diff options
| -rw-r--r-- | cmds-check.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/cmds-check.c b/cmds-check.c index e9f9d683..595b663a 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -2517,6 +2517,148 @@ static void account_bytes(struct btrfs_root *root, struct btrfs_path *path, } } +/* + * This function only handles BACKREF_MISSING, + * If corresponding extent item exists, increase the ref, else insert an extent + * item and backref. + * + * Returns error bits after repair. + */ +static int repair_tree_block_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *node, + struct node_refs *nrefs, int level, int err) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_root *extent_root = fs_info->extent_root; + struct btrfs_path path; + struct btrfs_extent_item *ei; + struct btrfs_tree_block_info *bi; + struct btrfs_key key; + struct extent_buffer *eb; + u32 size = sizeof(*ei); + u32 node_size = root->fs_info->nodesize; + int insert_extent = 0; + int skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA); + int root_level = btrfs_header_level(root->node); + int generation; + int ret; + u64 owner; + u64 bytenr; + u64 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK; + u64 parent = 0; + + if ((err & BACKREF_MISSING) == 0) + return err; + + WARN_ON(level > BTRFS_MAX_LEVEL); + WARN_ON(level < 0); + + btrfs_init_path(&path); + bytenr = btrfs_header_bytenr(node); + owner = btrfs_header_owner(node); + generation = btrfs_header_generation(node); + + key.objectid = bytenr; + key.type = (u8)-1; + key.offset = (u64)-1; + + /* Search for the extent item */ + ret = btrfs_search_slot(NULL, extent_root, &key, &path, 0, 0); + if (ret <= 0) { + ret = -EIO; + goto out; + } + + ret = btrfs_previous_extent_item(extent_root, &path, bytenr); + if (ret) + insert_extent = 1; + + /* calculate if the extent item flag is full backref or not */ + if (nrefs->full_backref[level] != 0) + flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; + + /* insert an extent item */ + if (insert_extent) { + struct btrfs_disk_key copy_key; + + generation = btrfs_header_generation(node); + + if (level < root_level && nrefs->full_backref[level + 1] && + owner != root->objectid) { + flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; + } + + key.objectid = bytenr; + if (!skinny_metadata) { + key.type = BTRFS_EXTENT_ITEM_KEY; + key.offset = node_size; + size += sizeof(*bi); + } else { + key.type = BTRFS_METADATA_ITEM_KEY; + key.offset = level; + } + + btrfs_release_path(&path); + ret = btrfs_insert_empty_item(trans, extent_root, &path, &key, + size); + if (ret) + goto out; + + eb = path.nodes[0]; + ei = btrfs_item_ptr(eb, path.slots[0], struct btrfs_extent_item); + + btrfs_set_extent_refs(eb, ei, 0); + btrfs_set_extent_generation(eb, ei, generation); + btrfs_set_extent_flags(eb, ei, flags); + + if (!skinny_metadata) { + bi = (struct btrfs_tree_block_info *)(ei + 1); + memset_extent_buffer(eb, 0, (unsigned long)bi, + sizeof(*bi)); + btrfs_set_disk_key_objectid(©_key, root->objectid); + btrfs_set_disk_key_type(©_key, 0); + btrfs_set_disk_key_offset(©_key, 0); + + btrfs_set_tree_block_level(eb, bi, level); + btrfs_set_tree_block_key(eb, bi, ©_key); + } + btrfs_mark_buffer_dirty(eb); + printf("Added an extent item [%llu %u]\n", bytenr, node_size); + btrfs_update_block_group(trans, extent_root, bytenr, node_size, + 1, 0); + + nrefs->refs[level] = 0; + nrefs->full_backref[level] = + flags & BTRFS_BLOCK_FLAG_FULL_BACKREF; + btrfs_release_path(&path); + } + + if (level < root_level && nrefs->full_backref[level + 1] && + owner != root->objectid) + parent = nrefs->bytenr[level + 1]; + + /* increase the ref */ + ret = btrfs_inc_extent_ref(trans, extent_root, bytenr, node_size, + parent, root->objectid, level, 0); + + nrefs->refs[level]++; +out: + btrfs_release_path(&path); + if (ret) { + error( + "failed to repair tree block ref start %llu root %llu due to %s", + bytenr, root->objectid, strerror(-ret)); + } else { + printf("Added one tree block ref start %llu %s %llu\n", + bytenr, parent ? "parent" : "root", + parent ? parent : root->objectid); + err &= ~BACKREF_MISSING; + } + + return err; +} + static int check_inode_item(struct btrfs_root *root, struct btrfs_path *path, unsigned int ext_ref); static int check_tree_block_ref(struct btrfs_root *root, @@ -2579,6 +2721,10 @@ static int walk_down_tree_v2(struct btrfs_trans_handle *trans, ret = check_tree_block_ref(root, cur, btrfs_header_bytenr(cur), btrfs_header_level(cur), btrfs_header_owner(cur), nrefs); + + if (repair && ret) + ret = repair_tree_block_ref(trans, root, + path->nodes[*level], nrefs, *level, ret); err |= ret; if (check_all && nrefs->need_check[*level] && |