From patchwork Wed Jun 24 16:03:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 11623571 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 34483618 for ; Wed, 24 Jun 2020 16:03:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D0F12077D for ; Wed, 24 Jun 2020 16:03:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=nic.cz header.i=@nic.cz header.b="j5pTG526" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404802AbgFXQDf (ORCPT ); Wed, 24 Jun 2020 12:03:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404789AbgFXQD3 (ORCPT ); Wed, 24 Jun 2020 12:03:29 -0400 Received: from mail.nic.cz (mail.nic.cz [IPv6:2001:1488:800:400::400]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3DC6C061796 for ; Wed, 24 Jun 2020 09:03:28 -0700 (PDT) Received: from dellmb.labs.office.nic.cz (unknown [IPv6:2001:1488:fffe:6:cac7:3539:7f1f:463]) by mail.nic.cz (Postfix) with ESMTP id F0EDD1409AD; Wed, 24 Jun 2020 18:03:25 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nic.cz; s=default; t=1593014606; bh=aA1AqkkVCkm0RXPcoJ+3RjIZ/FYumKZ+5DLnKkpQM+k=; h=From:To:Date; b=j5pTG5266Te+rDSXZ9I9WDyb5WUMKbhCRB5F5U6Pcge9oLhu6tylVnm7S1ggaLWqi A24KYzTi0EOdQzTY6zkWhmzQeoclQ4I0qdj0GLHda89oMYIkZ4hvGj9VXYlYwB9qEb ybWhv+sSuAEHqPTeCQwmNbdSh2VRU4Uxx19YBAWc= From: =?utf-8?q?Marek_Beh=C3=BAn?= To: u-boot@lists.denx.de Cc: =?utf-8?q?Alberto_S=C3=A1nchez_Molero?= , Marek Vasut , Pierre Bourdon , Simon Glass , Tom Rini , Yevgeny Popovych , linux-btrfs@vger.kernel.org, Qu Wenruo , =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH U-BOOT v3 27/30] fs: btrfs: Introduce function to resolve the path of one subvolume Date: Wed, 24 Jun 2020 18:03:13 +0200 Message-Id: <20200624160316.5001-28-marek.behun@nic.cz> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200624160316.5001-1-marek.behun@nic.cz> References: <20200624160316.5001-1-marek.behun@nic.cz> MIME-Version: 1.0 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on mail.nic.cz X-Spam-Status: No, score=0.00 X-Spamd-Bar: / X-Virus-Scanned: clamav-milter 0.102.2 at mail X-Virus-Status: Clean Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Qu Wenruo This patch introduces a new function, list_one_subvol(), which will resolve the path to FS_TREE of one subvolume. Signed-off-by: Qu Wenruo Reviewed-by: Marek Behún --- fs/btrfs/subvolume.c | 81 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/fs/btrfs/subvolume.c b/fs/btrfs/subvolume.c index b446e729cd..258c3dafef 100644 --- a/fs/btrfs/subvolume.c +++ b/fs/btrfs/subvolume.c @@ -8,6 +8,7 @@ #include #include "ctree.h" #include "btrfs.h" +#include "disk-io.h" /* * Resolve the path of ino inside subvolume @root into @path_ret. @@ -74,6 +75,86 @@ out: return ret; } +static int list_one_subvol(struct btrfs_root *root, char *path_ret) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_root *tree_root = fs_info->tree_root; + struct btrfs_path path; + struct btrfs_key key; + char *tmp; + u64 cur = root->root_key.objectid; + int ret = 0; + + tmp = malloc(PATH_MAX); + if (!tmp) + return -ENOMEM; + tmp[0] = '\0'; + path_ret[0] = '\0'; + btrfs_init_path(&path); + while (cur != BTRFS_FS_TREE_OBJECTID) { + struct btrfs_root_ref *rr; + struct btrfs_key location; + int name_len; + u64 ino; + + key.objectid = cur; + key.type = BTRFS_ROOT_BACKREF_KEY; + key.offset = (u64)-1; + btrfs_release_path(&path); + + ret = btrfs_search_slot(NULL, tree_root, &key, &path, 0, 0); + if (ret == 0) + ret = -EUCLEAN; + if (ret < 0) + goto out; + ret = btrfs_previous_item(tree_root, &path, cur, + BTRFS_ROOT_BACKREF_KEY); + if (ret > 0) + ret = -ENOENT; + if (ret < 0) + goto out; + + /* Get the subvolume name */ + rr = btrfs_item_ptr(path.nodes[0], path.slots[0], + struct btrfs_root_ref); + strncpy(tmp, path_ret, PATH_MAX); + name_len = btrfs_root_ref_name_len(path.nodes[0], rr); + if (name_len > BTRFS_NAME_LEN) { + ret = -ENAMETOOLONG; + goto out; + } + ino = btrfs_root_ref_dirid(path.nodes[0], rr); + read_extent_buffer(path.nodes[0], path_ret, + (unsigned long)(rr + 1), name_len); + path_ret[name_len] = '/'; + path_ret[name_len + 1] = '\0'; + strncat(path_ret, tmp, PATH_MAX); + + /* Get the path inside the parent subvolume */ + btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]); + location.objectid = key.offset; + location.type = BTRFS_ROOT_ITEM_KEY; + location.offset = (u64)-1; + root = btrfs_read_fs_root(fs_info, &location); + if (IS_ERR(root)) { + ret = PTR_ERR(root); + goto out; + } + ret = get_path_in_subvol(root, ino, path_ret); + if (ret < 0) + goto out; + cur = key.offset; + } + /* Add the leading '/' */ + strncpy(tmp, path_ret, PATH_MAX); + strncpy(path_ret, "/", PATH_MAX); + strncat(path_ret, tmp, PATH_MAX); +out: + btrfs_release_path(&path); + free(tmp); + return ret; +} + static int get_subvol_name(u64 subvolid, char *name, int max_len) { struct btrfs_root_ref rref;