Commit e6d83d55 authored by Trond Myklebust's avatar Trond Myklebust Committed by Linus Torvalds
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[PATCH] SUNRPC: Fix potential deadlock in RPC code 



In rpc_wake_up() and rpc_wake_up_status(), it is possible for the call to
__rpc_wake_up_task() to fail if another thread happens to be calling
rpc_wake_up_task() on the same rpc_task.

Problem noticed by Bruno Faccini.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent c12e87f4

net/sunrpc/sched.c

+5 −8
Original line number Diff line number Diff line
@@ -515,16 +515,14 @@ struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue) 
 */

void rpc_wake_up(struct rpc_wait_queue *queue)

{

	struct rpc_task *task;



	struct rpc_task *task, *next;

	struct list_head *head;



	spin_lock_bh(&queue->lock);

	head = &queue->tasks[queue->maxpriority];

	for (;;) {

		while (!list_empty(head)) {

			task = list_entry(head->next, struct rpc_task, u.tk_wait.list);

		list_for_each_entry_safe(task, next, head, u.tk_wait.list)

			__rpc_wake_up_task(task);

		}

		if (head == &queue->tasks[0])

			break;

		head--;
@@ -541,14 +539,13 @@ void rpc_wake_up(struct rpc_wait_queue *queue) 
 */

void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)

{

	struct rpc_task *task, *next;

	struct list_head *head;

	struct rpc_task *task;



	spin_lock_bh(&queue->lock);

	head = &queue->tasks[queue->maxpriority];

	for (;;) {

		while (!list_empty(head)) {

			task = list_entry(head->next, struct rpc_task, u.tk_wait.list);

		list_for_each_entry_safe(task, next, head, u.tk_wait.list) {

			task->tk_status = status;

			__rpc_wake_up_task(task);

		}

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