Commit 5e559561 authored Nov 13, 2019 by Jens Axboe

io_uring: ensure registered buffer import returns the IO length



A test case was reported where two linked reads with registered buffers
failed the second link always. This is because we set the expected value
of a request in req->result, and if we don't get this result, then we
fail the dependent links. For some reason the registered buffer import
returned -ERROR/0, while the normal import returns -ERROR/length. This
broke linked commands with registered buffers.

Fix this by making io_import_fixed() correctly return the mapped length.

Cc: stable@vger.kernel.org # v5.3
Reported-by: 李通洲 <carter.li@eoitek.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 5683e540

fs/io_uring.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1230,7 +1230,7 @@ static int io_import_fixed(struct io_ring_ctx *ctx, int rw,
		}
		}

		return 0;
		return len;
		}

		static ssize_t io_import_iovec(struct io_ring_ctx *ctx, int rw,

Admin message