From patchwork Fri Dec 6 14:45:28 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 11276651 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B224D13B6 for ; Fri, 6 Dec 2019 14:46:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 905F221835 for ; Fri, 6 Dec 2019 14:46:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=toxicpanda-com.20150623.gappssmtp.com header.i=@toxicpanda-com.20150623.gappssmtp.com header.b="qcpo8vln" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726674AbfLFOqm (ORCPT ); Fri, 6 Dec 2019 09:46:42 -0500 Received: from mail-qv1-f66.google.com ([209.85.219.66]:40062 "EHLO mail-qv1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726264AbfLFOql (ORCPT ); Fri, 6 Dec 2019 09:46:41 -0500 Received: by mail-qv1-f66.google.com with SMTP id i3so2721044qvv.7 for ; Fri, 06 Dec 2019 06:46:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20150623.gappssmtp.com; s=20150623; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=etKLBG9v+n8eeFTRJEZ/+UjoGM5jhhzFStGHRUUo6WM=; b=qcpo8vlnv0nGlyhMS2dVqFttBxwyd+ne9XhEze4X0IXmYltqsnReyuupNd7HEuib36 m/bR5AntX87fHblfOAYOPfRDee0cYySogfvsZi5MbsmkWM0BCOX6rp8TTgpFjv/S6aRi 6/Ww+RcTAOP8KbkIGi4mEtIedRVnSPezKU0lZaXEaWgKQMg81wDxSPK4zJ1EkUhqtJ25 u3VfPieD+MQPXWseyjReTkIYDGIkOiZXpF7+CqWhXdtiiF33bKeevz+9hKpTJD0nbYFO iyOyz5Yaqr6wFw0SXrYUFynwSBNmeG9RIbOkbaQY4Z8vEPjOemlmkpoi9WGDKlgB5ECw 2wrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=etKLBG9v+n8eeFTRJEZ/+UjoGM5jhhzFStGHRUUo6WM=; b=d6gxdh5KAX7KFmgwqvNRX7PDl9D7XSQbYmQK8GSwE62Z1NqauEdu7Kbzrq0qk9OOQa 74cEI9F9K4yt5I7acX3WC2ugfYI5oi2n4n5HiCrL4ln93s9NFT9m9AbPeu/D7yocFX3p e739si7kc85/gFTSu9XMCZW6rAZYgggIazWhgD18gEPyCTxBCpKCGu2GASEfaYEwmRVJ a5KX/WKBRwlQ9PyM//ZWF9zG0SyPdZAgegMvGqAira07cxVNCWlVpsIID8bcMl0i2rV9 J6lOvbZTMjLDra0Df9wfbjF9JXi+leVir6ISUrSS77qPYQlhL/aa0lxO1VS4F/p/vAgr nSSg== X-Gm-Message-State: APjAAAW1c86eHWzdysmin8mBoJQANYb0DX0B48tVG5A+8Iehn01C6wzA Dq7aG7m4/JzpS3NxM/QGjrzWD01I4MEcIw== X-Google-Smtp-Source: APXvYqzccbD9kA2630YHfQmEXvS4UkceEIiImBFfBcC1OG7D/bTZiezPCpMDwRLF26gDV8iZdeXzYg== X-Received: by 2002:a0c:e806:: with SMTP id y6mr12606851qvn.148.1575643600637; Fri, 06 Dec 2019 06:46:40 -0800 (PST) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id y184sm5996723qkd.128.2019.12.06.06.46.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Dec 2019 06:46:40 -0800 (PST) From: Josef Bacik To: linux-btrfs@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 34/44] btrfs: hold a ref on the root in get_subvol_name_from_objectid Date: Fri, 6 Dec 2019 09:45:28 -0500 Message-Id: <20191206144538.168112-35-josef@toxicpanda.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191206144538.168112-1-josef@toxicpanda.com> References: <20191206144538.168112-1-josef@toxicpanda.com> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org We lookup the name of a subvol which means we'll cross into different roots. Hold a ref while we're doing the look ups in the fs_root we're searching. Signed-off-by: Josef Bacik --- fs/btrfs/super.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index e387ca1ac0e5..9c50bee71de9 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1082,6 +1082,10 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, ret = PTR_ERR(fs_root); goto err; } + if (!btrfs_grab_fs_root(fs_root)) { + ret = -ENOENT; + goto err; + } /* * Walk up the filesystem tree by inode refs until we hit the @@ -1094,13 +1098,16 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); if (ret < 0) { + btrfs_put_fs_root(fs_root); goto err; } else if (ret > 0) { ret = btrfs_previous_item(fs_root, path, dirid, BTRFS_INODE_REF_KEY); if (ret < 0) { + btrfs_put_fs_root(fs_root); goto err; } else if (ret > 0) { + btrfs_put_fs_root(fs_root); ret = -ENOENT; goto err; } @@ -1117,6 +1124,7 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, ptr -= len + 1; if (ptr < name) { ret = -ENAMETOOLONG; + btrfs_put_fs_root(fs_root); goto err; } read_extent_buffer(path->nodes[0], ptr + 1, @@ -1124,6 +1132,7 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, ptr[0] = '/'; btrfs_release_path(path); } + btrfs_put_fs_root(fs_root); } btrfs_free_path(path);