ceph: use empty snap context for uninline_data and get_pool_perm
Cached_context in ceph_snap_realm is directly accessed by
uninline_data() and get_pool_perm(). This is racy in theory.
both uninline_data() and get_pool_perm() do not modify existing
object, they only create new object. So we can pass the empty
snap context to them. Unlike cached_context in ceph_snap_realm,
we do not need to protect the empty snap context.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 18b917c..b182fd7 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -692,6 +692,7 @@
/* snap.c */
+extern struct ceph_snap_context *ceph_empty_snapc;
struct ceph_snap_realm *ceph_lookup_snap_realm(struct ceph_mds_client *mdsc,
u64 ino);
extern void ceph_get_snap_realm(struct ceph_mds_client *mdsc,