From 41caabd0ab997bcfa9a4822fac32c0803f1cc3df Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 3 Nov 2017 10:34:44 -0700 Subject: [PATCH] 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 Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_reflink.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index d86c4378facf..cf976ed65260 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -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; }