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=-10.0 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,URIBL_BLOCKED,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 15BACC433DF for ; Tue, 23 Jun 2020 21:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E02BD20781 for ; Tue, 23 Jun 2020 21:29:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592947798; bh=/0jXKY3TJ2pVhw3ClEqAeO1O7QusWNrVVyNMLtWUTJ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZuIQs+6QAi4Z0fZEJCWEEvwEG00fM3Y536L6uF6Cjic8OB3wLHt5vw+ssAylKEaIz K/9FkUHh3vAzvLHZP3WVHHquinD0iS39BYckmVQikfuc7YMwOr921jU4RhSu4wjlAz HbHFcU3eolLODkfRZtstZFu+eZWDK65wBGGDDi1Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388922AbgFWUOY (ORCPT ); Tue, 23 Jun 2020 16:14:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:56712 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388911AbgFWUOX (ORCPT ); Tue, 23 Jun 2020 16:14:23 -0400 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 9FAB52073E; Tue, 23 Jun 2020 20:14:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592943263; bh=/0jXKY3TJ2pVhw3ClEqAeO1O7QusWNrVVyNMLtWUTJ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ydqIet8HtrqF5I6ZM2OTMkxSqg2+IQxrsiy6/NKNUztKxV6uGAGERXaXaO3t9OhUJ CcKfsFiGoSqbpb+guBj0+oyz2ZWuQ+fmpTkGUolrCSJZR2g2h7ZANooaPFKb8JBEjn UPR43IWLCasM0IcQTghTDwZetJeJErbP1U4BvfEc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jens Axboe , Theodore Tso , Sasha Levin Subject: [PATCH 5.7 323/477] ext4: dont block for O_DIRECT if IOCB_NOWAIT is set Date: Tue, 23 Jun 2020 21:55:20 +0200 Message-Id: <20200623195422.801381152@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200623195407.572062007@linuxfoundation.org> References: <20200623195407.572062007@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 b8e69f9e38587..2a01e31a032c4 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