/* * Copyright (C) 2007 Oracle. 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 "kerncompat.h" #include #include #include #include #include #include #include #include #include #include #include "kernel-lib/bitops.h" #include "kernel-lib/list.h" #include "kernel-lib/rbtree.h" #include "kernel-lib/rbtree_types.h" #include "kernel-shared/accessors.h" #include "kernel-shared/extent-io-tree.h" #include "kernel-shared/extent_io.h" #include "kernel-shared/locking.h" #include "kernel-shared/messages.h" #include "kernel-shared/uapi/btrfs_tree.h" #include "kernel-shared/ctree.h" #include "kernel-shared/disk-io.h" #include "kernel-shared/volumes.h" #include "kernel-shared/transaction.h" #include "kernel-shared/tree-checker.h" #include "kernel-shared/zoned.h" #include "crypto/hash.h" #include "common/defs.h" #include "common/extent-cache.h" #include "common/messages.h" #include "common/utils.h" #include "common/rbtree-utils.h" #include "common/device-scan.h" #include "common/device-utils.h" struct btrfs_fs_devices; struct btrfs_key; struct btrfs_super_block; struct btrfs_trans_handle; struct extent_buffer; struct rb_node; /* 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 (fs_info->ignore_fsid_mismatch || 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(struct btrfs_fs_info *fs_info, 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_blake2b(data, len, out); default: fprintf(stderr, "ERROR: unknown csum type: %d\n", csum_type); ASSERT(0); } return -1; } 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(buf->fs_info, csum_type, (u8 *)buf->data + BTRFS_CSUM_SIZE, result, len); if (verify) { if (buf->fs_info && buf->fs_info->skip_csum_check) { /* printf("skip csum check for block %llu\n", buf->start); */ } else if (memcmp_extent_buffer(buf, result, 0, csum_size)) { if (!silent) { char found[BTRFS_CSUM_STRING_LEN]; char wanted[BTRFS_CSUM_STRING_LEN]; btrfs_format_csum(csum_type, result, found); btrfs_format_csum(csum_type, (u8 *)buf->data, wanted); printk( "checksum verify failed on %llu wanted %s found %s\n", (unsigned long long)buf->start, wanted, found); } 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); } int verify_tree_block_csum_silent(struct extent_buffer *buf, u16 csum_size, u16 csum_type) { return __csum_tree_block_size(buf, csum_size, 1, 1, csum_type); } static int csum_tree_block(struct btrfs_fs_info *fs_info, struct extent_buffer *buf, int verify) { u16 csum_size = fs_info->csum_size; u16 csum_type = fs_info->csum_type; if (verify && fs_info->suppress_check_block_errors) return verify_tree_block_csum_silent(buf, csum_size, csum_type); 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, bytenr); } 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); } void readahead_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr, u64 parent_transid) { struct extent_buffer *eb; u64 length; struct btrfs_multi_bio *multi = NULL; struct btrfs_device *device; eb = btrfs_find_tree_block(fs_info, bytenr, fs_info->nodesize); if (!(eb && btrfs_buffer_uptodate(eb, parent_transid, 0)) && !btrfs_map_block(fs_info, READ, bytenr, &length, &multi, 0, NULL)) { device = multi->stripes[0].dev; device->total_ios++; readahead(device->fd, multi->stripes[0].physical, fs_info->nodesize); } free_extent_buffer(eb); kfree(multi); } static int verify_parent_transid(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_BUFFER_BAD_TRANSID; printk("Ignoring transid failure\n"); return 0; } ret = 1; out: clear_extent_buffer_uptodate(eb); return ret; } static int read_on_restore(struct extent_buffer *eb) { struct btrfs_fs_info *fs_info = eb->fs_info; struct btrfs_device *device; int ret; /* * For on_restoring mode, there should be only one device, and logical * address is mapped 1:1 to device physical offset. */ list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) { if (device->devid == 1) break; } device->total_ios++; ret = btrfs_pread(device->fd, eb->data, eb->len, eb->start, eb->fs_info->zoned); if (ret != eb->len) ret = -EIO; else ret = 0; return ret; } int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror) { unsigned long offset = 0; int ret = 0; unsigned long bytes_left = eb->len; while (bytes_left) { u64 read_len = bytes_left; if (info->on_restoring) return read_on_restore(eb); ret = read_data_from_disk(info, eb->data + offset, eb->start + offset, &read_len, mirror); if (ret < 0) return ret; offset += read_len; bytes_left -= read_len; } return 0; } int btrfs_read_extent_buffer(struct extent_buffer *eb, struct btrfs_tree_parent_check *check) { struct btrfs_fs_info *fs_info = eb->fs_info; int ret; u64 best_transid = 0; int mirror_num = 1; int good_mirror = 0; int candidate_mirror = 0; int num_copies; int ignore = 0; 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(eb, check->transid, ignore) == 0) { if (eb->flags & EXTENT_BUFFER_BAD_TRANSID && list_empty(&eb->recow)) { list_add_tail(&eb->recow, &fs_info->recow_ebs); eb->refs++; } /* * 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(eb); else ret = __btrfs_check_leaf(eb); if (!ret || candidate_mirror == mirror_num) { btrfs_set_buffer_uptodate(eb); return 0; } 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)) { if (!fs_info->suppress_check_block_errors) print_tree_block_error(fs_info, eb, check_tree_block(fs_info, eb)); } else { if (!fs_info->suppress_check_block_errors) fprintf(stderr, "Csum didn't match\n"); } ret = -EIO; break; } if (num_copies == 1 && fs_info->allow_transid_mismatch) { 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 (!fs_info->allow_transid_mismatch) { ret = -EIO; break; } if (candidate_mirror > 0) mirror_num = candidate_mirror; else mirror_num = good_mirror; ignore = 1; continue; } } return ret; } struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr, struct btrfs_tree_parent_check *check) { int ret; struct extent_buffer *eb; u32 sectorsize = fs_info->sectorsize; /* * 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, check->transid, 0)) return eb; ret = btrfs_read_extent_buffer(eb, check); if (ret) { /* * We failed to read this tree block, it be should deleted right * now to avoid stale cache populate the cache. */ free_extent_buffer_nocache(eb); return ERR_PTR(ret); } return eb; } int write_tree_block(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, struct extent_buffer *eb) { if (check_tree_block(fs_info, eb)) { print_tree_block_error(fs_info, eb, check_tree_block(fs_info, eb)); BUG(); } if (trans && !btrfs_buffer_uptodate(eb, trans->transid, 0)) BUG(); btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN); csum_tree_block(fs_info, eb, 0); return write_data_to_disk(fs_info, eb->data, eb->start, eb->len); } void btrfs_setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info, u64 objectid) { root->node = NULL; root->commit_root = NULL; root->state = 0; root->fs_info = fs_info; root->objectid = objectid; root->last_trans = 0; root->last_inode_alloc = 0; INIT_LIST_HEAD(&root->dirty_list); INIT_LIST_HEAD(&root->unaligned_extent_recs); 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 read_root_node(struct btrfs_fs_info *fs_info, struct btrfs_root *root, u64 bytenr, u64 gen, int level) { struct btrfs_tree_parent_check check = { .owner_root = btrfs_root_id(root), .transid = gen, .level = level, }; root->node = read_tree_block(fs_info, bytenr, &check); if (!extent_buffer_uptodate(root->node)) goto err; if (btrfs_header_level(root->node) != level) { error("root [%llu %llu] level %d does not match %d\n", root->root_key.objectid, root->root_key.offset, btrfs_header_level(root->node), level); goto err; } return 0; err: free_extent_buffer(root->node); root->node = NULL; return -EIO; } int btrfs_find_and_setup_root(struct btrfs_root *tree_root, struct btrfs_fs_info *fs_info, u64 objectid, struct btrfs_root *root) { int ret; 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; return read_root_node(fs_info, root, btrfs_root_bytenr(&root->root_item), btrfs_root_generation(&root->root_item), btrfs_root_level(&root->root_item)); } static int find_and_setup_log_root(struct btrfs_root *tree_root, struct btrfs_fs_info *fs_info, struct btrfs_super_block *disk_super) { u64 blocknr = btrfs_super_log_root(disk_super); struct btrfs_root *log_root = kmalloc(sizeof(struct btrfs_root), GFP_KERNEL); int ret; if (!log_root) return -ENOMEM; if (blocknr == 0) { kfree(log_root); return 0; } btrfs_setup_root(log_root, fs_info, BTRFS_TREE_LOG_OBJECTID); ret = read_root_node(fs_info, log_root, blocknr, btrfs_super_generation(disk_super) + 1, btrfs_super_log_root_level(disk_super)); if (ret) { kfree(log_root); fs_info->log_root_tree = NULL; return ret; } fs_info->log_root_tree = log_root; return 0; } int btrfs_free_fs_root(struct btrfs_root *root) { if (root->node) free_extent_buffer(root->node); if (root->commit_root) free_extent_buffer(root->commit_root); 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 = btrfs_find_and_setup_root(tree_root, fs_info, location->objectid, root); if (ret) { kfree(root); return ERR_PTR(ret); } goto insert; } btrfs_setup_root(root, fs_info, location->objectid); path = btrfs_alloc_path(); if (!path) { kfree(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)); ret = 0; out: btrfs_free_path(path); if (ret) { kfree(root); return ERR_PTR(ret); } generation = btrfs_root_generation(&root->root_item); ret = read_root_node(fs_info, root, btrfs_root_bytenr(&root->root_item), generation, btrfs_root_level(&root->root_item)); if (ret) { kfree(root); return ERR_PTR(-EIO); } insert: if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state); if (is_fstree(root->root_key.objectid)) set_bit(BTRFS_ROOT_SHAREABLE, &root->state); return root; } static int btrfs_global_roots_compare_keys(const struct rb_node *node, const void *data) { const struct btrfs_key *key = (struct btrfs_key *)data; const struct btrfs_root *root; root = rb_entry(node, struct btrfs_root, rb_node); return btrfs_comp_cpu_keys(key, &root->root_key); } static int btrfs_global_roots_compare(const struct rb_node *node1, const struct rb_node *node2) { const struct btrfs_root *root = rb_entry(node2, struct btrfs_root, rb_node); return btrfs_global_roots_compare_keys(node1, &root->root_key); } static int btrfs_fs_roots_compare_objectids(const struct rb_node *node, const void *data) { u64 objectid = *((const u64 *)data); const 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(const struct rb_node *node1, const struct rb_node *node2) { const struct btrfs_root *root; root = rb_entry(node2, struct btrfs_root, rb_node); return btrfs_fs_roots_compare_objectids(node1, &root->objectid); } int btrfs_global_root_insert(struct btrfs_fs_info *fs_info, struct btrfs_root *root) { return rb_insert(&fs_info->global_roots_tree, &root->rb_node, btrfs_global_roots_compare); } struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info, struct btrfs_key *key) { struct rb_node *node; /* * Some callers use the key->offset = (u64)-1 convention for looking up * roots, so set this to 0 if we ended up here from that. */ if (key->offset == (u64)-1) key->offset = 0; node = rb_search(&fs_info->global_roots_tree, (void *)key, btrfs_global_roots_compare_keys, NULL); if (node) return rb_entry(node, struct btrfs_root, rb_node); return NULL; } u64 btrfs_global_root_id(struct btrfs_fs_info *fs_info, u64 bytenr) { struct btrfs_block_group *block_group; u64 ret = 0; if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) return ret; /* * We use this because we won't have this many global roots, and -1 is * special, so we need something that'll not be found if we have any * errors from here on. */ ret = BTRFS_LAST_FREE_OBJECTID; block_group = btrfs_lookup_first_block_group(fs_info, bytenr); if (block_group) ret = block_group->global_root_id; return ret; } struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr) { struct btrfs_key key = { .objectid = BTRFS_CSUM_TREE_OBJECTID, .type = BTRFS_ROOT_ITEM_KEY, .offset = btrfs_global_root_id(fs_info, bytenr), }; return btrfs_global_root(fs_info, &key); } struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr) { struct btrfs_key key = { .objectid = BTRFS_EXTENT_TREE_OBJECTID, .type = BTRFS_ROOT_ITEM_KEY, .offset = btrfs_global_root_id(fs_info, bytenr), }; return btrfs_global_root(fs_info, &key); } 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_EXTENT_TREE_OBJECTID) return btrfs_global_root(fs_info, location); if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID) return fs_info->chunk_root; if (location->objectid == BTRFS_DEV_TREE_OBJECTID) return fs_info->dev_root; if (location->objectid == BTRFS_CSUM_TREE_OBJECTID) return btrfs_global_root(fs_info, location); if (location->objectid == BTRFS_UUID_TREE_OBJECTID) return fs_info->uuid_root ? fs_info->uuid_root : ERR_PTR(-ENOENT); if (location->objectid == BTRFS_QUOTA_TREE_OBJECTID) return fs_info->quota_enabled ? fs_info->quota_root : ERR_PTR(-ENOENT); if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID) { root = btrfs_global_root(fs_info, location); return root ? root : ERR_PTR(-ENOENT); } if (location->objectid == BTRFS_BLOCK_GROUP_TREE_OBJECTID) return fs_info->block_group_root ? fs_info->block_group_root : ERR_PTR(-ENOENT); if (location->objectid == BTRFS_RAID_STRIPE_TREE_OBJECTID) return fs_info->stripe_root ? fs_info->stripe_root : ERR_PTR(-ENOENT); 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; } static void __free_global_root(struct rb_node *node) { struct btrfs_root *root; root = rb_entry(node, struct btrfs_root, rb_node); kfree(root); } FREE_RB_BASED_TREE(global_roots, __free_global_root); void btrfs_free_fs_info(struct btrfs_fs_info *fs_info) { if (fs_info->quota_root) kfree(fs_info->quota_root); if (fs_info->stripe_root) kfree(fs_info->stripe_root); free_global_roots_tree(&fs_info->global_roots_tree); kfree(fs_info->tree_root); kfree(fs_info->chunk_root); kfree(fs_info->dev_root); kfree(fs_info->uuid_root); kfree(fs_info->block_group_root); kfree(fs_info->super_copy); kfree(fs_info->log_root_tree); kfree(fs_info); } struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr) { 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->dev_root = calloc(1, sizeof(struct btrfs_root)); fs_info->quota_root = calloc(1, sizeof(struct btrfs_root)); fs_info->uuid_root = calloc(1, sizeof(struct btrfs_root)); fs_info->stripe_root = calloc(1, sizeof(struct btrfs_root)); fs_info->block_group_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->dev_root || !fs_info->quota_root || !fs_info->uuid_root || !fs_info->block_group_root || !fs_info->super_copy || !fs_info->stripe_root) goto free_all; extent_buffer_init_cache(fs_info); extent_io_tree_init(fs_info, &fs_info->dirty_buffers, 0); extent_io_tree_init(fs_info, &fs_info->free_space_cache, 0); extent_io_tree_init(fs_info, &fs_info->pinned_extents, 0); extent_io_tree_init(fs_info, &fs_info->extent_ins, 0); fs_info->block_group_cache_tree = RB_ROOT; fs_info->excluded_extents = NULL; fs_info->fs_root_tree = RB_ROOT; cache_tree_init(&fs_info->mapping_tree.cache_tree); INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots); INIT_LIST_HEAD(&fs_info->space_info); INIT_LIST_HEAD(&fs_info->recow_ebs); spin_lock_init(&fs_info->trans_lock); init_rwsem(&fs_info->commit_root_sem); if (!writable) fs_info->readonly = 1; fs_info->super_bytenr = sb_bytenr; fs_info->data_alloc_profile = (u64)-1; fs_info->metadata_alloc_profile = (u64)-1; fs_info->system_alloc_profile = fs_info->metadata_alloc_profile; fs_info->nr_global_roots = 1; fs_info->initial_fd = -1; return fs_info; free_all: btrfs_free_fs_info(fs_info); return NULL; } int btrfs_check_fs_compatibility(struct btrfs_super_block *sb, unsigned int flags) { 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 -ENOTSUP; } 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); } features = btrfs_super_compat_ro_flags(sb); if (flags & OPEN_CTREE_WRITES) { if (flags & OPEN_CTREE_INVALIDATE_FST) { /* Clear the FREE_SPACE_TREE_VALID bit on disk... */ features &= ~BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID; btrfs_set_super_compat_ro_flags(sb, features); /* ... and ignore the free space tree bit. */ features &= ~BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE; } if (features & ~BTRFS_FEATURE_COMPAT_RO_SUPP) { printk("couldn't open RDWR because of unsupported " "option features (0x%llx)\n", (unsigned long long)features); return -ENOTSUP; } } return 0; } static int find_best_backup_root(struct btrfs_super_block *super) { struct btrfs_root_backup *backup; u64 orig_gen = btrfs_super_generation(super); u64 gen = 0; int best_index = 0; int i; for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) { backup = super->super_roots + i; if (btrfs_backup_tree_root_gen(backup) != orig_gen && btrfs_backup_tree_root_gen(backup) > gen) { best_index = i; gen = btrfs_backup_tree_root_gen(backup); } } return best_index; } static int read_root_or_create_block(struct btrfs_fs_info *fs_info, struct btrfs_root *root, u64 bytenr, u64 gen, int level, unsigned flags, char *str) { int ret; ret = read_root_node(fs_info, root, bytenr, gen, level); if (ret) { if (!(flags & OPEN_CTREE_PARTIAL)) { error("could not setup %s tree", str); return -EIO; } warning("could not setup %s tree, skipping it", str); /* * Need a blank node here just so we don't screw up in the * million of places that assume a root has a valid ->node */ root->node = btrfs_find_create_tree_block(fs_info, 0); if (!root->node) return -ENOMEM; clear_extent_buffer_uptodate(root->node); } return 0; } static inline bool maybe_load_block_groups(struct btrfs_fs_info *fs_info, u64 flags) { struct btrfs_root *root = btrfs_block_group_root(fs_info); if (flags & OPEN_CTREE_NO_BLOCK_GROUPS) return false; if (root && extent_buffer_uptodate(root->node)) return true; return false; } static int load_global_roots_objectid(struct btrfs_fs_info *fs_info, struct btrfs_path *path, u64 objectid, unsigned flags, char *str) { struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_root *root; int ret; int found = 0; struct btrfs_key key = { .objectid = objectid, .type = BTRFS_ROOT_ITEM_KEY, .offset = 0, }; ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); if (ret < 0) { error("could not find %s tree", str); return ret; } ret = 0; while (1) { if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { ret = btrfs_next_leaf(tree_root, path); if (ret) { if (ret > 0) ret = 0; break; } } btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.objectid != objectid) break; if (key.offset >= fs_info->nr_global_roots) { warning("global root with too large of an offset [%llu %llu]", key.objectid, key.offset); ret = -EINVAL; break; } root = calloc(1, sizeof(*root)); if (!root) { ret = -ENOMEM; break; } btrfs_setup_root(root, fs_info, objectid); read_extent_buffer(path->nodes[0], &root->root_item, btrfs_item_ptr_offset(path->nodes[0], path->slots[0]), sizeof(root->root_item)); memcpy(&root->root_key, &key, sizeof(key)); ret = read_root_or_create_block(fs_info, root, btrfs_root_bytenr(&root->root_item), btrfs_root_generation(&root->root_item), btrfs_root_level(&root->root_item), flags, str); if (ret) { kfree(root); break; } set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state); ret = btrfs_global_root_insert(fs_info, root); if (ret) { free_extent_buffer(root->node); kfree(root); break; } found++; path->slots[0]++; } btrfs_release_path(path); /* * We didn't find all of our roots, create empty ones if we have PARTIAL * set. */ if (!ret && found < fs_info->nr_global_roots) { int i; if (!(flags & OPEN_CTREE_PARTIAL)) { error("could not setup %s tree", str); return -EIO; } warning("could not setup %s tree, skipping it", str); for (i = found; i < fs_info->nr_global_roots; i++) { root = calloc(1, sizeof(*root)); if (!root) { ret = -ENOMEM; break; } btrfs_setup_root(root, fs_info, objectid); root->root_key.objectid = objectid; root->root_key.type = BTRFS_ROOT_ITEM_KEY; root->root_key.offset = i; set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state); root->node = btrfs_find_create_tree_block(fs_info, 0); if (!root->node) { kfree(root); ret = -ENOMEM; break; } clear_extent_buffer_uptodate(root->node); ret = btrfs_global_root_insert(fs_info, root); if (ret) { free_extent_buffer(root->node); kfree(root); break; } } } return ret; } static int load_global_roots(struct btrfs_fs_info *fs_info, unsigned flags) { struct btrfs_path *path; int ret = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; ret = load_global_roots_objectid(fs_info, path, BTRFS_EXTENT_TREE_OBJECTID, flags, "extent"); if (ret) goto out; ret = load_global_roots_objectid(fs_info, path, BTRFS_CSUM_TREE_OBJECTID, flags, "csum"); if (ret) goto out; if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) goto out; ret = load_global_roots_objectid(fs_info, path, BTRFS_FREE_SPACE_TREE_OBJECTID, flags, "free space"); out: btrfs_free_path(path); return ret; } static int load_important_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr, unsigned flags) { struct btrfs_super_block *sb = fs_info->super_copy; struct btrfs_root_backup *backup = NULL; struct btrfs_root *root; u64 bytenr, gen; int level; int index = -1; int ret; if (flags & OPEN_CTREE_BACKUP_ROOT) { index = find_best_backup_root(sb); if (index >= BTRFS_NUM_BACKUP_ROOTS) { fprintf(stderr, "Invalid backup root number\n"); return -EIO; } backup = sb->super_roots + index; } if (!btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE) && !(btrfs_super_flags(fs_info->super_copy) & BTRFS_SUPER_FLAG_CHANGING_BG_TREE)) { kfree(fs_info->block_group_root); fs_info->block_group_root = NULL; goto tree_root; } root = fs_info->block_group_root; btrfs_setup_root(root, fs_info, BTRFS_BLOCK_GROUP_TREE_OBJECTID); tree_root: if (backup) { bytenr = btrfs_backup_tree_root(backup); gen = btrfs_backup_tree_root_gen(backup); level = btrfs_backup_tree_root_level(backup); } else { if (root_tree_bytenr) bytenr = root_tree_bytenr; else bytenr = btrfs_super_root(sb); gen = btrfs_super_generation(sb); level = btrfs_super_root_level(sb); } fs_info->generation = gen; fs_info->last_trans_committed = gen; root = fs_info->tree_root; btrfs_setup_root(root, fs_info, BTRFS_ROOT_TREE_OBJECTID); ret = read_root_node(fs_info, root, bytenr, gen, level); if (ret) { fprintf(stderr, "Couldn't read tree root\n"); return -EIO; } return 0; } int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr, unsigned flags) { struct btrfs_super_block *sb = fs_info->super_copy; struct btrfs_root *root = fs_info->tree_root; struct btrfs_key key; int ret; ret = load_important_roots(fs_info, root_tree_bytenr, flags); if (ret) return ret; ret = load_global_roots(fs_info, flags); if (ret) return ret; if (btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE) || btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_CHANGING_BG_TREE) { ret = btrfs_find_and_setup_root(root, fs_info, BTRFS_BLOCK_GROUP_TREE_OBJECTID, fs_info->block_group_root); if (ret) { error("couldn't load block group tree"); return -EIO; } set_bit(BTRFS_ROOT_TRACK_DIRTY, &fs_info->block_group_root->state); } ret = btrfs_find_and_setup_root(root, fs_info, BTRFS_DEV_TREE_OBJECTID, fs_info->dev_root); if (ret) { printk("Couldn't setup device tree\n"); return -EIO; } set_bit(BTRFS_ROOT_TRACK_DIRTY, &fs_info->dev_root->state); ret = btrfs_find_and_setup_root(root, fs_info, BTRFS_UUID_TREE_OBJECTID, fs_info->uuid_root); if (ret) { kfree(fs_info->uuid_root); fs_info->uuid_root = NULL; } else { set_bit(BTRFS_ROOT_TRACK_DIRTY, &fs_info->uuid_root->state); } ret = btrfs_find_and_setup_root(root, fs_info, BTRFS_QUOTA_TREE_OBJECTID, fs_info->quota_root); if (ret) { kfree(fs_info->quota_root); fs_info->quota_root = NULL; } else { fs_info->quota_enabled = 1; } ret = find_and_setup_log_root(root, fs_info, sb); if (ret) { printk("Couldn't setup log root tree\n"); if (!(flags & OPEN_CTREE_PARTIAL)) return -EIO; } if (btrfs_fs_incompat(fs_info, RAID_STRIPE_TREE)) { ret = btrfs_find_and_setup_root(root, fs_info, BTRFS_RAID_STRIPE_TREE_OBJECTID, fs_info->stripe_root); if (ret) { kfree(fs_info->stripe_root); fs_info->stripe_root = NULL; } else { set_bit(BTRFS_ROOT_TRACK_DIRTY, &fs_info->stripe_root->state); } } if (maybe_load_block_groups(fs_info, flags)) { ret = btrfs_read_block_groups(fs_info); /* * If we don't find any blockgroups (ENOENT) we're either * restoring or creating the filesystem, where it's expected, * anything else is error */ if (ret < 0 && ret != -ENOENT) { errno = -ret; error("failed to read block groups: %m"); return ret; } } 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; } static void release_global_roots(struct btrfs_fs_info *fs_info) { struct btrfs_root *root; struct rb_node *n; for (n = rb_first(&fs_info->global_roots_tree); n; n = rb_next(n)) { root = rb_entry(n, struct btrfs_root, rb_node); if (root->node) free_extent_buffer(root->node); if (root->commit_root) free_extent_buffer(root->commit_root); root->node = NULL; root->commit_root = NULL; } } void btrfs_release_all_roots(struct btrfs_fs_info *fs_info) { release_global_roots(fs_info); if (fs_info->block_group_root) free_extent_buffer(fs_info->block_group_root->node); if (fs_info->quota_root) free_extent_buffer(fs_info->quota_root->node); if (fs_info->dev_root) free_extent_buffer(fs_info->dev_root->node); if (fs_info->tree_root) free_extent_buffer(fs_info->tree_root->node); if (fs_info->log_root_tree) free_extent_buffer(fs_info->log_root_tree->node); if (fs_info->chunk_root) free_extent_buffer(fs_info->chunk_root->node); if (fs_info->uuid_root) free_extent_buffer(fs_info->uuid_root->node); if (fs_info->stripe_root) free_extent_buffer(fs_info->stripe_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) { while (!list_empty(&fs_info->recow_ebs)) { struct extent_buffer *eb; eb = list_first_entry(&fs_info->recow_ebs, struct extent_buffer, recow); list_del_init(&eb->recow); free_extent_buffer(eb); } free_mapping_cache_tree(&fs_info->mapping_tree.cache_tree); extent_io_tree_release(&fs_info->dirty_buffers); extent_buffer_free_cache(fs_info); extent_io_tree_release(&fs_info->free_space_cache); extent_io_tree_release(&fs_info->pinned_extents); extent_io_tree_release(&fs_info->extent_ins); } int btrfs_scan_fs_devices(int fd, const char *path, struct btrfs_fs_devices **fs_devices, u64 sb_bytenr, unsigned sbflags, int skip_devices) { u64 total_devs; u64 dev_size; off_t seek_ret; int ret; if (!sb_bytenr) sb_bytenr = BTRFS_SUPER_INFO_OFFSET; seek_ret = lseek(fd, 0, SEEK_END); if (seek_ret < 0) return -errno; dev_size = seek_ret; lseek(fd, 0, SEEK_SET); if (sb_bytenr > dev_size) { error("superblock bytenr %llu is larger than device size %llu", (unsigned long long)sb_bytenr, (unsigned long long)dev_size); return -EINVAL; } ret = btrfs_scan_one_device(fd, path, fs_devices, &total_devs, sb_bytenr, sbflags); if (ret) { fprintf(stderr, "No valid Btrfs found on %s\n", path); return ret; } if (!skip_devices && total_devs != 1) { ret = btrfs_scan_devices(0); if (ret) return ret; } return 0; } int btrfs_setup_chunk_tree_and_device_map(struct btrfs_fs_info *fs_info, u64 chunk_root_bytenr) { struct btrfs_super_block *sb = fs_info->super_copy; 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); if (chunk_root_bytenr && !IS_ALIGNED(chunk_root_bytenr, fs_info->sectorsize)) { warning("chunk_root_bytenr %llu is unaligned to %u, ignore it", chunk_root_bytenr, fs_info->sectorsize); chunk_root_bytenr = 0; } if (!chunk_root_bytenr) chunk_root_bytenr = btrfs_super_chunk_root(sb); else generation = 0; ret = read_root_node(fs_info, fs_info->chunk_root, chunk_root_bytenr, generation, btrfs_super_chunk_root_level(sb)); if (ret) { if (fs_info->ignore_chunk_tree_error) { warning("cannot read chunk root, continue anyway"); fs_info->chunk_root = NULL; return 0; } else { error("cannot read chunk root"); return -EIO; } } if (!(btrfs_super_flags(sb) & BTRFS_SUPER_FLAG_METADUMP)) { ret = btrfs_read_chunk_tree(fs_info); if (ret) { fprintf(stderr, "Couldn't read chunk tree\n"); return ret; } } return 0; } static struct btrfs_fs_info *__open_ctree_fd(int fp, struct open_ctree_args *oca) { 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; int oflags; unsigned sbflags = SBREAD_DEFAULT; unsigned flags = oca->flags; u64 sb_bytenr = oca->sb_bytenr; if (sb_bytenr == 0) sb_bytenr = BTRFS_SUPER_INFO_OFFSET; /* try to drop all the caches */ if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED)) fprintf(stderr, "Warning, could not drop caches\n"); fs_info = btrfs_new_fs_info(flags & OPEN_CTREE_WRITES, sb_bytenr); if (!fs_info) { error_msg(ERROR_MSG_MEMORY, "fs_info"); return NULL; } if (flags & OPEN_CTREE_RESTORE) fs_info->on_restoring = 1; if (flags & OPEN_CTREE_SUPPRESS_CHECK_BLOCK_ERRORS) fs_info->suppress_check_block_errors = 1; if (flags & OPEN_CTREE_IGNORE_FSID_MISMATCH) fs_info->ignore_fsid_mismatch = 1; if (flags & OPEN_CTREE_SKIP_CSUM_CHECK) fs_info->skip_csum_check = 1; if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR) fs_info->ignore_chunk_tree_error = 1; if (flags & OPEN_CTREE_HIDE_NAMES) fs_info->hide_names = 1; if (flags & OPEN_CTREE_ALLOW_TRANSID_MISMATCH) fs_info->allow_transid_mismatch = 1; if (flags & OPEN_CTREE_SKIP_LEAF_ITEM_CHECKS) fs_info->skip_leaf_item_checks = 1; if ((flags & OPEN_CTREE_RECOVER_SUPER) && (flags & OPEN_CTREE_TEMPORARY_SUPER)) { fprintf(stderr, "cannot open a filesystem with temporary super block for recovery"); goto out; } if (flags & OPEN_CTREE_TEMPORARY_SUPER) sbflags = SBREAD_TEMPORARY; if (flags & OPEN_CTREE_IGNORE_FSID_MISMATCH) sbflags |= SBREAD_IGNORE_FSID_MISMATCH; ret = btrfs_scan_fs_devices(fp, oca->filename, &fs_devices, sb_bytenr, sbflags, (flags & OPEN_CTREE_NO_DEVICES)); if (ret) goto out; fs_info->fs_devices = fs_devices; if (flags & OPEN_CTREE_WRITES) oflags = O_RDWR; else oflags = O_RDONLY; if (flags & OPEN_CTREE_EXCLUSIVE) oflags |= O_EXCL; ret = btrfs_open_devices(fs_info, fs_devices, oflags); if (ret) goto out; disk_super = fs_info->super_copy; if (flags & OPEN_CTREE_RECOVER_SUPER) ret = btrfs_read_dev_super(fs_devices->latest_bdev, disk_super, sb_bytenr, SBREAD_RECOVER); else if (flags & OPEN_CTREE_USE_LATEST_BDEV) ret = btrfs_read_dev_super(fs_devices->latest_bdev, disk_super, sb_bytenr, sbflags); else ret = btrfs_read_dev_super(fp, disk_super, sb_bytenr, sbflags); if (ret) { printk("No valid btrfs found\n"); goto out_devices; } if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID && !fs_info->ignore_fsid_mismatch) { fprintf(stderr, "ERROR: Filesystem UUID change in progress\n"); goto out_devices; } /* CHECK: ignore_csum_mismatch */ 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); fs_info->csum_type = btrfs_super_csum_type(disk_super); fs_info->csum_size = btrfs_super_csum_size(disk_super); fs_info->leaf_data_size = __BTRFS_LEAF_DATA_SIZE(fs_info->nodesize); ret = btrfs_check_fs_compatibility(fs_info->super_copy, flags); if (ret) goto out_devices; if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) fs_info->nr_global_roots = btrfs_super_nr_global_roots(fs_info->super_copy); /* * fs_info->zone_size (and zoned) are not known before reading the * chunk tree, so it's 0 at this point. But, fs_info->zoned == 0 * will cause btrfs_pread() not to use an aligned bounce buffer, * causing EINVAL when the file is opened with O_DIRECT. Temporarily * set zoned = 1 in that case. */ if (fcntl(fp, F_GETFL) & O_DIRECT) fs_info->zoned = 1; ret = btrfs_setup_chunk_tree_and_device_map(fs_info, oca->chunk_tree_bytenr); if (ret) goto out_chunk; fs_info->zoned = 0; /* Chunk tree root is unable to read, return directly */ if (!fs_info->chunk_root) return fs_info; /* * Get zone type information of zoned block devices. This will also * handle emulation of a zoned filesystem if a regular device has the * zoned incompat feature flag set. */ ret = btrfs_get_dev_zone_info_all_devices(fs_info); if (ret) { error("zoned: failed to read device zone info: %d", ret); goto out_chunk; } ret = btrfs_check_zoned_mode(fs_info); if (ret) { error("zoned: failed to initialize zoned mode: %d", ret); goto out_chunk; } 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, oca->root_tree_bytenr, flags); if (ret && !(flags & __OPEN_CTREE_RETURN_CHUNK_ROOT) && !fs_info->ignore_chunk_tree_error) 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; } struct btrfs_fs_info *open_ctree_fs_info(struct open_ctree_args *oca) { int fp; int ret; struct btrfs_fs_info *info; int oflags = O_RDWR; struct stat st; ret = stat(oca->filename, &st); if (ret < 0) { error("cannot stat '%s': %m", oca->filename); return NULL; } if (!(((st.st_mode & S_IFMT) == S_IFREG) || ((st.st_mode & S_IFMT) == S_IFBLK))) { error("not a regular file or block device: %s", oca->filename); return NULL; } if (!(oca->flags & OPEN_CTREE_WRITES)) oflags = O_RDONLY; if ((oflags & O_RDWR) && zoned_model(oca->filename) == ZONED_HOST_MANAGED) oflags |= O_DIRECT; fp = open(oca->filename, oflags); if (fp < 0) { error("cannot open '%s': %m", oca->filename); return NULL; } info = __open_ctree_fd(fp, oca); if (info) info->initial_fd = fp; else close(fp); return info; } struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr, unsigned flags) { struct btrfs_fs_info *info; struct open_ctree_args oca = { 0 }; /* This flags may not return fs_info with any valid root */ BUG_ON(flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR); oca.filename = filename; oca.sb_bytenr = sb_bytenr; oca.flags = flags; info = open_ctree_fs_info(&oca); if (!info) return NULL; if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT) return info->chunk_root; return info->fs_root; } struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr, unsigned flags) { struct btrfs_fs_info *info; struct open_ctree_args oca = { 0 }; /* This flags may not return fs_info with any valid root */ if (flags & OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR) { error("invalid open_ctree flags: 0x%llx", (unsigned long long)flags); return NULL; } oca.filename = path; oca.sb_bytenr = sb_bytenr; oca.flags = flags; info = __open_ctree_fd(fp, &oca); if (!info) return NULL; if (flags & __OPEN_CTREE_RETURN_CHUNK_ROOT) return info->chunk_root; return info->fs_root; } /* * Check if the super is valid: * - nodesize/sectorsize - minimum, maximum, alignment * - tree block starts - alignment * - number of devices - something sane * - sys array size - maximum */ int btrfs_check_super(struct btrfs_super_block *sb, unsigned sbflags) { u8 result[BTRFS_CSUM_SIZE]; u16 csum_type; int csum_size; u8 *metadata_uuid; if (btrfs_super_magic(sb) != BTRFS_MAGIC) { if (btrfs_super_magic(sb) == BTRFS_MAGIC_TEMPORARY) { if (!(sbflags & SBREAD_TEMPORARY)) { error("superblock magic doesn't match"); return -EIO; } } } csum_type = btrfs_super_csum_type(sb); if (csum_type >= btrfs_get_num_csums()) { error("unsupported checksum algorithm %u", csum_type); return -EIO; } csum_size = btrfs_super_csum_size(sb); btrfs_csum_data(NULL, 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); if (sbflags & SBREAD_IGNORE_FSID_MISMATCH) { warning("ignored: dev_item fsid mismatch: %s != %s", dev_fsid, fsid); } else { 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)) { warning("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 superblock from a block device * @fd: file descriptor of the device * @sb: buffer where the superblock is going to be read in * @sb_bytenr: offset of the particular superblock copy we want * @sbflags: flags controlling how the superblock is read * * This function is used by various btrfs commands to obtain a valid superblock. * * It's mode of operation is controlled by the @sb_bytenr and @sbdflags * parameters. If SBREAD_RECOVER flag is set and @sb_bytenr is * BTRFS_SUPER_INFO_OFFSET then the function reads all 3 superblock copies and * returns the newest one. If SBREAD_RECOVER is not set then only a single * copy is read, which one is decided by @sb_bytenr. If @sb_bytenr != * BTRFS_SUPER_INFO_OFFSET then the @sbflags is effectively ignored and only a * single copy is read. */ int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr, unsigned sbflags) { u8 fsid[BTRFS_FSID_SIZE]; u8 metadata_uuid[BTRFS_FSID_SIZE]; int fsid_is_initialized = 0; struct btrfs_super_block buf; int i; int ret; int max_super = sbflags & SBREAD_RECOVER ? BTRFS_SUPER_MIRROR_MAX : 1; u64 transid = 0; bool metadata_uuid_set = false; u64 bytenr; if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) { ret = sbread(fd, &buf, sb_bytenr); /* real error */ if (ret < 0) return -errno; /* Not large enough sb, return -ENOENT instead of normal -EIO */ if (ret < BTRFS_SUPER_INFO_SIZE) return -ENOENT; if (btrfs_super_bytenr(&buf) != sb_bytenr) return -EIO; ret = btrfs_check_super(&buf, sbflags); if (ret < 0) return ret; memcpy(sb, &buf, BTRFS_SUPER_INFO_SIZE); return 0; } /* * we would like to check all the supers, but that would make * a btrfs mount succeed after a mkfs from a different FS. * So, we need to add a special mount option to scan for * later supers, using BTRFS_SUPER_MIRROR_MAX instead */ for (i = 0; i < max_super; i++) { bytenr = btrfs_sb_offset(i); ret = sbread(fd, &buf, bytenr); if (ret < BTRFS_SUPER_INFO_SIZE) break; if (btrfs_super_bytenr(&buf) != bytenr ) continue; /* if magic is NULL, the device was removed */ if (btrfs_super_magic(&buf) == 0 && i == 0) break; if (btrfs_check_super(&buf, sbflags)) continue; if (!fsid_is_initialized) { if (btrfs_super_incompat_flags(&buf) & BTRFS_FEATURE_INCOMPAT_METADATA_UUID) { metadata_uuid_set = true; memcpy(metadata_uuid, buf.metadata_uuid, sizeof(metadata_uuid)); } memcpy(fsid, buf.fsid, sizeof(fsid)); fsid_is_initialized = 1; } else if (memcmp(fsid, buf.fsid, sizeof(fsid)) || (metadata_uuid_set && memcmp(metadata_uuid, buf.metadata_uuid, sizeof(metadata_uuid)))) { /* * the superblocks (the original one and * its backups) contain data of different * filesystems -> the super cannot be trusted */ continue; } if (btrfs_super_generation(&buf) > transid) { memcpy(sb, &buf, BTRFS_SUPER_INFO_SIZE); transid = btrfs_super_generation(&buf); } } return transid > 0 ? 0 : -1; } static bool check_sb_location(struct btrfs_device *device, u64 bytenr) { if (!device->zone_info) return bytenr + BTRFS_SUPER_INFO_SIZE <= device->total_bytes; return btrfs_sb_zone_exists(device, bytenr); } static int write_dev_supers(struct btrfs_fs_info *fs_info, struct btrfs_super_block *sb, struct btrfs_device *device) { u64 bytenr; u8 result[BTRFS_CSUM_SIZE]; int i, ret; u16 csum_type = btrfs_super_csum_type(sb); /* * We need to write super block after all metadata written. * This is the equivalent of kernel pre-flush for FUA. */ ret = fsync(device->fd); if (ret < 0) { error( "failed to write super block for devid %llu: flush error: %m", device->devid); return -errno; } if (fs_info->super_bytenr != BTRFS_SUPER_INFO_OFFSET) { btrfs_set_super_bytenr(sb, fs_info->super_bytenr); btrfs_csum_data(fs_info, csum_type, (u8 *)sb + BTRFS_CSUM_SIZE, result, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); memcpy(&sb->csum[0], result, BTRFS_CSUM_SIZE); /* * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is * zero filled, we can use it directly */ ret = sbwrite(device->fd, fs_info->super_copy, fs_info->super_bytenr); if (ret != BTRFS_SUPER_INFO_SIZE) { errno = EIO; error( "failed to write super block for devid %llu: write error: %m", device->devid); return -EIO; } ret = fsync(device->fd); if (ret < 0) { error( "failed to write super block for devid %llu: flush error: %m", device->devid); return -errno; } return 0; } for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { bytenr = btrfs_sb_offset(i); if (!check_sb_location(device, bytenr)) break; btrfs_set_super_bytenr(sb, bytenr); btrfs_csum_data(fs_info, csum_type, (u8 *)sb + BTRFS_CSUM_SIZE, result, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); memcpy(&sb->csum[0], result, BTRFS_CSUM_SIZE); /* * super_copy is BTRFS_SUPER_INFO_SIZE bytes and is * zero filled, we can use it directly */ ret = sbwrite(device->fd, fs_info->super_copy, bytenr); if (ret != BTRFS_SUPER_INFO_SIZE) { errno = EIO; error( "failed to write super block for devid %llu: write error: %m", device->devid); return -errno; } /* * Flush after the primary sb write, this is the equivalent of * kernel post-flush for FUA write. */ if (i == 0) { ret = fsync(device->fd); if (ret < 0) { error( "failed to write super block for devid %llu: flush error: %m", device->devid); return -errno; } } } return 0; } /* * copy all the root pointers into the super backup array. * this will bump the backup pointer by one when it is * done */ static void backup_super_roots(struct btrfs_fs_info *info) { struct btrfs_root_backup *root_backup; int next_backup; int last_backup; last_backup = find_best_backup_root(info->super_copy); next_backup = (last_backup + 1) % BTRFS_NUM_BACKUP_ROOTS; /* just overwrite the last backup if we're at the same generation */ root_backup = info->super_copy->super_roots + last_backup; if (btrfs_backup_tree_root_gen(root_backup) == btrfs_header_generation(info->tree_root->node)) next_backup = last_backup; root_backup = info->super_copy->super_roots + next_backup; /* * make sure all of our padding and empty slots get zero filled * regardless of which ones we use today */ memset(root_backup, 0, sizeof(*root_backup)); btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start); btrfs_set_backup_tree_root_gen(root_backup, btrfs_header_generation(info->tree_root->node)); btrfs_set_backup_tree_root_level(root_backup, btrfs_header_level(info->tree_root->node)); btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start); btrfs_set_backup_chunk_root_gen(root_backup, btrfs_header_generation(info->chunk_root->node)); btrfs_set_backup_chunk_root_level(root_backup, btrfs_header_level(info->chunk_root->node)); /* * we might commit during log recovery, which happens before we set * the fs_root. Make sure it is valid before we fill it in. */ if (info->fs_root && info->fs_root->node) { btrfs_set_backup_fs_root(root_backup, info->fs_root->node->start); btrfs_set_backup_fs_root_gen(root_backup, btrfs_header_generation(info->fs_root->node)); btrfs_set_backup_fs_root_level(root_backup, btrfs_header_level(info->fs_root->node)); } btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start); btrfs_set_backup_dev_root_gen(root_backup, btrfs_header_generation(info->dev_root->node)); btrfs_set_backup_dev_root_level(root_backup, btrfs_header_level(info->dev_root->node)); btrfs_set_backup_total_bytes(root_backup, btrfs_super_total_bytes(info->super_copy)); btrfs_set_backup_bytes_used(root_backup, btrfs_super_bytes_used(info->super_copy)); btrfs_set_backup_num_devices(root_backup, btrfs_super_num_devices(info->super_copy)); if (!btrfs_fs_incompat(info, EXTENT_TREE_V2)) { struct btrfs_root *extent_root = btrfs_extent_root(info, 0); struct btrfs_root *csum_root = btrfs_csum_root(info, 0); btrfs_set_backup_csum_root(root_backup, csum_root->node->start); btrfs_set_backup_csum_root_gen(root_backup, btrfs_header_generation(csum_root->node)); btrfs_set_backup_csum_root_level(root_backup, btrfs_header_level(csum_root->node)); btrfs_set_backup_extent_root(root_backup, extent_root->node->start); btrfs_set_backup_extent_root_gen(root_backup, btrfs_header_generation(extent_root->node)); btrfs_set_backup_extent_root_level(root_backup, btrfs_header_level(extent_root->node)); } } int write_all_supers(struct btrfs_fs_info *fs_info) { struct list_head *head = &fs_info->fs_devices->devices; struct btrfs_device *dev; struct btrfs_super_block *sb; struct btrfs_dev_item *dev_item; int ret; u64 flags; backup_super_roots(fs_info); sb = fs_info->super_copy; dev_item = &sb->dev_item; list_for_each_entry(dev, head, dev_list) { if (!dev->writeable) continue; btrfs_set_stack_device_generation(dev_item, 0); btrfs_set_stack_device_type(dev_item, dev->type); btrfs_set_stack_device_id(dev_item, dev->devid); btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes); btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used); btrfs_set_stack_device_io_align(dev_item, dev->io_align); btrfs_set_stack_device_io_width(dev_item, dev->io_width); btrfs_set_stack_device_sector_size(dev_item, dev->sector_size); memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE); memcpy(dev_item->fsid, fs_info->fs_devices->metadata_uuid, BTRFS_FSID_SIZE); flags = btrfs_super_flags(sb); btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN); ret = write_dev_supers(fs_info, sb, dev); if (ret < 0) return ret; } return 0; } int write_ctree_super(struct btrfs_trans_handle *trans) { int ret; struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_root *chunk_root = fs_info->chunk_root; if (fs_info->readonly) return 0; btrfs_set_super_generation(fs_info->super_copy, trans->transid); btrfs_set_super_root(fs_info->super_copy, tree_root->node->start); btrfs_set_super_root_level(fs_info->super_copy, btrfs_header_level(tree_root->node)); btrfs_set_super_chunk_root(fs_info->super_copy, chunk_root->node->start); btrfs_set_super_chunk_root_level(fs_info->super_copy, btrfs_header_level(chunk_root->node)); btrfs_set_super_chunk_root_generation(fs_info->super_copy, btrfs_header_generation(chunk_root->node)); ret = write_all_supers(fs_info); if (ret) fprintf(stderr, "failed to write new super block err %d\n", ret); return ret; } int close_ctree_fs_info(struct btrfs_fs_info *fs_info) { int ret; int err = 0; struct btrfs_trans_handle *trans; struct btrfs_root *root = fs_info->tree_root; if (fs_info->last_trans_committed != fs_info->generation) { BUG_ON(!root); trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { err = PTR_ERR(trans); goto skip_commit; } btrfs_commit_transaction(trans, root); trans = btrfs_start_transaction(root, 1); BUG_ON(IS_ERR(trans)); ret = commit_tree_roots(trans, fs_info); BUG_ON(ret); ret = __commit_transaction(trans, root); BUG_ON(ret); ret = write_ctree_super(trans); kfree(trans); if (ret) { err = ret; goto skip_commit; } } if (fs_info->finalize_on_close) { ret = btrfs_wipe_temporary_sb(fs_info->fs_devices); if (ret) { error("zoned: failed to wipe temporary super blocks: %m"); goto skip_commit; } btrfs_set_super_magic(fs_info->super_copy, BTRFS_MAGIC); root->fs_info->finalize_on_close = 0; ret = write_all_supers(fs_info); if (ret) fprintf(stderr, "failed to write new super block err %d\n", ret); } skip_commit: btrfs_free_block_groups(fs_info); free_fs_roots_tree(&fs_info->fs_root_tree); btrfs_release_all_roots(fs_info); ret = btrfs_close_devices(fs_info->fs_devices); if (fs_info->initial_fd >= 0) close(fs_info->initial_fd); btrfs_cleanup_all_caches(fs_info); btrfs_free_fs_info(fs_info); if (!err) err = ret; return err; } void btrfs_mark_buffer_dirty(struct extent_buffer *eb) { set_extent_buffer_dirty(eb); } int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid, int atomic) { int ret; ret = extent_buffer_uptodate(buf); if (!ret) return ret; ret = verify_parent_transid(buf, parent_transid, buf->fs_info->allow_transid_mismatch); return !ret; } int btrfs_set_buffer_uptodate(struct extent_buffer *eb) { return set_extent_buffer_uptodate(eb); } static bool is_global_root(struct btrfs_root *root) { if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID || root->root_key.objectid == BTRFS_CSUM_TREE_OBJECTID || root->root_key.objectid == BTRFS_FREE_SPACE_TREE_OBJECTID) return true; return false; } int btrfs_delete_and_free_root(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *tree_root = fs_info->tree_root; int ret; ret = btrfs_del_root(trans, tree_root, &root->root_key); if (ret) return ret; list_del(&root->dirty_list); ret = btrfs_clear_buffer_dirty(trans, root->node); if (ret) return ret; ret = btrfs_free_tree_block(trans, btrfs_root_id(root), root->node, 0, 1); if (ret) return ret; if (is_global_root(root)) rb_erase(&root->rb_node, &fs_info->global_roots_tree); free_extent_buffer(root->node); free_extent_buffer(root->commit_root); kfree(root); return 0; } struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, struct btrfs_key *key) { struct extent_buffer *leaf; struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_root *root; int ret = 0; root = kzalloc(sizeof(*root), GFP_KERNEL); if (!root) return ERR_PTR(-ENOMEM); btrfs_setup_root(root, fs_info, key->objectid); memcpy(&root->root_key, key, sizeof(struct btrfs_key)); leaf = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, NULL, 0, 0, 0, BTRFS_NESTING_NORMAL); if (IS_ERR(leaf)) { ret = PTR_ERR(leaf); leaf = NULL; goto fail; } memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header)); btrfs_set_header_bytenr(leaf, leaf->start); btrfs_set_header_generation(leaf, trans->transid); btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV); btrfs_set_header_owner(leaf, root->root_key.objectid); root->node = leaf; write_extent_buffer_fsid(leaf, fs_info->fs_devices->metadata_uuid); write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid); btrfs_mark_buffer_dirty(leaf); extent_buffer_get(root->node); root->commit_root = root->node; set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state); root->root_item.flags = 0; root->root_item.byte_limit = 0; btrfs_set_root_bytenr(&root->root_item, leaf->start); btrfs_set_root_generation(&root->root_item, trans->transid); btrfs_set_root_level(&root->root_item, 0); btrfs_set_root_refs(&root->root_item, 1); btrfs_set_root_used(&root->root_item, leaf->len); btrfs_set_root_last_snapshot(&root->root_item, 0); btrfs_set_root_dirid(&root->root_item, 0); memset(root->root_item.uuid, 0, BTRFS_UUID_SIZE); root->root_item.drop_level = 0; ret = btrfs_insert_root(trans, tree_root, &root->root_key, &root->root_item); if (ret) goto fail; return root; fail: if (leaf) free_extent_buffer(leaf); kfree(root); return ERR_PTR(ret); }