tree 05a75dfc1ddf4729405f9cb6ce2f405b8e47791e
parent 860560904962d08fd38666207c910065fe53e074
author Yan, Zheng <zyan@redhat.com> 1430473756 +0800
committer Ilya Dryomov <idryomov@gmail.com> 1435222168 +0300

ceph: take snap_rwsem when accessing snap realm's cached_context

When ceph inode's i_head_snapc is NULL, __ceph_mark_dirty_caps()
accesses snap realm's cached_context. So we need take read lock
of snap_rwsem.

Signed-off-by: Yan, Zheng <zyan@redhat.com>