On 5/15/22 08:31, Hao Xu wrote:
On 5/13/22 18:24, Pavel Begunkov wrote:
If an opcode handler semi-reliably returns -EAGAIN, io_wq_submit_work()
Hi Pavel,
When would it return -EAGAIN in non-IOPOLL mode?
I didn't see it in the wild but stumbled upon while preparing some
future patches. I hope it's not a real issue, but it's better to not
leave a way for some driver/etc. to abuse it.
might continue busily hammer the same handler over and over again, which
is not ideal. The -EAGAIN handling in question was put there only for
IOPOLL, so restrict it to IOPOLL mode only.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
fs/io_uring.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index e01f595f5b7d..3af1905efc78 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7319,6 +7319,8 @@ static void io_wq_submit_work(struct io_wq_work *work)
* wait for request slots on the block side.
*/
if (!needs_poll) {
+ if (!(req->ctx->flags & IORING_SETUP_IOPOLL))
+ break;
cond_resched();
continue;
}
--
Pavel Begunkov
