From patchwork Wed Aug 2 15:41:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13338482 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 67D67C04E69 for ; Wed, 2 Aug 2023 15:43:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232378AbjHBPnb (ORCPT ); Wed, 2 Aug 2023 11:43:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234818AbjHBPma (ORCPT ); Wed, 2 Aug 2023 11:42:30 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5ACC1981; Wed, 2 Aug 2023 08:42:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=XMPneISqjawu91NBggI2WgeuEkyhCfHxDeU0xyhMo0U=; b=wnYWuPX2W/dInPzieM+5Nh7pFL yIbFDEQk+eNqVEdJoQhGrQssG8MD2wHclg6aOXifn09aXcAq8V27JW/r7ja+SWV6mZhkDFDa0CDRn 6gYzRyFjyjcdl+b9xxl1DXwN+YXWYNIQ1Jue9GjQ+XQ1GW1Fro1lrksi5uq0Ntp7kJQibSu59UXTh cIzojbnQjsVpPhFzkvrfICDJvZcqUbq5GMec/iIkf5Pd/l1XbuXi10+P9uSEM1S7AEGp5h9z1D9p7 MXW0mFULgs9ZUOsSMjkKYYaYpalbMkrjOrK9FxENDFgakDcsjltK7IL0c3TwE6zk0MvlZ3bec+4bi Z0cMSQtg==; Received: from 2a02-8389-2341-5b80-39d3-4735-9a3c-88d8.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:39d3:4735:9a3c:88d8] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qRDzJ-005GNC-2t; Wed, 02 Aug 2023 15:42:14 +0000 From: Christoph Hellwig To: Al Viro , Christian Brauner Cc: Jan Kara , Chris Mason , Josef Bacik , David Sterba , "Theodore Ts'o" , Andreas Dilger , Jaegeuk Kim , Chao Yu , Ryusuke Konishi , "Darrick J. Wong" , Jens Axboe , linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-nilfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-block@vger.kernel.org Subject: [PATCH 11/12] xfs: drop s_umount over opening the log and RT devices Date: Wed, 2 Aug 2023 17:41:30 +0200 Message-Id: <20230802154131.2221419-12-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230802154131.2221419-1-hch@lst.de> References: <20230802154131.2221419-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Just like get_tree_bdev needs to drop s_umount when opening the main device, we need to do the same for the xfs log and RT devices to avoid a potential lock order reversal with s_unmount for the mark_dead path. It might be preferable to just drop s_umount over ->fill_super entirely, but that will require a fairly massive audit first, so we'll do the easy version here first. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong --- fs/xfs/xfs_super.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 8185102431301d..d5042419ed9997 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -448,17 +448,21 @@ STATIC int xfs_open_devices( struct xfs_mount *mp) { - struct block_device *ddev = mp->m_super->s_bdev; + struct super_block *sb = mp->m_super; + struct block_device *ddev = sb->s_bdev; struct block_device *logdev = NULL, *rtdev = NULL; int error; + /* see get_tree_bdev why this is needed and safe */ + up_write(&sb->s_umount); + /* * Open real time and log devices - order is important. */ if (mp->m_logname) { error = xfs_blkdev_get(mp, mp->m_logname, &logdev); if (error) - return error; + goto out_unlock; } if (mp->m_rtname) { @@ -496,7 +500,10 @@ xfs_open_devices( mp->m_logdev_targp = mp->m_ddev_targp; } - return 0; + error = 0; +out_unlock: + down_write(&sb->s_umount); + return error; out_free_rtdev_targ: if (mp->m_rtdev_targp) @@ -508,7 +515,7 @@ xfs_open_devices( out_close_logdev: if (logdev && logdev != ddev) xfs_blkdev_put(mp, logdev); - return error; + goto out_unlock; } /*