This is a note to let you know that I've just added the patch titled
io_uring: add completion locking for iopoll
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
io_uring-add-completion-locking-for-iopoll.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2ccc92f4effcfa1c51c4fcf1e34d769099d3cad4 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
Date: Wed, 23 Nov 2022 11:33:36 +0000
Subject: io_uring: add completion locking for iopoll
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
commit 2ccc92f4effcfa1c51c4fcf1e34d769099d3cad4 upstream.
There are pieces of code that may allow iopoll to race filling cqes,
temporarily add spinlocking around posting events.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/84d86b5c117feda075471c5c9e65208e0dccf5d0.1669203009.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/rw.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -1043,6 +1043,7 @@ int io_do_iopoll(struct io_ring_ctx *ctx
else if (!pos)
return 0;
+ spin_lock(&ctx->completion_lock);
prev = start;
wq_list_for_each_resume(pos, prev) {
struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list);
@@ -1057,11 +1058,11 @@ int io_do_iopoll(struct io_ring_ctx *ctx
req->cqe.flags = io_put_kbuf(req, 0);
__io_fill_cqe_req(req->ctx, req);
}
-
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
if (unlikely(!nr_events))
return 0;
- io_commit_cqring(ctx);
io_cqring_ev_posted_iopoll(ctx);
pos = start ? start->next : ctx->iopoll_list.first;
wq_list_cut(&ctx->iopoll_list, prev, start);
Patches currently in stable-queue which might be from asml.silence@xxxxxxxxx are
queue-6.1/io_uring-net-introduce-ioring_send_zc_report_usage-flag.patch
queue-6.1/io_uring-net-fix-cleanup-after-recycle.patch
queue-6.1/io_uring-dont-remove-file-from-msg_ring-reqs.patch
queue-6.1/io_uring-protect-cq_timeouts-with-timeout_lock.patch
queue-6.1/io_uring-add-completion-locking-for-iopoll.patch
queue-6.1/io_uring-improve-io_double_lock_ctx-fail-handling.patch
