From a48c0cbf28c03f6c590a14ceb31bf6e619c2f6da Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 9 Oct 2025 07:33:36 -0600 Subject: [PATCH] io_uring/waitid: have io_waitid_complete() remove wait queue entry Both callers of this need the entry potentially removed, so shift the removal into the completion side and kill it from the two callers. While at it, add a helper for removing the wait_queue_entry based on the passed in io_kiocb. Signed-off-by: Jens Axboe --- io_uring/waitid.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/io_uring/waitid.c b/io_uring/waitid.c index f25110fb1b12..ebe3769c54dc 100644 --- a/io_uring/waitid.c +++ b/io_uring/waitid.c @@ -109,6 +109,22 @@ static int io_waitid_finish(struct io_kiocb *req, int ret) return ret; } +static void io_waitid_remove_wq(struct io_kiocb *req) +{ + struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); + struct wait_queue_head *head; + + head = READ_ONCE(iw->head); + if (head) { + struct io_waitid_async *iwa = req->async_data; + + iw->head = NULL; + spin_lock_irq(&head->lock); + list_del_init(&iwa->wo.child_wait.entry); + spin_unlock_irq(&head->lock); + } +} + static void io_waitid_complete(struct io_kiocb *req, int ret) { struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); @@ -119,6 +135,7 @@ static void io_waitid_complete(struct io_kiocb *req, int ret) lockdep_assert_held(&req->ctx->uring_lock); hlist_del_init(&req->hash_node); + io_waitid_remove_wq(req); ret = io_waitid_finish(req, ret); if (ret < 0) @@ -129,7 +146,8 @@ static void io_waitid_complete(struct io_kiocb *req, int ret) static bool __io_waitid_cancel(struct io_kiocb *req) { struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); - struct io_waitid_async *iwa = req->async_data; + + lockdep_assert_held(&req->ctx->uring_lock); /* * Mark us canceled regardless of ownership. This will prevent a @@ -141,9 +159,6 @@ static bool __io_waitid_cancel(struct io_kiocb *req) if (atomic_fetch_inc(&iw->refs) & IO_WAITID_REF_MASK) return false; - spin_lock_irq(&iw->head->lock); - list_del_init(&iwa->wo.child_wait.entry); - spin_unlock_irq(&iw->head->lock); io_waitid_complete(req, -ECANCELED); io_req_queue_tw_complete(req, -ECANCELED); return true; @@ -209,8 +224,7 @@ static void io_waitid_cb(struct io_kiocb *req, io_tw_token_t tw) io_waitid_drop_issue_ref(req); return; } - - remove_wait_queue(iw->head, &iwa->wo.child_wait); + /* fall through to complete, will kill waitqueue */ } } -- 2.47.3