4.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
commit 3af423b03435c81036fa710623d3ae92fbe346a3 upstream.
When we perform an finsert/fcollapse operation, cancel all the CoW
extents for the affected file offset range so that they don't end up
pointing to the wrong blocks.
Reported-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/xfs_bmap_util.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1459,7 +1459,19 @@ xfs_shift_file_space(
return error;
/*
- * The extent shiting code works on extent granularity. So, if
+ * Clean out anything hanging around in the cow fork now that
+ * we've flushed all the dirty data out to disk to avoid having
+ * CoW extents at the wrong offsets.
+ */
+ if (xfs_is_reflink_inode(ip)) {
+ error = xfs_reflink_cancel_cow_range(ip, offset, NULLFILEOFF,
+ true);
+ if (error)
+ return error;
+ }
+
+ /*
+ * The extent shifting code works on extent granularity. So, if
* stop_fsb is not the starting block of extent, we need to split
* the extent at stop_fsb.
*/