From: Jens Axboe <axboe@kernel.dk> mainline inclusion from mainline-5.4-rc1 commit b2a9eadab85730935f5a6fe19f3f61faaaced601 category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA --------------------------- The way the logic is setup in io_uring_enter() means that you can't wake up the SQ poller thread while at the same time waiting (or polling) for completions afterwards. There's no reason for that to be the case. Reported-by: Lewis Baker <lbaker@fb.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> 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 | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 4af831003956..f9d570bda423 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3356,15 +3356,12 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, * Just return the requested submit count, and wake the thread if * we were asked to. */ + ret = 0; if (ctx->flags & IORING_SETUP_SQPOLL) { if (flags & IORING_ENTER_SQ_WAKEUP) wake_up(&ctx->sqo_wait); submitted = to_submit; - goto out_ctx; - } - - ret = 0; - if (to_submit) { + } else if (to_submit) { bool block_for_last = false; to_submit = min(to_submit, ctx->sq_entries); @@ -3394,7 +3391,6 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, } } -out_ctx: io_ring_drop_ctx_refs(ctx, 1); out_fput: fdput(f); -- 2.25.1