From 1c8b49851543f41fc8bb18bcd1f15cc93d14b530 Mon Sep 17 00:00:00 2001 From: Cheng Yongkang Date: Thu, 29 Oct 2026 07:12:20 -0700 Subject: [PATCH] io_uring/timeout: count cancelled timeouts in cq_timeouts io_timeout_cancel() posts the cancelled timeout's -ECANCELED CQE without advancing ctx->cq_timeouts. io_timeout_fn() and io_kill_timeout() advance it for every timeout CQE they post, and io_flush_timeouts() computes the number of non-timeout completions as seq = cached_cq_tail - cq_timeouts to compare against each off timeout's target_seq. The cancelled timeout's CQE is therefore counted as a regular completion, so every cancellation makes an already armed off timeout fire one completion early. A ring with a keep-alive timeout of off=4 completes it after two NOPs when one off=100 victim is cancelled through IORING_OP_ASYNC_CANCEL, and before any NOP when two victims are cancelled. The cancel CQE should count, but the cancelled timeouts' -ECANCELED CQEs must not: the expected counts are three and two NOPs respectively. Advance cq_timeouts when io_timeout_extract() succeeds, under timeout_lock and before the -ECANCELED completion is queued, matching io_timeout_fn() and io_kill_timeout(). The -ENOENT and -EALREADY paths post no new timeout CQE and keep their accounting. Both the ASYNC_CANCEL and the TIMEOUT_REMOVE path go through io_timeout_cancel(). Fixes: bfe68a221905 ("io_uring: off timeouts based only on completions") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Cheng Yongkang Link: https://patch.msgid.link/179328314078.648427.13761781546953594668@gmail.com Signed-off-by: Jens Axboe --- io_uring/timeout.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/io_uring/timeout.c b/io_uring/timeout.c index 8a2108aa14ae..fa7b0d9a81d6 100644 --- a/io_uring/timeout.c +++ b/io_uring/timeout.c @@ -370,6 +370,9 @@ int io_timeout_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd) raw_spin_lock_irq(&ctx->timeout_lock); req = io_timeout_extract(ctx, cd); + if (!IS_ERR(req)) + atomic_set(&ctx->cq_timeouts, + atomic_read(&ctx->cq_timeouts) + 1); raw_spin_unlock_irq(&ctx->timeout_lock); if (IS_ERR(req))