Commit daa5de54 authored Sep 24, 2019 by yangerkun Committed by Jens Axboe Sep 24, 2019

io_uring: compare cached_cq_tail with cq.head in_io_uring_poll



After 75b28aff("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: 75b28aff ("io_uring: allocate the two rings together")
Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 32960613

fs/io_uring.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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;

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