xfs: handle racy AIO in xfs_reflink_end_cow
authorChristoph Hellwig <hch@lst.de>
Tue, 3 Oct 2017 15:58:33 +0000 (08:58 -0700)
committerDarrick J. Wong <darrick.wong@oracle.com>
Wed, 4 Oct 2017 04:27:55 +0000 (21:27 -0700)
commite12199f85d0ad1b04ce6c425ad93cd847fe930bb
treea4d96867b24d45f6e627b72f9d804ed2cb3e92b1
parent52bfcdd7adbc26639bc7b2356ab9a3f5dad68ad6
 xfs: handle racy AIO in xfs_reflink_end_cow

If we got two AIO writes into a COW area the second one might not have any
COW extents left to convert.  Handle that case gracefully instead of
triggering an assert or accessing beyond the bounds of the extent list.

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>
fs/xfs/xfs_reflink.c