diff mbox series

Stable inclusion request

Message ID e708995f-6666-fbdd-9373-792007e7ea73@kernel.dk
State New
Headers show
Series Stable inclusion request | expand

Commit Message

Jens Axboe Aug. 11, 2020, 1:14 a.m. UTC 
Hi,

Can we queue up a backport of:

commit 4c6e277c4cc4a6b3b2b9c66a7b014787ae757cc1                                 
Author: Jens Axboe <axboe@kernel.dk>                                            
Date:   Wed Jul 1 11:29:10 2020 -0600                                           
                                                                                
    io_uring: abstract out task work running

for 5.7 and 5.8 stable? It fixes a reported issue from Dave Chinner,
since the abstraction also ensures that we always set the current
task state appropriately before running task work.

I've attached both a 5.8 and 5.7 port of the patch.

Thanks!
diff mbox series

Patch

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 4e09af1d5d22..92bbbcff7777 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1692,6 +1692,17 @@  static int io_put_kbuf(struct io_kiocb *req)
 	return cflags;
 }
 
+static inline bool io_run_task_work(void)
+{
+	if (current->task_works) {
+		__set_current_state(TASK_RUNNING);
+		task_work_run();
+		return true;
+	}
+
+	return false;
+}
+
 static void io_iopoll_queue(struct list_head *again)
 {
 	struct io_kiocb *req;
@@ -1881,6 +1892,7 @@  static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
 		 */
 		if (!(++iters & 7)) {
 			mutex_unlock(&ctx->uring_lock);
+			io_run_task_work();
 			mutex_lock(&ctx->uring_lock);
 		}
 
@@ -4421,7 +4433,6 @@  static void io_async_task_func(struct callback_head *cb)
 		return;
 	}
 
-	__set_current_state(TASK_RUNNING);
 	if (io_sq_thread_acquire_mm(ctx, req)) {
 		io_cqring_add_event(req, -EFAULT);
 		goto end_req;
@@ -6153,8 +6164,7 @@  static int io_sq_thread(void *data)
 			if (!list_empty(&ctx->poll_list) || need_resched() ||
 			    (!time_after(jiffies, timeout) && ret != -EBUSY &&
 			    !percpu_ref_is_dying(&ctx->refs))) {
-				if (current->task_works)
-					task_work_run();
+				io_run_task_work();
 				cond_resched();
 				continue;
 			}
@@ -6186,8 +6196,7 @@  static int io_sq_thread(void *data)
 					finish_wait(&ctx->sqo_wait, &wait);
 					break;
 				}
-				if (current->task_works) {
-					task_work_run();
+				if (io_run_task_work()) {
 					finish_wait(&ctx->sqo_wait, &wait);
 					continue;
 				}
@@ -6211,8 +6220,7 @@  static int io_sq_thread(void *data)
 		timeout = jiffies + ctx->sq_thread_idle;
 	}
 
-	if (current->task_works)
-		task_work_run();
+	io_run_task_work();
 
 	set_fs(old_fs);
 	io_sq_thread_drop_mm(ctx);
@@ -6278,9 +6286,8 @@  static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
 	do {
 		if (io_cqring_events(ctx, false) >= min_events)
 			return 0;
-		if (!current->task_works)
+		if (!io_run_task_work())
 			break;
-		task_work_run();
 	} while (1);
 
 	if (sig) {
@@ -6302,8 +6309,8 @@  static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
 		prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
 						TASK_INTERRUPTIBLE);
 		/* make sure we run task_work before checking for signals */
-		if (current->task_works)
-			task_work_run();
+		if (io_run_task_work())
+			continue;
 		if (signal_pending(current)) {
 			if (current->jobctl & JOBCTL_TASK_WORK) {
 				spin_lock_irq(&current->sighand->siglock);
@@ -7691,8 +7698,7 @@  SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
 	int submitted = 0;
 	struct fd f;
 
-	if (current->task_works)
-		task_work_run();
+	io_run_task_work();
 
 	if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP))
 		return -EINVAL;