NFSv4: Fix open recovery

NFSv4 open recovery is currently broken: since we do not clear the
state->flags states before attempting recovery, we end up with the
'can_open_cached()' function triggering. This again leads to no OPEN call
being put on the wire.
Reported-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

fs/nfs/nfs4proc.c

@@ -1118,6 +1118,7 @@ static int nfs4_open_recover(struct nfs4_opendata *opendata, struct nfs4_state *
 	clear_bit(NFS_DELEGATED_STATE, &state->flags);
 	smp_rmb();
 	if (state->n_rdwr != 0) {
+		clear_bit(NFS_O_RDWR_STATE, &state->flags);
 		ret = nfs4_open_recover_helper(opendata, FMODE_READ|FMODE_WRITE, &newstate);
 		if (ret != 0)
 			return ret;
@@ -1125,6 +1126,7 @@ static int nfs4_open_recover(struct nfs4_opendata *opendata, struct nfs4_state *
 			return -ESTALE;
 	}
 	if (state->n_wronly != 0) {
+		clear_bit(NFS_O_WRONLY_STATE, &state->flags);
 		ret = nfs4_open_recover_helper(opendata, FMODE_WRITE, &newstate);
 		if (ret != 0)
 			return ret;
@@ -1132,6 +1134,7 @@ static int nfs4_open_recover(struct nfs4_opendata *opendata, struct nfs4_state *
 			return -ESTALE;
 	}
 	if (state->n_rdonly != 0) {
+		clear_bit(NFS_O_RDONLY_STATE, &state->flags);
 		ret = nfs4_open_recover_helper(opendata, FMODE_READ, &newstate);
 		if (ret != 0)
 			return ret;