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

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

As there is already support for revoking delegations, we build on that
for admin-revoking.
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

@@ -1335,9 +1335,12 @@ unhash_delegation_locked(struct nfs4_delegation *dp, unsigned short statusmask)
 	if (!delegation_hashed(dp))
 		return false;
 
-	if (dp->dl_stid.sc_client->cl_minorversion == 0)
+	if (statusmask == SC_STATUS_REVOKED &&
+	    dp->dl_stid.sc_client->cl_minorversion == 0)
 		statusmask = SC_STATUS_CLOSED;
 	dp->dl_stid.sc_status |= statusmask;
+	if (statusmask & SC_STATUS_ADMIN_REVOKED)
+		atomic_inc(&dp->dl_stid.sc_client->cl_admin_revoked);
 
 	/* Ensure that deleg break won't try to requeue it */
 	++dp->dl_time;
@@ -1368,7 +1371,8 @@ static void revoke_delegation(struct nfs4_delegation *dp)
 
 	trace_nfsd_stid_revoke(&dp->dl_stid);
 
-	if (dp->dl_stid.sc_status & SC_STATUS_REVOKED) {
+	if (dp->dl_stid.sc_status &
+	    (SC_STATUS_REVOKED | SC_STATUS_ADMIN_REVOKED)) {
 		spin_lock(&clp->cl_lock);
 		refcount_inc(&dp->dl_stid.sc_count);
 		list_add(&dp->dl_recall_lru, &clp->cl_revoked);
@@ -1717,7 +1721,7 @@ void nfsd4_revoke_states(struct net *net, struct super_block *sb)
 	unsigned int idhashval;
 	unsigned int sc_types;
 
-	sc_types = SC_TYPE_OPEN | SC_TYPE_LOCK;
+	sc_types = SC_TYPE_OPEN | SC_TYPE_LOCK | SC_TYPE_DELEG;
 
 	spin_lock(&nn->client_lock);
 	for (idhashval = 0; idhashval < CLIENT_HASH_MASK; idhashval++) {
@@ -1729,6 +1733,7 @@ void nfsd4_revoke_states(struct net *net, struct super_block *sb)
 								  sc_types);
 			if (stid) {
 				struct nfs4_ol_stateid *stp;
+				struct nfs4_delegation *dp;
 
 				spin_unlock(&nn->client_lock);
 				switch (stid->sc_type) {
@@ -1774,6 +1779,16 @@ void nfsd4_revoke_states(struct net *net, struct super_block *sb)
 						spin_unlock(&clp->cl_lock);
 					mutex_unlock(&stp->st_mutex);
 					break;
+				case SC_TYPE_DELEG:
+					dp = delegstateid(stid);
+					spin_lock(&state_lock);
+					if (!unhash_delegation_locked(
+						    dp, SC_STATUS_ADMIN_REVOKED))
+						dp = NULL;
+					spin_unlock(&state_lock);
+					if (dp)
+						revoke_delegation(dp);
+					break;
 				}
 				nfs4_put_stid(stid);
 				spin_lock(&nn->client_lock);
@@ -4676,6 +4691,7 @@ static void nfsd4_drop_revoked_stid(struct nfs4_stid *s)
 	struct nfs4_client *cl = s->sc_client;
 	LIST_HEAD(reaplist);
 	struct nfs4_ol_stateid *stp;
+	struct nfs4_delegation *dp;
 	bool unhashed;
 
 	switch (s->sc_type) {
@@ -4693,6 +4709,12 @@ static void nfsd4_drop_revoked_stid(struct nfs4_stid *s)
 		if (unhashed)
 			nfs4_put_stid(s);
 		break;
+	case SC_TYPE_DELEG:
+		dp = delegstateid(s);
+		list_del_init(&dp->dl_recall_lru);
+		spin_unlock(&cl->cl_lock);
+		nfs4_put_stid(s);
+		break;
 	default:
 		spin_unlock(&cl->cl_lock);
 	}