xfs: iterate backwards in xfs_reflink_cancel_cow_blocks

Match the iteration order for extent deletion in the truncate and
reflink I/O completion path.

This also happens to make implementing the new incore extent list
a lot easier.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Christoph Hellwig 2017-11-03 10:34:44 -07:00 committed by Darrick J. Wong
parent b2b1712a64
commit 41caabd0ab
1 changed files with 12 additions and 4 deletions

View File

@ -569,12 +569,20 @@ xfs_reflink_cancel_cow_blocks(
if (!xfs_is_reflink_inode(ip))
return 0;
if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &icur, &got))
if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got))
return 0;
while (got.br_startoff < end_fsb) {
/* Walk backwards until we're out of the I/O range... */
while (got.br_startoff + got.br_blockcount > offset_fsb) {
del = got;
xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb);
/* Extent delete may have bumped ext forward */
if (!del.br_blockcount) {
xfs_iext_prev(ifp, &icur);
goto next_extent;
}
trace_xfs_reflink_cancel_cow(ip, &del);
if (isnullstartblock(del.br_startblock)) {
@ -612,8 +620,8 @@ xfs_reflink_cancel_cow_blocks(
/* Remove the mapping from the CoW fork. */
xfs_bmap_del_extent_cow(ip, &icur, &got, &del);
}
if (!xfs_iext_next_extent(ifp, &icur, &got))
next_extent:
if (!xfs_iext_get_extent(ifp, &icur, &got))
break;
}