Please find the series which rewrites ext2 direct-io path to use modern
iomap interface.
RFCv3 -> RFCV4:
===============
1. Renamed __generic_file_fsync_nolock() from libfs to generic_buffer_fsync() in
fs/buffer.c
(Review comment from Christoph)
2. Fixed s/EVENTD/EVENTFD/ in TRACE_IOCB_STRINGS
3. Fixed few data types for parameters in ext2 trace patch (size_t && ssize_t)
4. Killed this patch "Minor refactor of iomap_dio_rw"
5. Changed iomap tracepoint patch and fixed the data types (size_t && ssize_t)
(addressed review comments from Christoph)
RFCv2 -> RFCv3:
===============
1. Addressed minor review comments related to extern, parameter naming in
function declaration, removing not required braces and shorting overly long
lines.
2. Added Reviewed-by from various reviewers.
3. Fixed a warning & couple of compilation errors in Patch-7 (ext2 trace points)
related to CFLAGS_trace & second related to unable to find function
definition for iov_iter_count(). (requires uio.h file)
CFLAGS_trace is required in Makefile so that it can find trace.h file from
tracepoint infrastructure.
4. Changed naming of IOCB_STRINGS TO TRACE_IOCB_STRINGS.
5. Shortened naming of tracepoint events for ext2 dio.
6. Added iomap DIO tracepoint events.
7. Disha tested this series internally against Power with "auto" group for 4k
and 64k blocksize configuration. Added her "Tested-by" tag in all DIO
related patches. No new failures were reported.
Thanks everyone for the review and test. The series is looking good to me now.
It has now been tested on x86 and Power with different configurations.
Please let me know if anything else is required on this.
v2: https://lore.kernel.org/all/[email protected]/
Ritesh Harjani (IBM) (9):
ext2/dax: Fix ext2_setsize when len is page aligned
fs/buffer.c: Add generic_buffer_fsync implementation
ext4: Use generic_buffer_fsync() implementation
ext2: Use generic_buffer_fsync() implementation
ext2: Move direct-io to use iomap
fs.h: Add TRACE_IOCB_STRINGS for use in trace points
ext2: Add direct-io trace points
iomap: Remove IOMAP_DIO_NOSYNC unused dio flag
iomap: Add couple of DIO tracepoints
fs/buffer.c | 43 ++++++++++++
fs/ext2/Makefile | 5 +-
fs/ext2/ext2.h | 1 +
fs/ext2/file.c | 128 +++++++++++++++++++++++++++++++++++-
fs/ext2/inode.c | 58 +++++++++-------
fs/ext2/trace.c | 6 ++
fs/ext2/trace.h | 94 ++++++++++++++++++++++++++
fs/ext4/fsync.c | 32 ++++-----
fs/iomap/direct-io.c | 7 +-
fs/iomap/trace.c | 1 +
fs/iomap/trace.h | 35 ++++++++++
include/linux/buffer_head.h | 2 +
include/linux/fs.h | 14 ++++
include/linux/iomap.h | 6 --
14 files changed, 384 insertions(+), 48 deletions(-)
create mode 100644 fs/ext2/trace.c
create mode 100644 fs/ext2/trace.h
--
2.39.2
ext4 when got converted to iomap for dio, it copied __generic_file_fsync
implementation to avoid taking inode_lock in order to avoid any deadlock
(since iomap takes an inode_lock while calling generic_write_sync()).
The previous patch already added generic_buffer_fsync() which does not
take any inode_lock(). Hence kill the redundant code and use
generic_buffer_fsync() function instead.
Tested-by: Disha Goel <[email protected]>
Signed-off-by: Ritesh Harjani (IBM) <[email protected]>
---
fs/ext4/fsync.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 027a7d7037a0..4f2af43f8b0f 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -28,6 +28,7 @@
#include <linux/sched.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
+#include <linux/buffer_head.h>
#include "ext4.h"
#include "ext4_jbd2.h"
@@ -78,21 +79,13 @@ static int ext4_sync_parent(struct inode *inode)
return ret;
}
-static int ext4_fsync_nojournal(struct inode *inode, bool datasync,
- bool *needs_barrier)
+static int ext4_fsync_nojournal(struct file *file, loff_t start, loff_t end,
+ int datasync, bool *needs_barrier)
{
- int ret, err;
-
- ret = sync_mapping_buffers(inode->i_mapping);
- if (!(inode->i_state & I_DIRTY_ALL))
- return ret;
- if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
- return ret;
-
- err = sync_inode_metadata(inode, 1);
- if (!ret)
- ret = err;
+ struct inode *inode = file->f_inode;
+ int ret;
+ ret = generic_buffer_fsync(file, start, end, datasync);
if (!ret)
ret = ext4_sync_parent(inode);
if (test_opt(inode->i_sb, BARRIER))
@@ -148,6 +141,14 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
goto out;
}
+ if (!sbi->s_journal) {
+ ret = ext4_fsync_nojournal(file, start, end, datasync,
+ &needs_barrier);
+ if (needs_barrier)
+ goto issue_flush;
+ goto out;
+ }
+
ret = file_write_and_wait_range(file, start, end);
if (ret)
goto out;
@@ -166,13 +167,12 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
* (they were dirtied by commit). But that's OK - the blocks are
* safe in-journal, which is all fsync() needs to ensure.
*/
- if (!sbi->s_journal)
- ret = ext4_fsync_nojournal(inode, datasync, &needs_barrier);
- else if (ext4_should_journal_data(inode))
+ if (ext4_should_journal_data(inode))
ret = ext4_force_commit(inode->i_sb);
else
ret = ext4_fsync_journal(inode, datasync, &needs_barrier);
+issue_flush:
if (needs_barrier) {
err = blkdev_issue_flush(inode->i_sb->s_bdev);
if (!ret)
--
2.39.2
This patch converts ext2 direct-io path to iomap interface.
- This also takes care of DIO_SKIP_HOLES part in which we return -ENOTBLK
from ext2_iomap_begin(), in case if the write is done on a hole.
- This fallbacks to buffered-io in case of DIO_SKIP_HOLES or in case of
a partial write or if any error is detected in ext2_iomap_end().
We try to return -ENOTBLK in such cases.
- For any unaligned or extending DIO writes, we pass
IOMAP_DIO_FORCE_WAIT flag to ensure synchronous writes.
- For extending writes we set IOMAP_F_DIRTY in ext2_iomap_begin because
otherwise with dsync writes on devices that support FUA, generic_write_sync
won't be called and we might miss inode metadata updates.
- Since ext2 already now uses _nolock vartiant of sync write. Hence
there is no inode lock problem with iomap in this patch.
- ext2_iomap_ops are now being shared by DIO, DAX & fiemap path
Tested-by: Disha Goel <[email protected]>
Signed-off-by: Ritesh Harjani (IBM) <[email protected]>
---
fs/ext2/ext2.h | 1 +
fs/ext2/file.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/ext2/inode.c | 53 ++++++++++++++--------
3 files changed, 150 insertions(+), 19 deletions(-)
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index cb78d7dcfb95..00168447d48c 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -753,6 +753,7 @@ extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
extern struct inode *ext2_iget (struct super_block *, unsigned long);
extern int ext2_write_inode (struct inode *, struct writeback_control *);
extern void ext2_evict_inode(struct inode *);
+void ext2_write_failed(struct address_space *mapping, loff_t to);
extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
extern int ext2_setattr (struct mnt_idmap *, struct dentry *, struct iattr *);
extern int ext2_getattr (struct mnt_idmap *, const struct path *,
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index 7603427fb38f..704abe0a79cb 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -164,12 +164,124 @@ int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
return ret;
}
+static ssize_t ext2_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ ssize_t ret;
+
+ inode_lock_shared(inode);
+ ret = iomap_dio_rw(iocb, to, &ext2_iomap_ops, NULL, 0, NULL, 0);
+ inode_unlock_shared(inode);
+
+ return ret;
+}
+
+static int ext2_dio_write_end_io(struct kiocb *iocb, ssize_t size,
+ int error, unsigned int flags)
+{
+ loff_t pos = iocb->ki_pos;
+ struct inode *inode = file_inode(iocb->ki_filp);
+
+ if (error)
+ goto out;
+
+ /*
+ * If we are extending the file, we have to update i_size here before
+ * page cache gets invalidated in iomap_dio_rw(). This prevents racing
+ * buffered reads from zeroing out too much from page cache pages.
+ * Note that all extending writes always happens synchronously with
+ * inode lock held by ext2_dio_write_iter(). So it is safe to update
+ * inode size here for extending file writes.
+ */
+ pos += size;
+ if (pos > i_size_read(inode)) {
+ i_size_write(inode, pos);
+ mark_inode_dirty(inode);
+ }
+out:
+ return error;
+}
+
+static const struct iomap_dio_ops ext2_dio_write_ops = {
+ .end_io = ext2_dio_write_end_io,
+};
+
+static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ ssize_t ret;
+ unsigned int flags = 0;
+ unsigned long blocksize = inode->i_sb->s_blocksize;
+ loff_t offset = iocb->ki_pos;
+ loff_t count = iov_iter_count(from);
+
+ inode_lock(inode);
+ ret = generic_write_checks(iocb, from);
+ if (ret <= 0)
+ goto out_unlock;
+
+ ret = kiocb_modified(iocb);
+ if (ret)
+ goto out_unlock;
+
+ /* use IOMAP_DIO_FORCE_WAIT for unaligned or extending writes */
+ if (iocb->ki_pos + iov_iter_count(from) > i_size_read(inode) ||
+ (!IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(from), blocksize)))
+ flags |= IOMAP_DIO_FORCE_WAIT;
+
+ ret = iomap_dio_rw(iocb, from, &ext2_iomap_ops, &ext2_dio_write_ops,
+ flags, NULL, 0);
+
+ /* ENOTBLK is magic return value for fallback to buffered-io */
+ if (ret == -ENOTBLK)
+ ret = 0;
+
+ if (ret < 0 && ret != -EIOCBQUEUED)
+ ext2_write_failed(inode->i_mapping, offset + count);
+
+ /* handle case for partial write and for fallback to buffered write */
+ if (ret >= 0 && iov_iter_count(from)) {
+ loff_t pos, endbyte;
+ ssize_t status;
+ int ret2;
+
+ iocb->ki_flags &= ~IOCB_DIRECT;
+ pos = iocb->ki_pos;
+ status = generic_perform_write(iocb, from);
+ if (unlikely(status < 0)) {
+ ret = status;
+ goto out_unlock;
+ }
+
+ iocb->ki_pos += status;
+ ret += status;
+ endbyte = pos + status - 1;
+ ret2 = filemap_write_and_wait_range(inode->i_mapping, pos,
+ endbyte);
+ if (!ret2)
+ invalidate_mapping_pages(inode->i_mapping,
+ pos >> PAGE_SHIFT,
+ endbyte >> PAGE_SHIFT);
+ if (ret > 0)
+ generic_write_sync(iocb, ret);
+ }
+
+out_unlock:
+ inode_unlock(inode);
+ return ret;
+}
+
static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
#ifdef CONFIG_FS_DAX
if (IS_DAX(iocb->ki_filp->f_mapping->host))
return ext2_dax_read_iter(iocb, to);
#endif
+ if (iocb->ki_flags & IOCB_DIRECT)
+ return ext2_dio_read_iter(iocb, to);
+
return generic_file_read_iter(iocb, to);
}
@@ -179,6 +291,9 @@ static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
if (IS_DAX(iocb->ki_filp->f_mapping->host))
return ext2_dax_write_iter(iocb, from);
#endif
+ if (iocb->ki_flags & IOCB_DIRECT)
+ return ext2_dio_write_iter(iocb, from);
+
return generic_file_write_iter(iocb, from);
}
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index dc76147e7b07..75983215c7a1 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -56,7 +56,7 @@ static inline int ext2_inode_is_fast_symlink(struct inode *inode)
static void ext2_truncate_blocks(struct inode *inode, loff_t offset);
-static void ext2_write_failed(struct address_space *mapping, loff_t to)
+void ext2_write_failed(struct address_space *mapping, loff_t to)
{
struct inode *inode = mapping->host;
@@ -809,9 +809,27 @@ static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
bool new = false, boundary = false;
u32 bno;
int ret;
+ bool create = flags & IOMAP_WRITE;
+
+ /*
+ * For writes that could fill holes inside i_size on a
+ * DIO_SKIP_HOLES filesystem we forbid block creations: only
+ * overwrites are permitted.
+ */
+ if ((flags & IOMAP_DIRECT) &&
+ (first_block << blkbits) < i_size_read(inode))
+ create = 0;
+
+ /*
+ * Writes that span EOF might trigger an IO size update on completion,
+ * so consider them to be dirty for the purposes of O_DSYNC even if
+ * there is no other metadata changes pending or have been made here.
+ */
+ if ((flags & IOMAP_WRITE) && offset + length > i_size_read(inode))
+ iomap->flags |= IOMAP_F_DIRTY;
ret = ext2_get_blocks(inode, first_block, max_blocks,
- &bno, &new, &boundary, flags & IOMAP_WRITE);
+ &bno, &new, &boundary, create);
if (ret < 0)
return ret;
@@ -823,6 +841,12 @@ static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
iomap->bdev = inode->i_sb->s_bdev;
if (ret == 0) {
+ /*
+ * Switch to buffered-io for writing to holes in a non-extent
+ * based filesystem to avoid stale data exposure problem.
+ */
+ if (!create && (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT))
+ return -ENOTBLK;
iomap->type = IOMAP_HOLE;
iomap->addr = IOMAP_NULL_ADDR;
iomap->length = 1 << blkbits;
@@ -844,6 +868,13 @@ static int
ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length,
ssize_t written, unsigned flags, struct iomap *iomap)
{
+ /*
+ * Switch to buffered-io in case of any error.
+ * Blocks allocated can be used by the buffered-io path.
+ */
+ if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE) && written == 0)
+ return -ENOTBLK;
+
if (iomap->type == IOMAP_MAPPED &&
written < length &&
(flags & IOMAP_WRITE))
@@ -908,22 +939,6 @@ static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
return generic_block_bmap(mapping,block,ext2_get_block);
}
-static ssize_t
-ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
-{
- struct file *file = iocb->ki_filp;
- struct address_space *mapping = file->f_mapping;
- struct inode *inode = mapping->host;
- size_t count = iov_iter_count(iter);
- loff_t offset = iocb->ki_pos;
- ssize_t ret;
-
- ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block);
- if (ret < 0 && iov_iter_rw(iter) == WRITE)
- ext2_write_failed(mapping, offset + count);
- return ret;
-}
-
static int
ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
{
@@ -946,7 +961,7 @@ const struct address_space_operations ext2_aops = {
.write_begin = ext2_write_begin,
.write_end = ext2_write_end,
.bmap = ext2_bmap,
- .direct_IO = ext2_direct_IO,
+ .direct_IO = noop_direct_IO,
.writepages = ext2_writepages,
.migrate_folio = buffer_migrate_folio,
.is_partially_uptodate = block_is_partially_uptodate,
--
2.39.2
Add TRACE_IOCB_STRINGS macro which can be used in the trace point patch to
print different flag values with meaningful string output.
Tested-by: Disha Goel <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Ritesh Harjani (IBM) <[email protected]>
---
include/linux/fs.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c85916e9f7db..bdc1f7ed2aba 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -340,6 +340,20 @@ enum rw_hint {
/* can use bio alloc cache */
#define IOCB_ALLOC_CACHE (1 << 21)
+/* for use in trace events */
+#define TRACE_IOCB_STRINGS \
+ { IOCB_HIPRI, "HIPRI" }, \
+ { IOCB_DSYNC, "DSYNC" }, \
+ { IOCB_SYNC, "SYNC" }, \
+ { IOCB_NOWAIT, "NOWAIT" }, \
+ { IOCB_APPEND, "APPEND" }, \
+ { IOCB_EVENTFD, "EVENTFD"}, \
+ { IOCB_DIRECT, "DIRECT" }, \
+ { IOCB_WRITE, "WRITE" }, \
+ { IOCB_WAITQ, "WAITQ" }, \
+ { IOCB_NOIO, "NOIO" }, \
+ { IOCB_ALLOC_CACHE, "ALLOC_CACHE" }
+
struct kiocb {
struct file *ki_filp;
loff_t ki_pos;
--
2.39.2
This patch adds the trace point to ext2 direct-io apis
in fs/ext2/file.c
Here is how the output looks like
xfs_io-4099 [004] 81.431800: ext2_dio_write_iter_start: dev 7:7 ino 0xc isize 0x4000 pos 0x4000 count 4096 flags DIRECT aio 0 ret=0
xfs_io-4099 [004] 81.432002: ext2_dio_write_end_io: dev 7:7 ino 0xc isize 0x5000 pos 0x4000 count 4096 flags DIRECT aio 0 ret=0
xfs_io-4099 [004] 81.432014: ext2_dio_write_iter_dio_end: dev 7:7 ino 0xc isize 0x5000 pos 0x5000 count 0 flags DIRECT aio 0 ret=4096
aio-dio-fcntl-r-4103 [005] 81.461123: ext2_dio_write_iter_start: dev 7:7 ino 0xc isize 0x400 pos 0x200 count 512 flags DIRECT|WRITE aio 1 ret=0
aio-dio-fcntl-r-4103 [005] 81.462099: ext2_dio_write_end_io: dev 7:7 ino 0xc isize 0x400 pos 0x200 count 512 flags DIRECT|WRITE aio 1 ret=0
aio-dio-fcntl-r-4103 [005] 81.462133: ext2_dio_write_iter_dio_end: dev 7:7 ino 0xc isize 0x400 pos 0x400 count 0 flags DIRECT|WRITE aio 1 ret=512
Reported-and-tested-by: Disha Goel <[email protected]>
[Need to add CFLAGS_trace for fixing unable to find trace file problem]
Signed-off-by: Ritesh Harjani (IBM) <[email protected]>
---
fs/ext2/Makefile | 5 ++-
fs/ext2/file.c | 10 +++++-
fs/ext2/trace.c | 6 ++++
fs/ext2/trace.h | 94 ++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 113 insertions(+), 2 deletions(-)
create mode 100644 fs/ext2/trace.c
create mode 100644 fs/ext2/trace.h
diff --git a/fs/ext2/Makefile b/fs/ext2/Makefile
index 311479d864a7..8860948ef9ca 100644
--- a/fs/ext2/Makefile
+++ b/fs/ext2/Makefile
@@ -6,7 +6,10 @@
obj-$(CONFIG_EXT2_FS) += ext2.o
ext2-y := balloc.o dir.o file.o ialloc.o inode.o \
- ioctl.o namei.o super.o symlink.o
+ ioctl.o namei.o super.o symlink.o trace.o
+
+# For tracepoints to include our trace.h from tracepoint infrastructure
+CFLAGS_trace.o := -I$(src)
ext2-$(CONFIG_EXT2_FS_XATTR) += xattr.o xattr_user.o xattr_trusted.o
ext2-$(CONFIG_EXT2_FS_POSIX_ACL) += acl.o
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index 704abe0a79cb..c3e8d8cc6792 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -29,6 +29,7 @@
#include "ext2.h"
#include "xattr.h"
#include "acl.h"
+#include "trace.h"
#ifdef CONFIG_FS_DAX
static ssize_t ext2_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
@@ -170,9 +171,11 @@ static ssize_t ext2_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
struct inode *inode = file->f_mapping->host;
ssize_t ret;
+ trace_ext2_dio_read_begin(iocb, to, 0);
inode_lock_shared(inode);
ret = iomap_dio_rw(iocb, to, &ext2_iomap_ops, NULL, 0, NULL, 0);
inode_unlock_shared(inode);
+ trace_ext2_dio_read_end(iocb, to, ret);
return ret;
}
@@ -200,6 +203,7 @@ static int ext2_dio_write_end_io(struct kiocb *iocb, ssize_t size,
mark_inode_dirty(inode);
}
out:
+ trace_ext2_dio_write_endio(iocb, size, error);
return error;
}
@@ -216,7 +220,9 @@ static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
unsigned long blocksize = inode->i_sb->s_blocksize;
loff_t offset = iocb->ki_pos;
loff_t count = iov_iter_count(from);
+ ssize_t status = 0;
+ trace_ext2_dio_write_begin(iocb, from, 0);
inode_lock(inode);
ret = generic_write_checks(iocb, from);
if (ret <= 0)
@@ -244,7 +250,6 @@ static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
/* handle case for partial write and for fallback to buffered write */
if (ret >= 0 && iov_iter_count(from)) {
loff_t pos, endbyte;
- ssize_t status;
int ret2;
iocb->ki_flags &= ~IOCB_DIRECT;
@@ -270,6 +275,9 @@ static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
out_unlock:
inode_unlock(inode);
+ if (status)
+ trace_ext2_dio_write_buff_end(iocb, from, status);
+ trace_ext2_dio_write_end(iocb, from, ret);
return ret;
}
diff --git a/fs/ext2/trace.c b/fs/ext2/trace.c
new file mode 100644
index 000000000000..b01cdf6526fd
--- /dev/null
+++ b/fs/ext2/trace.c
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "ext2.h"
+#include <linux/uio.h>
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
diff --git a/fs/ext2/trace.h b/fs/ext2/trace.h
new file mode 100644
index 000000000000..37228a2c2fa6
--- /dev/null
+++ b/fs/ext2/trace.h
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM ext2
+
+#if !defined(_EXT2_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _EXT2_TRACE_H
+
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(ext2_dio_class,
+ TP_PROTO(struct kiocb *iocb, struct iov_iter *iter, ssize_t ret),
+ TP_ARGS(iocb, iter, ret),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(ino_t, ino)
+ __field(loff_t, isize)
+ __field(loff_t, pos)
+ __field(size_t, count)
+ __field(int, ki_flags)
+ __field(bool, aio)
+ __field(ssize_t, ret)
+ ),
+ TP_fast_assign(
+ __entry->dev = file_inode(iocb->ki_filp)->i_sb->s_dev;
+ __entry->ino = file_inode(iocb->ki_filp)->i_ino;
+ __entry->isize = file_inode(iocb->ki_filp)->i_size;
+ __entry->pos = iocb->ki_pos;
+ __entry->count = iov_iter_count(iter);
+ __entry->ki_flags = iocb->ki_flags;
+ __entry->aio = !is_sync_kiocb(iocb);
+ __entry->ret = ret;
+ ),
+ TP_printk("dev %d:%d ino 0x%lx isize 0x%llx pos 0x%llx count %zu flags %s aio %d ret %zd",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ __entry->isize,
+ __entry->pos,
+ __entry->count,
+ __print_flags(__entry->ki_flags, "|", TRACE_IOCB_STRINGS),
+ __entry->aio,
+ __entry->ret)
+);
+
+#define DEFINE_DIO_RW_EVENT(name) \
+DEFINE_EVENT(ext2_dio_class, name, \
+ TP_PROTO(struct kiocb *iocb, struct iov_iter *iter, ssize_t ret), \
+ TP_ARGS(iocb, iter, ret))
+DEFINE_DIO_RW_EVENT(ext2_dio_write_begin);
+DEFINE_DIO_RW_EVENT(ext2_dio_write_end);
+DEFINE_DIO_RW_EVENT(ext2_dio_write_buff_end);
+DEFINE_DIO_RW_EVENT(ext2_dio_read_begin);
+DEFINE_DIO_RW_EVENT(ext2_dio_read_end);
+
+TRACE_EVENT(ext2_dio_write_endio,
+ TP_PROTO(struct kiocb *iocb, ssize_t size, int ret),
+ TP_ARGS(iocb, size, ret),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(ino_t, ino)
+ __field(loff_t, isize)
+ __field(loff_t, pos)
+ __field(ssize_t, size)
+ __field(int, ki_flags)
+ __field(bool, aio)
+ __field(int, ret)
+ ),
+ TP_fast_assign(
+ __entry->dev = file_inode(iocb->ki_filp)->i_sb->s_dev;
+ __entry->ino = file_inode(iocb->ki_filp)->i_ino;
+ __entry->isize = file_inode(iocb->ki_filp)->i_size;
+ __entry->pos = iocb->ki_pos;
+ __entry->size = size;
+ __entry->ki_flags = iocb->ki_flags;
+ __entry->aio = !is_sync_kiocb(iocb);
+ __entry->ret = ret;
+ ),
+ TP_printk("dev %d:%d ino 0x%lx isize 0x%llx pos 0x%llx size %zd flags %s aio %d ret %d",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ __entry->isize,
+ __entry->pos,
+ __entry->size,
+ __print_flags(__entry->ki_flags, "|", TRACE_IOCB_STRINGS),
+ __entry->aio,
+ __entry->ret)
+);
+
+#endif /* _EXT2_TRACE_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE trace
+#include <trace/define_trace.h>
--
2.39.2
IOMAP_DIO_NOSYNC earlier was added for use in btrfs. But it seems for
aio dsync writes this is not useful anyway. For aio dsync case, we
we queue the request and return -EIOCBQUEUED. Now, since IOMAP_DIO_NOSYNC
doesn't let iomap_dio_complete() to call generic_write_sync(),
hence we may lose the sync write.
Hence kill this flag as it is not in use by any FS now.
Tested-by: Disha Goel <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Ritesh Harjani (IBM) <[email protected]>
---
fs/iomap/direct-io.c | 2 +-
include/linux/iomap.h | 6 ------
2 files changed, 1 insertion(+), 7 deletions(-)
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index f771001574d0..36ab1152dbea 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -541,7 +541,7 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
}
/* for data sync or sync, we need sync completion processing */
- if (iocb_is_dsync(iocb) && !(dio_flags & IOMAP_DIO_NOSYNC)) {
+ if (iocb_is_dsync(iocb)) {
dio->flags |= IOMAP_DIO_NEED_SYNC;
/*
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 0f8123504e5e..e2b836c2e119 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -377,12 +377,6 @@ struct iomap_dio_ops {
*/
#define IOMAP_DIO_PARTIAL (1 << 2)
-/*
- * The caller will sync the write if needed; do not sync it within
- * iomap_dio_rw. Overrides IOMAP_DIO_FORCE_WAIT.
- */
-#define IOMAP_DIO_NOSYNC (1 << 3)
-
ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
unsigned int dio_flags, void *private, size_t done_before);
--
2.39.2
Add iomap_dio_rw_queued and iomap_dio_complete tracepoint.
iomap_dio_rw_queued is mostly only to know that the request was queued
and -EIOCBQUEUED was returned. It is mostly iomap_dio_complete which has
all the details.
<output log>
a.out-1827 [004] 707.806763: iomap_dio_rw_queued: dev 7:7 ino 0xd size 0x1000 offset 0x1000 length 0x0
ksoftirqd/3-31 [003] 707.806968: iomap_dio_complete: dev 7:7 ino 0xd size 0x1000 offset 0x1000 flags DIRECT aio 1 error 0 ret 4096
Signed-off-by: Ritesh Harjani (IBM) <[email protected]>
---
fs/iomap/direct-io.c | 5 ++++-
fs/iomap/trace.c | 1 +
fs/iomap/trace.h | 35 +++++++++++++++++++++++++++++++++++
3 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 36ab1152dbea..cef28cfd77b7 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -130,6 +130,7 @@ ssize_t iomap_dio_complete(struct iomap_dio *dio)
if (ret > 0)
ret += dio->done_before;
+ trace_iomap_dio_complete(iocb, dio->error, ret);
kfree(dio);
return ret;
@@ -650,8 +651,10 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
*/
dio->wait_for_completion = wait_for_completion;
if (!atomic_dec_and_test(&dio->ref)) {
- if (!wait_for_completion)
+ if (!wait_for_completion) {
+ trace_iomap_dio_rw_queued(inode, iomi.pos, iomi.len);
return ERR_PTR(-EIOCBQUEUED);
+ }
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
diff --git a/fs/iomap/trace.c b/fs/iomap/trace.c
index da217246b1a9..728d5443daf5 100644
--- a/fs/iomap/trace.c
+++ b/fs/iomap/trace.c
@@ -3,6 +3,7 @@
* Copyright (c) 2019 Christoph Hellwig
*/
#include <linux/iomap.h>
+#include <linux/uio.h>
/*
* We include this last to have the helpers above available for the trace
diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h
index f6ea9540d082..9c017af93302 100644
--- a/fs/iomap/trace.h
+++ b/fs/iomap/trace.h
@@ -83,6 +83,7 @@ DEFINE_RANGE_EVENT(iomap_writepage);
DEFINE_RANGE_EVENT(iomap_release_folio);
DEFINE_RANGE_EVENT(iomap_invalidate_folio);
DEFINE_RANGE_EVENT(iomap_dio_invalidate_fail);
+DEFINE_RANGE_EVENT(iomap_dio_rw_queued);
#define IOMAP_TYPE_STRINGS \
{ IOMAP_HOLE, "HOLE" }, \
@@ -183,6 +184,40 @@ TRACE_EVENT(iomap_iter,
(void *)__entry->caller)
);
+TRACE_EVENT(iomap_dio_complete,
+ TP_PROTO(struct kiocb *iocb, int error, ssize_t ret),
+ TP_ARGS(iocb, error, ret),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(ino_t, ino)
+ __field(loff_t, isize)
+ __field(loff_t, pos)
+ __field(int, ki_flags)
+ __field(bool, aio)
+ __field(int, error)
+ __field(ssize_t, ret)
+ ),
+ TP_fast_assign(
+ __entry->dev = file_inode(iocb->ki_filp)->i_sb->s_dev;
+ __entry->ino = file_inode(iocb->ki_filp)->i_ino;
+ __entry->isize = file_inode(iocb->ki_filp)->i_size;
+ __entry->pos = iocb->ki_pos;
+ __entry->ki_flags = iocb->ki_flags;
+ __entry->aio = !is_sync_kiocb(iocb);
+ __entry->error = error;
+ __entry->ret = ret;
+ ),
+ TP_printk("dev %d:%d ino 0x%lx size 0x%llx offset 0x%llx flags %s aio %d error %d ret %zd",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->ino,
+ __entry->isize,
+ __entry->pos,
+ __print_flags(__entry->ki_flags, "|", TRACE_IOCB_STRINGS),
+ __entry->aio,
+ __entry->error,
+ __entry->ret)
+);
+
#endif /* _IOMAP_TRACE_H */
#undef TRACE_INCLUDE_PATH
--
2.39.2
Looks good based on my limited ext2 knowledge:
Reviewed-by: Christoph Hellwig <[email protected]>
On Sat, Apr 15, 2023 at 01:14:30PM +0530, Ritesh Harjani (IBM) wrote:
> Add iomap_dio_rw_queued and iomap_dio_complete tracepoint.
> iomap_dio_rw_queued is mostly only to know that the request was queued
> and -EIOCBQUEUED was returned. It is mostly iomap_dio_complete which has
> all the details.
Everything that is here looks good to me. But it seems like we lost
the _begin tracepoint?
Christoph Hellwig <[email protected]> writes:
> On Sat, Apr 15, 2023 at 01:14:30PM +0530, Ritesh Harjani (IBM) wrote:
>> Add iomap_dio_rw_queued and iomap_dio_complete tracepoint.
>> iomap_dio_rw_queued is mostly only to know that the request was queued
>> and -EIOCBQUEUED was returned. It is mostly iomap_dio_complete which has
>> all the details.
>
> Everything that is here looks good to me. But it seems like we lost
> the _begin tracepoint?
Sorry, my bad, I might have only partially understood your review
comment then. Will quickly send the next rev.
So in the next rev. will only just add a _begin tracepoint in
__iomap_dio_rw() function. Rest everything should be as is.
Right?
On Sun, Apr 16, 2023 at 05:24:25PM +0530, Ritesh Harjani wrote:
> Sorry, my bad, I might have only partially understood your review
> comment then. Will quickly send the next rev.
> So in the next rev. will only just add a _begin tracepoint in
> __iomap_dio_rw() function. Rest everything should be as is.
Thanks and sorry for beeing unclear.