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xfs: reduce stack usage of _reflink_clear_inode_flag

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The loop in _reflink_clear_inode_flag isn't necessary since we
jump out if any part of any extent is shared.  Remove the loop
and we no longer need two maps, so we can save some stack use.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reported-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Darrick J. Wong 2016-10-10 16:47:40 +11:00 committed by Dave Chinner
parent 63646fc58d
commit 024adf4870
1 changed files with 16 additions and 24 deletions
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40
fs/xfs/xfs_reflink.c
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@ -1507,7 +1507,7 @@ xfs_reflink_clear_inode_flag(
xfs_extlen_t aglen; xfs_extlen_t aglen;
xfs_agblock_t rbno; xfs_agblock_t rbno;
xfs_extlen_t rlen; xfs_extlen_t rlen;
struct xfs_bmbt_irec map[2]; struct xfs_bmbt_irec map;
int nmaps; int nmaps;
int error = 0; int error = 0;
@ -1521,37 +1521,29 @@ xfs_reflink_clear_inode_flag(
* Look for extents in the file. Skip holes, delalloc, or * Look for extents in the file. Skip holes, delalloc, or
* unwritten extents; they can't be reflinked. * unwritten extents; they can't be reflinked.
*/ */
error = xfs_bmapi_read(ip, fbno, end - fbno, map, &nmaps, 0); error = xfs_bmapi_read(ip, fbno, end - fbno, &map, &nmaps, 0);
if (error) if (error)
return error; return error;
if (nmaps == 0) if (nmaps == 0)
break; break;
if (map[0].br_startblock == HOLESTARTBLOCK || if (map.br_startblock == HOLESTARTBLOCK ||
map[0].br_startblock == DELAYSTARTBLOCK || map.br_startblock == DELAYSTARTBLOCK ||
ISUNWRITTEN(&map[0])) ISUNWRITTEN(&map))
goto next; goto next;
map[1] = map[0]; agno = XFS_FSB_TO_AGNO(mp, map.br_startblock);
while (map[1].br_blockcount) { agbno = XFS_FSB_TO_AGBNO(mp, map.br_startblock);
agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock); aglen = map.br_blockcount;
agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock);
aglen = map[1].br_blockcount;
error = xfs_reflink_find_shared(mp, agno, agbno, aglen,
&rbno, &rlen, false);
if (error)
return error;
/* Is there still a shared block here? */
if (rbno != NULLAGBLOCK)
return 0;
map[1].br_blockcount -= aglen;
map[1].br_startoff += aglen;
map[1].br_startblock += aglen;
}
error = xfs_reflink_find_shared(mp, agno, agbno, aglen,
&rbno, &rlen, false);
if (error)
return error;
/* Is there still a shared block here? */
if (rbno != NULLAGBLOCK)
return 0;
next: next:
fbno = map[0].br_startoff + map[0].br_blockcount; fbno = map.br_startoff + map.br_blockcount;
} }
/* /*