xfs: treat idx as a cursor in xfs_bmap_add_extent_delay_real

Stop poking before and after the index and just increment or decrement
it while doing our operations on it to prepare for a new extent list
implementation.

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>

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index e1d61fa..c0216e9 100644 (file)
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -1648,12 +1648,13 @@ xfs_bmap_add_extent_delay_real(
                 * Filling in all of a previously delayed allocation extent.
                 * The left and right neighbors are both contiguous with new.
                 */
-               bma->idx--;
                LEFT.br_blockcount += PREV.br_blockcount + RIGHT.br_blockcount;
-               xfs_iext_update_extent(bma->ip, state, bma->idx, &LEFT);
 
-               xfs_iext_remove(bma->ip, bma->idx + 1, 2, state);
+               xfs_iext_remove(bma->ip, bma->idx, 2, state);
+               bma->idx--;
+               xfs_iext_update_extent(bma->ip, state, bma->idx, &LEFT);
                (*nextents)--;
+
                if (bma->cur == NULL)
                        rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
                else {
@@ -1681,13 +1682,13 @@ xfs_bmap_add_extent_delay_real(
                 * Filling in all of a previously delayed allocation extent.
                 * The left neighbor is contiguous, the right is not.
                 */
-               bma->idx--;
-
                old = LEFT;
                LEFT.br_blockcount += PREV.br_blockcount;
+
+               xfs_iext_remove(bma->ip, bma->idx, 1, state);
+               bma->idx--;
                xfs_iext_update_extent(bma->ip, state, bma->idx, &LEFT);
 
-               xfs_iext_remove(bma->ip, bma->idx + 1, 1, state);
                if (bma->cur == NULL)
                        rval = XFS_ILOG_DEXT;
                else {
@@ -1709,9 +1710,12 @@ xfs_bmap_add_extent_delay_real(
                 */
                PREV.br_startblock = new->br_startblock;
                PREV.br_blockcount += RIGHT.br_blockcount;
+
+               bma->idx++;
+               xfs_iext_remove(bma->ip, bma->idx, 1, state);
+               bma->idx--;
                xfs_iext_update_extent(bma->ip, state, bma->idx, &PREV);
 
-               xfs_iext_remove(bma->ip, bma->idx + 1, 1, state);
                if (bma->cur == NULL)
                        rval = XFS_ILOG_DEXT;
                else {
@@ -1763,12 +1767,14 @@ xfs_bmap_add_extent_delay_real(
                                startblockval(PREV.br_startblock));
 
                LEFT.br_blockcount += new->br_blockcount;
-               xfs_iext_update_extent(bma->ip, state, bma->idx - 1, &LEFT);
 
                PREV.br_blockcount = temp;
                PREV.br_startoff += new->br_blockcount;
                PREV.br_startblock = nullstartblock(da_new);
+
                xfs_iext_update_extent(bma->ip, state, bma->idx, &PREV);
+               bma->idx--;
+               xfs_iext_update_extent(bma->ip, state, bma->idx, &LEFT);
 
                if (bma->cur == NULL)
                        rval = XFS_ILOG_DEXT;
@@ -1783,7 +1789,6 @@ xfs_bmap_add_extent_delay_real(
                                goto done;
                }
 
-               bma->idx--;
                break;
 
        case BMAP_LEFT_FILLING:
@@ -1836,7 +1841,6 @@ xfs_bmap_add_extent_delay_real(
                RIGHT.br_startoff = new->br_startoff;
                RIGHT.br_startblock = new->br_startblock;
                RIGHT.br_blockcount += new->br_blockcount;
-               xfs_iext_update_extent(bma->ip, state, bma->idx + 1, &RIGHT);
 
                if (bma->cur == NULL)
                        rval = XFS_ILOG_DEXT;
@@ -1857,9 +1861,10 @@ xfs_bmap_add_extent_delay_real(
 
                PREV.br_blockcount = temp;
                PREV.br_startblock = nullstartblock(da_new);
-               xfs_iext_update_extent(bma->ip, state, bma->idx, &PREV);
 
+               xfs_iext_update_extent(bma->ip, state, bma->idx, &PREV);
                bma->idx++;
+               xfs_iext_update_extent(bma->ip, state, bma->idx, &RIGHT);
                break;
 
        case BMAP_RIGHT_FILLING: