From patchwork Sun Jan 15 14:48:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Yang X-Patchwork-Id: 13102276 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFEFDC63797 for ; Sun, 15 Jan 2023 14:49:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231327AbjAOOtR (ORCPT ); Sun, 15 Jan 2023 09:49:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43932 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230322AbjAOOtM (ORCPT ); Sun, 15 Jan 2023 09:49:12 -0500 Received: from out162-62-57-252.mail.qq.com (out162-62-57-252.mail.qq.com [162.62.57.252]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6304F10401; Sun, 15 Jan 2023 06:49:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foxmail.com; s=s201512; t=1673794143; bh=ndxiOKIjgMog/hMr4F9xvx2c1YwIDASPYXvZJKXmyfg=; h=From:To:Cc:Subject:Date; b=MjZRB76581YOWXPquSibalgaepyv0r2leB0d7VhYYoeFMwA2uS6oRWR3Us4KZAErm 8l/b53y95jRNe1v2J1+1C7qeAuVQ0Emn4OGdc9omJePDkp1MY9c+aO/QLVUALiECsT dyxvHllwuPv5kYhyo2G3XjhR2/k4Dih37QlUf7eE= Received: from localhost.localdomain ([119.4.52.193]) by newxmesmtplogicsvrsza10-0.qq.com (NewEsmtp) with SMTP id C41B8881; Sun, 15 Jan 2023 22:49:01 +0800 X-QQ-mid: xmsmtpt1673794141t4gkux1a8 Message-ID: X-QQ-XMAILINFO: OKkKo7I1HxIeJ98xPC2ML3gxFdU9GLYGLIJpFY6vbaR9HG+2YTSlQeNnZX6DLb ypj1mQKa+3bunvAFHycNbTWFcJb0vtW3ODdtiQM0ThhY7UrnEJzPbdQkilLP8AElJnRcVvc51Xvf qgeSoeX0ICRgnlTSRHWovj/9Tjx8gCPWaXWEaWGOmzDSlzmPD7uj2TaZ9uvFdcJwZJV8UBauT916 i7o2j3OKzl179IDiXs2eAZc53Zs3oUt56uURkOcb3Wlo1kMDW11UndPJ2tbhEijNuSmPV/LB5mpx XFmZI5xNGGu+jLOLL2m1yckbBVXcFvJhcqbZxbQqwXqDnUPxo4p5f20oEBBA9R/giO3ZIjjKHiCT afbES7PnVCXwnhfFdJdRVgOpQ8cCRh5bSkZUwqP/oGlo/xwzI4vCUB9bWM3QSaxtph+M1LwSIjr8 tLTNNICrMXgNr1U78uIrn14M2oCczfigG2QReV7tlIv3KqDQTV7eKxVyP5CjZRqSTRnYEkiiCgJG TPwOw33K3gw95A1LnJ54SwH2apzf/vTgFX9jVjMIbV3ESw8WLj9Nx+aAwb2eY3/MNL0kLjzn/csr iykufJr1GFnA0OkaQ9kaUJFNz1EYS7xCVvoh421urNAH2kTuD9O0Q+Nu9x2t7B/0r1AX/82900ik Yr7ebZgOfdsSkloGnYl8EF6gnxhGEpwr59/+IZkFtylaChozbV+WoeTYumL/dbcnSxGcqRmECM/5 QfYhWthFXTNSf3XETAAR2n2TXBrOPulGyFoOchhhf4rzMIqH6dcpOV5TdG+hTzOLFqAzGLHslKN5 m8jOVLlHr7lENggsYUgkxVDcLiCRP6m9vt0kw1Lrl4CdZUmGAFeQaYagmEvXOG5SCsL22D6bUFmP IjSWAwK3BJbsK6C+dJsWybDE1Bh+lGLKmFSWL4KjREkX7wEsfBTQXoRoIYobRb4gG8U1UDt55XYA 1OPwcawgSUdmE23hA7Q2R2vw3scoq7 From: wenyang.linux@foxmail.com To: Alexander Viro Cc: Wen Yang , kernel test robot , Dan Carpenter , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RESEND PATCH v2] eventfd: use a generic helper instead of an open coded wait_event Date: Sun, 15 Jan 2023 22:48:29 +0800 X-OQ-MSGID: <20230115144829.9786-1-wenyang.linux@foxmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Wen Yang Use wait_event_interruptible_locked_irq() in the eventfd_{write,read} to avoid the longer, open coded equivalent. Signed-off-by: Wen Yang Cc: Alexander Viro Cc: kernel test robot Cc: Dan Carpenter Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- v2: - fix smatch warnings: eventfd_read() warn: inconsistent returns '&ctx->wqh.lock'. fs/eventfd.c | 41 +++++++---------------------------------- 1 file changed, 7 insertions(+), 34 deletions(-) diff --git a/fs/eventfd.c b/fs/eventfd.c index 249ca6c0b784..c5bda3df4a28 100644 --- a/fs/eventfd.c +++ b/fs/eventfd.c @@ -228,7 +228,6 @@ static ssize_t eventfd_read(struct kiocb *iocb, struct iov_iter *to) struct file *file = iocb->ki_filp; struct eventfd_ctx *ctx = file->private_data; __u64 ucnt = 0; - DECLARE_WAITQUEUE(wait, current); if (iov_iter_count(to) < sizeof(ucnt)) return -EINVAL; @@ -239,23 +238,11 @@ static ssize_t eventfd_read(struct kiocb *iocb, struct iov_iter *to) spin_unlock_irq(&ctx->wqh.lock); return -EAGAIN; } - __add_wait_queue(&ctx->wqh, &wait); - for (;;) { - set_current_state(TASK_INTERRUPTIBLE); - if (ctx->count) - break; - if (signal_pending(current)) { - __remove_wait_queue(&ctx->wqh, &wait); - __set_current_state(TASK_RUNNING); - spin_unlock_irq(&ctx->wqh.lock); - return -ERESTARTSYS; - } + + if (wait_event_interruptible_locked_irq(ctx->wqh, ctx->count)) { spin_unlock_irq(&ctx->wqh.lock); - schedule(); - spin_lock_irq(&ctx->wqh.lock); + return -ERESTARTSYS; } - __remove_wait_queue(&ctx->wqh, &wait); - __set_current_state(TASK_RUNNING); } eventfd_ctx_do_read(ctx, &ucnt); current->in_eventfd = 1; @@ -275,7 +262,6 @@ static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t c struct eventfd_ctx *ctx = file->private_data; ssize_t res; __u64 ucnt; - DECLARE_WAITQUEUE(wait, current); if (count < sizeof(ucnt)) return -EINVAL; @@ -288,23 +274,10 @@ static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t c if (ULLONG_MAX - ctx->count > ucnt) res = sizeof(ucnt); else if (!(file->f_flags & O_NONBLOCK)) { - __add_wait_queue(&ctx->wqh, &wait); - for (res = 0;;) { - set_current_state(TASK_INTERRUPTIBLE); - if (ULLONG_MAX - ctx->count > ucnt) { - res = sizeof(ucnt); - break; - } - if (signal_pending(current)) { - res = -ERESTARTSYS; - break; - } - spin_unlock_irq(&ctx->wqh.lock); - schedule(); - spin_lock_irq(&ctx->wqh.lock); - } - __remove_wait_queue(&ctx->wqh, &wait); - __set_current_state(TASK_RUNNING); + res = wait_event_interruptible_locked_irq(ctx->wqh, + ULLONG_MAX - ctx->count > ucnt); + if (!res) + res = sizeof(ucnt); } if (likely(res > 0)) { ctx->count += ucnt;