xfs: don't create overlapping extents in xfs_bmap_add_extent_delay_real

Source kernel commit: 1bfd7618cbf2de630c845f60f5370671c2cd1c5d

Two cases in xfs_bmap_add_extent_delay_real currently insert a new
extent before updating the existing one that is being split.  While
this works fine with a simple extent list, a more complex tree can't
easily cope with overlapping extent.  Reshuffle the code a bit to update
the slot of the existing delalloc extent to the new real extent before
inserting the shortened delalloc extent before or after it.  This
avoids the overlapping extents while still allowing to update the
br_startblock field of the delalloc extent with the updated indirect
block reservation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c
index 8c0a9a584ff74b51d071cfc088a78b33aa0b67bf..d91097ffab25a052f07f4a54fc27c7bc99d3e460 100644 (file)
--- a/libxfs/xfs_bmap.c
+++ b/libxfs/xfs_bmap.c
@@ -1782,7 +1782,7 @@ xfs_bmap_add_extent_delay_real(
                 * Filling in the first part of a previous delayed allocation.
                 * The left neighbor is not contiguous.
                 */
-               xfs_iext_insert(bma->ip, bma->idx, 1, new, state);
+               xfs_iext_update_extent(bma->ip, state, bma->idx, new);
                (*nextents)++;
                if (bma->cur == NULL)
                        rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
@@ -1815,7 +1815,7 @@ xfs_bmap_add_extent_delay_real(
                PREV.br_startoff = new_endoff;
                PREV.br_blockcount = temp;
                PREV.br_startblock = nullstartblock(da_new);
-               xfs_iext_update_extent(bma->ip, state, bma->idx + 1, &PREV);
+               xfs_iext_insert(bma->ip, bma->idx + 1, 1, &PREV, state);
                break;
 
        case BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
@@ -1858,7 +1858,7 @@ xfs_bmap_add_extent_delay_real(
                 * Filling in the last part of a previous delayed allocation.
                 * The right neighbor is not contiguous.
                 */
-               xfs_iext_insert(bma->ip, bma->idx + 1, 1, new, state);
+               xfs_iext_update_extent(bma->ip, state, bma->idx, new);
                (*nextents)++;
                if (bma->cur == NULL)
                        rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
@@ -1890,7 +1890,7 @@ xfs_bmap_add_extent_delay_real(
 
                PREV.br_startblock = nullstartblock(da_new);
                PREV.br_blockcount = temp;
-               xfs_iext_update_extent(bma->ip, state, bma->idx, &PREV);
+               xfs_iext_insert(bma->ip, bma->idx, 1, &PREV, state);
 
                bma->idx++;
                break;