Merge git://git.linux-nfs.org/pub/linux/nfs-2.6

* git://git.linux-nfs.org/pub/linux/nfs-2.6: (118 commits)
  NFSv4: Iterate through all nfs_clients when the server recalls a delegation
  NFSv4: Deal more correctly with duplicate delegations
  NFS: Fix a potential race between umount and nfs_access_cache_shrinker()
  NFS: Add an asynchronous delegreturn operation for use in nfs_clear_inode
  nfs: convert NFS_*(inode) helpers to static inline
  nfs: obliterate NFS_FLAGS macro
  NFS: Address memory leaks in the NFS client mount option parser
  nfs4: allow nfsv4 acls on non-regular-files
  NFS: Optimise away the sigmask code in aio/dio reads and writes
  SUNRPC: Don't bother changing the sigmask for asynchronous RPC calls
  SUNRPC: rpcb_getport_sync() passes incorrect address size to rpc_create()
  SUNRPC: Clean up block comment preceding rpcb_getport_sync()
  SUNRPC: Use appropriate argument types in rpcb client
  SUNRPC: rpcb_getport_sync() should use built-in hostname generator
  SUNRPC: Clean up functions that free address_strings array
  NFS: NFS version number is unsigned
  NLM: Fix a bogus 'return' in nlmclnt_rpc_release
  NLM: Introduce an arguments structure for nlmclnt_init()
  NLM/NFS: Use cached nlm_host when calling nlmclnt_proc()
  NFS: Invoke nlmclnt_init during NFS mount processing
  ...
diff --git a/block/as-iosched.c b/block/as-iosched.c
index b201d16..9603684 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -1275,9 +1275,13 @@
 			 * Don't copy here but swap, because when anext is
 			 * removed below, it must contain the unused context
 			 */
-			double_spin_lock(&rioc->lock, &nioc->lock, rioc < nioc);
-			swap_io_context(&rioc, &nioc);
-			double_spin_unlock(&rioc->lock, &nioc->lock, rioc < nioc);
+			if (rioc != nioc) {
+				double_spin_lock(&rioc->lock, &nioc->lock,
+								rioc < nioc);
+				swap_io_context(&rioc, &nioc);
+				double_spin_unlock(&rioc->lock, &nioc->lock,
+								rioc < nioc);
+			}
 		}
 	}