From: Jiufei Xue <jiufei.xue@linux.alibaba.com> mainline inclusion from mainline-5.9-rc1 commit a31eb4a2f1650fa578082ad9e9845487ecd90abe category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA --------------------------- Applications can pass this flag in to avoid accept thundering herd. Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: yangerkun <yangerkun@huawei.com> Reviewed-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Cheng Jian <cj.chengjian@huawei.com> --- fs/io_uring.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 78f67c41efd5..f7ffea95c907 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4210,7 +4210,11 @@ static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt, pt->error = 0; poll->head = head; - add_wait_queue(head, &poll->wait); + + if (poll->events & EPOLLEXCLUSIVE) + add_wait_queue_exclusive(head, &poll->wait); + else + add_wait_queue(head, &poll->wait); } static void io_async_queue_proc(struct file *file, struct wait_queue_head *head, @@ -4567,7 +4571,8 @@ static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe #ifdef __BIG_ENDIAN events = swahw32(events); #endif - poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP; + poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP | + (events & EPOLLEXCLUSIVE); io_get_req_task(req); return 0; -- 2.25.1