nfsd: allow open state ids to be revoked and then freed

Revoking state through 'unlock_filesystem' now revokes any open states
found.  When the stateids are then freed by the client, the revoked
stateids will be cleaned up correctly.

Possibly the related lock states should be revoked too, but a
subsequent patch will do that for all lock state on the superblock.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4state.c

@@ -1717,7 +1717,7 @@ void nfsd4_revoke_states(struct net *net, struct super_block *sb)
 	unsigned int idhashval;
 	unsigned int sc_types;
 
-	sc_types = SC_TYPE_LOCK;
+	sc_types = SC_TYPE_OPEN | SC_TYPE_LOCK;
 
 	spin_lock(&nn->client_lock);
 	for (idhashval = 0; idhashval < CLIENT_HASH_MASK; idhashval++) {
@@ -1732,6 +1732,22 @@ void nfsd4_revoke_states(struct net *net, struct super_block *sb)
 
 				spin_unlock(&nn->client_lock);
 				switch (stid->sc_type) {
+				case SC_TYPE_OPEN:
+					stp = openlockstateid(stid);
+					mutex_lock_nested(&stp->st_mutex,
+							  OPEN_STATEID_MUTEX);
+
+					spin_lock(&clp->cl_lock);
+					if (stid->sc_status == 0) {
+						stid->sc_status |=
+							SC_STATUS_ADMIN_REVOKED;
+						atomic_inc(&clp->cl_admin_revoked);
+						spin_unlock(&clp->cl_lock);
+						release_all_access(stp);
+					} else
+						spin_unlock(&clp->cl_lock);
+					mutex_unlock(&stp->st_mutex);
+					break;
 				case SC_TYPE_LOCK:
 					stp = openlockstateid(stid);
 					mutex_lock_nested(&stp->st_mutex,
@@ -4663,6 +4679,13 @@ static void nfsd4_drop_revoked_stid(struct nfs4_stid *s)
 	bool unhashed;
 
 	switch (s->sc_type) {
+	case SC_TYPE_OPEN:
+		stp = openlockstateid(s);
+		if (unhash_open_stateid(stp, &reaplist))
+			put_ol_stateid_locked(stp, &reaplist);
+		spin_unlock(&cl->cl_lock);
+		free_ol_stateid_reaplist(&reaplist);
+		break;
 	case SC_TYPE_LOCK:
 		stp = openlockstateid(s);
 		unhashed = unhash_lock_stateid(stp);