From f6d54255f4235448d4bbe442362d4caa62da97d5 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Sun, 14 Mar 2021 20:57:11 +0000 Subject: [PATCH] io_uring: halt SQO submission on ctx exit io_sq_thread_finish() is called in io_ring_ctx_free(), so SQPOLL task is potentially running submitting new requests. It's not a disaster because of using a "try" variant of percpu_ref_get, but is far from nice. Remove ctx from the sqd ctx list earlier, before cancellation loop, so SQPOLL can't find it and so won't submit new requests. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 6de779aafd33..b87012a21775 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8564,6 +8564,14 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) io_unregister_personality(ctx, index); mutex_unlock(&ctx->uring_lock); + /* 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); + } + io_kill_timeouts(ctx, NULL, NULL); io_poll_remove_all(ctx, NULL, NULL);