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 4613DC2D0C6 for ; Wed, 11 Dec 2019 15:44:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1AF26208C3 for ; Wed, 11 Dec 2019 15:44:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576079099; bh=Ij6qeap0hI6cFj/+9nasKGNk7xnnnew3c0gdzp7vhk8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GLK+Ewl7NEENIK4eGvDTz6UeIB1V6vlM6RhpPS3L3eqzh/B6iNTsXE6GUzRSEfOZ+ S+6roRdX3D2oNoV2+04MJW/kCcCdq0QNE59GQ0dG7/TKxJHXHoBChkO7+pohHoefKu CQe/9hEmcCv96A15IEp1U6k0eFn2FbSafV195U2M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733302AbfLKP1S (ORCPT ); Wed, 11 Dec 2019 10:27:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:60874 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733249AbfLKP1J (ORCPT ); Wed, 11 Dec 2019 10:27:09 -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 E0E082173E; Wed, 11 Dec 2019 15:27:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576078028; bh=Ij6qeap0hI6cFj/+9nasKGNk7xnnnew3c0gdzp7vhk8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Pv/16BXy/j7OhieDdsEVXRERHQyYdG/k+KPPodQnTnpnJDV3HgEC4W18ISxAQyErF Y+PNOV+mdSEcgBQEyYWYrk5r7ajYupV1z/baPuDewxNXOV3XS8/+U/bNscQQpzAkHw hSZE9CkGXI+i5h4ejbyXC+VLq1rlP8T+ESk02bxc= 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 4.19 23/79] ext4: update direct I/O read lock pattern for IOCB_NOWAIT Date: Wed, 11 Dec 2019 10:25:47 -0500 Message-Id: <20191211152643.23056-23-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191211152643.23056-1-sashal@kernel.org> References: <20191211152643.23056-1-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: 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 f8a0af11a31e8..00d25a0643913 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3839,7 +3839,13 @@ 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