfs_reset_subreq_iter(struct netfs_io_request *rreq,
+ struct netfs_io_subrequest *subreq)
+{
+ size_t remaining = subreq->len - subreq->transferred;
+ size_t count = iov_iter_count(&subreq->io_iter);
+
+ if (count == remaining)
+ return;
+
+ _debug("R=%08x[%u] ITER RESUB-MISMATCH %zx != %zx-%zx-%llx %x\n",
+ rreq->debug_id, subreq->debug_index,
+ iov_iter_count(&subreq->io_iter), subreq->transferred,
+ subreq->len, rreq->i_size,
+ subreq->io_iter.iter_type);
+
+ if (count < remaining)
+ iov_iter_revert(&subreq->io_iter, remaining - count);
+ else
+ iov_iter_advance(&subreq->io_iter, count - remaining);
+}
+
/*
* Resubmit any short or failed operations. Returns true if we got the rreq
* ref back.
@@ -287,6 +306,7 @@ static bool netfs_rreq_perform_resubmissions(struct netfs_io_request *rreq)
trace_netfs_sreq(subreq, netfs_sreq_trace_download_instead);
netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit);
atomic_inc(&rreq->nr_outstanding);
+ netfs_reset_subreq_iter(rreq, subreq);
netfs_read_from_server(rreq, subreq);
} else if (test_bit(NETFS_SREQ_SHORT_IO, &subreq->flags)) {
netfs_rreq_short_read(rreq, subreq);
@@ -399,9 +419,9 @@ void netfs_subreq_terminated(struct netfs_io_subrequest *subreq,
struct netfs_io_request *rreq = subreq->rreq;
int u;
- _enter("[%u]{%llx,%lx},%zd",
- subreq->debug_index, subreq->start, subreq->flags,
- transferred_or_error);
+ _enter("R=%x[%x]{%llx,%lx},%zd",
+ rreq->debug_id, subreq->debug_index,
+ subreq->start, subreq->flags, transferred_or_error);
switch (subreq->source) {
case NETFS_READ_FROM_CACHE:
@@ -501,7 +521,8 @@ static enum netfs_io_source netfs_cache_prepare_read(struct netfs_io_subrequest
*/
static enum netfs_io_source
netfs_rreq_prepare_read(struct netfs_io_request *rreq,
- struct netfs_io_subrequest *subreq)
+ struct netfs_io_subrequest *subreq,
+ struct iov_iter *io_iter)
{
enum netfs_io_source source;
@@ -528,9 +549,14 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
}
}
- if (WARN_ON(subreq->len == 0))
+ if (WARN_ON(subreq->len == 0)) {
source = NETFS_INVALID_READ;
+ goto out;
+ }
+ subreq->io_iter = *io_iter;
+ iov_iter_truncate(&subreq->io_iter, subreq->len);
+ iov_iter_advance(io_iter, subreq->len);
out:
subreq->source = source;
trace_netfs_sreq(subreq, netfs_sreq_trace_prepare);
@@ -541,6 +567,7 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
* Slice off a piece of a read request and submit an I/O request for it.
*/
static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
+ struct iov_iter *io_iter,
unsigned int *_debug_index)
{
struct netfs_io_subrequest *subreq;
@@ -565,7 +592,7 @@ static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
* (the starts must coincide), in which case, we go around the loop
* again and ask it to download the next piece.
*/
- source = netfs_rreq_prepare_read(rreq, subreq);
+ source = netfs_rreq_prepare_read(rreq, subreq, io_iter);
if (source == NETFS_INVALID_READ)
goto subreq_failed;
@@ -603,6 +630,7 @@ static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
*/
int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
{
+ struct iov_iter io_iter;
unsigned int debug_index = 0;
int ret;
@@ -615,6 +643,8 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
return -EIO;
}
+ rreq->io_iter = rreq->iter;
+
INIT_WORK(&rreq->work, netfs_rreq_work);
if (sync)
@@ -624,8 +654,9 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
* want and submit each one.
*/
atomic_set(&rreq->nr_outstanding, 1);
+ io_iter = rreq->io_iter;
do {
- if (!netfs_rreq_submit_slice(rreq, &debug_index))
+ if (!netfs_rreq_submit_slice(rreq, &io_iter, &debug_index))
break;
} while (rreq->submitted < rreq->len);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index fc6d9756a029..3da962e977f5 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -150,6 +150,7 @@ struct netfs_cache_resources {
struct netfs_io_subrequest {
struct netfs_io_request *rreq; /* Supervising I/O request */
struct list_head rreq_link; /* Link in rreq->subrequests */
+ struct iov_iter io_iter; /* Iterator for this subrequest */
loff_t start; /* Where to start the I/O */
size_t len; /* Size of the I/O */
size_t transferred; /* Amount of data transferred */
@@ -186,6 +187,8 @@ struct netfs_io_request {
struct netfs_cache_resources cache_resources;
struct list_head proc_link; /* Link in netfs_iorequests */
struct list_head subrequests; /* Contributory I/O operations */
+ struct iov_iter iter; /* Unencrypted-side iterator */
+ struct iov_iter io_iter; /* I/O (Encrypted-side) iterator */
void *netfs_priv; /* Private data for the netfs */
unsigned int debug_id;
atomic_t nr_outstanding; /* Number of ops in progress */
Add a bvec array pointer and an iterator to netfs_io_request for either
holding a copy of a DIO iterator or a list of all the bits of buffer
pointed to by a DIO iterator.
There are two problems: Firstly, if an iovec-class iov_iter is passed to
->read_iter() or ->write_iter(), this cannot be passed directly to
kernel_sendmsg() or kernel_recvmsg() as that may cause locking recursion if
a fault is generated, so we need to keep track of the pages involved
separately.
Secondly, if the I/O is asynchronous, we must copy the iov_iter describing
the buffer before returning to the caller as it may be immediately
deallocated.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/objects.c | 10 ++++++++++
include/linux/netfs.h | 4 ++++
2 files changed, 14 insertions(+)
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index 1bd20bdad983..4df5e5eeada6 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -76,6 +76,7 @@ static void netfs_free_request(struct work_struct *work)
{
struct netfs_io_request *rreq =
container_of(work, struct netfs_io_request, work);
+ unsigned int i;
trace_netfs_rreq(rreq, netfs_rreq_trace_free);
netfs_proc_del_rreq(rreq);
@@ -84,6 +85,15 @@ static void netfs_free_request(struct work_struct *work)
rreq->netfs_ops->free_request(rreq);
if (rreq->cache_resources.ops)
rreq->cache_resources.ops->end_operation(&rreq->cache_resources);
+ if (rreq->direct_bv) {
+ for (i = 0; i < rreq->direct_bv_count; i++) {
+ if (rreq->direct_bv[i].bv_page) {
+ if (rreq->direct_bv_unpin)
+ unpin_user_page(rreq->direct_bv[i].bv_page);
+ }
+ }
+ kvfree(rreq->direct_bv);
+ }
kfree_rcu(rreq, rcu);
netfs_stat_d(&netfs_n_rh_rreq);
}
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 3da962e977f5..bbb33ccbf719 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -190,6 +190,9 @@ struct netfs_io_request {
struct iov_iter iter; /* Unencrypted-side iterator */
struct iov_iter io_iter; /* I/O (Encrypted-side) iterator */
void *netfs_priv; /* Private data for the netfs */
+ struct bio_vec *direct_bv /* DIO buffer list (when handling iovec-iter) */
+ __counted_by(direct_bv_count);
+ unsigned int direct_bv_count; /* Number of elements in direct_bv[] */
unsigned int debug_id;
atomic_t nr_outstanding; /* Number of ops in progress */
atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */
@@ -197,6 +200,7 @@ struct netfs_io_request {
size_t len; /* Length of the request */
short error; /* 0 or error that occurred */
enum netfs_io_origin origin; /* Origin of the request */
+ bool direct_bv_unpin; /* T if direct_bv[] must be unpinned */
loff_t i_size; /* Size of the file */
loff_t start; /* Start position */
pgoff_t no_unlock_folio; /* Don't unlock this folio after read */
Provide tools to create a buffer in an xarray, with a function to add new
folios with a mark. This will be used to create bounce buffer and can be
used more easily to create a list of folios the span of which would require
more than a page's worth of bio_vec structs.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/internal.h | 13 +++++++
fs/netfs/misc.c | 81 +++++++++++++++++++++++++++++++++++++++++++
include/linux/netfs.h | 4 +++
3 files changed, 98 insertions(+)
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 4708fb15446b..b908c7e0a901 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -56,6 +56,19 @@ static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) {}
static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {}
#endif
+/*
+ * misc.c
+ */
+#define NETFS_FLAG_PUT_MARK BIT(0)
+#define NETFS_FLAG_PAGECACHE_MARK BIT(1)
+int netfs_xa_store_and_mark(struct xarray *xa, unsigned long index,
+ struct folio *folio, unsigned int flags,
+ gfp_t gfp_mask);
+int netfs_add_folios_to_buffer(struct xarray *buffer,
+ struct address_space *mapping,
+ pgoff_t index, pgoff_t to, gfp_t gfp_mask);
+void netfs_clear_buffer(struct xarray *buffer);
+
/*
* objects.c
*/
diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c
index 45bb19ec9a63..5d545073fe03 100644
--- a/fs/netfs/misc.c
+++ b/fs/netfs/misc.c
@@ -8,6 +8,87 @@
#include <linux/swap.h>
#include "internal.h"
+/*
+ * Attach a folio to the buffer and maybe set marks on it to say that we need
+ * to put the folio later and twiddle the pagecache flags.
+ */
+int netfs_xa_store_and_mark(struct xarray *xa, unsigned long index,
+ struct folio *folio, unsigned int flags,
+ gfp_t gfp_mask)
+{
+ XA_STATE_ORDER(xas, xa, index, folio_order(folio));
+
+retry:
+ xas_lock(&xas);
+ for (;;) {
+ xas_store(&xas, folio);
+ if (!xas_error(&xas))
+ break;
+ xas_unlock(&xas);
+ if (!xas_nomem(&xas, gfp_mask))
+ return xas_error(&xas);
+ goto retry;
+ }
+
+ if (flags & NETFS_FLAG_PUT_MARK)
+ xas_set_mark(&xas, NETFS_BUF_PUT_MARK);
+ if (flags & NETFS_FLAG_PAGECACHE_MARK)
+ xas_set_mark(&xas, NETFS_BUF_PAGECACHE_MARK);
+ xas_unlock(&xas);
+ return xas_error(&xas);
+}
+
+/*
+ * Create the specified range of folios in the buffer attached to the read
+ * request. The folios are marked with NETFS_BUF_PUT_MARK so that we know that
+ * these need freeing later.
+ */
+int netfs_add_folios_to_buffer(struct xarray *buffer,
+ struct address_space *mapping,
+ pgoff_t index, pgoff_t to, gfp_t gfp_mask)
+{
+ struct folio *folio;
+ int ret;
+
+ if (to + 1 == index) /* Page range is inclusive */
+ return 0;
+
+ do {
+ /* TODO: Figure out what order folio can be allocated here */
+ folio = filemap_alloc_folio(readahead_gfp_mask(mapping), 0);
+ if (!folio)
+ return -ENOMEM;
+ folio->index = index;
+ ret = netfs_xa_store_and_mark(buffer, index, folio,
+ NETFS_FLAG_PUT_MARK, gfp_mask);
+ if (ret < 0) {
+ folio_put(folio);
+ return ret;
+ }
+
+ index += folio_nr_pages(folio);
+ } while (index <= to && index != 0);
+
+ return 0;
+}
+
+/*
+ * Clear an xarray buffer, putting a ref on the folios that have
+ * NETFS_BUF_PUT_MARK set.
+ */
+void netfs_clear_buffer(struct xarray *buffer)
+{
+ struct folio *folio;
+ XA_STATE(xas, buffer, 0);
+
+ rcu_read_lock();
+ xas_for_each_marked(&xas, folio, ULONG_MAX, NETFS_BUF_PUT_MARK) {
+ folio_put(folio);
+ }
+ rcu_read_unlock();
+ xa_destroy(buffer);
+}
+
/**
* netfs_dirty_folio - Mark folio dirty and pin a cache object for writeback
* @mapping: The mapping the folio belongs to.
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index bbb33ccbf719..c05150f51beb 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -109,6 +109,10 @@ static inline int wait_on_page_fscache_killable(struct page *page)
return folio_wait_private_2_killable(page_folio(page));
}
+/* Marks used on xarray-based buffers */
+#define NETFS_BUF_PUT_MARK XA_MARK_0 /* - Page needs putting */
+#define NETFS_BUF_PAGECACHE_MARK XA_MARK_1 /* - Page needs wb/dirty flag wrangling */
+
enum netfs_io_source {
NETFS_FILL_WITH_ZEROES,
NETFS_DOWNLOAD_FROM_SERVER,
Modify the netfs_io_request struct to act as a point around which writes
can be coordinated. It represents and pins a range of pages that need
writing and a list of regions of dirty data in that range of pages.
If RMW is required, the original data can be downloaded into the bounce
buffer, decrypted if necessary, the modifications made, then the modified
data can be reencrypted/recompressed and sent back to the server.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/internal.h | 6 ++++++
fs/netfs/main.c | 3 ++-
fs/netfs/objects.c | 6 ++++++
fs/netfs/stats.c | 16 +++++++++++++---
include/linux/netfs.h | 15 ++++++++++++++-
include/trace/events/netfs.h | 8 ++++++--
6 files changed, 47 insertions(+), 7 deletions(-)
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index b908c7e0a901..2bf2e82b2ad7 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -110,6 +110,12 @@ extern atomic_t netfs_n_rh_write_begin;
extern atomic_t netfs_n_rh_write_done;
extern atomic_t netfs_n_rh_write_failed;
extern atomic_t netfs_n_rh_write_zskip;
+extern atomic_t netfs_n_wh_upload;
+extern atomic_t netfs_n_wh_upload_done;
+extern atomic_t netfs_n_wh_upload_failed;
+extern atomic_t netfs_n_wh_write;
+extern atomic_t netfs_n_wh_write_done;
+extern atomic_t netfs_n_wh_write_failed;
int netfs_stats_show(struct seq_file *m, void *v);
diff --git a/fs/netfs/main.c b/fs/netfs/main.c
index 97ce1436615b..ab6cac110676 100644
--- a/fs/netfs/main.c
+++ b/fs/netfs/main.c
@@ -25,10 +25,11 @@ MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask");
LIST_HEAD(netfs_io_requests);
DEFINE_SPINLOCK(netfs_proc_lock);
-static const char *netfs_origins[] = {
+static const char *netfs_origins[nr__netfs_io_origin] = {
[NETFS_READAHEAD] = "RA",
[NETFS_READPAGE] = "RP",
[NETFS_READ_FOR_WRITE] = "RW",
+ [NETFS_WRITEBACK] = "WB",
};
/*
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index 4df5e5eeada6..65a17dd4ab49 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -20,6 +20,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
struct inode *inode = file ? file_inode(file) : mapping->host;
struct netfs_inode *ctx = netfs_inode(inode);
struct netfs_io_request *rreq;
+ bool cached = netfs_is_cache_enabled(ctx);
int ret;
rreq = kzalloc(ctx->ops->io_request_size ?: sizeof(struct netfs_io_request),
@@ -37,7 +38,10 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
rreq->debug_id = atomic_inc_return(&debug_ids);
INIT_LIST_HEAD(&rreq->subrequests);
refcount_set(&rreq->ref, 1);
+
__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
+ if (cached)
+ __set_bit(NETFS_RREQ_WRITE_TO_CACHE, &rreq->flags);
if (rreq->netfs_ops->init_request) {
ret = rreq->netfs_ops->init_request(rreq, file);
if (ret < 0) {
@@ -46,6 +50,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
}
}
+ trace_netfs_rreq_ref(rreq->debug_id, 1, netfs_rreq_trace_new);
netfs_proc_add_rreq(rreq);
netfs_stat(&netfs_n_rh_rreq);
return rreq;
@@ -129,6 +134,7 @@ struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq
sizeof(struct netfs_io_subrequest),
GFP_KERNEL);
if (subreq) {
+ INIT_WORK(&subreq->work, NULL);
INIT_LIST_HEAD(&subreq->rreq_link);
refcount_set(&subreq->ref, 2);
subreq->rreq = rreq;
diff --git a/fs/netfs/stats.c b/fs/netfs/stats.c
index 6025dc485f7e..c1f85cd595a4 100644
--- a/fs/netfs/stats.c
+++ b/fs/netfs/stats.c
@@ -27,6 +27,12 @@ atomic_t netfs_n_rh_write_begin;
atomic_t netfs_n_rh_write_done;
atomic_t netfs_n_rh_write_failed;
atomic_t netfs_n_rh_write_zskip;
+atomic_t netfs_n_wh_upload;
+atomic_t netfs_n_wh_upload_done;
+atomic_t netfs_n_wh_upload_failed;
+atomic_t netfs_n_wh_write;
+atomic_t netfs_n_wh_write_done;
+atomic_t netfs_n_wh_write_failed;
int netfs_stats_show(struct seq_file *m, void *v)
{
@@ -50,10 +56,14 @@ int netfs_stats_show(struct seq_file *m, void *v)
atomic_read(&netfs_n_rh_read),
atomic_read(&netfs_n_rh_read_done),
atomic_read(&netfs_n_rh_read_failed));
+ seq_printf(m, "Netfs : UL=%u us=%u uf=%u\n",
+ atomic_read(&netfs_n_wh_upload),
+ atomic_read(&netfs_n_wh_upload_done),
+ atomic_read(&netfs_n_wh_upload_failed));
seq_printf(m, "Netfs : WR=%u ws=%u wf=%u\n",
- atomic_read(&netfs_n_rh_write),
- atomic_read(&netfs_n_rh_write_done),
- atomic_read(&netfs_n_rh_write_failed));
+ atomic_read(&netfs_n_wh_write),
+ atomic_read(&netfs_n_wh_write_done),
+ atomic_read(&netfs_n_wh_write_failed));
return fscache_stats_show(m);
}
EXPORT_SYMBOL(netfs_stats_show);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 2ece21fccb02..d08bd37bc3ce 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -118,6 +118,9 @@ enum netfs_io_source {
NETFS_DOWNLOAD_FROM_SERVER,
NETFS_READ_FROM_CACHE,
NETFS_INVALID_READ,
+ NETFS_UPLOAD_TO_SERVER,
+ NETFS_WRITE_TO_CACHE,
+ NETFS_INVALID_WRITE,
} __mode(byte);
typedef void (*netfs_io_terminated_t)(void *priv, ssize_t transferred_or_error,
@@ -149,9 +152,14 @@ struct netfs_cache_resources {
};
/*
- * Descriptor for a single component subrequest.
+ * Descriptor for a single component subrequest. Each operation represents an
+ * individual read/write from/to a server, a cache, a journal, etc..
+ *
+ * The buffer iterator is persistent for the life of the subrequest struct and
+ * the pages it points to can be relied on to exist for the duration.
*/
struct netfs_io_subrequest {
+ struct work_struct work;
struct netfs_io_request *rreq; /* Supervising I/O request */
struct list_head rreq_link; /* Link in rreq->subrequests */
struct iov_iter io_iter; /* Iterator for this subrequest */
@@ -176,6 +184,8 @@ enum netfs_io_origin {
NETFS_READAHEAD, /* This read was triggered by readahead */
NETFS_READPAGE, /* This read is a synchronous read */
NETFS_READ_FOR_WRITE, /* This read is to prepare a write */
+ NETFS_WRITEBACK, /* This write was triggered by writepages */
+ nr__netfs_io_origin
} __mode(byte);
/*
@@ -199,6 +209,7 @@ struct netfs_io_request {
__counted_by(direct_bv_count);
unsigned int direct_bv_count; /* Number of elements in direct_bv[] */
unsigned int debug_id;
+ unsigned int subreq_counter; /* Next subreq->debug_index */
atomic_t nr_outstanding; /* Number of ops in progress */
atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */
size_t submitted; /* Amount submitted for I/O so far */
@@ -217,6 +228,8 @@ struct netfs_io_request {
#define NETFS_RREQ_DONT_UNLOCK_FOLIOS 3 /* Don't unlock the folios on completion */
#define NETFS_RREQ_FAILED 4 /* The request failed */
#define NETFS_RREQ_IN_PROGRESS 5 /* Unlocked when the request completes */
+#define NETFS_RREQ_WRITE_TO_CACHE 7 /* Need to write to the cache */
+#define NETFS_RREQ_UPLOAD_TO_SERVER 8 /* Need to write to the server */
const struct netfs_request_ops *netfs_ops;
};
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index fce6d0bc78e5..4ea4e34d279f 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -24,7 +24,8 @@
#define netfs_rreq_origins \
EM(NETFS_READAHEAD, "RA") \
EM(NETFS_READPAGE, "RP") \
- E_(NETFS_READ_FOR_WRITE, "RW")
+ EM(NETFS_READ_FOR_WRITE, "RW") \
+ E_(NETFS_WRITEBACK, "WB")
#define netfs_rreq_traces \
EM(netfs_rreq_trace_assess, "ASSESS ") \
@@ -39,7 +40,10 @@
EM(NETFS_FILL_WITH_ZEROES, "ZERO") \
EM(NETFS_DOWNLOAD_FROM_SERVER, "DOWN") \
EM(NETFS_READ_FROM_CACHE, "READ") \
- E_(NETFS_INVALID_READ, "INVL") \
+ EM(NETFS_INVALID_READ, "INVL") \
+ EM(NETFS_UPLOAD_TO_SERVER, "UPLD") \
+ EM(NETFS_WRITE_TO_CACHE, "WRIT") \
+ E_(NETFS_INVALID_WRITE, "INVL")
#define netfs_sreq_traces \
EM(netfs_sreq_trace_download_instead, "RDOWN") \
Make netfs_put_request() just return if given a NULL request pointer.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/objects.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index 65a17dd4ab49..3aa0bfbc04ec 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -106,19 +106,22 @@ static void netfs_free_request(struct work_struct *work)
void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
enum netfs_rreq_ref_trace what)
{
- unsigned int debug_id = rreq->debug_id;
+ unsigned int debug_id;
bool dead;
int r;
- dead = __refcount_dec_and_test(&rreq->ref, &r);
- trace_netfs_rreq_ref(debug_id, r - 1, what);
- if (dead) {
- if (was_async) {
- rreq->work.func = netfs_free_request;
- if (!queue_work(system_unbound_wq, &rreq->work))
- BUG();
- } else {
- netfs_free_request(&rreq->work);
+ if (rreq) {
+ debug_id = rreq->debug_id;
+ dead = __refcount_dec_and_test(&rreq->ref, &r);
+ trace_netfs_rreq_ref(debug_id, r - 1, what);
+ if (dead) {
+ if (was_async) {
+ rreq->work.func = netfs_free_request;
+ if (!queue_work(system_unbound_wq, &rreq->work))
+ BUG();
+ } else {
+ netfs_free_request(&rreq->work);
+ }
}
}
}
Make the refcounting of netfs_begin_read() easier to use by not eating the
caller's ref on the netfs_io_request it's given. This makes it easier to
use when we need to look in the request struct after.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/buffered_read.c | 6 +++++-
fs/netfs/io.c | 28 +++++++++++++---------------
include/trace/events/netfs.h | 9 +++++----
3 files changed, 23 insertions(+), 20 deletions(-)
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 751556faa70b..6b9a44cafbac 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -210,6 +210,7 @@ void netfs_readahead(struct readahead_control *ractl)
;
netfs_begin_read(rreq, false);
+ netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
return;
cleanup_free:
@@ -260,7 +261,9 @@ int netfs_read_folio(struct file *file, struct folio *folio)
iov_iter_xarray(&rreq->iter, ITER_DEST, &mapping->i_pages,
rreq->start, rreq->len);
- return netfs_begin_read(rreq, true);
+ ret = netfs_begin_read(rreq, true);
+ netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
+ return ret;
discard:
netfs_put_request(rreq, false, netfs_rreq_trace_put_discard);
@@ -429,6 +432,7 @@ int netfs_write_begin(struct netfs_inode *ctx,
ret = netfs_begin_read(rreq, true);
if (ret < 0)
goto error;
+ netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
have_folio:
ret = folio_wait_fscache_killable(folio);
diff --git a/fs/netfs/io.c b/fs/netfs/io.c
index e228bfb530ea..e83ef5835d25 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -362,6 +362,7 @@ static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
netfs_rreq_unlock_folios(rreq);
+ trace_netfs_rreq(rreq, netfs_rreq_trace_wake_ip);
clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
wake_up_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS);
@@ -657,7 +658,6 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
if (rreq->len == 0) {
pr_err("Zero-sized read [R=%x]\n", rreq->debug_id);
- netfs_put_request(rreq, false, netfs_rreq_trace_put_zero_len);
return -EIO;
}
@@ -665,12 +665,10 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
INIT_WORK(&rreq->work, netfs_rreq_work);
- if (sync)
- netfs_get_request(rreq, netfs_rreq_trace_get_hold);
-
/* Chop the read into slices according to what the cache and the netfs
* want and submit each one.
*/
+ netfs_get_request(rreq, netfs_rreq_trace_get_for_outstanding);
atomic_set(&rreq->nr_outstanding, 1);
io_iter = rreq->io_iter;
do {
@@ -680,25 +678,25 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
} while (rreq->submitted < rreq->len);
if (sync) {
- /* Keep nr_outstanding incremented so that the ref always belongs to
- * us, and the service code isn't punted off to a random thread pool to
- * process.
+ /* Keep nr_outstanding incremented so that the ref always
+ * belongs to us, and the service code isn't punted off to a
+ * random thread pool to process. Note that this might start
+ * further work, such as writing to the cache.
*/
- for (;;) {
- wait_var_event(&rreq->nr_outstanding,
- atomic_read(&rreq->nr_outstanding) == 1);
+ wait_var_event(&rreq->nr_outstanding,
+ atomic_read(&rreq->nr_outstanding) == 1);
+ if (atomic_dec_and_test(&rreq->nr_outstanding))
netfs_rreq_assess(rreq, false);
- if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags))
- break;
- cond_resched();
- }
+
+ trace_netfs_rreq(rreq, netfs_rreq_trace_wait_ip);
+ wait_on_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS,
+ TASK_UNINTERRUPTIBLE);
ret = rreq->error;
if (ret == 0 && rreq->submitted < rreq->len) {
trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read);
ret = -EIO;
}
- netfs_put_request(rreq, false, netfs_rreq_trace_put_hold);
} else {
/* If we decrement nr_outstanding to 0, the ref belongs to us. */
if (atomic_dec_and_test(&rreq->nr_outstanding))
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 4ea4e34d279f..6daadf2aac8a 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -34,7 +34,9 @@
EM(netfs_rreq_trace_free, "FREE ") \
EM(netfs_rreq_trace_resubmit, "RESUBMT") \
EM(netfs_rreq_trace_unlock, "UNLOCK ") \
- E_(netfs_rreq_trace_unmark, "UNMARK ")
+ EM(netfs_rreq_trace_unmark, "UNMARK ") \
+ EM(netfs_rreq_trace_wait_ip, "WAIT-IP") \
+ E_(netfs_rreq_trace_wake_ip, "WAKE-IP")
#define netfs_sreq_sources \
EM(NETFS_FILL_WITH_ZEROES, "ZERO") \
@@ -65,14 +67,13 @@
E_(netfs_fail_prepare_write, "prep-write")
#define netfs_rreq_ref_traces \
- EM(netfs_rreq_trace_get_hold, "GET HOLD ") \
+ EM(netfs_rreq_trace_get_for_outstanding,"GET OUTSTND") \
EM(netfs_rreq_trace_get_subreq, "GET SUBREQ ") \
EM(netfs_rreq_trace_put_complete, "PUT COMPLT ") \
EM(netfs_rreq_trace_put_discard, "PUT DISCARD") \
EM(netfs_rreq_trace_put_failed, "PUT FAILED ") \
- EM(netfs_rreq_trace_put_hold, "PUT HOLD ") \
+ EM(netfs_rreq_trace_put_return, "PUT RETURN ") \
EM(netfs_rreq_trace_put_subreq, "PUT SUBREQ ") \
- EM(netfs_rreq_trace_put_zero_len, "PUT ZEROLEN") \
E_(netfs_rreq_trace_new, "NEW ")
#define netfs_sreq_ref_traces \
Prepare to use folio->private to hold information write grouping and
streaming write. These are implemented in the same commit as they both
make use of folio->private and will be both checked at the same time in
several places.
"Write grouping" involves ordering the writeback of groups of writes, such
as is needed for ceph snaps. A group is represented by a
filesystem-supplied object which must contain a netfs_group struct. This
contains just a refcount and a pointer to a destructor.
"Streaming write" is the storage of data in folios that are marked dirty,
but not uptodate, to avoid unnecessary reads of data. This is represented
by a netfs_folio struct. This contains the offset and length of the
modified region plus the otherwise displaced write grouping pointer.
The way folio->private is multiplexed is:
(1) If private is NULL then neither is in operation on a dirty folio.
(2) If private is set, with bit 0 clear, then this points to a group.
(3) If private is set, with bit 0 set, then this points to a netfs_folio
struct (with bit 0 AND'ed out).
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/internal.h | 28 ++++++++++++++++++++++++++
fs/netfs/misc.c | 46 +++++++++++++++++++++++++++++++++++++++++++
include/linux/netfs.h | 41 ++++++++++++++++++++++++++++++++++++++
3 files changed, 115 insertions(+)
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 2bf2e82b2ad7..d72292e40f9b 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -149,6 +149,34 @@ static inline bool netfs_is_cache_enabled(struct netfs_inode *ctx)
#endif
}
+/*
+ * Get a ref on a netfs group attached to a dirty page (e.g. a ceph snap).
+ */
+static inline struct netfs_group *netfs_get_group(struct netfs_group *netfs_group)
+{
+ if (netfs_group)
+ refcount_inc(&netfs_group->ref);
+ return netfs_group;
+}
+
+/*
+ * Dispose of a netfs group attached to a dirty page (e.g. a ceph snap).
+ */
+static inline void netfs_put_group(struct netfs_group *netfs_group)
+{
+ if (netfs_group && refcount_dec_and_test(&netfs_group->ref))
+ netfs_group->free(netfs_group);
+}
+
+/*
+ * Dispose of a netfs group attached to a dirty page (e.g. a ceph snap).
+ */
+static inline void netfs_put_group_many(struct netfs_group *netfs_group, int nr)
+{
+ if (netfs_group && refcount_sub_and_test(nr, &netfs_group->ref))
+ netfs_group->free(netfs_group);
+}
+
/*
* fscache-cache.c
*/
diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c
index 5d545073fe03..eeb44abe59c5 100644
--- a/fs/netfs/misc.c
+++ b/fs/netfs/misc.c
@@ -177,9 +177,55 @@ EXPORT_SYMBOL(netfs_clear_inode_writeback);
*/
void netfs_invalidate_folio(struct folio *folio, size_t offset, size_t length)
{
+ struct netfs_folio *finfo = NULL;
+ size_t flen = folio_size(folio);
+
_enter("{%lx},%zx,%zx", folio_index(folio), offset, length);
folio_wait_fscache(folio);
+
+ if (!folio_test_private(folio))
+ return;
+
+ finfo = netfs_folio_info(folio);
+
+ if (offset == 0 && length >= flen)
+ goto erase_completely;
+
+ if (finfo) {
+ /* We have a partially uptodate page from a streaming write. */
+ unsigned int fstart = finfo->dirty_offset;
+ unsigned int fend = fstart + finfo->dirty_len;
+ unsigned int end = offset + length;
+
+ if (offset >= fend)
+ return;
+ if (end <= fstart)
+ return;
+ if (offset <= fstart && end >= fend)
+ goto erase_completely;
+ if (offset <= fstart && end > fstart)
+ goto reduce_len;
+ if (offset > fstart && end >= fend)
+ goto move_start;
+ /* A partial write was split. The caller has already zeroed
+ * it, so just absorb the hole.
+ */
+ }
+ return;
+
+erase_completely:
+ netfs_put_group(netfs_folio_group(folio));
+ folio_detach_private(folio);
+ folio_clear_uptodate(folio);
+ kfree(finfo);
+ return;
+reduce_len:
+ finfo->dirty_len = offset + length - finfo->dirty_offset;
+ return;
+move_start:
+ finfo->dirty_len -= offset - finfo->dirty_offset;
+ finfo->dirty_offset = offset;
}
EXPORT_SYMBOL(netfs_invalidate_folio);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index f87193fa0f16..bb78021332f5 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -140,6 +140,47 @@ struct netfs_inode {
#define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */
};
+/*
+ * A netfs group - for instance a ceph snap. This is marked on dirty pages and
+ * pages marked with a group must be flushed before they can be written under
+ * the domain of another group.
+ */
+struct netfs_group {
+ refcount_t ref;
+ void (*free)(struct netfs_group *netfs_group);
+};
+
+/*
+ * Information about a dirty page (attached only if necessary).
+ * folio->private
+ */
+struct netfs_folio {
+ struct netfs_group *netfs_group; /* Filesystem's grouping marker (or NULL). */
+ unsigned int dirty_offset; /* Write-streaming dirty data offset */
+ unsigned int dirty_len; /* Write-streaming dirty data length */
+};
+#define NETFS_FOLIO_INFO 0x1UL /* OR'd with folio->private. */
+
+static inline struct netfs_folio *netfs_folio_info(struct folio *folio)
+{
+ void *priv = folio_get_private(folio);
+
+ if ((unsigned long)priv & NETFS_FOLIO_INFO)
+ return (struct netfs_folio *)((unsigned long)priv & ~NETFS_FOLIO_INFO);
+ return NULL;
+}
+
+static inline struct netfs_group *netfs_folio_group(struct folio *folio)
+{
+ struct netfs_folio *finfo;
+ void *priv = folio_get_private(folio);
+
+ finfo = netfs_folio_info(folio);
+ if (finfo)
+ return finfo->netfs_group;
+ return priv;
+}
+
/*
* Resources required to do operations on a cache.
*/
Add a hook for netfslib's write helpers to call to tell the network
filesystem that it should update its i_size.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
include/linux/netfs.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index d08bd37bc3ce..f87193fa0f16 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -243,6 +243,7 @@ struct netfs_request_ops {
void (*free_request)(struct netfs_io_request *rreq);
void (*free_subrequest)(struct netfs_io_subrequest *rreq);
+ /* Read request handling */
void (*expand_readahead)(struct netfs_io_request *rreq);
bool (*clamp_length)(struct netfs_io_subrequest *subreq);
void (*issue_read)(struct netfs_io_subrequest *subreq);
@@ -250,6 +251,9 @@ struct netfs_request_ops {
int (*check_write_begin)(struct file *file, loff_t pos, unsigned len,
struct folio **foliop, void **_fsdata);
void (*done)(struct netfs_io_request *rreq);
+
+ /* Modification handling */
+ void (*update_i_size)(struct inode *inode, loff_t i_size);
};
/*
Dispatch one or more write reqeusts to process a writeback slice, where a
slice is tailored more to logical block divisions within the file (such as
crypto blocks, an object layout or cache granules) than the protocol RPC
maximum capacity.
The dispatch doesn't happen until throttling allows, at which point the
entire writeback slice is processed and queued. A slice may be written to
multiple destinations (one or more servers and the local cache) and the
writes to each destination might be split up along different lines.
The writeback slice holds the required folios pinned. An iov_iter is
provided in netfs_write_request that describes the buffer to be used. This
may be part of the pagecache, may have auxiliary padding pages attached or
may be a bounce buffer resulting from crypto or compression. Consequently,
the filesystem must not twiddle the folio markings directly.
The following API is available to the filesystem:
(1) The ->create_write_requests() method is called to ask the filesystem
to create the requests it needs. This is passed the writeback slice
to be processed.
(2) The filesystem should then call netfs_create_write_request() to create
the requests it needs.
(3) Once a request is initialised, netfs_queue_write_request() can be
called to dispatch it asynchronously, if not completed immediately.
(4) netfs_write_request_completed() should be called to note the
completion of a request.
(5) netfs_get_write_request() and netfs_put_write_request() are provided
to refcount a request. These take constants from the netfs_wreq_trace
enum for logging into ftrace.
(6) The ->free_write_request is method is called to ask the filesystem to
clean up a request.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/Makefile | 3 +-
fs/netfs/internal.h | 6 +
fs/netfs/output.c | 363 +++++++++++++++++++++++++++++++++++
include/linux/netfs.h | 13 ++
include/trace/events/netfs.h | 50 ++++-
5 files changed, 432 insertions(+), 3 deletions(-)
create mode 100644 fs/netfs/output.c
diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
index cf3fc847b8ac..c69c6775b8ac 100644
--- a/fs/netfs/Makefile
+++ b/fs/netfs/Makefile
@@ -7,7 +7,8 @@ netfs-y := \
locking.o \
main.o \
misc.o \
- objects.o
+ objects.o \
+ output.o
netfs-$(CONFIG_NETFS_STATS) += stats.o
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index d72292e40f9b..0f20587f5a9b 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -88,6 +88,12 @@ static inline void netfs_see_request(struct netfs_io_request *rreq,
trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), what);
}
+/*
+ * output.c
+ */
+int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
+ enum netfs_write_trace what);
+
/*
* stats.c
*/
diff --git a/fs/netfs/output.c b/fs/netfs/output.c
new file mode 100644
index 000000000000..2ad0fd8c32be
--- /dev/null
+++ b/fs/netfs/output.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Network filesystem high-level write support.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells ([email protected])
+ */
+
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/writeback.h>
+#include <linux/pagevec.h>
+#include "internal.h"
+
+/**
+ * netfs_create_write_request - Create a write operation.
+ * @wreq: The write request this is storing from.
+ * @dest: The destination type
+ * @start: Start of the region this write will modify
+ * @len: Length of the modification
+ * @worker: The worker function to handle the write(s)
+ *
+ * Allocate a write operation, set it up and add it to the list on a write
+ * request.
+ */
+struct netfs_io_subrequest *netfs_create_write_request(struct netfs_io_request *wreq,
+ enum netfs_io_source dest,
+ loff_t start, size_t len,
+ work_func_t worker)
+{
+ struct netfs_io_subrequest *subreq;
+
+ subreq = netfs_alloc_subrequest(wreq);
+ if (subreq) {
+ INIT_WORK(&subreq->work, worker);
+ subreq->source = dest;
+ subreq->start = start;
+ subreq->len = len;
+ subreq->debug_index = wreq->subreq_counter++;
+
+ switch (subreq->source) {
+ case NETFS_UPLOAD_TO_SERVER:
+ netfs_stat(&netfs_n_wh_upload);
+ break;
+ case NETFS_WRITE_TO_CACHE:
+ netfs_stat(&netfs_n_wh_write);
+ break;
+ default:
+ BUG();
+ }
+
+ subreq->io_iter = wreq->io_iter;
+ iov_iter_advance(&subreq->io_iter, subreq->start - wreq->start);
+ iov_iter_truncate(&subreq->io_iter, subreq->len);
+
+ trace_netfs_sreq_ref(wreq->debug_id, subreq->debug_index,
+ refcount_read(&subreq->ref),
+ netfs_sreq_trace_new);
+ atomic_inc(&wreq->nr_outstanding);
+ list_add_tail(&subreq->rreq_link, &wreq->subrequests);
+ trace_netfs_sreq(subreq, netfs_sreq_trace_prepare);
+ }
+
+ return subreq;
+}
+EXPORT_SYMBOL(netfs_create_write_request);
+
+/*
+ * Process a completed write request once all the component operations have
+ * been completed.
+ */
+static void netfs_write_terminated(struct netfs_io_request *wreq, bool was_async)
+{
+ struct netfs_io_subrequest *subreq;
+ struct netfs_inode *ctx = netfs_inode(wreq->inode);
+
+ _enter("R=%x[]", wreq->debug_id);
+
+ trace_netfs_rreq(wreq, netfs_rreq_trace_write_done);
+
+ list_for_each_entry(subreq, &wreq->subrequests, rreq_link) {
+ if (!subreq->error)
+ continue;
+ switch (subreq->source) {
+ case NETFS_UPLOAD_TO_SERVER:
+ /* Depending on the type of failure, this may prevent
+ * writeback completion unless we're in disconnected
+ * mode.
+ */
+ if (!wreq->error)
+ wreq->error = subreq->error;
+ break;
+
+ case NETFS_WRITE_TO_CACHE:
+ /* Failure doesn't prevent writeback completion unless
+ * we're in disconnected mode.
+ */
+ if (subreq->error != -ENOBUFS)
+ ctx->ops->invalidate_cache(wreq);
+ break;
+
+ default:
+ WARN_ON_ONCE(1);
+ if (!wreq->error)
+ wreq->error = -EIO;
+ return;
+ }
+ }
+
+ wreq->cleanup(wreq);
+
+ _debug("finished");
+ trace_netfs_rreq(wreq, netfs_rreq_trace_wake_ip);
+ clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &wreq->flags);
+ wake_up_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS);
+
+ netfs_clear_subrequests(wreq, was_async);
+ netfs_put_request(wreq, was_async, netfs_rreq_trace_put_complete);
+}
+
+/*
+ * Deal with the completion of writing the data to the cache.
+ */
+void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error,
+ bool was_async)
+{
+ struct netfs_io_subrequest *subreq = _op;
+ struct netfs_io_request *wreq = subreq->rreq;
+ unsigned int u;
+
+ _enter("%x[%x] %zd", wreq->debug_id, subreq->debug_index, transferred_or_error);
+
+ switch (subreq->source) {
+ case NETFS_UPLOAD_TO_SERVER:
+ netfs_stat(&netfs_n_wh_upload_done);
+ break;
+ case NETFS_WRITE_TO_CACHE:
+ netfs_stat(&netfs_n_wh_write_done);
+ break;
+ case NETFS_INVALID_WRITE:
+ break;
+ default:
+ BUG();
+ }
+
+ if (IS_ERR_VALUE(transferred_or_error)) {
+ subreq->error = transferred_or_error;
+ trace_netfs_failure(wreq, subreq, transferred_or_error,
+ netfs_fail_write);
+ goto failed;
+ }
+
+ if (WARN(transferred_or_error > subreq->len - subreq->transferred,
+ "Subreq excess write: R%x[%x] %zd > %zu - %zu",
+ wreq->debug_id, subreq->debug_index,
+ transferred_or_error, subreq->len, subreq->transferred))
+ transferred_or_error = subreq->len - subreq->transferred;
+
+ subreq->error = 0;
+ subreq->transferred += transferred_or_error;
+
+ if (iov_iter_count(&subreq->io_iter) != subreq->len - subreq->transferred)
+ pr_warn("R=%08x[%u] ITER POST-MISMATCH %zx != %zx-%zx %x\n",
+ wreq->debug_id, subreq->debug_index,
+ iov_iter_count(&subreq->io_iter), subreq->len,
+ subreq->transferred, subreq->io_iter.iter_type);
+
+ if (subreq->transferred < subreq->len)
+ goto incomplete;
+
+ __clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
+out:
+ trace_netfs_sreq(subreq, netfs_sreq_trace_terminated);
+
+ /* If we decrement nr_outstanding to 0, the ref belongs to us. */
+ u = atomic_dec_return(&wreq->nr_outstanding);
+ if (u == 0)
+ netfs_write_terminated(wreq, was_async);
+ else if (u == 1)
+ wake_up_var(&wreq->nr_outstanding);
+
+ netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
+ return;
+
+incomplete:
+ if (transferred_or_error == 0) {
+ if (__test_and_set_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags)) {
+ subreq->error = -ENODATA;
+ goto failed;
+ }
+ } else {
+ __clear_bit(NETFS_SREQ_NO_PROGRESS, &subreq->flags);
+ }
+
+ __set_bit(NETFS_SREQ_SHORT_IO, &subreq->flags);
+ set_bit(NETFS_RREQ_INCOMPLETE_IO, &wreq->flags);
+ goto out;
+
+failed:
+ switch (subreq->source) {
+ case NETFS_WRITE_TO_CACHE:
+ netfs_stat(&netfs_n_wh_write_failed);
+ set_bit(NETFS_RREQ_INCOMPLETE_IO, &wreq->flags);
+ break;
+ case NETFS_UPLOAD_TO_SERVER:
+ netfs_stat(&netfs_n_wh_upload_failed);
+ set_bit(NETFS_RREQ_FAILED, &wreq->flags);
+ wreq->error = subreq->error;
+ break;
+ default:
+ break;
+ }
+ goto out;
+}
+EXPORT_SYMBOL(netfs_write_subrequest_terminated);
+
+static void netfs_write_to_cache_op(struct netfs_io_subrequest *subreq)
+{
+ struct netfs_io_request *wreq = subreq->rreq;
+ struct netfs_cache_resources *cres = &wreq->cache_resources;
+
+ trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
+
+ cres->ops->write(cres, subreq->start, &subreq->io_iter,
+ netfs_write_subrequest_terminated, subreq);
+}
+
+static void netfs_write_to_cache_op_worker(struct work_struct *work)
+{
+ struct netfs_io_subrequest *subreq =
+ container_of(work, struct netfs_io_subrequest, work);
+
+ netfs_write_to_cache_op(subreq);
+}
+
+/**
+ * netfs_queue_write_request - Queue a write request for attention
+ * @subreq: The write request to be queued
+ *
+ * Queue the specified write request for processing by a worker thread. We
+ * pass the caller's ref on the request to the worker thread.
+ */
+void netfs_queue_write_request(struct netfs_io_subrequest *subreq)
+{
+ if (!queue_work(system_unbound_wq, &subreq->work))
+ netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_wip);
+}
+EXPORT_SYMBOL(netfs_queue_write_request);
+
+/*
+ * Set up a op for writing to the cache.
+ */
+static void netfs_set_up_write_to_cache(struct netfs_io_request *wreq)
+{
+ struct netfs_cache_resources *cres;
+ struct netfs_io_subrequest *subreq;
+ struct netfs_inode *ctx = netfs_inode(wreq->inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(ctx);
+ loff_t start = wreq->start;
+ size_t len = wreq->len;
+ int ret;
+
+ if (!fscache_cookie_enabled(cookie)) {
+ clear_bit(NETFS_RREQ_WRITE_TO_CACHE, &wreq->flags);
+ return;
+ }
+
+ _debug("write to cache");
+ subreq = netfs_create_write_request(wreq, NETFS_WRITE_TO_CACHE, start, len,
+ netfs_write_to_cache_op_worker);
+ if (!subreq)
+ return;
+
+ cres = &wreq->cache_resources;
+ ret = fscache_begin_read_operation(cres, cookie);
+ if (ret < 0) {
+ netfs_write_subrequest_terminated(subreq, ret, false);
+ return;
+ }
+
+ ret = cres->ops->prepare_write(cres, &start, &len, i_size_read(wreq->inode),
+ true);
+ if (ret < 0) {
+ netfs_write_subrequest_terminated(subreq, ret, false);
+ return;
+ }
+
+ netfs_queue_write_request(subreq);
+}
+
+/*
+ * Begin the process of writing out a chunk of data.
+ *
+ * We are given a write request that holds a series of dirty regions and
+ * (partially) covers a sequence of folios, all of which are present. The
+ * pages must have been marked as writeback as appropriate.
+ *
+ * We need to perform the following steps:
+ *
+ * (1) If encrypting, create an output buffer and encrypt each block of the
+ * data into it, otherwise the output buffer will point to the original
+ * folios.
+ *
+ * (2) If the data is to be cached, set up a write op for the entire output
+ * buffer to the cache, if the cache wants to accept it.
+ *
+ * (3) If the data is to be uploaded (ie. not merely cached):
+ *
+ * (a) If the data is to be compressed, create a compression buffer and
+ * compress the data into it.
+ *
+ * (b) For each destination we want to upload to, set up write ops to write
+ * to that destination. We may need multiple writes if the data is not
+ * contiguous or the span exceeds wsize for a server.
+ */
+int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
+ enum netfs_write_trace what)
+{
+ struct netfs_inode *ctx = netfs_inode(wreq->inode);
+
+ _enter("R=%x %llx-%llx f=%lx",
+ wreq->debug_id, wreq->start, wreq->start + wreq->len - 1,
+ wreq->flags);
+
+ trace_netfs_write(wreq, what);
+ if (wreq->len == 0 || wreq->iter.count == 0) {
+ pr_err("Zero-sized write [R=%x]\n", wreq->debug_id);
+ return -EIO;
+ }
+
+ wreq->io_iter = wreq->iter;
+
+ /* ->outstanding > 0 carries a ref */
+ netfs_get_request(wreq, netfs_rreq_trace_get_for_outstanding);
+ atomic_set(&wreq->nr_outstanding, 1);
+
+ /* Start the encryption/compression going. We can do that in the
+ * background whilst we generate a list of write ops that we want to
+ * perform.
+ */
+ // TODO: Encrypt or compress the region as appropriate
+
+ /* We need to write all of the region to the cache */
+ if (test_bit(NETFS_RREQ_WRITE_TO_CACHE, &wreq->flags))
+ netfs_set_up_write_to_cache(wreq);
+
+ /* However, we don't necessarily write all of the region to the server.
+ * Caching of reads is being managed this way also.
+ */
+ if (test_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags))
+ ctx->ops->create_write_requests(wreq, wreq->start, wreq->len);
+
+ if (atomic_dec_and_test(&wreq->nr_outstanding))
+ netfs_write_terminated(wreq, false);
+
+ if (!may_wait)
+ return -EIOCBQUEUED;
+
+ wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,
+ TASK_UNINTERRUPTIBLE);
+ return wreq->error;
+}
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index bb78021332f5..78d9f9486ee4 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -250,6 +250,7 @@ struct netfs_io_request {
__counted_by(direct_bv_count);
unsigned int direct_bv_count; /* Number of elements in direct_bv[] */
unsigned int debug_id;
+ unsigned int wsize; /* Maximum write size (0 for none) */
unsigned int subreq_counter; /* Next subreq->debug_index */
atomic_t nr_outstanding; /* Number of ops in progress */
atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */
@@ -272,6 +273,7 @@ struct netfs_io_request {
#define NETFS_RREQ_WRITE_TO_CACHE 7 /* Need to write to the cache */
#define NETFS_RREQ_UPLOAD_TO_SERVER 8 /* Need to write to the server */
const struct netfs_request_ops *netfs_ops;
+ void (*cleanup)(struct netfs_io_request *req);
};
/*
@@ -295,6 +297,11 @@ struct netfs_request_ops {
/* Modification handling */
void (*update_i_size)(struct inode *inode, loff_t i_size);
+
+ /* Write request handling */
+ void (*create_write_requests)(struct netfs_io_request *wreq,
+ loff_t start, size_t len);
+ void (*invalidate_cache)(struct netfs_io_request *wreq);
};
/*
@@ -383,6 +390,12 @@ ssize_t netfs_extract_user_iter(struct iov_iter *orig, size_t orig_len,
iov_iter_extraction_t extraction_flags);
size_t netfs_limit_iter(const struct iov_iter *iter, size_t start_offset,
size_t max_size, size_t max_segs);
+struct netfs_io_subrequest *netfs_create_write_request(
+ struct netfs_io_request *wreq, enum netfs_io_source dest,
+ loff_t start, size_t len, work_func_t worker);
+void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error,
+ bool was_async);
+void netfs_queue_write_request(struct netfs_io_subrequest *subreq);
int netfs_start_io_read(struct inode *inode);
void netfs_end_io_read(struct inode *inode);
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 6daadf2aac8a..e03635172760 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -21,6 +21,11 @@
EM(netfs_read_trace_readpage, "READPAGE ") \
E_(netfs_read_trace_write_begin, "WRITEBEGN")
+#define netfs_write_traces \
+ EM(netfs_write_trace_dio_write, "DIO-WRITE") \
+ EM(netfs_write_trace_unbuffered_write, "UNB-WRITE") \
+ E_(netfs_write_trace_writeback, "WRITEBACK")
+
#define netfs_rreq_origins \
EM(NETFS_READAHEAD, "RA") \
EM(NETFS_READPAGE, "RP") \
@@ -32,11 +37,13 @@
EM(netfs_rreq_trace_copy, "COPY ") \
EM(netfs_rreq_trace_done, "DONE ") \
EM(netfs_rreq_trace_free, "FREE ") \
+ EM(netfs_rreq_trace_redirty, "REDIRTY") \
EM(netfs_rreq_trace_resubmit, "RESUBMT") \
EM(netfs_rreq_trace_unlock, "UNLOCK ") \
EM(netfs_rreq_trace_unmark, "UNMARK ") \
EM(netfs_rreq_trace_wait_ip, "WAIT-IP") \
- E_(netfs_rreq_trace_wake_ip, "WAKE-IP")
+ EM(netfs_rreq_trace_wake_ip, "WAKE-IP") \
+ E_(netfs_rreq_trace_write_done, "WR-DONE")
#define netfs_sreq_sources \
EM(NETFS_FILL_WITH_ZEROES, "ZERO") \
@@ -64,7 +71,8 @@
EM(netfs_fail_copy_to_cache, "copy-to-cache") \
EM(netfs_fail_read, "read") \
EM(netfs_fail_short_read, "short-read") \
- E_(netfs_fail_prepare_write, "prep-write")
+ EM(netfs_fail_prepare_write, "prep-write") \
+ E_(netfs_fail_write, "write")
#define netfs_rreq_ref_traces \
EM(netfs_rreq_trace_get_for_outstanding,"GET OUTSTND") \
@@ -74,6 +82,8 @@
EM(netfs_rreq_trace_put_failed, "PUT FAILED ") \
EM(netfs_rreq_trace_put_return, "PUT RETURN ") \
EM(netfs_rreq_trace_put_subreq, "PUT SUBREQ ") \
+ EM(netfs_rreq_trace_put_work, "PUT WORK ") \
+ EM(netfs_rreq_trace_see_work, "SEE WORK ") \
E_(netfs_rreq_trace_new, "NEW ")
#define netfs_sreq_ref_traces \
@@ -82,9 +92,12 @@
EM(netfs_sreq_trace_get_short_read, "GET SHORTRD") \
EM(netfs_sreq_trace_new, "NEW ") \
EM(netfs_sreq_trace_put_clear, "PUT CLEAR ") \
+ EM(netfs_sreq_trace_put_discard, "PUT DISCARD") \
EM(netfs_sreq_trace_put_failed, "PUT FAILED ") \
EM(netfs_sreq_trace_put_merged, "PUT MERGED ") \
EM(netfs_sreq_trace_put_no_copy, "PUT NO COPY") \
+ EM(netfs_sreq_trace_put_wip, "PUT WIP ") \
+ EM(netfs_sreq_trace_put_work, "PUT WORK ") \
E_(netfs_sreq_trace_put_terminated, "PUT TERM ")
#ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
@@ -96,6 +109,7 @@
#define E_(a, b) a
enum netfs_read_trace { netfs_read_traces } __mode(byte);
+enum netfs_write_trace { netfs_write_traces } __mode(byte);
enum netfs_rreq_trace { netfs_rreq_traces } __mode(byte);
enum netfs_sreq_trace { netfs_sreq_traces } __mode(byte);
enum netfs_failure { netfs_failures } __mode(byte);
@@ -113,6 +127,7 @@ enum netfs_sreq_ref_trace { netfs_sreq_ref_traces } __mode(byte);
#define E_(a, b) TRACE_DEFINE_ENUM(a);
netfs_read_traces;
+netfs_write_traces;
netfs_rreq_origins;
netfs_rreq_traces;
netfs_sreq_sources;
@@ -320,6 +335,37 @@ TRACE_EVENT(netfs_sreq_ref,
__entry->ref)
);
+TRACE_EVENT(netfs_write,
+ TP_PROTO(const struct netfs_io_request *wreq,
+ enum netfs_write_trace what),
+
+ TP_ARGS(wreq, what),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, wreq )
+ __field(unsigned int, cookie )
+ __field(enum netfs_write_trace, what )
+ __field(unsigned long long, start )
+ __field(size_t, len )
+ ),
+
+ TP_fast_assign(
+ struct netfs_inode *__ctx = netfs_inode(wreq->inode);
+ struct fscache_cookie *__cookie = netfs_i_cookie(__ctx);
+ __entry->wreq = wreq->debug_id;
+ __entry->cookie = __cookie ? __cookie->debug_id : 0;
+ __entry->what = what;
+ __entry->start = wreq->start;
+ __entry->len = wreq->len;
+ ),
+
+ TP_printk("R=%08x %s c=%08x by=%llx-%llx",
+ __entry->wreq,
+ __print_symbolic(__entry->what, netfs_write_traces),
+ __entry->cookie,
+ __entry->start, __entry->start + __entry->len - 1)
+ );
+
#undef EM
#undef E_
#endif /* _TRACE_NETFS_H */
Provide a netfs write helper, netfs_perform_write() to buffer data to be
written in the pagecache and mark the modified folios dirty.
It will perform "streaming writes" for folios that aren't currently
resident, if possible, storing data in partially modified folios that are
marked dirty, but not uptodate. It will also tag pages as belonging to
fs-specific write groups if so directed by the filesystem.
This is derived from generic_perform_write(), but doesn't use
->write_begin() and ->write_end(), having that logic rolled in instead.
Signed-off-by: David Howells <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/Makefile | 1 +
fs/netfs/buffered_read.c | 49 ++++++
fs/netfs/buffered_write.c | 330 +++++++++++++++++++++++++++++++++++
fs/netfs/internal.h | 2 +
fs/netfs/io.c | 1 +
include/linux/netfs.h | 5 +
include/trace/events/netfs.h | 73 ++++++++
7 files changed, 461 insertions(+)
create mode 100644 fs/netfs/buffered_write.c
diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
index c69c6775b8ac..85d8333a1ed4 100644
--- a/fs/netfs/Makefile
+++ b/fs/netfs/Makefile
@@ -2,6 +2,7 @@
netfs-y := \
buffered_read.o \
+ buffered_write.o \
io.o \
iterator.o \
locking.o \
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 6b9a44cafbac..73a6e4d61f9d 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -63,6 +63,7 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
break;
}
if (!folio_started && test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) {
+ trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache);
folio_start_fscache(folio);
folio_started = true;
}
@@ -454,3 +455,51 @@ int netfs_write_begin(struct netfs_inode *ctx,
return ret;
}
EXPORT_SYMBOL(netfs_write_begin);
+
+/*
+ * Preload the data into a page we're proposing to write into.
+ */
+int netfs_prefetch_for_write(struct file *file, struct folio *folio,
+ size_t offset, size_t len)
+{
+ struct netfs_io_request *rreq;
+ struct address_space *mapping = folio_file_mapping(folio);
+ struct netfs_inode *ctx = netfs_inode(mapping->host);
+ unsigned long long start = folio_pos(folio);
+ size_t flen = folio_size(folio);
+ int ret;
+
+ _enter("%zx @%llx", flen, start);
+
+ ret = -ENOMEM;
+
+ rreq = netfs_alloc_request(mapping, file, start, flen,
+ NETFS_READ_FOR_WRITE);
+ if (IS_ERR(rreq)) {
+ ret = PTR_ERR(rreq);
+ goto error;
+ }
+
+ rreq->no_unlock_folio = folio_index(folio);
+ __set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);
+ ret = netfs_begin_cache_read(rreq, ctx);
+ if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)
+ goto error_put;
+
+ netfs_stat(&netfs_n_rh_write_begin);
+ trace_netfs_read(rreq, start, flen, netfs_read_trace_prefetch_for_write);
+
+ /* Set up the output buffer */
+ iov_iter_xarray(&rreq->iter, ITER_DEST, &mapping->i_pages,
+ rreq->start, rreq->len);
+
+ ret = netfs_begin_read(rreq, true);
+ netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
+ return ret;
+
+error_put:
+ netfs_put_request(rreq, false, netfs_rreq_trace_put_discard);
+error:
+ _leave(" = %d", ret);
+ return ret;
+}
diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
new file mode 100644
index 000000000000..6e7f06d9962d
--- /dev/null
+++ b/fs/netfs/buffered_write.c
@@ -0,0 +1,330 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Network filesystem high-level write support.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells ([email protected])
+ */
+
+#include <linux/export.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/pagevec.h>
+#include "internal.h"
+
+/*
+ * Determined write method. Adjust netfs_folio_traces if this is changed.
+ */
+enum netfs_how_to_modify {
+ NETFS_FOLIO_IS_UPTODATE, /* Folio is uptodate already */
+ NETFS_JUST_PREFETCH, /* We have to read the folio anyway */
+ NETFS_WHOLE_FOLIO_MODIFY, /* We're going to overwrite the whole folio */
+ NETFS_MODIFY_AND_CLEAR, /* We can assume there is no data to be downloaded. */
+ NETFS_STREAMING_WRITE, /* Store incomplete data in non-uptodate page. */
+ NETFS_STREAMING_WRITE_CONT, /* Continue streaming write. */
+ NETFS_FLUSH_CONTENT, /* Flush incompatible content. */
+};
+
+static void netfs_set_group(struct folio *folio, struct netfs_group *netfs_group)
+{
+ if (netfs_group && !folio_get_private(folio))
+ folio_attach_private(folio, netfs_get_group(netfs_group));
+}
+
+/*
+ * Decide how we should modify a folio. We might be attempting to do
+ * write-streaming, in which case we don't want to a local RMW cycle if we can
+ * avoid it. If we're doing local caching or content crypto, we award that
+ * priority over avoiding RMW. If the file is open readably, then we also
+ * assume that we may want to read what we wrote.
+ */
+static enum netfs_how_to_modify netfs_how_to_modify(struct netfs_inode *ctx,
+ struct file *file,
+ struct folio *folio,
+ void *netfs_group,
+ size_t flen,
+ size_t offset,
+ size_t len,
+ bool maybe_trouble)
+{
+ struct netfs_folio *finfo = netfs_folio_info(folio);
+ loff_t pos = folio_file_pos(folio);
+
+ _enter("");
+
+ if (netfs_folio_group(folio) != netfs_group)
+ return NETFS_FLUSH_CONTENT;
+
+ if (folio_test_uptodate(folio))
+ return NETFS_FOLIO_IS_UPTODATE;
+
+ if (pos >= ctx->remote_i_size)
+ return NETFS_MODIFY_AND_CLEAR;
+
+ if (!maybe_trouble && offset == 0 && len >= flen)
+ return NETFS_WHOLE_FOLIO_MODIFY;
+
+ if (file->f_mode & FMODE_READ)
+ return NETFS_JUST_PREFETCH;
+
+ if (netfs_is_cache_enabled(ctx))
+ return NETFS_JUST_PREFETCH;
+
+ if (!finfo)
+ return NETFS_STREAMING_WRITE;
+
+ /* We can continue a streaming write only if it continues on from the
+ * previous. If it overlaps, we must flush lest we suffer a partial
+ * copy and disjoint dirty regions.
+ */
+ if (offset == finfo->dirty_offset + finfo->dirty_len)
+ return NETFS_STREAMING_WRITE_CONT;
+ return NETFS_FLUSH_CONTENT;
+}
+
+/*
+ * Grab a folio for writing and lock it.
+ */
+static struct folio *netfs_grab_folio_for_write(struct address_space *mapping,
+ loff_t pos, size_t part)
+{
+ pgoff_t index = pos / PAGE_SIZE;
+
+ return __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
+ mapping_gfp_mask(mapping));
+}
+
+/**
+ * netfs_perform_write - Copy data into the pagecache.
+ * @iocb: The operation parameters
+ * @iter: The source buffer
+ * @netfs_group: Grouping for dirty pages (eg. ceph snaps).
+ *
+ * Copy data into pagecache pages attached to the inode specified by @iocb.
+ * The caller must hold appropriate inode locks.
+ *
+ * Dirty pages are tagged with a netfs_folio struct if they're not up to date
+ * to indicate the range modified. Dirty pages may also be tagged with a
+ * netfs-specific grouping such that data from an old group gets flushed before
+ * a new one is started.
+ */
+ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
+ struct netfs_group *netfs_group)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file_inode(file);
+ struct address_space *mapping = inode->i_mapping;
+ struct netfs_inode *ctx = netfs_inode(inode);
+ struct netfs_folio *finfo;
+ struct folio *folio;
+ enum netfs_how_to_modify howto;
+ enum netfs_folio_trace trace;
+ unsigned int bdp_flags = (iocb->ki_flags & IOCB_SYNC) ? 0: BDP_ASYNC;
+ ssize_t written = 0, ret;
+ loff_t i_size, pos = iocb->ki_pos, from, to;
+ size_t max_chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER;
+ bool maybe_trouble = false;
+
+ do {
+ size_t flen;
+ size_t offset; /* Offset into pagecache folio */
+ size_t part; /* Bytes to write to folio */
+ size_t copied; /* Bytes copied from user */
+
+ ret = balance_dirty_pages_ratelimited_flags(mapping, bdp_flags);
+ if (unlikely(ret < 0))
+ break;
+
+ offset = pos & (max_chunk - 1);
+ part = min(max_chunk - offset, iov_iter_count(iter));
+
+ /* Bring in the user pages that we will copy from _first_ lest
+ * we hit a nasty deadlock on copying from the same page as
+ * we're writing to, without it being marked uptodate.
+ *
+ * Not only is this an optimisation, but it is also required to
+ * check that the address is actually valid, when atomic
+ * usercopies are used below.
+ *
+ * We rely on the page being held onto long enough by the LRU
+ * that we can grab it below if this causes it to be read.
+ */
+ ret = -EFAULT;
+ if (unlikely(fault_in_iov_iter_readable(iter, part) == part))
+ break;
+
+ ret = -ENOMEM;
+ folio = netfs_grab_folio_for_write(mapping, pos, part);
+ if (!folio)
+ break;
+
+ flen = folio_size(folio);
+ offset = pos & (flen - 1);
+ part = min_t(size_t, flen - offset, part);
+
+ if (signal_pending(current)) {
+ ret = written ? -EINTR : -ERESTARTSYS;
+ goto error_folio_unlock;
+ }
+
+ /* See if we need to prefetch the area we're going to modify.
+ * We need to do this before we get a lock on the folio in case
+ * there's more than one writer competing for the same cache
+ * block.
+ */
+ howto = netfs_how_to_modify(ctx, file, folio, netfs_group,
+ flen, offset, part, maybe_trouble);
+ _debug("howto %u", howto);
+ switch (howto) {
+ case NETFS_JUST_PREFETCH:
+ ret = netfs_prefetch_for_write(file, folio, offset, part);
+ if (ret < 0) {
+ _debug("prefetch = %zd", ret);
+ goto error_folio_unlock;
+ }
+ break;
+ case NETFS_FOLIO_IS_UPTODATE:
+ case NETFS_WHOLE_FOLIO_MODIFY:
+ case NETFS_STREAMING_WRITE_CONT:
+ break;
+ case NETFS_MODIFY_AND_CLEAR:
+ zero_user_segment(&folio->page, 0, offset);
+ break;
+ case NETFS_STREAMING_WRITE:
+ ret = -EIO;
+ if (WARN_ON(folio_get_private(folio)))
+ goto error_folio_unlock;
+ break;
+ case NETFS_FLUSH_CONTENT:
+ trace_netfs_folio(folio, netfs_flush_content);
+ from = folio_pos(folio);
+ to = from + folio_size(folio) - 1;
+ folio_unlock(folio);
+ folio_put(folio);
+ ret = filemap_write_and_wait_range(mapping, from, to);
+ if (ret < 0)
+ goto error_folio_unlock;
+ continue;
+ }
+
+ if (mapping_writably_mapped(mapping))
+ flush_dcache_folio(folio);
+
+ copied = copy_folio_from_iter_atomic(folio, offset, part, iter);
+
+ flush_dcache_folio(folio);
+
+ /* Deal with a (partially) failed copy */
+ if (copied == 0) {
+ ret = -EFAULT;
+ goto error_folio_unlock;
+ }
+
+ trace = (enum netfs_folio_trace)howto;
+ switch (howto) {
+ case NETFS_FOLIO_IS_UPTODATE:
+ case NETFS_JUST_PREFETCH:
+ netfs_set_group(folio, netfs_group);
+ break;
+ case NETFS_MODIFY_AND_CLEAR:
+ zero_user_segment(&folio->page, offset + copied, flen);
+ netfs_set_group(folio, netfs_group);
+ folio_mark_uptodate(folio);
+ break;
+ case NETFS_WHOLE_FOLIO_MODIFY:
+ if (unlikely(copied < part)) {
+ maybe_trouble = true;
+ iov_iter_revert(iter, copied);
+ copied = 0;
+ goto retry;
+ }
+ netfs_set_group(folio, netfs_group);
+ folio_mark_uptodate(folio);
+ break;
+ case NETFS_STREAMING_WRITE:
+ if (offset == 0 && copied == flen) {
+ netfs_set_group(folio, netfs_group);
+ folio_mark_uptodate(folio);
+ trace = netfs_streaming_filled_page;
+ break;
+ }
+ finfo = kzalloc(sizeof(*finfo), GFP_KERNEL);
+ if (!finfo) {
+ iov_iter_revert(iter, copied);
+ ret = -ENOMEM;
+ goto error_folio_unlock;
+ }
+ finfo->netfs_group = netfs_get_group(netfs_group);
+ finfo->dirty_offset = offset;
+ finfo->dirty_len = copied;
+ folio_attach_private(folio, (void *)((unsigned long)finfo |
+ NETFS_FOLIO_INFO));
+ break;
+ case NETFS_STREAMING_WRITE_CONT:
+ finfo = netfs_folio_info(folio);
+ finfo->dirty_len += copied;
+ if (finfo->dirty_offset == 0 && finfo->dirty_len == flen) {
+ if (finfo->netfs_group)
+ folio_change_private(folio, finfo->netfs_group);
+ else
+ folio_detach_private(folio);
+ folio_mark_uptodate(folio);
+ kfree(finfo);
+ trace = netfs_streaming_cont_filled_page;
+ }
+ break;
+ default:
+ WARN(true, "Unexpected modify type %u ix=%lx\n",
+ howto, folio_index(folio));
+ ret = -EIO;
+ goto error_folio_unlock;
+ }
+
+ trace_netfs_folio(folio, trace);
+
+ /* Update the inode size if we moved the EOF marker */
+ i_size = i_size_read(inode);
+ pos += copied;
+ if (pos > i_size) {
+ if (ctx->ops->update_i_size) {
+ ctx->ops->update_i_size(inode, pos);
+ } else {
+ i_size_write(inode, pos);
+#if IS_ENABLED(CONFIG_FSCACHE)
+ fscache_update_cookie(ctx->cache, NULL, &pos);
+#endif
+ }
+ }
+ written += copied;
+
+ folio_mark_dirty(folio);
+ retry:
+ folio_unlock(folio);
+ folio_put(folio);
+ folio = NULL;
+
+ cond_resched();
+ } while (iov_iter_count(iter));
+
+out:
+ if (likely(written)) {
+ /* Flush and wait for a write that requires immediate synchronisation. */
+ if (iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC)) {
+ _debug("dsync");
+ ret = filemap_fdatawait_range(mapping, iocb->ki_pos,
+ iocb->ki_pos + written);
+ }
+
+ iocb->ki_pos += written;
+ }
+
+ _leave(" = %zd [%zd]", written, ret);
+ return written ? written : ret;
+
+error_folio_unlock:
+ folio_unlock(folio);
+ folio_put(folio);
+ goto out;
+}
+EXPORT_SYMBOL(netfs_perform_write);
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 0f20587f5a9b..17e4ea4456c7 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -23,6 +23,8 @@
* buffered_read.c
*/
void netfs_rreq_unlock_folios(struct netfs_io_request *rreq);
+int netfs_prefetch_for_write(struct file *file, struct folio *folio,
+ size_t offset, size_t len);
/*
* io.c
diff --git a/fs/netfs/io.c b/fs/netfs/io.c
index e83ef5835d25..774aef6ea4cb 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -125,6 +125,7 @@ static void netfs_rreq_unmark_after_write(struct netfs_io_request *rreq,
if (have_unlocked && folio_index(folio) <= unlocked)
continue;
unlocked = folio_index(folio);
+ trace_netfs_folio(folio, netfs_folio_trace_end_copy);
folio_end_fscache(folio);
have_unlocked = true;
}
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 78d9f9486ee4..34b4cd9a56a6 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -368,6 +368,11 @@ struct netfs_cache_ops {
loff_t *_data_start, size_t *_data_len);
};
+/* High-level write API */
+ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
+ struct netfs_group *netfs_group);
+
+/* Address operations API */
struct readahead_control;
void netfs_readahead(struct readahead_control *);
int netfs_read_folio(struct file *, struct folio *);
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index e03635172760..8308b81f36be 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -19,6 +19,7 @@
EM(netfs_read_trace_expanded, "EXPANDED ") \
EM(netfs_read_trace_readahead, "READAHEAD") \
EM(netfs_read_trace_readpage, "READPAGE ") \
+ EM(netfs_read_trace_prefetch_for_write, "PREFETCHW") \
E_(netfs_read_trace_write_begin, "WRITEBEGN")
#define netfs_write_traces \
@@ -100,6 +101,31 @@
EM(netfs_sreq_trace_put_work, "PUT WORK ") \
E_(netfs_sreq_trace_put_terminated, "PUT TERM ")
+#define netfs_folio_traces \
+ /* The first few correspond to enum netfs_how_to_modify */ \
+ EM(netfs_folio_is_uptodate, "mod-uptodate") \
+ EM(netfs_just_prefetch, "mod-prefetch") \
+ EM(netfs_whole_folio_modify, "mod-whole-f") \
+ EM(netfs_modify_and_clear, "mod-n-clear") \
+ EM(netfs_streaming_write, "mod-streamw") \
+ EM(netfs_streaming_write_cont, "mod-streamw+") \
+ EM(netfs_flush_content, "flush") \
+ EM(netfs_streaming_filled_page, "mod-streamw-f") \
+ EM(netfs_streaming_cont_filled_page, "mod-streamw-f+") \
+ /* The rest are for writeback */ \
+ EM(netfs_folio_trace_clear, "clear") \
+ EM(netfs_folio_trace_clear_s, "clear-s") \
+ EM(netfs_folio_trace_clear_g, "clear-g") \
+ EM(netfs_folio_trace_copy_to_cache, "copy") \
+ EM(netfs_folio_trace_end_copy, "end-copy") \
+ EM(netfs_folio_trace_kill, "kill") \
+ EM(netfs_folio_trace_mkwrite, "mkwrite") \
+ EM(netfs_folio_trace_mkwrite_plus, "mkwrite+") \
+ EM(netfs_folio_trace_redirty, "redirty") \
+ EM(netfs_folio_trace_redirtied, "redirtied") \
+ EM(netfs_folio_trace_store, "store") \
+ E_(netfs_folio_trace_store_plus, "store+")
+
#ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
#define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
@@ -115,6 +141,7 @@ enum netfs_sreq_trace { netfs_sreq_traces } __mode(byte);
enum netfs_failure { netfs_failures } __mode(byte);
enum netfs_rreq_ref_trace { netfs_rreq_ref_traces } __mode(byte);
enum netfs_sreq_ref_trace { netfs_sreq_ref_traces } __mode(byte);
+enum netfs_folio_trace { netfs_folio_traces } __mode(byte);
#endif
@@ -135,6 +162,7 @@ netfs_sreq_traces;
netfs_failures;
netfs_rreq_ref_traces;
netfs_sreq_ref_traces;
+netfs_folio_traces;
/*
* Now redefine the EM() and E_() macros to map the enums to the strings that
@@ -335,6 +363,51 @@ TRACE_EVENT(netfs_sreq_ref,
__entry->ref)
);
+TRACE_EVENT(netfs_folio,
+ TP_PROTO(struct folio *folio, enum netfs_folio_trace why),
+
+ TP_ARGS(folio, why),
+
+ TP_STRUCT__entry(
+ __field(ino_t, ino)
+ __field(pgoff_t, index)
+ __field(unsigned int, nr)
+ __field(enum netfs_folio_trace, why)
+ ),
+
+ TP_fast_assign(
+ __entry->ino = folio->mapping->host->i_ino;
+ __entry->why = why;
+ __entry->index = folio_index(folio);
+ __entry->nr = folio_nr_pages(folio);
+ ),
+
+ TP_printk("i=%05lx ix=%05lx-%05lx %s",
+ __entry->ino, __entry->index, __entry->index + __entry->nr - 1,
+ __print_symbolic(__entry->why, netfs_folio_traces))
+ );
+
+TRACE_EVENT(netfs_write_iter,
+ TP_PROTO(const struct kiocb *iocb, const struct iov_iter *from),
+
+ TP_ARGS(iocb, from),
+
+ TP_STRUCT__entry(
+ __field(unsigned long long, start )
+ __field(size_t, len )
+ __field(unsigned int, flags )
+ ),
+
+ TP_fast_assign(
+ __entry->start = iocb->ki_pos;
+ __entry->len = iov_iter_count(from);
+ __entry->flags = iocb->ki_flags;
+ ),
+
+ TP_printk("WRITE-ITER s=%llx l=%zx f=%x",
+ __entry->start, __entry->len, __entry->flags)
+ );
+
TRACE_EVENT(netfs_write,
TP_PROTO(const struct netfs_io_request *wreq,
enum netfs_write_trace what),
netfs_read_folio() needs to handle partially-valid pages that are marked
dirty, but not uptodate in the event that someone tries to read a page was
used to cache data by a streaming write.
In such a case, make netfs_read_folio() set up a bvec iterator that points
to the parts of the folio that need filling and to a sink page for the data
that should be discarded and use that instead of i_pages as the iterator to
be written to.
This requires netfs_rreq_unlock_folios() to convert the page into a normal
dirty uptodate page, getting rid of the partial write record and bumping
the group pointer over to folio->private.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/buffered_read.c | 61 ++++++++++++++++++++++++++++++++++--
include/trace/events/netfs.h | 2 ++
2 files changed, 60 insertions(+), 3 deletions(-)
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 73a6e4d61f9d..950f63fc156a 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -16,6 +16,7 @@
void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
{
struct netfs_io_subrequest *subreq;
+ struct netfs_folio *finfo;
struct folio *folio;
pgoff_t start_page = rreq->start / PAGE_SIZE;
pgoff_t last_page = ((rreq->start + rreq->len) / PAGE_SIZE) - 1;
@@ -87,6 +88,15 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
if (!pg_failed) {
flush_dcache_folio(folio);
+ finfo = netfs_folio_info(folio);
+ if (finfo) {
+ trace_netfs_folio(folio, netfs_folio_trace_filled_gaps);
+ if (finfo->netfs_group)
+ folio_change_private(folio, finfo->netfs_group);
+ else
+ folio_detach_private(folio);
+ kfree(finfo);
+ }
folio_mark_uptodate(folio);
}
@@ -239,6 +249,7 @@ int netfs_read_folio(struct file *file, struct folio *folio)
struct address_space *mapping = folio_file_mapping(folio);
struct netfs_io_request *rreq;
struct netfs_inode *ctx = netfs_inode(mapping->host);
+ struct folio *sink = NULL;
int ret;
_enter("%lx", folio_index(folio));
@@ -259,12 +270,56 @@ int netfs_read_folio(struct file *file, struct folio *folio)
trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);
/* Set up the output buffer */
- iov_iter_xarray(&rreq->iter, ITER_DEST, &mapping->i_pages,
- rreq->start, rreq->len);
+ if (folio_test_dirty(folio)) {
+ /* Handle someone trying to read from an unflushed streaming
+ * write. We fiddle the buffer so that a gap at the beginning
+ * and/or a gap at the end get copied to, but the middle is
+ * discarded.
+ */
+ struct netfs_folio *finfo = netfs_folio_info(folio);
+ struct bio_vec *bvec;
+ unsigned int from = finfo->dirty_offset;
+ unsigned int to = from + finfo->dirty_len;
+ unsigned int off = 0, i = 0;
+ size_t flen = folio_size(folio);
+ size_t nr_bvec = flen / PAGE_SIZE + 2;
+ size_t part;
+
+ ret = -ENOMEM;
+ bvec = kmalloc_array(nr_bvec, sizeof(*bvec), GFP_KERNEL);
+ if (!bvec)
+ goto discard;
+
+ sink = folio_alloc(GFP_KERNEL, 0);
+ if (!sink)
+ goto discard;
+
+ trace_netfs_folio(folio, netfs_folio_trace_read_gaps);
+
+ rreq->direct_bv = bvec;
+ rreq->direct_bv_count = nr_bvec;
+ if (from > 0) {
+ bvec_set_folio(&bvec[i++], folio, from, 0);
+ off = from;
+ }
+ while (off < to) {
+ part = min_t(size_t, to - off, PAGE_SIZE);
+ bvec_set_folio(&bvec[i++], sink, part, 0);
+ off += part;
+ }
+ if (to < flen)
+ bvec_set_folio(&bvec[i++], folio, flen - to, to);
+ iov_iter_bvec(&rreq->iter, ITER_DEST, bvec, i, rreq->len);
+ } else {
+ iov_iter_xarray(&rreq->iter, ITER_DEST, &mapping->i_pages,
+ rreq->start, rreq->len);
+ }
ret = netfs_begin_read(rreq, true);
+ if (sink)
+ folio_put(sink);
netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
- return ret;
+ return ret < 0 ? ret : 0;
discard:
netfs_put_request(rreq, false, netfs_rreq_trace_put_discard);
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 8308b81f36be..082a5e717b58 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -118,9 +118,11 @@
EM(netfs_folio_trace_clear_g, "clear-g") \
EM(netfs_folio_trace_copy_to_cache, "copy") \
EM(netfs_folio_trace_end_copy, "end-copy") \
+ EM(netfs_folio_trace_filled_gaps, "filled-gaps") \
EM(netfs_folio_trace_kill, "kill") \
EM(netfs_folio_trace_mkwrite, "mkwrite") \
EM(netfs_folio_trace_mkwrite_plus, "mkwrite+") \
+ EM(netfs_folio_trace_read_gaps, "read-gaps") \
EM(netfs_folio_trace_redirty, "redirty") \
EM(netfs_folio_trace_redirtied, "redirtied") \
EM(netfs_folio_trace_store, "store") \
Allocate a multipage folio when copying data into the pagecache if possible
if there's sufficient data to warrant it.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/buffered_write.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 6e7f06d9962d..b76688e98f81 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -84,14 +84,19 @@ static enum netfs_how_to_modify netfs_how_to_modify(struct netfs_inode *ctx,
}
/*
- * Grab a folio for writing and lock it.
+ * Grab a folio for writing and lock it. Attempt to allocate as large a folio
+ * as possible to hold as much of the remaining length as possible in one go.
*/
static struct folio *netfs_grab_folio_for_write(struct address_space *mapping,
loff_t pos, size_t part)
{
pgoff_t index = pos / PAGE_SIZE;
+ fgf_t fgp_flags = FGP_WRITEBEGIN;
- return __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
+ if (mapping_large_folio_support(mapping))
+ fgp_flags |= fgf_set_order(pos % PAGE_SIZE + part);
+
+ return __filemap_get_folio(mapping, index, fgp_flags,
mapping_gfp_mask(mapping));
}
Implement support for unbuffered and DIO reads in the netfs library,
utilising the existing read helper code to do block splitting and
individual queuing. The code also handles extraction of the destination
buffer from the supplied iterator, allowing async unbuffered reads to take
place.
The read will be split up according to the rsize setting and, if supplied,
the ->clamp_length() method. Note that the next subrequest will be issued
as soon as issue_op returns, without waiting for previous ones to finish.
The network filesystem needs to pause or handle queuing them if it doesn't
want to fire them all at the server simultaneously.
Once all the subrequests have finished, the state will be assessed and the
amount of data to be indicated as having being obtained will be
determined. As the subrequests may finish in any order, if an intermediate
subrequest is short, any further subrequests may be copied into the buffer
and then abandoned.
In the future, this will also take care of doing an unbuffered read from
encrypted content, with the decryption being done by the library.
Signed-off-by: David Howells <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
Notes:
Changes
=======
ver #5)
- Drop bounce buffer handling.
fs/netfs/Makefile | 1 +
fs/netfs/direct_read.c | 125 +++++++++++++++++++++++++++++++++++
fs/netfs/internal.h | 1 +
fs/netfs/io.c | 83 ++++++++++++++++++++---
fs/netfs/main.c | 1 +
fs/netfs/objects.c | 5 +-
fs/netfs/stats.c | 4 +-
include/linux/netfs.h | 9 +++
include/trace/events/netfs.h | 7 +-
mm/filemap.c | 1 +
10 files changed, 226 insertions(+), 11 deletions(-)
create mode 100644 fs/netfs/direct_read.c
diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
index 85d8333a1ed4..e968ab1eca40 100644
--- a/fs/netfs/Makefile
+++ b/fs/netfs/Makefile
@@ -3,6 +3,7 @@
netfs-y := \
buffered_read.o \
buffered_write.o \
+ direct_read.o \
io.o \
iterator.o \
locking.o \
diff --git a/fs/netfs/direct_read.c b/fs/netfs/direct_read.c
new file mode 100644
index 000000000000..ad4370b3935d
--- /dev/null
+++ b/fs/netfs/direct_read.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Direct I/O support.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells ([email protected])
+ */
+
+#include <linux/export.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/uio.h>
+#include <linux/sched/mm.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/netfs.h>
+#include "internal.h"
+
+/**
+ * netfs_unbuffered_read_iter_locked - Perform an unbuffered or direct I/O read
+ * @iocb: The I/O control descriptor describing the read
+ * @iter: The output buffer (also specifies read length)
+ *
+ * Perform an unbuffered I/O or direct I/O from the file in @iocb to the
+ * output buffer. No use is made of the pagecache.
+ *
+ * The caller must hold any appropriate locks.
+ */
+static ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_iter *iter)
+{
+ struct netfs_io_request *rreq;
+ ssize_t ret;
+ size_t orig_count = iov_iter_count(iter);
+ bool async = !is_sync_kiocb(iocb);
+
+ _enter("");
+
+ if (!orig_count)
+ return 0; /* Don't update atime */
+
+ ret = kiocb_write_and_wait(iocb, orig_count);
+ if (ret < 0)
+ return ret;
+ file_accessed(iocb->ki_filp);
+
+ rreq = netfs_alloc_request(iocb->ki_filp->f_mapping, iocb->ki_filp,
+ iocb->ki_pos, orig_count,
+ NETFS_DIO_READ);
+ if (IS_ERR(rreq))
+ return PTR_ERR(rreq);
+
+ netfs_stat(&netfs_n_rh_dio_read);
+ trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_dio_read);
+
+ /* If this is an async op, we have to keep track of the destination
+ * buffer for ourselves as the caller's iterator will be trashed when
+ * we return.
+ *
+ * In such a case, extract an iterator to represent as much of the the
+ * output buffer as we can manage. Note that the extraction might not
+ * be able to allocate a sufficiently large bvec array and may shorten
+ * the request.
+ */
+ if (user_backed_iter(iter)) {
+ ret = netfs_extract_user_iter(iter, rreq->len, &rreq->iter, 0);
+ if (ret < 0)
+ goto out;
+ rreq->direct_bv = (struct bio_vec *)rreq->iter.bvec;
+ rreq->direct_bv_count = ret;
+ rreq->direct_bv_unpin = iov_iter_extract_will_pin(iter);
+ rreq->len = iov_iter_count(&rreq->iter);
+ } else {
+ rreq->iter = *iter;
+ rreq->len = orig_count;
+ rreq->direct_bv_unpin = false;
+ iov_iter_advance(iter, orig_count);
+ }
+
+ // TODO: Set up bounce buffer if needed
+
+ if (async)
+ rreq->iocb = iocb;
+
+ ret = netfs_begin_read(rreq, is_sync_kiocb(iocb));
+ if (ret < 0)
+ goto out; /* May be -EIOCBQUEUED */
+ if (!async) {
+ // TODO: Copy from bounce buffer
+ iocb->ki_pos += rreq->transferred;
+ ret = rreq->transferred;
+ }
+
+out:
+ netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
+ if (ret > 0)
+ orig_count -= ret;
+ if (ret != -EIOCBQUEUED)
+ iov_iter_revert(iter, orig_count - iov_iter_count(iter));
+ return ret;
+}
+
+/**
+ * netfs_unbuffered_read_iter - Perform an unbuffered or direct I/O read
+ * @iocb: The I/O control descriptor describing the read
+ * @iter: The output buffer (also specifies read length)
+ *
+ * Perform an unbuffered I/O or direct I/O from the file in @iocb to the
+ * output buffer. No use is made of the pagecache.
+ */
+ssize_t netfs_unbuffered_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ ssize_t ret;
+
+ if (!iter->count)
+ return 0; /* Don't update atime */
+
+ ret = netfs_start_io_direct(inode);
+ if (ret == 0) {
+ ret = netfs_unbuffered_read_iter_locked(iocb, iter);
+ netfs_end_io_direct(inode);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(netfs_unbuffered_read_iter);
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 17e4ea4456c7..886c2e8f841f 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -100,6 +100,7 @@ int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
* stats.c
*/
#ifdef CONFIG_NETFS_STATS
+extern atomic_t netfs_n_rh_dio_read;
extern atomic_t netfs_n_rh_readahead;
extern atomic_t netfs_n_rh_readpage;
extern atomic_t netfs_n_rh_rreq;
diff --git a/fs/netfs/io.c b/fs/netfs/io.c
index 774aef6ea4cb..c972415c8aad 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -78,7 +78,9 @@ static void netfs_read_from_server(struct netfs_io_request *rreq,
struct netfs_io_subrequest *subreq)
{
netfs_stat(&netfs_n_rh_download);
- if (iov_iter_count(&subreq->io_iter) != subreq->len - subreq->transferred)
+
+ if (rreq->origin != NETFS_DIO_READ &&
+ iov_iter_count(&subreq->io_iter) != subreq->len - subreq->transferred)
pr_warn("R=%08x[%u] ITER PRE-MISMATCH %zx != %zx-%zx %lx\n",
rreq->debug_id, subreq->debug_index,
iov_iter_count(&subreq->io_iter), subreq->len,
@@ -341,6 +343,43 @@ static void netfs_rreq_is_still_valid(struct netfs_io_request *rreq)
}
}
+/*
+ * Determine how much we can admit to having read from a DIO read.
+ */
+static void netfs_rreq_assess_dio(struct netfs_io_request *rreq)
+{
+ struct netfs_io_subrequest *subreq;
+ unsigned int i;
+ size_t transferred = 0;
+
+ for (i = 0; i < rreq->direct_bv_count; i++)
+ flush_dcache_page(rreq->direct_bv[i].bv_page);
+
+ list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
+ if (subreq->error || subreq->transferred == 0)
+ break;
+ transferred += subreq->transferred;
+ if (subreq->transferred < subreq->len)
+ break;
+ }
+
+ for (i = 0; i < rreq->direct_bv_count; i++)
+ flush_dcache_page(rreq->direct_bv[i].bv_page);
+
+ rreq->transferred = transferred;
+ task_io_account_read(transferred);
+
+ if (rreq->iocb) {
+ rreq->iocb->ki_pos += transferred;
+ if (rreq->iocb->ki_complete)
+ rreq->iocb->ki_complete(
+ rreq->iocb, rreq->error ? rreq->error : transferred);
+ }
+ if (rreq->netfs_ops->done)
+ rreq->netfs_ops->done(rreq);
+ inode_dio_end(rreq->inode);
+}
+
/*
* Assess the state of a read request and decide what to do next.
*
@@ -361,7 +400,10 @@ static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
return;
}
- netfs_rreq_unlock_folios(rreq);
+ if (rreq->origin != NETFS_DIO_READ)
+ netfs_rreq_unlock_folios(rreq);
+ else
+ netfs_rreq_assess_dio(rreq);
trace_netfs_rreq(rreq, netfs_rreq_trace_wake_ip);
clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
@@ -526,14 +568,16 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
struct netfs_io_subrequest *subreq,
struct iov_iter *io_iter)
{
- enum netfs_io_source source;
+ enum netfs_io_source source = NETFS_DOWNLOAD_FROM_SERVER;
size_t lsize;
_enter("%llx-%llx,%llx", subreq->start, subreq->start + subreq->len, rreq->i_size);
- source = netfs_cache_prepare_read(subreq, rreq->i_size);
- if (source == NETFS_INVALID_READ)
- goto out;
+ if (rreq->origin != NETFS_DIO_READ) {
+ source = netfs_cache_prepare_read(subreq, rreq->i_size);
+ if (source == NETFS_INVALID_READ)
+ goto out;
+ }
if (source == NETFS_DOWNLOAD_FROM_SERVER) {
/* Call out to the netfs to let it shrink the request to fit
@@ -544,6 +588,8 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
*/
if (subreq->len > rreq->i_size - subreq->start)
subreq->len = rreq->i_size - subreq->start;
+ if (rreq->rsize && subreq->len > rreq->rsize)
+ subreq->len = rreq->rsize;
if (rreq->netfs_ops->clamp_length &&
!rreq->netfs_ops->clamp_length(subreq)) {
@@ -662,6 +708,10 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
return -EIO;
}
+ if (rreq->origin == NETFS_DIO_READ)
+ inode_dio_begin(rreq->inode);
+
+ // TODO: Use bounce buffer if requested
rreq->io_iter = rreq->iter;
INIT_WORK(&rreq->work, netfs_rreq_work);
@@ -673,11 +723,25 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
atomic_set(&rreq->nr_outstanding, 1);
io_iter = rreq->io_iter;
do {
+ _debug("submit %llx + %zx >= %llx",
+ rreq->start, rreq->submitted, rreq->i_size);
+ if (rreq->origin == NETFS_DIO_READ &&
+ rreq->start + rreq->submitted >= rreq->i_size)
+ break;
if (!netfs_rreq_submit_slice(rreq, &io_iter, &debug_index))
break;
+ if (test_bit(NETFS_RREQ_BLOCKED, &rreq->flags) &&
+ test_bit(NETFS_RREQ_NONBLOCK, &rreq->flags))
+ break;
} while (rreq->submitted < rreq->len);
+ if (!rreq->submitted) {
+ netfs_put_request(rreq, false, netfs_rreq_trace_put_no_submit);
+ ret = 0;
+ goto out;
+ }
+
if (sync) {
/* Keep nr_outstanding incremented so that the ref always
* belongs to us, and the service code isn't punted off to a
@@ -694,7 +758,8 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
TASK_UNINTERRUPTIBLE);
ret = rreq->error;
- if (ret == 0 && rreq->submitted < rreq->len) {
+ if (ret == 0 && rreq->submitted < rreq->len &&
+ rreq->origin != NETFS_DIO_READ) {
trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read);
ret = -EIO;
}
@@ -702,7 +767,9 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync)
/* If we decrement nr_outstanding to 0, the ref belongs to us. */
if (atomic_dec_and_test(&rreq->nr_outstanding))
netfs_rreq_assess(rreq, false);
- ret = 0;
+ ret = -EIOCBQUEUED;
}
+
+out:
return ret;
}
diff --git a/fs/netfs/main.c b/fs/netfs/main.c
index ab6cac110676..abb8857486ee 100644
--- a/fs/netfs/main.c
+++ b/fs/netfs/main.c
@@ -30,6 +30,7 @@ static const char *netfs_origins[nr__netfs_io_origin] = {
[NETFS_READPAGE] = "RP",
[NETFS_READ_FOR_WRITE] = "RW",
[NETFS_WRITEBACK] = "WB",
+ [NETFS_DIO_READ] = "DR",
};
/*
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index 3aa0bfbc04ec..7153f24e8034 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -20,7 +20,8 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
struct inode *inode = file ? file_inode(file) : mapping->host;
struct netfs_inode *ctx = netfs_inode(inode);
struct netfs_io_request *rreq;
- bool cached = netfs_is_cache_enabled(ctx);
+ bool is_dio = (origin == NETFS_DIO_READ);
+ bool cached = is_dio && netfs_is_cache_enabled(ctx);
int ret;
rreq = kzalloc(ctx->ops->io_request_size ?: sizeof(struct netfs_io_request),
@@ -42,6 +43,8 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
if (cached)
__set_bit(NETFS_RREQ_WRITE_TO_CACHE, &rreq->flags);
+ if (file && file->f_flags & O_NONBLOCK)
+ __set_bit(NETFS_RREQ_NONBLOCK, &rreq->flags);
if (rreq->netfs_ops->init_request) {
ret = rreq->netfs_ops->init_request(rreq, file);
if (ret < 0) {
diff --git a/fs/netfs/stats.c b/fs/netfs/stats.c
index c1f85cd595a4..15fd5c3f0f39 100644
--- a/fs/netfs/stats.c
+++ b/fs/netfs/stats.c
@@ -9,6 +9,7 @@
#include <linux/seq_file.h>
#include "internal.h"
+atomic_t netfs_n_rh_dio_read;
atomic_t netfs_n_rh_readahead;
atomic_t netfs_n_rh_readpage;
atomic_t netfs_n_rh_rreq;
@@ -36,7 +37,8 @@ atomic_t netfs_n_wh_write_failed;
int netfs_stats_show(struct seq_file *m, void *v)
{
- seq_printf(m, "Netfs : RA=%u RP=%u WB=%u WBZ=%u rr=%u sr=%u\n",
+ seq_printf(m, "Netfs : DR=%u RA=%u RP=%u WB=%u WBZ=%u rr=%u sr=%u\n",
+ atomic_read(&netfs_n_rh_dio_read),
atomic_read(&netfs_n_rh_readahead),
atomic_read(&netfs_n_rh_readpage),
atomic_read(&netfs_n_rh_write_begin),
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 34b4cd9a56a6..784afaff8c78 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -226,6 +226,7 @@ enum netfs_io_origin {
NETFS_READPAGE, /* This read is a synchronous read */
NETFS_READ_FOR_WRITE, /* This read is to prepare a write */
NETFS_WRITEBACK, /* This write was triggered by writepages */
+ NETFS_DIO_READ, /* This is a direct I/O read */
nr__netfs_io_origin
} __mode(byte);
@@ -240,6 +241,7 @@ struct netfs_io_request {
};
struct inode *inode; /* The file being accessed */
struct address_space *mapping; /* The mapping being accessed */
+ struct kiocb *iocb; /* AIO completion vector */
struct netfs_cache_resources cache_resources;
struct list_head proc_link; /* Link in netfs_iorequests */
struct list_head subrequests; /* Contributory I/O operations */
@@ -250,12 +252,14 @@ struct netfs_io_request {
__counted_by(direct_bv_count);
unsigned int direct_bv_count; /* Number of elements in direct_bv[] */
unsigned int debug_id;
+ unsigned int rsize; /* Maximum read size (0 for none) */
unsigned int wsize; /* Maximum write size (0 for none) */
unsigned int subreq_counter; /* Next subreq->debug_index */
atomic_t nr_outstanding; /* Number of ops in progress */
atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */
size_t submitted; /* Amount submitted for I/O so far */
size_t len; /* Length of the request */
+ size_t transferred; /* Amount to be indicated as transferred */
short error; /* 0 or error that occurred */
enum netfs_io_origin origin; /* Origin of the request */
bool direct_bv_unpin; /* T if direct_bv[] must be unpinned */
@@ -272,6 +276,8 @@ struct netfs_io_request {
#define NETFS_RREQ_IN_PROGRESS 5 /* Unlocked when the request completes */
#define NETFS_RREQ_WRITE_TO_CACHE 7 /* Need to write to the cache */
#define NETFS_RREQ_UPLOAD_TO_SERVER 8 /* Need to write to the server */
+#define NETFS_RREQ_NONBLOCK 9 /* Don't block if possible (O_NONBLOCK) */
+#define NETFS_RREQ_BLOCKED 10 /* We blocked */
const struct netfs_request_ops *netfs_ops;
void (*cleanup)(struct netfs_io_request *req);
};
@@ -368,6 +374,9 @@ struct netfs_cache_ops {
loff_t *_data_start, size_t *_data_len);
};
+/* High-level read API. */
+ssize_t netfs_unbuffered_read_iter(struct kiocb *iocb, struct iov_iter *iter);
+
/* High-level write API */
ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
struct netfs_group *netfs_group);
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 082a5e717b58..5a4edadf0e59 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -16,6 +16,7 @@
* Define enums for tracing information.
*/
#define netfs_read_traces \
+ EM(netfs_read_trace_dio_read, "DIO-READ ") \
EM(netfs_read_trace_expanded, "EXPANDED ") \
EM(netfs_read_trace_readahead, "READAHEAD") \
EM(netfs_read_trace_readpage, "READPAGE ") \
@@ -31,7 +32,8 @@
EM(NETFS_READAHEAD, "RA") \
EM(NETFS_READPAGE, "RP") \
EM(NETFS_READ_FOR_WRITE, "RW") \
- E_(NETFS_WRITEBACK, "WB")
+ EM(NETFS_WRITEBACK, "WB") \
+ E_(NETFS_DIO_READ, "DR")
#define netfs_rreq_traces \
EM(netfs_rreq_trace_assess, "ASSESS ") \
@@ -70,6 +72,8 @@
#define netfs_failures \
EM(netfs_fail_check_write_begin, "check-write-begin") \
EM(netfs_fail_copy_to_cache, "copy-to-cache") \
+ EM(netfs_fail_dio_read_short, "dio-read-short") \
+ EM(netfs_fail_dio_read_zero, "dio-read-zero") \
EM(netfs_fail_read, "read") \
EM(netfs_fail_short_read, "short-read") \
EM(netfs_fail_prepare_write, "prep-write") \
@@ -81,6 +85,7 @@
EM(netfs_rreq_trace_put_complete, "PUT COMPLT ") \
EM(netfs_rreq_trace_put_discard, "PUT DISCARD") \
EM(netfs_rreq_trace_put_failed, "PUT FAILED ") \
+ EM(netfs_rreq_trace_put_no_submit, "PUT NO-SUBM") \
EM(netfs_rreq_trace_put_return, "PUT RETURN ") \
EM(netfs_rreq_trace_put_subreq, "PUT SUBREQ ") \
EM(netfs_rreq_trace_put_work, "PUT WORK ") \
diff --git a/mm/filemap.c b/mm/filemap.c
index f1c8c278310f..1c5271ed0cc0 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2678,6 +2678,7 @@ int kiocb_write_and_wait(struct kiocb *iocb, size_t count)
return filemap_write_and_wait_range(mapping, pos, end);
}
+EXPORT_SYMBOL_GPL(kiocb_write_and_wait);
int kiocb_invalidate_pages(struct kiocb *iocb, size_t count)
{
Provide an entry point to delegate a filesystem's ->page_mkwrite() to.
This checks for conflicting writes, then attached any netfs-specific group
marking (e.g. ceph snap) to the page to be considered dirty.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/buffered_write.c | 59 +++++++++++++++++++++++++++++++++++++++
include/linux/netfs.h | 4 +++
2 files changed, 63 insertions(+)
diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index f244123ab568..70cb8e98d068 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -416,3 +416,62 @@ ssize_t netfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
return ret;
}
EXPORT_SYMBOL(netfs_file_write_iter);
+
+/*
+ * Notification that a previously read-only page is about to become writable.
+ * Note that the caller indicates a single page of a multipage folio.
+ */
+vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_group)
+{
+ struct folio *folio = page_folio(vmf->page);
+ struct file *file = vmf->vma->vm_file;
+ struct inode *inode = file_inode(file);
+ vm_fault_t ret = VM_FAULT_RETRY;
+ int err;
+
+ _enter("%lx", folio->index);
+
+ sb_start_pagefault(inode->i_sb);
+
+ if (folio_wait_writeback_killable(folio))
+ goto out;
+
+ if (folio_lock_killable(folio) < 0)
+ goto out;
+
+ /* Can we see a streaming write here? */
+ if (WARN_ON(!folio_test_uptodate(folio))) {
+ ret = VM_FAULT_SIGBUS | VM_FAULT_LOCKED;
+ goto out;
+ }
+
+ if (netfs_folio_group(folio) != netfs_group) {
+ folio_unlock(folio);
+ err = filemap_fdatawait_range(inode->i_mapping,
+ folio_pos(folio),
+ folio_pos(folio) + folio_size(folio));
+ switch (err) {
+ case 0:
+ ret = VM_FAULT_RETRY;
+ goto out;
+ case -ENOMEM:
+ ret = VM_FAULT_OOM;
+ goto out;
+ default:
+ ret = VM_FAULT_SIGBUS;
+ goto out;
+ }
+ }
+
+ if (folio_test_dirty(folio))
+ trace_netfs_folio(folio, netfs_folio_trace_mkwrite_plus);
+ else
+ trace_netfs_folio(folio, netfs_folio_trace_mkwrite);
+ netfs_set_group(folio, netfs_group);
+ file_update_time(file);
+ ret = VM_FAULT_LOCKED;
+out:
+ sb_end_pagefault(inode->i_sb);
+ return ret;
+}
+EXPORT_SYMBOL(netfs_page_mkwrite);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 5c225f308704..e444f814dd56 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -401,6 +401,10 @@ void netfs_clear_inode_writeback(struct inode *inode, const void *aux);
void netfs_invalidate_folio(struct folio *folio, size_t offset, size_t length);
bool netfs_release_folio(struct folio *folio, gfp_t gfp);
+/* VMA operations API. */
+vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_group);
+
+/* (Sub)request management API. */
void netfs_subreq_terminated(struct netfs_io_subrequest *, ssize_t, bool);
void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
enum netfs_sreq_ref_trace what);
Provide a top-level-ish function that can be pointed to directly by
->read_iter file op.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/buffered_read.c | 73 ++++++++++++++++++++++++++++++++++++++++
include/linux/netfs.h | 2 ++
2 files changed, 75 insertions(+)
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 950f63fc156a..a59e7b2edaac 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -558,3 +558,76 @@ int netfs_prefetch_for_write(struct file *file, struct folio *folio,
_leave(" = %d", ret);
return ret;
}
+
+/**
+ * netfs_buffered_read_iter - Filesystem buffered I/O read routine
+ * @iocb: kernel I/O control block
+ * @iter: destination for the data read
+ *
+ * This is the ->read_iter() routine for all filesystems that can use the page
+ * cache directly.
+ *
+ * The IOCB_NOWAIT flag in iocb->ki_flags indicates that -EAGAIN shall be
+ * returned when no data can be read without waiting for I/O requests to
+ * complete; it doesn't prevent readahead.
+ *
+ * The IOCB_NOIO flag in iocb->ki_flags indicates that no new I/O requests
+ * shall be made for the read or for readahead. When no data can be read,
+ * -EAGAIN shall be returned. When readahead would be triggered, a partial,
+ * possibly empty read shall be returned.
+ *
+ * Return:
+ * * number of bytes copied, even for partial reads
+ * * negative error code (or 0 if IOCB_NOIO) if nothing was read
+ */
+ssize_t netfs_buffered_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct netfs_inode *ictx = netfs_inode(inode);
+ ssize_t ret;
+
+ if (WARN_ON_ONCE((iocb->ki_flags & IOCB_DIRECT) ||
+ test_bit(NETFS_ICTX_UNBUFFERED, &ictx->flags)))
+ return -EINVAL;
+
+ ret = netfs_start_io_read(inode);
+ if (ret == 0) {
+ ret = filemap_read(iocb, iter, 0);
+ netfs_end_io_read(inode);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(netfs_buffered_read_iter);
+
+/**
+ * netfs_file_read_iter - Generic filesystem read routine
+ * @iocb: kernel I/O control block
+ * @iter: destination for the data read
+ *
+ * This is the ->read_iter() routine for all filesystems that can use the page
+ * cache directly.
+ *
+ * The IOCB_NOWAIT flag in iocb->ki_flags indicates that -EAGAIN shall be
+ * returned when no data can be read without waiting for I/O requests to
+ * complete; it doesn't prevent readahead.
+ *
+ * The IOCB_NOIO flag in iocb->ki_flags indicates that no new I/O requests
+ * shall be made for the read or for readahead. When no data can be read,
+ * -EAGAIN shall be returned. When readahead would be triggered, a partial,
+ * possibly empty read shall be returned.
+ *
+ * Return:
+ * * number of bytes copied, even for partial reads
+ * * negative error code (or 0 if IOCB_NOIO) if nothing was read
+ */
+ssize_t netfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+ struct netfs_inode *ictx = netfs_inode(iocb->ki_filp->f_mapping->host);
+
+ if ((iocb->ki_flags & IOCB_DIRECT) ||
+ test_bit(NETFS_ICTX_UNBUFFERED, &ictx->flags))
+ return netfs_unbuffered_read_iter(iocb, iter);
+
+ return netfs_buffered_read_iter(iocb, iter);
+}
+EXPORT_SYMBOL(netfs_file_read_iter);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index e444f814dd56..a2e53ab06a1b 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -379,6 +379,8 @@ struct netfs_cache_ops {
/* High-level read API. */
ssize_t netfs_unbuffered_read_iter(struct kiocb *iocb, struct iov_iter *iter);
+ssize_t netfs_buffered_read_iter(struct kiocb *iocb, struct iov_iter *iter);
+ssize_t netfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
/* High-level write API */
ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
Provide an implementation of writepages for network filesystems to delegate
to.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
Notes:
Changes
=======
ver #5)
- Use netfs_folio_info() rather than open-coding pointer mangling.
- Use folio_get_private() rather than using folio->private.
- Don't check the folio private pointer before taking the folio ref during
writeback pagecache RCU xarray walk.
fs/netfs/buffered_write.c | 636 ++++++++++++++++++++++++++++++++++++++
include/linux/netfs.h | 2 +
2 files changed, 638 insertions(+)
diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 70cb8e98d068..c078826f7fe6 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -32,6 +32,18 @@ static void netfs_set_group(struct folio *folio, struct netfs_group *netfs_group
folio_attach_private(folio, netfs_get_group(netfs_group));
}
+#if IS_ENABLED(CONFIG_FSCACHE)
+static void netfs_folio_start_fscache(bool caching, struct folio *folio)
+{
+ if (caching)
+ folio_start_fscache(folio);
+}
+#else
+static void netfs_folio_start_fscache(bool caching, struct folio *folio)
+{
+}
+#endif
+
/*
* Decide how we should modify a folio. We might be attempting to do
* write-streaming, in which case we don't want to a local RMW cycle if we can
@@ -475,3 +487,627 @@ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_gr
return ret;
}
EXPORT_SYMBOL(netfs_page_mkwrite);
+
+/*
+ * Kill all the pages in the given range
+ */
+static void netfs_kill_pages(struct address_space *mapping,
+ loff_t start, loff_t len)
+{
+ struct folio *folio;
+ pgoff_t index = start / PAGE_SIZE;
+ pgoff_t last = (start + len - 1) / PAGE_SIZE, next;
+
+ _enter("%llx-%llx", start, start + len - 1);
+
+ do {
+ _debug("kill %lx (to %lx)", index, last);
+
+ folio = filemap_get_folio(mapping, index);
+ if (IS_ERR(folio)) {
+ next = index + 1;
+ continue;
+ }
+
+ next = folio_next_index(folio);
+
+ trace_netfs_folio(folio, netfs_folio_trace_kill);
+ folio_clear_uptodate(folio);
+ if (folio_test_fscache(folio))
+ folio_end_fscache(folio);
+ folio_end_writeback(folio);
+ folio_lock(folio);
+ generic_error_remove_page(mapping, &folio->page);
+ folio_unlock(folio);
+ folio_put(folio);
+
+ } while (index = next, index <= last);
+
+ _leave("");
+}
+
+/*
+ * Redirty all the pages in a given range.
+ */
+static void netfs_redirty_pages(struct address_space *mapping,
+ loff_t start, loff_t len)
+{
+ struct folio *folio;
+ pgoff_t index = start / PAGE_SIZE;
+ pgoff_t last = (start + len - 1) / PAGE_SIZE, next;
+
+ _enter("%llx-%llx", start, start + len - 1);
+
+ do {
+ _debug("redirty %llx @%llx", len, start);
+
+ folio = filemap_get_folio(mapping, index);
+ if (IS_ERR(folio)) {
+ next = index + 1;
+ continue;
+ }
+
+ next = folio_next_index(folio);
+ trace_netfs_folio(folio, netfs_folio_trace_redirty);
+ filemap_dirty_folio(mapping, folio);
+ if (folio_test_fscache(folio))
+ folio_end_fscache(folio);
+ folio_end_writeback(folio);
+ folio_put(folio);
+ } while (index = next, index <= last);
+
+ balance_dirty_pages_ratelimited(mapping);
+
+ _leave("");
+}
+
+/*
+ * Completion of write to server
+ */
+static void netfs_pages_written_back(struct netfs_io_request *wreq)
+{
+ struct address_space *mapping = wreq->mapping;
+ struct netfs_folio *finfo;
+ struct netfs_group *group = NULL;
+ struct folio *folio;
+ pgoff_t last;
+ int gcount = 0;
+
+ XA_STATE(xas, &mapping->i_pages, wreq->start / PAGE_SIZE);
+
+ _enter("%llx-%llx", wreq->start, wreq->start + wreq->len);
+
+ rcu_read_lock();
+
+ last = (wreq->start + wreq->len - 1) / PAGE_SIZE;
+ xas_for_each(&xas, folio, last) {
+ WARN(!folio_test_writeback(folio),
+ "bad %zx @%llx page %lx %lx\n",
+ wreq->len, wreq->start, folio_index(folio), last);
+
+ if ((finfo = netfs_folio_info(folio))) {
+ /* Streaming writes cannot be redirtied whilst under
+ * writeback, so discard the streaming record.
+ */
+ folio_detach_private(folio);
+ group = finfo->netfs_group;
+ gcount++;
+ trace_netfs_folio(folio, netfs_folio_trace_clear_s);
+ kfree(finfo);
+ } else if ((group = netfs_folio_group(folio))) {
+ /* Need to detach the group pointer if the page didn't
+ * get redirtied. If it has been redirtied, then it
+ * must be within the same group.
+ */
+ if (folio_test_dirty(folio)) {
+ trace_netfs_folio(folio, netfs_folio_trace_redirtied);
+ goto end_wb;
+ }
+ if (folio_trylock(folio)) {
+ if (!folio_test_dirty(folio)) {
+ folio_detach_private(folio);
+ gcount++;
+ trace_netfs_folio(folio, netfs_folio_trace_clear_g);
+ } else {
+ trace_netfs_folio(folio, netfs_folio_trace_redirtied);
+ }
+ folio_unlock(folio);
+ goto end_wb;
+ }
+
+ xas_pause(&xas);
+ rcu_read_unlock();
+ folio_lock(folio);
+ if (!folio_test_dirty(folio)) {
+ folio_detach_private(folio);
+ gcount++;
+ trace_netfs_folio(folio, netfs_folio_trace_clear_g);
+ } else {
+ trace_netfs_folio(folio, netfs_folio_trace_redirtied);
+ }
+ folio_unlock(folio);
+ rcu_read_lock();
+ } else {
+ trace_netfs_folio(folio, netfs_folio_trace_clear);
+ }
+ end_wb:
+ if (folio_test_fscache(folio))
+ folio_end_fscache(folio);
+ folio_end_writeback(folio);
+ }
+
+ rcu_read_unlock();
+ netfs_put_group_many(group, gcount);
+ _leave("");
+}
+
+/*
+ * Deal with the disposition of the folios that are under writeback to close
+ * out the operation.
+ */
+static void netfs_cleanup_buffered_write(struct netfs_io_request *wreq)
+{
+ struct address_space *mapping = wreq->mapping;
+
+ _enter("");
+
+ switch (wreq->error) {
+ case 0:
+ netfs_pages_written_back(wreq);
+ break;
+
+ default:
+ pr_notice("R=%08x Unexpected error %d\n", wreq->debug_id, wreq->error);
+ fallthrough;
+ case -EACCES:
+ case -EPERM:
+ case -ENOKEY:
+ case -EKEYEXPIRED:
+ case -EKEYREJECTED:
+ case -EKEYREVOKED:
+ case -ENETRESET:
+ case -EDQUOT:
+ case -ENOSPC:
+ netfs_redirty_pages(mapping, wreq->start, wreq->len);
+ break;
+
+ case -EROFS:
+ case -EIO:
+ case -EREMOTEIO:
+ case -EFBIG:
+ case -ENOENT:
+ case -ENOMEDIUM:
+ case -ENXIO:
+ netfs_kill_pages(mapping, wreq->start, wreq->len);
+ break;
+ }
+
+ if (wreq->error)
+ mapping_set_error(mapping, wreq->error);
+ if (wreq->netfs_ops->done)
+ wreq->netfs_ops->done(wreq);
+}
+
+/*
+ * Extend the region to be written back to include subsequent contiguously
+ * dirty pages if possible, but don't sleep while doing so.
+ *
+ * If this page holds new content, then we can include filler zeros in the
+ * writeback.
+ */
+static void netfs_extend_writeback(struct address_space *mapping,
+ struct netfs_group *group,
+ struct xa_state *xas,
+ long *_count,
+ loff_t start,
+ loff_t max_len,
+ bool caching,
+ size_t *_len,
+ size_t *_top)
+{
+ struct netfs_folio *finfo;
+ struct folio_batch fbatch;
+ struct folio *folio;
+ unsigned int i;
+ pgoff_t index = (start + *_len) / PAGE_SIZE;
+ size_t len;
+ void *priv;
+ bool stop = true;
+
+ folio_batch_init(&fbatch);
+
+ do {
+ /* Firstly, we gather up a batch of contiguous dirty pages
+ * under the RCU read lock - but we can't clear the dirty flags
+ * there if any of those pages are mapped.
+ */
+ rcu_read_lock();
+
+ xas_for_each(xas, folio, ULONG_MAX) {
+ stop = true;
+ if (xas_retry(xas, folio))
+ continue;
+ if (xa_is_value(folio))
+ break;
+ if (folio_index(folio) != index) {
+ xas_reset(xas);
+ break;
+ }
+
+ if (!folio_try_get_rcu(folio)) {
+ xas_reset(xas);
+ continue;
+ }
+
+ /* Has the folio moved or been split? */
+ if (unlikely(folio != xas_reload(xas))) {
+ folio_put(folio);
+ xas_reset(xas);
+ break;
+ }
+
+ if (!folio_trylock(folio)) {
+ folio_put(folio);
+ xas_reset(xas);
+ break;
+ }
+ if (!folio_test_dirty(folio) ||
+ folio_test_writeback(folio) ||
+ folio_test_fscache(folio)) {
+ folio_unlock(folio);
+ folio_put(folio);
+ xas_reset(xas);
+ break;
+ }
+
+ stop = false;
+ len = folio_size(folio);
+ priv = folio_get_private(folio);
+ if ((const struct netfs_group *)priv != group) {
+ stop = true;
+ finfo = netfs_folio_info(folio);
+ if (finfo->netfs_group != group ||
+ finfo->dirty_offset > 0) {
+ folio_unlock(folio);
+ folio_put(folio);
+ xas_reset(xas);
+ break;
+ }
+ len = finfo->dirty_len;
+ }
+
+ *_top += folio_size(folio);
+ index += folio_nr_pages(folio);
+ *_count -= folio_nr_pages(folio);
+ *_len += len;
+ if (*_len >= max_len || *_count <= 0)
+ stop = true;
+
+ if (!folio_batch_add(&fbatch, folio))
+ break;
+ if (stop)
+ break;
+ }
+
+ xas_pause(xas);
+ rcu_read_unlock();
+
+ /* Now, if we obtained any folios, we can shift them to being
+ * writable and mark them for caching.
+ */
+ if (!folio_batch_count(&fbatch))
+ break;
+
+ for (i = 0; i < folio_batch_count(&fbatch); i++) {
+ folio = fbatch.folios[i];
+ trace_netfs_folio(folio, netfs_folio_trace_store_plus);
+
+ if (!folio_clear_dirty_for_io(folio))
+ BUG();
+ folio_start_writeback(folio);
+ netfs_folio_start_fscache(caching, folio);
+ folio_unlock(folio);
+ }
+
+ folio_batch_release(&fbatch);
+ cond_resched();
+ } while (!stop);
+}
+
+/*
+ * Synchronously write back the locked page and any subsequent non-locked dirty
+ * pages.
+ */
+static ssize_t netfs_write_back_from_locked_folio(struct address_space *mapping,
+ struct writeback_control *wbc,
+ struct netfs_group *group,
+ struct xa_state *xas,
+ struct folio *folio,
+ unsigned long long start,
+ unsigned long long end)
+{
+ struct netfs_io_request *wreq;
+ struct netfs_folio *finfo;
+ struct netfs_inode *ctx = netfs_inode(mapping->host);
+ unsigned long long i_size = i_size_read(&ctx->inode);
+ size_t len, max_len;
+ bool caching = netfs_is_cache_enabled(ctx);
+ long count = wbc->nr_to_write;
+ int ret;
+
+ _enter(",%lx,%llx-%llx,%u", folio_index(folio), start, end, caching);
+
+ wreq = netfs_alloc_request(mapping, NULL, start, folio_size(folio),
+ NETFS_WRITEBACK);
+ if (IS_ERR(wreq)) {
+ folio_unlock(folio);
+ return PTR_ERR(wreq);
+ }
+
+ if (!folio_clear_dirty_for_io(folio))
+ BUG();
+ folio_start_writeback(folio);
+ netfs_folio_start_fscache(caching, folio);
+
+ count -= folio_nr_pages(folio);
+
+ /* Find all consecutive lockable dirty pages that have contiguous
+ * written regions, stopping when we find a page that is not
+ * immediately lockable, is not dirty or is missing, or we reach the
+ * end of the range.
+ */
+ trace_netfs_folio(folio, netfs_folio_trace_store);
+
+ len = wreq->len;
+ finfo = netfs_folio_info(folio);
+ if (finfo) {
+ start += finfo->dirty_offset;
+ if (finfo->dirty_offset + finfo->dirty_len != len) {
+ len = finfo->dirty_len;
+ goto cant_expand;
+ }
+ len = finfo->dirty_len;
+ }
+
+ if (start < i_size) {
+ /* Trim the write to the EOF; the extra data is ignored. Also
+ * put an upper limit on the size of a single storedata op.
+ */
+ max_len = 65536 * 4096;
+ max_len = min_t(unsigned long long, max_len, end - start + 1);
+ max_len = min_t(unsigned long long, max_len, i_size - start);
+
+ if (len < max_len)
+ netfs_extend_writeback(mapping, group, xas, &count, start,
+ max_len, caching, &len, &wreq->upper_len);
+ }
+
+cant_expand:
+ len = min_t(unsigned long long, len, i_size - start);
+
+ /* We now have a contiguous set of dirty pages, each with writeback
+ * set; the first page is still locked at this point, but all the rest
+ * have been unlocked.
+ */
+ folio_unlock(folio);
+ wreq->start = start;
+ wreq->len = len;
+
+ if (start < i_size) {
+ _debug("write back %zx @%llx [%llx]", len, start, i_size);
+
+ /* Speculatively write to the cache. We have to fix this up
+ * later if the store fails.
+ */
+ wreq->cleanup = netfs_cleanup_buffered_write;
+
+ iov_iter_xarray(&wreq->iter, ITER_SOURCE, &mapping->i_pages, start,
+ wreq->upper_len);
+ __set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags);
+ ret = netfs_begin_write(wreq, true, netfs_write_trace_writeback);
+ if (ret == 0 || ret == -EIOCBQUEUED)
+ wbc->nr_to_write -= len / PAGE_SIZE;
+ } else {
+ _debug("write discard %zx @%llx [%llx]", len, start, i_size);
+
+ /* The dirty region was entirely beyond the EOF. */
+ fscache_clear_page_bits(mapping, start, len, caching);
+ netfs_pages_written_back(wreq);
+ ret = 0;
+ }
+
+ netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
+ _leave(" = 1");
+ return 1;
+}
+
+/*
+ * Write a region of pages back to the server
+ */
+static ssize_t netfs_writepages_begin(struct address_space *mapping,
+ struct writeback_control *wbc,
+ struct netfs_group *group,
+ struct xa_state *xas,
+ unsigned long long *_start,
+ unsigned long long end)
+{
+ const struct netfs_folio *finfo;
+ struct folio *folio;
+ unsigned long long start = *_start;
+ ssize_t ret;
+ void *priv;
+ int skips = 0;
+
+ _enter("%llx,%llx,", start, end);
+
+search_again:
+ /* Find the first dirty page in the group. */
+ rcu_read_lock();
+
+ for (;;) {
+ folio = xas_find_marked(xas, end / PAGE_SIZE, PAGECACHE_TAG_DIRTY);
+ if (xas_retry(xas, folio) || xa_is_value(folio))
+ continue;
+ if (!folio)
+ break;
+
+ if (!folio_try_get_rcu(folio)) {
+ xas_reset(xas);
+ continue;
+ }
+
+ if (unlikely(folio != xas_reload(xas))) {
+ folio_put(folio);
+ xas_reset(xas);
+ continue;
+ }
+
+ /* Skip any dirty folio that's not in the group of interest. */
+ priv = folio_get_private(folio);
+ if ((const struct netfs_group *)priv != group) {
+ finfo = netfs_folio_info(folio);
+ if (finfo->netfs_group != group) {
+ folio_put(folio);
+ continue;
+ }
+ }
+
+ xas_pause(xas);
+ break;
+ }
+ rcu_read_unlock();
+ if (!folio)
+ return 0;
+
+ start = folio_pos(folio); /* May regress with THPs */
+
+ _debug("wback %lx", folio_index(folio));
+
+ /* At this point we hold neither the i_pages lock nor the page lock:
+ * the page may be truncated or invalidated (changing page->mapping to
+ * NULL), or even swizzled back from swapper_space to tmpfs file
+ * mapping
+ */
+lock_again:
+ if (wbc->sync_mode != WB_SYNC_NONE) {
+ ret = folio_lock_killable(folio);
+ if (ret < 0)
+ return ret;
+ } else {
+ if (!folio_trylock(folio))
+ goto search_again;
+ }
+
+ if (folio->mapping != mapping ||
+ !folio_test_dirty(folio)) {
+ start += folio_size(folio);
+ folio_unlock(folio);
+ goto search_again;
+ }
+
+ if (folio_test_writeback(folio) ||
+ folio_test_fscache(folio)) {
+ folio_unlock(folio);
+ if (wbc->sync_mode != WB_SYNC_NONE) {
+ folio_wait_writeback(folio);
+#ifdef CONFIG_NETFS_FSCACHE
+ folio_wait_fscache(folio);
+#endif
+ goto lock_again;
+ }
+
+ start += folio_size(folio);
+ if (wbc->sync_mode == WB_SYNC_NONE) {
+ if (skips >= 5 || need_resched()) {
+ ret = 0;
+ goto out;
+ }
+ skips++;
+ }
+ goto search_again;
+ }
+
+ ret = netfs_write_back_from_locked_folio(mapping, wbc, group, xas,
+ folio, start, end);
+out:
+ if (ret > 0)
+ *_start = start + ret;
+ _leave(" = %zd [%llx]", ret, *_start);
+ return ret;
+}
+
+/*
+ * Write a region of pages back to the server
+ */
+static int netfs_writepages_region(struct address_space *mapping,
+ struct writeback_control *wbc,
+ struct netfs_group *group,
+ unsigned long long *_start,
+ unsigned long long end)
+{
+ ssize_t ret;
+
+ XA_STATE(xas, &mapping->i_pages, *_start / PAGE_SIZE);
+
+ do {
+ ret = netfs_writepages_begin(mapping, wbc, group, &xas,
+ _start, end);
+ if (ret > 0 && wbc->nr_to_write > 0)
+ cond_resched();
+ } while (ret > 0 && wbc->nr_to_write > 0);
+
+ return ret > 0 ? 0 : ret;
+}
+
+/*
+ * write some of the pending data back to the server
+ */
+int netfs_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct netfs_group *group = NULL;
+ loff_t start, end;
+ int ret;
+
+ _enter("");
+
+ /* We have to be careful as we can end up racing with setattr()
+ * truncating the pagecache since the caller doesn't take a lock here
+ * to prevent it.
+ */
+
+ if (wbc->range_cyclic && mapping->writeback_index) {
+ start = mapping->writeback_index * PAGE_SIZE;
+ ret = netfs_writepages_region(mapping, wbc, group,
+ &start, LLONG_MAX);
+ if (ret < 0)
+ goto out;
+
+ if (wbc->nr_to_write <= 0) {
+ mapping->writeback_index = start / PAGE_SIZE;
+ goto out;
+ }
+
+ start = 0;
+ end = mapping->writeback_index * PAGE_SIZE;
+ mapping->writeback_index = 0;
+ ret = netfs_writepages_region(mapping, wbc, group, &start, end);
+ if (ret == 0)
+ mapping->writeback_index = start / PAGE_SIZE;
+ } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
+ start = 0;
+ ret = netfs_writepages_region(mapping, wbc, group,
+ &start, LLONG_MAX);
+ if (wbc->nr_to_write > 0 && ret == 0)
+ mapping->writeback_index = start / PAGE_SIZE;
+ } else {
+ start = wbc->range_start;
+ ret = netfs_writepages_region(mapping, wbc, group,
+ &start, wbc->range_end);
+ }
+
+out:
+ _leave(" = %d", ret);
+ return ret;
+}
+EXPORT_SYMBOL(netfs_writepages);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 506c543f6888..71a70396c2f9 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -398,6 +398,8 @@ int netfs_read_folio(struct file *, struct folio *);
int netfs_write_begin(struct netfs_inode *, struct file *,
struct address_space *, loff_t pos, unsigned int len,
struct folio **, void **fsdata);
+int netfs_writepages(struct address_space *mapping,
+ struct writeback_control *wbc);
bool netfs_dirty_folio(struct address_space *mapping, struct folio *folio);
int netfs_unpin_writeback(struct inode *inode, struct writeback_control *wbc);
void netfs_clear_inode_writeback(struct inode *inode, const void *aux);
Provide a flag whereby a filesystem may request that cifs_perform_write()
perform write-through caching. This involves putting pages directly into
writeback rather than dirty and attaching them to a write operation as we
go.
Further, the writes being made are limited to the byte range being written
rather than whole folios being written. This can be used by cifs, for
example, to deal with strict byte-range locking.
This can't be used with content encryption as that may require expansion of
the write RPC beyond the write being made.
This doesn't affect writes via mmap - those are written back in the normal
way; similarly failed writethrough writes are marked dirty and left to
writeback to retry. Another option would be to simply invalidate them, but
the contents can be simultaneously accessed by read() and through mmap.
Signed-off-by: David Howells <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/buffered_write.c | 69 +++++++++++++++++++++++----
fs/netfs/internal.h | 3 ++
fs/netfs/main.c | 1 +
fs/netfs/objects.c | 1 +
fs/netfs/output.c | 90 ++++++++++++++++++++++++++++++++++++
include/linux/netfs.h | 2 +
include/trace/events/netfs.h | 8 +++-
7 files changed, 162 insertions(+), 12 deletions(-)
diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 50be8fe3ca43..6ca6c4bde5eb 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -26,6 +26,8 @@ enum netfs_how_to_modify {
NETFS_FLUSH_CONTENT, /* Flush incompatible content. */
};
+static void netfs_cleanup_buffered_write(struct netfs_io_request *wreq);
+
static void netfs_set_group(struct folio *folio, struct netfs_group *netfs_group)
{
if (netfs_group && !folio_get_private(folio))
@@ -133,6 +135,14 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
struct inode *inode = file_inode(file);
struct address_space *mapping = inode->i_mapping;
struct netfs_inode *ctx = netfs_inode(inode);
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_NONE,
+ .for_sync = true,
+ .nr_to_write = LONG_MAX,
+ .range_start = iocb->ki_pos,
+ .range_end = iocb->ki_pos + iter->count,
+ };
+ struct netfs_io_request *wreq = NULL;
struct netfs_folio *finfo;
struct folio *folio;
enum netfs_how_to_modify howto;
@@ -143,6 +153,30 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
size_t max_chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER;
bool maybe_trouble = false;
+ if (unlikely(test_bit(NETFS_ICTX_WRITETHROUGH, &ctx->flags) ||
+ iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC))
+ ) {
+ if (pos < i_size_read(inode)) {
+ ret = filemap_write_and_wait_range(mapping, pos, pos + iter->count);
+ if (ret < 0) {
+ goto out;
+ }
+ }
+
+ wbc_attach_fdatawrite_inode(&wbc, mapping->host);
+
+ wreq = netfs_begin_writethrough(iocb, iter->count);
+ if (IS_ERR(wreq)) {
+ wbc_detach_inode(&wbc);
+ ret = PTR_ERR(wreq);
+ wreq = NULL;
+ goto out;
+ }
+ if (!is_sync_kiocb(iocb))
+ wreq->iocb = iocb;
+ wreq->cleanup = netfs_cleanup_buffered_write;
+ }
+
do {
size_t flen;
size_t offset; /* Offset into pagecache folio */
@@ -315,7 +349,25 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
}
written += copied;
- folio_mark_dirty(folio);
+ if (likely(!wreq)) {
+ folio_mark_dirty(folio);
+ } else {
+ if (folio_test_dirty(folio))
+ /* Sigh. mmap. */
+ folio_clear_dirty_for_io(folio);
+ /* We make multiple writes to the folio... */
+ if (!folio_test_writeback(folio)) {
+ folio_wait_fscache(folio);
+ folio_start_writeback(folio);
+ folio_start_fscache(folio);
+ if (wreq->iter.count == 0)
+ trace_netfs_folio(folio, netfs_folio_trace_wthru);
+ else
+ trace_netfs_folio(folio, netfs_folio_trace_wthru_plus);
+ }
+ netfs_advance_writethrough(wreq, copied,
+ offset + copied == flen);
+ }
retry:
folio_unlock(folio);
folio_put(folio);
@@ -325,17 +377,14 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
} while (iov_iter_count(iter));
out:
- if (likely(written)) {
- /* Flush and wait for a write that requires immediate synchronisation. */
- if (iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC)) {
- _debug("dsync");
- ret = filemap_fdatawait_range(mapping, iocb->ki_pos,
- iocb->ki_pos + written);
- }
-
- iocb->ki_pos += written;
+ if (unlikely(wreq)) {
+ ret = netfs_end_writethrough(wreq, iocb);
+ wbc_detach_inode(&wbc);
+ if (ret == -EIOCBQUEUED)
+ return ret;
}
+ iocb->ki_pos += written;
_leave(" = %zd [%zd]", written, ret);
return written ? written : ret;
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 2de4f826dbe4..d2d63120ac60 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -101,6 +101,9 @@ static inline void netfs_see_request(struct netfs_io_request *rreq,
*/
int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
enum netfs_write_trace what);
+struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len);
+int netfs_advance_writethrough(struct netfs_io_request *wreq, size_t copied, bool to_page_end);
+int netfs_end_writethrough(struct netfs_io_request *wreq, struct kiocb *iocb);
/*
* stats.c
diff --git a/fs/netfs/main.c b/fs/netfs/main.c
index 473f889e1bd1..81a13071b258 100644
--- a/fs/netfs/main.c
+++ b/fs/netfs/main.c
@@ -30,6 +30,7 @@ static const char *netfs_origins[nr__netfs_io_origin] = {
[NETFS_READPAGE] = "RP",
[NETFS_READ_FOR_WRITE] = "RW",
[NETFS_WRITEBACK] = "WB",
+ [NETFS_WRITETHROUGH] = "WT",
[NETFS_LAUNDER_WRITE] = "LW",
[NETFS_UNBUFFERED_WRITE] = "UW",
[NETFS_DIO_READ] = "DR",
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index b4e3bd836e5d..610ceb5bd86c 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -41,6 +41,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
rreq->i_size = i_size_read(inode);
rreq->debug_id = atomic_inc_return(&debug_ids);
INIT_LIST_HEAD(&rreq->subrequests);
+ INIT_WORK(&rreq->work, NULL);
refcount_set(&rreq->ref, 1);
__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
diff --git a/fs/netfs/output.c b/fs/netfs/output.c
index cc9065733b42..625eb68f3e5a 100644
--- a/fs/netfs/output.c
+++ b/fs/netfs/output.c
@@ -386,3 +386,93 @@ int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
TASK_UNINTERRUPTIBLE);
return wreq->error;
}
+
+/*
+ * Begin a write operation for writing through the pagecache.
+ */
+struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len)
+{
+ struct netfs_io_request *wreq;
+ struct file *file = iocb->ki_filp;
+
+ wreq = netfs_alloc_request(file->f_mapping, file, iocb->ki_pos, len,
+ NETFS_WRITETHROUGH);
+ if (IS_ERR(wreq))
+ return wreq;
+
+ trace_netfs_write(wreq, netfs_write_trace_writethrough);
+
+ __set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags);
+ iov_iter_xarray(&wreq->iter, ITER_SOURCE, &wreq->mapping->i_pages, wreq->start, 0);
+ wreq->io_iter = wreq->iter;
+
+ /* ->outstanding > 0 carries a ref */
+ netfs_get_request(wreq, netfs_rreq_trace_get_for_outstanding);
+ atomic_set(&wreq->nr_outstanding, 1);
+ return wreq;
+}
+
+static void netfs_submit_writethrough(struct netfs_io_request *wreq, bool final)
+{
+ struct netfs_inode *ictx = netfs_inode(wreq->inode);
+ unsigned long long start;
+ size_t len;
+
+ if (!test_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags))
+ return;
+
+ start = wreq->start + wreq->submitted;
+ len = wreq->iter.count - wreq->submitted;
+ if (!final) {
+ len /= wreq->wsize; /* Round to number of maximum packets */
+ len *= wreq->wsize;
+ }
+
+ ictx->ops->create_write_requests(wreq, start, len);
+ wreq->submitted += len;
+}
+
+/*
+ * Advance the state of the write operation used when writing through the
+ * pagecache. Data has been copied into the pagecache that we need to append
+ * to the request. If we've added more than wsize then we need to create a new
+ * subrequest.
+ */
+int netfs_advance_writethrough(struct netfs_io_request *wreq, size_t copied, bool to_page_end)
+{
+ _enter("ic=%zu sb=%zu ws=%u cp=%zu tp=%u",
+ wreq->iter.count, wreq->submitted, wreq->wsize, copied, to_page_end);
+
+ wreq->iter.count += copied;
+ wreq->io_iter.count += copied;
+ if (to_page_end && wreq->io_iter.count - wreq->submitted >= wreq->wsize)
+ netfs_submit_writethrough(wreq, false);
+
+ return wreq->error;
+}
+
+/*
+ * End a write operation used when writing through the pagecache.
+ */
+int netfs_end_writethrough(struct netfs_io_request *wreq, struct kiocb *iocb)
+{
+ int ret = -EIOCBQUEUED;
+
+ _enter("ic=%zu sb=%zu ws=%u",
+ wreq->iter.count, wreq->submitted, wreq->wsize);
+
+ if (wreq->submitted < wreq->io_iter.count)
+ netfs_submit_writethrough(wreq, true);
+
+ if (atomic_dec_and_test(&wreq->nr_outstanding))
+ netfs_write_terminated(wreq, false);
+
+ if (is_sync_kiocb(iocb)) {
+ wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,
+ TASK_UNINTERRUPTIBLE);
+ ret = wreq->error;
+ }
+
+ netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
+ return ret;
+}
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 3413d06033ed..8cde618cf6d9 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -139,6 +139,7 @@ struct netfs_inode {
unsigned long flags;
#define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */
#define NETFS_ICTX_UNBUFFERED 1 /* I/O should not use the pagecache */
+#define NETFS_ICTX_WRITETHROUGH 2 /* Write-through caching */
};
/*
@@ -227,6 +228,7 @@ enum netfs_io_origin {
NETFS_READPAGE, /* This read is a synchronous read */
NETFS_READ_FOR_WRITE, /* This read is to prepare a write */
NETFS_WRITEBACK, /* This write was triggered by writepages */
+ NETFS_WRITETHROUGH, /* This write was made by netfs_perform_write() */
NETFS_LAUNDER_WRITE, /* This is triggered by ->launder_folio() */
NETFS_UNBUFFERED_WRITE, /* This is an unbuffered write */
NETFS_DIO_READ, /* This is a direct I/O read */
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index cc998798e20a..447a8c21cf57 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -27,13 +27,15 @@
EM(netfs_write_trace_dio_write, "DIO-WRITE") \
EM(netfs_write_trace_launder, "LAUNDER ") \
EM(netfs_write_trace_unbuffered_write, "UNB-WRITE") \
- E_(netfs_write_trace_writeback, "WRITEBACK")
+ EM(netfs_write_trace_writeback, "WRITEBACK") \
+ E_(netfs_write_trace_writethrough, "WRITETHRU")
#define netfs_rreq_origins \
EM(NETFS_READAHEAD, "RA") \
EM(NETFS_READPAGE, "RP") \
EM(NETFS_READ_FOR_WRITE, "RW") \
EM(NETFS_WRITEBACK, "WB") \
+ EM(NETFS_WRITETHROUGH, "WT") \
EM(NETFS_LAUNDER_WRITE, "LW") \
EM(NETFS_UNBUFFERED_WRITE, "UW") \
EM(NETFS_DIO_READ, "DR") \
@@ -136,7 +138,9 @@
EM(netfs_folio_trace_redirty, "redirty") \
EM(netfs_folio_trace_redirtied, "redirtied") \
EM(netfs_folio_trace_store, "store") \
- E_(netfs_folio_trace_store_plus, "store+")
+ EM(netfs_folio_trace_store_plus, "store+") \
+ EM(netfs_folio_trace_wthru, "wthru") \
+ E_(netfs_folio_trace_wthru_plus, "wthru+")
#ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
#define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
Track the file position above which the server is not expected to have any
data (the "zero point") and preemptively assume that we can satisfy
requests by filling them with zeroes locally rather than attempting to
download them if they're over that line - even if we've written data back
to the server. Assume that any data that was written back above that
position is held in the local cache. Note that we have to split requests
that straddle the line.
Make use of this to optimise away some reads from the server. We need to
set the zero point in the following circumstances:
(1) When we see an extant remote inode and have no cache for it, we set
the zero_point to i_size.
(2) On local inode creation, we set zero_point to 0.
(3) On local truncation down, we reduce zero_point to the new i_size if
the new i_size is lower.
(4) On local truncation up, we don't change zero_point.
(5) On local modification, we don't change zero_point.
(6) On remote invalidation, we set zero_point to the new i_size.
(7) If stored data is discarded from the pagecache or culled from fscache,
we must set zero_point above that if the data also got written to the
server.
(8) If dirty data is written back to the server, but not fscache, we must
set zero_point above that.
(9) If a direct I/O write is made, set zero_point above that.
Assuming the above, any read from the server at or above the zero_point
position will return all zeroes.
The zero_point value can be stored in the cache, provided the above rules
are applied to it by any code that culls part of the local cache.
Signed-off-by: David Howells <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/afs/inode.c | 22 +++++++++++++---------
fs/netfs/buffered_write.c | 2 +-
fs/netfs/direct_write.c | 4 ++++
fs/netfs/io.c | 10 ++++++++++
fs/netfs/misc.c | 5 +++++
fs/smb/client/cifsfs.c | 4 ++--
include/linux/netfs.h | 14 ++++++++++++--
7 files changed, 47 insertions(+), 14 deletions(-)
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 37485ae31471..2b44a342b4a1 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -168,6 +168,7 @@ static void afs_apply_status(struct afs_operation *op,
struct inode *inode = &vnode->netfs.inode;
struct timespec64 t;
umode_t mode;
+ bool unexpected_jump = false;
bool data_changed = false;
bool change_size = vp->set_size;
@@ -231,6 +232,7 @@ static void afs_apply_status(struct afs_operation *op,
}
change_size = true;
data_changed = true;
+ unexpected_jump = true;
} else if (vnode->status.type == AFS_FTYPE_DIR) {
/* Expected directory change is handled elsewhere so
* that we can locally edit the directory and save on a
@@ -252,6 +254,8 @@ static void afs_apply_status(struct afs_operation *op,
vnode->netfs.remote_i_size = status->size;
if (change_size || status->size > i_size_read(inode)) {
afs_set_i_size(vnode, status->size);
+ if (unexpected_jump)
+ vnode->netfs.zero_point = status->size;
inode_set_ctime_to_ts(inode, t);
inode_set_atime_to_ts(inode, t);
}
@@ -865,17 +869,17 @@ static void afs_setattr_success(struct afs_operation *op)
static void afs_setattr_edit_file(struct afs_operation *op)
{
struct afs_vnode_param *vp = &op->file[0];
- struct inode *inode = &vp->vnode->netfs.inode;
+ struct afs_vnode *vnode = vp->vnode;
if (op->setattr.attr->ia_valid & ATTR_SIZE) {
loff_t size = op->setattr.attr->ia_size;
loff_t i_size = op->setattr.old_i_size;
- if (size < i_size)
- truncate_pagecache(inode, size);
- if (size != i_size)
- fscache_resize_cookie(afs_vnode_cache(vp->vnode),
- vp->scb.status.size);
+ if (size != i_size) {
+ truncate_setsize(&vnode->netfs.inode, size);
+ netfs_resize_file(&vnode->netfs, size, true);
+ fscache_resize_cookie(afs_vnode_cache(vnode), size);
+ }
}
}
@@ -943,11 +947,11 @@ int afs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
*/
if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
attr->ia_size < i_size &&
- attr->ia_size > vnode->status.size) {
- truncate_pagecache(inode, attr->ia_size);
+ attr->ia_size > vnode->netfs.remote_i_size) {
+ truncate_setsize(inode, attr->ia_size);
+ netfs_resize_file(&vnode->netfs, size, false);
fscache_resize_cookie(afs_vnode_cache(vnode),
attr->ia_size);
- i_size_write(inode, attr->ia_size);
ret = 0;
goto out_unlock;
}
diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 6ca6c4bde5eb..08f28800232c 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -73,7 +73,7 @@ static enum netfs_how_to_modify netfs_how_to_modify(struct netfs_inode *ctx,
if (folio_test_uptodate(folio))
return NETFS_FOLIO_IS_UPTODATE;
- if (pos >= ctx->remote_i_size)
+ if (pos >= ctx->zero_point)
return NETFS_MODIFY_AND_CLEAR;
if (!maybe_trouble && offset == 0 && len >= flen)
diff --git a/fs/netfs/direct_write.c b/fs/netfs/direct_write.c
index bb0c2718f57b..aad05f2349a4 100644
--- a/fs/netfs/direct_write.c
+++ b/fs/netfs/direct_write.c
@@ -134,6 +134,7 @@ ssize_t netfs_unbuffered_write_iter(struct kiocb *iocb, struct iov_iter *from)
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
struct netfs_inode *ictx = netfs_inode(inode);
+ unsigned long long end;
ssize_t ret;
_enter("%llx,%zx,%llx", iocb->ki_pos, iov_iter_count(from), i_size_read(inode));
@@ -155,6 +156,9 @@ ssize_t netfs_unbuffered_write_iter(struct kiocb *iocb, struct iov_iter *from)
ret = kiocb_invalidate_pages(iocb, iov_iter_count(from));
if (ret < 0)
goto out;
+ end = iocb->ki_pos + iov_iter_count(from);
+ if (end > ictx->zero_point)
+ ictx->zero_point = end;
fscache_invalidate(netfs_i_cookie(ictx), NULL, i_size_read(inode),
FSCACHE_INVAL_DIO_WRITE);
diff --git a/fs/netfs/io.c b/fs/netfs/io.c
index 14c18be5aca0..5b5af96cd4b9 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -569,6 +569,7 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
struct iov_iter *io_iter)
{
enum netfs_io_source source = NETFS_DOWNLOAD_FROM_SERVER;
+ struct netfs_inode *ictx = netfs_inode(rreq->inode);
size_t lsize;
_enter("%llx-%llx,%llx", subreq->start, subreq->start + subreq->len, rreq->i_size);
@@ -586,6 +587,14 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
* to make serial calls, it can indicate a short read and then
* we will call it again.
*/
+ if (rreq->origin != NETFS_DIO_READ) {
+ if (subreq->start >= ictx->zero_point) {
+ source = NETFS_FILL_WITH_ZEROES;
+ goto set;
+ }
+ if (subreq->len > ictx->zero_point - subreq->start)
+ subreq->len = ictx->zero_point - subreq->start;
+ }
if (subreq->len > rreq->i_size - subreq->start)
subreq->len = rreq->i_size - subreq->start;
if (rreq->rsize && subreq->len > rreq->rsize)
@@ -607,6 +616,7 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
}
}
+set:
if (subreq->len > rreq->len)
pr_warn("R=%08x[%u] SREQ>RREQ %zx > %zx\n",
rreq->debug_id, subreq->debug_index,
diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c
index eeb44abe59c5..0e3af37fc924 100644
--- a/fs/netfs/misc.c
+++ b/fs/netfs/misc.c
@@ -240,6 +240,11 @@ EXPORT_SYMBOL(netfs_invalidate_folio);
bool netfs_release_folio(struct folio *folio, gfp_t gfp)
{
struct netfs_inode *ctx = netfs_inode(folio_inode(folio));
+ unsigned long long end;
+
+ end = folio_pos(folio) + folio_size(folio);
+ if (end > ctx->zero_point)
+ ctx->zero_point = end;
if (folio_test_private(folio))
return false;
diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index 96a65cf9b5ec..07cd88897c33 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -1220,7 +1220,7 @@ static int cifs_precopy_set_eof(struct inode *src_inode, struct cifsInodeInfo *s
if (rc < 0)
goto set_failed;
- netfs_resize_file(&src_cifsi->netfs, src_end);
+ netfs_resize_file(&src_cifsi->netfs, src_end, true);
fscache_resize_cookie(cifs_inode_cookie(src_inode), src_end);
return 0;
@@ -1351,7 +1351,7 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off,
smb_file_src, smb_file_target, off, len, destoff);
if (rc == 0 && new_size > i_size_read(target_inode)) {
truncate_setsize(target_inode, new_size);
- netfs_resize_file(&target_cifsi->netfs, new_size);
+ netfs_resize_file(&target_cifsi->netfs, new_size, true);
fscache_resize_cookie(cifs_inode_cookie(target_inode),
new_size);
}
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 8cde618cf6d9..a5374218efe4 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -136,6 +136,8 @@ struct netfs_inode {
struct fscache_cookie *cache;
#endif
loff_t remote_i_size; /* Size of the remote file */
+ loff_t zero_point; /* Size after which we assume there's no data
+ * on the server */
unsigned long flags;
#define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */
#define NETFS_ICTX_UNBUFFERED 1 /* I/O should not use the pagecache */
@@ -463,22 +465,30 @@ static inline void netfs_inode_init(struct netfs_inode *ctx,
{
ctx->ops = ops;
ctx->remote_i_size = i_size_read(&ctx->inode);
+ ctx->zero_point = ctx->remote_i_size;
ctx->flags = 0;
#if IS_ENABLED(CONFIG_FSCACHE)
ctx->cache = NULL;
#endif
+ /* ->releasepage() drives zero_point */
+ mapping_set_release_always(ctx->inode.i_mapping);
}
/**
* netfs_resize_file - Note that a file got resized
* @ctx: The netfs inode being resized
* @new_i_size: The new file size
+ * @changed_on_server: The change was applied to the server
*
* Inform the netfs lib that a file got resized so that it can adjust its state.
*/
-static inline void netfs_resize_file(struct netfs_inode *ctx, loff_t new_i_size)
+static inline void netfs_resize_file(struct netfs_inode *ctx, loff_t new_i_size,
+ bool changed_on_server)
{
- ctx->remote_i_size = new_i_size;
+ if (changed_on_server)
+ ctx->remote_i_size = new_i_size;
+ if (new_i_size < ctx->zero_point)
+ ctx->zero_point = new_i_size;
}
/**
Export the netfs_sreq tracepoint so that it can be called directly from
client filesystems/cache backend modules.
Signed-off-by: David Howells <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/netfs/main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/netfs/main.c b/fs/netfs/main.c
index 81a13071b258..5e77618a7940 100644
--- a/fs/netfs/main.c
+++ b/fs/netfs/main.c
@@ -17,6 +17,8 @@ MODULE_DESCRIPTION("Network fs support");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
+EXPORT_TRACEPOINT_SYMBOL(netfs_sreq);
+
unsigned netfs_debug;
module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask");
Implement support for unbuffered writes and direct I/O writes. If the
write is misaligned with respect to the fscrypt block size, then RMW cycles
are performed if necessary. DIO writes are a special case of unbuffered
writes with extra restriction imposed, such as block size alignment
requirements.
Also provide a field that can tell the code to add some extra space onto
the bounce buffer for use by the filesystem in the case of a
content-encrypted file.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/afs/inode.c | 2 +-
fs/netfs/Makefile | 1 +
fs/netfs/direct_write.c | 166 +++++++++++++++++++++++++++++++++++
fs/netfs/internal.h | 6 ++
fs/netfs/io.c | 2 +-
fs/netfs/main.c | 12 +--
fs/netfs/objects.c | 6 +-
fs/netfs/output.c | 30 +++++++
include/linux/netfs.h | 4 +
include/trace/events/netfs.h | 4 +-
mm/filemap.c | 1 +
11 files changed, 224 insertions(+), 10 deletions(-)
create mode 100644 fs/netfs/direct_write.c
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 6f375f0cf650..37485ae31471 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -250,7 +250,7 @@ static void afs_apply_status(struct afs_operation *op,
* what's on the server.
*/
vnode->netfs.remote_i_size = status->size;
- if (change_size) {
+ if (change_size || status->size > i_size_read(inode)) {
afs_set_i_size(vnode, status->size);
inode_set_ctime_to_ts(inode, t);
inode_set_atime_to_ts(inode, t);
diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile
index e968ab1eca40..d4d1d799819e 100644
--- a/fs/netfs/Makefile
+++ b/fs/netfs/Makefile
@@ -4,6 +4,7 @@ netfs-y := \
buffered_read.o \
buffered_write.o \
direct_read.o \
+ direct_write.o \
io.o \
iterator.o \
locking.o \
diff --git a/fs/netfs/direct_write.c b/fs/netfs/direct_write.c
new file mode 100644
index 000000000000..bb0c2718f57b
--- /dev/null
+++ b/fs/netfs/direct_write.c
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Unbuffered and direct write support.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells ([email protected])
+ */
+
+#include <linux/export.h>
+#include <linux/uio.h>
+#include "internal.h"
+
+static void netfs_cleanup_dio_write(struct netfs_io_request *wreq)
+{
+ struct inode *inode = wreq->inode;
+ unsigned long long end = wreq->start + wreq->len;
+
+ if (!wreq->error &&
+ i_size_read(inode) < end) {
+ if (wreq->netfs_ops->update_i_size)
+ wreq->netfs_ops->update_i_size(inode, end);
+ else
+ i_size_write(inode, end);
+ }
+}
+
+/*
+ * Perform an unbuffered write where we may have to do an RMW operation on an
+ * encrypted file. This can also be used for direct I/O writes.
+ */
+ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *iter,
+ struct netfs_group *netfs_group)
+{
+ struct netfs_io_request *wreq;
+ unsigned long long start = iocb->ki_pos;
+ unsigned long long end = start + iov_iter_count(iter);
+ ssize_t ret, n;
+ bool async = !is_sync_kiocb(iocb);
+
+ _enter("");
+
+ /* We're going to need a bounce buffer if what we transmit is going to
+ * be different in some way to the source buffer, e.g. because it gets
+ * encrypted/compressed or because it needs expanding to a block size.
+ */
+ // TODO
+
+ _debug("uw %llx-%llx", start, end);
+
+ wreq = netfs_alloc_request(iocb->ki_filp->f_mapping, iocb->ki_filp,
+ start, end - start,
+ iocb->ki_flags & IOCB_DIRECT ?
+ NETFS_DIO_WRITE : NETFS_UNBUFFERED_WRITE);
+ if (IS_ERR(wreq))
+ return PTR_ERR(wreq);
+
+ {
+ /* If this is an async op and we're not using a bounce buffer,
+ * we have to save the source buffer as the iterator is only
+ * good until we return. In such a case, extract an iterator
+ * to represent as much of the the output buffer as we can
+ * manage. Note that the extraction might not be able to
+ * allocate a sufficiently large bvec array and may shorten the
+ * request.
+ */
+ if (async || user_backed_iter(iter)) {
+ n = netfs_extract_user_iter(iter, wreq->len, &wreq->iter, 0);
+ if (n < 0) {
+ ret = n;
+ goto out;
+ }
+ wreq->direct_bv = (struct bio_vec *)wreq->iter.bvec;
+ wreq->direct_bv_count = n;
+ wreq->direct_bv_unpin = iov_iter_extract_will_pin(iter);
+ wreq->len = iov_iter_count(&wreq->iter);
+ } else {
+ wreq->iter = *iter;
+ }
+
+ wreq->io_iter = wreq->iter;
+ }
+
+ /* Copy the data into the bounce buffer and encrypt it. */
+ // TODO
+
+ /* Dispatch the write. */
+ __set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags);
+ if (async)
+ wreq->iocb = iocb;
+ wreq->cleanup = netfs_cleanup_dio_write;
+ ret = netfs_begin_write(wreq, is_sync_kiocb(iocb),
+ iocb->ki_flags & IOCB_DIRECT ?
+ netfs_write_trace_dio_write :
+ netfs_write_trace_unbuffered_write);
+ if (ret < 0) {
+ _debug("begin = %zd", ret);
+ goto out;
+ }
+
+ if (!async) {
+ trace_netfs_rreq(wreq, netfs_rreq_trace_wait_ip);
+ wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,
+ TASK_UNINTERRUPTIBLE);
+
+ ret = wreq->error;
+ _debug("waited = %zd", ret);
+ if (ret == 0) {
+ ret = wreq->transferred;
+ iocb->ki_pos += ret;
+ }
+ } else {
+ ret = -EIOCBQUEUED;
+ }
+
+out:
+ netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
+ return ret;
+}
+
+/**
+ * netfs_unbuffered_write_iter - Unbuffered write to a file
+ * @iocb: IO state structure
+ * @from: iov_iter with data to write
+ *
+ * Do an unbuffered write to a file, writing the data directly to the server
+ * and not lodging the data in the pagecache.
+ *
+ * Return:
+ * * Negative error code if no data has been written at all of
+ * vfs_fsync_range() failed for a synchronous write
+ * * Number of bytes written, even for truncated writes
+ */
+ssize_t netfs_unbuffered_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ struct netfs_inode *ictx = netfs_inode(inode);
+ ssize_t ret;
+
+ _enter("%llx,%zx,%llx", iocb->ki_pos, iov_iter_count(from), i_size_read(inode));
+
+ trace_netfs_write_iter(iocb, from);
+
+ ret = netfs_start_io_direct(inode);
+ if (ret < 0)
+ return ret;
+ ret = generic_write_checks(iocb, from);
+ if (ret < 0)
+ goto out;
+ ret = file_remove_privs(file);
+ if (ret < 0)
+ goto out;
+ ret = file_update_time(file);
+ if (ret < 0)
+ goto out;
+ ret = kiocb_invalidate_pages(iocb, iov_iter_count(from));
+ if (ret < 0)
+ goto out;
+
+ fscache_invalidate(netfs_i_cookie(ictx), NULL, i_size_read(inode),
+ FSCACHE_INVAL_DIO_WRITE);
+ ret = netfs_unbuffered_write_iter_locked(iocb, from, NULL);
+out:
+ netfs_end_io_direct(inode);
+ return ret;
+}
+EXPORT_SYMBOL(netfs_unbuffered_write_iter);
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 886c2e8f841f..2de4f826dbe4 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -26,6 +26,12 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq);
int netfs_prefetch_for_write(struct file *file, struct folio *folio,
size_t offset, size_t len);
+/*
+ * direct_write.c
+ */
+ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *iter,
+ struct netfs_group *netfs_group);
+
/*
* io.c
*/
diff --git a/fs/netfs/io.c b/fs/netfs/io.c
index c972415c8aad..01c7ff27228e 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -645,7 +645,7 @@ static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq,
subreq->debug_index = (*_debug_index)++;
subreq->start = rreq->start + rreq->submitted;
- subreq->len = rreq->len - rreq->submitted;
+ subreq->len = io_iter->count;
_debug("slice %llx,%zx,%zx", subreq->start, subreq->len, rreq->submitted);
list_add_tail(&subreq->rreq_link, &rreq->subrequests);
diff --git a/fs/netfs/main.c b/fs/netfs/main.c
index abb8857486ee..8e4db9ff40c4 100644
--- a/fs/netfs/main.c
+++ b/fs/netfs/main.c
@@ -26,11 +26,13 @@ LIST_HEAD(netfs_io_requests);
DEFINE_SPINLOCK(netfs_proc_lock);
static const char *netfs_origins[nr__netfs_io_origin] = {
- [NETFS_READAHEAD] = "RA",
- [NETFS_READPAGE] = "RP",
- [NETFS_READ_FOR_WRITE] = "RW",
- [NETFS_WRITEBACK] = "WB",
- [NETFS_DIO_READ] = "DR",
+ [NETFS_READAHEAD] = "RA",
+ [NETFS_READPAGE] = "RP",
+ [NETFS_READ_FOR_WRITE] = "RW",
+ [NETFS_WRITEBACK] = "WB",
+ [NETFS_UNBUFFERED_WRITE] = "UW",
+ [NETFS_DIO_READ] = "DR",
+ [NETFS_DIO_WRITE] = "DW",
};
/*
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index 7153f24e8034..93f1d7431199 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -20,8 +20,10 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
struct inode *inode = file ? file_inode(file) : mapping->host;
struct netfs_inode *ctx = netfs_inode(inode);
struct netfs_io_request *rreq;
- bool is_dio = (origin == NETFS_DIO_READ);
- bool cached = is_dio && netfs_is_cache_enabled(ctx);
+ bool is_unbuffered = (origin == NETFS_UNBUFFERED_WRITE ||
+ origin == NETFS_DIO_READ ||
+ origin == NETFS_DIO_WRITE);
+ bool cached = !is_unbuffered && netfs_is_cache_enabled(ctx);
int ret;
rreq = kzalloc(ctx->ops->io_request_size ?: sizeof(struct netfs_io_request),
diff --git a/fs/netfs/output.c b/fs/netfs/output.c
index 2ad0fd8c32be..560cbcea0c0a 100644
--- a/fs/netfs/output.c
+++ b/fs/netfs/output.c
@@ -74,11 +74,21 @@ static void netfs_write_terminated(struct netfs_io_request *wreq, bool was_async
{
struct netfs_io_subrequest *subreq;
struct netfs_inode *ctx = netfs_inode(wreq->inode);
+ size_t transferred = 0;
_enter("R=%x[]", wreq->debug_id);
trace_netfs_rreq(wreq, netfs_rreq_trace_write_done);
+ list_for_each_entry(subreq, &wreq->subrequests, rreq_link) {
+ if (subreq->error || subreq->transferred == 0)
+ break;
+ transferred += subreq->transferred;
+ if (subreq->transferred < subreq->len)
+ break;
+ }
+ wreq->transferred = transferred;
+
list_for_each_entry(subreq, &wreq->subrequests, rreq_link) {
if (!subreq->error)
continue;
@@ -110,11 +120,28 @@ static void netfs_write_terminated(struct netfs_io_request *wreq, bool was_async
wreq->cleanup(wreq);
+ if (wreq->origin == NETFS_DIO_WRITE &&
+ wreq->mapping->nrpages) {
+ pgoff_t first = wreq->start >> PAGE_SHIFT;
+ pgoff_t last = (wreq->start + wreq->transferred - 1) >> PAGE_SHIFT;
+ invalidate_inode_pages2_range(wreq->mapping, first, last);
+ }
+
+ if (wreq->origin == NETFS_DIO_WRITE)
+ inode_dio_end(wreq->inode);
+
_debug("finished");
trace_netfs_rreq(wreq, netfs_rreq_trace_wake_ip);
clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &wreq->flags);
wake_up_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS);
+ if (wreq->iocb) {
+ wreq->iocb->ki_pos += transferred;
+ if (wreq->iocb->ki_complete)
+ wreq->iocb->ki_complete(
+ wreq->iocb, wreq->error ? wreq->error : transferred);
+ }
+
netfs_clear_subrequests(wreq, was_async);
netfs_put_request(wreq, was_async, netfs_rreq_trace_put_complete);
}
@@ -329,6 +356,9 @@ int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
return -EIO;
}
+ if (wreq->origin == NETFS_DIO_WRITE)
+ inode_dio_begin(wreq->inode);
+
wreq->io_iter = wreq->iter;
/* ->outstanding > 0 carries a ref */
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 784afaff8c78..47efa8596527 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -138,6 +138,7 @@ struct netfs_inode {
loff_t remote_i_size; /* Size of the remote file */
unsigned long flags;
#define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */
+#define NETFS_ICTX_UNBUFFERED 1 /* I/O should not use the pagecache */
};
/*
@@ -226,7 +227,9 @@ enum netfs_io_origin {
NETFS_READPAGE, /* This read is a synchronous read */
NETFS_READ_FOR_WRITE, /* This read is to prepare a write */
NETFS_WRITEBACK, /* This write was triggered by writepages */
+ NETFS_UNBUFFERED_WRITE, /* This is an unbuffered write */
NETFS_DIO_READ, /* This is a direct I/O read */
+ NETFS_DIO_WRITE, /* This is a direct I/O write */
nr__netfs_io_origin
} __mode(byte);
@@ -380,6 +383,7 @@ ssize_t netfs_unbuffered_read_iter(struct kiocb *iocb, struct iov_iter *iter);
/* High-level write API */
ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
struct netfs_group *netfs_group);
+ssize_t netfs_unbuffered_write_iter(struct kiocb *iocb, struct iov_iter *from);
/* Address operations API */
struct readahead_control;
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index 5a4edadf0e59..914a24b03d08 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -33,7 +33,9 @@
EM(NETFS_READPAGE, "RP") \
EM(NETFS_READ_FOR_WRITE, "RW") \
EM(NETFS_WRITEBACK, "WB") \
- E_(NETFS_DIO_READ, "DR")
+ EM(NETFS_UNBUFFERED_WRITE, "UW") \
+ EM(NETFS_DIO_READ, "DR") \
+ E_(NETFS_DIO_WRITE, "DW")
#define netfs_rreq_traces \
EM(netfs_rreq_trace_assess, "ASSESS ") \
diff --git a/mm/filemap.c b/mm/filemap.c
index 1c5271ed0cc0..73626eb323f3 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2706,6 +2706,7 @@ int kiocb_invalidate_pages(struct kiocb *iocb, size_t count)
return invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT,
end >> PAGE_SHIFT);
}
+EXPORT_SYMBOL_GPL(kiocb_invalidate_pages);
/**
* generic_file_read_iter - generic filesystem read routine
Make afs use the netfs write helpers.
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
---
fs/afs/file.c | 70 +++-
fs/afs/internal.h | 10 +-
fs/afs/write.c | 707 ++-----------------------------------
include/trace/events/afs.h | 23 --
4 files changed, 84 insertions(+), 726 deletions(-)
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 3403bb792deb..833e7c2003e0 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -34,7 +34,7 @@ const struct file_operations afs_file_operations = {
.release = afs_release,
.llseek = generic_file_llseek,
.read_iter = afs_file_read_iter,
- .write_iter = afs_file_write,
+ .write_iter = netfs_file_write_iter,
.mmap = afs_file_mmap,
.splice_read = afs_file_splice_read,
.splice_write = iter_file_splice_write,
@@ -50,16 +50,15 @@ const struct inode_operations afs_file_inode_operations = {
};
const struct address_space_operations afs_file_aops = {
+ .direct_IO = noop_direct_IO,
.read_folio = netfs_read_folio,
.readahead = netfs_readahead,
.dirty_folio = netfs_dirty_folio,
- .launder_folio = afs_launder_folio,
+ .launder_folio = netfs_launder_folio,
.release_folio = netfs_release_folio,
.invalidate_folio = netfs_invalidate_folio,
- .write_begin = afs_write_begin,
- .write_end = afs_write_end,
- .writepages = afs_writepages,
.migrate_folio = filemap_migrate_folio,
+ .writepages = afs_writepages,
};
const struct address_space_operations afs_symlink_aops = {
@@ -355,7 +354,10 @@ static int afs_symlink_read_folio(struct file *file, struct folio *folio)
static int afs_init_request(struct netfs_io_request *rreq, struct file *file)
{
- rreq->netfs_priv = key_get(afs_file_key(file));
+ if (file)
+ rreq->netfs_priv = key_get(afs_file_key(file));
+ rreq->rsize = 256 * 1024;
+ rreq->wsize = 256 * 1024;
return 0;
}
@@ -372,11 +374,36 @@ static void afs_free_request(struct netfs_io_request *rreq)
key_put(rreq->netfs_priv);
}
+static void afs_update_i_size(struct inode *inode, loff_t new_i_size)
+{
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ loff_t i_size;
+
+ write_seqlock(&vnode->cb_lock);
+ i_size = i_size_read(&vnode->netfs.inode);
+ if (new_i_size > i_size) {
+ i_size_write(&vnode->netfs.inode, new_i_size);
+ inode_set_bytes(&vnode->netfs.inode, new_i_size);
+ }
+ write_sequnlock(&vnode->cb_lock);
+ fscache_update_cookie(afs_vnode_cache(vnode), NULL, &new_i_size);
+}
+
+static void afs_netfs_invalidate_cache(struct netfs_io_request *wreq)
+{
+ struct afs_vnode *vnode = AFS_FS_I(wreq->inode);
+
+ afs_invalidate_cache(vnode, 0);
+}
+
const struct netfs_request_ops afs_req_ops = {
.init_request = afs_init_request,
.free_request = afs_free_request,
.check_write_begin = afs_check_write_begin,
.issue_read = afs_issue_read,
+ .update_i_size = afs_update_i_size,
+ .invalidate_cache = afs_netfs_invalidate_cache,
+ .create_write_requests = afs_create_write_requests,
};
static void afs_add_open_mmap(struct afs_vnode *vnode)
@@ -445,28 +472,39 @@ static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pg
static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
{
- struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct afs_vnode *vnode = AFS_FS_I(inode);
struct afs_file *af = iocb->ki_filp->private_data;
- int ret;
+ ssize_t ret;
- ret = afs_validate(vnode, af->key);
+ if (iocb->ki_flags & IOCB_DIRECT)
+ return netfs_unbuffered_read_iter(iocb, iter);
+
+ ret = netfs_start_io_read(inode);
if (ret < 0)
return ret;
-
- return generic_file_read_iter(iocb, iter);
+ ret = afs_validate(vnode, af->key);
+ if (ret == 0)
+ ret = filemap_read(iocb, iter, 0);
+ netfs_end_io_read(inode);
+ return ret;
}
static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe,
size_t len, unsigned int flags)
{
- struct afs_vnode *vnode = AFS_FS_I(file_inode(in));
+ struct inode *inode = file_inode(in);
+ struct afs_vnode *vnode = AFS_FS_I(inode);
struct afs_file *af = in->private_data;
- int ret;
+ ssize_t ret;
- ret = afs_validate(vnode, af->key);
+ ret = netfs_start_io_read(inode);
if (ret < 0)
return ret;
-
- return filemap_splice_read(in, ppos, pipe, len, flags);
+ ret = afs_validate(vnode, af->key);
+ if (ret == 0)
+ ret = filemap_splice_read(in, ppos, pipe, len, flags);
+ netfs_end_io_read(inode);
+ return ret;
}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index b60fc1067381..197d456dc07e 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -1463,19 +1463,11 @@ extern int afs_check_volume_status(struct afs_volume *, struct afs_operation *);
/*
* write.c
*/
-extern int afs_write_begin(struct file *file, struct address_space *mapping,
- loff_t pos, unsigned len,
- struct page **pagep, void **fsdata);
-extern int afs_write_end(struct file *file, struct address_space *mapping,
- loff_t pos, unsigned len, unsigned copied,
- struct page *page, void *fsdata);
-extern int afs_writepage(struct page *, struct writeback_control *);
extern int afs_writepages(struct address_space *, struct writeback_control *);
-extern ssize_t afs_file_write(struct kiocb *, struct iov_iter *);
extern int afs_fsync(struct file *, loff_t, loff_t, int);
extern vm_fault_t afs_page_mkwrite(struct vm_fault *vmf);
extern void afs_prune_wb_keys(struct afs_vnode *);
-int afs_launder_folio(struct folio *);
+void afs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size_t len);
/*
* xattr.c
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 80daf28d8f8b..09b6c0b9a28e 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -12,228 +12,17 @@
#include <linux/writeback.h>
#include <linux/pagevec.h>
#include <linux/netfs.h>
+#include <trace/events/netfs.h>
#include "internal.h"
-static int afs_writepages_region(struct address_space *mapping,
- struct writeback_control *wbc,
- unsigned long long start,
- unsigned long long end, loff_t *_next,
- bool max_one_loop);
-
-static void afs_write_to_cache(struct afs_vnode *vnode, loff_t start, size_t len,
- loff_t i_size, bool caching);
-
-#ifdef CONFIG_AFS_FSCACHE
-static void afs_folio_start_fscache(bool caching, struct folio *folio)
-{
- if (caching)
- folio_start_fscache(folio);
-}
-#else
-static void afs_folio_start_fscache(bool caching, struct folio *folio)
-{
-}
-#endif
-
-/*
- * prepare to perform part of a write to a page
- */
-int afs_write_begin(struct file *file, struct address_space *mapping,
- loff_t pos, unsigned len,
- struct page **_page, void **fsdata)
-{
- struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
- struct folio *folio;
- int ret;
-
- _enter("{%llx:%llu},%llx,%x",
- vnode->fid.vid, vnode->fid.vnode, pos, len);
-
- /* Prefetch area to be written into the cache if we're caching this
- * file. We need to do this before we get a lock on the page in case
- * there's more than one writer competing for the same cache block.
- */
- ret = netfs_write_begin(&vnode->netfs, file, mapping, pos, len, &folio, fsdata);
- if (ret < 0)
- return ret;
-
-try_again:
- /* See if this page is already partially written in a way that we can
- * merge the new write with.
- */
- if (folio_test_writeback(folio)) {
- trace_afs_folio_dirty(vnode, tracepoint_string("alrdy"), folio);
- folio_unlock(folio);
- goto wait_for_writeback;
- }
-
- *_page = folio_file_page(folio, pos / PAGE_SIZE);
- _leave(" = 0");
- return 0;
-
-wait_for_writeback:
- ret = folio_wait_writeback_killable(folio);
- if (ret < 0)
- goto error;
-
- ret = folio_lock_killable(folio);
- if (ret < 0)
- goto error;
- goto try_again;
-
-error:
- folio_put(folio);
- _leave(" = %d", ret);
- return ret;
-}
-
-/*
- * finalise part of a write to a page
- */
-int afs_write_end(struct file *file, struct address_space *mapping,
- loff_t pos, unsigned len, unsigned copied,
- struct page *subpage, void *fsdata)
-{
- struct folio *folio = page_folio(subpage);
- struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
- loff_t i_size, write_end_pos;
-
- _enter("{%llx:%llu},{%lx}",
- vnode->fid.vid, vnode->fid.vnode, folio_index(folio));
-
- if (!folio_test_uptodate(folio)) {
- if (copied < len) {
- copied = 0;
- goto out;
- }
-
- folio_mark_uptodate(folio);
- }
-
- if (copied == 0)
- goto out;
-
- write_end_pos = pos + copied;
-
- i_size = i_size_read(&vnode->netfs.inode);
- if (write_end_pos > i_size) {
- write_seqlock(&vnode->cb_lock);
- i_size = i_size_read(&vnode->netfs.inode);
- if (write_end_pos > i_size)
- afs_set_i_size(vnode, write_end_pos);
- write_sequnlock(&vnode->cb_lock);
- fscache_update_cookie(afs_vnode_cache(vnode), NULL, &write_end_pos);
- }
-
- if (folio_mark_dirty(folio))
- _debug("dirtied %lx", folio_index(folio));
-
-out:
- folio_unlock(folio);
- folio_put(folio);
- return copied;
-}
-
-/*
- * kill all the pages in the given range
- */
-static void afs_kill_pages(struct address_space *mapping,
- loff_t start, loff_t len)
-{
- struct afs_vnode *vnode = AFS_FS_I(mapping->host);
- struct folio *folio;
- pgoff_t index = start / PAGE_SIZE;
- pgoff_t last = (start + len - 1) / PAGE_SIZE, next;
-
- _enter("{%llx:%llu},%llx @%llx",
- vnode->fid.vid, vnode->fid.vnode, len, start);
-
- do {
- _debug("kill %lx (to %lx)", index, last);
-
- folio = filemap_get_folio(mapping, index);
- if (IS_ERR(folio)) {
- next = index + 1;
- continue;
- }
-
- next = folio_next_index(folio);
-
- folio_clear_uptodate(folio);
- folio_end_writeback(folio);
- folio_lock(folio);
- generic_error_remove_page(mapping, &folio->page);
- folio_unlock(folio);
- folio_put(folio);
-
- } while (index = next, index <= last);
-
- _leave("");
-}
-
-/*
- * Redirty all the pages in a given range.
- */
-static void afs_redirty_pages(struct writeback_control *wbc,
- struct address_space *mapping,
- loff_t start, loff_t len)
-{
- struct afs_vnode *vnode = AFS_FS_I(mapping->host);
- struct folio *folio;
- pgoff_t index = start / PAGE_SIZE;
- pgoff_t last = (start + len - 1) / PAGE_SIZE, next;
-
- _enter("{%llx:%llu},%llx @%llx",
- vnode->fid.vid, vnode->fid.vnode, len, start);
-
- do {
- _debug("redirty %llx @%llx", len, start);
-
- folio = filemap_get_folio(mapping, index);
- if (IS_ERR(folio)) {
- next = index + 1;
- continue;
- }
-
- next = index + folio_nr_pages(folio);
- folio_redirty_for_writepage(wbc, folio);
- folio_end_writeback(folio);
- folio_put(folio);
- } while (index = next, index <= last);
-
- _leave("");
-}
-
/*
* completion of write to server
*/
static void afs_pages_written_back(struct afs_vnode *vnode, loff_t start, unsigned int len)
{
- struct address_space *mapping = vnode->netfs.inode.i_mapping;
- struct folio *folio;
- pgoff_t end;
-
- XA_STATE(xas, &mapping->i_pages, start / PAGE_SIZE);
-
_enter("{%llx:%llu},{%x @%llx}",
vnode->fid.vid, vnode->fid.vnode, len, start);
- rcu_read_lock();
-
- end = (start + len - 1) / PAGE_SIZE;
- xas_for_each(&xas, folio, end) {
- if (!folio_test_writeback(folio)) {
- kdebug("bad %x @%llx page %lx %lx",
- len, start, folio_index(folio), end);
- ASSERT(folio_test_writeback(folio));
- }
-
- trace_afs_folio_dirty(vnode, tracepoint_string("clear"), folio);
- folio_end_writeback(folio);
- }
-
- rcu_read_unlock();
-
afs_prune_wb_keys(vnode);
_leave("");
}
@@ -370,339 +159,53 @@ static int afs_store_data(struct afs_vnode *vnode, struct iov_iter *iter, loff_t
return afs_put_operation(op);
}
-/*
- * Extend the region to be written back to include subsequent contiguously
- * dirty pages if possible, but don't sleep while doing so.
- *
- * If this page holds new content, then we can include filler zeros in the
- * writeback.
- */
-static void afs_extend_writeback(struct address_space *mapping,
- struct afs_vnode *vnode,
- long *_count,
- loff_t start,
- loff_t max_len,
- bool caching,
- size_t *_len)
+static void afs_upload_to_server(struct netfs_io_subrequest *subreq)
{
- struct folio_batch fbatch;
- struct folio *folio;
- pgoff_t index = (start + *_len) / PAGE_SIZE;
- bool stop = true;
- unsigned int i;
-
- XA_STATE(xas, &mapping->i_pages, index);
- folio_batch_init(&fbatch);
-
- do {
- /* Firstly, we gather up a batch of contiguous dirty pages
- * under the RCU read lock - but we can't clear the dirty flags
- * there if any of those pages are mapped.
- */
- rcu_read_lock();
-
- xas_for_each(&xas, folio, ULONG_MAX) {
- stop = true;
- if (xas_retry(&xas, folio))
- continue;
- if (xa_is_value(folio))
- break;
- if (folio_index(folio) != index)
- break;
-
- if (!folio_try_get_rcu(folio)) {
- xas_reset(&xas);
- continue;
- }
-
- /* Has the folio moved or been split? */
- if (unlikely(folio != xas_reload(&xas))) {
- folio_put(folio);
- break;
- }
-
- if (!folio_trylock(folio)) {
- folio_put(folio);
- break;
- }
- if (!folio_test_dirty(folio) ||
- folio_test_writeback(folio) ||
- folio_test_fscache(folio)) {
- folio_unlock(folio);
- folio_put(folio);
- break;
- }
-
- index += folio_nr_pages(folio);
- *_count -= folio_nr_pages(folio);
- *_len += folio_size(folio);
- stop = false;
- if (*_len >= max_len || *_count <= 0)
- stop = true;
-
- if (!folio_batch_add(&fbatch, folio))
- break;
- if (stop)
- break;
- }
-
- if (!stop)
- xas_pause(&xas);
- rcu_read_unlock();
-
- /* Now, if we obtained any folios, we can shift them to being
- * writable and mark them for caching.
- */
- if (!folio_batch_count(&fbatch))
- break;
-
- for (i = 0; i < folio_batch_count(&fbatch); i++) {
- folio = fbatch.folios[i];
- trace_afs_folio_dirty(vnode, tracepoint_string("store+"), folio);
+ struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);
+ ssize_t ret;
- if (!folio_clear_dirty_for_io(folio))
- BUG();
- if (folio_start_writeback(folio))
- BUG();
- afs_folio_start_fscache(caching, folio);
- folio_unlock(folio);
- }
+ _enter("%x[%x],%zx",
+ subreq->rreq->debug_id, subreq->debug_index, subreq->io_iter.count);
- folio_batch_release(&fbatch);
- cond_resched();
- } while (!stop);
+ trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
+ ret = afs_store_data(vnode, &subreq->io_iter, subreq->start,
+ subreq->rreq->origin == NETFS_LAUNDER_WRITE);
+ netfs_write_subrequest_terminated(subreq, ret < 0 ? ret : subreq->len,
+ false);
}
-/*
- * Synchronously write back the locked page and any subsequent non-locked dirty
- * pages.
- */
-static ssize_t afs_write_back_from_locked_folio(struct address_space *mapping,
- struct writeback_control *wbc,
- struct folio *folio,
- unsigned long long start,
- unsigned long long end)
+static void afs_upload_to_server_worker(struct work_struct *work)
{
- struct afs_vnode *vnode = AFS_FS_I(mapping->host);
- struct iov_iter iter;
- unsigned long long i_size = i_size_read(&vnode->netfs.inode);
- size_t len, max_len;
- bool caching = fscache_cookie_enabled(afs_vnode_cache(vnode));
- long count = wbc->nr_to_write;
- int ret;
-
- _enter(",%lx,%llx-%llx", folio_index(folio), start, end);
-
- if (folio_start_writeback(folio))
- BUG();
- afs_folio_start_fscache(caching, folio);
-
- count -= folio_nr_pages(folio);
-
- /* Find all consecutive lockable dirty pages that have contiguous
- * written regions, stopping when we find a page that is not
- * immediately lockable, is not dirty or is missing, or we reach the
- * end of the range.
- */
- trace_afs_folio_dirty(vnode, tracepoint_string("store"), folio);
-
- len = folio_size(folio);
- if (start < i_size) {
- /* Trim the write to the EOF; the extra data is ignored. Also
- * put an upper limit on the size of a single storedata op.
- */
- max_len = 65536 * 4096;
- max_len = min_t(unsigned long long, max_len, end - start + 1);
- max_len = min_t(unsigned long long, max_len, i_size - start);
-
- if (len < max_len)
- afs_extend_writeback(mapping, vnode, &count,
- start, max_len, caching, &len);
- len = min_t(unsigned long long, len, i_size - start);
- }
-
- /* We now have a contiguous set of dirty pages, each with writeback
- * set; the first page is still locked at this point, but all the rest
- * have been unlocked.
- */
- folio_unlock(folio);
-
- if (start < i_size) {
- _debug("write back %zx @%llx [%llx]", len, start, i_size);
-
- /* Speculatively write to the cache. We have to fix this up
- * later if the store fails.
- */
- afs_write_to_cache(vnode, start, len, i_size, caching);
-
- iov_iter_xarray(&iter, ITER_SOURCE, &mapping->i_pages, start, len);
- ret = afs_store_data(vnode, &iter, start, false);
- } else {
- _debug("write discard %zx @%llx [%llx]", len, start, i_size);
-
- /* The dirty region was entirely beyond the EOF. */
- fscache_clear_page_bits(mapping, start, len, caching);
- afs_pages_written_back(vnode, start, len);
- ret = 0;
- }
-
- switch (ret) {
- case 0:
- wbc->nr_to_write = count;
- ret = len;
- break;
-
- default:
- pr_notice("kAFS: Unexpected error from FS.StoreData %d\n", ret);
- fallthrough;
- case -EACCES:
- case -EPERM:
- case -ENOKEY:
- case -EKEYEXPIRED:
- case -EKEYREJECTED:
- case -EKEYREVOKED:
- case -ENETRESET:
- afs_redirty_pages(wbc, mapping, start, len);
- mapping_set_error(mapping, ret);
- break;
-
- case -EDQUOT:
- case -ENOSPC:
- afs_redirty_pages(wbc, mapping, start, len);
- mapping_set_error(mapping, -ENOSPC);
- break;
-
- case -EROFS:
- case -EIO:
- case -EREMOTEIO:
- case -EFBIG:
- case -ENOENT:
- case -ENOMEDIUM:
- case -ENXIO:
- trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail);
- afs_kill_pages(mapping, start, len);
- mapping_set_error(mapping, ret);
- break;
- }
+ struct netfs_io_subrequest *subreq =
+ container_of(work, struct netfs_io_subrequest, work);
- _leave(" = %d", ret);
- return ret;
+ afs_upload_to_server(subreq);
}
/*
- * write a region of pages back to the server
+ * Set up write requests for a writeback slice. We need to add a write request
+ * for each write we want to make.
*/
-static int afs_writepages_region(struct address_space *mapping,
- struct writeback_control *wbc,
- unsigned long long start,
- unsigned long long end, loff_t *_next,
- bool max_one_loop)
+void afs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size_t len)
{
- struct folio *folio;
- struct folio_batch fbatch;
- ssize_t ret;
- unsigned int i;
- int n, skips = 0;
-
- _enter("%llx,%llx,", start, end);
- folio_batch_init(&fbatch);
+ struct netfs_io_subrequest *subreq;
- do {
- pgoff_t index = start / PAGE_SIZE;
+ _enter("%x,%llx-%llx", wreq->debug_id, start, start + len);
- n = filemap_get_folios_tag(mapping, &index, end / PAGE_SIZE,
- PAGECACHE_TAG_DIRTY, &fbatch);
-
- if (!n)
- break;
- for (i = 0; i < n; i++) {
- folio = fbatch.folios[i];
- start = folio_pos(folio); /* May regress with THPs */
-
- _debug("wback %lx", folio_index(folio));
-
- /* At this point we hold neither the i_pages lock nor the
- * page lock: the page may be truncated or invalidated
- * (changing page->mapping to NULL), or even swizzled
- * back from swapper_space to tmpfs file mapping
- */
-try_again:
- if (wbc->sync_mode != WB_SYNC_NONE) {
- ret = folio_lock_killable(folio);
- if (ret < 0) {
- folio_batch_release(&fbatch);
- return ret;
- }
- } else {
- if (!folio_trylock(folio))
- continue;
- }
-
- if (folio->mapping != mapping ||
- !folio_test_dirty(folio)) {
- start += folio_size(folio);
- folio_unlock(folio);
- continue;
- }
-
- if (folio_test_writeback(folio) ||
- folio_test_fscache(folio)) {
- folio_unlock(folio);
- if (wbc->sync_mode != WB_SYNC_NONE) {
- folio_wait_writeback(folio);
-#ifdef CONFIG_AFS_FSCACHE
- folio_wait_fscache(folio);
-#endif
- goto try_again;
- }
-
- start += folio_size(folio);
- if (wbc->sync_mode == WB_SYNC_NONE) {
- if (skips >= 5 || need_resched()) {
- *_next = start;
- folio_batch_release(&fbatch);
- _leave(" = 0 [%llx]", *_next);
- return 0;
- }
- skips++;
- }
- continue;
- }
-
- if (!folio_clear_dirty_for_io(folio))
- BUG();
- ret = afs_write_back_from_locked_folio(mapping, wbc,
- folio, start, end);
- if (ret < 0) {
- _leave(" = %zd", ret);
- folio_batch_release(&fbatch);
- return ret;
- }
-
- start += ret;
- }
-
- folio_batch_release(&fbatch);
- cond_resched();
- } while (wbc->nr_to_write > 0);
-
- *_next = start;
- _leave(" = 0 [%llx]", *_next);
- return 0;
+ subreq = netfs_create_write_request(wreq, NETFS_UPLOAD_TO_SERVER,
+ start, len, afs_upload_to_server_worker);
+ if (subreq)
+ netfs_queue_write_request(subreq);
}
/*
* write some of the pending data back to the server
*/
-int afs_writepages(struct address_space *mapping,
- struct writeback_control *wbc)
+int afs_writepages(struct address_space *mapping, struct writeback_control *wbc)
{
struct afs_vnode *vnode = AFS_FS_I(mapping->host);
- loff_t start, next;
int ret;
- _enter("");
-
/* We have to be careful as we can end up racing with setattr()
* truncating the pagecache since the caller doesn't take a lock here
* to prevent it.
@@ -712,68 +215,11 @@ int afs_writepages(struct address_space *mapping,
else if (!down_read_trylock(&vnode->validate_lock))
return 0;
- if (wbc->range_cyclic) {
- start = mapping->writeback_index * PAGE_SIZE;
- ret = afs_writepages_region(mapping, wbc, start, LLONG_MAX,
- &next, false);
- if (ret == 0) {
- mapping->writeback_index = next / PAGE_SIZE;
- if (start > 0 && wbc->nr_to_write > 0) {
- ret = afs_writepages_region(mapping, wbc, 0,
- start, &next, false);
- if (ret == 0)
- mapping->writeback_index =
- next / PAGE_SIZE;
- }
- }
- } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
- ret = afs_writepages_region(mapping, wbc, 0, LLONG_MAX,
- &next, false);
- if (wbc->nr_to_write > 0 && ret == 0)
- mapping->writeback_index = next / PAGE_SIZE;
- } else {
- ret = afs_writepages_region(mapping, wbc,
- wbc->range_start, wbc->range_end,
- &next, false);
- }
-
+ ret = netfs_writepages(mapping, wbc);
up_read(&vnode->validate_lock);
- _leave(" = %d", ret);
return ret;
}
-/*
- * write to an AFS file
- */
-ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *from)
-{
- struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
- struct afs_file *af = iocb->ki_filp->private_data;
- ssize_t result;
- size_t count = iov_iter_count(from);
-
- _enter("{%llx:%llu},{%zu},",
- vnode->fid.vid, vnode->fid.vnode, count);
-
- if (IS_SWAPFILE(&vnode->netfs.inode)) {
- printk(KERN_INFO
- "AFS: Attempt to write to active swap file!\n");
- return -EBUSY;
- }
-
- if (!count)
- return 0;
-
- result = afs_validate(vnode, af->key);
- if (result < 0)
- return result;
-
- result = generic_file_write_iter(iocb, from);
-
- _leave(" = %zd", result);
- return result;
-}
-
/*
* flush any dirty pages for this process, and check for write errors.
* - the return status from this call provides a reliable indication of
@@ -802,49 +248,11 @@ int afs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
*/
vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
{
- struct folio *folio = page_folio(vmf->page);
struct file *file = vmf->vma->vm_file;
- struct inode *inode = file_inode(file);
- struct afs_vnode *vnode = AFS_FS_I(inode);
- struct afs_file *af = file->private_data;
- vm_fault_t ret = VM_FAULT_RETRY;
-
- _enter("{{%llx:%llu}},{%lx}", vnode->fid.vid, vnode->fid.vnode, folio_index(folio));
-
- afs_validate(vnode, af->key);
-
- sb_start_pagefault(inode->i_sb);
-
- /* Wait for the page to be written to the cache before we allow it to
- * be modified. We then assume the entire page will need writing back.
- */
-#ifdef CONFIG_AFS_FSCACHE
- if (folio_test_fscache(folio) &&
- folio_wait_fscache_killable(folio) < 0)
- goto out;
-#endif
-
- if (folio_wait_writeback_killable(folio))
- goto out;
-
- if (folio_lock_killable(folio) < 0)
- goto out;
-
- if (folio_wait_writeback_killable(folio) < 0) {
- folio_unlock(folio);
- goto out;
- }
-
- if (folio_test_dirty(folio))
- trace_afs_folio_dirty(vnode, tracepoint_string("mkwrite+"), folio);
- else
- trace_afs_folio_dirty(vnode, tracepoint_string("mkwrite"), folio);
- file_update_time(file);
- ret = VM_FAULT_LOCKED;
-out:
- sb_end_pagefault(inode->i_sb);
- return ret;
+ if (afs_validate(AFS_FS_I(file_inode(file)), afs_file_key(file)) < 0)
+ return VM_FAULT_SIGBUS;
+ return netfs_page_mkwrite(vmf, NULL);
}
/*
@@ -874,60 +282,3 @@ void afs_prune_wb_keys(struct afs_vnode *vnode)
afs_put_wb_key(wbk);
}
}
-
-/*
- * Clean up a page during invalidation.
- */
-int afs_launder_folio(struct folio *folio)
-{
- struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio));
- struct iov_iter iter;
- struct bio_vec bv;
- unsigned long long fend, i_size = vnode->netfs.inode.i_size;
- size_t len;
- int ret = 0;
-
- _enter("{%lx}", folio->index);
-
- if (folio_clear_dirty_for_io(folio) && folio_pos(folio) < i_size) {
- len = folio_size(folio);
- fend = folio_pos(folio) + len;
- if (vnode->netfs.inode.i_size < fend)
- len = fend - i_size;
-
- bvec_set_folio(&bv, folio, len, 0);
- iov_iter_bvec(&iter, WRITE, &bv, 1, len);
-
- trace_afs_folio_dirty(vnode, tracepoint_string("launder"), folio);
- ret = afs_store_data(vnode, &iter, folio_pos(folio), true);
- }
-
- trace_afs_folio_dirty(vnode, tracepoint_string("laundered"), folio);
- folio_wait_fscache(folio);
- return ret;
-}
-
-/*
- * Deal with the completion of writing the data to the cache.
- */
-static void afs_write_to_cache_done(void *priv, ssize_t transferred_or_error,
- bool was_async)
-{
- struct afs_vnode *vnode = priv;
-
- if (IS_ERR_VALUE(transferred_or_error) &&
- transferred_or_error != -ENOBUFS)
- afs_invalidate_cache(vnode, 0);
-}
-
-/*
- * Save the write to the cache also.
- */
-static void afs_write_to_cache(struct afs_vnode *vnode,
- loff_t start, size_t len, loff_t i_size,
- bool caching)
-{
- fscache_write_to_cache(afs_vnode_cache(vnode),
- vnode->netfs.inode.i_mapping, start, len, i_size,
- afs_write_to_cache_done, vnode, caching);
-}
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 08506680350c..754358149372 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -837,29 +837,6 @@ TRACE_EVENT(afs_dir_check_failed,
__entry->vnode, __entry->off, __entry->i_size)
);
-TRACE_EVENT(afs_folio_dirty,
- TP_PROTO(struct afs_vnode *vnode, const char *where, struct folio *folio),
-
- TP_ARGS(vnode, where, folio),
-
- TP_STRUCT__entry(
- __field(struct afs_vnode *, vnode)
- __field(const char *, where)
- __field(pgoff_t, index)
- __field(size_t, size)
- ),
-
- TP_fast_assign(
- __entry->vnode = vnode;
- __entry->where = where;
- __entry->index = folio_index(folio);
- __entry->size = folio_size(folio);
- ),
-
- TP_printk("vn=%p ix=%05lx s=%05lx %s",
- __entry->vnode, __entry->index, __entry->size, __entry->where)
- );
-
TRACE_EVENT(afs_call_state,
TP_PROTO(struct afs_call *call,
enum afs_call_state from,
Hi David,
On Thu, Dec 21, 2023 at 01:23:32PM +0000, David Howells wrote:
> Track the file position above which the server is not expected to have any
> data (the "zero point") and preemptively assume that we can satisfy
> requests by filling them with zeroes locally rather than attempting to
> download them if they're over that line - even if we've written data back
> to the server. Assume that any data that was written back above that
> position is held in the local cache. Note that we have to split requests
> that straddle the line.
>
> Make use of this to optimise away some reads from the server. We need to
> set the zero point in the following circumstances:
>
> (1) When we see an extant remote inode and have no cache for it, we set
> the zero_point to i_size.
>
> (2) On local inode creation, we set zero_point to 0.
>
> (3) On local truncation down, we reduce zero_point to the new i_size if
> the new i_size is lower.
>
> (4) On local truncation up, we don't change zero_point.
>
> (5) On local modification, we don't change zero_point.
>
> (6) On remote invalidation, we set zero_point to the new i_size.
>
> (7) If stored data is discarded from the pagecache or culled from fscache,
> we must set zero_point above that if the data also got written to the
> server.
>
> (8) If dirty data is written back to the server, but not fscache, we must
> set zero_point above that.
>
> (9) If a direct I/O write is made, set zero_point above that.
>
> Assuming the above, any read from the server at or above the zero_point
> position will return all zeroes.
>
> The zero_point value can be stored in the cache, provided the above rules
> are applied to it by any code that culls part of the local cache.
>
> Signed-off-by: David Howells <[email protected]>
> cc: Jeff Layton <[email protected]>
> cc: [email protected]
> cc: [email protected]
> cc: [email protected]
> ---
<snip>
> diff --git a/include/linux/netfs.h b/include/linux/netfs.h
> index 8cde618cf6d9..a5374218efe4 100644
> --- a/include/linux/netfs.h
> +++ b/include/linux/netfs.h
> @@ -136,6 +136,8 @@ struct netfs_inode {
> struct fscache_cookie *cache;
> #endif
> loff_t remote_i_size; /* Size of the remote file */
> + loff_t zero_point; /* Size after which we assume there's no data
> + * on the server */
> unsigned long flags;
> #define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */
> #define NETFS_ICTX_UNBUFFERED 1 /* I/O should not use the pagecache */
> @@ -463,22 +465,30 @@ static inline void netfs_inode_init(struct netfs_inode *ctx,
> {
> ctx->ops = ops;
> ctx->remote_i_size = i_size_read(&ctx->inode);
> + ctx->zero_point = ctx->remote_i_size;
> ctx->flags = 0;
> #if IS_ENABLED(CONFIG_FSCACHE)
> ctx->cache = NULL;
> #endif
> + /* ->releasepage() drives zero_point */
> + mapping_set_release_always(ctx->inode.i_mapping);
> }
I bisected a crash that I see when trying to mount an NFS volume to this
change as commit 6e3c8451f624 ("netfs: Optimise away reads above the
point at which there can be no data") in next-20231221:
[ 45.964963] BUG: kernel NULL pointer dereference, address: 0000000000000078
[ 45.964975] #PF: supervisor write access in kernel mode
[ 45.964982] #PF: error_code(0x0002) - not-present page
[ 45.964987] PGD 0 P4D 0
[ 45.964996] Oops: 0002 [#1] PREEMPT SMP NOPTI
[ 45.965004] CPU: 2 PID: 2419 Comm: mount.nfs Not tainted 6.7.0-rc6-next-20231221-debug-09925-g857647efa9be #1 adbbe7bc5037c662bc8f9b8e78ccf16be15b5e58
[ 45.965014] Hardware name: HP HP Desktop M01-F1xxx/87D6, BIOS F.12 12/17/2020
[ 45.965019] RIP: 0010:nfs_alloc_inode+0xa2/0xc0 [nfs]
[ 45.965092] Code: 80 b0 01 00 00 00 00 00 00 48 c7 80 38 04 00 00 00 f7 1e c2 48 c7 80 58 04 00 00 00 00 00 00 48 c7 80 40 04 00 00 00 00 00 00 <f0> 80 0a 80 48 05 b8 01 00 00 e9 5f 2b 20 f5 66 66 2e 0f 1f 84 00
[ 45.965099] RSP: 0018:ffffc900058f7bc0 EFLAGS: 00010286
[ 45.965107] RAX: ffff8881958c7290 RBX: ffff888168f0f800 RCX: 0000000000000000
[ 45.965112] RDX: 0000000000000078 RSI: ffffffffc2140a71 RDI: ffff88817a12b880
[ 45.965118] RBP: ffff888168f0f800 R08: ffffc900058f7b70 R09: 88728c958188ffff
[ 45.965123] R10: 000000000003a5c0 R11: 0000000000000005 R12: ffffffffc22f1a80
[ 45.965128] R13: ffffc900058f7c30 R14: 0000000000000000 R15: 0000000000000002
[ 45.965134] FS: 00007ff78c318740(0000) GS:ffff8887ff280000(0000) knlGS:0000000000000000
[ 45.965140] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 45.965146] CR2: 0000000000000078 CR3: 000000018a514000 CR4: 0000000000350ef0
[ 45.965152] Call Trace:
[ 45.965160] <TASK>
[ 45.965167] ? __die+0x23/0x70
[ 45.965183] ? page_fault_oops+0x173/0x4e0
[ 45.965197] ? nfs_alloc_inode+0x21/0xc0 [nfs aac4a012b174ef6e5996d0df3638a0616e82eb47]
[ 45.965279] ? exc_page_fault+0x7e/0x180
[ 45.965291] ? asm_exc_page_fault+0x26/0x30
[ 45.965308] ? nfs_alloc_inode+0x21/0xc0 [nfs aac4a012b174ef6e5996d0df3638a0616e82eb47]
[ 45.965374] ? nfs_alloc_inode+0xa2/0xc0 [nfs aac4a012b174ef6e5996d0df3638a0616e82eb47]
[ 45.965441] alloc_inode+0x1e/0xc0
[ 45.965452] ? __pfx_nfs_find_actor+0x10/0x10 [nfs aac4a012b174ef6e5996d0df3638a0616e82eb47]
[ 45.965517] iget5_locked+0x97/0xf0
[ 45.965525] ? __pfx_nfs_init_locked+0x10/0x10 [nfs aac4a012b174ef6e5996d0df3638a0616e82eb47]
[ 45.965593] nfs_fhget+0xe4/0x700 [nfs aac4a012b174ef6e5996d0df3638a0616e82eb47]
[ 45.965666] nfs_get_root+0xc6/0x4a0 [nfs aac4a012b174ef6e5996d0df3638a0616e82eb47]
[ 45.965732] ? kernfs_rename_ns+0x85/0x210
[ 45.965754] nfs_get_tree_common+0xc7/0x520 [nfs aac4a012b174ef6e5996d0df3638a0616e82eb47]
[ 45.965826] vfs_get_tree+0x29/0xf0
[ 45.965836] fc_mount+0x12/0x40
[ 45.965846] do_nfs4_mount+0x12e/0x370 [nfsv4 9bac1f2bd94d7294fbbaf875b7b5cec5adc527f5]
[ 45.965946] nfs4_try_get_tree+0x48/0xd0 [nfsv4 9bac1f2bd94d7294fbbaf875b7b5cec5adc527f5]
[ 45.966034] vfs_get_tree+0x29/0xf0
[ 45.966041] ? srso_return_thunk+0x5/0x5f
[ 45.966051] path_mount+0x4ca/0xb10
[ 45.966063] __x64_sys_mount+0x11a/0x150
[ 45.966074] do_syscall_64+0x64/0xe0
[ 45.966083] ? do_syscall_64+0x70/0xe0
[ 45.966090] ? syscall_exit_to_user_mode+0x2b/0x40
[ 45.966098] ? srso_return_thunk+0x5/0x5f
[ 45.966106] ? do_syscall_64+0x70/0xe0
[ 45.966113] ? srso_return_thunk+0x5/0x5f
[ 45.966121] ? exc_page_fault+0x7e/0x180
[ 45.966130] entry_SYSCALL_64_after_hwframe+0x6c/0x74
[ 45.966138] RIP: 0033:0x7ff78c5f2a1e
...
It appears that ctx->inode.i_mapping is NULL in netfs_inode_init(). This
patch appears to cure the problem for me but I am not sure if it is
proper or not.
Cheers,
Nathan
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index a5374218efe4..8daaba665421 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -471,7 +471,8 @@ static inline void netfs_inode_init(struct netfs_inode *ctx,
ctx->cache = NULL;
#endif
/* ->releasepage() drives zero_point */
- mapping_set_release_always(ctx->inode.i_mapping);
+ if (ctx->inode.i_mapping)
+ mapping_set_release_always(ctx->inode.i_mapping);
}
/**
Nathan Chancellor <[email protected]> wrote:
> It appears that ctx->inode.i_mapping is NULL in netfs_inode_init(). This
> patch appears to cure the problem for me but I am not sure if it is
> proper or not.
I'm not sure that's the best way. It kind of indicates that
nfs_netfs_inode_init() is not being called in the right place - it should
really be called after alloc_inode() has called inode_init_always().
However, mapping_set_release_always() makes ->release_folio() and
->invalidate_folio() always called for an inode's folios, even if PG_private
is not set - the idea being that this allows netfslib to update the
"zero_point" when a page we've written to the server gets invalidated here,
thereby requiring us to go fetch it again.
Now, NFS doesn't make use of this feature and fscache and cachefiles don't use
it directly, so we might not want to call mapping_set_release_always() for
NFS.
I'm not sure NFS can even reliably make use of it unless it's using a lease
unless it gets change notifications from the server.
So I'm thinking of applying your patch but add a comment to say why we're
doing it. A better way, though, is to move the call to nfs_netfs_inode_init()
and give it a flag to say whether or not we want the facility.
David
David Howells <[email protected]> wrote:
> A better way, though, is to move the call to nfs_netfs_inode_init()
> and give it a flag to say whether or not we want the facility.
Okay, I think I'll fold in the attached change.
David
---
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 55345753ae8d..b66466e97459 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -249,7 +249,7 @@ void v9fs_free_inode(struct inode *inode)
static void v9fs_set_netfs_context(struct inode *inode)
{
struct v9fs_inode *v9inode = V9FS_I(inode);
- netfs_inode_init(&v9inode->netfs, &v9fs_req_ops);
+ netfs_inode_init(&v9inode->netfs, &v9fs_req_ops, true);
}
int v9fs_init_inode(struct v9fs_session_info *v9ses,
diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c
index 1f656005018e..9c517269ff95 100644
--- a/fs/afs/dynroot.c
+++ b/fs/afs/dynroot.c
@@ -76,7 +76,7 @@ struct inode *afs_iget_pseudo_dir(struct super_block *sb, bool root)
/* there shouldn't be an existing inode */
BUG_ON(!(inode->i_state & I_NEW));
- netfs_inode_init(&vnode->netfs, NULL);
+ netfs_inode_init(&vnode->netfs, NULL, false);
inode->i_size = 0;
inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
if (root) {
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 2b44a342b4a1..381521e9e118 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -58,7 +58,7 @@ static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *paren
*/
static void afs_set_netfs_context(struct afs_vnode *vnode)
{
- netfs_inode_init(&vnode->netfs, &afs_req_ops);
+ netfs_inode_init(&vnode->netfs, &afs_req_ops, true);
}
/*
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 3149d79a9dbe..0c25d326afc4 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -574,7 +574,7 @@ struct inode *ceph_alloc_inode(struct super_block *sb)
doutc(fsc->client, "%p\n", &ci->netfs.inode);
/* Set parameters for the netfs library */
- netfs_inode_init(&ci->netfs, &ceph_netfs_ops);
+ netfs_inode_init(&ci->netfs, &ceph_netfs_ops, false);
spin_lock_init(&ci->i_ceph_lock);
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index 5407ab8c8783..e3cb4923316b 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -80,7 +80,7 @@ static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs)
}
static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi)
{
- netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops);
+ netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops, false);
}
extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr);
extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index a5374218efe4..06a03dd1aff1 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -456,22 +456,27 @@ static inline struct netfs_inode *netfs_inode(struct inode *inode)
* netfs_inode_init - Initialise a netfslib inode context
* @ctx: The netfs inode to initialise
* @ops: The netfs's operations list
+ * @use_zero_point: True to use the zero_point read optimisation
*
* Initialise the netfs library context struct. This is expected to follow on
* directly from the VFS inode struct.
*/
static inline void netfs_inode_init(struct netfs_inode *ctx,
- const struct netfs_request_ops *ops)
+ const struct netfs_request_ops *ops,
+ bool use_zero_point)
{
ctx->ops = ops;
ctx->remote_i_size = i_size_read(&ctx->inode);
- ctx->zero_point = ctx->remote_i_size;
+ ctx->zero_point = LLONG_MAX;
ctx->flags = 0;
#if IS_ENABLED(CONFIG_FSCACHE)
ctx->cache = NULL;
#endif
/* ->releasepage() drives zero_point */
- mapping_set_release_always(ctx->inode.i_mapping);
+ if (use_zero_point) {
+ ctx->zero_point = ctx->remote_i_size;
+ mapping_set_release_always(ctx->inode.i_mapping);
+ }
}
/**
This needs an additional change (see attached).
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index 1d318f85232d..1949763e66aa 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -114,7 +114,8 @@ config EROFS_FS_ZIP_DEFLATE
config EROFS_FS_ONDEMAND
bool "EROFS fscache-based on-demand read support"
- depends on CACHEFILES_ONDEMAND && (EROFS_FS=m && FSCACHE || EROFS_FS=y && FSCACHE=y)
+ depends on CACHEFILES_ONDEMAND && FSCACHE && \
+ (EROFS_FS=m && NETFS_SUPPORT || EROFS_FS=y && NETFS_SUPPORT=y)
default n
help
This permits EROFS to use fscache-backed data blobs with on-demand
Hi,
On 12/22/23 9:02 PM, David Howells wrote:
> This needs an additional change (see attached).
>
> diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
> index 1d318f85232d..1949763e66aa 100644
> --- a/fs/erofs/Kconfig
> +++ b/fs/erofs/Kconfig
> @@ -114,7 +114,8 @@ config EROFS_FS_ZIP_DEFLATE
>
> config EROFS_FS_ONDEMAND
> bool "EROFS fscache-based on-demand read support"
> - depends on CACHEFILES_ONDEMAND && (EROFS_FS=m && FSCACHE || EROFS_FS=y && FSCACHE=y)
> + depends on CACHEFILES_ONDEMAND && FSCACHE && \
> + (EROFS_FS=m && NETFS_SUPPORT || EROFS_FS=y && NETFS_SUPPORT=y)
> default n
> help
> This permits EROFS to use fscache-backed data blobs with on-demand
>
Thanks for the special reminder. I noticed that it has been included in
this commit[*] in the dev tree.
[*]
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit/?h=netfs-lib&id=7472173cc3baf4a0bd8c803e56c37efdb8388f1c
Besides I noticed an issue when trying to configure EROFS_FS_ONDEMAND.
The above kconfig indicates that EROFS_FS_ONDEMAND depends on
NETFS_SUPPORT, while NETFS_SUPPORT has no prompt in menuconfig and can
only be selected by, e.g. fs/ceph/Kconfig:
config CEPH_FS
select NETFS_SUPPORT
IOW EROFS_FS_ONDEMAND will not be prompted and has no way being
configured if NETFS_SUPPORT itself is not selected by any other filesystem.
I tried to fix this in following way:
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index 1949763e66aa..5b7b71e537f1 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -5,6 +5,7 @@ config EROFS_FS
depends on BLOCK
select FS_IOMAP
select LIBCRC32C
+ select NETFS_SUPPORT if EROFS_FS_ONDEMAND
help
EROFS (Enhanced Read-Only File System) is a lightweight read-only
file system with modern designs (e.g. no buffer heads, inline
@@ -114,8 +115,10 @@ config EROFS_FS_ZIP_DEFLATE
config EROFS_FS_ONDEMAND
bool "EROFS fscache-based on-demand read support"
- depends on CACHEFILES_ONDEMAND && FSCACHE && \
- (EROFS_FS=m && NETFS_SUPPORT || EROFS_FS=y &&
NETFS_SUPPORT=y)
+ depends on EROFS_FS
+ select FSCACHE
default n
help
This permits EROFS to use fscache-backed data blobs with on-demand
But still the dependency for CACHEFILES_ONDEMAND and CACHEFILES can not
be resolved. Though CACHEFILES is not a must during the linking stage
as EROFS only calls fscache APIs directly, CACHEFILES is indeed needed
to ensure that the EROFS on-demand functionality works at runtime.
If we let EROFS_FS_ONDEMAND select CACHEFILES_ONDEMAND, then only
CACHEFILES_ONDEMAND will be selected while CACHEFILES can be still N.
Maybe EROFS_FS_ONDEMAND needs to selct both CACHEFILES_ONDEMAND and
CACHEFILES?
Besides if we make EROFS_FS_ONDEMAND depends on CACHEFILES_ONDEMAND,
then there will be a recursive dependency loop, as
fs/netfs/Kconfig:3:error: recursive dependency detected!
fs/netfs/Kconfig:3: symbol NETFS_SUPPORT is selected by EROFS_FS_ONDEMAND
fs/erofs/Kconfig:116: symbol EROFS_FS_ONDEMAND depends on
CACHEFILES_ONDEMAND
fs/cachefiles/Kconfig:30: symbol CACHEFILES_ONDEMAND depends on CACHEFILES
fs/cachefiles/Kconfig:3: symbol CACHEFILES depends on NETFS_SUPPORT
Hi Xiang, any better idea?
--
Thanks,
Jingbo
Hi David and Jingbo,
On 2023/12/23 11:55, Jingbo Xu wrote:
> Hi,
>
> On 12/22/23 9:02 PM, David Howells wrote:
>> This needs an additional change (see attached).
>>
>> diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
>> index 1d318f85232d..1949763e66aa 100644
>> --- a/fs/erofs/Kconfig
>> +++ b/fs/erofs/Kconfig
>> @@ -114,7 +114,8 @@ config EROFS_FS_ZIP_DEFLATE
>>
>> config EROFS_FS_ONDEMAND
>> bool "EROFS fscache-based on-demand read support"
>> - depends on CACHEFILES_ONDEMAND && (EROFS_FS=m && FSCACHE || EROFS_FS=y && FSCACHE=y)
>> + depends on CACHEFILES_ONDEMAND && FSCACHE && \
>> + (EROFS_FS=m && NETFS_SUPPORT || EROFS_FS=y && NETFS_SUPPORT=y)
>> default n
>> help
>> This permits EROFS to use fscache-backed data blobs with on-demand
>>
>
> Thanks for the special reminder. I noticed that it has been included in
> this commit[*] in the dev tree.
>
> [*]
> https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit/?h=netfs-lib&id=7472173cc3baf4a0bd8c803e56c37efdb8388f1c
>
>
> Besides I noticed an issue when trying to configure EROFS_FS_ONDEMAND.
> The above kconfig indicates that EROFS_FS_ONDEMAND depends on
> NETFS_SUPPORT, while NETFS_SUPPORT has no prompt in menuconfig and can
> only be selected by, e.g. fs/ceph/Kconfig:
>
> config CEPH_FS
> select NETFS_SUPPORT
>
> IOW EROFS_FS_ONDEMAND will not be prompted and has no way being
> configured if NETFS_SUPPORT itself is not selected by any other filesystem.
>
>
> I tried to fix this in following way:
>
> diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
> index 1949763e66aa..5b7b71e537f1 100644
> --- a/fs/erofs/Kconfig
> +++ b/fs/erofs/Kconfig
> @@ -5,6 +5,7 @@ config EROFS_FS
> depends on BLOCK
> select FS_IOMAP
> select LIBCRC32C
> + select NETFS_SUPPORT if EROFS_FS_ONDEMAND
> help
> EROFS (Enhanced Read-Only File System) is a lightweight read-only
> file system with modern designs (e.g. no buffer heads, inline
> @@ -114,8 +115,10 @@ config EROFS_FS_ZIP_DEFLATE
>
> config EROFS_FS_ONDEMAND
> bool "EROFS fscache-based on-demand read support"
> - depends on CACHEFILES_ONDEMAND && FSCACHE && \
> - (EROFS_FS=m && NETFS_SUPPORT || EROFS_FS=y &&
> NETFS_SUPPORT=y)
> + depends on EROFS_FS
> + select FSCACHE
> default n
> help
> This permits EROFS to use fscache-backed data blobs with on-demand
>
>
> But still the dependency for CACHEFILES_ONDEMAND and CACHEFILES can not
> be resolved. Though CACHEFILES is not a must during the linking stage
> as EROFS only calls fscache APIs directly, CACHEFILES is indeed needed
> to ensure that the EROFS on-demand functionality works at runtime.
>
> If we let EROFS_FS_ONDEMAND select CACHEFILES_ONDEMAND, then only
> CACHEFILES_ONDEMAND will be selected while CACHEFILES can be still N.
> Maybe EROFS_FS_ONDEMAND needs to selct both CACHEFILES_ONDEMAND and
> CACHEFILES?
I think the main point here is that we don't have an explicit
menuconfig item for either netfs or fscache directly.
In principle, EROFS ondemand feature only needs fscache "volume
and cookie" management framework as well as cachefiles since
they're all needed to manage EROFS cached blobs, but I'm fine
if that needs NETFS_SUPPORT is also enabled.
If netfs doesn't have a plan for a new explicit menuconfig
item for users to use, I think we have to enable as below:
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index 1d318f85232d..fffd3919343e 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -114,8 +114,11 @@ config EROFS_FS_ZIP_DEFLATE
config EROFS_FS_ONDEMAND
bool "EROFS fscache-based on-demand read support"
- depends on CACHEFILES_ONDEMAND && (EROFS_FS=m && FSCACHE || EROFS_FS=y && FSCACHE=y)
- default n
+ depends on EROFS_FS
+ select NETFS_SUPPORT
+ select FSCACHE
+ select CACHEFILES
+ select CACHEFILES_ONDEMAND
help
This permits EROFS to use fscache-backed data blobs with on-demand
read support.
--
2.39.3
But cachefiles won't be complied as modules anymore. Does it
sounds good?
Thanks,
Gao Xiang
On Thu, Dec 21, 2023 at 01:23:10PM +0000, David Howells wrote:
> Add a bvec array pointer and an iterator to netfs_io_request for either
> holding a copy of a DIO iterator or a list of all the bits of buffer
> pointed to by a DIO iterator.
>
> There are two problems: Firstly, if an iovec-class iov_iter is passed to
> ->read_iter() or ->write_iter(), this cannot be passed directly to
> kernel_sendmsg() or kernel_recvmsg() as that may cause locking recursion if
> a fault is generated, so we need to keep track of the pages involved
> separately.
>
> Secondly, if the I/O is asynchronous, we must copy the iov_iter describing
> the buffer before returning to the caller as it may be immediately
> deallocated.
>
> Signed-off-by: David Howells <[email protected]>
> Reviewed-by: Jeff Layton <[email protected]>
> cc: [email protected]
> cc: [email protected]
> cc: [email protected]
> ---
> fs/netfs/objects.c | 10 ++++++++++
> include/linux/netfs.h | 4 ++++
> 2 files changed, 14 insertions(+)
>
> diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
> index 1bd20bdad983..4df5e5eeada6 100644
> --- a/fs/netfs/objects.c
> +++ b/fs/netfs/objects.c
> @@ -76,6 +76,7 @@ static void netfs_free_request(struct work_struct *work)
> {
> struct netfs_io_request *rreq =
> container_of(work, struct netfs_io_request, work);
> + unsigned int i;
>
> trace_netfs_rreq(rreq, netfs_rreq_trace_free);
> netfs_proc_del_rreq(rreq);
> @@ -84,6 +85,15 @@ static void netfs_free_request(struct work_struct *work)
> rreq->netfs_ops->free_request(rreq);
> if (rreq->cache_resources.ops)
> rreq->cache_resources.ops->end_operation(&rreq->cache_resources);
> + if (rreq->direct_bv) {
> + for (i = 0; i < rreq->direct_bv_count; i++) {
> + if (rreq->direct_bv[i].bv_page) {
> + if (rreq->direct_bv_unpin)
> + unpin_user_page(rreq->direct_bv[i].bv_page);
> + }
> + }
> + kvfree(rreq->direct_bv);
> + }
> kfree_rcu(rreq, rcu);
> netfs_stat_d(&netfs_n_rh_rreq);
> }
> diff --git a/include/linux/netfs.h b/include/linux/netfs.h
> index 3da962e977f5..bbb33ccbf719 100644
> --- a/include/linux/netfs.h
> +++ b/include/linux/netfs.h
> @@ -190,6 +190,9 @@ struct netfs_io_request {
> struct iov_iter iter; /* Unencrypted-side iterator */
> struct iov_iter io_iter; /* I/O (Encrypted-side) iterator */
> void *netfs_priv; /* Private data for the netfs */
> + struct bio_vec *direct_bv /* DIO buffer list (when handling iovec-iter) */
> + __counted_by(direct_bv_count);
This will break the build with versions of clang that have support for
counted_by (as it has been reverted in main but reapplication to main is
being actively worked on) because while annotating pointers with this
attribute is a goal of the counted_by attribute, it is not ready yet.
Please consider removing this and adding a TODO to annotate it when
support is available.
In file included from /builds/linux/fs/ceph/crypto.c:14:
In file included from /builds/linux/fs/ceph/super.h:20:
/builds/linux/include/linux/netfs.h:259:19: error: 'counted_by' only applies to C99 flexible array members
259 | struct bio_vec *direct_bv /* DIO buffer list (when handling iovec-iter) */
| ^~~~~~~~~
1 error generated.
Some additional context from another recent error like this:
https://lore.kernel.org/CAKwvOdkvGTGiWzqEFq=kzqvxSYP5vUj3g9Z-=MZSQROzzSa_dg@mail.gmail.com/
Cheers,
Nathan
> + unsigned int direct_bv_count; /* Number of elements in direct_bv[] */
> unsigned int debug_id;
> atomic_t nr_outstanding; /* Number of ops in progress */
> atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */
> @@ -197,6 +200,7 @@ struct netfs_io_request {
> size_t len; /* Length of the request */
> short error; /* 0 or error that occurred */
> enum netfs_io_origin origin; /* Origin of the request */
> + bool direct_bv_unpin; /* T if direct_bv[] must be unpinned */
> loff_t i_size; /* Size of the file */
> loff_t start; /* Start position */
> pgoff_t no_unlock_folio; /* Don't unlock this folio after read */
>
> This will break the build with versions of clang that have support for
> counted_by (as it has been reverted in main but reapplication to main is
> being actively worked on) because while annotating pointers with this
> attribute is a goal of the counted_by attribute, it is not ready yet.
> Please consider removing this and adding a TODO to annotate it when
> support is available.
It's really unpleasant that we keep getting new attributes that we
seemingly are encouraged to use and get sent patches for it. And then we
learn a little later that that stuff isn't ready yet. It's annoying. I
know it isn't your fault but it would be wise to be a little more
careful. IOW, unless both clang and gcc do support that thing
appropriately don't send patches to various subsystems for this.
In any case, this is now fixed. I pulled an updated version from David.
On Thu, Dec 28, 2023 at 11:47:45AM +0100, Christian Brauner wrote:
> > This will break the build with versions of clang that have support for
> > counted_by (as it has been reverted in main but reapplication to main is
> > being actively worked on) because while annotating pointers with this
> > attribute is a goal of the counted_by attribute, it is not ready yet.
> > Please consider removing this and adding a TODO to annotate it when
> > support is available.
>
> It's really unpleasant that we keep getting new attributes that we
> seemingly are encouraged to use and get sent patches for it. And then we
> learn a little later that that stuff isn't ready yet. It's annoying. I
I will assume the "get sent patches for it" is referring to the patches
that Kees has been sending out to add this attribute to flexible array
members. In his defense, that part of the attribute is very nearly ready
(it is only the pointer annotations that are not ready, as in not worked
on at all as far as I am aware). In fact, it was merged in clang's main
branch for some time and the only reason that it was backed out was
because adoption in the kernel had pointed out bugs in the original
implementation that were harder to fix than initially thought; in other
words, only because we started adding this attribute to the kernel were
we able to realize that the initial implementation in clang needed to be
improved, otherwise this feature may have shipped completely broken in
clang 18.1.0 because it had not been stress tested yet. Now we can get
it right.
However, I do not necessarily disagree that it is annoying for
maintainers who are not following this saga but are just receiving
patches to add these annotatations because adds additional things to
check for. Perhaps there should be some guidance added to the
__counted_by definition or Documentation around how it is expected to be
used so that there is clear advice for both developers and maintainers?
> know it isn't your fault but it would be wise to be a little more
> careful. IOW, unless both clang and gcc do support that thing
> appropriately don't send patches to various subsystems for this.
I will assume this was not necessarily directed at me because I have not
sent any patches for __counted_by.
> In any case, this is now fixed. I pulled an updated version from David.
Thanks a lot.
Cheers,
Nathan
On Fri, Dec 22, 2023 at 12:00:51PM +0000, David Howells wrote:
> David Howells <[email protected]> wrote:
>
> > A better way, though, is to move the call to nfs_netfs_inode_init()
> > and give it a flag to say whether or not we want the facility.
>
> Okay, I think I'll fold in the attached change.
This commit (100ccd18bb41 in linux-next 20240104) is bad for me. After
it, running xfstests gives me first a bunch of errors along these lines:
00004 depmod: ERROR: failed to load symbols from /lib/modules/6.7.0-rc7-00037-g100ccd18bb41/kernel/fs/gfs2/gfs2.ko: Exec format error
00004 depmod: ERROR: failed to load symbols from /lib/modules/6.7.0-rc7-00037-g100ccd18bb41/kernel/fs/zonefs/zonefs.ko: Exec format error
00004 depmod: ERROR: failed to load symbols from /lib/modules/6.7.0-rc7-00037-g100ccd18bb41/kernel/security/keys/encrypted-keys/encrypted-keys.ko: Exec format error
and then later:
00016 generic/001 run fstests generic/001 at 2024-01-05 04:50:46
00017 [not run] this test requires a valid $TEST_DEV
00017 generic/002 run fstests generic/002 at 2024-01-05 04:50:46
00017 [not run] this test requires a valid $TEST_DEV
00017 generic/003 run fstests generic/003 at 2024-01-05 04:50:47
00018 [not run] this test requires a valid $SCRATCH_DEV
...
so I think that's page cache corruption of some kind.
Do you have CONFIG_NFS_FSCACHE set? Are you using a cache?
David
On Fri, Jan 05, 2024 at 10:12:55AM +0000, David Howells wrote:
> Matthew Wilcox <[email protected]> wrote:
>
> > This commit (100ccd18bb41 in linux-next 20240104) is bad for me. After
> > it, running xfstests gives me first a bunch of errors along these lines:
> >
> > 00004 depmod: ERROR: failed to load symbols from /lib/modules/6.7.0-rc7-00037-g100ccd18bb41/kernel/fs/gfs2/gfs2.ko: Exec format error
> > 00004 depmod: ERROR: failed to load symbols from /lib/modules/6.7.0-rc7-00037-g100ccd18bb41/kernel/fs/zonefs/zonefs.ko: Exec format error
> > 00004 depmod: ERROR: failed to load symbols from /lib/modules/6.7.0-rc7-00037-g100ccd18bb41/kernel/security/keys/encrypted-keys/encrypted-keys.ko: Exec format error
> >
> > and then later:
> >
> > 00016 generic/001 run fstests generic/001 at 2024-01-05 04:50:46
> > 00017 [not run] this test requires a valid $TEST_DEV
> > 00017 generic/002 run fstests generic/002 at 2024-01-05 04:50:46
> > 00017 [not run] this test requires a valid $TEST_DEV
> > 00017 generic/003 run fstests generic/003 at 2024-01-05 04:50:47
> > 00018 [not run] this test requires a valid $SCRATCH_DEV
> > ...
> >
> > so I think that's page cache corruption of some kind.
>
> Is that being run on NFS? Is /lib on NFS?
No NFS involvement; this is supposed to be an XFS test ...
/dev/sda on / type ext4 (rw,relatime)
host on /host type 9p (rw,relatime,access=client,trans=virtio)
/dev/sdb on /mnt/test type xfs (rw,relatime,attr2,inode64,logbufs=8,logbsize=32k,noquota)
CONFIG_NETFS_SUPPORT=y
# CONFIG_NETFS_STATS is not set
# CONFIG_FSCACHE is not set
CONFIG_NETWORK_FILESYSTEMS=y
# CONFIG_NFS_FS is not set
# CONFIG_NFSD is not set
# CONFIG_CEPH_FS is not set
# CONFIG_CIFS is not set
# CONFIG_SMB_SERVER is not set
# CONFIG_CODA_FS is not set
# CONFIG_AFS_FS is not set
CONFIG_9P_FS=y
# CONFIG_9P_FS_POSIX_ACL is not set
# CONFIG_9P_FS_SECURITY is not set
CONFIG_NLS=y
Matthew Wilcox <[email protected]> wrote:
> This commit (100ccd18bb41 in linux-next 20240104) is bad for me. After
> it, running xfstests gives me first a bunch of errors along these lines:
This may be related to a patch that is in linux-next 20240105, but not
20240104 ("9p: Fix initialisation of netfs_inode for 9p").
David
Matthew Wilcox wrote on Fri, Jan 05, 2024 at 01:17:36PM +0000:
> host on /host type 9p (rw,relatime,access=client,trans=virtio)
David Howells wrote on Fri, Jan 05, 2024 at 02:33:32PM +0000:
> > This commit (100ccd18bb41 in linux-next 20240104) is bad for me. After
> > it, running xfstests gives me first a bunch of errors along these lines:
>
> This may be related to a patch that is in linux-next 20240105, but not
> 20240104 ("9p: Fix initialisation of netfs_inode for 9p").
Yes, you'd be reading zeroes without that patch because the netfs code
thinks the file has 0 size and doesn't bother reading, that'd explain
the exec format error loading other modules...
One thing that surprised me is that this also affects cache=none, I
thought we had different file ops going straight to p9_client_read in
this case?
But turning my brain on this would be the read-only mmap case that we
need to support for execs, which module loading also uses, so this came
biting there alright.
--
Dominique Martinet | Asmadeus