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 path
= btrfs_alloc_path();
38 search_key
.objectid
= objectid
;
39 search_key
.type
= BTRFS_ROOT_ITEM_KEY
;
40 search_key
.offset
= (u64
)-1;
42 ret
= btrfs_search_slot(NULL
, root
, &search_key
, path
, 0, 0);
45 if (path
->slots
[0] == 0) {
52 slot
= path
->slots
[0] - 1;
53 btrfs_item_key_to_cpu(l
, &found_key
, slot
);
54 if (found_key
.objectid
!= objectid
) {
58 read_extent_buffer(l
, item
, btrfs_item_ptr_offset(l
, slot
),
60 memcpy(key
, &found_key
, sizeof(found_key
));
63 btrfs_free_path(path
);
67 int btrfs_update_root(struct btrfs_trans_handle
*trans
, struct btrfs_root
68 *root
, struct btrfs_key
*key
, struct btrfs_root_item
71 struct btrfs_path
*path
;
72 struct extent_buffer
*l
;
78 path
= btrfs_alloc_path();
82 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
87 slot
= path
->slots
[0];
88 ptr
= btrfs_item_ptr_offset(l
, slot
);
89 old_len
= btrfs_item_size_nr(l
, slot
);
92 * If this is the first time we update the root item which originated
93 * from an older kernel, we need to enlarge the item size to make room
94 * for the added fields.
96 if (old_len
< sizeof(*item
)) {
97 btrfs_release_path(path
);
98 ret
= btrfs_search_slot(trans
, root
, key
, path
,
104 ret
= btrfs_del_item(trans
, root
, path
);
108 btrfs_release_path(path
);
109 ret
= btrfs_insert_empty_item(trans
, root
, path
,
115 slot
= path
->slots
[0];
116 ptr
= btrfs_item_ptr_offset(l
, slot
);
120 * Update generation_v2 so at the next mount we know the new root
123 btrfs_set_root_generation_v2(item
, btrfs_root_generation(item
));
125 write_extent_buffer(l
, item
, ptr
, sizeof(*item
));
126 btrfs_mark_buffer_dirty(path
->nodes
[0]);
128 btrfs_free_path(path
);
132 int btrfs_insert_root(struct btrfs_trans_handle
*trans
, struct btrfs_root
133 *root
, struct btrfs_key
*key
, struct btrfs_root_item
139 * Make sure generation v1 and v2 match. See update_root for details.
141 btrfs_set_root_generation_v2(item
, btrfs_root_generation(item
));
142 ret
= btrfs_insert_item(trans
, root
, key
, item
, sizeof(*item
));
146 /* drop the root item for 'key' from 'root' */
147 int btrfs_del_root(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
148 struct btrfs_key
*key
)
150 struct btrfs_path
*path
;
153 path
= btrfs_alloc_path();
156 ret
= btrfs_search_slot(trans
, root
, key
, path
, -1, 1);
165 ret
= btrfs_del_item(trans
, root
, path
);
167 btrfs_free_path(path
);
172 * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
173 * or BTRFS_ROOT_BACKREF_KEY.
175 * The dirid, sequence, name and name_len refer to the directory entry
176 * that is referencing the root.
178 * For a forward ref, the root_id is the id of the tree referencing
179 * the root and ref_id is the id of the subvol or snapshot.
181 * For a back ref the root_id is the id of the subvol or snapshot and
182 * ref_id is the id of the tree referencing it.
184 int btrfs_add_root_ref(struct btrfs_trans_handle
*trans
,
185 struct btrfs_root
*tree_root
,
186 u64 root_id
, u8 type
, u64 ref_id
,
187 u64 dirid
, u64 sequence
,
188 const char *name
, int name_len
)
190 struct btrfs_key key
;
192 struct btrfs_path
*path
;
193 struct btrfs_root_ref
*ref
;
194 struct extent_buffer
*leaf
;
198 path
= btrfs_alloc_path();
202 key
.objectid
= root_id
;
206 ret
= btrfs_insert_empty_item(trans
, tree_root
, path
, &key
,
207 sizeof(*ref
) + name_len
);
210 leaf
= path
->nodes
[0];
211 ref
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_root_ref
);
212 btrfs_set_root_ref_dirid(leaf
, ref
, dirid
);
213 btrfs_set_root_ref_sequence(leaf
, ref
, sequence
);
214 btrfs_set_root_ref_name_len(leaf
, ref
, name_len
);
215 ptr
= (unsigned long)(ref
+ 1);
216 write_extent_buffer(leaf
, name
, ptr
, name_len
);
217 btrfs_mark_buffer_dirty(leaf
);
219 btrfs_free_path(path
);