On 11/19/20 5:39 PM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> 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>
> ---
> fs/xfs/libxfs/xfs_rmap_btree.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c
> index 577a66381327..beb81c84a937 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;
>
