2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
20 #include "transaction.h"
22 #include "print-tree.h"
24 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
25 struct btrfs_root_item *item, struct btrfs_key *key)
27 struct btrfs_path *path;
28 struct btrfs_key search_key;
29 struct btrfs_key found_key;
30 struct extent_buffer *l;
34 search_key.objectid = objectid;
35 search_key.type = BTRFS_ROOT_ITEM_KEY;
36 search_key.offset = (u64)-1;
38 path = btrfs_alloc_path();
40 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
46 BUG_ON(path->slots[0] == 0);
47 slot = path->slots[0] - 1;
48 btrfs_item_key_to_cpu(l, &found_key, slot);
49 if (found_key.objectid != objectid) {
53 read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
55 memcpy(key, &found_key, sizeof(found_key));
58 btrfs_release_path(root, path);
59 btrfs_free_path(path);
63 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
64 *root, struct btrfs_key *key, struct btrfs_root_item
67 struct btrfs_path *path;
68 struct extent_buffer *l;
74 path = btrfs_alloc_path();
76 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
81 slot = path->slots[0];
82 ptr = btrfs_item_ptr_offset(l, slot);
83 old_len = btrfs_item_size_nr(l, slot);
86 * If this is the first time we update the root item which originated
87 * from an older kernel, we need to enlarge the item size to make room
88 * for the added fields.
90 if (old_len < sizeof(*item)) {
91 btrfs_release_path(root, path);
92 ret = btrfs_search_slot(trans, root, key, path,
98 ret = btrfs_del_item(trans, root, path);
102 btrfs_release_path(root, path);
103 ret = btrfs_insert_empty_item(trans, root, path,
109 slot = path->slots[0];
110 ptr = btrfs_item_ptr_offset(l, slot);
114 * Update generation_v2 so at the next mount we know the new root
117 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
119 write_extent_buffer(l, item, ptr, sizeof(*item));
120 btrfs_mark_buffer_dirty(path->nodes[0]);
122 btrfs_release_path(root, path);
123 btrfs_free_path(path);
127 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
128 *root, struct btrfs_key *key, struct btrfs_root_item
134 * Make sure generation v1 and v2 match. See update_root for details.
136 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
137 ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
142 int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid,
143 struct btrfs_root *latest)
145 struct btrfs_root *dead_root;
146 struct btrfs_item *item;
147 struct btrfs_root_item *ri;
148 struct btrfs_key key;
149 struct btrfs_path *path;
152 struct extent_buffer *leaf;
155 key.objectid = objectid;
156 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
158 path = btrfs_alloc_path();
161 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
165 leaf = path->nodes[0];
166 nritems = btrfs_header_nritems(leaf);
167 slot = path->slots[0];
168 if (slot >= nritems) {
169 ret = btrfs_next_leaf(root, path);
172 leaf = path->nodes[0];
173 nritems = btrfs_header_nritems(leaf);
174 slot = path->slots[0];
176 item = btrfs_item_nr(leaf, slot);
177 btrfs_item_key_to_cpu(leaf, &key, slot);
178 if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
181 if (key.objectid < objectid)
184 if (key.objectid > objectid)
187 ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
188 if (btrfs_disk_root_refs(leaf, ri) != 0)
191 dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key);
192 if (IS_ERR(dead_root)) {
193 ret = PTR_ERR(dead_root);
197 ret = btrfs_add_dead_root(dead_root, latest,
198 &root->fs_info->dead_roots);
207 btrfs_free_path(path);
212 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
213 struct btrfs_key *key)
215 struct btrfs_path *path;
218 struct btrfs_root_item *ri;
219 struct extent_buffer *leaf;
221 path = btrfs_alloc_path();
223 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
227 leaf = path->nodes[0];
228 ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
230 refs = btrfs_disk_root_refs(leaf, ri);
232 ret = btrfs_del_item(trans, root, path);
234 btrfs_release_path(root, path);
235 btrfs_free_path(path);
240 * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
241 * or BTRFS_ROOT_BACKREF_KEY.
243 * The dirid, sequence, name and name_len refer to the directory entry
244 * that is referencing the root.
246 * For a forward ref, the root_id is the id of the tree referencing
247 * the root and ref_id is the id of the subvol or snapshot.
249 * For a back ref the root_id is the id of the subvol or snapshot and
250 * ref_id is the id of the tree referencing it.
252 int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
253 struct btrfs_root *tree_root,
254 u64 root_id, u8 type, u64 ref_id,
255 u64 dirid, u64 sequence,
256 const char *name, int name_len)
258 struct btrfs_key key;
260 struct btrfs_path *path;
261 struct btrfs_root_ref *ref;
262 struct extent_buffer *leaf;
266 path = btrfs_alloc_path();
268 key.objectid = root_id;
272 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
273 sizeof(*ref) + name_len);
276 leaf = path->nodes[0];
277 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
278 btrfs_set_root_ref_dirid(leaf, ref, dirid);
279 btrfs_set_root_ref_sequence(leaf, ref, sequence);
280 btrfs_set_root_ref_name_len(leaf, ref, name_len);
281 ptr = (unsigned long)(ref + 1);
282 write_extent_buffer(leaf, name, ptr, name_len);
283 btrfs_mark_buffer_dirty(leaf);
285 btrfs_free_path(path);