Patch "xfs: revert "xfs: fix rmap key and record comparison functions"" has been added to the 5.9-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    xfs: revert "xfs: fix rmap key and record comparison functions"

to the 5.9-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-revert-xfs-fix-rmap-key-and-record-comparison-fu.patch
and it can be found in the queue-5.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 3ac3a50ac1d382b8f5b18bc3dcd54d94225ff4a9
Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Date:   Thu Nov 19 15:17:50 2020 -0800

    xfs: revert "xfs: fix rmap key and record comparison functions"
    
    [ Upstream commit eb8409071a1d47e3593cfe077107ac46853182ab ]
    
    This reverts commit 6ff646b2ceb0eec916101877f38da0b73e3a5b7f.
    
    Your maintainer committed a major braino in the rmap code by adding the
    attr fork, bmbt, and unwritten extent usage bits into rmap record key
    comparisons.  While XFS uses the usage bits *in the rmap records* for
    cross-referencing metadata in xfs_scrub and xfs_repair, it only needs
    the owner and offset information to distinguish between reverse mappings
    of the same physical extent into the data fork of a file at multiple
    offsets.  The other bits are not important for key comparisons for index
    lookups, and never have been.
    
    Eric Sandeen reports that this causes regressions in generic/299, so
    undo this patch before it does more damage.
    
    Reported-by: Eric Sandeen <sandeen@xxxxxxxxxxx>
    Fixes: 6ff646b2ceb0 ("xfs: fix rmap key and record comparison functions")
    Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
    Reviewed-by: Eric Sandeen <sandeen@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c
index 577a66381327c..beb81c84a9375 100644
--- a/fs/xfs/libxfs/xfs_rmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rmap_btree.c
@@ -243,8 +243,8 @@ xfs_rmapbt_key_diff(
 	else if (y > x)
 		return -1;
 
-	x = be64_to_cpu(kp->rm_offset);
-	y = xfs_rmap_irec_offset_pack(rec);
+	x = XFS_RMAP_OFF(be64_to_cpu(kp->rm_offset));
+	y = rec->rm_offset;
 	if (x > y)
 		return 1;
 	else if (y > x)
@@ -275,8 +275,8 @@ xfs_rmapbt_diff_two_keys(
 	else if (y > x)
 		return -1;
 
-	x = be64_to_cpu(kp1->rm_offset);
-	y = be64_to_cpu(kp2->rm_offset);
+	x = XFS_RMAP_OFF(be64_to_cpu(kp1->rm_offset));
+	y = XFS_RMAP_OFF(be64_to_cpu(kp2->rm_offset));
 	if (x > y)
 		return 1;
 	else if (y > x)
@@ -390,8 +390,8 @@ xfs_rmapbt_keys_inorder(
 		return 1;
 	else if (a > b)
 		return 0;
-	a = be64_to_cpu(k1->rmap.rm_offset);
-	b = be64_to_cpu(k2->rmap.rm_offset);
+	a = XFS_RMAP_OFF(be64_to_cpu(k1->rmap.rm_offset));
+	b = XFS_RMAP_OFF(be64_to_cpu(k2->rmap.rm_offset));
 	if (a <= b)
 		return 1;
 	return 0;
@@ -420,8 +420,8 @@ xfs_rmapbt_recs_inorder(
 		return 1;
 	else if (a > b)
 		return 0;
-	a = be64_to_cpu(r1->rmap.rm_offset);
-	b = be64_to_cpu(r2->rmap.rm_offset);
+	a = XFS_RMAP_OFF(be64_to_cpu(r1->rmap.rm_offset));
+	b = XFS_RMAP_OFF(be64_to_cpu(r2->rmap.rm_offset));
 	if (a <= b)
 		return 1;
 	return 0;