Patch "xfs: remove a racy if_bytes check in xfs_reflink_end_cow_extent" has been added to the 6.1-stable tree

This is a note to let you know that I've just added the patch titled

    xfs: remove a racy if_bytes check in xfs_reflink_end_cow_extent

to the 6.1-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:
     xfs-remove-a-racy-if_bytes-check-in-xfs_reflink_end_cow_extent.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


From [email protected] Wed Apr 30 23:33:00 2025
From: Leah Rumancik <[email protected]>
Date: Wed, 30 Apr 2025 14:26:50 -0700
Subject: xfs: remove a racy if_bytes check in xfs_reflink_end_cow_extent
To: [email protected]
Cc: [email protected], [email protected], [email protected], [email protected], Christoph Hellwig <[email protected]>, Chandan Babu R <[email protected]>, Leah Rumancik <[email protected]>
Message-ID: <[email protected]>

From: Christoph Hellwig <[email protected]>

[ Upstream commit 86de848403abda05bf9c16dcdb6bef65a8d88c41 ]

Accessing if_bytes without the ilock is racy.  Remove the initial
if_bytes == 0 check in xfs_reflink_end_cow_extent and let
ext_iext_lookup_extent fail for this case after we've taken the ilock.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: "Darrick J. Wong" <[email protected]>
Signed-off-by: Chandan Babu R <[email protected]>
Signed-off-by: Leah Rumancik <[email protected]>
Acked-by: "Darrick J. Wong" <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 fs/xfs/xfs_reflink.c |    6 ------
 1 file changed, 6 deletions(-)

--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -718,12 +718,6 @@ xfs_reflink_end_cow_extent(
 	int			nmaps;
 	int			error;
 
-	/* No COW extents?  That's easy! */
-	if (ifp->if_bytes == 0) {
-		*offset_fsb = end_fsb;
-		return 0;
-	}
-
 	resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0,
 			XFS_TRANS_RESERVE, &tp);


Patches currently in stable-queue which might be from [email protected] are

queue-6.1/xfs-revert-commit-44af6c7e59b12.patch
queue-6.1/xfs-make-the-seq-argument-to-xfs_bmapi_convert_delalloc-optional.patch
queue-6.1/xfs-check-opcode-and-iovec-count-match-in-xlog_recover_attri_commit_pass2.patch
queue-6.1/xfs-allow-symlinks-with-short-remote-targets.patch
queue-6.1/xfs-match-lock-mode-in-xfs_buffered_write_iomap_begin.patch
queue-6.1/xfs-require-xfs_sb_feat_incompat_log_xattrs-for-attr-log-intent-item-recovery.patch
queue-6.1/xfs-allow-unlinked-symlinks-and-dirs-with-zero-size.patch
queue-6.1/xfs-restrict-when-we-try-to-align-cow-fork-delalloc-to-cowextsz-hints.patch
queue-6.1/xfs-fix-xfs_bmap_add_extent_delay_real-for-partial-conversions.patch
queue-6.1/xfs-validate-recovered-name-buffers-when-recovering-xattr-items.patch
queue-6.1/xfs-make-xfs_bmapi_convert_delalloc-to-allocate-the-target-offset.patch
queue-6.1/xfs-convert-delayed-extents-to-unwritten-when-zeroing-post-eof-blocks.patch
queue-6.1/xfs-fix-freeing-speculative-preallocations-for-preallocated-files.patch
queue-6.1/xfs-make-sure-sb_fdblocks-is-non-negative.patch
queue-6.1/xfs-remove-a-racy-if_bytes-check-in-xfs_reflink_end_cow_extent.patch
queue-6.1/xfs-fix-error-returns-from-xfs_bmapi_write.patch