From: Pavel Begunkov Date: Tue, 17 Aug 2021 21:36:44 +0000 (+0100) Subject: io_uring: pin ctx on fallback execution X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=9cb0073b302a6b8a8c1015ff31b2b3ab4900f866;p=kernel.git io_uring: pin ctx on fallback execution Pin ring in io_fallback_req_func() by briefly elevating ctx->refs in case any task_work handler touches ctx after releasing a request. Fixes: 9011bf9a13e3b ("io_uring: fix stuck fallback reqs") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/833a494713d235ec144284a9bbfe418df4f6b61c.1629235576.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- diff --git a/fs/io_uring.c b/fs/io_uring.c index 6a092a534d2b5..979941bcd15a7 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2477,8 +2477,10 @@ static void io_fallback_req_func(struct work_struct *work) struct llist_node *node = llist_del_all(&ctx->fallback_llist); struct io_kiocb *req, *tmp; + percpu_ref_get(&ctx->refs); llist_for_each_entry_safe(req, tmp, node, io_task_work.fallback_node) req->io_task_work.func(req); + percpu_ref_put(&ctx->refs); } static void __io_complete_rw(struct io_kiocb *req, long res, long res2,