ext2simg.c

   1 /*
   2  * Copyright (C) 2010 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 #define _FILE_OFFSET_BITS 64
  18 #define _LARGEFILE64_SOURCE 1
  19
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22 #include <sys/types.h>
  23 #include <sys/mman.h>
  24 #include <fcntl.h>
  25 #include <libgen.h>
  26 #include <unistd.h>
  27
  28 #include <sparse/sparse.h>
  29
  30 #include "ext4_utils.h"
  31 #include "make_ext4fs.h"
  32 #include "allocate.h"
  33
  34 #if defined(__APPLE__) && defined(__MACH__)
  35 #define off64_t off_t
  36 #endif
  37
  38 #ifndef USE_MINGW /* O_BINARY is windows-specific flag */
  39 #define O_BINARY 0
  40 #endif
  41
  42 extern struct fs_info info;
  43
  44 static int verbose = 0;
  45
  46 static void usage(char *path)
  47 {
  48         fprintf(stderr, "%s [ options ] <image or block device> <output image>\n", path);
  49         fprintf(stderr, "\n");
  50         fprintf(stderr, "  -c include CRC block\n");
  51         fprintf(stderr, "  -v verbose output\n");
  52         fprintf(stderr, "  -z gzip output\n");
  53         fprintf(stderr, "  -S don't use sparse output format\n");
  54 }
  55
  56 static int build_sparse_ext(int fd, const char *filename)
  57 {
  58         unsigned int i;
  59         unsigned int block;
  60         int start_contiguous_block;
  61         u8 *block_bitmap;
  62         off64_t ret;
  63
  64         block_bitmap = malloc(info.block_size);
  65         if (!block_bitmap)
  66                 critical_error("failed to allocate block bitmap");
  67
  68         if (aux_info.first_data_block > 0)
  69                 sparse_file_add_file(ext4_sparse_file, filename, 0,
  70                                 info.block_size * aux_info.first_data_block, 0);
  71
  72         for (i = 0; i < aux_info.groups; i++) {
  73                 u32 first_block = aux_info.first_data_block + i * info.blocks_per_group;
  74                 u32 last_block = min(info.blocks_per_group, aux_info.len_blocks - first_block);
  75
  76                 ret = lseek64(fd, (u64)info.block_size * aux_info.bg_desc[i].bg_block_bitmap,
  77                                 SEEK_SET);
  78                 if (ret < 0)
  79                         critical_error_errno("failed to seek to block group bitmap %d", i);
  80
  81                 ret = read(fd, block_bitmap, info.block_size);
  82                 if (ret < 0)
  83                         critical_error_errno("failed to read block group bitmap %d", i);
  84                 if (ret != (int)info.block_size)
  85                         critical_error("failed to read all of block group bitmap %d", i);
  86
  87                 start_contiguous_block = -1;
  88                 for (block = 0; block < last_block; block++) {
  89                         if (start_contiguous_block >= 0) {
  90                                 if (!bitmap_get_bit(block_bitmap, block)) {
  91                                         u32 start_block = first_block + start_contiguous_block;
  92                                         u32 len_blocks = block - start_contiguous_block;
  93
  94                                         sparse_file_add_file(ext4_sparse_file, filename,
  95                                                         (u64)info.block_size * start_block,
  96                                                         info.block_size * len_blocks, start_block);
  97                                         start_contiguous_block = -1;
  98                                 }
  99                         } else {
 100                                 if (bitmap_get_bit(block_bitmap, block))
 101                                         start_contiguous_block = block;
 102                         }
 103                 }
 104
 105                 if (start_contiguous_block >= 0) {
 106                         u32 start_block = first_block + start_contiguous_block;
 107                         u32 len_blocks = last_block - start_contiguous_block;
 108                         sparse_file_add_file(ext4_sparse_file, filename,
 109                                         (u64)info.block_size * start_block,
 110                                         info.block_size * len_blocks, start_block);
 111                 }
 112         }
 113
 114         return 0;
 115 }
 116
 117 int main(int argc, char **argv)
 118 {
 119         int opt;
 120         const char *in = NULL;
 121         const char *out = NULL;
 122         int gzip = 0;
 123         int sparse = 1;
 124         int infd, outfd;
 125         int crc = 0;
 126
 127         while ((opt = getopt(argc, argv, "cvzS")) != -1) {
 128                 switch (opt) {
 129                 case 'c':
 130                         crc = 1;
 131                         break;
 132                 case 'v':
 133                         verbose = 1;
 134                         break;
 135                 case 'z':
 136                         gzip = 1;
 137                         break;
 138                 case 'S':
 139                         sparse = 0;
 140                         break;
 141                 }
 142         }
 143
 144         if (optind >= argc) {
 145                 fprintf(stderr, "Expected image or block device after options\n");
 146                 usage(argv[0]);
 147                 exit(EXIT_FAILURE);
 148         }
 149
 150         in = argv[optind++];
 151
 152         if (optind >= argc) {
 153                 fprintf(stderr, "Expected output image after input image\n");
 154                 usage(argv[0]);
 155                 exit(EXIT_FAILURE);
 156         }
 157
 158         out = argv[optind++];
 159
 160         if (optind < argc) {
 161                 fprintf(stderr, "Unexpected argument: %s\n", argv[optind]);
 162                 usage(argv[0]);
 163                 exit(EXIT_FAILURE);
 164         }
 165
 166         infd = open(in, O_RDONLY);
 167
 168         if (infd < 0)
 169                 critical_error_errno("failed to open input image");
 170
 171         read_ext(infd, verbose);
 172
 173         ext4_sparse_file = sparse_file_new(info.block_size, info.len);
 174
 175         build_sparse_ext(infd, in);
 176
 177         close(infd);
 178
 179         if (strcmp(out, "-")) {
 180                 outfd = open(out, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
 181                 if (outfd < 0) {
 182                         error_errno("open");
 183                         return EXIT_FAILURE;
 184                 }
 185         } else {
 186                 outfd = STDOUT_FILENO;
 187         }
 188
 189         write_ext4_image(outfd, gzip, sparse, crc);
 190         close(outfd);
 191
 192         sparse_file_destroy(ext4_sparse_file);
 193
 194         return 0;
 195 }