Commit 9466f437 authored Jan 25, 2020 by Pavel Begunkov Committed by Jens Axboe Jan 27, 2020

io_uring: fix refcounting with batched allocations at OOM



In case of out of memory the second argument of percpu_ref_put_many() in
io_submit_sqes() may evaluate into "nr - (-EAGAIN)", that is clearly
wrong.

Fixes: 2b85edfc ("io_uring: batch getting pcpu references")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 8cdf2193

fs/io_uring.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -4830,8 +4830,11 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
		break;
		}

		if (submitted != nr)
		percpu_ref_put_many(&ctx->refs, nr - submitted);
		if (unlikely(submitted != nr)) {
		int ref_used = (submitted == -EAGAIN) ? 0 : submitted;

		percpu_ref_put_many(&ctx->refs, nr - ref_used);
		}
		if (link)
		io_queue_link_head(link);
		if (statep)

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