From 4e88d6e7793f2f445f43bd608828541d7f43b608 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sat, 7 Dec 2019 20:59:47 -0700 Subject: io_uring: allow unbreakable links MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some commands will invariably end in a failure in the sense that the completion result will be less than zero. One such example is timeouts that don't have a completion count set, they will always complete with -ETIME unless cancelled. For linked commands, we sever links and fail the rest of the chain if the result is less than zero. Since we have commands where we know that will happen, add IOSQE_IO_HARDLINK as a stronger link that doesn't sever regardless of the completion result. Note that the link will still sever if we fail submitting the parent request, hard links are only resilient in the presence of completion results for requests that did submit correctly. Cc: stable@vger.kernel.org # v5.4 Reviewed-by: Pavel Begunkov Reported-by: 李通洲 Signed-off-by: Jens Axboe --- include/uapi/linux/io_uring.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index eabccb46edd1..ea231366f5fd 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -48,6 +48,7 @@ struct io_uring_sqe { #define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */ #define IOSQE_IO_DRAIN (1U << 1) /* issue after inflight IO */ #define IOSQE_IO_LINK (1U << 2) /* links next sqe */ +#define IOSQE_IO_HARDLINK (1U << 3) /* like LINK, but stronger */ /* * io_uring_setup() flags -- cgit v1.2.3-59-g8ed1b