From 7a8a6b627fded72e9e177730dc7e225d17c65c03 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() commit edd43f4d6f50ec3de55a0c9e9df6348d1da51965 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- 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 19de7129ae0b..9bbcd5742bc2 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1103,21 +1103,22 @@ static __cold void io_fallback_tw(struct io_uring_task *tctx, 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); } } -- 2.34.1