io_uring: remove extra sqpoll submission halting
SQPOLL task won't submit requests for a context that is currently dying,
so no need to remove ctx from sqd_list prior the main loop of
io_ring_exit_work(). Kill it, will be removed by io_sq_thread_finish()
and only brings confusion and lockups.
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f220c2b786ba0f9499bebc9f3cd9714d29efb6a5.1618752958.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index e491b81..4fc54cd 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6750,6 +6750,10 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
if (!list_empty(&ctx->iopoll_list))
io_do_iopoll(ctx, &nr_events, 0);
+ /*
+ * Don't submit if refs are dying, good for io_uring_register(),
+ * but also it is relied upon by io_ring_exit_work()
+ */
if (to_submit && likely(!percpu_ref_is_dying(&ctx->refs)) &&
!(ctx->flags & IORING_SETUP_R_DISABLED))
ret = io_submit_sqes(ctx, to_submit);
@@ -8540,14 +8544,6 @@ static void io_ring_exit_work(struct work_struct *work)
struct io_tctx_node *node;
int ret;
- /* prevent SQPOLL from submitting new requests */
- if (ctx->sq_data) {
- io_sq_thread_park(ctx->sq_data);
- list_del_init(&ctx->sqd_list);
- io_sqd_update_thread_idle(ctx->sq_data);
- io_sq_thread_unpark(ctx->sq_data);
- }
-
/*
* If we're doing polled IO and end up having requests being
* submitted async (out-of-line), then completions can come in while