From patchwork Fri Jan 24 14:32:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 11350431 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 41837924 for ; Fri, 24 Jan 2020 14:34:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1FA8020838 for ; Fri, 24 Jan 2020 14:34:05 +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="oRRHd2ZS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404639AbgAXOeC (ORCPT ); Fri, 24 Jan 2020 09:34:02 -0500 Received: from mail-qv1-f67.google.com ([209.85.219.67]:36871 "EHLO mail-qv1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404591AbgAXOeB (ORCPT ); Fri, 24 Jan 2020 09:34:01 -0500 Received: by mail-qv1-f67.google.com with SMTP id f16so983132qvi.4 for ; Fri, 24 Jan 2020 06:34:01 -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=v3jy/bucDHb1mxW6er9m37yXCMVg9C8Ly2cHcVVVXag=; b=oRRHd2ZSLlbBOFg70OvhtuuF1mK5Xpi38c2ky89qMMeEmYbOX7qS5iMWX/K9Vl0wYG 77rnxKra5OYP1DyERCg4zeerP6m/uqdT9fsVKwAmE3kdOhuExA5xrz+aK3vQMHBHcdqz 2UJftnNnK+kTsUyi+ZLVOiyBWr82UIoi9pr85vT4dhWIUKJRD6v92X+8LDYemiHhMO/k VtUeIc0TiwmUVNMW0yrOeDLMFezCuq2OzBQMjgAvXfq67r95Af+54RBLg1IGinecO/Bp zlSxUCy2mi+X+DW7v8f02SyAe2ovzSTyYkb/67Fd0GtI2a3sULexVQgvXgRRftPndvBT nWKg== 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=v3jy/bucDHb1mxW6er9m37yXCMVg9C8Ly2cHcVVVXag=; b=bIHn/+9Pmgk3NvIeVmFQzi1xZLQ8FfAOAQtx3+BZolKCqoZAhQrviqdN5leopHN3bu 8M2bXSUjD7MF3qOv8M7tWq8nTkksBh0FRlxCUbpuzxTXIAVo43u9uA2yw7ru7hgpO9/w lQXPaLvpkxh72YASaKcUIDQQDL4XFNQNsWOdBBQNkjYZMbW5MdZTrr9hINnHcXEzganx eSHW1Kk0iPYm4PsqYzQhLG8YxMoDK6QiKTKG9LgQXQzRh3iYT8uyBCtO0D/mYSYhvg6V HZ4t41DYIogMk4dOHjA6NUofKGLJ1Hv5Oy9jafw+bbirybJGc1pXPZ4PgOpG+cx9eo0I mhrA== X-Gm-Message-State: APjAAAXyGXMy9gTkTKawvCuzEZU9+N/+iJmP6vvjs30IqTnw37bvEZIJ JHfNqmjmEtvyPjv/TEw7mUwXsWaBnmJZLA== X-Google-Smtp-Source: APXvYqyiIDv4PxTtwydJWapt/rMVhGeDIZ8/nsp2JjS0CRt4mtSKfWcPMScrQrF4RcJRESYTjHI1aw== X-Received: by 2002:a05:6214:13a3:: with SMTP id h3mr3060286qvz.212.1579876440654; Fri, 24 Jan 2020 06:34:00 -0800 (PST) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id f28sm1336368qkk.130.2020.01.24.06.33.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 24 Jan 2020 06:34:00 -0800 (PST) From: Josef Bacik To: kernel-team@fb.com, linux-btrfs@vger.kernel.org Subject: [PATCH 32/44] btrfs: hold a ref on the root in get_subvol_name_from_objectid Date: Fri, 24 Jan 2020 09:32:49 -0500 Message-Id: <20200124143301.2186319-33-josef@toxicpanda.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200124143301.2186319-1-josef@toxicpanda.com> References: <20200124143301.2186319-1-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 3118bc01321e..5c3a1b7de6ee 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1101,6 +1101,10 @@ 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 @@ -1113,13 +1117,16 @@ 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; } @@ -1136,6 +1143,7 @@ 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, @@ -1143,6 +1151,7 @@ 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);