From e0deb6a025ae8c850dc8685be39fb27b06c88736 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Fri, 13 May 2022 11:24:56 +0100
Subject: [PATCH] io_uring: avoid io-wq -EAGAIN looping for !IOPOLL
Git-commit: e0deb6a025ae8c850dc8685be39fb27b06c88736
Patch-mainline: v5.19-rc1
References: bsc#1205205

If an opcode handler semi-reliably returns -EAGAIN, io_wq_submit_work()
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 where there is no other
recourse than to retry as we cannot wait.

Fixes: def596e9557c9 ("io_uring: support for IO polling")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f168b4f24181942f3614dd8ff648221736f572e6.1652433740.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
 fs/io_uring.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 362189819898..f5f38329c823 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7573,6 +7573,8 @@ 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;
 		}
-- 
2.35.3