1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "squashfs_utils.h" 18 19 #include <cutils/klog.h> 20 #include <errno.h> 21 #include <fcntl.h> 22 #include <stdlib.h> 23 #include <string.h> 24 #include <unistd.h> 25 26 #include "squashfs_fs.h" 27 28 #define ERROR(x...) KLOG_ERROR("squashfs_utils", x) 29 30 int squashfs_parse_sb(char *blk_device, struct squashfs_info *info) { 31 int ret = 0; 32 struct squashfs_super_block sb; 33 int data_device; 34 35 data_device = TEMP_FAILURE_RETRY(open(blk_device, O_RDONLY | O_CLOEXEC)); 36 if (data_device == -1) { 37 ERROR("Error opening block device (%s)\n", strerror(errno)); 38 return -1; 39 } 40 41 if (TEMP_FAILURE_RETRY(read(data_device, &sb, sizeof(sb))) 42 != sizeof(sb)) { 43 ERROR("Error reading superblock\n"); 44 ret = -1; 45 goto cleanup; 46 } 47 if (sb.s_magic != SQUASHFS_MAGIC) { 48 ERROR("Not a valid squashfs filesystem\n"); 49 ret = -1; 50 goto cleanup; 51 } 52 53 info->block_size = sb.block_size; 54 info->inodes = sb.inodes; 55 info->bytes_used = sb.bytes_used; 56 // by default mksquashfs pads the filesystem to 4K blocks 57 info->bytes_used_4K_padded = 58 sb.bytes_used + (4096 - (sb.bytes_used & (4096 - 1))); 59 60 cleanup: 61 close(data_device); 62 return ret; 63 } 64
