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 * lookup the root with the highest offset for a given objectid. The key we do
26 * find is copied into 'key'. If we find something return 0, otherwise 1, < 0
29 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
30 struct btrfs_root_item *item, struct btrfs_key *key)
32 struct btrfs_path *path;
33 struct btrfs_key search_key;
34 struct btrfs_key found_key;
35 struct extent_buffer *l;
39 search_key.objectid = objectid;
40 search_key.type = BTRFS_ROOT_ITEM_KEY;
41 search_key.offset = (u64)-1;
43 path = btrfs_alloc_path();
46 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
51 if (path->slots[0] == 0) {
56 slot = path->slots[0] - 1;
57 btrfs_item_key_to_cpu(l, &found_key, slot);
58 if (found_key.objectid != objectid ||
59 found_key.type != BTRFS_ROOT_ITEM_KEY) {
64 read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
67 memcpy(key, &found_key, sizeof(found_key));
70 btrfs_free_path(path);
74 int btrfs_set_root_node(struct btrfs_root_item *item,
75 struct extent_buffer *node)
77 btrfs_set_root_bytenr(item, node->start);
78 btrfs_set_root_level(item, btrfs_header_level(node));
79 btrfs_set_root_generation(item, btrfs_header_generation(node));
84 * copy the data in 'item' into the btree
86 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
87 *root, struct btrfs_key *key, struct btrfs_root_item
90 struct btrfs_path *path;
91 struct extent_buffer *l;
96 path = btrfs_alloc_path();
98 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
103 btrfs_print_leaf(root, path->nodes[0]);
104 printk(KERN_CRIT "unable to update root key %llu %u %llu\n",
105 (unsigned long long)key->objectid, key->type,
106 (unsigned long long)key->offset);
111 slot = path->slots[0];
112 ptr = btrfs_item_ptr_offset(l, slot);
113 write_extent_buffer(l, item, ptr, sizeof(*item));
114 btrfs_mark_buffer_dirty(path->nodes[0]);
116 btrfs_free_path(path);
120 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
121 *root, struct btrfs_key *key, struct btrfs_root_item
125 ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
130 * at mount time we want to find all the old transaction snapshots that were in
131 * the process of being deleted if we crashed. This is any root item with an
132 * offset lower than the latest root. They need to be queued for deletion to
133 * finish what was happening when we crashed.
135 int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid)
137 struct btrfs_root *dead_root;
138 struct btrfs_root_item *ri;
139 struct btrfs_key key;
140 struct btrfs_key found_key;
141 struct btrfs_path *path;
144 struct extent_buffer *leaf;
147 key.objectid = objectid;
148 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
150 path = btrfs_alloc_path();
155 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
159 leaf = path->nodes[0];
160 nritems = btrfs_header_nritems(leaf);
161 slot = path->slots[0];
162 if (slot >= nritems) {
163 ret = btrfs_next_leaf(root, path);
166 leaf = path->nodes[0];
167 nritems = btrfs_header_nritems(leaf);
168 slot = path->slots[0];
170 btrfs_item_key_to_cpu(leaf, &key, slot);
171 if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
174 if (key.objectid < objectid)
177 if (key.objectid > objectid)
180 ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
181 if (btrfs_disk_root_refs(leaf, ri) != 0)
184 memcpy(&found_key, &key, sizeof(key));
186 btrfs_release_path(path);
188 btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
190 if (IS_ERR(dead_root)) {
191 ret = PTR_ERR(dead_root);
195 ret = btrfs_add_dead_root(dead_root);
205 btrfs_free_path(path);
209 int btrfs_find_orphan_roots(struct btrfs_root *tree_root)
211 struct extent_buffer *leaf;
212 struct btrfs_path *path;
213 struct btrfs_key key;
214 struct btrfs_key root_key;
215 struct btrfs_root *root;
219 path = btrfs_alloc_path();
223 key.objectid = BTRFS_ORPHAN_OBJECTID;
224 key.type = BTRFS_ORPHAN_ITEM_KEY;
227 root_key.type = BTRFS_ROOT_ITEM_KEY;
228 root_key.offset = (u64)-1;
231 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
237 leaf = path->nodes[0];
238 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
239 ret = btrfs_next_leaf(tree_root, path);
244 leaf = path->nodes[0];
247 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
248 btrfs_release_path(path);
250 if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
251 key.type != BTRFS_ORPHAN_ITEM_KEY)
254 root_key.objectid = key.offset;
257 root = btrfs_read_fs_root_no_name(tree_root->fs_info,
263 if (ret != -ENOENT) {
268 ret = btrfs_find_dead_roots(tree_root, root_key.objectid);
275 btrfs_free_path(path);
279 /* drop the root item for 'key' from 'root' */
280 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
281 struct btrfs_key *key)
283 struct btrfs_path *path;
285 struct btrfs_root_item *ri;
286 struct extent_buffer *leaf;
288 path = btrfs_alloc_path();
291 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
296 leaf = path->nodes[0];
297 ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
299 ret = btrfs_del_item(trans, root, path);
301 btrfs_free_path(path);
305 int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
306 struct btrfs_root *tree_root,
307 u64 root_id, u64 ref_id, u64 dirid, u64 *sequence,
308 const char *name, int name_len)
311 struct btrfs_path *path;
312 struct btrfs_root_ref *ref;
313 struct extent_buffer *leaf;
314 struct btrfs_key key;
319 path = btrfs_alloc_path();
323 key.objectid = root_id;
324 key.type = BTRFS_ROOT_BACKREF_KEY;
327 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
330 leaf = path->nodes[0];
331 ref = btrfs_item_ptr(leaf, path->slots[0],
332 struct btrfs_root_ref);
334 WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
335 WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
336 ptr = (unsigned long)(ref + 1);
337 WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
338 *sequence = btrfs_root_ref_sequence(leaf, ref);
340 ret = btrfs_del_item(trans, tree_root, path);
348 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
349 btrfs_release_path(path);
350 key.objectid = ref_id;
351 key.type = BTRFS_ROOT_REF_KEY;
352 key.offset = root_id;
357 btrfs_free_path(path);
361 int btrfs_find_root_ref(struct btrfs_root *tree_root,
362 struct btrfs_path *path,
363 u64 root_id, u64 ref_id)
365 struct btrfs_key key;
368 key.objectid = root_id;
369 key.type = BTRFS_ROOT_REF_KEY;
372 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
377 * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
378 * or BTRFS_ROOT_BACKREF_KEY.
380 * The dirid, sequence, name and name_len refer to the directory entry
381 * that is referencing the root.
383 * For a forward ref, the root_id is the id of the tree referencing
384 * the root and ref_id is the id of the subvol or snapshot.
386 * For a back ref the root_id is the id of the subvol or snapshot and
387 * ref_id is the id of the tree referencing it.
389 int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
390 struct btrfs_root *tree_root,
391 u64 root_id, u64 ref_id, u64 dirid, u64 sequence,
392 const char *name, int name_len)
394 struct btrfs_key key;
396 struct btrfs_path *path;
397 struct btrfs_root_ref *ref;
398 struct extent_buffer *leaf;
401 path = btrfs_alloc_path();
405 key.objectid = root_id;
406 key.type = BTRFS_ROOT_BACKREF_KEY;
409 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
410 sizeof(*ref) + name_len);
413 leaf = path->nodes[0];
414 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
415 btrfs_set_root_ref_dirid(leaf, ref, dirid);
416 btrfs_set_root_ref_sequence(leaf, ref, sequence);
417 btrfs_set_root_ref_name_len(leaf, ref, name_len);
418 ptr = (unsigned long)(ref + 1);
419 write_extent_buffer(leaf, name, ptr, name_len);
420 btrfs_mark_buffer_dirty(leaf);
422 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
423 btrfs_release_path(path);
424 key.objectid = ref_id;
425 key.type = BTRFS_ROOT_REF_KEY;
426 key.offset = root_id;
430 btrfs_free_path(path);
435 * Old btrfs forgets to init root_item->flags and root_item->byte_limit
436 * for subvolumes. To work around this problem, we steal a bit from
437 * root_item->inode_item->flags, and use it to indicate if those fields
438 * have been properly initialized.
440 void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
442 u64 inode_flags = le64_to_cpu(root_item->inode.flags);
444 if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
445 inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
446 root_item->inode.flags = cpu_to_le64(inode_flags);
447 root_item->flags = 0;
448 root_item->byte_limit = 0;