From 19352a1d395424b5f8c03289a85fbd6622d6601a Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Tue, 30 Apr 2024 16:42:31 +0100 Subject: [PATCH] io_uring/notif: disable LAZY_WAKE for linked notifs Notifications may now be linked and thus a single tw can post multiple CQEs, it's not safe to use LAZY_WAKE with them. Disable LAZY_WAKE for now, if that'd prove to be a problem we can count them and pass the expected number of CQEs into __io_req_task_work_add(). Fixes: 6fe4220912d19 ("io_uring/notif: implement notification stacking") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/0a5accdb7d2d0d27ebec14f8106e14e0192fae17.1714488419.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- io_uring/notif.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/io_uring/notif.c b/io_uring/notif.c index d58cdc01e691..28859ae3ee6e 100644 --- a/io_uring/notif.c +++ b/io_uring/notif.c @@ -38,6 +38,7 @@ void io_tx_ubuf_complete(struct sk_buff *skb, struct ubuf_info *uarg, { struct io_notif_data *nd = container_of(uarg, struct io_notif_data, uarg); struct io_kiocb *notif = cmd_to_io_kiocb(nd); + unsigned tw_flags; if (nd->zc_report) { if (success && !nd->zc_used && skb) @@ -53,8 +54,10 @@ void io_tx_ubuf_complete(struct sk_buff *skb, struct ubuf_info *uarg, io_tx_ubuf_complete(skb, &nd->head->uarg, success); return; } + + tw_flags = nd->next ? 0 : IOU_F_TWQ_LAZY_WAKE; notif->io_task_work.func = io_notif_tw_complete; - __io_req_task_work_add(notif, IOU_F_TWQ_LAZY_WAKE); + __io_req_task_work_add(notif, tw_flags); } static int io_link_skb(struct sk_buff *skb, struct ubuf_info *uarg)