2 * Copyright (C) 2011 Red Hat. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #define _XOPEN_SOURCE 500
27 #include "kerncompat.h"
30 #include "print-tree.h"
31 #include "transaction.h"
38 static u16 csum_size = 0;
39 static u64 search_objectid = BTRFS_ROOT_TREE_OBJECTID;
43 fprintf(stderr, "Usage: find-roots [-o search_objectid] <device>\n");
46 int csum_block(void *buf, u32 len)
52 result = malloc(csum_size * sizeof(char));
54 fprintf(stderr, "No memory\n");
58 len -= BTRFS_CSUM_SIZE;
59 crc = crc32c(crc, buf + BTRFS_CSUM_SIZE, len);
60 btrfs_csum_final(crc, result);
62 if (memcmp(buf, result, csum_size))
68 static int close_all_devices(struct btrfs_fs_info *fs_info)
70 struct list_head *list;
71 struct list_head *next;
72 struct btrfs_device *device;
76 list = &fs_info->fs_devices->devices;
77 list_for_each(next, list) {
78 device = list_entry(next, struct btrfs_device, dev_list);
84 static struct btrfs_root *open_ctree_broken(int fd, const char *device)
92 struct btrfs_root *tree_root = malloc(sizeof(struct btrfs_root));
93 struct btrfs_root *extent_root = malloc(sizeof(struct btrfs_root));
94 struct btrfs_root *chunk_root = malloc(sizeof(struct btrfs_root));
95 struct btrfs_root *dev_root = malloc(sizeof(struct btrfs_root));
96 struct btrfs_root *csum_root = malloc(sizeof(struct btrfs_root));
97 struct btrfs_fs_info *fs_info = malloc(sizeof(*fs_info));
99 struct btrfs_super_block *disk_super;
100 struct btrfs_fs_devices *fs_devices = NULL;
104 ret = btrfs_scan_one_device(fd, device, &fs_devices,
105 &total_devs, BTRFS_SUPER_INFO_OFFSET);
108 fprintf(stderr, "No valid Btrfs found on %s\n", device);
112 if (total_devs != 1) {
113 ret = btrfs_scan_for_fsid(fs_devices, total_devs, 1);
118 memset(fs_info, 0, sizeof(*fs_info));
119 fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
120 fs_info->tree_root = tree_root;
121 fs_info->extent_root = extent_root;
122 fs_info->chunk_root = chunk_root;
123 fs_info->dev_root = dev_root;
124 fs_info->csum_root = csum_root;
126 fs_info->readonly = 1;
128 extent_io_tree_init(&fs_info->extent_cache);
129 extent_io_tree_init(&fs_info->free_space_cache);
130 extent_io_tree_init(&fs_info->block_group_cache);
131 extent_io_tree_init(&fs_info->pinned_extents);
132 extent_io_tree_init(&fs_info->pending_del);
133 extent_io_tree_init(&fs_info->extent_ins);
134 cache_tree_init(&fs_info->fs_root_cache);
136 cache_tree_init(&fs_info->mapping_tree.cache_tree);
138 mutex_init(&fs_info->fs_mutex);
139 fs_info->fs_devices = fs_devices;
140 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
141 INIT_LIST_HEAD(&fs_info->space_info);
143 __setup_root(4096, 4096, 4096, 4096, tree_root,
144 fs_info, BTRFS_ROOT_TREE_OBJECTID);
146 ret = btrfs_open_devices(fs_devices, O_RDONLY);
150 fs_info->super_bytenr = BTRFS_SUPER_INFO_OFFSET;
151 disk_super = fs_info->super_copy;
152 ret = btrfs_read_dev_super(fs_devices->latest_bdev,
153 disk_super, BTRFS_SUPER_INFO_OFFSET);
155 printk("No valid btrfs found\n");
159 memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
162 features = btrfs_super_incompat_flags(disk_super) &
163 ~BTRFS_FEATURE_INCOMPAT_SUPP;
165 printk("couldn't open because of unsupported "
166 "option features (%Lx).\n", features);
170 features = btrfs_super_incompat_flags(disk_super);
171 if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
172 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
173 btrfs_set_super_incompat_flags(disk_super, features);
176 nodesize = btrfs_super_nodesize(disk_super);
177 leafsize = btrfs_super_leafsize(disk_super);
178 sectorsize = btrfs_super_sectorsize(disk_super);
179 stripesize = btrfs_super_stripesize(disk_super);
180 tree_root->nodesize = nodesize;
181 tree_root->leafsize = leafsize;
182 tree_root->sectorsize = sectorsize;
183 tree_root->stripesize = stripesize;
185 ret = btrfs_read_sys_array(tree_root);
188 blocksize = btrfs_level_size(tree_root,
189 btrfs_super_chunk_root_level(disk_super));
190 generation = btrfs_super_chunk_root_generation(disk_super);
192 __setup_root(nodesize, leafsize, sectorsize, stripesize,
193 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
195 chunk_root->node = read_tree_block(chunk_root,
196 btrfs_super_chunk_root(disk_super),
197 blocksize, generation);
198 if (!chunk_root->node) {
199 printk("Couldn't read chunk root\n");
203 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
204 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
207 if (!(btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)) {
208 ret = btrfs_read_chunk_tree(chunk_root);
213 return fs_info->chunk_root;
215 free_extent_buffer(fs_info->chunk_root->node);
217 close_all_devices(fs_info);
219 extent_io_tree_cleanup(&fs_info->extent_cache);
220 extent_io_tree_cleanup(&fs_info->free_space_cache);
221 extent_io_tree_cleanup(&fs_info->block_group_cache);
222 extent_io_tree_cleanup(&fs_info->pinned_extents);
223 extent_io_tree_cleanup(&fs_info->pending_del);
224 extent_io_tree_cleanup(&fs_info->extent_ins);
235 static int search_iobuf(struct btrfs_root *root, void *iobuf,
236 size_t iobuf_size, off_t offset)
238 u64 gen = btrfs_super_generation(root->fs_info->super_copy);
239 u64 objectid = search_objectid;
240 u32 size = btrfs_super_nodesize(root->fs_info->super_copy);
241 u8 level = root->fs_info->super_copy->root_level;
242 size_t block_off = 0;
244 while (block_off < iobuf_size) {
245 void *block = iobuf + block_off;
246 struct btrfs_header *header = block;
247 u64 h_byte, h_level, h_gen, h_owner;
249 // printf("searching %Lu\n", offset + block_off);
250 h_byte = le64_to_cpu(header->bytenr);
251 h_owner = le64_to_cpu(header->owner);
252 h_level = header->level;
253 h_gen = le64_to_cpu(header->generation);
255 if (h_owner != objectid)
257 if (h_byte != (offset + block_off))
259 if (h_level != level)
261 if (csum_block(block, size)) {
262 fprintf(stderr, "Well block %Lu seems good, "
263 "but the csum doesn't match\n",
268 fprintf(stderr, "Well block %Lu seems great, "
269 "but generation doesn't match, "
270 "have=%Lu, want=%Lu\n", h_byte, h_gen,
274 printf("Found tree root at %Lu\n", h_byte);
283 static int read_physical(struct btrfs_root *root, int fd, u64 offset,
286 char *iobuf = malloc(len);
288 size_t total_read = 0;
292 fprintf(stderr, "No memory\n");
296 while (total_read < len) {
297 done = pread64(fd, iobuf + total_read, len - total_read,
298 bytenr + total_read);
300 fprintf(stderr, "Failed to read: %s\n",
308 ret = search_iobuf(root, iobuf, total_read, offset);
314 static int find_root(struct btrfs_root *root)
316 struct btrfs_multi_bio *multi = NULL;
317 struct btrfs_device *device;
318 u64 metadata_offset = 0, metadata_size = 0;
325 printf("Super think's the tree root is at %Lu, chunk root %Lu\n",
326 btrfs_super_root(root->fs_info->super_copy),
327 btrfs_super_chunk_root(root->fs_info->super_copy));
329 err = btrfs_next_metadata(&root->fs_info->mapping_tree,
330 &metadata_offset, &metadata_size);
334 offset = metadata_offset;
336 u64 map_length = 4096;
340 btrfs_super_total_bytes(root->fs_info->super_copy)) {
341 printf("Went past the fs size, exiting");
344 if (offset >= (metadata_offset + metadata_size)) {
345 err = btrfs_next_metadata(&root->fs_info->mapping_tree,
349 printf("No more metdata to scan, exiting\n");
352 offset = metadata_offset;
354 err = __btrfs_map_block(&root->fs_info->mapping_tree, READ,
355 offset, &map_length, &type,
358 offset += map_length;
362 if (!(type & BTRFS_BLOCK_GROUP_METADATA)) {
363 offset += map_length;
368 device = multi->stripes[0].dev;
370 bytenr = multi->stripes[0].physical;
373 err = read_physical(root, fd, offset, bytenr, map_length);
377 } else if (err < 0) {
381 offset += map_length;
386 int main(int argc, char **argv)
388 struct btrfs_root *root;
393 while ((opt = getopt(argc, argv, "o:")) != -1) {
397 search_objectid = (u64)strtoll(optarg, NULL,
400 fprintf(stderr, "Error parsing "
411 if (optind >= argc) {
416 dev_fd = open(argv[optind], O_RDONLY);
418 fprintf(stderr, "Failed to open device %s\n", argv[optind]);
422 root = open_ctree_broken(dev_fd, argv[optind]);
426 fprintf(stderr, "Open ctree failed\n");
430 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
431 ret = find_root(root);