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/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "squashfs_utils.h"
#include <cutils/fs.h>
#include <cutils/klog.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "squashfs_fs.h"
#ifdef SQUASHFS_NO_KLOG
#include <stdio.h>
#define ERROR(x...) fprintf(stderr, x)
#else
#define ERROR(x...) KLOG_ERROR("squashfs_utils", x)
#endif
size_t squashfs_get_sb_size()
{
return sizeof(struct squashfs_super_block);
}
int squashfs_parse_sb_buffer(const void *buf, struct squashfs_info *info)
{
const struct squashfs_super_block *sb =
(const struct squashfs_super_block *)buf;
if (sb->s_magic != SQUASHFS_MAGIC) {
return -1;
}
info->block_size = sb->block_size;
info->inodes = sb->inodes;
info->bytes_used = sb->bytes_used;
// by default mksquashfs pads the filesystem to 4K blocks
info->bytes_used_4K_padded =
sb->bytes_used + (4096 - (sb->bytes_used & (4096 - 1)));
return 0;
}
int squashfs_parse_sb(const char *blk_device, struct squashfs_info *info)
{
int ret = 0;
struct squashfs_super_block sb;
int data_device;
data_device = TEMP_FAILURE_RETRY(open(blk_device, O_RDONLY | O_CLOEXEC));
if (data_device == -1) {
ERROR("Error opening block device (%s)\n", strerror(errno));
return -1;
}
if (TEMP_FAILURE_RETRY(read(data_device, &sb, sizeof(sb)))
!= sizeof(sb)) {
ERROR("Error reading superblock\n");
ret = -1;
goto cleanup;
}
if (squashfs_parse_sb_buffer(&sb, info) == -1) {
ERROR("Not a valid squashfs filesystem\n");
ret = -1;
goto cleanup;
}
cleanup:
close(data_device);
return ret;
}