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,URIBL_BLOCKED,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 24963C43603 for ; Wed, 11 Dec 2019 15:32:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D998424656 for ; Wed, 11 Dec 2019 15:32:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576078379; bh=MZxWCjPMdzRp2j19rWZIMdoTzcngRZidA8+i0wdeXIY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=k6a8k83ChgI5QLnNPS1KDSvmcu1huIf2n3AlKGn072asqCOZu8IYllo7nEeiuc3Fn jj7Br1g6mhyTdKlrf3TIPD7G/Lzu+IgbQyr2aDrBBbj4J6n4ecnxoDsYN2oUW262qy 2jVQh613WV/wijHyUUy6qcyNSJEGQO25oOCYl76E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387993AbfLKPc5 (ORCPT ); Wed, 11 Dec 2019 10:32:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:35180 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387719AbfLKP2t (ORCPT ); Wed, 11 Dec 2019 10:28:49 -0500 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 C97B424679; Wed, 11 Dec 2019 15:28:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576078128; bh=MZxWCjPMdzRp2j19rWZIMdoTzcngRZidA8+i0wdeXIY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CJjGn9CR4Z8TzbgNNSGZDqqpOVXNg1C5Was9EoB8tHDZIG6+bcGKVjmlplnMTCOd6 Hu5GUsKlVbfTH3Q2e//pEZGmUS60TIKoSTJ8uWzjt/V2wtXWfmgooa90mjpRMSsZZ+ 64rIVz8iamQdouWnZAbKi2Lg8venVM/Hgk9wvamw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Matthew Bobrowski , Jan Kara , Ritesh Harjani , Theodore Ts'o , Sasha Levin , linux-ext4@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 16/58] ext4: update direct I/O read lock pattern for IOCB_NOWAIT Date: Wed, 11 Dec 2019 10:27:49 -0500 Message-Id: <20191211152831.23507-16-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191211152831.23507-1-sashal@kernel.org> References: <20191211152831.23507-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Matthew Bobrowski [ Upstream commit 548feebec7e93e58b647dba70b3303dcb569c914 ] This patch updates the lock pattern in ext4_direct_IO_read() to not block on inode lock in cases of IOCB_NOWAIT direct I/O reads. The locking condition implemented here is similar to that of 942491c9e6d6 ("xfs: fix AIM7 regression"). Fixes: 16c54688592c ("ext4: Allow parallel DIO reads") Signed-off-by: Matthew Bobrowski Reviewed-by: Jan Kara Reviewed-by: Ritesh Harjani Link: https://lore.kernel.org/r/c5d5e759f91747359fbd2c6f9a36240cf75ad79f.1572949325.git.mbobrowski@mbobrowski.org Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/inode.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index b3d5fd84b4856..f746abfd96977 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3787,7 +3787,13 @@ static ssize_t ext4_direct_IO_read(struct kiocb *iocb, struct iov_iter *iter) * writes & truncates and since we take care of writing back page cache, * we are protected against page writeback as well. */ - inode_lock_shared(inode); + if (iocb->ki_flags & IOCB_NOWAIT) { + if (!inode_trylock_shared(inode)) + return -EAGAIN; + } else { + inode_lock_shared(inode); + } + ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, iocb->ki_pos + count - 1); if (ret) -- 2.20.1