From d9aacf7e1ec71611f17739e73c5448457cc23efd Mon Sep 17 00:00:00 2001 From: yangerkun Date: Tue, 24 Sep 2019 20:53:34 +0800 Subject: [PATCH 0654/2944] io_uring: compare cached_cq_tail with cq.head in_io_uring_poll commit daa5de5415849b9a53056ec1e1e88fe4c5c9aa2b upstream. After 75b28af("io_uring: allocate the two rings together"), we compare sq.head with cached_cq_tail to determine does there any cq invalid. Actually, we should use cq.head. Fixes: 75b28affdd6a ("io_uring: allocate the two rings together") Signed-off-by: yangerkun Signed-off-by: Jens Axboe Signed-off-by: Joseph Qi Reviewed-by: Xiaoguang Wang --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 908d22b..9bece4c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3455,7 +3455,7 @@ static __poll_t io_uring_poll(struct file *file, poll_table *wait) if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head != ctx->rings->sq_ring_entries) mask |= EPOLLOUT | EPOLLWRNORM; - if (READ_ONCE(ctx->rings->sq.head) != ctx->cached_cq_tail) + if (READ_ONCE(ctx->rings->cq.head) != ctx->cached_cq_tail) mask |= EPOLLIN | EPOLLRDNORM; return mask; -- 1.8.3.1