From patchwork Thu Aug 20 09:18:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 265250 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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, 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 C20AAC433E4 for ; Thu, 20 Aug 2020 13:54:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6718F2067C for ; Thu, 20 Aug 2020 13:54:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597931682; bh=VNURiwepPfOHCYWSBAiSVCnkHz/Eyq1gIpHIveQMb1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uBxoBJIefmNeVRfsNfpxrisgaWYcd1XTT9vEUMC1dvEUCKIJsF/YTP1GB5c6CalIp YXvBt9V8cEIhBNObNf8xNXGyLDOqyw4/VuBoUEt/rnGkKciRXlR/myHRKeWHogt8t2 oGQJv44YF5aRMqYI7b5GadBoD/9KR3zLA033SZvo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730602AbgHTNyl (ORCPT ); Thu, 20 Aug 2020 09:54:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:34302 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727050AbgHTJ0R (ORCPT ); Thu, 20 Aug 2020 05:26:17 -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 B12CD2075E; Thu, 20 Aug 2020 09:26:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597915577; bh=VNURiwepPfOHCYWSBAiSVCnkHz/Eyq1gIpHIveQMb1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HU0SPkfsizh2u0hM1Tm1vAwPdFgWJhieaUtecygOmP4WtFimBVVbwE4aXb5qqdr2L a69lvBU7suEVQT5qdNXhc3GcDyhXvOnwgrep1CwTiAMzxTkEpmeixhUzR21xE6XfJ1 6aQxRydM/7m5vqqPrCTKbFdZ1zEfJ/tWU+gEkCzE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chris Murphy , Josef Bacik , David Sterba Subject: [PATCH 5.8 033/232] btrfs: dont show full path of bind mounts in subvol= Date: Thu, 20 Aug 2020 11:18:04 +0200 Message-Id: <20200820091614.367868253@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091612.692383444@linuxfoundation.org> References: <20200820091612.692383444@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Josef Bacik commit 3ef3959b29c4a5bd65526ab310a1a18ae533172a upstream. Chris Murphy reported a problem where rpm ostree will bind mount a bunch of things for whatever voodoo it's doing. But when it does this /proc/mounts shows something like /dev/sda /mnt/test btrfs rw,relatime,subvolid=256,subvol=/foo 0 0 /dev/sda /mnt/test/baz btrfs rw,relatime,subvolid=256,subvol=/foo/bar 0 0 Despite subvolid=256 being subvol=/foo. This is because we're just spitting out the dentry of the mount point, which in the case of bind mounts is the source path for the mountpoint. Instead we should spit out the path to the actual subvol. Fix this by looking up the name for the subvolid we have mounted. With this fix the same test looks like this /dev/sda /mnt/test btrfs rw,relatime,subvolid=256,subvol=/foo 0 0 /dev/sda /mnt/test/baz btrfs rw,relatime,subvolid=256,subvol=/foo 0 0 Reported-by: Chris Murphy CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/super.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1312,6 +1312,7 @@ static int btrfs_show_options(struct seq { struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); const char *compress_type; + const char *subvol_name; if (btrfs_test_opt(info, DEGRADED)) seq_puts(seq, ",degraded"); @@ -1398,8 +1399,13 @@ static int btrfs_show_options(struct seq seq_puts(seq, ",ref_verify"); seq_printf(seq, ",subvolid=%llu", BTRFS_I(d_inode(dentry))->root->root_key.objectid); - seq_puts(seq, ",subvol="); - seq_dentry(seq, dentry, " \t\n\\"); + subvol_name = btrfs_get_subvol_name_from_objectid(info, + BTRFS_I(d_inode(dentry))->root->root_key.objectid); + if (!IS_ERR(subvol_name)) { + seq_puts(seq, ",subvol="); + seq_escape(seq, subvol_name, " \t\n\\"); + kfree(subvol_name); + } return 0; }