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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/ext4_utils.h"
18 
19 #include <fcntl.h>
20 #include <inttypes.h>
21 #include <stddef.h>
22 #include <string.h>
23 #include <sys/stat.h>
24 #include <sys/types.h>
25 
26 #include <sparse/sparse.h>
27 
28 #include "allocate.h"
29 #include "extent.h"
30 #include "indirect.h"
31 #include "sha1.h"
32 
33 #ifdef REAL_UUID
34 #include <uuid.h>
35 #endif
36 
37 #ifdef _WIN32
38 #include <winsock2.h>
39 #else
40 #include <arpa/inet.h>
41 #include <sys/ioctl.h>
42 #endif
43 
44 #if defined(__linux__)
45 #include <linux/fs.h>
46 #elif defined(__APPLE__) && defined(__MACH__)
47 #include <sys/disk.h>
48 #endif
49 
50 int force = 0;
51 struct fs_info info;
52 struct fs_aux_info aux_info;
53 struct sparse_file *ext4_sparse_file;
54 struct block_allocation *base_fs_allocations = NULL;
55 
56 jmp_buf setjmp_env;
57 
58 /* Definition from RFC-4122 */
59 struct uuid {
60     u32 time_low;
61     u16 time_mid;
62     u16 time_hi_and_version;
63     u8 clk_seq_hi_res;
64     u8 clk_seq_low;
65     u16 node0_1;
66     u32 node2_5;
67 };
68 
sha1_hash(const char * namespace,const char * name,unsigned char sha1[SHA1_DIGEST_LENGTH])69 static void sha1_hash(const char *namespace, const char *name,
70     unsigned char sha1[SHA1_DIGEST_LENGTH])
71 {
72     SHA1_CTX ctx;
73     SHA1Init(&ctx);
74     SHA1Update(&ctx, (const u8*)namespace, strlen(namespace));
75     SHA1Update(&ctx, (const u8*)name, strlen(name));
76     SHA1Final(sha1, &ctx);
77 }
78 
generate_sha1_uuid(const char * namespace,const char * name,u8 result[16])79 static void generate_sha1_uuid(const char *namespace, const char *name, u8 result[16])
80 {
81     unsigned char sha1[SHA1_DIGEST_LENGTH];
82     struct uuid *uuid = (struct uuid *)result;
83 
84     sha1_hash(namespace, name, (unsigned char*)sha1);
85     memcpy(uuid, sha1, sizeof(struct uuid));
86 
87     uuid->time_low = ntohl(uuid->time_low);
88     uuid->time_mid = ntohs(uuid->time_mid);
89     uuid->time_hi_and_version = ntohs(uuid->time_hi_and_version);
90     uuid->time_hi_and_version &= 0x0FFF;
91     uuid->time_hi_and_version |= (5 << 12);
92     uuid->clk_seq_hi_res &= ~(1 << 6);
93     uuid->clk_seq_hi_res |= 1 << 7;
94 }
95 
96 /* returns 1 if a is a power of b */
is_power_of(int a,int b)97 static int is_power_of(int a, int b)
98 {
99 	while (a > b) {
100 		if (a % b)
101 			return 0;
102 		a /= b;
103 	}
104 
105 	return (a == b) ? 1 : 0;
106 }
107 
bitmap_get_bit(u8 * bitmap,u32 bit)108 int bitmap_get_bit(u8 *bitmap, u32 bit)
109 {
110 	if (bitmap[bit / 8] & (1 << (bit % 8)))
111 		return 1;
112 
113 	return 0;
114 }
115 
bitmap_clear_bit(u8 * bitmap,u32 bit)116 void bitmap_clear_bit(u8 *bitmap, u32 bit)
117 {
118 	bitmap[bit / 8] &= ~(1 << (bit % 8));
119 
120 	return;
121 }
122 
123 /* Returns 1 if the bg contains a backup superblock.  On filesystems with
124    the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
125    and 7 have backup superblocks.  Otherwise, all block groups have backup
126    superblocks */
ext4_bg_has_super_block(int bg)127 int ext4_bg_has_super_block(int bg)
128 {
129 	/* Without sparse_super, every block group has a superblock */
130 	if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER))
131 		return 1;
132 
133 	if (bg == 0 || bg == 1)
134 		return 1;
135 
136 	if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7))
137 		return 1;
138 
139 	return 0;
140 }
141 
142 /* Function to read the primary superblock */
read_sb(int fd,struct ext4_super_block * sb)143 void read_sb(int fd, struct ext4_super_block *sb)
144 {
145 	off64_t ret;
146 
147 	ret = lseek64(fd, 1024, SEEK_SET);
148 	if (ret < 0)
149 		critical_error_errno("failed to seek to superblock");
150 
151 	ret = read(fd, sb, sizeof(*sb));
152 	if (ret < 0)
153 		critical_error_errno("failed to read superblock");
154 	if (ret != sizeof(*sb))
155 		critical_error("failed to read all of superblock");
156 }
157 
158 /* Function to write a primary or backup superblock at a given offset */
write_sb(int fd,unsigned long long offset,struct ext4_super_block * sb)159 void write_sb(int fd, unsigned long long offset, struct ext4_super_block *sb)
160 {
161 	off64_t ret;
162 
163 	ret = lseek64(fd, offset, SEEK_SET);
164 	if (ret < 0)
165 		critical_error_errno("failed to seek to superblock");
166 
167 	ret = write(fd, sb, sizeof(*sb));
168 	if (ret < 0)
169 		critical_error_errno("failed to write superblock");
170 	if (ret != sizeof(*sb))
171 		critical_error("failed to write all of superblock");
172 }
173 
block_device_write_sb(int fd)174 static void block_device_write_sb(int fd)
175 {
176 	unsigned long long offset;
177 	u32 i;
178 
179 	/* write out the backup superblocks */
180 	for (i = 1; i < aux_info.groups; i++) {
181 		if (ext4_bg_has_super_block(i)) {
182 			offset = (unsigned long long)info.block_size * (aux_info.first_data_block
183 				+ i * info.blocks_per_group);
184 			write_sb(fd, offset, aux_info.backup_sb[i]);
185 		}
186 	}
187 
188 	/* write out the primary superblock */
189 	write_sb(fd, 1024, aux_info.sb);
190 }
191 
192 /* Write the filesystem image to a file */
write_ext4_image(int fd,int gz,int sparse,int crc)193 void write_ext4_image(int fd, int gz, int sparse, int crc)
194 {
195 	sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc);
196 
197 	if (info.block_device)
198 		block_device_write_sb(fd);
199 }
200 
201 /* Compute the rest of the parameters of the filesystem from the basic info */
ext4_create_fs_aux_info()202 void ext4_create_fs_aux_info()
203 {
204 	aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
205 	aux_info.len_blocks = info.len / info.block_size;
206 	aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
207 		info.block_size);
208 	aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
209 		info.blocks_per_group);
210 	aux_info.blocks_per_ind = info.block_size / sizeof(u32);
211 	aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
212 	aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
213 
214 	aux_info.bg_desc_blocks =
215 		DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
216 			info.block_size);
217 
218 	aux_info.default_i_flags = EXT4_NOATIME_FL;
219 
220 	u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
221 	u32 last_header_size = 2 + aux_info.inode_table_blocks;
222 	if (ext4_bg_has_super_block(aux_info.groups - 1))
223 		last_header_size += 1 + aux_info.bg_desc_blocks +
224 			info.bg_desc_reserve_blocks;
225 	if (aux_info.groups <= 1 && last_group_size < last_header_size) {
226 		critical_error("filesystem size too small");
227 	}
228 	if (last_group_size > 0 && last_group_size < last_header_size) {
229 		aux_info.groups--;
230 		aux_info.len_blocks -= last_group_size;
231 	}
232 
233 	/* A zero-filled superblock to be written firstly to the block
234 	 * device to mark the file-system as invalid
235 	 */
236 	aux_info.sb_zero = calloc(1, info.block_size);
237 	if (!aux_info.sb_zero)
238 		critical_error_errno("calloc");
239 
240 	/* The write_data* functions expect only block aligned calls.
241 	 * This is not an issue, except when we write out the super
242 	 * block on a system with a block size > 1K.  So, we need to
243 	 * deal with that here.
244 	 */
245 	aux_info.sb_block = calloc(1, info.block_size);
246 	if (!aux_info.sb_block)
247 		critical_error_errno("calloc");
248 
249 	if (info.block_size > 1024)
250 		aux_info.sb = (struct ext4_super_block *)((char *)aux_info.sb_block + 1024);
251 	else
252 		aux_info.sb = aux_info.sb_block;
253 
254 	/* Alloc an array to hold the pointers to the backup superblocks */
255 	aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
256 
257 	if (!aux_info.sb)
258 		critical_error_errno("calloc");
259 
260 	aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
261 	if (!aux_info.bg_desc)
262 		critical_error_errno("calloc");
263 	aux_info.xattrs = NULL;
264 }
265 
ext4_free_fs_aux_info()266 void ext4_free_fs_aux_info()
267 {
268 	unsigned int i;
269 
270 	for (i=0; i<aux_info.groups; i++) {
271 		if (aux_info.backup_sb[i])
272 			free(aux_info.backup_sb[i]);
273 	}
274 	free(aux_info.sb_block);
275 	free(aux_info.sb_zero);
276 	free(aux_info.bg_desc);
277 }
278 
279 /* Fill in the superblock memory buffer based on the filesystem parameters */
ext4_fill_in_sb(int real_uuid)280 void ext4_fill_in_sb(int real_uuid)
281 {
282 	unsigned int i;
283 	struct ext4_super_block *sb = aux_info.sb;
284 
285 	sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
286 	sb->s_blocks_count_lo = aux_info.len_blocks;
287 	sb->s_r_blocks_count_lo = 0;
288 	sb->s_free_blocks_count_lo = 0;
289 	sb->s_free_inodes_count = 0;
290 	sb->s_first_data_block = aux_info.first_data_block;
291 	sb->s_log_block_size = log_2(info.block_size / 1024);
292 	sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
293 	sb->s_blocks_per_group = info.blocks_per_group;
294 	sb->s_obso_frags_per_group = info.blocks_per_group;
295 	sb->s_inodes_per_group = info.inodes_per_group;
296 	sb->s_mtime = 0;
297 	sb->s_wtime = 0;
298 	sb->s_mnt_count = 0;
299 	sb->s_max_mnt_count = 10;
300 	sb->s_magic = EXT4_SUPER_MAGIC;
301 	sb->s_state = EXT4_VALID_FS;
302 	sb->s_errors = EXT4_ERRORS_RO;
303 	sb->s_minor_rev_level = 0;
304 	sb->s_lastcheck = 0;
305 	sb->s_checkinterval = 0;
306 	sb->s_creator_os = EXT4_OS_LINUX;
307 	sb->s_rev_level = EXT4_DYNAMIC_REV;
308 	sb->s_def_resuid = EXT4_DEF_RESUID;
309 	sb->s_def_resgid = EXT4_DEF_RESGID;
310 
311 	sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
312 	sb->s_inode_size = info.inode_size;
313 	sb->s_block_group_nr = 0;
314 	sb->s_feature_compat = info.feat_compat;
315 	sb->s_feature_incompat = info.feat_incompat;
316 	sb->s_feature_ro_compat = info.feat_ro_compat;
317 	if (real_uuid == 1) {
318 #ifdef REAL_UUID
319 	    uuid_generate(sb->s_uuid);
320 #else
321 	    fprintf(stderr, "Not compiled with real UUID support\n");
322 	    abort();
323 #endif
324 	} else {
325 	    generate_sha1_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
326 	}
327 	memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
328 	strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
329 	memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
330 	sb->s_algorithm_usage_bitmap = 0;
331 
332 	sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks;
333 	sb->s_prealloc_blocks = 0;
334 	sb->s_prealloc_dir_blocks = 0;
335 
336 	//memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
337 	if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
338 		sb->s_journal_inum = EXT4_JOURNAL_INO;
339 	sb->s_journal_dev = 0;
340 	sb->s_last_orphan = 0;
341 	sb->s_hash_seed[0] = 0; /* FIXME */
342 	sb->s_def_hash_version = DX_HASH_TEA;
343 	sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
344 	sb->s_desc_size = sizeof(struct ext2_group_desc);
345 	sb->s_default_mount_opts = 0; /* FIXME */
346 	sb->s_first_meta_bg = 0;
347 	sb->s_mkfs_time = 0;
348 	//sb->s_jnl_blocks[17]; /* FIXME */
349 
350 	sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
351 	sb->s_r_blocks_count_hi = 0;
352 	sb->s_free_blocks_count_hi = 0;
353 	sb->s_min_extra_isize = sizeof(struct ext4_inode) -
354 		EXT4_GOOD_OLD_INODE_SIZE;
355 	sb->s_want_extra_isize = sizeof(struct ext4_inode) -
356 		EXT4_GOOD_OLD_INODE_SIZE;
357 	sb->s_flags = 2;
358 	sb->s_raid_stride = info.flash_logical_block_size / info.block_size;
359 	// stride should be the max of 8kb and logical block size
360 	if (info.flash_logical_block_size != 0 && info.flash_logical_block_size < 8192) {
361 		sb->s_raid_stride = 8192 / info.block_size;
362 	}
363 	sb->s_mmp_interval = 0;
364 	sb->s_mmp_block = 0;
365 	sb->s_raid_stripe_width = info.flash_erase_block_size / info.block_size;
366 	sb->s_log_groups_per_flex = 0;
367 	sb->s_kbytes_written = 0;
368 
369 	for (i = 0; i < aux_info.groups; i++) {
370 		u64 group_start_block = aux_info.first_data_block + i *
371 			info.blocks_per_group;
372 		u32 header_size = 0;
373 		if (ext4_bg_has_super_block(i)) {
374 			if (i != 0) {
375 				aux_info.backup_sb[i] = calloc(info.block_size, 1);
376 				memcpy(aux_info.backup_sb[i], sb, sizeof(struct ext4_super_block));
377 				/* Update the block group nr of this backup superblock */
378 				aux_info.backup_sb[i]->s_block_group_nr = i;
379 				ext4_queue_sb(group_start_block, info.block_device ?
380 						aux_info.sb_zero : aux_info.backup_sb[i]);
381 			}
382 			sparse_file_add_data(ext4_sparse_file, aux_info.bg_desc,
383 				aux_info.bg_desc_blocks * info.block_size,
384 				group_start_block + 1);
385 			header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
386 		}
387 
388 		aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
389 		aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
390 		aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
391 
392 		aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
393 		aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
394 		aux_info.bg_desc[i].bg_used_dirs_count = 0;
395 	}
396 
397 	/* Queue the primary superblock to be written out - if it's a block device,
398 	 * queue a zero-filled block first, the correct version of superblock will
399 	 * be written to the block device after all other blocks are written.
400 	 *
401 	 * The file-system on the block device will not be valid until the correct
402 	 * version of superblocks are written, this is to avoid the likelihood of a
403 	 * partially created file-system.
404 	 */
405 	ext4_queue_sb(aux_info.first_data_block, info.block_device ?
406 				aux_info.sb_zero : aux_info.sb_block);
407 }
408 
409 
ext4_queue_sb(u64 start_block,struct ext4_super_block * sb)410 void ext4_queue_sb(u64 start_block, struct ext4_super_block *sb)
411 {
412 	sparse_file_add_data(ext4_sparse_file, sb, info.block_size, start_block);
413 }
414 
ext4_parse_sb_info(struct ext4_super_block * sb)415 void ext4_parse_sb_info(struct ext4_super_block *sb)
416 {
417 	if (sb->s_magic != EXT4_SUPER_MAGIC)
418 		error("superblock magic incorrect");
419 
420 	if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
421 		error("filesystem state not valid");
422 
423 	ext4_parse_sb(sb, &info);
424 
425 	ext4_create_fs_aux_info();
426 
427 	memcpy(aux_info.sb, sb, sizeof(*sb));
428 
429 	if (aux_info.first_data_block != sb->s_first_data_block)
430 		critical_error("first data block does not match");
431 }
432 
ext4_create_resize_inode()433 void ext4_create_resize_inode()
434 {
435 	struct block_allocation *reserve_inode_alloc = create_allocation();
436 	u32 reserve_inode_len = 0;
437 	unsigned int i;
438 
439 	struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
440 	if (inode == NULL) {
441 		error("failed to get resize inode");
442 		return;
443 	}
444 
445 	for (i = 0; i < aux_info.groups; i++) {
446 		if (ext4_bg_has_super_block(i)) {
447 			u64 group_start_block = aux_info.first_data_block + i *
448 				info.blocks_per_group;
449 			u32 reserved_block_start = group_start_block + 1 +
450 				aux_info.bg_desc_blocks;
451 			u32 reserved_block_len = info.bg_desc_reserve_blocks;
452 			append_region(reserve_inode_alloc, reserved_block_start,
453 				reserved_block_len, i);
454 			reserve_inode_len += reserved_block_len;
455 		}
456 	}
457 
458 	inode_attach_resize(inode, reserve_inode_alloc);
459 
460 	inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
461 	inode->i_links_count = 1;
462 
463 	free_alloc(reserve_inode_alloc);
464 }
465 
466 /* Allocate the blocks to hold a journal inode and connect them to the
467    reserved journal inode */
ext4_create_journal_inode()468 void ext4_create_journal_inode()
469 {
470 	struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
471 	if (inode == NULL) {
472 		error("failed to get journal inode");
473 		return;
474 	}
475 
476 	u8 *journal_data = inode_allocate_data_extents(inode,
477 			info.journal_blocks * info.block_size,
478 			info.journal_blocks * info.block_size);
479 	if (!journal_data) {
480 		error("failed to allocate extents for journal data");
481 		return;
482 	}
483 
484 	inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
485 	inode->i_links_count = 1;
486 
487 	journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
488 	jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
489 	jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
490 	jsb->s_blocksize = htonl(info.block_size);
491 	jsb->s_maxlen = htonl(info.journal_blocks);
492 	jsb->s_nr_users = htonl(1);
493 	jsb->s_first = htonl(1);
494 	jsb->s_sequence = htonl(1);
495 
496 	memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
497 }
498 
499 /* Update the number of free blocks and inodes in the filesystem and in each
500    block group */
ext4_update_free()501 void ext4_update_free()
502 {
503 	u32 i;
504 
505 	for (i = 0; i < aux_info.groups; i++) {
506 		u32 bg_free_blocks = get_free_blocks(i);
507 		u32 bg_free_inodes = get_free_inodes(i);
508 		u16 crc;
509 
510 		aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
511 		aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
512 
513 		aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
514 		aux_info.sb->s_free_inodes_count += bg_free_inodes;
515 
516 		aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
517 
518 		aux_info.bg_desc[i].bg_flags = get_bg_flags(i);
519 
520 		crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid));
521 		crc = ext4_crc16(crc, &i, sizeof(i));
522 		crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum));
523 		aux_info.bg_desc[i].bg_checksum = crc;
524 	}
525 }
526 
get_block_device_size(int fd)527 u64 get_block_device_size(int fd)
528 {
529 	u64 size = 0;
530 	int ret;
531 
532 #if defined(__linux__)
533 	ret = ioctl(fd, BLKGETSIZE64, &size);
534 #elif defined(__APPLE__) && defined(__MACH__)
535 	ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
536 #else
537 	close(fd);
538 	return 0;
539 #endif
540 
541 	if (ret)
542 		return 0;
543 
544 	return size;
545 }
546 
is_block_device_fd(int fd)547 int is_block_device_fd(int fd)
548 {
549 #ifdef _WIN32
550 	return 0;
551 #else
552 	struct stat st;
553 	int ret = fstat(fd, &st);
554 	if (ret < 0)
555 		return 0;
556 
557 	return S_ISBLK(st.st_mode);
558 #endif
559 }
560 
get_file_size(int fd)561 u64 get_file_size(int fd)
562 {
563 	struct stat buf;
564 	int ret;
565 	u64 reserve_len = 0;
566 	s64 computed_size;
567 
568 	ret = fstat(fd, &buf);
569 	if (ret)
570 		return 0;
571 
572 	if (info.len < 0)
573 		reserve_len = -info.len;
574 
575 	if (S_ISREG(buf.st_mode))
576 		computed_size = buf.st_size - reserve_len;
577 	else if (S_ISBLK(buf.st_mode))
578 		computed_size = get_block_device_size(fd) - reserve_len;
579 	else
580 		computed_size = 0;
581 
582 	if (computed_size < 0) {
583 		warn("Computed filesystem size less than 0");
584 		computed_size = 0;
585 	}
586 
587 	return computed_size;
588 }
589 
parse_num(const char * arg)590 u64 parse_num(const char *arg)
591 {
592 	char *endptr;
593 	u64 num = strtoull(arg, &endptr, 10);
594 	if (*endptr == 'k' || *endptr == 'K')
595 		num *= 1024LL;
596 	else if (*endptr == 'm' || *endptr == 'M')
597 		num *= 1024LL * 1024LL;
598 	else if (*endptr == 'g' || *endptr == 'G')
599 		num *= 1024LL * 1024LL * 1024LL;
600 
601 	return num;
602 }
603 
read_ext(int fd,int verbose)604 int read_ext(int fd, int verbose)
605 {
606 	off64_t ret;
607 	struct ext4_super_block sb;
608 
609 	read_sb(fd, &sb);
610 
611 	ext4_parse_sb_info(&sb);
612 
613 	ret = lseek64(fd, info.len, SEEK_SET);
614 	if (ret < 0)
615 		critical_error_errno("failed to seek to end of input image");
616 
617 	ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET);
618 	if (ret < 0)
619 		critical_error_errno("failed to seek to block group descriptors");
620 
621 	ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
622 	if (ret < 0)
623 		critical_error_errno("failed to read block group descriptors");
624 	if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
625 		critical_error("failed to read all of block group descriptors");
626 
627 	if (verbose) {
628 		printf("Found filesystem with parameters:\n");
629 		printf("    Size: %"PRIu64"\n", info.len);
630 		printf("    Block size: %d\n", info.block_size);
631 		printf("    Blocks per group: %d\n", info.blocks_per_group);
632 		printf("    Inodes per group: %d\n", info.inodes_per_group);
633 		printf("    Inode size: %d\n", info.inode_size);
634 		printf("    Label: %s\n", info.label);
635 		printf("    Blocks: %"PRIu64"\n", aux_info.len_blocks);
636 		printf("    Block groups: %d\n", aux_info.groups);
637 		printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
638 		printf("    Used %d/%d inodes and %d/%d blocks\n",
639 			aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
640 			aux_info.sb->s_inodes_count,
641 			aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
642 			aux_info.sb->s_blocks_count_lo);
643 	}
644 
645 	return 0;
646 }
647 
648