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"
25 * search forward for a root, starting with objectid 'search_start'
26 * if a root key is found, the objectid we find is filled into 'found_objectid'
27 * and 0 is returned. < 0 is returned on error, 1 if there is nothing
30 int btrfs_search_root(struct btrfs_root *root, u64 search_start,
33 struct btrfs_path *path;
34 struct btrfs_key search_key;
37 root = root->fs_info->tree_root;
38 search_key.objectid = search_start;
39 search_key.type = (u8)-1;
40 search_key.offset = (u64)-1;
42 path = btrfs_alloc_path();
45 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
52 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
53 ret = btrfs_next_leaf(root, path);
57 btrfs_item_key_to_cpu(path->nodes[0], &search_key, path->slots[0]);
58 if (search_key.type != BTRFS_ROOT_ITEM_KEY) {
60 btrfs_release_path(root, path);
64 *found_objectid = search_key.objectid;
67 btrfs_free_path(path);
72 * lookup the root with the highest offset for a given objectid. The key we do
73 * find is copied into 'key'. If we find something return 0, otherwise 1, < 0
76 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
77 struct btrfs_root_item *item, struct btrfs_key *key)
79 struct btrfs_path *path;
80 struct btrfs_key search_key;
81 struct btrfs_key found_key;
82 struct extent_buffer *l;
86 search_key.objectid = objectid;
87 search_key.type = BTRFS_ROOT_ITEM_KEY;
88 search_key.offset = (u64)-1;
90 path = btrfs_alloc_path();
92 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
98 BUG_ON(path->slots[0] == 0);
99 slot = path->slots[0] - 1;
100 btrfs_item_key_to_cpu(l, &found_key, slot);
101 if (found_key.objectid != objectid) {
105 read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
107 memcpy(key, &found_key, sizeof(found_key));
110 btrfs_free_path(path);
114 int btrfs_set_root_node(struct btrfs_root_item *item,
115 struct extent_buffer *node)
117 btrfs_set_root_bytenr(item, node->start);
118 btrfs_set_root_level(item, btrfs_header_level(node));
119 btrfs_set_root_generation(item, btrfs_header_generation(node));
124 * copy the data in 'item' into the btree
126 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
127 *root, struct btrfs_key *key, struct btrfs_root_item
130 struct btrfs_path *path;
131 struct extent_buffer *l;
136 path = btrfs_alloc_path();
138 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
143 btrfs_print_leaf(root, path->nodes[0]);
144 printk(KERN_CRIT "unable to update root key %llu %u %llu\n",
145 (unsigned long long)key->objectid, key->type,
146 (unsigned long long)key->offset);
151 slot = path->slots[0];
152 ptr = btrfs_item_ptr_offset(l, slot);
153 write_extent_buffer(l, item, ptr, sizeof(*item));
154 btrfs_mark_buffer_dirty(path->nodes[0]);
156 btrfs_release_path(root, path);
157 btrfs_free_path(path);
161 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
162 *root, struct btrfs_key *key, struct btrfs_root_item
166 ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
171 * at mount time we want to find all the old transaction snapshots that were in
172 * the process of being deleted if we crashed. This is any root item with an
173 * offset lower than the latest root. They need to be queued for deletion to
174 * finish what was happening when we crashed.
176 int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid)
178 struct btrfs_root *dead_root;
179 struct btrfs_item *item;
180 struct btrfs_root_item *ri;
181 struct btrfs_key key;
182 struct btrfs_key found_key;
183 struct btrfs_path *path;
186 struct extent_buffer *leaf;
189 key.objectid = objectid;
190 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
192 path = btrfs_alloc_path();
197 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
201 leaf = path->nodes[0];
202 nritems = btrfs_header_nritems(leaf);
203 slot = path->slots[0];
204 if (slot >= nritems) {
205 ret = btrfs_next_leaf(root, path);
208 leaf = path->nodes[0];
209 nritems = btrfs_header_nritems(leaf);
210 slot = path->slots[0];
212 item = btrfs_item_nr(leaf, slot);
213 btrfs_item_key_to_cpu(leaf, &key, slot);
214 if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
217 if (key.objectid < objectid)
220 if (key.objectid > objectid)
223 ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
224 if (btrfs_disk_root_refs(leaf, ri) != 0)
227 memcpy(&found_key, &key, sizeof(key));
229 btrfs_release_path(root, path);
231 btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
233 if (IS_ERR(dead_root)) {
234 ret = PTR_ERR(dead_root);
238 ret = btrfs_add_dead_root(dead_root);
248 btrfs_free_path(path);
252 /* drop the root item for 'key' from 'root' */
253 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
254 struct btrfs_key *key)
256 struct btrfs_path *path;
259 struct btrfs_root_item *ri;
260 struct extent_buffer *leaf;
262 path = btrfs_alloc_path();
264 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
269 leaf = path->nodes[0];
270 ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
272 refs = btrfs_disk_root_refs(leaf, ri);
274 ret = btrfs_del_item(trans, root, path);
276 btrfs_release_path(root, path);
277 btrfs_free_path(path);
281 #if 0 /* this will get used when snapshot deletion is implemented */
282 int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
283 struct btrfs_root *tree_root,
284 u64 root_id, u8 type, u64 ref_id)
286 struct btrfs_key key;
288 struct btrfs_path *path;
290 path = btrfs_alloc_path();
292 key.objectid = root_id;
296 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
299 ret = btrfs_del_item(trans, tree_root, path);
302 btrfs_free_path(path);
307 int btrfs_find_root_ref(struct btrfs_root *tree_root,
308 struct btrfs_path *path,
309 u64 root_id, u64 ref_id)
311 struct btrfs_key key;
314 key.objectid = root_id;
315 key.type = BTRFS_ROOT_REF_KEY;
318 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
324 * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
325 * or BTRFS_ROOT_BACKREF_KEY.
327 * The dirid, sequence, name and name_len refer to the directory entry
328 * that is referencing the root.
330 * For a forward ref, the root_id is the id of the tree referencing
331 * the root and ref_id is the id of the subvol or snapshot.
333 * For a back ref the root_id is the id of the subvol or snapshot and
334 * ref_id is the id of the tree referencing it.
336 int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
337 struct btrfs_root *tree_root,
338 u64 root_id, u8 type, u64 ref_id,
339 u64 dirid, u64 sequence,
340 const char *name, int name_len)
342 struct btrfs_key key;
344 struct btrfs_path *path;
345 struct btrfs_root_ref *ref;
346 struct extent_buffer *leaf;
350 path = btrfs_alloc_path();
352 key.objectid = root_id;
356 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
357 sizeof(*ref) + name_len);
360 leaf = path->nodes[0];
361 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
362 btrfs_set_root_ref_dirid(leaf, ref, dirid);
363 btrfs_set_root_ref_sequence(leaf, ref, sequence);
364 btrfs_set_root_ref_name_len(leaf, ref, name_len);
365 ptr = (unsigned long)(ref + 1);
366 write_extent_buffer(leaf, name, ptr, name_len);
367 btrfs_mark_buffer_dirty(leaf);
369 btrfs_free_path(path);