NFSv4: Don't try to CLOSE if the stateid 'other' field has changed

If the stateid is no longer recognised on the server, either due to a
restart, or due to a competing CLOSE call, then we do not have to
retry. Any open contexts that triggered a reopen of the file, will
also act as triggers for any CLOSE for the updated stateids.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index feb084b..9721b74 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -462,6 +462,8 @@ extern int nfs4_select_rw_stateid(struct nfs4_state *, fmode_t,
 		struct rpc_cred **);
 extern bool nfs4_refresh_open_stateid(nfs4_stateid *dst,
 		struct nfs4_state *state);
+extern bool nfs4_copy_open_stateid(nfs4_stateid *dst,
+		struct nfs4_state *state);
 
 extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask);
 extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task);