From patchwork Thu May 16 14:45:56 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Behrens X-Patchwork-Id: 2578381 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id A39CBDFB7B for ; Thu, 16 May 2013 14:46:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754602Ab3EPOqF (ORCPT ); Thu, 16 May 2013 10:46:05 -0400 Received: from xp-ob.rzone.de ([81.169.146.137]:25525 "EHLO xp-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754549Ab3EPOp7 (ORCPT ); Thu, 16 May 2013 10:45:59 -0400 X-RZG-CLASS-ID: xp Received: from pizpot.store ([192.168.43.236]) by josoe.store (josoe xp1) (RZmta 31.27 OK) with ESMTP id X07dfap4G8bU4v for ; Thu, 16 May 2013 16:45:58 +0200 (CEST) From: Stefan Behrens To: linux-btrfs@vger.kernel.org Subject: [PATCH v3 2/4] Btrfs-progs: add UUID tree lookup methods Date: Thu, 16 May 2013 16:45:56 +0200 Message-Id: <850b602748927f8f79e5ed5d3ad8712838757ce1.1368713962.git.sbehrens@giantdisaster.de> X-Mailer: git-send-email 1.8.2.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This commit adds UUID tree lookup methods that make use of the search ioctl. The code is based on the kernel code. Signed-off-by: Stefan Behrens --- Makefile | 5 +- ctree.h | 5 ++ uuid-tree.c | 174 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 182 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 7d4faba..66eefb7 100644 --- a/Makefile +++ b/Makefile @@ -6,12 +6,13 @@ CFLAGS = -g -O1 objects = ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \ root-tree.o dir-item.o file-item.o inode-item.o inode-map.o \ extent-cache.o extent_io.o volumes.o utils.o repair.o \ - qgroup.o raid6.o free-space-cache.o + qgroup.o raid6.o free-space-cache.o uuid-tree.o cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \ cmds-inspect.o cmds-balance.o cmds-send.o cmds-receive.o \ cmds-quota.o cmds-qgroup.o cmds-replace.o cmds-check.o \ cmds-restore.o -libbtrfs_objects = send-stream.o send-utils.o rbtree.o btrfs-list.o crc32c.o +libbtrfs_objects = send-stream.o send-utils.o rbtree.o btrfs-list.o crc32c.o \ + uuid-tree.o libbtrfs_headers = send-stream.h send-utils.h send.h rbtree.h btrfs-list.h \ crc32c.h list.h kerncompat.h radix-tree.h extent-cache.h \ extent_io.h ioctl.h ctree.h diff --git a/ctree.h b/ctree.h index 0f14b41..e36cb17 100644 --- a/ctree.h +++ b/ctree.h @@ -2355,4 +2355,9 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans, int btrfs_csum_truncate(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 isize); + +/* uuid-tree.c */ +int btrfs_lookup_uuid_subvol_item(int fd, const u8 *uuid, u64 *subvol_id); +int btrfs_lookup_uuid_received_subvol_item(int fd, const u8 *uuid, + u64 *subvol_id); #endif diff --git a/uuid-tree.c b/uuid-tree.c new file mode 100644 index 0000000..fcd270e --- /dev/null +++ b/uuid-tree.c @@ -0,0 +1,174 @@ +/* + * Copyright (C) STRATO AG 2013. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ +#include +#include +#include +#include +#include "ctree.h" +#include "transaction.h" +#include "disk-io.h" +#include "print-tree.h" + + +/* + * One key is used to store a sequence of btrfs_uuid_item items. + * Each item in the sequence contains a type information and a sequence of + * ids (together with the information about the size of the sequence of ids). + * {[btrfs_uuid_item type0 {id0, id1, ..., idN}], + * ..., + * [btrfs_uuid_item typeZ {id0, id1, ..., idN}]} + * + * It is forbidden to put multiple items with the same type under the same key. + * Instead the sequence of ids is extended and used to store any additional + * ids for the same item type. + */ + +static void btrfs_uuid_to_key(const u8 *uuid, u64 *key_objectid, + u64 *key_offset) +{ + *key_objectid = get_unaligned_le64(uuid); + *key_offset = get_unaligned_le64(uuid + sizeof(u64)); +} + +static struct btrfs_uuid_item *btrfs_match_uuid_item_type( + struct btrfs_uuid_item *ptr, u32 item_size, u16 type) +{ + do { + u16 sub_item_type; + u64 sub_item_len; + + if (item_size < sizeof(*ptr)) { + fprintf(stderr, + "btrfs: uuid item too short (%lu < %d)!\n", + (unsigned long)item_size, (int)sizeof(*ptr)); + return NULL; + } + item_size -= sizeof(*ptr); + sub_item_type = btrfs_stack_uuid_type(ptr); + sub_item_len = btrfs_stack_uuid_len(ptr); + if (sub_item_len * sizeof(u64) > item_size) { + fprintf(stderr, + "btrfs: uuid item too short (%llu > %lu)!\n", + (unsigned long long) + (sub_item_len * sizeof(u64)), + (unsigned long)item_size); + return NULL; + } + if (sub_item_type == type) + return ptr; + item_size -= sub_item_len * sizeof(u64); + ptr = 1 + (struct btrfs_uuid_item *) + (((char *)ptr) + (sub_item_len * sizeof(u64))); + } while (item_size); + + return NULL; +} + +static int btrfs_uuid_tree_lookup_prepare(int fd, const u8 *uuid, u16 type, + struct btrfs_ioctl_search_args + *search_arg, + struct btrfs_uuid_item **ptr) +{ + int ret; + u64 key_objectid = 0; + u64 key_offset; + struct btrfs_uuid_item *uuid_item; + struct btrfs_ioctl_search_header *search_header; + u32 item_size; + + btrfs_uuid_to_key(uuid, &key_objectid, &key_offset); + + memset(search_arg, 0, sizeof(*search_arg)); + search_arg->key.tree_id = BTRFS_UUID_TREE_OBJECTID; + search_arg->key.min_objectid = key_objectid; + search_arg->key.max_objectid = key_objectid; + search_arg->key.min_type = BTRFS_UUID_KEY; + search_arg->key.max_type = BTRFS_UUID_KEY; + search_arg->key.min_offset = key_offset; + search_arg->key.max_offset = key_offset; + search_arg->key.max_transid = (u64)-1; + search_arg->key.nr_items = 1; + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, search_arg); + if (ret < 0) { + fprintf(stderr, + "ioctl(BTRFS_IOC_TREE_SEARCH, uuid, key %016llx, UUID_KEY, %016llx) ret=%d, error: %s\n", + (unsigned long long)key_objectid, + (unsigned long long)key_offset, ret, strerror(errno)); + ret = -ENOENT; + goto out; + } + + if (search_arg->key.nr_items < 1) { + ret = -ENOENT; + goto out; + } + search_header = (struct btrfs_ioctl_search_header *)(search_arg->buf); + uuid_item = (struct btrfs_uuid_item *)(search_header + 1); + item_size = search_header->len; + + *ptr = btrfs_match_uuid_item_type(uuid_item, item_size, type); + if (!*ptr) { + ret = -ENOENT; + goto out; + } + + ret = 0; + +out: + return ret; +} + +/* return -ENOENT for !found, < 0 for errors, or 0 if an item was found */ +static int btrfs_uuid_tree_lookup_any(int fd, const u8 *uuid, u16 type, + u64 *subid) +{ + int ret; + struct btrfs_ioctl_search_args search_arg; + struct btrfs_uuid_item *ptr; + u32 sub_item_len; + + ret = btrfs_uuid_tree_lookup_prepare(fd, uuid, type, &search_arg, &ptr); + if (ret) + goto out; + + sub_item_len = btrfs_stack_uuid_len(ptr); + if (sub_item_len > 0) { + /* return first stored id */ + memcpy(subid, ptr + 1, sizeof(*subid)); + *subid = le64_to_cpu(*subid); + } else { + ret = -ENOENT; + } + +out: + return ret; +} + +int btrfs_lookup_uuid_subvol_item(int fd, const u8 *uuid, u64 *subvol_id) +{ + return btrfs_uuid_tree_lookup_any(fd, uuid, BTRFS_UUID_ITEM_TYPE_SUBVOL, + subvol_id); +} + +int btrfs_lookup_uuid_received_subvol_item(int fd, const u8 *uuid, + u64 *subvol_id) +{ + return btrfs_uuid_tree_lookup_any(fd, uuid, + BTRFS_UUID_ITEM_TYPE_RECEIVED_SUBVOL, + subvol_id); +}