From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 30 Jan 2024 14:04:52 +0000 (-0700)
Subject: io_uring: handle traditional task_work in FIFO order
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=170539bdf1094e6e43e9aa86bf2dcaff0857df41;p=linux.git

io_uring: handle traditional task_work in FIFO order

For local task_work, which is used if IORING_SETUP_DEFER_TASKRUN is set,
we reverse the order of the lockless list before processing the work.
This is done to process items in the order in which they were queued, as
the llist always adds to the head.

Do the same for traditional task_work, so we have the same behavior for
both types.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index b1892cdd25c63..4678d9ec810be 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1266,7 +1266,7 @@ void tctx_task_work(struct callback_head *cb)
 
 	node = llist_del_all(&tctx->task_list);
 	if (node)
-		count = handle_tw_list(node, &ctx, &ts);
+		count = handle_tw_list(llist_reverse_order(node), &ctx, &ts);
 
 	ctx_flush_and_put(ctx, &ts);