btrfs-progs/kernel-shared/uuid-tree.c

112 lines
3.1 KiB
C

/*
* Copyright (C) STRATO AG 2013. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <uuid/uuid.h>
#include <sys/ioctl.h>
#include "kernel-shared/ctree.h"
#include "kernel-shared/transaction.h"
#include "kernel-shared/disk-io.h"
#include "kernel-shared/print-tree.h"
#include "common/utils.h"
void btrfs_uuid_to_key(const u8 *uuid, struct btrfs_key *key)
{
u64 tmp;
tmp = get_unaligned_le64(uuid);
put_unaligned_64(tmp, &key->objectid);
tmp = get_unaligned_le64(uuid + sizeof(u64));
put_unaligned_64(tmp, &key->offset);
}
/*
* Search uuid tree - mounted
*
* return -ENOENT for !found, < 0 for errors, or 0 if an item was found
*/
static int btrfs_uuid_tree_lookup_any(int fd, const u8 *uuid, u8 type,
u64 *subid)
{
int ret;
struct btrfs_ioctl_search_args search_arg;
struct btrfs_ioctl_search_header *search_header;
u32 item_size;
__le64 lesubid;
struct btrfs_key key;
key.type = type;
btrfs_uuid_to_key(uuid, &key);
memset(&search_arg, 0, sizeof(search_arg));
search_arg.key.tree_id = BTRFS_UUID_TREE_OBJECTID;
search_arg.key.min_objectid = key.objectid;
search_arg.key.max_objectid = key.objectid;
search_arg.key.min_type = type;
search_arg.key.max_type = type;
search_arg.key.min_offset = key.offset;
search_arg.key.max_offset = key.offset;
search_arg.key.max_transid = (u64)-1;
search_arg.key.nr_items = 1;
ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search_arg);
if (ret < 0) {
fprintf(stderr,
"ioctl(BTRFS_IOC_TREE_SEARCH, uuid, key %016llx, UUID_KEY, %016llx) ret=%d, error: %m\n",
(unsigned long long)key.objectid,
(unsigned long long)key.offset, ret);
ret = -ENOENT;
goto out;
}
if (search_arg.key.nr_items < 1) {
ret = -ENOENT;
goto out;
}
search_header = (struct btrfs_ioctl_search_header *)(search_arg.buf);
item_size = btrfs_search_header_len(search_header);
if ((item_size & (sizeof(u64) - 1)) || item_size == 0) {
printf("btrfs: uuid item with illegal size %lu!\n",
(unsigned long)item_size);
ret = -ENOENT;
goto out;
} else {
ret = 0;
}
/* return first stored id */
memcpy(&lesubid, search_header + 1, sizeof(lesubid));
*subid = le64_to_cpu(lesubid);
out:
return ret;
}
int btrfs_lookup_uuid_subvol_item(int fd, const u8 *uuid, u64 *subvol_id)
{
return btrfs_uuid_tree_lookup_any(fd, uuid, BTRFS_UUID_KEY_SUBVOL,
subvol_id);
}
int btrfs_lookup_uuid_received_subvol_item(int fd, const u8 *uuid,
u64 *subvol_id)
{
return btrfs_uuid_tree_lookup_any(fd, uuid,
BTRFS_UUID_KEY_RECEIVED_SUBVOL,
subvol_id);
}