[PATCH 6.1 1136/1146] io_uring: add completion locking for iopoll

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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);





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux