From: NeilBrown <neilb@suse.de>
Date: Tue, 7 Dec 2021 11:15:41 +1100
Subject: [PATCH] nfsd: allow delegation state ids to be revoked and then freed
Patch-mainline: Submitted, Jan 2022 nfs-utils@vger.kernel.org
References: bsc#1192483

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@suse.de>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfsd/nfs4state.c |   35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)

--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1247,14 +1247,15 @@ static void destroy_delegation(struct nf
 		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;
 
 	WARN_ON(!list_empty(&dp->dl_recall_lru));
 
-	if (clp->cl_minorversion) {
-		dp->dl_stid.sc_type = NFS4_REVOKED_DELEG_STID;
+	if (clp->cl_minorversion || sc_type == NFS4_ADMIN_REVOKED_DELEG_STID) {
+		dp->dl_stid.sc_type = sc_type;
 		refcount_inc(&dp->dl_stid.sc_count);
 		spin_lock(&clp->cl_lock);
 		list_add(&dp->dl_recall_lru, &clp->cl_revoked);
@@ -1590,7 +1591,7 @@ void nfsd4_revoke_states(struct net *net
 	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++) {
@@ -1601,6 +1602,7 @@ void nfsd4_revoke_states(struct net *net
 			struct nfs4_stid *stid = find_sb_stid(clp, sb, sc_types);
 			if (stid) {
 				struct nfs4_ol_stateid *stp;
+				struct nfs4_delegation *dp;
 
 				spin_unlock(&nn->client_lock);
 				switch (stid->sc_type) {
@@ -1639,6 +1641,18 @@ void nfsd4_revoke_states(struct net *net
 					}
 					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);
@@ -4721,8 +4735,9 @@ static int nfsd4_cb_recall_done(struct n
 	struct nfs4_delegation *dp = cb_to_delegation(cb);
 
 	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:
@@ -5750,7 +5765,7 @@ 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);
@@ -5978,8 +5993,9 @@ nfsd4_lookup_stateid(struct nfsd4_compou
 	 */
 	if (typemask & NFS4_REVOKED_DELEG_STID)
 		return_revoked = true;
-	else if (typemask & NFS4_DELEG_STID)
-		typemask |= NFS4_REVOKED_DELEG_STID;
+	if (typemask & NFS4_DELEG_STID)
+		typemask |= NFS4_REVOKED_DELEG_STID |
+			NFS4_ADMIN_REVOKED_DELEG_STID;;
 
 	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid) ||
 		CLOSE_STATEID(stateid))
@@ -6320,6 +6336,7 @@ nfsd4_free_stateid(struct svc_rqst *rqst
 		ret = nfs_ok;
 		goto out;
 	case NFS4_REVOKED_DELEG_STID:
+	case NFS4_ADMIN_REVOKED_DELEG_STID:
 		spin_unlock(&s->sc_lock);
 		dp = delegstateid(s);
 		list_del_init(&dp->dl_recall_lru);