ceph: kill ceph_empty_snapc

ceph_empty_snapc->num_snaps == 0 at all times.  Passing such a snapc to
ceph_osdc_alloc_request() (possibly through ceph_osdc_new_request()) is
equivalent to passing NULL, as ceph_osdc_alloc_request() uses it only
for sizing the request message.

Further, in all four cases the subsequent ceph_osdc_build_request() is
passed NULL for snapc, meaning that 0 is encoded for seq and num_snaps
and making ceph_empty_snapc entirely useless.  The two cases where it
actually mattered were removed in commits 860560904962 ("ceph: avoid
sending unnessesary FLUSHSNAP message") and 23078637e054 ("ceph: fix
queuing inode to mdsdir's snaprealm").

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by:  Yan, Zheng <zyan@redhat.com>

1 files changed, 0 insertions, 16 deletions

diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index 4aa7122a8d38..9caaa7ffc93f 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -296,8 +296,6 @@ static int cmpu64_rev(const void *a, const void *b)
 }
 
 
-struct ceph_snap_context *ceph_empty_snapc;
-
 /*
  * build the snap context for a given realm.
  */
@@ -987,17 +985,3 @@ out:
 		up_write(&mdsc->snap_rwsem);
 	return;
 }
-
-int __init ceph_snap_init(void)
-{
-	ceph_empty_snapc = ceph_create_snap_context(0, GFP_NOFS);
-	if (!ceph_empty_snapc)
-		return -ENOMEM;
-	ceph_empty_snapc->seq = 1;
-	return 0;
-}
-
-void ceph_snap_exit(void)
-{
-	ceph_put_snap_context(ceph_empty_snapc);
-}