1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
|
// SPDX-License-Identifier: GPL-2.0+
#include "ctree.h"
int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
struct btrfs_root_item *item, struct btrfs_key *key)
{
struct btrfs_path *path;
struct btrfs_key search_key;
struct btrfs_key found_key;
struct extent_buffer *l;
int ret;
int slot;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
search_key.objectid = objectid;
search_key.type = BTRFS_ROOT_ITEM_KEY;
search_key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
if (path->slots[0] == 0) {
ret = -ENOENT;
goto out;
}
BUG_ON(ret == 0);
l = path->nodes[0];
slot = path->slots[0] - 1;
btrfs_item_key_to_cpu(l, &found_key, slot);
if (found_key.type != BTRFS_ROOT_ITEM_KEY ||
found_key.objectid != objectid) {
ret = -ENOENT;
goto out;
}
read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
sizeof(*item));
memcpy(key, &found_key, sizeof(found_key));
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
|
