X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=root-tree.c;h=6b8f8c1ce6c5cee3a810b4bc765ecfd30c67cfba;hb=19b18536d117c3e000fb9fa913081b5985127070;hp=03aa7c2c6336928a11e39662872a41059771e6a9;hpb=7a0a809b4cde0ff1712579e403d85c095b48905f;p=platform%2Fupstream%2Fbtrfs-progs.git diff --git a/root-tree.c b/root-tree.c index 03aa7c2..6b8f8c1 100644 --- a/root-tree.c +++ b/root-tree.c @@ -1,88 +1,222 @@ -#include -#include -#include "kerncompat.h" -#include "radix-tree.h" +/* + * 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 "ctree.h" +#include "transaction.h" #include "disk-io.h" #include "print-tree.h" int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct btrfs_root_item *item, struct btrfs_key *key) { - struct btrfs_path path; + struct btrfs_path *path; struct btrfs_key search_key; - struct btrfs_leaf *l; + struct btrfs_key found_key; + struct extent_buffer *l; int ret; int slot; + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + search_key.objectid = objectid; - search_key.flags = (u32)-1; - search_key.offset = (u32)-1; + search_key.type = BTRFS_ROOT_ITEM_KEY; + search_key.offset = (u64)-1; - btrfs_init_path(&path); - ret = btrfs_search_slot(root, &search_key, &path, 0, 0); + ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); if (ret < 0) goto out; + if (path->slots[0] == 0) { + ret = -ENOENT; + goto out; + } + BUG_ON(ret == 0); - l = &path.nodes[0]->leaf; - BUG_ON(path.slots[0] == 0); - slot = path.slots[0] - 1; - if (btrfs_key_objectid(&l->items[slot].key) != objectid) { - ret = 1; + l = path->nodes[0]; + slot = path->slots[0] - 1; + btrfs_item_key_to_cpu(l, &found_key, slot); + if (found_key.type != BTRFS_ROOT_ITEM_KEY || + found_key.objectid != objectid) { + ret = -ENOENT; goto out; } - memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item), - sizeof(*item)); - btrfs_disk_key_to_cpu(key, &l->items[slot].key); - btrfs_release_path(root, &path); + read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot), + sizeof(*item)); + memcpy(key, &found_key, sizeof(found_key)); ret = 0; out: + btrfs_free_path(path); return ret; } -int btrfs_update_root(struct btrfs_root *root, struct btrfs_key *key, - struct btrfs_root_item *item) +int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root + *root, struct btrfs_key *key, struct btrfs_root_item + *item) { - struct btrfs_path path; - struct btrfs_leaf *l; + struct btrfs_path *path; + struct extent_buffer *l; int ret; int slot; + unsigned long ptr; + u32 old_len; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; - btrfs_init_path(&path); - ret = btrfs_search_slot(root, key, &path, 0, 1); + ret = btrfs_search_slot(trans, root, key, path, 0, 1); if (ret < 0) goto out; BUG_ON(ret != 0); - l = &path.nodes[0]->leaf; - slot = path.slots[0]; - memcpy(btrfs_item_ptr(l, slot, struct btrfs_root_item), item, - sizeof(*item)); + l = path->nodes[0]; + slot = path->slots[0]; + ptr = btrfs_item_ptr_offset(l, slot); + old_len = btrfs_item_size_nr(l, slot); + + /* + * If this is the first time we update the root item which originated + * from an older kernel, we need to enlarge the item size to make room + * for the added fields. + */ + if (old_len < sizeof(*item)) { + btrfs_release_path(path); + ret = btrfs_search_slot(trans, root, key, path, + -1, 1); + if (ret < 0) { + goto out; + } + + ret = btrfs_del_item(trans, root, path); + if (ret < 0) { + goto out; + } + btrfs_release_path(path); + ret = btrfs_insert_empty_item(trans, root, path, + key, sizeof(*item)); + if (ret < 0) { + goto out; + } + l = path->nodes[0]; + slot = path->slots[0]; + ptr = btrfs_item_ptr_offset(l, slot); + } + + /* + * Update generation_v2 so at the next mount we know the new root + * fields are valid. + */ + btrfs_set_root_generation_v2(item, btrfs_root_generation(item)); + + write_extent_buffer(l, item, ptr, sizeof(*item)); + btrfs_mark_buffer_dirty(path->nodes[0]); out: - btrfs_release_path(root, &path); + btrfs_free_path(path); return ret; } -int btrfs_insert_root(struct btrfs_root *root, struct btrfs_key *key, - struct btrfs_root_item *item) +int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root + *root, struct btrfs_key *key, struct btrfs_root_item + *item) { int ret; - ret = btrfs_insert_item(root, key, item, sizeof(*item)); - BUG_ON(ret); + + /* + * Make sure generation v1 and v2 match. See update_root for details. + */ + btrfs_set_root_generation_v2(item, btrfs_root_generation(item)); + ret = btrfs_insert_item(trans, root, key, item, sizeof(*item)); return ret; } -int btrfs_del_root(struct btrfs_root *root, struct btrfs_key *key) +/* drop the root item for 'key' from 'root' */ +int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct btrfs_key *key) { - struct btrfs_path path; + struct btrfs_path *path; int ret; - btrfs_init_path(&path); - ret = btrfs_search_slot(root, key, &path, -1, 1); + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + ret = btrfs_search_slot(trans, root, key, path, -1, 1); if (ret < 0) goto out; - BUG_ON(ret != 0); - ret = btrfs_del_item(root, &path); + + if (ret != 0) { + ret = -ENOENT; + goto out; + } + + ret = btrfs_del_item(trans, root, path); out: - btrfs_release_path(root, &path); + btrfs_free_path(path); + return ret; +} + +/* + * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY + * or BTRFS_ROOT_BACKREF_KEY. + * + * The dirid, sequence, name and name_len refer to the directory entry + * that is referencing the root. + * + * For a forward ref, the root_id is the id of the tree referencing + * the root and ref_id is the id of the subvol or snapshot. + * + * For a back ref the root_id is the id of the subvol or snapshot and + * ref_id is the id of the tree referencing it. + */ +int btrfs_add_root_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *tree_root, + u64 root_id, u8 type, u64 ref_id, + u64 dirid, u64 sequence, + const char *name, int name_len) +{ + struct btrfs_key key; + int ret; + struct btrfs_path *path; + struct btrfs_root_ref *ref; + struct extent_buffer *leaf; + unsigned long ptr; + + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = root_id; + key.type = type; + key.offset = ref_id; + + ret = btrfs_insert_empty_item(trans, tree_root, path, &key, + sizeof(*ref) + name_len); + BUG_ON(ret); + + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); + btrfs_set_root_ref_dirid(leaf, ref, dirid); + btrfs_set_root_ref_sequence(leaf, ref, sequence); + btrfs_set_root_ref_name_len(leaf, ref, name_len); + ptr = (unsigned long)(ref + 1); + write_extent_buffer(leaf, name, ptr, name_len); + btrfs_mark_buffer_dirty(leaf); + + btrfs_free_path(path); return ret; }