// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) STRATO AG 2013. All rights reserved. */ #include <linux/uuid.h> #include <asm/unaligned.h> #include "ctree.h" #include "transaction.h" #include "disk-io.h" #include "print-tree.h" static void btrfs_uuid_to_key(u8 *uuid, u8 type, struct btrfs_key *key) { key->type = type; key->objectid = get_unaligned_le64(uuid); key->offset = get_unaligned_le64(uuid + sizeof(u64)); } /* return -ENOENT for !found, < 0 for errors, or 0 if an item was found */ static int btrfs_uuid_tree_lookup(struct btrfs_root *uuid_root, u8 *uuid, u8 type, u64 subid) { int ret; struct btrfs_path *path = NULL; struct extent_buffer *eb; int slot; u32 item_size; unsigned long offset; struct btrfs_key key; if (WARN_ON_ONCE(!uuid_root)) { ret = -ENOENT; goto out; } path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } btrfs_uuid_to_key(uuid, type, &key); ret = btrfs_search_slot(NULL, uuid_root, &key, path, 0, 0); if (ret < 0) { goto out; } else if (ret > 0) { ret = -ENOENT; goto out; } eb = path->nodes[0]; slot = path->slots[0]; item_size = btrfs_item_size_nr(eb, slot); offset = btrfs_item_ptr_offset(eb, slot); ret = -ENOENT; if (!IS_ALIGNED(item_size, sizeof(u64))) { btrfs_warn(uuid_root->fs_info, "uuid item with illegal size %lu!", (unsigned long)item_size); goto out; } while (item_size) { __le64 data; read_extent_buffer(eb, &data, offset, sizeof(data)); if (le64_to_cpu(data) == subid) { ret = 0; break; } offset += sizeof(data); item_size -= sizeof(data); } out: btrfs_free_path(path); return ret; } int btrfs_uuid_tree_add(struct btrfs_trans_handle *trans, u8 *uuid, u8 type, u64 subid_cpu) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_root *uuid_root = fs_info->uuid_root; int ret; struct btrfs_path *path = NULL; struct btrfs_key key; struct extent_buffer *eb; int slot; unsigned long offset; __le64 subid_le; ret = btrfs_uuid_tree_lookup(uuid_root, uuid, type, subid_cpu); if (ret != -ENOENT) return ret; if (WARN_ON_ONCE(!uuid_root)) { ret = -EINVAL; goto out; } btrfs_uuid_to_key(uuid, type, &key); path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } ret = btrfs_insert_empty_item(trans, uuid_root, path, &key, sizeof(subid_le)); if (ret >= 0) { /* Add an item for the type for the first time */ eb = path->nodes[0]; slot = path->slots[0]; offset = btrfs_item_ptr_offset(eb, slot); } else if (ret == -EEXIST) { /* * An item with that type already exists. * Extend the item and store the new subid at the end. */ btrfs_extend_item(fs_info, path, sizeof(subid_le)); eb = path->nodes[0]; slot = path->slots[0]; offset = btrfs_item_ptr_offset(eb, slot); offset += btrfs_item_size_nr(eb, slot) - sizeof(subid_le); } else if (ret < 0) { btrfs_warn(fs_info, "insert uuid item failed %d (0x%016llx, 0x%016llx) type %u!", ret, (unsigned long long)key.objectid, (unsigned long long)key.offset, type); goto out; } ret = 0; subid_le = cpu_to_le64(subid_cpu); write_extent_buffer(eb, &subid_le, offset, sizeof(subid_le)); btrfs_mark_buffer_dirty(eb); out: btrfs_free_path(path); return ret; } int btrfs_uuid_tree_remove(struct btrfs_trans_handle *trans, u8 *uuid, u8 type, u64 subid) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_root *uuid_root = fs_info->uuid_root; int ret; struct btrfs_path *path = NULL; struct btrfs_key key; struct extent_buffer *eb; int slot; unsigned long offset; u32 item_size; unsigned long move_dst; unsigned long move_src; unsigned long move_len; if (WARN_ON_ONCE(!uuid_root)) { ret = -EINVAL; goto out; } btrfs_uuid_to_key(uuid, type, &key); path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } ret = btrfs_search_slot(trans, uuid_root, &key, path, -1, 1); if (ret < 0) { btrfs_warn(fs_info, "error %d while searching for uuid item!", ret); goto out; } if (ret > 0) { ret = -ENOENT; goto out; } eb = path->nodes[0]; slot = path->slots[0]; offset = btrfs_item_ptr_offset(eb, slot); item_size = btrfs_item_size_nr(eb, slot); if (!IS_ALIGNED(item_size, sizeof(u64))) { btrfs_warn(fs_info, "uuid item with illegal size %lu!", (unsigned long)item_size); ret = -ENOENT; goto out; } while (item_size) { __le64 read_subid; read_extent_buffer(eb, &read_subid, offset, sizeof(read_subid)); if (le64_to_cpu(read_subid) == subid) break; offset += sizeof(read_subid); item_size -= sizeof(read_subid); } if (!item_size) { ret = -ENOENT; goto out; } item_size = btrfs_item_size_nr(eb, slot); if (item_size == sizeof(subid)) { ret = btrfs_del_item(trans, uuid_root, path); goto out; } move_dst = offset; move_src = offset + sizeof(subid); move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot)); memmove_extent_buffer(eb, move_dst, move_src, move_len); btrfs_truncate_item(fs_info, path, item_size - sizeof(subid), 1); out: btrfs_free_path(path); return ret; } static int btrfs_uuid_iter_rem(struct btrfs_root *uuid_root, u8 *uuid, u8 type, u64 subid) { struct btrfs_trans_handle *trans; int ret; /* 1 - for the uuid item */ trans = btrfs_start_transaction(uuid_root, 1); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out; } ret = btrfs_uuid_tree_remove(trans, uuid, type, subid); btrfs_end_transaction(trans); out: return ret; } int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info, int (*check_func)(struct btrfs_fs_info *, u8 *, u8, u64)) { struct btrfs_root *root = fs_info->uuid_root; struct btrfs_key key; struct btrfs_path *path; int ret = 0; struct extent_buffer *leaf; int slot; u32 item_size; unsigned long offset; path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } key.objectid = 0; key.type = 0; key.offset = 0; again_search_slot: ret = btrfs_search_forward(root, &key, path, BTRFS_OLDEST_GENERATION); if (ret) { if (ret > 0) ret = 0; goto out; } while (1) { cond_resched(); leaf = path->nodes[0]; slot = path->slots[0]; btrfs_item_key_to_cpu(leaf, &key, slot); if (key.type != BTRFS_UUID_KEY_SUBVOL && key.type != BTRFS_UUID_KEY_RECEIVED_SUBVOL) goto skip; offset = btrfs_item_ptr_offset(leaf, slot); item_size = btrfs_item_size_nr(leaf, slot); if (!IS_ALIGNED(item_size, sizeof(u64))) { btrfs_warn(fs_info, "uuid item with illegal size %lu!", (unsigned long)item_size); goto skip; } while (item_size) { u8 uuid[BTRFS_UUID_SIZE]; __le64 subid_le; u64 subid_cpu; put_unaligned_le64(key.objectid, uuid); put_unaligned_le64(key.offset, uuid + sizeof(u64)); read_extent_buffer(leaf, &subid_le, offset, sizeof(subid_le)); subid_cpu = le64_to_cpu(subid_le); ret = check_func(fs_info, uuid, key.type, subid_cpu); if (ret < 0) goto out; if (ret > 0) { btrfs_release_path(path); ret = btrfs_uuid_iter_rem(root, uuid, key.type, subid_cpu); if (ret == 0) { /* * this might look inefficient, but the * justification is that it is an * exception that check_func returns 1, * and that in the regular case only one * entry per UUID exists. */ goto again_search_slot; } if (ret < 0 && ret != -ENOENT) goto out; } item_size -= sizeof(subid_le); offset += sizeof(subid_le); } skip: ret = btrfs_next_item(root, path); if (ret == 0) continue; else if (ret > 0) ret = 0; break; } out: btrfs_free_path(path); return ret; }