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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2011 - 2012 Samsung Electronics
4  * EXT4 filesystem implementation in Uboot by
5  * Uma Shankar <uma.shankar@samsung.com>
6  * Manjunatha C Achar <a.manjunatha@samsung.com>
7  *
8  * ext4ls and ext4load : Based on ext2 ls load support in Uboot.
9  *
10  * (C) Copyright 2004
11  * esd gmbh <www.esd-electronics.com>
12  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
13  *
14  * based on code from grub2 fs/ext2.c and fs/fshelp.c by
15  * GRUB  --  GRand Unified Bootloader
16  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
17  *
18  * ext4write : Based on generic ext4 protocol.
19  */
20 
21 #include <common.h>
22 #include <ext_common.h>
23 #include <ext4fs.h>
24 #include <malloc.h>
25 #include <memalign.h>
26 #include <stddef.h>
27 #include <linux/stat.h>
28 #include <linux/time.h>
29 #include <asm/byteorder.h>
30 #include "ext4_common.h"
31 
32 struct ext2_data *ext4fs_root;
33 struct ext2fs_node *ext4fs_file;
34 __le32 *ext4fs_indir1_block;
35 int ext4fs_indir1_size;
36 int ext4fs_indir1_blkno = -1;
37 __le32 *ext4fs_indir2_block;
38 int ext4fs_indir2_size;
39 int ext4fs_indir2_blkno = -1;
40 
41 __le32 *ext4fs_indir3_block;
42 int ext4fs_indir3_size;
43 int ext4fs_indir3_blkno = -1;
44 struct ext2_inode *g_parent_inode;
45 static int symlinknest;
46 
47 #if defined(CONFIG_EXT4_WRITE)
ext4fs_get_group_descriptor(const struct ext_filesystem * fs,uint32_t bg_idx)48 struct ext2_block_group *ext4fs_get_group_descriptor
49 	(const struct ext_filesystem *fs, uint32_t bg_idx)
50 {
51 	return (struct ext2_block_group *)(fs->gdtable + (bg_idx * fs->gdsize));
52 }
53 
ext4fs_sb_free_inodes_dec(struct ext2_sblock * sb)54 static inline void ext4fs_sb_free_inodes_dec(struct ext2_sblock *sb)
55 {
56 	sb->free_inodes = cpu_to_le32(le32_to_cpu(sb->free_inodes) - 1);
57 }
58 
ext4fs_sb_free_blocks_dec(struct ext2_sblock * sb)59 static inline void ext4fs_sb_free_blocks_dec(struct ext2_sblock *sb)
60 {
61 	uint64_t free_blocks = le32_to_cpu(sb->free_blocks);
62 	free_blocks += (uint64_t)le32_to_cpu(sb->free_blocks_high) << 32;
63 	free_blocks--;
64 
65 	sb->free_blocks = cpu_to_le32(free_blocks & 0xffffffff);
66 	sb->free_blocks_high = cpu_to_le16(free_blocks >> 32);
67 }
68 
ext4fs_bg_free_inodes_dec(struct ext2_block_group * bg,const struct ext_filesystem * fs)69 static inline void ext4fs_bg_free_inodes_dec
70 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
71 {
72 	uint32_t free_inodes = le16_to_cpu(bg->free_inodes);
73 	if (fs->gdsize == 64)
74 		free_inodes += le16_to_cpu(bg->free_inodes_high) << 16;
75 	free_inodes--;
76 
77 	bg->free_inodes = cpu_to_le16(free_inodes & 0xffff);
78 	if (fs->gdsize == 64)
79 		bg->free_inodes_high = cpu_to_le16(free_inodes >> 16);
80 }
81 
ext4fs_bg_free_blocks_dec(struct ext2_block_group * bg,const struct ext_filesystem * fs)82 static inline void ext4fs_bg_free_blocks_dec
83 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
84 {
85 	uint32_t free_blocks = le16_to_cpu(bg->free_blocks);
86 	if (fs->gdsize == 64)
87 		free_blocks += le16_to_cpu(bg->free_blocks_high) << 16;
88 	free_blocks--;
89 
90 	bg->free_blocks = cpu_to_le16(free_blocks & 0xffff);
91 	if (fs->gdsize == 64)
92 		bg->free_blocks_high = cpu_to_le16(free_blocks >> 16);
93 }
94 
ext4fs_bg_itable_unused_dec(struct ext2_block_group * bg,const struct ext_filesystem * fs)95 static inline void ext4fs_bg_itable_unused_dec
96 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
97 {
98 	uint32_t free_inodes = le16_to_cpu(bg->bg_itable_unused);
99 	if (fs->gdsize == 64)
100 		free_inodes += le16_to_cpu(bg->bg_itable_unused_high) << 16;
101 	free_inodes--;
102 
103 	bg->bg_itable_unused = cpu_to_le16(free_inodes & 0xffff);
104 	if (fs->gdsize == 64)
105 		bg->bg_itable_unused_high = cpu_to_le16(free_inodes >> 16);
106 }
107 
ext4fs_sb_get_free_blocks(const struct ext2_sblock * sb)108 uint64_t ext4fs_sb_get_free_blocks(const struct ext2_sblock *sb)
109 {
110 	uint64_t free_blocks = le32_to_cpu(sb->free_blocks);
111 	free_blocks += (uint64_t)le32_to_cpu(sb->free_blocks_high) << 32;
112 	return free_blocks;
113 }
114 
ext4fs_sb_set_free_blocks(struct ext2_sblock * sb,uint64_t free_blocks)115 void ext4fs_sb_set_free_blocks(struct ext2_sblock *sb, uint64_t free_blocks)
116 {
117 	sb->free_blocks = cpu_to_le32(free_blocks & 0xffffffff);
118 	sb->free_blocks_high = cpu_to_le16(free_blocks >> 32);
119 }
120 
ext4fs_bg_get_free_blocks(const struct ext2_block_group * bg,const struct ext_filesystem * fs)121 uint32_t ext4fs_bg_get_free_blocks(const struct ext2_block_group *bg,
122 				   const struct ext_filesystem *fs)
123 {
124 	uint32_t free_blocks = le16_to_cpu(bg->free_blocks);
125 	if (fs->gdsize == 64)
126 		free_blocks += le16_to_cpu(bg->free_blocks_high) << 16;
127 	return free_blocks;
128 }
129 
130 static inline
ext4fs_bg_get_free_inodes(const struct ext2_block_group * bg,const struct ext_filesystem * fs)131 uint32_t ext4fs_bg_get_free_inodes(const struct ext2_block_group *bg,
132 				   const struct ext_filesystem *fs)
133 {
134 	uint32_t free_inodes = le16_to_cpu(bg->free_inodes);
135 	if (fs->gdsize == 64)
136 		free_inodes += le16_to_cpu(bg->free_inodes_high) << 16;
137 	return free_inodes;
138 }
139 
ext4fs_bg_get_flags(const struct ext2_block_group * bg)140 static inline uint16_t ext4fs_bg_get_flags(const struct ext2_block_group *bg)
141 {
142 	return le16_to_cpu(bg->bg_flags);
143 }
144 
ext4fs_bg_set_flags(struct ext2_block_group * bg,uint16_t flags)145 static inline void ext4fs_bg_set_flags(struct ext2_block_group *bg,
146 				       uint16_t flags)
147 {
148 	bg->bg_flags = cpu_to_le16(flags);
149 }
150 
151 /* Block number of the block bitmap */
ext4fs_bg_get_block_id(const struct ext2_block_group * bg,const struct ext_filesystem * fs)152 uint64_t ext4fs_bg_get_block_id(const struct ext2_block_group *bg,
153 				const struct ext_filesystem *fs)
154 {
155 	uint64_t block_nr = le32_to_cpu(bg->block_id);
156 	if (fs->gdsize == 64)
157 		block_nr += (uint64_t)le32_to_cpu(bg->block_id_high) << 32;
158 	return block_nr;
159 }
160 
161 /* Block number of the inode bitmap */
ext4fs_bg_get_inode_id(const struct ext2_block_group * bg,const struct ext_filesystem * fs)162 uint64_t ext4fs_bg_get_inode_id(const struct ext2_block_group *bg,
163 				const struct ext_filesystem *fs)
164 {
165 	uint64_t block_nr = le32_to_cpu(bg->inode_id);
166 	if (fs->gdsize == 64)
167 		block_nr += (uint64_t)le32_to_cpu(bg->inode_id_high) << 32;
168 	return block_nr;
169 }
170 #endif
171 
172 /* Block number of the inode table */
ext4fs_bg_get_inode_table_id(const struct ext2_block_group * bg,const struct ext_filesystem * fs)173 uint64_t ext4fs_bg_get_inode_table_id(const struct ext2_block_group *bg,
174 				      const struct ext_filesystem *fs)
175 {
176 	uint64_t block_nr = le32_to_cpu(bg->inode_table_id);
177 	if (fs->gdsize == 64)
178 		block_nr +=
179 			(uint64_t)le32_to_cpu(bg->inode_table_id_high) << 32;
180 	return block_nr;
181 }
182 
183 #if defined(CONFIG_EXT4_WRITE)
ext4fs_div_roundup(uint32_t size,uint32_t n)184 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n)
185 {
186 	uint32_t res = size / n;
187 	if (res * n != size)
188 		res++;
189 
190 	return res;
191 }
192 
put_ext4(uint64_t off,const void * buf,uint32_t size)193 void put_ext4(uint64_t off, const void *buf, uint32_t size)
194 {
195 	uint64_t startblock;
196 	uint64_t remainder;
197 	unsigned char *temp_ptr = NULL;
198 	struct ext_filesystem *fs = get_fs();
199 	int log2blksz = fs->dev_desc->log2blksz;
200 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, sec_buf, fs->dev_desc->blksz);
201 
202 	startblock = off >> log2blksz;
203 	startblock += part_offset;
204 	remainder = off & (uint64_t)(fs->dev_desc->blksz - 1);
205 
206 	if (fs->dev_desc == NULL)
207 		return;
208 
209 	if ((startblock + (size >> log2blksz)) >
210 	    (part_offset + fs->total_sect)) {
211 		printf("part_offset is " LBAFU "\n", part_offset);
212 		printf("total_sector is %llu\n", fs->total_sect);
213 		printf("error: overflow occurs\n");
214 		return;
215 	}
216 
217 	if (remainder) {
218 		blk_dread(fs->dev_desc, startblock, 1, sec_buf);
219 		temp_ptr = sec_buf;
220 		memcpy((temp_ptr + remainder), (unsigned char *)buf, size);
221 		blk_dwrite(fs->dev_desc, startblock, 1, sec_buf);
222 	} else {
223 		if (size >> log2blksz != 0) {
224 			blk_dwrite(fs->dev_desc, startblock, size >> log2blksz,
225 				   (unsigned long *)buf);
226 		} else {
227 			blk_dread(fs->dev_desc, startblock, 1, sec_buf);
228 			temp_ptr = sec_buf;
229 			memcpy(temp_ptr, buf, size);
230 			blk_dwrite(fs->dev_desc, startblock, 1,
231 				   (unsigned long *)sec_buf);
232 		}
233 	}
234 }
235 
_get_new_inode_no(unsigned char * buffer)236 static int _get_new_inode_no(unsigned char *buffer)
237 {
238 	struct ext_filesystem *fs = get_fs();
239 	unsigned char input;
240 	int operand, status;
241 	int count = 1;
242 	int j = 0;
243 
244 	/* get the blocksize of the filesystem */
245 	unsigned char *ptr = buffer;
246 	while (*ptr == 255) {
247 		ptr++;
248 		count += 8;
249 		if (count > le32_to_cpu(ext4fs_root->sblock.inodes_per_group))
250 			return -1;
251 	}
252 
253 	for (j = 0; j < fs->blksz; j++) {
254 		input = *ptr;
255 		int i = 0;
256 		while (i <= 7) {
257 			operand = 1 << i;
258 			status = input & operand;
259 			if (status) {
260 				i++;
261 				count++;
262 			} else {
263 				*ptr |= operand;
264 				return count;
265 			}
266 		}
267 		ptr = ptr + 1;
268 	}
269 
270 	return -1;
271 }
272 
_get_new_blk_no(unsigned char * buffer)273 static int _get_new_blk_no(unsigned char *buffer)
274 {
275 	int operand;
276 	int count = 0;
277 	int i;
278 	unsigned char *ptr = buffer;
279 	struct ext_filesystem *fs = get_fs();
280 
281 	while (*ptr == 255) {
282 		ptr++;
283 		count += 8;
284 		if (count == (fs->blksz * 8))
285 			return -1;
286 	}
287 
288 	if (fs->blksz == 1024)
289 		count += 1;
290 
291 	for (i = 0; i <= 7; i++) {
292 		operand = 1 << i;
293 		if (*ptr & operand) {
294 			count++;
295 		} else {
296 			*ptr |= operand;
297 			return count;
298 		}
299 	}
300 
301 	return -1;
302 }
303 
ext4fs_set_block_bmap(long int blockno,unsigned char * buffer,int index)304 int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index)
305 {
306 	int i, remainder, status;
307 	unsigned char *ptr = buffer;
308 	unsigned char operand;
309 	i = blockno / 8;
310 	remainder = blockno % 8;
311 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
312 
313 	i = i - (index * blocksize);
314 	if (blocksize != 1024) {
315 		ptr = ptr + i;
316 		operand = 1 << remainder;
317 		status = *ptr & operand;
318 		if (status)
319 			return -1;
320 
321 		*ptr = *ptr | operand;
322 		return 0;
323 	} else {
324 		if (remainder == 0) {
325 			ptr = ptr + i - 1;
326 			operand = (1 << 7);
327 		} else {
328 			ptr = ptr + i;
329 			operand = (1 << (remainder - 1));
330 		}
331 		status = *ptr & operand;
332 		if (status)
333 			return -1;
334 
335 		*ptr = *ptr | operand;
336 		return 0;
337 	}
338 }
339 
ext4fs_reset_block_bmap(long int blockno,unsigned char * buffer,int index)340 void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index)
341 {
342 	int i, remainder, status;
343 	unsigned char *ptr = buffer;
344 	unsigned char operand;
345 	i = blockno / 8;
346 	remainder = blockno % 8;
347 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
348 
349 	i = i - (index * blocksize);
350 	if (blocksize != 1024) {
351 		ptr = ptr + i;
352 		operand = (1 << remainder);
353 		status = *ptr & operand;
354 		if (status)
355 			*ptr = *ptr & ~(operand);
356 	} else {
357 		if (remainder == 0) {
358 			ptr = ptr + i - 1;
359 			operand = (1 << 7);
360 		} else {
361 			ptr = ptr + i;
362 			operand = (1 << (remainder - 1));
363 		}
364 		status = *ptr & operand;
365 		if (status)
366 			*ptr = *ptr & ~(operand);
367 	}
368 }
369 
ext4fs_set_inode_bmap(int inode_no,unsigned char * buffer,int index)370 int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index)
371 {
372 	int i, remainder, status;
373 	unsigned char *ptr = buffer;
374 	unsigned char operand;
375 
376 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
377 	i = inode_no / 8;
378 	remainder = inode_no % 8;
379 	if (remainder == 0) {
380 		ptr = ptr + i - 1;
381 		operand = (1 << 7);
382 	} else {
383 		ptr = ptr + i;
384 		operand = (1 << (remainder - 1));
385 	}
386 	status = *ptr & operand;
387 	if (status)
388 		return -1;
389 
390 	*ptr = *ptr | operand;
391 
392 	return 0;
393 }
394 
ext4fs_reset_inode_bmap(int inode_no,unsigned char * buffer,int index)395 void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index)
396 {
397 	int i, remainder, status;
398 	unsigned char *ptr = buffer;
399 	unsigned char operand;
400 
401 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
402 	i = inode_no / 8;
403 	remainder = inode_no % 8;
404 	if (remainder == 0) {
405 		ptr = ptr + i - 1;
406 		operand = (1 << 7);
407 	} else {
408 		ptr = ptr + i;
409 		operand = (1 << (remainder - 1));
410 	}
411 	status = *ptr & operand;
412 	if (status)
413 		*ptr = *ptr & ~(operand);
414 }
415 
ext4fs_checksum_update(uint32_t i)416 uint16_t ext4fs_checksum_update(uint32_t i)
417 {
418 	struct ext2_block_group *desc;
419 	struct ext_filesystem *fs = get_fs();
420 	uint16_t crc = 0;
421 	__le32 le32_i = cpu_to_le32(i);
422 
423 	desc = ext4fs_get_group_descriptor(fs, i);
424 	if (le32_to_cpu(fs->sb->feature_ro_compat) & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
425 		int offset = offsetof(struct ext2_block_group, bg_checksum);
426 
427 		crc = ext2fs_crc16(~0, fs->sb->unique_id,
428 				   sizeof(fs->sb->unique_id));
429 		crc = ext2fs_crc16(crc, &le32_i, sizeof(le32_i));
430 		crc = ext2fs_crc16(crc, desc, offset);
431 		offset += sizeof(desc->bg_checksum);	/* skip checksum */
432 		assert(offset == sizeof(*desc));
433 		if (offset < fs->gdsize) {
434 			crc = ext2fs_crc16(crc, (__u8 *)desc + offset,
435 					   fs->gdsize - offset);
436 		}
437 	}
438 
439 	return crc;
440 }
441 
check_void_in_dentry(struct ext2_dirent * dir,char * filename)442 static int check_void_in_dentry(struct ext2_dirent *dir, char *filename)
443 {
444 	int dentry_length;
445 	int sizeof_void_space;
446 	int new_entry_byte_reqd;
447 	short padding_factor = 0;
448 
449 	if (dir->namelen % 4 != 0)
450 		padding_factor = 4 - (dir->namelen % 4);
451 
452 	dentry_length = sizeof(struct ext2_dirent) +
453 			dir->namelen + padding_factor;
454 	sizeof_void_space = le16_to_cpu(dir->direntlen) - dentry_length;
455 	if (sizeof_void_space == 0)
456 		return 0;
457 
458 	padding_factor = 0;
459 	if (strlen(filename) % 4 != 0)
460 		padding_factor = 4 - (strlen(filename) % 4);
461 
462 	new_entry_byte_reqd = strlen(filename) +
463 	    sizeof(struct ext2_dirent) + padding_factor;
464 	if (sizeof_void_space >= new_entry_byte_reqd) {
465 		dir->direntlen = cpu_to_le16(dentry_length);
466 		return sizeof_void_space;
467 	}
468 
469 	return 0;
470 }
471 
ext4fs_update_parent_dentry(char * filename,int file_type)472 int ext4fs_update_parent_dentry(char *filename, int file_type)
473 {
474 	unsigned int *zero_buffer = NULL;
475 	char *root_first_block_buffer = NULL;
476 	int blk_idx;
477 	long int first_block_no_of_root = 0;
478 	int totalbytes = 0;
479 	unsigned int new_entry_byte_reqd;
480 	int sizeof_void_space = 0;
481 	int templength = 0;
482 	int inodeno = -1;
483 	int status;
484 	struct ext_filesystem *fs = get_fs();
485 	/* directory entry */
486 	struct ext2_dirent *dir;
487 	char *temp_dir = NULL;
488 	uint32_t new_blk_no;
489 	uint32_t new_size;
490 	uint32_t new_blockcnt;
491 	uint32_t directory_blocks;
492 
493 	zero_buffer = zalloc(fs->blksz);
494 	if (!zero_buffer) {
495 		printf("No Memory\n");
496 		return -1;
497 	}
498 	root_first_block_buffer = zalloc(fs->blksz);
499 	if (!root_first_block_buffer) {
500 		free(zero_buffer);
501 		printf("No Memory\n");
502 		return -1;
503 	}
504 	new_entry_byte_reqd = ROUND(strlen(filename) +
505 				    sizeof(struct ext2_dirent), 4);
506 restart:
507 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
508 		LOG2_BLOCK_SIZE(ext4fs_root);
509 	blk_idx = directory_blocks - 1;
510 
511 restart_read:
512 	/* read the block no allocated to a file */
513 	first_block_no_of_root = read_allocated_block(g_parent_inode, blk_idx,
514 						      NULL);
515 	if (first_block_no_of_root <= 0)
516 		goto fail;
517 
518 	status = ext4fs_devread((lbaint_t)first_block_no_of_root
519 				* fs->sect_perblk,
520 				0, fs->blksz, root_first_block_buffer);
521 	if (status == 0)
522 		goto fail;
523 
524 	if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
525 		goto fail;
526 	dir = (struct ext2_dirent *)root_first_block_buffer;
527 	totalbytes = 0;
528 
529 	while (le16_to_cpu(dir->direntlen) > 0) {
530 		unsigned short used_len = ROUND(dir->namelen +
531 		    sizeof(struct ext2_dirent), 4);
532 
533 		/* last entry of block */
534 		if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen)) {
535 
536 			/* check if new entry fits */
537 			if ((used_len + new_entry_byte_reqd) <=
538 			    le16_to_cpu(dir->direntlen)) {
539 				dir->direntlen = cpu_to_le16(used_len);
540 				break;
541 			} else {
542 				if (blk_idx > 0) {
543 					printf("Block full, trying previous\n");
544 					blk_idx--;
545 					goto restart_read;
546 				}
547 				printf("All blocks full: Allocate new\n");
548 
549 				if (le32_to_cpu(g_parent_inode->flags) &
550 						EXT4_EXTENTS_FL) {
551 					printf("Directory uses extents\n");
552 					goto fail;
553 				}
554 				if (directory_blocks >= INDIRECT_BLOCKS) {
555 					printf("Directory exceeds limit\n");
556 					goto fail;
557 				}
558 				new_blk_no = ext4fs_get_new_blk_no();
559 				if (new_blk_no == -1) {
560 					printf("no block left to assign\n");
561 					goto fail;
562 				}
563 				put_ext4((uint64_t)new_blk_no * fs->blksz, zero_buffer, fs->blksz);
564 				g_parent_inode->b.blocks.
565 					dir_blocks[directory_blocks] =
566 					cpu_to_le32(new_blk_no);
567 
568 				new_size = le32_to_cpu(g_parent_inode->size);
569 				new_size += fs->blksz;
570 				g_parent_inode->size = cpu_to_le32(new_size);
571 
572 				new_blockcnt = le32_to_cpu(g_parent_inode->blockcnt);
573 				new_blockcnt += fs->blksz >> LOG2_SECTOR_SIZE;
574 				g_parent_inode->blockcnt = cpu_to_le32(new_blockcnt);
575 
576 				if (ext4fs_put_metadata
577 				    (root_first_block_buffer,
578 				     first_block_no_of_root))
579 					goto fail;
580 				goto restart;
581 			}
582 		}
583 
584 		templength = le16_to_cpu(dir->direntlen);
585 		totalbytes = totalbytes + templength;
586 		sizeof_void_space = check_void_in_dentry(dir, filename);
587 		if (sizeof_void_space)
588 			break;
589 
590 		dir = (struct ext2_dirent *)((char *)dir + templength);
591 	}
592 
593 	/* make a pointer ready for creating next directory entry */
594 	templength = le16_to_cpu(dir->direntlen);
595 	totalbytes = totalbytes + templength;
596 	dir = (struct ext2_dirent *)((char *)dir + templength);
597 
598 	/* get the next available inode number */
599 	inodeno = ext4fs_get_new_inode_no();
600 	if (inodeno == -1) {
601 		printf("no inode left to assign\n");
602 		goto fail;
603 	}
604 	dir->inode = cpu_to_le32(inodeno);
605 	if (sizeof_void_space)
606 		dir->direntlen = cpu_to_le16(sizeof_void_space);
607 	else
608 		dir->direntlen = cpu_to_le16(fs->blksz - totalbytes);
609 
610 	dir->namelen = strlen(filename);
611 	dir->filetype = file_type;
612 	temp_dir = (char *)dir;
613 	temp_dir = temp_dir + sizeof(struct ext2_dirent);
614 	memcpy(temp_dir, filename, strlen(filename));
615 
616 	/* update or write  the 1st block of root inode */
617 	if (ext4fs_put_metadata(root_first_block_buffer,
618 				first_block_no_of_root))
619 		goto fail;
620 
621 fail:
622 	free(zero_buffer);
623 	free(root_first_block_buffer);
624 
625 	return inodeno;
626 }
627 
search_dir(struct ext2_inode * parent_inode,char * dirname)628 static int search_dir(struct ext2_inode *parent_inode, char *dirname)
629 {
630 	int status;
631 	int inodeno = 0;
632 	int offset;
633 	int blk_idx;
634 	long int blknr;
635 	char *block_buffer = NULL;
636 	struct ext2_dirent *dir = NULL;
637 	struct ext_filesystem *fs = get_fs();
638 	uint32_t directory_blocks;
639 	char *direntname;
640 
641 	directory_blocks = le32_to_cpu(parent_inode->size) >>
642 		LOG2_BLOCK_SIZE(ext4fs_root);
643 
644 	block_buffer = zalloc(fs->blksz);
645 	if (!block_buffer)
646 		goto fail;
647 
648 	/* get the block no allocated to a file */
649 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
650 		blknr = read_allocated_block(parent_inode, blk_idx, NULL);
651 		if (blknr <= 0)
652 			goto fail;
653 
654 		/* read the directory block */
655 		status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk,
656 					0, fs->blksz, (char *)block_buffer);
657 		if (status == 0)
658 			goto fail;
659 
660 		offset = 0;
661 		do {
662 			if (offset & 3) {
663 				printf("Badly aligned ext2_dirent\n");
664 				break;
665 			}
666 
667 			dir = (struct ext2_dirent *)(block_buffer + offset);
668 			direntname = (char*)(dir) + sizeof(struct ext2_dirent);
669 
670 			int direntlen = le16_to_cpu(dir->direntlen);
671 			if (direntlen < sizeof(struct ext2_dirent))
672 				break;
673 
674 			if (dir->inode && (strlen(dirname) == dir->namelen) &&
675 			    (strncmp(dirname, direntname, dir->namelen) == 0)) {
676 				inodeno = le32_to_cpu(dir->inode);
677 				break;
678 			}
679 
680 			offset += direntlen;
681 
682 		} while (offset < fs->blksz);
683 
684 		if (inodeno > 0) {
685 			free(block_buffer);
686 			return inodeno;
687 		}
688 	}
689 
690 fail:
691 	free(block_buffer);
692 
693 	return -1;
694 }
695 
find_dir_depth(char * dirname)696 static int find_dir_depth(char *dirname)
697 {
698 	char *token = strtok(dirname, "/");
699 	int count = 0;
700 	while (token != NULL) {
701 		token = strtok(NULL, "/");
702 		count++;
703 	}
704 	return count + 1 + 1;
705 	/*
706 	 * for example  for string /home/temp
707 	 * depth=home(1)+temp(1)+1 extra for NULL;
708 	 * so count is 4;
709 	 */
710 }
711 
parse_path(char ** arr,char * dirname)712 static int parse_path(char **arr, char *dirname)
713 {
714 	char *token = strtok(dirname, "/");
715 	int i = 0;
716 
717 	/* add root */
718 	arr[i] = zalloc(strlen("/") + 1);
719 	if (!arr[i])
720 		return -ENOMEM;
721 	memcpy(arr[i++], "/", strlen("/"));
722 
723 	/* add each path entry after root */
724 	while (token != NULL) {
725 		arr[i] = zalloc(strlen(token) + 1);
726 		if (!arr[i])
727 			return -ENOMEM;
728 		memcpy(arr[i++], token, strlen(token));
729 		token = strtok(NULL, "/");
730 	}
731 	arr[i] = NULL;
732 
733 	return 0;
734 }
735 
ext4fs_iget(int inode_no,struct ext2_inode * inode)736 int ext4fs_iget(int inode_no, struct ext2_inode *inode)
737 {
738 	if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0)
739 		return -1;
740 
741 	return 0;
742 }
743 
744 /*
745  * Function: ext4fs_get_parent_inode_num
746  * Return Value: inode Number of the parent directory of  file/Directory to be
747  * created
748  * dirname : Input parmater, input path name of the file/directory to be created
749  * dname : Output parameter, to be filled with the name of the directory
750  * extracted from dirname
751  */
ext4fs_get_parent_inode_num(const char * dirname,char * dname,int flags)752 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags)
753 {
754 	int i;
755 	int depth = 0;
756 	int matched_inode_no;
757 	int result_inode_no = -1;
758 	char **ptr = NULL;
759 	char *depth_dirname = NULL;
760 	char *parse_dirname = NULL;
761 	struct ext2_inode *parent_inode = NULL;
762 	struct ext2_inode *first_inode = NULL;
763 	struct ext2_inode temp_inode;
764 
765 	if (*dirname != '/') {
766 		printf("Please supply Absolute path\n");
767 		return -1;
768 	}
769 
770 	/* TODO: input validation make equivalent to linux */
771 	depth_dirname = zalloc(strlen(dirname) + 1);
772 	if (!depth_dirname)
773 		return -ENOMEM;
774 
775 	memcpy(depth_dirname, dirname, strlen(dirname));
776 	depth = find_dir_depth(depth_dirname);
777 	parse_dirname = zalloc(strlen(dirname) + 1);
778 	if (!parse_dirname)
779 		goto fail;
780 	memcpy(parse_dirname, dirname, strlen(dirname));
781 
782 	/* allocate memory for each directory level */
783 	ptr = zalloc((depth) * sizeof(char *));
784 	if (!ptr)
785 		goto fail;
786 	if (parse_path(ptr, parse_dirname))
787 		goto fail;
788 	parent_inode = zalloc(sizeof(struct ext2_inode));
789 	if (!parent_inode)
790 		goto fail;
791 	first_inode = zalloc(sizeof(struct ext2_inode));
792 	if (!first_inode)
793 		goto fail;
794 	memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode));
795 	memcpy(first_inode, parent_inode, sizeof(struct ext2_inode));
796 	if (flags & F_FILE)
797 		result_inode_no = EXT2_ROOT_INO;
798 	for (i = 1; i < depth; i++) {
799 		matched_inode_no = search_dir(parent_inode, ptr[i]);
800 		if (matched_inode_no == -1) {
801 			if (ptr[i + 1] == NULL && i == 1) {
802 				result_inode_no = EXT2_ROOT_INO;
803 				goto end;
804 			} else {
805 				if (ptr[i + 1] == NULL)
806 					break;
807 				printf("Invalid path\n");
808 				result_inode_no = -1;
809 				goto fail;
810 			}
811 		} else {
812 			if (ptr[i + 1] != NULL) {
813 				memset(parent_inode, '\0',
814 				       sizeof(struct ext2_inode));
815 				if (ext4fs_iget(matched_inode_no,
816 						parent_inode)) {
817 					result_inode_no = -1;
818 					goto fail;
819 				}
820 				result_inode_no = matched_inode_no;
821 			} else {
822 				break;
823 			}
824 		}
825 	}
826 
827 end:
828 	if (i == 1)
829 		matched_inode_no = search_dir(first_inode, ptr[i]);
830 	else
831 		matched_inode_no = search_dir(parent_inode, ptr[i]);
832 
833 	if (matched_inode_no != -1) {
834 		ext4fs_iget(matched_inode_no, &temp_inode);
835 		if (le16_to_cpu(temp_inode.mode) & S_IFDIR) {
836 			printf("It is a Directory\n");
837 			result_inode_no = -1;
838 			goto fail;
839 		}
840 	}
841 
842 	if (strlen(ptr[i]) > 256) {
843 		result_inode_no = -1;
844 		goto fail;
845 	}
846 	memcpy(dname, ptr[i], strlen(ptr[i]));
847 
848 fail:
849 	free(depth_dirname);
850 	free(parse_dirname);
851 	for (i = 0; i < depth; i++) {
852 		if (!ptr[i])
853 			break;
854 		free(ptr[i]);
855 	}
856 	free(ptr);
857 	free(parent_inode);
858 	free(first_inode);
859 
860 	return result_inode_no;
861 }
862 
unlink_filename(char * filename,unsigned int blknr)863 static int unlink_filename(char *filename, unsigned int blknr)
864 {
865 	int status;
866 	int inodeno = 0;
867 	int offset;
868 	char *block_buffer = NULL;
869 	struct ext2_dirent *dir = NULL;
870 	struct ext2_dirent *previous_dir;
871 	struct ext_filesystem *fs = get_fs();
872 	int ret = -1;
873 	char *direntname;
874 
875 	block_buffer = zalloc(fs->blksz);
876 	if (!block_buffer)
877 		return -ENOMEM;
878 
879 	/* read the directory block */
880 	status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0,
881 				fs->blksz, block_buffer);
882 	if (status == 0)
883 		goto fail;
884 
885 	offset = 0;
886 	do {
887 		if (offset & 3) {
888 			printf("Badly aligned ext2_dirent\n");
889 			break;
890 		}
891 
892 		previous_dir = dir;
893 		dir = (struct ext2_dirent *)(block_buffer + offset);
894 		direntname = (char *)(dir) + sizeof(struct ext2_dirent);
895 
896 		int direntlen = le16_to_cpu(dir->direntlen);
897 		if (direntlen < sizeof(struct ext2_dirent))
898 			break;
899 
900 		if (dir->inode && (strlen(filename) == dir->namelen) &&
901 		    (strncmp(direntname, filename, dir->namelen) == 0)) {
902 			inodeno = le32_to_cpu(dir->inode);
903 			break;
904 		}
905 
906 		offset += direntlen;
907 
908 	} while (offset < fs->blksz);
909 
910 	if (inodeno > 0) {
911 		printf("file found, deleting\n");
912 		if (ext4fs_log_journal(block_buffer, blknr))
913 			goto fail;
914 
915 		if (previous_dir) {
916 			/* merge dir entry with predecessor */
917 			uint16_t new_len;
918 			new_len = le16_to_cpu(previous_dir->direntlen);
919 			new_len += le16_to_cpu(dir->direntlen);
920 			previous_dir->direntlen = cpu_to_le16(new_len);
921 		} else {
922 			/* invalidate dir entry */
923 			dir->inode = 0;
924 		}
925 		if (ext4fs_put_metadata(block_buffer, blknr))
926 			goto fail;
927 		ret = inodeno;
928 	}
929 fail:
930 	free(block_buffer);
931 
932 	return ret;
933 }
934 
ext4fs_filename_unlink(char * filename)935 int ext4fs_filename_unlink(char *filename)
936 {
937 	int blk_idx;
938 	long int blknr = -1;
939 	int inodeno = -1;
940 	uint32_t directory_blocks;
941 
942 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
943 		LOG2_BLOCK_SIZE(ext4fs_root);
944 
945 	/* read the block no allocated to a file */
946 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
947 		blknr = read_allocated_block(g_parent_inode, blk_idx, NULL);
948 		if (blknr <= 0)
949 			break;
950 		inodeno = unlink_filename(filename, blknr);
951 		if (inodeno != -1)
952 			return inodeno;
953 	}
954 
955 	return -1;
956 }
957 
ext4fs_get_new_blk_no(void)958 uint32_t ext4fs_get_new_blk_no(void)
959 {
960 	short i;
961 	short status;
962 	int remainder;
963 	unsigned int bg_idx;
964 	static int prev_bg_bitmap_index = -1;
965 	unsigned int blk_per_grp = le32_to_cpu(ext4fs_root->sblock.blocks_per_group);
966 	struct ext_filesystem *fs = get_fs();
967 	char *journal_buffer = zalloc(fs->blksz);
968 	char *zero_buffer = zalloc(fs->blksz);
969 	if (!journal_buffer || !zero_buffer)
970 		goto fail;
971 
972 	if (fs->first_pass_bbmap == 0) {
973 		for (i = 0; i < fs->no_blkgrp; i++) {
974 			struct ext2_block_group *bgd = NULL;
975 			bgd = ext4fs_get_group_descriptor(fs, i);
976 			if (ext4fs_bg_get_free_blocks(bgd, fs)) {
977 				uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
978 				uint64_t b_bitmap_blk =
979 					ext4fs_bg_get_block_id(bgd, fs);
980 				if (bg_flags & EXT4_BG_BLOCK_UNINIT) {
981 					memcpy(fs->blk_bmaps[i], zero_buffer,
982 					       fs->blksz);
983 					put_ext4(b_bitmap_blk * fs->blksz,
984 						 fs->blk_bmaps[i], fs->blksz);
985 					bg_flags &= ~EXT4_BG_BLOCK_UNINIT;
986 					ext4fs_bg_set_flags(bgd, bg_flags);
987 				}
988 				fs->curr_blkno =
989 				    _get_new_blk_no(fs->blk_bmaps[i]);
990 				if (fs->curr_blkno == -1)
991 					/* block bitmap is completely filled */
992 					continue;
993 				fs->curr_blkno = fs->curr_blkno +
994 						(i * fs->blksz * 8);
995 				fs->first_pass_bbmap++;
996 				ext4fs_bg_free_blocks_dec(bgd, fs);
997 				ext4fs_sb_free_blocks_dec(fs->sb);
998 				status = ext4fs_devread(b_bitmap_blk *
999 							fs->sect_perblk,
1000 							0, fs->blksz,
1001 							journal_buffer);
1002 				if (status == 0)
1003 					goto fail;
1004 				if (ext4fs_log_journal(journal_buffer,
1005 						       b_bitmap_blk))
1006 					goto fail;
1007 				goto success;
1008 			} else {
1009 				debug("no space left on block group %d\n", i);
1010 			}
1011 		}
1012 
1013 		goto fail;
1014 	} else {
1015 		fs->curr_blkno++;
1016 restart:
1017 		/* get the blockbitmap index respective to blockno */
1018 		bg_idx = fs->curr_blkno / blk_per_grp;
1019 		if (fs->blksz == 1024) {
1020 			remainder = fs->curr_blkno % blk_per_grp;
1021 			if (!remainder)
1022 				bg_idx--;
1023 		}
1024 
1025 		/*
1026 		 * To skip completely filled block group bitmaps
1027 		 * Optimize the block allocation
1028 		 */
1029 		if (bg_idx >= fs->no_blkgrp)
1030 			goto fail;
1031 
1032 		struct ext2_block_group *bgd = NULL;
1033 		bgd = ext4fs_get_group_descriptor(fs, bg_idx);
1034 		if (ext4fs_bg_get_free_blocks(bgd, fs) == 0) {
1035 			debug("block group %u is full. Skipping\n", bg_idx);
1036 			fs->curr_blkno = (bg_idx + 1) * blk_per_grp;
1037 			if (fs->blksz == 1024)
1038 				fs->curr_blkno += 1;
1039 			goto restart;
1040 		}
1041 
1042 		uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1043 		uint64_t b_bitmap_blk = ext4fs_bg_get_block_id(bgd, fs);
1044 		if (bg_flags & EXT4_BG_BLOCK_UNINIT) {
1045 			memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz);
1046 			put_ext4(b_bitmap_blk * fs->blksz,
1047 				 zero_buffer, fs->blksz);
1048 			bg_flags &= ~EXT4_BG_BLOCK_UNINIT;
1049 			ext4fs_bg_set_flags(bgd, bg_flags);
1050 		}
1051 
1052 		if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx],
1053 				   bg_idx) != 0) {
1054 			debug("going for restart for the block no %ld %u\n",
1055 			      fs->curr_blkno, bg_idx);
1056 			fs->curr_blkno++;
1057 			goto restart;
1058 		}
1059 
1060 		/* journal backup */
1061 		if (prev_bg_bitmap_index != bg_idx) {
1062 			status = ext4fs_devread(b_bitmap_blk * fs->sect_perblk,
1063 						0, fs->blksz, journal_buffer);
1064 			if (status == 0)
1065 				goto fail;
1066 			if (ext4fs_log_journal(journal_buffer, b_bitmap_blk))
1067 				goto fail;
1068 
1069 			prev_bg_bitmap_index = bg_idx;
1070 		}
1071 		ext4fs_bg_free_blocks_dec(bgd, fs);
1072 		ext4fs_sb_free_blocks_dec(fs->sb);
1073 		goto success;
1074 	}
1075 success:
1076 	free(journal_buffer);
1077 	free(zero_buffer);
1078 
1079 	return fs->curr_blkno;
1080 fail:
1081 	free(journal_buffer);
1082 	free(zero_buffer);
1083 
1084 	return -1;
1085 }
1086 
ext4fs_get_new_inode_no(void)1087 int ext4fs_get_new_inode_no(void)
1088 {
1089 	short i;
1090 	short status;
1091 	unsigned int ibmap_idx;
1092 	static int prev_inode_bitmap_index = -1;
1093 	unsigned int inodes_per_grp = le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
1094 	struct ext_filesystem *fs = get_fs();
1095 	char *journal_buffer = zalloc(fs->blksz);
1096 	char *zero_buffer = zalloc(fs->blksz);
1097 	if (!journal_buffer || !zero_buffer)
1098 		goto fail;
1099 	int has_gdt_chksum = le32_to_cpu(fs->sb->feature_ro_compat) &
1100 		EXT4_FEATURE_RO_COMPAT_GDT_CSUM ? 1 : 0;
1101 
1102 	if (fs->first_pass_ibmap == 0) {
1103 		for (i = 0; i < fs->no_blkgrp; i++) {
1104 			uint32_t free_inodes;
1105 			struct ext2_block_group *bgd = NULL;
1106 			bgd = ext4fs_get_group_descriptor(fs, i);
1107 			free_inodes = ext4fs_bg_get_free_inodes(bgd, fs);
1108 			if (free_inodes) {
1109 				uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1110 				uint64_t i_bitmap_blk =
1111 					ext4fs_bg_get_inode_id(bgd, fs);
1112 				if (has_gdt_chksum)
1113 					bgd->bg_itable_unused = free_inodes;
1114 				if (bg_flags & EXT4_BG_INODE_UNINIT) {
1115 					put_ext4(i_bitmap_blk * fs->blksz,
1116 						 zero_buffer, fs->blksz);
1117 					bg_flags &= ~EXT4_BG_INODE_UNINIT;
1118 					ext4fs_bg_set_flags(bgd, bg_flags);
1119 					memcpy(fs->inode_bmaps[i],
1120 					       zero_buffer, fs->blksz);
1121 				}
1122 				fs->curr_inode_no =
1123 				    _get_new_inode_no(fs->inode_bmaps[i]);
1124 				if (fs->curr_inode_no == -1)
1125 					/* inode bitmap is completely filled */
1126 					continue;
1127 				fs->curr_inode_no = fs->curr_inode_no +
1128 							(i * inodes_per_grp);
1129 				fs->first_pass_ibmap++;
1130 				ext4fs_bg_free_inodes_dec(bgd, fs);
1131 				if (has_gdt_chksum)
1132 					ext4fs_bg_itable_unused_dec(bgd, fs);
1133 				ext4fs_sb_free_inodes_dec(fs->sb);
1134 				status = ext4fs_devread(i_bitmap_blk *
1135 							fs->sect_perblk,
1136 							0, fs->blksz,
1137 							journal_buffer);
1138 				if (status == 0)
1139 					goto fail;
1140 				if (ext4fs_log_journal(journal_buffer,
1141 						       i_bitmap_blk))
1142 					goto fail;
1143 				goto success;
1144 			} else
1145 				debug("no inode left on block group %d\n", i);
1146 		}
1147 		goto fail;
1148 	} else {
1149 restart:
1150 		fs->curr_inode_no++;
1151 		/* get the blockbitmap index respective to blockno */
1152 		ibmap_idx = fs->curr_inode_no / inodes_per_grp;
1153 		struct ext2_block_group *bgd =
1154 			ext4fs_get_group_descriptor(fs, ibmap_idx);
1155 		uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1156 		uint64_t i_bitmap_blk = ext4fs_bg_get_inode_id(bgd, fs);
1157 
1158 		if (bg_flags & EXT4_BG_INODE_UNINIT) {
1159 			put_ext4(i_bitmap_blk * fs->blksz,
1160 				 zero_buffer, fs->blksz);
1161 			bg_flags &= ~EXT4_BG_INODE_UNINIT;
1162 			ext4fs_bg_set_flags(bgd, bg_flags);
1163 			memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer,
1164 				fs->blksz);
1165 		}
1166 
1167 		if (ext4fs_set_inode_bmap(fs->curr_inode_no,
1168 					  fs->inode_bmaps[ibmap_idx],
1169 					  ibmap_idx) != 0) {
1170 			debug("going for restart for the block no %d %u\n",
1171 			      fs->curr_inode_no, ibmap_idx);
1172 			goto restart;
1173 		}
1174 
1175 		/* journal backup */
1176 		if (prev_inode_bitmap_index != ibmap_idx) {
1177 			status = ext4fs_devread(i_bitmap_blk * fs->sect_perblk,
1178 						0, fs->blksz, journal_buffer);
1179 			if (status == 0)
1180 				goto fail;
1181 			if (ext4fs_log_journal(journal_buffer,
1182 						le32_to_cpu(bgd->inode_id)))
1183 				goto fail;
1184 			prev_inode_bitmap_index = ibmap_idx;
1185 		}
1186 		ext4fs_bg_free_inodes_dec(bgd, fs);
1187 		if (has_gdt_chksum)
1188 			bgd->bg_itable_unused = bgd->free_inodes;
1189 		ext4fs_sb_free_inodes_dec(fs->sb);
1190 		goto success;
1191 	}
1192 
1193 success:
1194 	free(journal_buffer);
1195 	free(zero_buffer);
1196 
1197 	return fs->curr_inode_no;
1198 fail:
1199 	free(journal_buffer);
1200 	free(zero_buffer);
1201 
1202 	return -1;
1203 
1204 }
1205 
1206 
alloc_single_indirect_block(struct ext2_inode * file_inode,unsigned int * total_remaining_blocks,unsigned int * no_blks_reqd)1207 static void alloc_single_indirect_block(struct ext2_inode *file_inode,
1208 					unsigned int *total_remaining_blocks,
1209 					unsigned int *no_blks_reqd)
1210 {
1211 	short i;
1212 	short status;
1213 	long int actual_block_no;
1214 	long int si_blockno;
1215 	/* si :single indirect */
1216 	__le32 *si_buffer = NULL;
1217 	__le32 *si_start_addr = NULL;
1218 	struct ext_filesystem *fs = get_fs();
1219 
1220 	if (*total_remaining_blocks != 0) {
1221 		si_buffer = zalloc(fs->blksz);
1222 		if (!si_buffer) {
1223 			printf("No Memory\n");
1224 			return;
1225 		}
1226 		si_start_addr = si_buffer;
1227 		si_blockno = ext4fs_get_new_blk_no();
1228 		if (si_blockno == -1) {
1229 			printf("no block left to assign\n");
1230 			goto fail;
1231 		}
1232 		(*no_blks_reqd)++;
1233 		debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks);
1234 
1235 		status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk,
1236 					0, fs->blksz, (char *)si_buffer);
1237 		memset(si_buffer, '\0', fs->blksz);
1238 		if (status == 0)
1239 			goto fail;
1240 
1241 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1242 			actual_block_no = ext4fs_get_new_blk_no();
1243 			if (actual_block_no == -1) {
1244 				printf("no block left to assign\n");
1245 				goto fail;
1246 			}
1247 			*si_buffer = cpu_to_le32(actual_block_no);
1248 			debug("SIAB %u: %u\n", *si_buffer,
1249 				*total_remaining_blocks);
1250 
1251 			si_buffer++;
1252 			(*total_remaining_blocks)--;
1253 			if (*total_remaining_blocks == 0)
1254 				break;
1255 		}
1256 
1257 		/* write the block to disk */
1258 		put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)),
1259 			 si_start_addr, fs->blksz);
1260 		file_inode->b.blocks.indir_block = cpu_to_le32(si_blockno);
1261 	}
1262 fail:
1263 	free(si_start_addr);
1264 }
1265 
alloc_double_indirect_block(struct ext2_inode * file_inode,unsigned int * total_remaining_blocks,unsigned int * no_blks_reqd)1266 static void alloc_double_indirect_block(struct ext2_inode *file_inode,
1267 					unsigned int *total_remaining_blocks,
1268 					unsigned int *no_blks_reqd)
1269 {
1270 	short i;
1271 	short j;
1272 	short status;
1273 	long int actual_block_no;
1274 	/* di:double indirect */
1275 	long int di_blockno_parent;
1276 	long int di_blockno_child;
1277 	__le32 *di_parent_buffer = NULL;
1278 	__le32 *di_child_buff = NULL;
1279 	__le32 *di_block_start_addr = NULL;
1280 	__le32 *di_child_buff_start = NULL;
1281 	struct ext_filesystem *fs = get_fs();
1282 
1283 	if (*total_remaining_blocks != 0) {
1284 		/* double indirect parent block connecting to inode */
1285 		di_blockno_parent = ext4fs_get_new_blk_no();
1286 		if (di_blockno_parent == -1) {
1287 			printf("no block left to assign\n");
1288 			goto fail;
1289 		}
1290 		di_parent_buffer = zalloc(fs->blksz);
1291 		if (!di_parent_buffer)
1292 			goto fail;
1293 
1294 		di_block_start_addr = di_parent_buffer;
1295 		(*no_blks_reqd)++;
1296 		debug("DIPB %ld: %u\n", di_blockno_parent,
1297 		      *total_remaining_blocks);
1298 
1299 		status = ext4fs_devread((lbaint_t)di_blockno_parent *
1300 					fs->sect_perblk, 0,
1301 					fs->blksz, (char *)di_parent_buffer);
1302 
1303 		if (!status) {
1304 			printf("%s: Device read error!\n", __func__);
1305 			goto fail;
1306 		}
1307 		memset(di_parent_buffer, '\0', fs->blksz);
1308 
1309 		/*
1310 		 * start:for each double indirect parent
1311 		 * block create one more block
1312 		 */
1313 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1314 			di_blockno_child = ext4fs_get_new_blk_no();
1315 			if (di_blockno_child == -1) {
1316 				printf("no block left to assign\n");
1317 				goto fail;
1318 			}
1319 			di_child_buff = zalloc(fs->blksz);
1320 			if (!di_child_buff)
1321 				goto fail;
1322 
1323 			di_child_buff_start = di_child_buff;
1324 			*di_parent_buffer = cpu_to_le32(di_blockno_child);
1325 			di_parent_buffer++;
1326 			(*no_blks_reqd)++;
1327 			debug("DICB %ld: %u\n", di_blockno_child,
1328 			      *total_remaining_blocks);
1329 
1330 			status = ext4fs_devread((lbaint_t)di_blockno_child *
1331 						fs->sect_perblk, 0,
1332 						fs->blksz,
1333 						(char *)di_child_buff);
1334 
1335 			if (!status) {
1336 				printf("%s: Device read error!\n", __func__);
1337 				goto fail;
1338 			}
1339 			memset(di_child_buff, '\0', fs->blksz);
1340 			/* filling of actual datablocks for each child */
1341 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1342 				actual_block_no = ext4fs_get_new_blk_no();
1343 				if (actual_block_no == -1) {
1344 					printf("no block left to assign\n");
1345 					goto fail;
1346 				}
1347 				*di_child_buff = cpu_to_le32(actual_block_no);
1348 				debug("DIAB %ld: %u\n", actual_block_no,
1349 				      *total_remaining_blocks);
1350 
1351 				di_child_buff++;
1352 				(*total_remaining_blocks)--;
1353 				if (*total_remaining_blocks == 0)
1354 					break;
1355 			}
1356 			/* write the block  table */
1357 			put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)),
1358 				 di_child_buff_start, fs->blksz);
1359 			free(di_child_buff_start);
1360 			di_child_buff_start = NULL;
1361 
1362 			if (*total_remaining_blocks == 0)
1363 				break;
1364 		}
1365 		put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)),
1366 			 di_block_start_addr, fs->blksz);
1367 		file_inode->b.blocks.double_indir_block = cpu_to_le32(di_blockno_parent);
1368 	}
1369 fail:
1370 	free(di_block_start_addr);
1371 }
1372 
alloc_triple_indirect_block(struct ext2_inode * file_inode,unsigned int * total_remaining_blocks,unsigned int * no_blks_reqd)1373 static void alloc_triple_indirect_block(struct ext2_inode *file_inode,
1374 					unsigned int *total_remaining_blocks,
1375 					unsigned int *no_blks_reqd)
1376 {
1377 	short i;
1378 	short j;
1379 	short k;
1380 	long int actual_block_no;
1381 	/* ti: Triple Indirect */
1382 	long int ti_gp_blockno;
1383 	long int ti_parent_blockno;
1384 	long int ti_child_blockno;
1385 	__le32 *ti_gp_buff = NULL;
1386 	__le32 *ti_parent_buff = NULL;
1387 	__le32 *ti_child_buff = NULL;
1388 	__le32 *ti_gp_buff_start_addr = NULL;
1389 	__le32 *ti_pbuff_start_addr = NULL;
1390 	__le32 *ti_cbuff_start_addr = NULL;
1391 	struct ext_filesystem *fs = get_fs();
1392 	if (*total_remaining_blocks != 0) {
1393 		/* triple indirect grand parent block connecting to inode */
1394 		ti_gp_blockno = ext4fs_get_new_blk_no();
1395 		if (ti_gp_blockno == -1) {
1396 			printf("no block left to assign\n");
1397 			return;
1398 		}
1399 		ti_gp_buff = zalloc(fs->blksz);
1400 		if (!ti_gp_buff)
1401 			return;
1402 
1403 		ti_gp_buff_start_addr = ti_gp_buff;
1404 		(*no_blks_reqd)++;
1405 		debug("TIGPB %ld: %u\n", ti_gp_blockno,
1406 		      *total_remaining_blocks);
1407 
1408 		/* for each 4 byte grand parent entry create one more block */
1409 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1410 			ti_parent_blockno = ext4fs_get_new_blk_no();
1411 			if (ti_parent_blockno == -1) {
1412 				printf("no block left to assign\n");
1413 				goto fail;
1414 			}
1415 			ti_parent_buff = zalloc(fs->blksz);
1416 			if (!ti_parent_buff)
1417 				goto fail;
1418 
1419 			ti_pbuff_start_addr = ti_parent_buff;
1420 			*ti_gp_buff = cpu_to_le32(ti_parent_blockno);
1421 			ti_gp_buff++;
1422 			(*no_blks_reqd)++;
1423 			debug("TIPB %ld: %u\n", ti_parent_blockno,
1424 			      *total_remaining_blocks);
1425 
1426 			/* for each 4 byte entry parent create one more block */
1427 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1428 				ti_child_blockno = ext4fs_get_new_blk_no();
1429 				if (ti_child_blockno == -1) {
1430 					printf("no block left assign\n");
1431 					goto fail1;
1432 				}
1433 				ti_child_buff = zalloc(fs->blksz);
1434 				if (!ti_child_buff)
1435 					goto fail1;
1436 
1437 				ti_cbuff_start_addr = ti_child_buff;
1438 				*ti_parent_buff = cpu_to_le32(ti_child_blockno);
1439 				ti_parent_buff++;
1440 				(*no_blks_reqd)++;
1441 				debug("TICB %ld: %u\n", ti_parent_blockno,
1442 				      *total_remaining_blocks);
1443 
1444 				/* fill actual datablocks for each child */
1445 				for (k = 0; k < (fs->blksz / sizeof(int));
1446 					k++) {
1447 					actual_block_no =
1448 					    ext4fs_get_new_blk_no();
1449 					if (actual_block_no == -1) {
1450 						printf("no block left\n");
1451 						free(ti_cbuff_start_addr);
1452 						goto fail1;
1453 					}
1454 					*ti_child_buff = cpu_to_le32(actual_block_no);
1455 					debug("TIAB %ld: %u\n", actual_block_no,
1456 					      *total_remaining_blocks);
1457 
1458 					ti_child_buff++;
1459 					(*total_remaining_blocks)--;
1460 					if (*total_remaining_blocks == 0)
1461 						break;
1462 				}
1463 				/* write the child block */
1464 				put_ext4(((uint64_t) ((uint64_t)ti_child_blockno *
1465 						      (uint64_t)fs->blksz)),
1466 					 ti_cbuff_start_addr, fs->blksz);
1467 				free(ti_cbuff_start_addr);
1468 
1469 				if (*total_remaining_blocks == 0)
1470 					break;
1471 			}
1472 			/* write the parent block */
1473 			put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)),
1474 				 ti_pbuff_start_addr, fs->blksz);
1475 			free(ti_pbuff_start_addr);
1476 
1477 			if (*total_remaining_blocks == 0)
1478 				break;
1479 		}
1480 		/* write the grand parent block */
1481 		put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)),
1482 			 ti_gp_buff_start_addr, fs->blksz);
1483 		file_inode->b.blocks.triple_indir_block = cpu_to_le32(ti_gp_blockno);
1484 		free(ti_gp_buff_start_addr);
1485 		return;
1486 	}
1487 fail1:
1488 	free(ti_pbuff_start_addr);
1489 fail:
1490 	free(ti_gp_buff_start_addr);
1491 }
1492 
ext4fs_allocate_blocks(struct ext2_inode * file_inode,unsigned int total_remaining_blocks,unsigned int * total_no_of_block)1493 void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
1494 				unsigned int total_remaining_blocks,
1495 				unsigned int *total_no_of_block)
1496 {
1497 	short i;
1498 	long int direct_blockno;
1499 	unsigned int no_blks_reqd = 0;
1500 
1501 	/* allocation of direct blocks */
1502 	for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) {
1503 		direct_blockno = ext4fs_get_new_blk_no();
1504 		if (direct_blockno == -1) {
1505 			printf("no block left to assign\n");
1506 			return;
1507 		}
1508 		file_inode->b.blocks.dir_blocks[i] = cpu_to_le32(direct_blockno);
1509 		debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);
1510 
1511 		total_remaining_blocks--;
1512 	}
1513 
1514 	alloc_single_indirect_block(file_inode, &total_remaining_blocks,
1515 				    &no_blks_reqd);
1516 	alloc_double_indirect_block(file_inode, &total_remaining_blocks,
1517 				    &no_blks_reqd);
1518 	alloc_triple_indirect_block(file_inode, &total_remaining_blocks,
1519 				    &no_blks_reqd);
1520 	*total_no_of_block += no_blks_reqd;
1521 }
1522 
1523 #endif
1524 
ext4fs_get_extent_block(struct ext2_data * data,struct ext_block_cache * cache,struct ext4_extent_header * ext_block,uint32_t fileblock,int log2_blksz)1525 static struct ext4_extent_header *ext4fs_get_extent_block
1526 	(struct ext2_data *data, struct ext_block_cache *cache,
1527 		struct ext4_extent_header *ext_block,
1528 		uint32_t fileblock, int log2_blksz)
1529 {
1530 	struct ext4_extent_idx *index;
1531 	unsigned long long block;
1532 	int blksz = EXT2_BLOCK_SIZE(data);
1533 	int i;
1534 
1535 	while (1) {
1536 		index = (struct ext4_extent_idx *)(ext_block + 1);
1537 
1538 		if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
1539 			return NULL;
1540 
1541 		if (ext_block->eh_depth == 0)
1542 			return ext_block;
1543 		i = -1;
1544 		do {
1545 			i++;
1546 			if (i >= le16_to_cpu(ext_block->eh_entries))
1547 				break;
1548 		} while (fileblock >= le32_to_cpu(index[i].ei_block));
1549 
1550 		/*
1551 		 * If first logical block number is higher than requested fileblock,
1552 		 * it is a sparse file. This is handled on upper layer.
1553 		 */
1554 		if (i > 0)
1555 			i--;
1556 
1557 		block = le16_to_cpu(index[i].ei_leaf_hi);
1558 		block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
1559 		block <<= log2_blksz;
1560 		if (!ext_cache_read(cache, (lbaint_t)block, blksz))
1561 			return NULL;
1562 		ext_block = (struct ext4_extent_header *)cache->buf;
1563 	}
1564 }
1565 
ext4fs_blockgroup(struct ext2_data * data,int group,struct ext2_block_group * blkgrp)1566 static int ext4fs_blockgroup
1567 	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
1568 {
1569 	long int blkno;
1570 	unsigned int blkoff, desc_per_blk;
1571 	int log2blksz = get_fs()->dev_desc->log2blksz;
1572 	int desc_size = get_fs()->gdsize;
1573 
1574 	if (desc_size == 0)
1575 		return 0;
1576 	desc_per_blk = EXT2_BLOCK_SIZE(data) / desc_size;
1577 
1578 	if (desc_per_blk == 0)
1579 		return 0;
1580 	blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
1581 			group / desc_per_blk;
1582 	blkoff = (group % desc_per_blk) * desc_size;
1583 
1584 	debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
1585 	      group, blkno, blkoff);
1586 
1587 	return ext4fs_devread((lbaint_t)blkno <<
1588 			      (LOG2_BLOCK_SIZE(data) - log2blksz),
1589 			      blkoff, desc_size, (char *)blkgrp);
1590 }
1591 
ext4fs_read_inode(struct ext2_data * data,int ino,struct ext2_inode * inode)1592 int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
1593 {
1594 	struct ext2_block_group *blkgrp;
1595 	struct ext2_sblock *sblock = &data->sblock;
1596 	struct ext_filesystem *fs = get_fs();
1597 	int log2blksz = get_fs()->dev_desc->log2blksz;
1598 	int inodes_per_block, status;
1599 	long int blkno;
1600 	unsigned int blkoff;
1601 
1602 	/* Allocate blkgrp based on gdsize (for 64-bit support). */
1603 	blkgrp = zalloc(get_fs()->gdsize);
1604 	if (!blkgrp)
1605 		return 0;
1606 
1607 	/* It is easier to calculate if the first inode is 0. */
1608 	ino--;
1609 	if ( le32_to_cpu(sblock->inodes_per_group) == 0 || fs->inodesz == 0) {
1610 		free(blkgrp);
1611 		return 0;
1612 	}
1613 	status = ext4fs_blockgroup(data, ino / le32_to_cpu
1614 				   (sblock->inodes_per_group), blkgrp);
1615 	if (status == 0) {
1616 		free(blkgrp);
1617 		return 0;
1618 	}
1619 
1620 	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
1621 	if ( inodes_per_block == 0 ) {
1622 		free(blkgrp);
1623 		return 0;
1624 	}
1625 	blkno = ext4fs_bg_get_inode_table_id(blkgrp, fs) +
1626 	    (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1627 	blkoff = (ino % inodes_per_block) * fs->inodesz;
1628 
1629 	/* Free blkgrp as it is no longer required. */
1630 	free(blkgrp);
1631 
1632 	/* Read the inode. */
1633 	status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) -
1634 				log2blksz), blkoff,
1635 				sizeof(struct ext2_inode), (char *)inode);
1636 	if (status == 0)
1637 		return 0;
1638 
1639 	return 1;
1640 }
1641 
read_allocated_block(struct ext2_inode * inode,int fileblock,struct ext_block_cache * cache)1642 long int read_allocated_block(struct ext2_inode *inode, int fileblock,
1643 			      struct ext_block_cache *cache)
1644 {
1645 	long int blknr;
1646 	int blksz;
1647 	int log2_blksz;
1648 	int status;
1649 	long int rblock;
1650 	long int perblock_parent;
1651 	long int perblock_child;
1652 	unsigned long long start;
1653 	/* get the blocksize of the filesystem */
1654 	blksz = EXT2_BLOCK_SIZE(ext4fs_root);
1655 	log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
1656 		- get_fs()->dev_desc->log2blksz;
1657 
1658 	if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
1659 		long int startblock, endblock;
1660 		struct ext_block_cache *c, cd;
1661 		struct ext4_extent_header *ext_block;
1662 		struct ext4_extent *extent;
1663 		int i;
1664 
1665 		if (cache) {
1666 			c = cache;
1667 		} else {
1668 			c = &cd;
1669 			ext_cache_init(c);
1670 		}
1671 		ext_block =
1672 			ext4fs_get_extent_block(ext4fs_root, c,
1673 						(struct ext4_extent_header *)
1674 						inode->b.blocks.dir_blocks,
1675 						fileblock, log2_blksz);
1676 		if (!ext_block) {
1677 			printf("invalid extent block\n");
1678 			if (!cache)
1679 				ext_cache_fini(c);
1680 			return -EINVAL;
1681 		}
1682 
1683 		extent = (struct ext4_extent *)(ext_block + 1);
1684 
1685 		for (i = 0; i < le16_to_cpu(ext_block->eh_entries); i++) {
1686 			startblock = le32_to_cpu(extent[i].ee_block);
1687 			endblock = startblock + le16_to_cpu(extent[i].ee_len);
1688 
1689 			if (startblock > fileblock) {
1690 				/* Sparse file */
1691 				if (!cache)
1692 					ext_cache_fini(c);
1693 				return 0;
1694 
1695 			} else if (fileblock < endblock) {
1696 				start = le16_to_cpu(extent[i].ee_start_hi);
1697 				start = (start << 32) +
1698 					le32_to_cpu(extent[i].ee_start_lo);
1699 				if (!cache)
1700 					ext_cache_fini(c);
1701 				return (fileblock - startblock) + start;
1702 			}
1703 		}
1704 
1705 		if (!cache)
1706 			ext_cache_fini(c);
1707 		return 0;
1708 	}
1709 
1710 	/* Direct blocks. */
1711 	if (fileblock < INDIRECT_BLOCKS)
1712 		blknr = le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
1713 
1714 	/* Indirect. */
1715 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
1716 		if (ext4fs_indir1_block == NULL) {
1717 			ext4fs_indir1_block = zalloc(blksz);
1718 			if (ext4fs_indir1_block == NULL) {
1719 				printf("** SI ext2fs read block (indir 1)"
1720 					"malloc failed. **\n");
1721 				return -1;
1722 			}
1723 			ext4fs_indir1_size = blksz;
1724 			ext4fs_indir1_blkno = -1;
1725 		}
1726 		if (blksz != ext4fs_indir1_size) {
1727 			free(ext4fs_indir1_block);
1728 			ext4fs_indir1_block = NULL;
1729 			ext4fs_indir1_size = 0;
1730 			ext4fs_indir1_blkno = -1;
1731 			ext4fs_indir1_block = zalloc(blksz);
1732 			if (ext4fs_indir1_block == NULL) {
1733 				printf("** SI ext2fs read block (indir 1):"
1734 					"malloc failed. **\n");
1735 				return -1;
1736 			}
1737 			ext4fs_indir1_size = blksz;
1738 		}
1739 		if ((le32_to_cpu(inode->b.blocks.indir_block) <<
1740 		     log2_blksz) != ext4fs_indir1_blkno) {
1741 			status =
1742 			    ext4fs_devread((lbaint_t)le32_to_cpu
1743 					   (inode->b.blocks.
1744 					    indir_block) << log2_blksz, 0,
1745 					   blksz, (char *)ext4fs_indir1_block);
1746 			if (status == 0) {
1747 				printf("** SI ext2fs read block (indir 1)"
1748 					"failed. **\n");
1749 				return -1;
1750 			}
1751 			ext4fs_indir1_blkno =
1752 				le32_to_cpu(inode->b.blocks.
1753 					       indir_block) << log2_blksz;
1754 		}
1755 		blknr = le32_to_cpu(ext4fs_indir1_block
1756 				      [fileblock - INDIRECT_BLOCKS]);
1757 	}
1758 	/* Double indirect. */
1759 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
1760 					(blksz / 4 + 1)))) {
1761 
1762 		long int perblock = blksz / 4;
1763 		long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
1764 
1765 		if (ext4fs_indir1_block == NULL) {
1766 			ext4fs_indir1_block = zalloc(blksz);
1767 			if (ext4fs_indir1_block == NULL) {
1768 				printf("** DI ext2fs read block (indir 2 1)"
1769 					"malloc failed. **\n");
1770 				return -1;
1771 			}
1772 			ext4fs_indir1_size = blksz;
1773 			ext4fs_indir1_blkno = -1;
1774 		}
1775 		if (blksz != ext4fs_indir1_size) {
1776 			free(ext4fs_indir1_block);
1777 			ext4fs_indir1_block = NULL;
1778 			ext4fs_indir1_size = 0;
1779 			ext4fs_indir1_blkno = -1;
1780 			ext4fs_indir1_block = zalloc(blksz);
1781 			if (ext4fs_indir1_block == NULL) {
1782 				printf("** DI ext2fs read block (indir 2 1)"
1783 					"malloc failed. **\n");
1784 				return -1;
1785 			}
1786 			ext4fs_indir1_size = blksz;
1787 		}
1788 		if ((le32_to_cpu(inode->b.blocks.double_indir_block) <<
1789 		     log2_blksz) != ext4fs_indir1_blkno) {
1790 			status =
1791 			    ext4fs_devread((lbaint_t)le32_to_cpu
1792 					   (inode->b.blocks.
1793 					    double_indir_block) << log2_blksz,
1794 					   0, blksz,
1795 					   (char *)ext4fs_indir1_block);
1796 			if (status == 0) {
1797 				printf("** DI ext2fs read block (indir 2 1)"
1798 					"failed. **\n");
1799 				return -1;
1800 			}
1801 			ext4fs_indir1_blkno =
1802 			    le32_to_cpu(inode->b.blocks.double_indir_block) <<
1803 			    log2_blksz;
1804 		}
1805 
1806 		if (ext4fs_indir2_block == NULL) {
1807 			ext4fs_indir2_block = zalloc(blksz);
1808 			if (ext4fs_indir2_block == NULL) {
1809 				printf("** DI ext2fs read block (indir 2 2)"
1810 					"malloc failed. **\n");
1811 				return -1;
1812 			}
1813 			ext4fs_indir2_size = blksz;
1814 			ext4fs_indir2_blkno = -1;
1815 		}
1816 		if (blksz != ext4fs_indir2_size) {
1817 			free(ext4fs_indir2_block);
1818 			ext4fs_indir2_block = NULL;
1819 			ext4fs_indir2_size = 0;
1820 			ext4fs_indir2_blkno = -1;
1821 			ext4fs_indir2_block = zalloc(blksz);
1822 			if (ext4fs_indir2_block == NULL) {
1823 				printf("** DI ext2fs read block (indir 2 2)"
1824 					"malloc failed. **\n");
1825 				return -1;
1826 			}
1827 			ext4fs_indir2_size = blksz;
1828 		}
1829 		if ((le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
1830 		     log2_blksz) != ext4fs_indir2_blkno) {
1831 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1832 						(ext4fs_indir1_block
1833 						 [rblock /
1834 						  perblock]) << log2_blksz, 0,
1835 						blksz,
1836 						(char *)ext4fs_indir2_block);
1837 			if (status == 0) {
1838 				printf("** DI ext2fs read block (indir 2 2)"
1839 					"failed. **\n");
1840 				return -1;
1841 			}
1842 			ext4fs_indir2_blkno =
1843 			    le32_to_cpu(ext4fs_indir1_block[rblock
1844 							      /
1845 							      perblock]) <<
1846 			    log2_blksz;
1847 		}
1848 		blknr = le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
1849 	}
1850 	/* Tripple indirect. */
1851 	else {
1852 		rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
1853 				      (blksz / 4 * blksz / 4));
1854 		perblock_child = blksz / 4;
1855 		perblock_parent = ((blksz / 4) * (blksz / 4));
1856 
1857 		if (ext4fs_indir1_block == NULL) {
1858 			ext4fs_indir1_block = zalloc(blksz);
1859 			if (ext4fs_indir1_block == NULL) {
1860 				printf("** TI ext2fs read block (indir 2 1)"
1861 					"malloc failed. **\n");
1862 				return -1;
1863 			}
1864 			ext4fs_indir1_size = blksz;
1865 			ext4fs_indir1_blkno = -1;
1866 		}
1867 		if (blksz != ext4fs_indir1_size) {
1868 			free(ext4fs_indir1_block);
1869 			ext4fs_indir1_block = NULL;
1870 			ext4fs_indir1_size = 0;
1871 			ext4fs_indir1_blkno = -1;
1872 			ext4fs_indir1_block = zalloc(blksz);
1873 			if (ext4fs_indir1_block == NULL) {
1874 				printf("** TI ext2fs read block (indir 2 1)"
1875 					"malloc failed. **\n");
1876 				return -1;
1877 			}
1878 			ext4fs_indir1_size = blksz;
1879 		}
1880 		if ((le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1881 		     log2_blksz) != ext4fs_indir1_blkno) {
1882 			status = ext4fs_devread
1883 			    ((lbaint_t)
1884 			     le32_to_cpu(inode->b.blocks.triple_indir_block)
1885 			     << log2_blksz, 0, blksz,
1886 			     (char *)ext4fs_indir1_block);
1887 			if (status == 0) {
1888 				printf("** TI ext2fs read block (indir 2 1)"
1889 					"failed. **\n");
1890 				return -1;
1891 			}
1892 			ext4fs_indir1_blkno =
1893 			    le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1894 			    log2_blksz;
1895 		}
1896 
1897 		if (ext4fs_indir2_block == NULL) {
1898 			ext4fs_indir2_block = zalloc(blksz);
1899 			if (ext4fs_indir2_block == NULL) {
1900 				printf("** TI ext2fs read block (indir 2 2)"
1901 					"malloc failed. **\n");
1902 				return -1;
1903 			}
1904 			ext4fs_indir2_size = blksz;
1905 			ext4fs_indir2_blkno = -1;
1906 		}
1907 		if (blksz != ext4fs_indir2_size) {
1908 			free(ext4fs_indir2_block);
1909 			ext4fs_indir2_block = NULL;
1910 			ext4fs_indir2_size = 0;
1911 			ext4fs_indir2_blkno = -1;
1912 			ext4fs_indir2_block = zalloc(blksz);
1913 			if (ext4fs_indir2_block == NULL) {
1914 				printf("** TI ext2fs read block (indir 2 2)"
1915 					"malloc failed. **\n");
1916 				return -1;
1917 			}
1918 			ext4fs_indir2_size = blksz;
1919 		}
1920 		if ((le32_to_cpu(ext4fs_indir1_block[rblock /
1921 						       perblock_parent]) <<
1922 		     log2_blksz)
1923 		    != ext4fs_indir2_blkno) {
1924 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1925 						(ext4fs_indir1_block
1926 						 [rblock /
1927 						  perblock_parent]) <<
1928 						log2_blksz, 0, blksz,
1929 						(char *)ext4fs_indir2_block);
1930 			if (status == 0) {
1931 				printf("** TI ext2fs read block (indir 2 2)"
1932 					"failed. **\n");
1933 				return -1;
1934 			}
1935 			ext4fs_indir2_blkno =
1936 			    le32_to_cpu(ext4fs_indir1_block[rblock /
1937 							      perblock_parent])
1938 			    << log2_blksz;
1939 		}
1940 
1941 		if (ext4fs_indir3_block == NULL) {
1942 			ext4fs_indir3_block = zalloc(blksz);
1943 			if (ext4fs_indir3_block == NULL) {
1944 				printf("** TI ext2fs read block (indir 2 2)"
1945 					"malloc failed. **\n");
1946 				return -1;
1947 			}
1948 			ext4fs_indir3_size = blksz;
1949 			ext4fs_indir3_blkno = -1;
1950 		}
1951 		if (blksz != ext4fs_indir3_size) {
1952 			free(ext4fs_indir3_block);
1953 			ext4fs_indir3_block = NULL;
1954 			ext4fs_indir3_size = 0;
1955 			ext4fs_indir3_blkno = -1;
1956 			ext4fs_indir3_block = zalloc(blksz);
1957 			if (ext4fs_indir3_block == NULL) {
1958 				printf("** TI ext2fs read block (indir 2 2)"
1959 					"malloc failed. **\n");
1960 				return -1;
1961 			}
1962 			ext4fs_indir3_size = blksz;
1963 		}
1964 		if ((le32_to_cpu(ext4fs_indir2_block[rblock
1965 						       /
1966 						       perblock_child]) <<
1967 		     log2_blksz) != ext4fs_indir3_blkno) {
1968 			status =
1969 			    ext4fs_devread((lbaint_t)le32_to_cpu
1970 					   (ext4fs_indir2_block
1971 					    [(rblock / perblock_child)
1972 					     % (blksz / 4)]) << log2_blksz, 0,
1973 					   blksz, (char *)ext4fs_indir3_block);
1974 			if (status == 0) {
1975 				printf("** TI ext2fs read block (indir 2 2)"
1976 				       "failed. **\n");
1977 				return -1;
1978 			}
1979 			ext4fs_indir3_blkno =
1980 			    le32_to_cpu(ext4fs_indir2_block[(rblock /
1981 							       perblock_child) %
1982 							      (blksz /
1983 							       4)]) <<
1984 			    log2_blksz;
1985 		}
1986 
1987 		blknr = le32_to_cpu(ext4fs_indir3_block
1988 				      [rblock % perblock_child]);
1989 	}
1990 	debug("read_allocated_block %ld\n", blknr);
1991 
1992 	return blknr;
1993 }
1994 
1995 /**
1996  * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's
1997  *			    global pointers
1998  *
1999  * This function assures that for a file with the same name but different size
2000  * the sequential store on the ext4 filesystem will be correct.
2001  *
2002  * In this function the global data, responsible for internal representation
2003  * of the ext4 data are initialized to the reset state. Without this, during
2004  * replacement of the smaller file with the bigger truncation of new file was
2005  * performed.
2006  */
ext4fs_reinit_global(void)2007 void ext4fs_reinit_global(void)
2008 {
2009 	if (ext4fs_indir1_block != NULL) {
2010 		free(ext4fs_indir1_block);
2011 		ext4fs_indir1_block = NULL;
2012 		ext4fs_indir1_size = 0;
2013 		ext4fs_indir1_blkno = -1;
2014 	}
2015 	if (ext4fs_indir2_block != NULL) {
2016 		free(ext4fs_indir2_block);
2017 		ext4fs_indir2_block = NULL;
2018 		ext4fs_indir2_size = 0;
2019 		ext4fs_indir2_blkno = -1;
2020 	}
2021 	if (ext4fs_indir3_block != NULL) {
2022 		free(ext4fs_indir3_block);
2023 		ext4fs_indir3_block = NULL;
2024 		ext4fs_indir3_size = 0;
2025 		ext4fs_indir3_blkno = -1;
2026 	}
2027 }
ext4fs_close(void)2028 void ext4fs_close(void)
2029 {
2030 	if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
2031 		ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
2032 		ext4fs_file = NULL;
2033 	}
2034 	if (ext4fs_root != NULL) {
2035 		free(ext4fs_root);
2036 		ext4fs_root = NULL;
2037 	}
2038 
2039 	ext4fs_reinit_global();
2040 }
2041 
ext4fs_iterate_dir(struct ext2fs_node * dir,char * name,struct ext2fs_node ** fnode,int * ftype)2042 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
2043 				struct ext2fs_node **fnode, int *ftype)
2044 {
2045 	unsigned int fpos = 0;
2046 	int status;
2047 	loff_t actread;
2048 	struct ext2fs_node *diro = (struct ext2fs_node *) dir;
2049 
2050 #ifdef DEBUG
2051 	if (name != NULL)
2052 		printf("Iterate dir %s\n", name);
2053 #endif /* of DEBUG */
2054 	if (!diro->inode_read) {
2055 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2056 		if (status == 0)
2057 			return 0;
2058 	}
2059 	/* Search the file.  */
2060 	while (fpos < le32_to_cpu(diro->inode.size)) {
2061 		struct ext2_dirent dirent;
2062 
2063 		status = ext4fs_read_file(diro, fpos,
2064 					   sizeof(struct ext2_dirent),
2065 					   (char *)&dirent, &actread);
2066 		if (status < 0)
2067 			return 0;
2068 
2069 		if (dirent.direntlen == 0) {
2070 			printf("Failed to iterate over directory %s\n", name);
2071 			return 0;
2072 		}
2073 
2074 		if (dirent.namelen != 0) {
2075 			char filename[dirent.namelen + 1];
2076 			struct ext2fs_node *fdiro;
2077 			int type = FILETYPE_UNKNOWN;
2078 
2079 			status = ext4fs_read_file(diro,
2080 						  fpos +
2081 						  sizeof(struct ext2_dirent),
2082 						  dirent.namelen, filename,
2083 						  &actread);
2084 			if (status < 0)
2085 				return 0;
2086 
2087 			fdiro = zalloc(sizeof(struct ext2fs_node));
2088 			if (!fdiro)
2089 				return 0;
2090 
2091 			fdiro->data = diro->data;
2092 			fdiro->ino = le32_to_cpu(dirent.inode);
2093 
2094 			filename[dirent.namelen] = '\0';
2095 
2096 			if (dirent.filetype != FILETYPE_UNKNOWN) {
2097 				fdiro->inode_read = 0;
2098 
2099 				if (dirent.filetype == FILETYPE_DIRECTORY)
2100 					type = FILETYPE_DIRECTORY;
2101 				else if (dirent.filetype == FILETYPE_SYMLINK)
2102 					type = FILETYPE_SYMLINK;
2103 				else if (dirent.filetype == FILETYPE_REG)
2104 					type = FILETYPE_REG;
2105 			} else {
2106 				status = ext4fs_read_inode(diro->data,
2107 							   le32_to_cpu
2108 							   (dirent.inode),
2109 							   &fdiro->inode);
2110 				if (status == 0) {
2111 					free(fdiro);
2112 					return 0;
2113 				}
2114 				fdiro->inode_read = 1;
2115 
2116 				if ((le16_to_cpu(fdiro->inode.mode) &
2117 				     FILETYPE_INO_MASK) ==
2118 				    FILETYPE_INO_DIRECTORY) {
2119 					type = FILETYPE_DIRECTORY;
2120 				} else if ((le16_to_cpu(fdiro->inode.mode)
2121 					    & FILETYPE_INO_MASK) ==
2122 					   FILETYPE_INO_SYMLINK) {
2123 					type = FILETYPE_SYMLINK;
2124 				} else if ((le16_to_cpu(fdiro->inode.mode)
2125 					    & FILETYPE_INO_MASK) ==
2126 					   FILETYPE_INO_REG) {
2127 					type = FILETYPE_REG;
2128 				}
2129 			}
2130 #ifdef DEBUG
2131 			printf("iterate >%s<\n", filename);
2132 #endif /* of DEBUG */
2133 			if ((name != NULL) && (fnode != NULL)
2134 			    && (ftype != NULL)) {
2135 				if (strcmp(filename, name) == 0) {
2136 					*ftype = type;
2137 					*fnode = fdiro;
2138 					return 1;
2139 				}
2140 			} else {
2141 				if (fdiro->inode_read == 0) {
2142 					status = ext4fs_read_inode(diro->data,
2143 								 le32_to_cpu(
2144 								 dirent.inode),
2145 								 &fdiro->inode);
2146 					if (status == 0) {
2147 						free(fdiro);
2148 						return 0;
2149 					}
2150 					fdiro->inode_read = 1;
2151 				}
2152 				switch (type) {
2153 				case FILETYPE_DIRECTORY:
2154 					printf("<DIR> ");
2155 					break;
2156 				case FILETYPE_SYMLINK:
2157 					printf("<SYM> ");
2158 					break;
2159 				case FILETYPE_REG:
2160 					printf("      ");
2161 					break;
2162 				default:
2163 					printf("< ? > ");
2164 					break;
2165 				}
2166 				printf("%10u %s\n",
2167 				       le32_to_cpu(fdiro->inode.size),
2168 					filename);
2169 			}
2170 			free(fdiro);
2171 		}
2172 		fpos += le16_to_cpu(dirent.direntlen);
2173 	}
2174 	return 0;
2175 }
2176 
ext4fs_read_symlink(struct ext2fs_node * node)2177 static char *ext4fs_read_symlink(struct ext2fs_node *node)
2178 {
2179 	char *symlink;
2180 	struct ext2fs_node *diro = node;
2181 	int status;
2182 	loff_t actread;
2183 
2184 	if (!diro->inode_read) {
2185 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2186 		if (status == 0)
2187 			return NULL;
2188 	}
2189 	symlink = zalloc(le32_to_cpu(diro->inode.size) + 1);
2190 	if (!symlink)
2191 		return NULL;
2192 
2193 	if (le32_to_cpu(diro->inode.size) < sizeof(diro->inode.b.symlink)) {
2194 		strncpy(symlink, diro->inode.b.symlink,
2195 			 le32_to_cpu(diro->inode.size));
2196 	} else {
2197 		status = ext4fs_read_file(diro, 0,
2198 					   le32_to_cpu(diro->inode.size),
2199 					   symlink, &actread);
2200 		if ((status < 0) || (actread == 0)) {
2201 			free(symlink);
2202 			return NULL;
2203 		}
2204 	}
2205 	symlink[le32_to_cpu(diro->inode.size)] = '\0';
2206 	return symlink;
2207 }
2208 
ext4fs_find_file1(const char * currpath,struct ext2fs_node * currroot,struct ext2fs_node ** currfound,int * foundtype)2209 static int ext4fs_find_file1(const char *currpath,
2210 			     struct ext2fs_node *currroot,
2211 			     struct ext2fs_node **currfound, int *foundtype)
2212 {
2213 	char fpath[strlen(currpath) + 1];
2214 	char *name = fpath;
2215 	char *next;
2216 	int status;
2217 	int type = FILETYPE_DIRECTORY;
2218 	struct ext2fs_node *currnode = currroot;
2219 	struct ext2fs_node *oldnode = currroot;
2220 
2221 	strncpy(fpath, currpath, strlen(currpath) + 1);
2222 
2223 	/* Remove all leading slashes. */
2224 	while (*name == '/')
2225 		name++;
2226 
2227 	if (!*name) {
2228 		*currfound = currnode;
2229 		return 1;
2230 	}
2231 
2232 	for (;;) {
2233 		int found;
2234 
2235 		/* Extract the actual part from the pathname. */
2236 		next = strchr(name, '/');
2237 		if (next) {
2238 			/* Remove all leading slashes. */
2239 			while (*next == '/')
2240 				*(next++) = '\0';
2241 		}
2242 
2243 		if (type != FILETYPE_DIRECTORY) {
2244 			ext4fs_free_node(currnode, currroot);
2245 			return 0;
2246 		}
2247 
2248 		oldnode = currnode;
2249 
2250 		/* Iterate over the directory. */
2251 		found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
2252 		if (found == 0)
2253 			return 0;
2254 
2255 		if (found == -1)
2256 			break;
2257 
2258 		/* Read in the symlink and follow it. */
2259 		if (type == FILETYPE_SYMLINK) {
2260 			char *symlink;
2261 
2262 			/* Test if the symlink does not loop. */
2263 			if (++symlinknest == 8) {
2264 				ext4fs_free_node(currnode, currroot);
2265 				ext4fs_free_node(oldnode, currroot);
2266 				return 0;
2267 			}
2268 
2269 			symlink = ext4fs_read_symlink(currnode);
2270 			ext4fs_free_node(currnode, currroot);
2271 
2272 			if (!symlink) {
2273 				ext4fs_free_node(oldnode, currroot);
2274 				return 0;
2275 			}
2276 
2277 			debug("Got symlink >%s<\n", symlink);
2278 
2279 			if (symlink[0] == '/') {
2280 				ext4fs_free_node(oldnode, currroot);
2281 				oldnode = &ext4fs_root->diropen;
2282 			}
2283 
2284 			/* Lookup the node the symlink points to. */
2285 			status = ext4fs_find_file1(symlink, oldnode,
2286 						    &currnode, &type);
2287 
2288 			free(symlink);
2289 
2290 			if (status == 0) {
2291 				ext4fs_free_node(oldnode, currroot);
2292 				return 0;
2293 			}
2294 		}
2295 
2296 		ext4fs_free_node(oldnode, currroot);
2297 
2298 		/* Found the node! */
2299 		if (!next || *next == '\0') {
2300 			*currfound = currnode;
2301 			*foundtype = type;
2302 			return 1;
2303 		}
2304 		name = next;
2305 	}
2306 	return -1;
2307 }
2308 
ext4fs_find_file(const char * path,struct ext2fs_node * rootnode,struct ext2fs_node ** foundnode,int expecttype)2309 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
2310 	struct ext2fs_node **foundnode, int expecttype)
2311 {
2312 	int status;
2313 	int foundtype = FILETYPE_DIRECTORY;
2314 
2315 	symlinknest = 0;
2316 	if (!path)
2317 		return 0;
2318 
2319 	status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
2320 	if (status == 0)
2321 		return 0;
2322 
2323 	/* Check if the node that was found was of the expected type. */
2324 	if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
2325 		return 0;
2326 	else if ((expecttype == FILETYPE_DIRECTORY)
2327 		   && (foundtype != expecttype))
2328 		return 0;
2329 
2330 	return 1;
2331 }
2332 
ext4fs_open(const char * filename,loff_t * len)2333 int ext4fs_open(const char *filename, loff_t *len)
2334 {
2335 	struct ext2fs_node *fdiro = NULL;
2336 	int status;
2337 
2338 	if (ext4fs_root == NULL)
2339 		return -1;
2340 
2341 	ext4fs_file = NULL;
2342 	status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
2343 				  FILETYPE_REG);
2344 	if (status == 0)
2345 		goto fail;
2346 
2347 	if (!fdiro->inode_read) {
2348 		status = ext4fs_read_inode(fdiro->data, fdiro->ino,
2349 				&fdiro->inode);
2350 		if (status == 0)
2351 			goto fail;
2352 	}
2353 	*len = le32_to_cpu(fdiro->inode.size);
2354 	ext4fs_file = fdiro;
2355 
2356 	return 0;
2357 fail:
2358 	ext4fs_free_node(fdiro, &ext4fs_root->diropen);
2359 
2360 	return -1;
2361 }
2362 
ext4fs_mount(unsigned part_length)2363 int ext4fs_mount(unsigned part_length)
2364 {
2365 	struct ext2_data *data;
2366 	int status;
2367 	struct ext_filesystem *fs = get_fs();
2368 	data = zalloc(SUPERBLOCK_SIZE);
2369 	if (!data)
2370 		return 0;
2371 
2372 	/* Read the superblock. */
2373 	status = ext4_read_superblock((char *)&data->sblock);
2374 
2375 	if (status == 0)
2376 		goto fail;
2377 
2378 	/* Make sure this is an ext2 filesystem. */
2379 	if (le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
2380 		goto fail_noerr;
2381 
2382 
2383 	if (le32_to_cpu(data->sblock.revision_level) == 0) {
2384 		fs->inodesz = 128;
2385 		fs->gdsize = 32;
2386 	} else {
2387 		debug("EXT4 features COMPAT: %08x INCOMPAT: %08x RO_COMPAT: %08x\n",
2388 		      __le32_to_cpu(data->sblock.feature_compatibility),
2389 		      __le32_to_cpu(data->sblock.feature_incompat),
2390 		      __le32_to_cpu(data->sblock.feature_ro_compat));
2391 
2392 		fs->inodesz = le16_to_cpu(data->sblock.inode_size);
2393 		fs->gdsize = le32_to_cpu(data->sblock.feature_incompat) &
2394 			EXT4_FEATURE_INCOMPAT_64BIT ?
2395 			le16_to_cpu(data->sblock.descriptor_size) : 32;
2396 	}
2397 
2398 	debug("EXT2 rev %d, inode_size %d, descriptor size %d\n",
2399 	      le32_to_cpu(data->sblock.revision_level),
2400 	      fs->inodesz, fs->gdsize);
2401 
2402 	data->diropen.data = data;
2403 	data->diropen.ino = 2;
2404 	data->diropen.inode_read = 1;
2405 	data->inode = &data->diropen.inode;
2406 
2407 	status = ext4fs_read_inode(data, 2, data->inode);
2408 	if (status == 0)
2409 		goto fail;
2410 
2411 	ext4fs_root = data;
2412 
2413 	return 1;
2414 fail:
2415 	printf("Failed to mount ext2 filesystem...\n");
2416 fail_noerr:
2417 	free(data);
2418 	ext4fs_root = NULL;
2419 
2420 	return 0;
2421 }
2422