btrfs-progs/uuid-tree.c

106 lines
3.0 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 "ctree.h"
#include "transaction.h"
#include "disk-io.h"
#include "print-tree.h"
static void btrfs_uuid_to_key(const u8 *uuid, u64 *key_objectid,
u64 *key_offset)
{
*key_objectid = get_unaligned_le64(uuid);
*key_offset = get_unaligned_le64(uuid + sizeof(u64));
}
/* 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;
u64 key_objectid = 0;
u64 key_offset;
struct btrfs_ioctl_search_args search_arg;
struct btrfs_ioctl_search_header *search_header;
u32 item_size;
__le64 lesubid;
btrfs_uuid_to_key(uuid, &key_objectid, &key_offset);
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: %s\n",
(unsigned long long)key_objectid,
(unsigned long long)key_offset, ret, strerror(errno));
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);
}