This is a note to let you know that I've just added the patch titled
iomap: iomap that extends beyond EOF should be marked dirty
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iomap-iomap-that-extends-beyond-eof-should-be-marked-dirty.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Sep 21 10:59:33 AM CEST 2022
From: Chandan Babu R <chandan.babu@xxxxxxxxxx>
Date: Wed, 21 Sep 2022 08:53:37 +0530
Subject: iomap: iomap that extends beyond EOF should be marked dirty
To: gregkh@xxxxxxxxxxxxxxxxxxx
Cc: sashal@xxxxxxxxxx, mcgrof@xxxxxxxxxx, linux-xfs@xxxxxxxxxxxxxxx, stable@xxxxxxxxxxxxxxx, djwong@xxxxxxxxxx, chandan.babu@xxxxxxxxxx, amir73il@xxxxxxxxx, leah.rumancik@xxxxxxxxx
Message-ID: <20220921032352.307699-3-chandan.babu@xxxxxxxxxx>
From: Chandan Babu R <chandan.babu@xxxxxxxxxx>
From: Dave Chinner <dchinner@xxxxxxxxxx>
commit 7684e2c4384d5d1f884b01ab8bff2369e4db0bff upstream.
When doing a direct IO that spans the current EOF, and there are
written blocks beyond EOF that extend beyond the current write, the
only metadata update that needs to be done is a file size extension.
However, we don't mark such iomaps as IOMAP_F_DIRTY to indicate that
there is IO completion metadata updates required, and hence we may
fail to correctly sync file size extensions made in IO completion
when O_DSYNC writes are being used and the hardware supports FUA.
Hence when setting IOMAP_F_DIRTY, we need to also take into account
whether the iomap spans the current EOF. If it does, then we need to
mark it dirty so that IO completion will call generic_write_sync()
to flush the inode size update to stable storage correctly.
Fixes: 3460cac1ca76 ("iomap: Use FUA for pure data O_DSYNC DIO writes")
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
[darrick: removed the ext4 part; they'll handle it separately]
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Acked-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Chandan Babu R <chandan.babu@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/xfs_iomap.c | 7 +++++++
include/linux/iomap.h | 2 ++
2 files changed, 9 insertions(+)
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -1055,6 +1055,13 @@ xfs_file_iomap_begin(
trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap);
out_finish:
+ /*
+ * 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;
return xfs_bmbt_to_iomap(ip, iomap, &imap, shared);
out_found:
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -32,6 +32,8 @@ struct vm_fault;
*
* IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access
* written data and requires fdatasync to commit them to persistent storage.
+ * This needs to take into account metadata changes that *may* be made at IO
+ * completion, such as file size updates from direct IO.
*/
#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
#define IOMAP_F_DIRTY 0x02 /* uncommitted metadata */
Patches currently in stable-queue which might be from chandan.babu@xxxxxxxxxx are
queue-5.4/xfs-refactor-agfl-length-computation-function.patch
queue-5.4/xfs-use-bitops-interface-for-buf-log-item-ail-flag-check.patch
queue-5.4/maintainers-add-chandan-as-xfs-maintainer-for-5.4.y.patch
queue-5.4/xfs-split-the-sunit-parameter-update-into-two-parts.patch
queue-5.4/xfs-slightly-tweak-an-assert-in-xfs_fs_map_blocks.patch
queue-5.4/xfs-stabilize-insert-range-start-boundary-to-avoid-cow-writeback-race.patch
queue-5.4/iomap-iomap-that-extends-beyond-eof-should-be-marked-dirty.patch
queue-5.4/xfs-constify-the-buffer-pointer-arguments-to-error-functions.patch
queue-5.4/xfs-attach-dquots-and-reserve-quota-blocks-during-unwritten-conversion.patch
queue-5.4/xfs-range-check-ri_cnt-when-recovering-log-items.patch
queue-5.4/xfs-fix-deadlock-between-agi-and-agf-when-target_ip-exists-in-xfs_rename.patch
queue-5.4/xfs-replace-eio-with-efscorrupted-for-corrupt-metadata.patch
queue-5.4/xfs-convert-eio-to-efscorrupted-when-log-contents-are-invalid.patch
queue-5.4/xfs-add-missing-assert-in-xfs_fsmap_owner_from_rmap.patch
queue-5.4/xfs-always-log-corruption-errors.patch
queue-5.4/xfs-fix-some-memory-leaks-in-log-recovery.patch
queue-5.4/xfs-don-t-commit-sunit-swidth-updates-to-disk-if-that-would-cause-repair-failures.patch
