Merge tag 'dlm-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm

Pull dlm updates from David Teigland:
 "There are four fixes/cleanups in this series; none are likely to be
  issues in real usage:

   - improve debugfs error exit path

   - fix sequence number ordering in an artificial test case

   - fix usercopy_abort for lvb data

   - use hlist_for_each_entry_srcu for srcu lists"

* tag 'dlm-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm:
  dlm: init per node debugfs before add to node hash
  dlm: fix add msg handle in send_queue ordered
  dlm: add usercopy whitelist to dlm_cb cache
  dlm: use hlist_for_each_entry_srcu for SRCU protected lists

Author: torvalds

fs/dlm/lowcomms.c

@@ -271,7 +271,8 @@ static struct connection *__find_con(int nodeid, int r)
 {
 	struct connection *con;
 
-	hlist_for_each_entry_rcu(con, &connection_hash[r], list) {
+	hlist_for_each_entry_srcu(con, &connection_hash[r], list,
+			srcu_read_lock_held(&connections_srcu)) {
 		if (con->nodeid == nodeid)
 			return con;
 	}
@@ -426,7 +427,8 @@ static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid,
 
 	idx = srcu_read_lock(&connections_srcu);
 	for (i = 0; i < CONN_HASH_SIZE; i++) {
-		hlist_for_each_entry_rcu(con, &connection_hash[i], list) {
+		hlist_for_each_entry_srcu(con, &connection_hash[i], list,
+				srcu_read_lock_held(&connections_srcu)) {
 			WARN_ON_ONCE(!con->addr_count);
 
 			spin_lock(&con->addrs_lock);
@@ -1729,7 +1731,8 @@ void dlm_lowcomms_shutdown(void)
 
 	idx = srcu_read_lock(&connections_srcu);
 	for (i = 0; i < CONN_HASH_SIZE; i++) {
-		hlist_for_each_entry_rcu(con, &connection_hash[i], list) {
+		hlist_for_each_entry_srcu(con, &connection_hash[i], list,
+				srcu_read_lock_held(&connections_srcu)) {
 			shutdown_connection(con, true);
 			stop_connection_io(con);
 			flush_workqueue(process_workqueue);
@@ -1968,7 +1971,8 @@ void dlm_lowcomms_exit(void)
 
 	idx = srcu_read_lock(&connections_srcu);
 	for (i = 0; i < CONN_HASH_SIZE; i++) {
-		hlist_for_each_entry_rcu(con, &connection_hash[i], list) {
+		hlist_for_each_entry_srcu(con, &connection_hash[i], list,
+				srcu_read_lock_held(&connections_srcu)) {
 			spin_lock(&connections_lock);
 			hlist_del_rcu(&con->list);
 			spin_unlock(&connections_lock);

fs/dlm/memory.c

@@ -48,8 +48,10 @@ int __init dlm_memory_init(void)
 	if (!rsb_cache)
 		goto rsb;
 
-	cb_cache = kmem_cache_create("dlm_cb", sizeof(struct dlm_callback),
+	cb_cache = kmem_cache_create_usercopy("dlm_cb", sizeof(struct dlm_callback),
 				     __alignof__(struct dlm_callback), 0,
+					 offsetof(struct dlm_callback, lvbptr),
+					 sizeof_field(struct dlm_callback, lvbptr),
 				     NULL);
 	if (!cb_cache)
 		goto cb;

fs/dlm/midcomms.c

@@ -275,7 +275,8 @@ static struct midcomms_node *__find_node(int nodeid, int r)
 {
 	struct midcomms_node *node;
 
-	hlist_for_each_entry_rcu(node, &node_hash[r], hlist) {
+	hlist_for_each_entry_srcu(node, &node_hash[r], hlist,
+			srcu_read_lock_held(&nodes_srcu)) {
 		if (node->nodeid == nodeid)
 			return node;
 	}
@@ -355,6 +356,7 @@ int dlm_midcomms_addr(int nodeid, struct sockaddr_storage *addr)
 	if (!node)
 		return -ENOMEM;
 
+	node->debugfs = dlm_create_debug_comms_file(nodeid, node);
 	node->nodeid = nodeid;
 	spin_lock_init(&node->state_lock);
 	spin_lock_init(&node->send_queue_lock);
@@ -368,7 +370,6 @@ int dlm_midcomms_addr(int nodeid, struct sockaddr_storage *addr)
 	hlist_add_head_rcu(&node->hlist, &node_hash[r]);
 	spin_unlock_bh(&nodes_lock);
 
-	node->debugfs = dlm_create_debug_comms_file(nodeid, node);
 	return 0;
 }
 
@@ -968,10 +969,10 @@ static void midcomms_new_msg_cb(void *data)
 	atomic_inc(&mh->node->send_queue_cnt);
 
 	spin_lock_bh(&mh->node->send_queue_lock);
+	/* need to be locked with list_add_tail_rcu() because list is ordered */
+	mh->seq = atomic_fetch_inc(&mh->node->seq_send);
 	list_add_tail_rcu(&mh->list, &mh->node->send_queue);
 	spin_unlock_bh(&mh->node->send_queue_lock);
-
-	mh->seq = atomic_fetch_inc(&mh->node->seq_send);
 }
 
 static struct dlm_msg *dlm_midcomms_get_msg_3_2(struct dlm_mhandle *mh, int nodeid,
@@ -1165,7 +1166,8 @@ void dlm_midcomms_exit(void)
 
 	idx = srcu_read_lock(&nodes_srcu);
 	for (i = 0; i < CONN_HASH_SIZE; i++) {
-		hlist_for_each_entry_rcu(node, &node_hash[i], hlist) {
+		hlist_for_each_entry_srcu(node, &node_hash[i], hlist,
+				srcu_read_lock_held(&nodes_srcu)) {
 			dlm_delete_debug_comms_file(node->debugfs);
 
 			spin_lock(&nodes_lock);
@@ -1325,7 +1327,8 @@ void dlm_midcomms_version_wait(void)
 
 	idx = srcu_read_lock(&nodes_srcu);
 	for (i = 0; i < CONN_HASH_SIZE; i++) {
-		hlist_for_each_entry_rcu(node, &node_hash[i], hlist) {
+		hlist_for_each_entry_srcu(node, &node_hash[i], hlist,
+				srcu_read_lock_held(&nodes_srcu)) {
 			ret = wait_event_timeout(node->shutdown_wait,
 						 node->version != DLM_VERSION_NOT_SET ||
 						 node->state == DLM_CLOSED ||
@@ -1396,15 +1399,17 @@ void dlm_midcomms_shutdown(void)
 	mutex_lock(&close_lock);
 	idx = srcu_read_lock(&nodes_srcu);
 	for (i = 0; i < CONN_HASH_SIZE; i++) {
-		hlist_for_each_entry_rcu(node, &node_hash[i], hlist) {
+		hlist_for_each_entry_srcu(node, &node_hash[i], hlist,
+				srcu_read_lock_held(&nodes_srcu)) {
 			midcomms_shutdown(node);
 		}
 	}
 
 	dlm_lowcomms_shutdown();
 
 	for (i = 0; i < CONN_HASH_SIZE; i++) {
-		hlist_for_each_entry_rcu(node, &node_hash[i], hlist) {
+		hlist_for_each_entry_srcu(node, &node_hash[i], hlist,
+				srcu_read_lock_held(&nodes_srcu)) {
 			midcomms_node_reset(node);
 		}
 	}