// SPDX-License-Identifier: GPL-2.0+ #include #include #include #include #include #include "kernel-shared/btrfs_tree.h" #include "common/rbtree-utils.h" #include "disk-io.h" #include "ctree.h" #include "btrfs.h" #include "volumes.h" #include "extent-io.h" #include "crypto/hash.h" /* specified errno for check_tree_block */ #define BTRFS_BAD_BYTENR (-1) #define BTRFS_BAD_FSID (-2) #define BTRFS_BAD_LEVEL (-3) #define BTRFS_BAD_NRITEMS (-4) /* Calculate max possible nritems for a leaf/node */ static u32 max_nritems(u8 level, u32 nodesize) { if (level == 0) return ((nodesize - sizeof(struct btrfs_header)) / sizeof(struct btrfs_item)); return ((nodesize - sizeof(struct btrfs_header)) / sizeof(struct btrfs_key_ptr)); } static int check_tree_block(struct btrfs_fs_info *fs_info, struct extent_buffer *buf) { struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; u32 nodesize = fs_info->nodesize; bool fsid_match = false; int ret = BTRFS_BAD_FSID; if (buf->start != btrfs_header_bytenr(buf)) return BTRFS_BAD_BYTENR; if (btrfs_header_level(buf) >= BTRFS_MAX_LEVEL) return BTRFS_BAD_LEVEL; if (btrfs_header_nritems(buf) > max_nritems(btrfs_header_level(buf), nodesize)) return BTRFS_BAD_NRITEMS; /* Only leaf can be empty */ if (btrfs_header_nritems(buf) == 0 && btrfs_header_level(buf) != 0) return BTRFS_BAD_NRITEMS; while (fs_devices) { /* * Checking the incompat flag is only valid for the current * fs. For seed devices it's forbidden to have their uuid * changed so reading ->fsid in this case is fine */ if (fs_devices == fs_info->fs_devices && btrfs_fs_incompat(fs_info, METADATA_UUID)) fsid_match = !memcmp_extent_buffer(buf, fs_devices->metadata_uuid, btrfs_header_fsid(), BTRFS_FSID_SIZE); else fsid_match = !memcmp_extent_buffer(buf, fs_devices->fsid, btrfs_header_fsid(), BTRFS_FSID_SIZE); if (fsid_match) { ret = 0; break; } fs_devices = fs_devices->seed; } return ret; } static void print_tree_block_error(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, int err) { char fs_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'}; char found_uuid[BTRFS_UUID_UNPARSED_SIZE] = {'\0'}; u8 buf[BTRFS_UUID_SIZE]; if (!err) return; fprintf(stderr, "bad tree block %llu, ", eb->start); switch (err) { case BTRFS_BAD_FSID: read_extent_buffer(eb, buf, btrfs_header_fsid(), BTRFS_UUID_SIZE); uuid_unparse(buf, found_uuid); uuid_unparse(fs_info->fs_devices->metadata_uuid, fs_uuid); fprintf(stderr, "fsid mismatch, want=%s, have=%s\n", fs_uuid, found_uuid); break; case BTRFS_BAD_BYTENR: fprintf(stderr, "bytenr mismatch, want=%llu, have=%llu\n", eb->start, btrfs_header_bytenr(eb)); break; case BTRFS_BAD_LEVEL: fprintf(stderr, "bad level, %u > %d\n", btrfs_header_level(eb), BTRFS_MAX_LEVEL); break; case BTRFS_BAD_NRITEMS: fprintf(stderr, "invalid nr_items: %u\n", btrfs_header_nritems(eb)); break; } } int btrfs_csum_data(u16 csum_type, const u8 *data, u8 *out, size_t len) { memset(out, 0, BTRFS_CSUM_SIZE); switch (csum_type) { case BTRFS_CSUM_TYPE_CRC32: return hash_crc32c(data, len, out); case BTRFS_CSUM_TYPE_XXHASH: return hash_xxhash(data, len, out); case BTRFS_CSUM_TYPE_SHA256: return hash_sha256(data, len, out); case BTRFS_CSUM_TYPE_BLAKE2: return hash_blake2(data, len, out); default: printf("Unknown csum type %d\n", csum_type); return -EINVAL; } } /* * Check if the super is valid: * - nodesize/sectorsize - minimum, maximum, alignment * - tree block starts - alignment * - number of devices - something sane * - sys array size - maximum */ static int btrfs_check_super(struct btrfs_super_block *sb) { u8 result[BTRFS_CSUM_SIZE]; u16 csum_type; int csum_size; u8 *metadata_uuid; if (btrfs_super_magic(sb) != BTRFS_MAGIC) return -EIO; csum_type = btrfs_super_csum_type(sb); if (csum_type >= btrfs_super_num_csums()) { error("unsupported checksum algorithm %u", csum_type); return -EIO; } csum_size = btrfs_super_csum_size(sb); btrfs_csum_data(csum_type, (u8 *)sb + BTRFS_CSUM_SIZE, result, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); if (memcmp(result, sb->csum, csum_size)) { error("superblock checksum mismatch"); return -EIO; } if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) { error("tree_root level too big: %d >= %d", btrfs_super_root_level(sb), BTRFS_MAX_LEVEL); goto error_out; } if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) { error("chunk_root level too big: %d >= %d", btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL); goto error_out; } if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) { error("log_root level too big: %d >= %d", btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL); goto error_out; } if (!IS_ALIGNED(btrfs_super_root(sb), 4096)) { error("tree_root block unaligned: %llu", btrfs_super_root(sb)); goto error_out; } if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096)) { error("chunk_root block unaligned: %llu", btrfs_super_chunk_root(sb)); goto error_out; } if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096)) { error("log_root block unaligned: %llu", btrfs_super_log_root(sb)); goto error_out; } if (btrfs_super_nodesize(sb) < 4096) { error("nodesize too small: %u < 4096", btrfs_super_nodesize(sb)); goto error_out; } if (!IS_ALIGNED(btrfs_super_nodesize(sb), 4096)) { error("nodesize unaligned: %u", btrfs_super_nodesize(sb)); goto error_out; } if (btrfs_super_sectorsize(sb) < 4096) { error("sectorsize too small: %u < 4096", btrfs_super_sectorsize(sb)); goto error_out; } if (!IS_ALIGNED(btrfs_super_sectorsize(sb), 4096)) { error("sectorsize unaligned: %u", btrfs_super_sectorsize(sb)); goto error_out; } if (btrfs_super_total_bytes(sb) == 0) { error("invalid total_bytes 0"); goto error_out; } if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) { error("invalid bytes_used %llu", btrfs_super_bytes_used(sb)); goto error_out; } if ((btrfs_super_stripesize(sb) != 4096) && (btrfs_super_stripesize(sb) != btrfs_super_sectorsize(sb))) { error("invalid stripesize %u", btrfs_super_stripesize(sb)); goto error_out; } if (btrfs_super_incompat_flags(sb) & BTRFS_FEATURE_INCOMPAT_METADATA_UUID) metadata_uuid = sb->metadata_uuid; else metadata_uuid = sb->fsid; if (memcmp(metadata_uuid, sb->dev_item.fsid, BTRFS_FSID_SIZE) != 0) { char fsid[BTRFS_UUID_UNPARSED_SIZE]; char dev_fsid[BTRFS_UUID_UNPARSED_SIZE]; uuid_unparse(sb->metadata_uuid, fsid); uuid_unparse(sb->dev_item.fsid, dev_fsid); error("dev_item UUID does not match fsid: %s != %s", dev_fsid, fsid); goto error_out; } /* * Hint to catch really bogus numbers, bitflips or so */ if (btrfs_super_num_devices(sb) > (1UL << 31)) { error("suspicious number of devices: %llu", btrfs_super_num_devices(sb)); } if (btrfs_super_num_devices(sb) == 0) { error("number of devices is 0"); goto error_out; } /* * Obvious sys_chunk_array corruptions, it must hold at least one key * and one chunk */ if (btrfs_super_sys_array_size(sb) > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) { error("system chunk array too big %u > %u", btrfs_super_sys_array_size(sb), BTRFS_SYSTEM_CHUNK_ARRAY_SIZE); goto error_out; } if (btrfs_super_sys_array_size(sb) < sizeof(struct btrfs_disk_key) + sizeof(struct btrfs_chunk)) { error("system chunk array too small %u < %zu", btrfs_super_sys_array_size(sb), sizeof(struct btrfs_disk_key) + sizeof(struct btrfs_chunk)); goto error_out; } return 0; error_out: error("superblock checksum matches but it has invalid members"); return -EIO; } /* * btrfs_read_dev_super - read a valid primary superblock from a block device * @desc,@part: file descriptor of the device * @sb: buffer where the superblock is going to be read in * * Unlike the btrfs-progs/kernel version, here we ony care about the first * super block, thus it's much simpler. */ int btrfs_read_dev_super(struct blk_desc *desc, struct disk_partition *part, struct btrfs_super_block *sb) { ALLOC_CACHE_ALIGN_BUFFER(char, tmp, BTRFS_SUPER_INFO_SIZE); struct btrfs_super_block *buf = (struct btrfs_super_block *)tmp; int ret; ret = __btrfs_devread(desc, part, tmp, BTRFS_SUPER_INFO_SIZE, BTRFS_SUPER_INFO_OFFSET); if (ret < BTRFS_SUPER_INFO_SIZE) return -EIO; if (btrfs_super_bytenr(buf) != BTRFS_SUPER_INFO_OFFSET) return -EIO; if (btrfs_check_super(buf)) return -EIO; memcpy(sb, buf, BTRFS_SUPER_INFO_SIZE); return 0; } static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size, int verify, int silent, u16 csum_type) { u8 result[BTRFS_CSUM_SIZE]; u32 len; len = buf->len - BTRFS_CSUM_SIZE; btrfs_csum_data(csum_type, (u8 *)buf->data + BTRFS_CSUM_SIZE, result, len); if (verify) { if (memcmp_extent_buffer(buf, result, 0, csum_size)) { /* FIXME: format */ if (!silent) printk("checksum verify failed on %llu found %08X wanted %08X\n", (unsigned long long)buf->start, result[0], buf->data[0]); return 1; } } else { write_extent_buffer(buf, result, 0, csum_size); } return 0; } int csum_tree_block_size(struct extent_buffer *buf, u16 csum_size, int verify, u16 csum_type) { return __csum_tree_block_size(buf, csum_size, verify, 0, csum_type); } static int csum_tree_block(struct btrfs_fs_info *fs_info, struct extent_buffer *buf, int verify) { u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); u16 csum_type = btrfs_super_csum_type(fs_info->super_copy); return csum_tree_block_size(buf, csum_size, verify, csum_type); } struct extent_buffer *btrfs_find_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr, u32 blocksize) { return find_extent_buffer(&fs_info->extent_cache, bytenr, blocksize); } struct extent_buffer* btrfs_find_create_tree_block( struct btrfs_fs_info *fs_info, u64 bytenr) { return alloc_extent_buffer(fs_info, bytenr, fs_info->nodesize); } static int verify_parent_transid(struct extent_io_tree *io_tree, struct extent_buffer *eb, u64 parent_transid, int ignore) { int ret; if (!parent_transid || btrfs_header_generation(eb) == parent_transid) return 0; if (extent_buffer_uptodate(eb) && btrfs_header_generation(eb) == parent_transid) { ret = 0; goto out; } printk("parent transid verify failed on %llu wanted %llu found %llu\n", (unsigned long long)eb->start, (unsigned long long)parent_transid, (unsigned long long)btrfs_header_generation(eb)); if (ignore) { eb->flags |= EXTENT_BAD_TRANSID; printk("Ignoring transid failure\n"); return 0; } ret = 1; out: clear_extent_buffer_uptodate(eb); return ret; } int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror) { unsigned long offset = 0; struct btrfs_multi_bio *multi = NULL; struct btrfs_device *device; int ret = 0; u64 read_len; unsigned long bytes_left = eb->len; while (bytes_left) { read_len = bytes_left; device = NULL; ret = btrfs_map_block(info, READ, eb->start + offset, &read_len, &multi, mirror, NULL); if (ret) { printk("Couldn't map the block %Lu\n", eb->start + offset); kfree(multi); return -EIO; } device = multi->stripes[0].dev; if (!device->desc || !device->part) { kfree(multi); return -EIO; } if (read_len > bytes_left) read_len = bytes_left; ret = read_extent_from_disk(device->desc, device->part, multi->stripes[0].physical, eb, offset, read_len); kfree(multi); multi = NULL; if (ret) return -EIO; offset += read_len; bytes_left -= read_len; } return 0; } struct extent_buffer* read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr, u64 parent_transid) { int ret; struct extent_buffer *eb; u64 best_transid = 0; u32 sectorsize = fs_info->sectorsize; int mirror_num = 1; int good_mirror = 0; int candidate_mirror = 0; int num_copies; int ignore = 0; /* * Don't even try to create tree block for unaligned tree block * bytenr. * Such unaligned tree block will free overlapping extent buffer, * causing use-after-free bugs for fuzzed images. */ if (bytenr < sectorsize || !IS_ALIGNED(bytenr, sectorsize)) { error("tree block bytenr %llu is not aligned to sectorsize %u", bytenr, sectorsize); return ERR_PTR(-EIO); } eb = btrfs_find_create_tree_block(fs_info, bytenr); if (!eb) return ERR_PTR(-ENOMEM); if (btrfs_buffer_uptodate(eb, parent_transid)) return eb; num_copies = btrfs_num_copies(fs_info, eb->start, eb->len); while (1) { ret = read_whole_eb(fs_info, eb, mirror_num); if (ret == 0 && csum_tree_block(fs_info, eb, 1) == 0 && check_tree_block(fs_info, eb) == 0 && verify_parent_transid(&fs_info->extent_cache, eb, parent_transid, ignore) == 0) { /* * check_tree_block() is less strict to allow btrfs * check to get raw eb with bad key order and fix it. * But we still need to try to get a good copy if * possible, or bad key order can go into tools like * btrfs ins dump-tree. */ if (btrfs_header_level(eb)) ret = btrfs_check_node(fs_info, NULL, eb); else ret = btrfs_check_leaf(fs_info, NULL, eb); if (!ret || candidate_mirror == mirror_num) { btrfs_set_buffer_uptodate(eb); return eb; } if (candidate_mirror <= 0) candidate_mirror = mirror_num; } if (ignore) { if (candidate_mirror > 0) { mirror_num = candidate_mirror; continue; } if (check_tree_block(fs_info, eb)) print_tree_block_error(fs_info, eb, check_tree_block(fs_info, eb)); else fprintf(stderr, "Csum didn't match\n"); ret = -EIO; break; } if (num_copies == 1) { ignore = 1; continue; } if (btrfs_header_generation(eb) > best_transid) { best_transid = btrfs_header_generation(eb); good_mirror = mirror_num; } mirror_num++; if (mirror_num > num_copies) { if (candidate_mirror > 0) mirror_num = candidate_mirror; else mirror_num = good_mirror; ignore = 1; continue; } } /* * We failed to read this tree block, it be should deleted right now * to avoid stale cache populate the cache. */ free_extent_buffer(eb); return ERR_PTR(ret); } int read_extent_data(struct btrfs_fs_info *fs_info, char *data, u64 logical, u64 *len, int mirror) { u64 orig_len = *len; u64 cur = logical; struct btrfs_multi_bio *multi = NULL; struct btrfs_device *device; int ret = 0; while (cur < logical + orig_len) { u64 cur_len = logical + orig_len - cur; ret = btrfs_map_block(fs_info, READ, cur, &cur_len, &multi, mirror, NULL); if (ret) { error("Couldn't map the block %llu", cur); goto err; } device = multi->stripes[0].dev; if (!device->desc || !device->part) { error("devid %llu is missing", device->devid); ret = -EIO; goto err; } ret = __btrfs_devread(device->desc, device->part, data + (cur - logical), cur_len, multi->stripes[0].physical); if (ret != cur_len) { error("read failed on devid %llu physical %llu", device->devid, multi->stripes[0].physical); ret = -EIO; goto err; } cur += cur_len; ret = 0; } err: kfree(multi); return ret; } void btrfs_setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info, u64 objectid) { root->node = NULL; root->track_dirty = 0; root->fs_info = fs_info; root->objectid = objectid; root->last_trans = 0; root->last_inode_alloc = 0; memset(&root->root_key, 0, sizeof(root->root_key)); memset(&root->root_item, 0, sizeof(root->root_item)); root->root_key.objectid = objectid; } static int find_and_setup_root(struct btrfs_root *tree_root, struct btrfs_fs_info *fs_info, u64 objectid, struct btrfs_root *root) { int ret; u64 generation; btrfs_setup_root(root, fs_info, objectid); ret = btrfs_find_last_root(tree_root, objectid, &root->root_item, &root->root_key); if (ret) return ret; generation = btrfs_root_generation(&root->root_item); root->node = read_tree_block(fs_info, btrfs_root_bytenr(&root->root_item), generation); if (!extent_buffer_uptodate(root->node)) return -EIO; return 0; } int btrfs_free_fs_root(struct btrfs_root *root) { if (root->node) free_extent_buffer(root->node); kfree(root); return 0; } static void __free_fs_root(struct rb_node *node) { struct btrfs_root *root; root = container_of(node, struct btrfs_root, rb_node); btrfs_free_fs_root(root); } FREE_RB_BASED_TREE(fs_roots, __free_fs_root); struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info, struct btrfs_key *location) { struct btrfs_root *root; struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_path *path; struct extent_buffer *l; u64 generation; int ret = 0; root = calloc(1, sizeof(*root)); if (!root) return ERR_PTR(-ENOMEM); if (location->offset == (u64)-1) { ret = find_and_setup_root(tree_root, fs_info, location->objectid, root); if (ret) { free(root); return ERR_PTR(ret); } goto insert; } btrfs_setup_root(root, fs_info, location->objectid); path = btrfs_alloc_path(); if (!path) { free(root); return ERR_PTR(-ENOMEM); } ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0); if (ret != 0) { if (ret > 0) ret = -ENOENT; goto out; } l = path->nodes[0]; read_extent_buffer(l, &root->root_item, btrfs_item_ptr_offset(l, path->slots[0]), sizeof(root->root_item)); memcpy(&root->root_key, location, sizeof(*location)); /* If this root is already an orphan, no need to read */ if (btrfs_root_refs(&root->root_item) == 0) { ret = -ENOENT; goto out; } ret = 0; out: btrfs_free_path(path); if (ret) { free(root); return ERR_PTR(ret); } generation = btrfs_root_generation(&root->root_item); root->node = read_tree_block(fs_info, btrfs_root_bytenr(&root->root_item), generation); if (!extent_buffer_uptodate(root->node)) { free(root); return ERR_PTR(-EIO); } insert: root->ref_cows = 1; return root; } static int btrfs_fs_roots_compare_objectids(struct rb_node *node, void *data) { u64 objectid = *((u64 *)data); struct btrfs_root *root; root = rb_entry(node, struct btrfs_root, rb_node); if (objectid > root->objectid) return 1; else if (objectid < root->objectid) return -1; else return 0; } int btrfs_fs_roots_compare_roots(struct rb_node *node1, struct rb_node *node2) { struct btrfs_root *root; root = rb_entry(node2, struct btrfs_root, rb_node); return btrfs_fs_roots_compare_objectids(node1, (void *)&root->objectid); } struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_key *location) { struct btrfs_root *root; struct rb_node *node; int ret; u64 objectid = location->objectid; if (location->objectid == BTRFS_ROOT_TREE_OBJECTID) return fs_info->tree_root; if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID) return fs_info->chunk_root; if (location->objectid == BTRFS_CSUM_TREE_OBJECTID) return fs_info->csum_root; BUG_ON(location->objectid == BTRFS_TREE_RELOC_OBJECTID); node = rb_search(&fs_info->fs_root_tree, (void *)&objectid, btrfs_fs_roots_compare_objectids, NULL); if (node) return container_of(node, struct btrfs_root, rb_node); root = btrfs_read_fs_root_no_cache(fs_info, location); if (IS_ERR(root)) return root; ret = rb_insert(&fs_info->fs_root_tree, &root->rb_node, btrfs_fs_roots_compare_roots); BUG_ON(ret); return root; } void btrfs_free_fs_info(struct btrfs_fs_info *fs_info) { free(fs_info->tree_root); free(fs_info->chunk_root); free(fs_info->csum_root); free(fs_info->super_copy); free(fs_info); } struct btrfs_fs_info *btrfs_new_fs_info(void) { struct btrfs_fs_info *fs_info; fs_info = calloc(1, sizeof(struct btrfs_fs_info)); if (!fs_info) return NULL; fs_info->tree_root = calloc(1, sizeof(struct btrfs_root)); fs_info->chunk_root = calloc(1, sizeof(struct btrfs_root)); fs_info->csum_root = calloc(1, sizeof(struct btrfs_root)); fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE); if (!fs_info->tree_root || !fs_info->chunk_root || !fs_info->csum_root || !fs_info->super_copy) goto free_all; extent_io_tree_init(&fs_info->extent_cache); fs_info->fs_root_tree = RB_ROOT; cache_tree_init(&fs_info->mapping_tree.cache_tree); return fs_info; free_all: btrfs_free_fs_info(fs_info); return NULL; } static int setup_root_or_create_block(struct btrfs_fs_info *fs_info, struct btrfs_root *info_root, u64 objectid, char *str) { struct btrfs_root *root = fs_info->tree_root; int ret; ret = find_and_setup_root(root, fs_info, objectid, info_root); if (ret) { error("could not setup %s tree", str); return -EIO; } return 0; } static int get_default_subvolume(struct btrfs_fs_info *fs_info, struct btrfs_key *key_ret) { struct btrfs_root *root = fs_info->tree_root; struct btrfs_dir_item *dir_item; struct btrfs_path path; int ret = 0; btrfs_init_path(&path); dir_item = btrfs_lookup_dir_item(NULL, root, &path, BTRFS_ROOT_TREE_DIR_OBJECTID, "default", 7, 0); if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); goto out; } btrfs_dir_item_key_to_cpu(path.nodes[0], dir_item, key_ret); out: btrfs_release_path(&path); return ret; } int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info) { struct btrfs_super_block *sb = fs_info->super_copy; struct btrfs_root *root; struct btrfs_key key; u64 root_tree_bytenr; u64 generation; int ret; root = fs_info->tree_root; btrfs_setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID); generation = btrfs_super_generation(sb); root_tree_bytenr = btrfs_super_root(sb); root->node = read_tree_block(fs_info, root_tree_bytenr, generation); if (!extent_buffer_uptodate(root->node)) { fprintf(stderr, "Couldn't read tree root\n"); return -EIO; } ret = setup_root_or_create_block(fs_info, fs_info->csum_root, BTRFS_CSUM_TREE_OBJECTID, "csum"); if (ret) return ret; fs_info->csum_root->track_dirty = 1; fs_info->last_trans_committed = generation; ret = get_default_subvolume(fs_info, &key); if (ret) { /* * The default dir item isn't there. Linux kernel behaviour is * to silently use the top-level subvolume in this case. */ key.objectid = BTRFS_FS_TREE_OBJECTID; key.type = BTRFS_ROOT_ITEM_KEY; key.offset = (u64)-1; } fs_info->fs_root = btrfs_read_fs_root(fs_info, &key); if (IS_ERR(fs_info->fs_root)) return -EIO; return 0; } void btrfs_release_all_roots(struct btrfs_fs_info *fs_info) { if (fs_info->csum_root) free_extent_buffer(fs_info->csum_root->node); if (fs_info->tree_root) free_extent_buffer(fs_info->tree_root->node); if (fs_info->chunk_root) free_extent_buffer(fs_info->chunk_root->node); } static void free_map_lookup(struct cache_extent *ce) { struct map_lookup *map; map = container_of(ce, struct map_lookup, ce); kfree(map); } FREE_EXTENT_CACHE_BASED_TREE(mapping_cache, free_map_lookup); void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info) { free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree); extent_io_tree_cleanup(&fs_info->extent_cache); } static int btrfs_scan_fs_devices(struct blk_desc *desc, struct disk_partition *part, struct btrfs_fs_devices **fs_devices) { u64 total_devs; int ret; if (round_up(BTRFS_SUPER_INFO_SIZE + BTRFS_SUPER_INFO_OFFSET, desc->blksz) > (part->size << desc->log2blksz)) { log_debug("superblock end %u is larger than device size " LBAFU, BTRFS_SUPER_INFO_SIZE + BTRFS_SUPER_INFO_OFFSET, part->size << desc->log2blksz); return -EINVAL; } ret = btrfs_scan_one_device(desc, part, fs_devices, &total_devs); if (ret) { /* * Avoid showing this when probing for a possible Btrfs * * fprintf(stderr, "No valid Btrfs found\n"); */ return ret; } return 0; } int btrfs_check_fs_compatibility(struct btrfs_super_block *sb) { u64 features; features = btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP; if (features) { printk("couldn't open because of unsupported " "option features (%llx).\n", (unsigned long long)features); return -ENOTSUPP; } features = btrfs_super_incompat_flags(sb); if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) { features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF; btrfs_set_super_incompat_flags(sb, features); } return 0; } static int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info) { struct btrfs_super_block *sb = fs_info->super_copy; u64 chunk_root_bytenr; u64 generation; int ret; btrfs_setup_root(fs_info->chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID); ret = btrfs_read_sys_array(fs_info); if (ret) return ret; generation = btrfs_super_chunk_root_generation(sb); chunk_root_bytenr = btrfs_super_chunk_root(sb); fs_info->chunk_root->node = read_tree_block(fs_info, chunk_root_bytenr, generation); if (!extent_buffer_uptodate(fs_info->chunk_root->node)) { error("cannot read chunk root"); return -EIO; } ret = btrfs_read_chunk_tree(fs_info); if (ret) { fprintf(stderr, "Couldn't read chunk tree\n"); return ret; } return 0; } struct btrfs_fs_info *open_ctree_fs_info(struct blk_desc *desc, struct disk_partition *part) { struct btrfs_fs_info *fs_info; struct btrfs_super_block *disk_super; struct btrfs_fs_devices *fs_devices = NULL; struct extent_buffer *eb; int ret; fs_info = btrfs_new_fs_info(); if (!fs_info) { fprintf(stderr, "Failed to allocate memory for fs_info\n"); return NULL; } ret = btrfs_scan_fs_devices(desc, part, &fs_devices); if (ret) goto out; fs_info->fs_devices = fs_devices; ret = btrfs_open_devices(fs_devices); if (ret) goto out; disk_super = fs_info->super_copy; ret = btrfs_read_dev_super(desc, part, disk_super); if (ret) { debug("No valid btrfs found\n"); goto out_devices; } if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID) { fprintf(stderr, "ERROR: Filesystem UUID change in progress\n"); goto out_devices; } ASSERT(!memcmp(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE)); if (btrfs_fs_incompat(fs_info, METADATA_UUID)) ASSERT(!memcmp(disk_super->metadata_uuid, fs_devices->metadata_uuid, BTRFS_FSID_SIZE)); fs_info->sectorsize = btrfs_super_sectorsize(disk_super); fs_info->nodesize = btrfs_super_nodesize(disk_super); fs_info->stripesize = btrfs_super_stripesize(disk_super); ret = btrfs_check_fs_compatibility(fs_info->super_copy); if (ret) goto out_devices; ret = btrfs_setup_chunk_tree_and_device_map(fs_info); if (ret) goto out_chunk; /* Chunk tree root is unable to read, return directly */ if (!fs_info->chunk_root) return fs_info; eb = fs_info->chunk_root->node; read_extent_buffer(eb, fs_info->chunk_tree_uuid, btrfs_header_chunk_tree_uuid(eb), BTRFS_UUID_SIZE); ret = btrfs_setup_all_roots(fs_info); if (ret) goto out_chunk; return fs_info; out_chunk: btrfs_release_all_roots(fs_info); btrfs_cleanup_all_caches(fs_info); out_devices: btrfs_close_devices(fs_devices); out: btrfs_free_fs_info(fs_info); return NULL; } int close_ctree_fs_info(struct btrfs_fs_info *fs_info) { int ret; free_fs_roots_tree(&fs_info->fs_root_tree); btrfs_release_all_roots(fs_info); ret = btrfs_close_devices(fs_info->fs_devices); btrfs_cleanup_all_caches(fs_info); btrfs_free_fs_info(fs_info); return ret; } int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid) { int ret; ret = extent_buffer_uptodate(buf); if (!ret) return ret; ret = verify_parent_transid(&buf->fs_info->extent_cache, buf, parent_transid, 1); return !ret; } int btrfs_set_buffer_uptodate(struct extent_buffer *eb) { return set_extent_buffer_uptodate(eb); }