From patchwork Tue Mar 3 17:41:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229863 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B0A2C3F2D1 for ; Tue, 3 Mar 2020 18:13:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 477212073B for ; Tue, 3 Mar 2020 18:13:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583259227; bh=bwqt22GXErc9LKOF1ZlvL4ihh4c3qNfF8vE522rf70Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=juhlSa2b5NoPKHJWIDtl90lqpceSn4oVDeAFwC2ZGYYdbmUBlDGg7U/jipqd+bFOZ S5Fa0xDPlu61HvFNmuR/udWZO43mVeN0m3d+bxH8S+CiU75IjESWtKYyHyfKOfSYVp 3WYIaqoDWDRACigtUwGsM/6KGiYhUQBqpl7jc7Os= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730972AbgCCRpl (ORCPT ); Tue, 3 Mar 2020 12:45:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:51892 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730969AbgCCRpl (ORCPT ); Tue, 3 Mar 2020 12:45:41 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2915221741; Tue, 3 Mar 2020 17:45:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583257540; bh=bwqt22GXErc9LKOF1ZlvL4ihh4c3qNfF8vE522rf70Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kngaOYW4Od4ovJiVe2Y6dkv2rOJCcYULV4Evv6BRAPrqeytszhyc+Dggd+pTMkIZP kn26adcuepTZp5MZpJ/p5M9en5SdTi9eIfeVPXiJANBNY/rdU2lNbxf+miJpaeGhlz R4NENvllcPuJ4Mou1wg1HjpfV6aa/6KA67uz4HNc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefano Garzarella , Jens Axboe , Sasha Levin Subject: [PATCH 5.5 033/176] io_uring: flush overflowed CQ events in the io_uring_poll() Date: Tue, 3 Mar 2020 18:41:37 +0100 Message-Id: <20200303174308.340114195@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174304.593872177@linuxfoundation.org> References: <20200303174304.593872177@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Stefano Garzarella [ Upstream commit 63e5d81f72af1bf370bf8a6745b0a8d71a7bb37d ] In io_uring_poll() we must flush overflowed CQ events before to check if there are CQ events available, to avoid missing events. We call the io_cqring_events() that checks and flushes any overflow and returns the number of CQ events available. Signed-off-by: Stefano Garzarella Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 678c62782ba3b..de4bd647cd1df 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4970,7 +4970,7 @@ static __poll_t io_uring_poll(struct file *file, poll_table *wait) if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head != ctx->rings->sq_ring_entries) mask |= EPOLLOUT | EPOLLWRNORM; - if (READ_ONCE(ctx->rings->cq.head) != ctx->cached_cq_tail) + if (io_cqring_events(ctx, false)) mask |= EPOLLIN | EPOLLRDNORM; return mask;