48 lines
1.0 KiB
C
48 lines
1.0 KiB
C
// 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;
|
|
}
|