nfsd: call nfs4_put_deleg_lease outside of state_lock

Currently, we hold the state_lock when releasing the lease. That's
potentially problematic in the future if we allow for setlease methods
that can sleep. Move the nfs4_put_deleg_lease call out of the delegation
unhashing routine (which was always a bit goofy anyway), and into the
unlocked sections of the callers of unhash_delegation_locked.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4state.c

@@ -722,7 +722,6 @@ unhash_delegation_locked(struct nfs4_delegation *dp)
 	list_del_init(&dp->dl_recall_lru);
 	list_del_init(&dp->dl_perfile);
 	spin_unlock(&fp->fi_lock);
-	nfs4_put_deleg_lease(fp);
 }
 
 static void destroy_delegation(struct nfs4_delegation *dp)
@@ -730,6 +729,7 @@ static void destroy_delegation(struct nfs4_delegation *dp)
 	spin_lock(&state_lock);
 	unhash_delegation_locked(dp);
 	spin_unlock(&state_lock);
+	nfs4_put_deleg_lease(dp->dl_stid.sc_file);
 	nfs4_put_stid(&dp->dl_stid);
 }
 
@@ -739,6 +739,8 @@ static void revoke_delegation(struct nfs4_delegation *dp)
 
 	WARN_ON(!list_empty(&dp->dl_recall_lru));
 
+	nfs4_put_deleg_lease(dp->dl_stid.sc_file);
+
 	if (clp->cl_minorversion == 0)
 		nfs4_put_stid(&dp->dl_stid);
 	else {
@@ -1639,6 +1641,7 @@ __destroy_client(struct nfs4_client *clp)
 	while (!list_empty(&reaplist)) {
 		dp = list_entry(reaplist.next, struct nfs4_delegation, dl_recall_lru);
 		list_del_init(&dp->dl_recall_lru);
+		nfs4_put_deleg_lease(dp->dl_stid.sc_file);
 		nfs4_put_stid(&dp->dl_stid);
 	}
 	while (!list_empty(&clp->cl_revoked)) {
@@ -6406,6 +6409,7 @@ nfs4_state_shutdown_net(struct net *net)
 	list_for_each_safe(pos, next, &reaplist) {
 		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
 		list_del_init(&dp->dl_recall_lru);
+		nfs4_put_deleg_lease(dp->dl_stid.sc_file);
 		nfs4_put_stid(&dp->dl_stid);
 	}