This is a note to let you know that I've just added the patch titled io_uring: refactor scheduling in io_cqring_wait to the 5.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-refactor-scheduling-in-io_cqring_wait.patch and it can be found in the queue-5.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 03fc298d186de3b2ce9936c6112c21f03ddd76f2 Author: Pavel Begunkov <asml.silence@xxxxxxxxx> Date: Thu Feb 4 13:51:57 2021 +0000 io_uring: refactor scheduling in io_cqring_wait [ Upstream commit c1d5a224683b333ddbe278e455d639ccd4f5ca2b ] schedule_timeout() with timeout=MAX_SCHEDULE_TIMEOUT is guaranteed to work just as schedule(), so instead of hand-coding it based on arguments always use the timeout version and simplify code. Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/io_uring.c b/fs/io_uring.c index 68508f010b90..3e610ac062a3 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7226,9 +7226,8 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, .to_wait = min_events, }; struct io_rings *rings = ctx->rings; - struct timespec64 ts; - signed long timeout = 0; - int ret = 0; + signed long timeout = MAX_SCHEDULE_TIMEOUT; + int ret; do { io_cqring_overflow_flush(ctx, false, NULL, NULL); @@ -7252,6 +7251,8 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, } if (uts) { + struct timespec64 ts; + if (get_timespec64(&ts, uts)) return -EFAULT; timeout = timespec64_to_jiffies(&ts); @@ -7277,14 +7278,10 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, finish_wait(&ctx->wait, &iowq.wq); continue; } - if (uts) { - timeout = schedule_timeout(timeout); - if (timeout == 0) { - ret = -ETIME; - break; - } - } else { - schedule(); + timeout = schedule_timeout(timeout); + if (timeout == 0) { + ret = -ETIME; + break; } } while (1); finish_wait(&ctx->wait, &iowq.wq);