[PATCH] xfs: bad assertion for delalloc an extent that start at i_size

[PATCH] xfs: bad assertion for delalloc an extent that start at i_size

[Zorro Lang]

By run fsstress long enough time enough in RHEL-7, I find an
assertion failure (harder to reproduce on linux-4.11, but problem
is still there):

  XFS: Assertion failed: (iflags & BMV_IF_DELALLOC) != 0, file: fs/xfs/xfs_bmap_util.c

The assertion is in xfs_getbmap() funciton:

  if (map[i].br_startblock == DELAYSTARTBLOCK &&
-->   map[i].br_startoff <= XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
          ASSERT((iflags & BMV_IF_DELALLOC) != 0);

When map[i].br_startoff == XFS_B_TO_FSB(mp, XFS_ISIZE(ip)), the
startoff is just at EOF. But we only need to make sure delalloc
extents that are within EOF, not include EOF.

Signed-off-by: Zorro Lang <zlang@redhat.com>
---
 fs/xfs/xfs_bmap_util.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 8795e9c..a6d83ea 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -713,7 +713,7 @@ xfs_getbmap(
 			 * extents.
 			 */
 			if (map[i].br_startblock == DELAYSTARTBLOCK &&
-			    map[i].br_startoff <= XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
+			    map[i].br_startoff < XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
 				ASSERT((iflags & BMV_IF_DELALLOC) != 0);
 
                         if (map[i].br_startblock == HOLESTARTBLOCK &&
-- 
2.7.4

Re: [PATCH] xfs: bad assertion for delalloc an extent that start at i_size

[Brian Foster]

On Mon, May 15, 2017 at 06:21:50PM +0800, Zorro Lang wrote:
> By run fsstress long enough time enough in RHEL-7, I find an
> assertion failure (harder to reproduce on linux-4.11, but problem
> is still there):
> 
>   XFS: Assertion failed: (iflags & BMV_IF_DELALLOC) != 0, file: fs/xfs/xfs_bmap_util.c
> 
> The assertion is in xfs_getbmap() funciton:
> 
>   if (map[i].br_startblock == DELAYSTARTBLOCK &&
> -->   map[i].br_startoff <= XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
>           ASSERT((iflags & BMV_IF_DELALLOC) != 0);
> 
> When map[i].br_startoff == XFS_B_TO_FSB(mp, XFS_ISIZE(ip)), the
> startoff is just at EOF. But we only need to make sure delalloc
> extents that are within EOF, not include EOF.
> 
> Signed-off-by: Zorro Lang <zlang@redhat.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/xfs_bmap_util.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
> index 8795e9c..a6d83ea 100644
> --- a/fs/xfs/xfs_bmap_util.c
> +++ b/fs/xfs/xfs_bmap_util.c
> @@ -713,7 +713,7 @@ xfs_getbmap(
>  			 * extents.
>  			 */
>  			if (map[i].br_startblock == DELAYSTARTBLOCK &&
> -			    map[i].br_startoff <= XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
> +			    map[i].br_startoff < XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
>  				ASSERT((iflags & BMV_IF_DELALLOC) != 0);
>  
>                          if (map[i].br_startblock == HOLESTARTBLOCK &&
> -- 
> 2.7.4
> 
> --
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