From edd43f4d6f50ec3de55a0c9e9df6348d1da51965 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 24 Apr 2025 10:28:14 -0600 Subject: [PATCH] io_uring: fix 'sync' handling of io_fallback_tw() A previous commit added a 'sync' parameter to io_fallback_tw(), which if true, means the caller wants to wait on the fallback thread handling it. But the logic is somewhat messed up, ensure that ctxs are swapped and flushed appropriately. Cc: stable@vger.kernel.org Fixes: dfbe5561ae93 ("io_uring: flush offloaded and delayed task_work on exit") Signed-off-by: Jens Axboe --- io_uring/io_uring.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index eedb47c8c79e..a2b256e96d5d 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1083,21 +1083,22 @@ static __cold void __io_fallback_tw(struct llist_node *node, bool sync) while (node) { req = container_of(node, struct io_kiocb, io_task_work.node); node = node->next; - if (sync && last_ctx != req->ctx) { + if (last_ctx != req->ctx) { if (last_ctx) { - flush_delayed_work(&last_ctx->fallback_work); + if (sync) + flush_delayed_work(&last_ctx->fallback_work); percpu_ref_put(&last_ctx->refs); } last_ctx = req->ctx; percpu_ref_get(&last_ctx->refs); } - if (llist_add(&req->io_task_work.node, - &req->ctx->fallback_llist)) - schedule_delayed_work(&req->ctx->fallback_work, 1); + if (llist_add(&req->io_task_work.node, &last_ctx->fallback_llist)) + schedule_delayed_work(&last_ctx->fallback_work, 1); } if (last_ctx) { - flush_delayed_work(&last_ctx->fallback_work); + if (sync) + flush_delayed_work(&last_ctx->fallback_work); percpu_ref_put(&last_ctx->refs); } } -- 2.25.1