| /* |
| * 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/klog.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include "squashfs_fs.h" |
| |
| #define ERROR(x...) KLOG_ERROR("squashfs_utils", x) |
| |
| int squashfs_parse_sb(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 (sb.s_magic != SQUASHFS_MAGIC) { |
| ERROR("Not a valid squashfs filesystem\n"); |
| ret = -1; |
| goto cleanup; |
| } |
| |
| 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))); |
| |
| cleanup: |
| close(data_device); |
| return ret; |
| } |