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Commit 9bf7933f authored by Roman Penyaev's avatar Roman Penyaev Committed by Jens Axboe
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io_uring: offload write to async worker in case of -EAGAIN 



In case of direct write -EAGAIN will be returned if page cache was
previously populated.  To avoid immediate completion of a request
with -EAGAIN error write has to be offloaded to the async worker,
like io_read() does.

Signed-off-by: default avatarRoman Penyaev <rpenyaev@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e6d1fa58

fs/io_uring.c

+15 −1
Original line number Diff line number Diff line
@@ -1022,6 +1022,8 @@ static int io_write(struct io_kiocb *req, const struct sqe_submit *s, 


	ret = rw_verify_area(WRITE, file, &kiocb->ki_pos, iov_count);

	if (!ret) {

		ssize_t ret2;



		/*

		 * Open-code file_start_write here to grab freeze protection,

		 * which will be released by another thread in
@@ -1036,7 +1038,19 @@ static int io_write(struct io_kiocb *req, const struct sqe_submit *s, 
						SB_FREEZE_WRITE);

		}

		kiocb->ki_flags |= IOCB_WRITE;

		io_rw_done(kiocb, call_write_iter(file, kiocb, &iter));



		ret2 = call_write_iter(file, kiocb, &iter);

		if (!force_nonblock || ret2 != -EAGAIN) {

			io_rw_done(kiocb, ret2);

		} else {

			/*

			 * If ->needs_lock is true, we're already in async

			 * context.

			 */

			if (!s->needs_lock)

				io_async_list_note(WRITE, req, iov_count);

			ret = -EAGAIN;

		}

	}

out_free:

	kfree(iovec);