[PATCH 6/6] nfsd: allow delegation state ids to be revoked and then freed

[NeilBrown <neilb@xxxxxxx>]

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.

Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
 fs/nfsd/nfs4state.c | 36 +++++++++++++++++++++++++++++-------
 1 file changed, 29 insertions(+), 7 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index ed879f68944b..9fdbdc64262d 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1367,7 +1367,8 @@ static void destroy_delegation(struct nfs4_delegation *dp)
 		destroy_unhashed_deleg(dp);
 }
 
-static void revoke_delegation(struct nfs4_delegation *dp)
+static void revoke_delegation(struct nfs4_delegation *dp,
+			      unsigned short sc_type)
 {
 	struct nfs4_client *clp = dp->dl_stid.sc_client;
 
@@ -1375,9 +1376,9 @@ static void revoke_delegation(struct nfs4_delegation *dp)
 
 	trace_nfsd_stid_revoke(&dp->dl_stid);
 
-	if (clp->cl_minorversion) {
+	if (clp->cl_minorversion || sc_type == NFS4_ADMIN_REVOKED_DELEG_STID) {
 		spin_lock(&clp->cl_lock);
-		dp->dl_stid.sc_type = NFS4_REVOKED_DELEG_STID;
+		dp->dl_stid.sc_type = sc_type;
 		refcount_inc(&dp->dl_stid.sc_count);
 		list_add(&dp->dl_recall_lru, &clp->cl_revoked);
 		spin_unlock(&clp->cl_lock);
@@ -1708,7 +1709,7 @@ void nfsd4_revoke_states(struct net *net, struct super_block *sb)
 	unsigned int idhashval;
 	unsigned short sc_types;
 
-	sc_types = NFS4_OPEN_STID | NFS4_LOCK_STID;
+	sc_types = NFS4_OPEN_STID | NFS4_LOCK_STID | NFS4_DELEG_STID;
 
 	spin_lock(&nn->client_lock);
 	for (idhashval = 0; idhashval < CLIENT_HASH_MASK; idhashval++) {
@@ -1720,6 +1721,7 @@ 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) {
@@ -1758,6 +1760,18 @@ void nfsd4_revoke_states(struct net *net, struct super_block *sb)
 					}
 					mutex_unlock(&stp->st_mutex);
 					break;
+				case NFS4_DELEG_STID:
+					dp = delegstateid(stid);
+					spin_lock(&state_lock);
+					if (!unhash_delegation_locked(dp))
+						dp = NULL;
+					spin_unlock(&state_lock);
+					if (dp) {
+						list_del_init(&dp->dl_recall_lru);
+						revoke_delegation(
+							dp, NFS4_ADMIN_REVOKED_DELEG_STID);
+					}
+					break;
 				}
 				nfs4_put_stid(stid);
 				spin_lock(&nn->client_lock);
@@ -4695,6 +4709,7 @@ static void nfsd_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) {
@@ -4712,6 +4727,12 @@ static void nfsd_drop_revoked_stid(struct nfs4_stid *s)
 		if (unhashed)
 			nfs4_put_stid(s);
 		break;
+	case NFS4_ADMIN_REVOKED_DELEG_STID:
+		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);
 	}
@@ -5073,8 +5094,9 @@ static int nfsd4_cb_recall_done(struct nfsd4_callback *cb,
 	trace_nfsd_cb_recall_done(&dp->dl_stid.sc_stateid, task);
 
 	if (dp->dl_stid.sc_type == NFS4_CLOSED_DELEG_STID ||
-	    dp->dl_stid.sc_type == NFS4_REVOKED_DELEG_STID)
-	        return 1;
+	    dp->dl_stid.sc_type == NFS4_REVOKED_DELEG_STID ||
+	    dp->dl_stid.sc_type == NFS4_ADMIN_REVOKED_DELEG_STID)
+		return 1;
 
 	switch (task->tk_status) {
 	case 0:
@@ -6438,7 +6460,7 @@ nfs4_laundromat(struct nfsd_net *nn)
 		dp = list_first_entry(&reaplist, struct nfs4_delegation,
 					dl_recall_lru);
 		list_del_init(&dp->dl_recall_lru);
-		revoke_delegation(dp);
+		revoke_delegation(dp, NFS4_REVOKED_DELEG_STID);
 	}
 
 	spin_lock(&nn->client_lock);
-- 
2.42.0