tree 4ce8aee02deb8ed2d37ef08fe7b2bf2ef66eec24
parent c3a468915a384c0015263edd9b7263775599a323
author Filipe Manana <fdmanana@gmail.com> 1394830501 +0000
committer Chris Mason <clm@fb.com> 1395360928 -0700

Btrfs: fix race when updating existing ref head

While we update an existing ref head's extent_op, we're not holding
its spinlock, so while we're updating its extent_op contents (key,
flags) we can have a task running __btrfs_run_delayed_refs() that
holds the ref head's lock and sets its extent_op to NULL right after
the task updating the ref head just checked its extent_op was not NULL.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>