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;
73 path = btrfs_alloc_path();
75 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
80 slot = path->slots[0];
81 ptr = btrfs_item_ptr_offset(l, slot);
82 write_extent_buffer(l, item, ptr, sizeof(*item));
83 btrfs_mark_buffer_dirty(path->nodes[0]);
85 btrfs_release_path(root, path);
86 btrfs_free_path(path);
90 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
91 *root, struct btrfs_key *key, struct btrfs_root_item
97 * Make sure generation v1 and v2 match. See update_root for details.
99 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
100 ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
105 int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid,
106 struct btrfs_root *latest)
108 struct btrfs_root *dead_root;
109 struct btrfs_item *item;
110 struct btrfs_root_item *ri;
111 struct btrfs_key key;
112 struct btrfs_path *path;
115 struct extent_buffer *leaf;
118 key.objectid = objectid;
119 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
121 path = btrfs_alloc_path();
124 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
128 leaf = path->nodes[0];
129 nritems = btrfs_header_nritems(leaf);
130 slot = path->slots[0];
131 if (slot >= nritems) {
132 ret = btrfs_next_leaf(root, path);
135 leaf = path->nodes[0];
136 nritems = btrfs_header_nritems(leaf);
137 slot = path->slots[0];
139 item = btrfs_item_nr(leaf, slot);
140 btrfs_item_key_to_cpu(leaf, &key, slot);
141 if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
144 if (key.objectid < objectid)
147 if (key.objectid > objectid)
150 ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
151 if (btrfs_disk_root_refs(leaf, ri) != 0)
154 dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key);
155 if (IS_ERR(dead_root)) {
156 ret = PTR_ERR(dead_root);
160 ret = btrfs_add_dead_root(dead_root, latest,
161 &root->fs_info->dead_roots);
170 btrfs_free_path(path);
175 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
176 struct btrfs_key *key)
178 struct btrfs_path *path;
181 struct btrfs_root_item *ri;
182 struct extent_buffer *leaf;
184 path = btrfs_alloc_path();
186 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
190 leaf = path->nodes[0];
191 ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
193 refs = btrfs_disk_root_refs(leaf, ri);
195 ret = btrfs_del_item(trans, root, path);
197 btrfs_release_path(root, path);
198 btrfs_free_path(path);
203 * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
204 * or BTRFS_ROOT_BACKREF_KEY.
206 * The dirid, sequence, name and name_len refer to the directory entry
207 * that is referencing the root.
209 * For a forward ref, the root_id is the id of the tree referencing
210 * the root and ref_id is the id of the subvol or snapshot.
212 * For a back ref the root_id is the id of the subvol or snapshot and
213 * ref_id is the id of the tree referencing it.
215 int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
216 struct btrfs_root *tree_root,
217 u64 root_id, u8 type, u64 ref_id,
218 u64 dirid, u64 sequence,
219 const char *name, int name_len)
221 struct btrfs_key key;
223 struct btrfs_path *path;
224 struct btrfs_root_ref *ref;
225 struct extent_buffer *leaf;
229 path = btrfs_alloc_path();
231 key.objectid = root_id;
235 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
236 sizeof(*ref) + name_len);
239 leaf = path->nodes[0];
240 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
241 btrfs_set_root_ref_dirid(leaf, ref, dirid);
242 btrfs_set_root_ref_sequence(leaf, ref, sequence);
243 btrfs_set_root_ref_name_len(leaf, ref, name_len);
244 ptr = (unsigned long)(ref + 1);
245 write_extent_buffer(leaf, name, ptr, name_len);
246 btrfs_mark_buffer_dirty(leaf);
248 btrfs_free_path(path);