Merge tag 'nfsd-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fixes from Chuck Lever:

 - Fix crashes triggered by administrative operations on the server

* tag 'nfsd-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  NFSD: grab nfsd_mutex in nfsd_nl_rpc_status_get_dumpit()
  nfsd: fix oops when reading pool_stats before server is started

Documentation/netlink/specs/nfsd.yaml

@@ -123,8 +123,6 @@ operations:
       doc: dump pending nfsd rpc
       attribute-set: rpc-status
       dump:
-        pre: nfsd-nl-rpc-status-get-start
-        post: nfsd-nl-rpc-status-get-done
         reply:
           attributes:
             - xid

fs/nfsd/netlink.c

@@ -44,9 +44,7 @@ static const struct nla_policy nfsd_listener_set_nl_policy[NFSD_A_SERVER_SOCK_AD
 static const struct genl_split_ops nfsd_nl_ops[] = {
 	{
 		.cmd	= NFSD_CMD_RPC_STATUS_GET,
-		.start	= nfsd_nl_rpc_status_get_start,
 		.dumpit	= nfsd_nl_rpc_status_get_dumpit,
-		.done	= nfsd_nl_rpc_status_get_done,
 		.flags	= GENL_CMD_CAP_DUMP,
 	},
 	{

fs/nfsd/netlink.h

@@ -15,9 +15,6 @@
 extern const struct nla_policy nfsd_sock_nl_policy[NFSD_A_SOCK_TRANSPORT_NAME + 1];
 extern const struct nla_policy nfsd_version_nl_policy[NFSD_A_VERSION_ENABLED + 1];
 
-int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb);
-int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb);
-
 int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
 				  struct netlink_callback *cb);
 int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *info);

fs/nfsd/nfsctl.c

@@ -1460,28 +1460,6 @@ static int create_proc_exports_entry(void)
 
 unsigned int nfsd_net_id;
 
-/**
- * nfsd_nl_rpc_status_get_start - Prepare rpc_status_get dumpit
- * @cb: netlink metadata and command arguments
- *
- * Return values:
- *   %0: The rpc_status_get command may proceed
- *   %-ENODEV: There is no NFSD running in this namespace
- */
-int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb)
-{
-	struct nfsd_net *nn = net_generic(sock_net(cb->skb->sk), nfsd_net_id);
-	int ret = -ENODEV;
-
-	mutex_lock(&nfsd_mutex);
-	if (nn->nfsd_serv)
-		ret = 0;
-	else
-		mutex_unlock(&nfsd_mutex);
-
-	return ret;
-}
-
 static int nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb,
 					    struct netlink_callback *cb,
 					    struct nfsd_genl_rqstp *rqstp)
@@ -1558,8 +1536,16 @@ static int nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb,
 int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
 				  struct netlink_callback *cb)
 {
-	struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id);
 	int i, ret, rqstp_index = 0;
+	struct nfsd_net *nn;
+
+	mutex_lock(&nfsd_mutex);
+
+	nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+	if (!nn->nfsd_serv) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
 
 	rcu_read_lock();
 
@@ -1636,22 +1622,10 @@ int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
 	ret = skb->len;
 out:
 	rcu_read_unlock();
-
-	return ret;
-}
-
-/**
- * nfsd_nl_rpc_status_get_done - rpc_status_get dumpit post-processing
- * @cb: netlink metadata and command arguments
- *
- * Return values:
- *   %0: Success
- */
-int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb)
-{
+out_unlock:
 	mutex_unlock(&nfsd_mutex);
 
-	return 0;
+	return ret;
 }
 
 /**

net/sunrpc/svc_xprt.c

@@ -1421,12 +1421,13 @@ static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
 
 	dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
 
+	if (!si->serv)
+		return NULL;
+
 	mutex_lock(si->mutex);
 
 	if (!pidx)
 		return SEQ_START_TOKEN;
-	if (!si->serv)
-		return NULL;
 	return pidx > si->serv->sv_nrpools ? NULL
 		: &si->serv->sv_pools[pidx - 1];
 }
@@ -1458,7 +1459,8 @@ static void svc_pool_stats_stop(struct seq_file *m, void *p)
 {
 	struct svc_info *si = m->private;
 
-	mutex_unlock(si->mutex);
+	if (si->serv)
+		mutex_unlock(si->mutex);
 }
 
 static int svc_pool_stats_show(struct seq_file *m, void *p)