From fba3e594ef0ad911fa8f559732d588172f212d71 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 28 Nov 2016 14:57:42 +1100 Subject: [PATCH] xfs: always succeed when deduping zero bytes It turns out that btrfs and xfs had differing interpretations of what to do when the dedupe length is zero. Change xfs to follow btrfs' semantics so that the userland interface is consistent. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/xfs_reflink.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 56372bee08c5..c58371fde08d 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -1317,8 +1317,14 @@ xfs_reflink_remap_range( goto out_unlock; } - if (len == 0) + /* Zero length dedupe exits immediately; reflink goes to EOF. */ + if (len == 0) { + if (is_dedupe) { + ret = 0; + goto out_unlock; + } len = isize - pos_in; + } /* Ensure offsets don't wrap and the input is inside i_size */ if (pos_in + len < pos_in || pos_out + len < pos_out || -- 2.20.1