io_uring: allow submissions to continue on error
By default, io_uring will stop submitting a batch of requests if we run
into an error submitting a request. This isn't strictly necessary, as
the error result is passed out-of-band via a CQE anyway. And it can be
a bit confusing for some applications.
Provide a way to setup a ring that will continue submitting on error,
when the error CQE has been posted.
There's still one case that will break out of submission. If we fail
allocating a request, then we'll still return -ENOMEM. We could in theory
post a CQE for that condition too even if we never got a request. Leave
that for a potential followup.
Reported-by: Dylan Yudaken <dylany@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 3145c9c..229b31d 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7801,8 +7801,14 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
}
/* will complete beyond this point, count as submitted */
submitted++;
- if (io_submit_sqe(ctx, req, sqe))
- break;
+ if (io_submit_sqe(ctx, req, sqe)) {
+ /*
+ * Continue submitting even for sqe failure if the
+ * ring was setup with IORING_SETUP_SUBMIT_ALL
+ */
+ if (!(ctx->flags & IORING_SETUP_SUBMIT_ALL))
+ break;
+ }
} while (submitted < nr);
if (unlikely(submitted != nr)) {
@@ -11265,7 +11271,7 @@ static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |
- IORING_SETUP_R_DISABLED))
+ IORING_SETUP_R_DISABLED | IORING_SETUP_SUBMIT_ALL))
return -EINVAL;
return io_uring_create(entries, &p, params);
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 8bd4bfd..d2be4eb 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -101,6 +101,7 @@ enum {
#define IORING_SETUP_CLAMP (1U << 4) /* clamp SQ/CQ ring sizes */
#define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */
#define IORING_SETUP_R_DISABLED (1U << 6) /* start with ring disabled */
+#define IORING_SETUP_SUBMIT_ALL (1U << 7) /* continue submit on error */
enum {
IORING_OP_NOP,
