This patchset converts NFS with fscache non-direct READ IO paths to
use the netfs API with a non-invasive approach. The existing NFS pgio
layer does not need extensive changes, and is the best way so far I've
found to address Trond's concerns about modifying the IO path [1] as
well as only enabling netfs when fscache is configured and enabled [2].
I have not attempted performance comparisions to address Chuck
Lever's concern [3] because we are not converting the non-fscache
enabled NFS IO paths to netfs.
The main patch to be reviewed is patch #3 which converts nfs_read_folio
and nfs_readahead.
The patchset is based on 6.0-rc5 and has been pushed to github at:
https://github.com/DaveWysochanskiRH/kernel/commits/nfs-fscache-netfs
https://github.com/DaveWysochanskiRH/kernel/commit/7d57f6484951800de518f555a04a3a4dc4a1327c
Changes since v6
================
PATCH3: Fix generic/127 "Subreq overread" by calling netfs_subreq_terminated()
with a length capped by sreq->len. This is related to the following patch which
may cause us to read a full page even if the i_size does not extend to the end of
the page:
8cfb9015280d NFS: Always provide aligned buffers to the RPC read layers
Testing
=======
The patches are fairly stable as evidenced with xfstests generic with
various servers, both with and without fscache enabled, with no hangs
or crashes seen:
hammerspace(pNFS flexfiles): NFS4.1, NFS4.2
NetApp(pNFS filelayout): NFS3, NFS4.0, NFS4.1
RHEL8: NFS3,NFS4.1,NFS4.2
The known issues are as follows:
1. Unit test setting rsize < readahead does not properly read from
fscache but re-reads data from the NFS server
* This will be fixed with another linux-cachefs [4] patch to resolve
"Stop read optimisation when folio removed from pagecache"
* Daire Byrne also verified the patch fixes his issue as well
2. "Cache volume key already in use" after xfstest runs
* xfstests (hammerspace with vers=4.2,fsc) shows the following on the
console after some tests:
"NFS: Cache volume key already in use (nfs,4.1,2,c50,cfe0100a,3,,,8000,100000,100000,bb8,ea60,7530,ea60,1)"
* This may be fixed with another patch [5] that is in progress
3. Daire Byrne reported a NULL pointer oops at cachefiles_prepare_write+0x28/0x90
* may be a bug in netfs or cachefiles exposed by NFS patches
* under investigation
[58710.346376] BUG: kernel NULL pointer dereference, address: 0000000000000008
[58710.371212] CPU: 12 PID: 9134 Comm: kworker/u129:0 Tainted: G E 6.0.0-2.dneg.x86_64 #1
...
[58710.389995] Workqueue: events_unbound netfs_rreq_write_to_cache_work [netfs]
[58710.397188] RIP: 0010:cachefiles_prepare_write+0x28/0x90 [cachefiles]
...
[58710.500316] Call Trace:
[58710.502894] <TASK>
[58710.505126] netfs_rreq_write_to_cache_work+0x11c/0x320 [netfs]
[58710.511201] process_one_work+0x217/0x3e0
[58710.515358] worker_thread+0x4a/0x3b0
[58710.519152] ? process_one_work+0x3e0/0x3e0
[58710.523467] kthread+0xd6/0x100
[58710.526740] ? kthread_complete_and_exit+0x20/0x20
[58710.531659] ret_from_fork+0x1f/0x30
Outstanding
===========
Note that the existing NFS fscache stats ("fsc:" line in /proc/self/mountstats)
as well as trace events still need removed. I've left these out of
this patchset for now as removing them are benign and can come later
(the stats will all be 0, and trace events are no longer used).
The existing NFS fscache stat counts no longer apply since the new
API is not page based - they are not meaningful or possible to obtain,
and there are new fscache stats in /proc/fs/fscache/stats. A similar
situation exists with the NFS trace events - netfs and fscache have
plenty of trace events so the NFS specific ones probably are not needed.
References
==========
[1] https://lore.kernel.org/linux-nfs/[email protected]/
[2] https://lore.kernel.org/linux-nfs/[email protected]/
[3] https://marc.info/?l=linux-nfs&m=160597917525083&w=4
[4] https://www.mail-archive.com/[email protected]/msg03043.html
[5] https://marc.info/?l=linux-nfs&m=165962662200679&w=4
Dave Wysochanski (3):
NFS: Rename readpage_async_filler to nfs_pageio_add_page
NFS: Configure support for netfs when NFS fscache is configured
NFS: Convert buffered read paths to use netfs when fscache is enabled
fs/nfs/Kconfig | 1 +
fs/nfs/delegation.c | 2 +-
fs/nfs/dir.c | 2 +-
fs/nfs/fscache.c | 251 +++++++++++++++++++++++----------------
fs/nfs/fscache.h | 113 ++++++++++++------
fs/nfs/inode.c | 8 +-
fs/nfs/internal.h | 11 +-
fs/nfs/pagelist.c | 12 ++
fs/nfs/pnfs.c | 12 +-
fs/nfs/read.c | 111 +++++++++--------
fs/nfs/write.c | 2 +-
include/linux/nfs_fs.h | 34 ++++--
include/linux/nfs_page.h | 3 +
include/linux/nfs_xdr.h | 3 +
14 files changed, 347 insertions(+), 218 deletions(-)
--
2.31.1
As first steps for support of the netfs library when NFS_FSCACHE is
configured, add NETFS_SUPPORT to Kconfig and add the required netfs_inode
into struct nfs_inode.
Using netfs requires we move the VFS inode structure to be stored
inside struct netfs_inode, along with the fscache_cookie.
Thus, create a new helper, VFS_I(), which is defined
differently depending on whether NFS_FSCACHE is configured.
In addition, use the netfs_inode() and netfs_i_cookie() helpers,
and remove our own helper, nfs_i_fscache().
Later patches will convert NFS fscache to fully use netfs.
Signed-off-by: Dave Wysochanski <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
---
fs/nfs/Kconfig | 1 +
fs/nfs/delegation.c | 2 +-
fs/nfs/dir.c | 2 +-
fs/nfs/fscache.c | 20 +++++++++-----------
fs/nfs/fscache.h | 15 ++++++---------
fs/nfs/inode.c | 6 +++---
fs/nfs/internal.h | 2 +-
fs/nfs/pnfs.c | 12 ++++++------
fs/nfs/write.c | 2 +-
include/linux/nfs_fs.h | 34 +++++++++++++++++++++++-----------
10 files changed, 52 insertions(+), 44 deletions(-)
diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index 14a72224b657..8fbb6caf3481 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -171,6 +171,7 @@ 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
help
Say Y here if you want NFS data to be cached locally on disc through
the general filesystem cache manager
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 5c97cad741a7..b5c492d40367 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -306,7 +306,7 @@ nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
}
spin_unlock(&delegation->lock);
if (ret)
- nfs_clear_verifier_delegated(&nfsi->vfs_inode);
+ nfs_clear_verifier_delegated(VFS_I(nfsi));
out:
return ret;
}
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 5d6c2ddc7ea6..b63c624cea6d 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2799,7 +2799,7 @@ nfs_do_access_cache_scan(unsigned int nr_to_scan)
if (nr_to_scan-- == 0)
break;
- inode = &nfsi->vfs_inode;
+ inode = VFS_I(nfsi);
spin_lock(&inode->i_lock);
if (list_empty(&nfsi->access_cache_entry_lru))
goto remove_lru_entry;
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
index e861d7bae305..a6fc1c8b6644 100644
--- a/fs/nfs/fscache.c
+++ b/fs/nfs/fscache.c
@@ -163,13 +163,14 @@ void nfs_fscache_init_inode(struct inode *inode)
struct nfs_server *nfss = NFS_SERVER(inode);
struct nfs_inode *nfsi = NFS_I(inode);
- nfsi->fscache = NULL;
+ netfs_inode(inode)->cache = NULL;
if (!(nfss->fscache && S_ISREG(inode->i_mode)))
return;
nfs_fscache_update_auxdata(&auxdata, inode);
- nfsi->fscache = fscache_acquire_cookie(NFS_SB(inode->i_sb)->fscache,
+ netfs_inode(inode)->cache = fscache_acquire_cookie(
+ nfss->fscache,
0,
nfsi->fh.data, /* index_key */
nfsi->fh.size,
@@ -183,11 +184,8 @@ void nfs_fscache_init_inode(struct inode *inode)
*/
void nfs_fscache_clear_inode(struct inode *inode)
{
- struct nfs_inode *nfsi = NFS_I(inode);
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
-
- fscache_relinquish_cookie(cookie, false);
- nfsi->fscache = NULL;
+ fscache_relinquish_cookie(netfs_i_cookie(&NFS_I(inode)->netfs), false);
+ netfs_inode(inode)->cache = NULL;
}
/*
@@ -212,7 +210,7 @@ void nfs_fscache_clear_inode(struct inode *inode)
void nfs_fscache_open_file(struct inode *inode, struct file *filp)
{
struct nfs_fscache_inode_auxdata auxdata;
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
bool open_for_write = inode_is_open_for_write(inode);
if (!fscache_cookie_valid(cookie))
@@ -230,7 +228,7 @@ EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
void nfs_fscache_release_file(struct inode *inode, struct file *filp)
{
struct nfs_fscache_inode_auxdata auxdata;
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
loff_t i_size = i_size_read(inode);
nfs_fscache_update_auxdata(&auxdata, inode);
@@ -243,7 +241,7 @@ void nfs_fscache_release_file(struct inode *inode, struct file *filp)
static int fscache_fallback_read_page(struct inode *inode, struct page *page)
{
struct netfs_cache_resources cres;
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
struct iov_iter iter;
struct bio_vec bvec[1];
int ret;
@@ -271,7 +269,7 @@ static int fscache_fallback_write_page(struct inode *inode, struct page *page,
bool no_space_allocated_yet)
{
struct netfs_cache_resources cres;
- struct fscache_cookie *cookie = nfs_i_fscache(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
struct iov_iter iter;
struct bio_vec bvec[1];
loff_t start = page_offset(page);
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
index 2a37af880978..38614ed8f951 100644
--- a/fs/nfs/fscache.h
+++ b/fs/nfs/fscache.h
@@ -54,7 +54,7 @@ static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
if (current_is_kswapd() || !(gfp & __GFP_FS))
return false;
folio_wait_fscache(folio);
- fscache_note_page_release(nfs_i_fscache(folio->mapping->host));
+ fscache_note_page_release(netfs_i_cookie(&NFS_I(folio->mapping->host)->netfs));
nfs_inc_fscache_stats(folio->mapping->host,
NFSIOS_FSCACHE_PAGES_UNCACHED);
}
@@ -66,7 +66,7 @@ static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
*/
static inline int nfs_fscache_read_page(struct inode *inode, struct page *page)
{
- if (nfs_i_fscache(inode))
+ if (netfs_inode(inode)->cache)
return __nfs_fscache_read_page(inode, page);
return -ENOBUFS;
}
@@ -78,7 +78,7 @@ static inline int nfs_fscache_read_page(struct inode *inode, struct page *page)
static inline void nfs_fscache_write_page(struct inode *inode,
struct page *page)
{
- if (nfs_i_fscache(inode))
+ if (netfs_inode(inode)->cache)
__nfs_fscache_write_page(inode, page);
}
@@ -101,13 +101,10 @@ static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *
static inline void nfs_fscache_invalidate(struct inode *inode, int flags)
{
struct nfs_fscache_inode_auxdata auxdata;
- struct nfs_inode *nfsi = NFS_I(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
- if (nfsi->fscache) {
- nfs_fscache_update_auxdata(&auxdata, inode);
- fscache_invalidate(nfsi->fscache, &auxdata,
- i_size_read(inode), flags);
- }
+ nfs_fscache_update_auxdata(&auxdata, inode);
+ fscache_invalidate(cookie, &auxdata, i_size_read(inode), flags);
}
/*
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index bea7c005119c..aa2aec785ab5 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1411,7 +1411,7 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
static bool nfs_file_has_writers(struct nfs_inode *nfsi)
{
- struct inode *inode = &nfsi->vfs_inode;
+ struct inode *inode = VFS_I(nfsi);
if (!S_ISREG(inode->i_mode))
return false;
@@ -2249,7 +2249,7 @@ struct inode *nfs_alloc_inode(struct super_block *sb)
#ifdef CONFIG_NFS_V4_2
nfsi->xattr_cache = NULL;
#endif
- return &nfsi->vfs_inode;
+ return VFS_I(nfsi);
}
EXPORT_SYMBOL_GPL(nfs_alloc_inode);
@@ -2273,7 +2273,7 @@ static void init_once(void *foo)
{
struct nfs_inode *nfsi = (struct nfs_inode *) foo;
- inode_init_once(&nfsi->vfs_inode);
+ inode_init_once(VFS_I(nfsi));
INIT_LIST_HEAD(&nfsi->open_files);
INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 27c720d71b4e..273687082992 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -355,7 +355,7 @@ nfs4_label_copy(struct nfs4_label *dst, struct nfs4_label *src)
static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
{
- if (nfs_server_capable(&nfsi->vfs_inode, NFS_CAP_SECURITY_LABEL))
+ if (nfs_server_capable(VFS_I(nfsi), NFS_CAP_SECURITY_LABEL))
nfsi->cache_validity |= NFS_INO_INVALID_LABEL;
}
#else
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 2613b7e36eb9..035bf2eac2cf 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -763,19 +763,19 @@ static struct pnfs_layout_hdr *__pnfs_destroy_layout(struct nfs_inode *nfsi)
struct pnfs_layout_hdr *lo;
LIST_HEAD(tmp_list);
- spin_lock(&nfsi->vfs_inode.i_lock);
+ spin_lock(&VFS_I(nfsi)->i_lock);
lo = nfsi->layout;
if (lo) {
pnfs_get_layout_hdr(lo);
pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
- spin_unlock(&nfsi->vfs_inode.i_lock);
+ spin_unlock(&VFS_I(nfsi)->i_lock);
pnfs_free_lseg_list(&tmp_list);
- nfs_commit_inode(&nfsi->vfs_inode, 0);
+ nfs_commit_inode(VFS_I(nfsi), 0);
pnfs_put_layout_hdr(lo);
} else
- spin_unlock(&nfsi->vfs_inode.i_lock);
+ spin_unlock(&VFS_I(nfsi)->i_lock);
return lo;
}
@@ -790,9 +790,9 @@ static bool pnfs_layout_removed(struct nfs_inode *nfsi,
{
bool ret;
- spin_lock(&nfsi->vfs_inode.i_lock);
+ spin_lock(&VFS_I(nfsi)->i_lock);
ret = nfsi->layout != lo;
- spin_unlock(&nfsi->vfs_inode.i_lock);
+ spin_unlock(&VFS_I(nfsi)->i_lock);
return ret;
}
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 1843fa235d9b..d84121799a7a 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -828,7 +828,7 @@ nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
{
struct nfs_page *freq, *t;
struct nfs_commit_info cinfo;
- struct inode *inode = &nfsi->vfs_inode;
+ struct inode *inode = VFS_I(nfsi);
nfs_init_cinfo_from_inode(&cinfo, inode);
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 7931fa472561..a1c402e26abf 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -31,6 +31,10 @@
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/clnt.h>
+#ifdef CONFIG_NFS_FSCACHE
+#include <linux/netfs.h>
+#endif
+
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs3.h>
@@ -204,9 +208,11 @@ struct nfs_inode {
__u64 write_io;
__u64 read_io;
#ifdef CONFIG_NFS_FSCACHE
- struct fscache_cookie *fscache;
-#endif
+ struct netfs_inode netfs; /* netfs context and VFS inode */
+#else
struct inode vfs_inode;
+#endif
+
#ifdef CONFIG_NFS_V4_2
struct nfs4_xattr_cache *xattr_cache;
@@ -281,10 +287,25 @@ struct nfs4_copy_state {
#define NFS_INO_LAYOUTSTATS (11) /* layoutstats inflight */
#define NFS_INO_ODIRECT (12) /* I/O setting is O_DIRECT */
+#ifdef CONFIG_NFS_FSCACHE
+static inline struct inode *VFS_I(struct nfs_inode *nfsi)
+{
+ return &nfsi->netfs.inode;
+}
+static inline struct nfs_inode *NFS_I(const struct inode *inode)
+{
+ return container_of(inode, struct nfs_inode, netfs.inode);
+}
+#else
+static inline struct inode *VFS_I(struct nfs_inode *nfsi)
+{
+ return &nfsi->vfs_inode;
+}
static inline struct nfs_inode *NFS_I(const struct inode *inode)
{
return container_of(inode, struct nfs_inode, vfs_inode);
}
+#endif
static inline struct nfs_server *NFS_SB(const struct super_block *s)
{
@@ -328,15 +349,6 @@ static inline int NFS_STALE(const struct inode *inode)
return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
}
-static inline struct fscache_cookie *nfs_i_fscache(struct inode *inode)
-{
-#ifdef CONFIG_NFS_FSCACHE
- return NFS_I(inode)->fscache;
-#else
- return NULL;
-#endif
-}
-
static inline __u64 NFS_FILEID(const struct inode *inode)
{
return NFS_I(inode)->fileid;
--
2.31.1