From mboxrd@z Thu Jan 1 00:00:00 1970 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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 E7343C433E0 for ; Thu, 18 Jun 2020 02:32:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C8426206E2 for ; Thu, 18 Jun 2020 02:32:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592447547; bh=xbcdMyZ/zU7XdYMLaTEcniBciHD6hTU30WYvpM9EXOc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HQKrjGnLjsXKMsGHwoiRyY00S+mcuRZ/3sX1ud/OPeoldGBaHlGnXo0a2ARsSf/Ij XNohjFo+8FKyyKwQzfGb0hInGuPctEEFjgiowUT+Ap8/mzNWU2JPxTiqdryTlrK/Iy i+uaUdb9BVi7RbM+UbyxEt/DdlqPVXi3cezGiB6I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729601AbgFRCc0 (ORCPT ); Wed, 17 Jun 2020 22:32:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:45246 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729445AbgFRBPN (ORCPT ); Wed, 17 Jun 2020 21:15:13 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E101C221EB; Thu, 18 Jun 2020 01:15:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592442913; bh=xbcdMyZ/zU7XdYMLaTEcniBciHD6hTU30WYvpM9EXOc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FUasuUFcD3ZJB5r0rJL5sumgGxjBjfF51E/VhLCQWmlooTNbubu6VDkr3ZehHXr+G onhoOct+OkdGSwJ3j4UkSwym1s70E6B84resIjSSVj/1MQaujfpt/yiDcULXv9SnPT kQ4UPvc+rLBkwB+8MIlBBMBvgojOwgwyeGOzKrfA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jens Axboe , Theodore Ts'o , Sasha Levin , linux-ext4@vger.kernel.org Subject: [PATCH AUTOSEL 5.7 331/388] ext4: don't block for O_DIRECT if IOCB_NOWAIT is set Date: Wed, 17 Jun 2020 21:07:08 -0400 Message-Id: <20200618010805.600873-331-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200618010805.600873-1-sashal@kernel.org> References: <20200618010805.600873-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jens Axboe [ Upstream commit 6e014c621e7271649f0d51e54dbe1db4c10486c8 ] Running with some debug patches to detect illegal blocking triggered the extend/unaligned condition in ext4. If ext4 needs to extend the file (and hence go to buffered IO), or if the app is doing unaligned IO, then ext4 asks the iomap code to wait for IO completion. If the caller asked for no-wait semantics by setting IOCB_NOWAIT, then ext4 should return -EAGAIN instead. Signed-off-by: Jens Axboe Link: https://lore.kernel.org/r/76152096-2bbb-7682-8fce-4cb498bcd909@kernel.dk Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/file.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index b8e69f9e3858..2a01e31a032c 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -502,6 +502,12 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) if (ret <= 0) return ret; + /* if we're going to block and IOCB_NOWAIT is set, return -EAGAIN */ + if ((iocb->ki_flags & IOCB_NOWAIT) && (unaligned_io || extend)) { + ret = -EAGAIN; + goto out; + } + offset = iocb->ki_pos; count = ret; -- 2.25.1