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 #include "ext4_utils.h"
18 #include "make_ext4fs.h"
19 #include "output_file.h"
20 #include "backed_block.h"
21 #include "allocate.h"
22
23 #include <sys/types.h>
24 #include <sys/stat.h>
25 #include <sys/types.h>
26 #include <sys/mman.h>
27 #include <fcntl.h>
28 #include <libgen.h>
29 #include <unistd.h>
30
31 #ifndef USE_MINGW /* O_BINARY is windows-specific flag */
32 #define O_BINARY 0
33 #endif
34
35 extern struct fs_info info;
36
37 static int verbose = 0;
38
usage(char * path)39 static void usage(char *path)
40 {
41 fprintf(stderr, "%s [ options ] <image or block device> <output image>\n", path);
42 fprintf(stderr, "\n");
43 fprintf(stderr, " -c include CRC block\n");
44 fprintf(stderr, " -v verbose output\n");
45 fprintf(stderr, " -z gzip output\n");
46 fprintf(stderr, " -S don't use sparse output format\n");
47 }
48
read_ext(int fd)49 static int read_ext(int fd)
50 {
51 off64_t ret;
52 struct ext4_super_block sb;
53 unsigned int i;
54
55 ret = lseek64(fd, 1024, SEEK_SET);
56 if (ret < 0)
57 critical_error_errno("failed to seek to superblock");
58
59 ret = read(fd, &sb, sizeof(sb));
60 if (ret < 0)
61 critical_error_errno("failed to read superblock");
62 if (ret != sizeof(sb))
63 critical_error("failed to read all of superblock");
64
65 ext4_parse_sb(&sb);
66
67 ret = lseek64(fd, info.len, SEEK_SET);
68 if (ret < 0)
69 critical_error_errno("failed to seek to end of input image");
70
71 ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET);
72 if (ret < 0)
73 critical_error_errno("failed to seek to block group descriptors");
74
75 ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
76 if (ret < 0)
77 critical_error_errno("failed to read block group descriptors");
78 if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
79 critical_error("failed to read all of block group descriptors");
80
81 if (verbose) {
82 printf("Found filesystem with parameters:\n");
83 printf(" Size: %llu\n", info.len);
84 printf(" Block size: %d\n", info.block_size);
85 printf(" Blocks per group: %d\n", info.blocks_per_group);
86 printf(" Inodes per group: %d\n", info.inodes_per_group);
87 printf(" Inode size: %d\n", info.inode_size);
88 printf(" Label: %s\n", info.label);
89 printf(" Blocks: %llu\n", aux_info.len_blocks);
90 printf(" Block groups: %d\n", aux_info.groups);
91 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
92 printf(" Used %d/%d inodes and %d/%d blocks\n",
93 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
94 aux_info.sb->s_inodes_count,
95 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
96 aux_info.sb->s_blocks_count_lo);
97 }
98
99 return 0;
100 }
101
bitmap_get_bit(u8 * bitmap,u32 bit)102 static int bitmap_get_bit(u8 *bitmap, u32 bit)
103 {
104 if (bitmap[bit / 8] & 1 << (bit % 8))
105 return 1;
106
107 return 0;
108 }
109
build_sparse_ext(int fd,const char * filename)110 static int build_sparse_ext(int fd, const char *filename)
111 {
112 unsigned int i;
113 unsigned int block;
114 int start_contiguous_block;
115 u8 *block_bitmap;
116 off64_t ret;
117
118 block_bitmap = malloc(info.block_size);
119 if (!block_bitmap)
120 critical_error("failed to allocate block bitmap");
121
122 if (aux_info.first_data_block > 0)
123 queue_data_file(filename, 0,
124 info.block_size * aux_info.first_data_block, 0);
125
126 for (i = 0; i < aux_info.groups; i++) {
127 u32 first_block = aux_info.first_data_block + i * info.blocks_per_group;
128 u32 last_block = min(info.blocks_per_group, aux_info.len_blocks - first_block);
129
130 ret = lseek64(fd, (u64)info.block_size * aux_info.bg_desc[i].bg_block_bitmap,
131 SEEK_SET);
132 if (ret < 0)
133 critical_error_errno("failed to seek to block group bitmap %d", i);
134
135 ret = read(fd, block_bitmap, info.block_size);
136 if (ret < 0)
137 critical_error_errno("failed to read block group bitmap %d", i);
138 if (ret != (int)info.block_size)
139 critical_error("failed to read all of block group bitmap %d", i);
140
141 start_contiguous_block = -1;
142 for (block = 0; block < last_block; block++) {
143 if (start_contiguous_block >= 0) {
144 if (!bitmap_get_bit(block_bitmap, block)) {
145 u32 start_block = first_block + start_contiguous_block;
146 u32 len_blocks = block - start_contiguous_block;
147
148 queue_data_file(filename, (u64)info.block_size * start_block,
149 info.block_size * len_blocks, start_block);
150 start_contiguous_block = -1;
151 }
152 } else {
153 if (bitmap_get_bit(block_bitmap, block))
154 start_contiguous_block = block;
155 }
156 }
157
158 if (start_contiguous_block >= 0) {
159 u32 start_block = first_block + start_contiguous_block;
160 u32 len_blocks = last_block - start_contiguous_block;
161 queue_data_file(filename, (u64)info.block_size * start_block,
162 info.block_size * len_blocks, start_block);
163 }
164 }
165
166 return 0;
167 }
168
main(int argc,char ** argv)169 int main(int argc, char **argv)
170 {
171 int opt;
172 const char *in = NULL;
173 const char *out = NULL;
174 int gzip = 0;
175 int sparse = 1;
176 int infd, outfd;
177 int crc = 0;
178
179 while ((opt = getopt(argc, argv, "cvzS")) != -1) {
180 switch (opt) {
181 case 'c':
182 crc = 1;
183 break;
184 case 'v':
185 verbose = 1;
186 break;
187 case 'z':
188 gzip = 1;
189 break;
190 case 'S':
191 sparse = 0;
192 break;
193 }
194 }
195
196 if (optind >= argc) {
197 fprintf(stderr, "Expected image or block device after options\n");
198 usage(argv[0]);
199 exit(EXIT_FAILURE);
200 }
201
202 in = argv[optind++];
203
204 if (optind >= argc) {
205 fprintf(stderr, "Expected output image after input image\n");
206 usage(argv[0]);
207 exit(EXIT_FAILURE);
208 }
209
210 out = argv[optind++];
211
212 if (optind < argc) {
213 fprintf(stderr, "Unexpected argument: %s\n", argv[optind]);
214 usage(argv[0]);
215 exit(EXIT_FAILURE);
216 }
217
218 infd = open(in, O_RDONLY);
219
220 if (infd < 0)
221 critical_error_errno("failed to open input image");
222
223 read_ext(infd);
224
225 build_sparse_ext(infd, in);
226
227 close(infd);
228
229 if (strcmp(out, "-")) {
230 outfd = open(out, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
231 if (outfd < 0) {
232 error_errno("open");
233 return EXIT_FAILURE;
234 }
235 } else {
236 outfd = STDOUT_FILENO;
237 }
238
239 write_ext4_image(outfd, gzip, sparse, crc, 0);
240 close(outfd);
241
242 return 0;
243 }
244