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 <blk.h>
23 #include <ext_common.h>
24 #include <ext4fs.h>
25 #include <log.h>
26 #include <malloc.h>
27 #include <memalign.h>
28 #include <part.h>
29 #include <stddef.h>
30 #include <linux/stat.h>
31 #include <linux/time.h>
32 #include <asm/byteorder.h>
33 #include "ext4_common.h"
34 
35 struct ext2_data *ext4fs_root;
36 struct ext2fs_node *ext4fs_file;
37 __le32 *ext4fs_indir1_block;
38 int ext4fs_indir1_size;
39 int ext4fs_indir1_blkno = -1;
40 __le32 *ext4fs_indir2_block;
41 int ext4fs_indir2_size;
42 int ext4fs_indir2_blkno = -1;
43 
44 __le32 *ext4fs_indir3_block;
45 int ext4fs_indir3_size;
46 int ext4fs_indir3_blkno = -1;
47 struct ext2_inode *g_parent_inode;
48 static int symlinknest;
49 
50 #if defined(CONFIG_EXT4_WRITE)
ext4fs_get_group_descriptor(const struct ext_filesystem * fs,uint32_t bg_idx)51 struct ext2_block_group *ext4fs_get_group_descriptor
52 	(const struct ext_filesystem *fs, uint32_t bg_idx)
53 {
54 	return (struct ext2_block_group *)(fs->gdtable + (bg_idx * fs->gdsize));
55 }
56 
ext4fs_sb_free_inodes_dec(struct ext2_sblock * sb)57 static inline void ext4fs_sb_free_inodes_dec(struct ext2_sblock *sb)
58 {
59 	sb->free_inodes = cpu_to_le32(le32_to_cpu(sb->free_inodes) - 1);
60 }
61 
ext4fs_sb_free_blocks_dec(struct ext2_sblock * sb)62 static inline void ext4fs_sb_free_blocks_dec(struct ext2_sblock *sb)
63 {
64 	uint64_t free_blocks = le32_to_cpu(sb->free_blocks);
65 	free_blocks += (uint64_t)le32_to_cpu(sb->free_blocks_high) << 32;
66 	free_blocks--;
67 
68 	sb->free_blocks = cpu_to_le32(free_blocks & 0xffffffff);
69 	sb->free_blocks_high = cpu_to_le16(free_blocks >> 32);
70 }
71 
ext4fs_bg_free_inodes_dec(struct ext2_block_group * bg,const struct ext_filesystem * fs)72 static inline void ext4fs_bg_free_inodes_dec
73 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
74 {
75 	uint32_t free_inodes = le16_to_cpu(bg->free_inodes);
76 	if (fs->gdsize == 64)
77 		free_inodes += le16_to_cpu(bg->free_inodes_high) << 16;
78 	free_inodes--;
79 
80 	bg->free_inodes = cpu_to_le16(free_inodes & 0xffff);
81 	if (fs->gdsize == 64)
82 		bg->free_inodes_high = cpu_to_le16(free_inodes >> 16);
83 }
84 
ext4fs_bg_free_blocks_dec(struct ext2_block_group * bg,const struct ext_filesystem * fs)85 static inline void ext4fs_bg_free_blocks_dec
86 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
87 {
88 	uint32_t free_blocks = le16_to_cpu(bg->free_blocks);
89 	if (fs->gdsize == 64)
90 		free_blocks += le16_to_cpu(bg->free_blocks_high) << 16;
91 	free_blocks--;
92 
93 	bg->free_blocks = cpu_to_le16(free_blocks & 0xffff);
94 	if (fs->gdsize == 64)
95 		bg->free_blocks_high = cpu_to_le16(free_blocks >> 16);
96 }
97 
ext4fs_bg_itable_unused_dec(struct ext2_block_group * bg,const struct ext_filesystem * fs)98 static inline void ext4fs_bg_itable_unused_dec
99 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
100 {
101 	uint32_t free_inodes = le16_to_cpu(bg->bg_itable_unused);
102 	if (fs->gdsize == 64)
103 		free_inodes += le16_to_cpu(bg->bg_itable_unused_high) << 16;
104 	free_inodes--;
105 
106 	bg->bg_itable_unused = cpu_to_le16(free_inodes & 0xffff);
107 	if (fs->gdsize == 64)
108 		bg->bg_itable_unused_high = cpu_to_le16(free_inodes >> 16);
109 }
110 
ext4fs_sb_get_free_blocks(const struct ext2_sblock * sb)111 uint64_t ext4fs_sb_get_free_blocks(const struct ext2_sblock *sb)
112 {
113 	uint64_t free_blocks = le32_to_cpu(sb->free_blocks);
114 	free_blocks += (uint64_t)le32_to_cpu(sb->free_blocks_high) << 32;
115 	return free_blocks;
116 }
117 
ext4fs_sb_set_free_blocks(struct ext2_sblock * sb,uint64_t free_blocks)118 void ext4fs_sb_set_free_blocks(struct ext2_sblock *sb, uint64_t free_blocks)
119 {
120 	sb->free_blocks = cpu_to_le32(free_blocks & 0xffffffff);
121 	sb->free_blocks_high = cpu_to_le16(free_blocks >> 32);
122 }
123 
ext4fs_bg_get_free_blocks(const struct ext2_block_group * bg,const struct ext_filesystem * fs)124 uint32_t ext4fs_bg_get_free_blocks(const struct ext2_block_group *bg,
125 				   const struct ext_filesystem *fs)
126 {
127 	uint32_t free_blocks = le16_to_cpu(bg->free_blocks);
128 	if (fs->gdsize == 64)
129 		free_blocks += le16_to_cpu(bg->free_blocks_high) << 16;
130 	return free_blocks;
131 }
132 
133 static inline
ext4fs_bg_get_free_inodes(const struct ext2_block_group * bg,const struct ext_filesystem * fs)134 uint32_t ext4fs_bg_get_free_inodes(const struct ext2_block_group *bg,
135 				   const struct ext_filesystem *fs)
136 {
137 	uint32_t free_inodes = le16_to_cpu(bg->free_inodes);
138 	if (fs->gdsize == 64)
139 		free_inodes += le16_to_cpu(bg->free_inodes_high) << 16;
140 	return free_inodes;
141 }
142 
ext4fs_bg_get_flags(const struct ext2_block_group * bg)143 static inline uint16_t ext4fs_bg_get_flags(const struct ext2_block_group *bg)
144 {
145 	return le16_to_cpu(bg->bg_flags);
146 }
147 
ext4fs_bg_set_flags(struct ext2_block_group * bg,uint16_t flags)148 static inline void ext4fs_bg_set_flags(struct ext2_block_group *bg,
149 				       uint16_t flags)
150 {
151 	bg->bg_flags = cpu_to_le16(flags);
152 }
153 
154 /* Block number of the block bitmap */
ext4fs_bg_get_block_id(const struct ext2_block_group * bg,const struct ext_filesystem * fs)155 uint64_t ext4fs_bg_get_block_id(const struct ext2_block_group *bg,
156 				const struct ext_filesystem *fs)
157 {
158 	uint64_t block_nr = le32_to_cpu(bg->block_id);
159 	if (fs->gdsize == 64)
160 		block_nr += (uint64_t)le32_to_cpu(bg->block_id_high) << 32;
161 	return block_nr;
162 }
163 
164 /* Block number of the inode bitmap */
ext4fs_bg_get_inode_id(const struct ext2_block_group * bg,const struct ext_filesystem * fs)165 uint64_t ext4fs_bg_get_inode_id(const struct ext2_block_group *bg,
166 				const struct ext_filesystem *fs)
167 {
168 	uint64_t block_nr = le32_to_cpu(bg->inode_id);
169 	if (fs->gdsize == 64)
170 		block_nr += (uint64_t)le32_to_cpu(bg->inode_id_high) << 32;
171 	return block_nr;
172 }
173 #endif
174 
175 /* Block number of the inode table */
ext4fs_bg_get_inode_table_id(const struct ext2_block_group * bg,const struct ext_filesystem * fs)176 uint64_t ext4fs_bg_get_inode_table_id(const struct ext2_block_group *bg,
177 				      const struct ext_filesystem *fs)
178 {
179 	uint64_t block_nr = le32_to_cpu(bg->inode_table_id);
180 	if (fs->gdsize == 64)
181 		block_nr +=
182 			(uint64_t)le32_to_cpu(bg->inode_table_id_high) << 32;
183 	return block_nr;
184 }
185 
186 #if defined(CONFIG_EXT4_WRITE)
ext4fs_div_roundup(uint32_t size,uint32_t n)187 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n)
188 {
189 	uint32_t res = size / n;
190 	if (res * n != size)
191 		res++;
192 
193 	return res;
194 }
195 
put_ext4(uint64_t off,const void * buf,uint32_t size)196 void put_ext4(uint64_t off, const void *buf, uint32_t size)
197 {
198 	uint64_t startblock;
199 	uint64_t remainder;
200 	unsigned char *temp_ptr = NULL;
201 	struct ext_filesystem *fs = get_fs();
202 	int log2blksz = fs->dev_desc->log2blksz;
203 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, sec_buf, fs->dev_desc->blksz);
204 
205 	startblock = off >> log2blksz;
206 	startblock += part_offset;
207 	remainder = off & (uint64_t)(fs->dev_desc->blksz - 1);
208 
209 	if (fs->dev_desc == NULL)
210 		return;
211 
212 	if ((startblock + (size >> log2blksz)) >
213 	    (part_offset + fs->total_sect)) {
214 		printf("part_offset is " LBAFU "\n", part_offset);
215 		printf("total_sector is %llu\n", fs->total_sect);
216 		printf("error: overflow occurs\n");
217 		return;
218 	}
219 
220 	if (remainder) {
221 		blk_dread(fs->dev_desc, startblock, 1, sec_buf);
222 		temp_ptr = sec_buf;
223 		memcpy((temp_ptr + remainder), (unsigned char *)buf, size);
224 		blk_dwrite(fs->dev_desc, startblock, 1, sec_buf);
225 	} else {
226 		if (size >> log2blksz != 0) {
227 			blk_dwrite(fs->dev_desc, startblock, size >> log2blksz,
228 				   (unsigned long *)buf);
229 		} else {
230 			blk_dread(fs->dev_desc, startblock, 1, sec_buf);
231 			temp_ptr = sec_buf;
232 			memcpy(temp_ptr, buf, size);
233 			blk_dwrite(fs->dev_desc, startblock, 1,
234 				   (unsigned long *)sec_buf);
235 		}
236 	}
237 }
238 
_get_new_inode_no(unsigned char * buffer)239 static int _get_new_inode_no(unsigned char *buffer)
240 {
241 	struct ext_filesystem *fs = get_fs();
242 	unsigned char input;
243 	int operand, status;
244 	int count = 1;
245 	int j = 0;
246 
247 	/* get the blocksize of the filesystem */
248 	unsigned char *ptr = buffer;
249 	while (*ptr == 255) {
250 		ptr++;
251 		count += 8;
252 		if (count > le32_to_cpu(ext4fs_root->sblock.inodes_per_group))
253 			return -1;
254 	}
255 
256 	for (j = 0; j < fs->blksz; j++) {
257 		input = *ptr;
258 		int i = 0;
259 		while (i <= 7) {
260 			operand = 1 << i;
261 			status = input & operand;
262 			if (status) {
263 				i++;
264 				count++;
265 			} else {
266 				*ptr |= operand;
267 				return count;
268 			}
269 		}
270 		ptr = ptr + 1;
271 	}
272 
273 	return -1;
274 }
275 
_get_new_blk_no(unsigned char * buffer)276 static int _get_new_blk_no(unsigned char *buffer)
277 {
278 	int operand;
279 	int count = 0;
280 	int i;
281 	unsigned char *ptr = buffer;
282 	struct ext_filesystem *fs = get_fs();
283 
284 	while (*ptr == 255) {
285 		ptr++;
286 		count += 8;
287 		if (count == (fs->blksz * 8))
288 			return -1;
289 	}
290 
291 	if (fs->blksz == 1024)
292 		count += 1;
293 
294 	for (i = 0; i <= 7; i++) {
295 		operand = 1 << i;
296 		if (*ptr & operand) {
297 			count++;
298 		} else {
299 			*ptr |= operand;
300 			return count;
301 		}
302 	}
303 
304 	return -1;
305 }
306 
ext4fs_set_block_bmap(long int blockno,unsigned char * buffer,int index)307 int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index)
308 {
309 	int i, remainder, status;
310 	unsigned char *ptr = buffer;
311 	unsigned char operand;
312 	i = blockno / 8;
313 	remainder = blockno % 8;
314 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
315 
316 	i = i - (index * blocksize);
317 	if (blocksize != 1024) {
318 		ptr = ptr + i;
319 		operand = 1 << remainder;
320 		status = *ptr & operand;
321 		if (status)
322 			return -1;
323 
324 		*ptr = *ptr | operand;
325 		return 0;
326 	} else {
327 		if (remainder == 0) {
328 			ptr = ptr + i - 1;
329 			operand = (1 << 7);
330 		} else {
331 			ptr = ptr + i;
332 			operand = (1 << (remainder - 1));
333 		}
334 		status = *ptr & operand;
335 		if (status)
336 			return -1;
337 
338 		*ptr = *ptr | operand;
339 		return 0;
340 	}
341 }
342 
ext4fs_reset_block_bmap(long int blockno,unsigned char * buffer,int index)343 void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index)
344 {
345 	int i, remainder, status;
346 	unsigned char *ptr = buffer;
347 	unsigned char operand;
348 	i = blockno / 8;
349 	remainder = blockno % 8;
350 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
351 
352 	i = i - (index * blocksize);
353 	if (blocksize != 1024) {
354 		ptr = ptr + i;
355 		operand = (1 << remainder);
356 		status = *ptr & operand;
357 		if (status)
358 			*ptr = *ptr & ~(operand);
359 	} else {
360 		if (remainder == 0) {
361 			ptr = ptr + i - 1;
362 			operand = (1 << 7);
363 		} else {
364 			ptr = ptr + i;
365 			operand = (1 << (remainder - 1));
366 		}
367 		status = *ptr & operand;
368 		if (status)
369 			*ptr = *ptr & ~(operand);
370 	}
371 }
372 
ext4fs_set_inode_bmap(int inode_no,unsigned char * buffer,int index)373 int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index)
374 {
375 	int i, remainder, status;
376 	unsigned char *ptr = buffer;
377 	unsigned char operand;
378 
379 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
380 	i = inode_no / 8;
381 	remainder = inode_no % 8;
382 	if (remainder == 0) {
383 		ptr = ptr + i - 1;
384 		operand = (1 << 7);
385 	} else {
386 		ptr = ptr + i;
387 		operand = (1 << (remainder - 1));
388 	}
389 	status = *ptr & operand;
390 	if (status)
391 		return -1;
392 
393 	*ptr = *ptr | operand;
394 
395 	return 0;
396 }
397 
ext4fs_reset_inode_bmap(int inode_no,unsigned char * buffer,int index)398 void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index)
399 {
400 	int i, remainder, status;
401 	unsigned char *ptr = buffer;
402 	unsigned char operand;
403 
404 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
405 	i = inode_no / 8;
406 	remainder = inode_no % 8;
407 	if (remainder == 0) {
408 		ptr = ptr + i - 1;
409 		operand = (1 << 7);
410 	} else {
411 		ptr = ptr + i;
412 		operand = (1 << (remainder - 1));
413 	}
414 	status = *ptr & operand;
415 	if (status)
416 		*ptr = *ptr & ~(operand);
417 }
418 
ext4fs_checksum_update(uint32_t i)419 uint16_t ext4fs_checksum_update(uint32_t i)
420 {
421 	struct ext2_block_group *desc;
422 	struct ext_filesystem *fs = get_fs();
423 	uint16_t crc = 0;
424 	__le32 le32_i = cpu_to_le32(i);
425 
426 	desc = ext4fs_get_group_descriptor(fs, i);
427 	if (le32_to_cpu(fs->sb->feature_ro_compat) & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
428 		int offset = offsetof(struct ext2_block_group, bg_checksum);
429 
430 		crc = ext2fs_crc16(~0, fs->sb->unique_id,
431 				   sizeof(fs->sb->unique_id));
432 		crc = ext2fs_crc16(crc, &le32_i, sizeof(le32_i));
433 		crc = ext2fs_crc16(crc, desc, offset);
434 		offset += sizeof(desc->bg_checksum);	/* skip checksum */
435 		assert(offset == sizeof(*desc));
436 		if (offset < fs->gdsize) {
437 			crc = ext2fs_crc16(crc, (__u8 *)desc + offset,
438 					   fs->gdsize - offset);
439 		}
440 	}
441 
442 	return crc;
443 }
444 
check_void_in_dentry(struct ext2_dirent * dir,char * filename)445 static int check_void_in_dentry(struct ext2_dirent *dir, char *filename)
446 {
447 	int dentry_length;
448 	int sizeof_void_space;
449 	int new_entry_byte_reqd;
450 	short padding_factor = 0;
451 
452 	if (dir->namelen % 4 != 0)
453 		padding_factor = 4 - (dir->namelen % 4);
454 
455 	dentry_length = sizeof(struct ext2_dirent) +
456 			dir->namelen + padding_factor;
457 	sizeof_void_space = le16_to_cpu(dir->direntlen) - dentry_length;
458 	if (sizeof_void_space == 0)
459 		return 0;
460 
461 	padding_factor = 0;
462 	if (strlen(filename) % 4 != 0)
463 		padding_factor = 4 - (strlen(filename) % 4);
464 
465 	new_entry_byte_reqd = strlen(filename) +
466 	    sizeof(struct ext2_dirent) + padding_factor;
467 	if (sizeof_void_space >= new_entry_byte_reqd) {
468 		dir->direntlen = cpu_to_le16(dentry_length);
469 		return sizeof_void_space;
470 	}
471 
472 	return 0;
473 }
474 
ext4fs_update_parent_dentry(char * filename,int file_type)475 int ext4fs_update_parent_dentry(char *filename, int file_type)
476 {
477 	unsigned int *zero_buffer = NULL;
478 	char *root_first_block_buffer = NULL;
479 	int blk_idx;
480 	long int first_block_no_of_root = 0;
481 	int totalbytes = 0;
482 	unsigned int new_entry_byte_reqd;
483 	int sizeof_void_space = 0;
484 	int templength = 0;
485 	int inodeno = -1;
486 	int status;
487 	struct ext_filesystem *fs = get_fs();
488 	/* directory entry */
489 	struct ext2_dirent *dir;
490 	char *temp_dir = NULL;
491 	uint32_t new_blk_no;
492 	uint32_t new_size;
493 	uint32_t new_blockcnt;
494 	uint32_t directory_blocks;
495 
496 	zero_buffer = zalloc(fs->blksz);
497 	if (!zero_buffer) {
498 		printf("No Memory\n");
499 		return -1;
500 	}
501 	root_first_block_buffer = zalloc(fs->blksz);
502 	if (!root_first_block_buffer) {
503 		free(zero_buffer);
504 		printf("No Memory\n");
505 		return -1;
506 	}
507 	new_entry_byte_reqd = ROUND(strlen(filename) +
508 				    sizeof(struct ext2_dirent), 4);
509 restart:
510 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
511 		LOG2_BLOCK_SIZE(ext4fs_root);
512 	blk_idx = directory_blocks - 1;
513 
514 restart_read:
515 	/* read the block no allocated to a file */
516 	first_block_no_of_root = read_allocated_block(g_parent_inode, blk_idx,
517 						      NULL);
518 	if (first_block_no_of_root <= 0)
519 		goto fail;
520 
521 	status = ext4fs_devread((lbaint_t)first_block_no_of_root
522 				* fs->sect_perblk,
523 				0, fs->blksz, root_first_block_buffer);
524 	if (status == 0)
525 		goto fail;
526 
527 	if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
528 		goto fail;
529 	dir = (struct ext2_dirent *)root_first_block_buffer;
530 	totalbytes = 0;
531 
532 	while (le16_to_cpu(dir->direntlen) > 0) {
533 		unsigned short used_len = ROUND(dir->namelen +
534 		    sizeof(struct ext2_dirent), 4);
535 
536 		/* last entry of block */
537 		if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen)) {
538 
539 			/* check if new entry fits */
540 			if ((used_len + new_entry_byte_reqd) <=
541 			    le16_to_cpu(dir->direntlen)) {
542 				dir->direntlen = cpu_to_le16(used_len);
543 				break;
544 			} else {
545 				if (blk_idx > 0) {
546 					printf("Block full, trying previous\n");
547 					blk_idx--;
548 					goto restart_read;
549 				}
550 				printf("All blocks full: Allocate new\n");
551 
552 				if (le32_to_cpu(g_parent_inode->flags) &
553 						EXT4_EXTENTS_FL) {
554 					printf("Directory uses extents\n");
555 					goto fail;
556 				}
557 				if (directory_blocks >= INDIRECT_BLOCKS) {
558 					printf("Directory exceeds limit\n");
559 					goto fail;
560 				}
561 				new_blk_no = ext4fs_get_new_blk_no();
562 				if (new_blk_no == -1) {
563 					printf("no block left to assign\n");
564 					goto fail;
565 				}
566 				put_ext4((uint64_t)new_blk_no * fs->blksz, zero_buffer, fs->blksz);
567 				g_parent_inode->b.blocks.
568 					dir_blocks[directory_blocks] =
569 					cpu_to_le32(new_blk_no);
570 
571 				new_size = le32_to_cpu(g_parent_inode->size);
572 				new_size += fs->blksz;
573 				g_parent_inode->size = cpu_to_le32(new_size);
574 
575 				new_blockcnt = le32_to_cpu(g_parent_inode->blockcnt);
576 				new_blockcnt += fs->blksz >> LOG2_SECTOR_SIZE;
577 				g_parent_inode->blockcnt = cpu_to_le32(new_blockcnt);
578 
579 				if (ext4fs_put_metadata
580 				    (root_first_block_buffer,
581 				     first_block_no_of_root))
582 					goto fail;
583 				goto restart;
584 			}
585 		}
586 
587 		templength = le16_to_cpu(dir->direntlen);
588 		totalbytes = totalbytes + templength;
589 		sizeof_void_space = check_void_in_dentry(dir, filename);
590 		if (sizeof_void_space)
591 			break;
592 
593 		dir = (struct ext2_dirent *)((char *)dir + templength);
594 	}
595 
596 	/* make a pointer ready for creating next directory entry */
597 	templength = le16_to_cpu(dir->direntlen);
598 	totalbytes = totalbytes + templength;
599 	dir = (struct ext2_dirent *)((char *)dir + templength);
600 
601 	/* get the next available inode number */
602 	inodeno = ext4fs_get_new_inode_no();
603 	if (inodeno == -1) {
604 		printf("no inode left to assign\n");
605 		goto fail;
606 	}
607 	dir->inode = cpu_to_le32(inodeno);
608 	if (sizeof_void_space)
609 		dir->direntlen = cpu_to_le16(sizeof_void_space);
610 	else
611 		dir->direntlen = cpu_to_le16(fs->blksz - totalbytes);
612 
613 	dir->namelen = strlen(filename);
614 	dir->filetype = file_type;
615 	temp_dir = (char *)dir;
616 	temp_dir = temp_dir + sizeof(struct ext2_dirent);
617 	memcpy(temp_dir, filename, strlen(filename));
618 
619 	/* update or write  the 1st block of root inode */
620 	if (ext4fs_put_metadata(root_first_block_buffer,
621 				first_block_no_of_root))
622 		goto fail;
623 
624 fail:
625 	free(zero_buffer);
626 	free(root_first_block_buffer);
627 
628 	return inodeno;
629 }
630 
search_dir(struct ext2_inode * parent_inode,char * dirname)631 static int search_dir(struct ext2_inode *parent_inode, char *dirname)
632 {
633 	int status;
634 	int inodeno = 0;
635 	int offset;
636 	int blk_idx;
637 	long int blknr;
638 	char *block_buffer = NULL;
639 	struct ext2_dirent *dir = NULL;
640 	struct ext_filesystem *fs = get_fs();
641 	uint32_t directory_blocks;
642 	char *direntname;
643 
644 	directory_blocks = le32_to_cpu(parent_inode->size) >>
645 		LOG2_BLOCK_SIZE(ext4fs_root);
646 
647 	block_buffer = zalloc(fs->blksz);
648 	if (!block_buffer)
649 		goto fail;
650 
651 	/* get the block no allocated to a file */
652 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
653 		blknr = read_allocated_block(parent_inode, blk_idx, NULL);
654 		if (blknr <= 0)
655 			goto fail;
656 
657 		/* read the directory block */
658 		status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk,
659 					0, fs->blksz, (char *)block_buffer);
660 		if (status == 0)
661 			goto fail;
662 
663 		offset = 0;
664 		do {
665 			if (offset & 3) {
666 				printf("Badly aligned ext2_dirent\n");
667 				break;
668 			}
669 
670 			dir = (struct ext2_dirent *)(block_buffer + offset);
671 			direntname = (char*)(dir) + sizeof(struct ext2_dirent);
672 
673 			int direntlen = le16_to_cpu(dir->direntlen);
674 			if (direntlen < sizeof(struct ext2_dirent))
675 				break;
676 
677 			if (dir->inode && (strlen(dirname) == dir->namelen) &&
678 			    (strncmp(dirname, direntname, dir->namelen) == 0)) {
679 				inodeno = le32_to_cpu(dir->inode);
680 				break;
681 			}
682 
683 			offset += direntlen;
684 
685 		} while (offset < fs->blksz);
686 
687 		if (inodeno > 0) {
688 			free(block_buffer);
689 			return inodeno;
690 		}
691 	}
692 
693 fail:
694 	free(block_buffer);
695 
696 	return -1;
697 }
698 
find_dir_depth(char * dirname)699 static int find_dir_depth(char *dirname)
700 {
701 	char *token = strtok(dirname, "/");
702 	int count = 0;
703 	while (token != NULL) {
704 		token = strtok(NULL, "/");
705 		count++;
706 	}
707 	return count + 1 + 1;
708 	/*
709 	 * for example  for string /home/temp
710 	 * depth=home(1)+temp(1)+1 extra for NULL;
711 	 * so count is 4;
712 	 */
713 }
714 
parse_path(char ** arr,char * dirname)715 static int parse_path(char **arr, char *dirname)
716 {
717 	char *token = strtok(dirname, "/");
718 	int i = 0;
719 
720 	/* add root */
721 	arr[i] = zalloc(strlen("/") + 1);
722 	if (!arr[i])
723 		return -ENOMEM;
724 	memcpy(arr[i++], "/", strlen("/"));
725 
726 	/* add each path entry after root */
727 	while (token != NULL) {
728 		arr[i] = zalloc(strlen(token) + 1);
729 		if (!arr[i])
730 			return -ENOMEM;
731 		memcpy(arr[i++], token, strlen(token));
732 		token = strtok(NULL, "/");
733 	}
734 	arr[i] = NULL;
735 
736 	return 0;
737 }
738 
ext4fs_iget(int inode_no,struct ext2_inode * inode)739 int ext4fs_iget(int inode_no, struct ext2_inode *inode)
740 {
741 	if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0)
742 		return -1;
743 
744 	return 0;
745 }
746 
747 /*
748  * Function: ext4fs_get_parent_inode_num
749  * Return Value: inode Number of the parent directory of  file/Directory to be
750  * created
751  * dirname : Input parmater, input path name of the file/directory to be created
752  * dname : Output parameter, to be filled with the name of the directory
753  * extracted from dirname
754  */
ext4fs_get_parent_inode_num(const char * dirname,char * dname,int flags)755 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags)
756 {
757 	int i;
758 	int depth = 0;
759 	int matched_inode_no;
760 	int result_inode_no = -1;
761 	char **ptr = NULL;
762 	char *depth_dirname = NULL;
763 	char *parse_dirname = NULL;
764 	struct ext2_inode *parent_inode = NULL;
765 	struct ext2_inode *first_inode = NULL;
766 	struct ext2_inode temp_inode;
767 
768 	if (*dirname != '/') {
769 		printf("Please supply Absolute path\n");
770 		return -1;
771 	}
772 
773 	/* TODO: input validation make equivalent to linux */
774 	depth_dirname = zalloc(strlen(dirname) + 1);
775 	if (!depth_dirname)
776 		return -ENOMEM;
777 
778 	memcpy(depth_dirname, dirname, strlen(dirname));
779 	depth = find_dir_depth(depth_dirname);
780 	parse_dirname = zalloc(strlen(dirname) + 1);
781 	if (!parse_dirname)
782 		goto fail;
783 	memcpy(parse_dirname, dirname, strlen(dirname));
784 
785 	/* allocate memory for each directory level */
786 	ptr = zalloc((depth) * sizeof(char *));
787 	if (!ptr)
788 		goto fail;
789 	if (parse_path(ptr, parse_dirname))
790 		goto fail;
791 	parent_inode = zalloc(sizeof(struct ext2_inode));
792 	if (!parent_inode)
793 		goto fail;
794 	first_inode = zalloc(sizeof(struct ext2_inode));
795 	if (!first_inode)
796 		goto fail;
797 	memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode));
798 	memcpy(first_inode, parent_inode, sizeof(struct ext2_inode));
799 	if (flags & F_FILE)
800 		result_inode_no = EXT2_ROOT_INO;
801 	for (i = 1; i < depth; i++) {
802 		matched_inode_no = search_dir(parent_inode, ptr[i]);
803 		if (matched_inode_no == -1) {
804 			if (ptr[i + 1] == NULL && i == 1) {
805 				result_inode_no = EXT2_ROOT_INO;
806 				goto end;
807 			} else {
808 				if (ptr[i + 1] == NULL)
809 					break;
810 				printf("Invalid path\n");
811 				result_inode_no = -1;
812 				goto fail;
813 			}
814 		} else {
815 			if (ptr[i + 1] != NULL) {
816 				memset(parent_inode, '\0',
817 				       sizeof(struct ext2_inode));
818 				if (ext4fs_iget(matched_inode_no,
819 						parent_inode)) {
820 					result_inode_no = -1;
821 					goto fail;
822 				}
823 				result_inode_no = matched_inode_no;
824 			} else {
825 				break;
826 			}
827 		}
828 	}
829 
830 end:
831 	if (i == 1)
832 		matched_inode_no = search_dir(first_inode, ptr[i]);
833 	else
834 		matched_inode_no = search_dir(parent_inode, ptr[i]);
835 
836 	if (matched_inode_no != -1) {
837 		ext4fs_iget(matched_inode_no, &temp_inode);
838 		if (le16_to_cpu(temp_inode.mode) & S_IFDIR) {
839 			printf("It is a Directory\n");
840 			result_inode_no = -1;
841 			goto fail;
842 		}
843 	}
844 
845 	if (strlen(ptr[i]) > 256) {
846 		result_inode_no = -1;
847 		goto fail;
848 	}
849 	memcpy(dname, ptr[i], strlen(ptr[i]));
850 
851 fail:
852 	free(depth_dirname);
853 	free(parse_dirname);
854 	for (i = 0; i < depth; i++) {
855 		if (!ptr[i])
856 			break;
857 		free(ptr[i]);
858 	}
859 	free(ptr);
860 	free(parent_inode);
861 	free(first_inode);
862 
863 	return result_inode_no;
864 }
865 
unlink_filename(char * filename,unsigned int blknr)866 static int unlink_filename(char *filename, unsigned int blknr)
867 {
868 	int status;
869 	int inodeno = 0;
870 	int offset;
871 	char *block_buffer = NULL;
872 	struct ext2_dirent *dir = NULL;
873 	struct ext2_dirent *previous_dir;
874 	struct ext_filesystem *fs = get_fs();
875 	int ret = -1;
876 	char *direntname;
877 
878 	block_buffer = zalloc(fs->blksz);
879 	if (!block_buffer)
880 		return -ENOMEM;
881 
882 	/* read the directory block */
883 	status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0,
884 				fs->blksz, block_buffer);
885 	if (status == 0)
886 		goto fail;
887 
888 	offset = 0;
889 	do {
890 		if (offset & 3) {
891 			printf("Badly aligned ext2_dirent\n");
892 			break;
893 		}
894 
895 		previous_dir = dir;
896 		dir = (struct ext2_dirent *)(block_buffer + offset);
897 		direntname = (char *)(dir) + sizeof(struct ext2_dirent);
898 
899 		int direntlen = le16_to_cpu(dir->direntlen);
900 		if (direntlen < sizeof(struct ext2_dirent))
901 			break;
902 
903 		if (dir->inode && (strlen(filename) == dir->namelen) &&
904 		    (strncmp(direntname, filename, dir->namelen) == 0)) {
905 			inodeno = le32_to_cpu(dir->inode);
906 			break;
907 		}
908 
909 		offset += direntlen;
910 
911 	} while (offset < fs->blksz);
912 
913 	if (inodeno > 0) {
914 		printf("file found, deleting\n");
915 		if (ext4fs_log_journal(block_buffer, blknr))
916 			goto fail;
917 
918 		if (previous_dir) {
919 			/* merge dir entry with predecessor */
920 			uint16_t new_len;
921 			new_len = le16_to_cpu(previous_dir->direntlen);
922 			new_len += le16_to_cpu(dir->direntlen);
923 			previous_dir->direntlen = cpu_to_le16(new_len);
924 		} else {
925 			/* invalidate dir entry */
926 			dir->inode = 0;
927 		}
928 		if (ext4fs_put_metadata(block_buffer, blknr))
929 			goto fail;
930 		ret = inodeno;
931 	}
932 fail:
933 	free(block_buffer);
934 
935 	return ret;
936 }
937 
ext4fs_filename_unlink(char * filename)938 int ext4fs_filename_unlink(char *filename)
939 {
940 	int blk_idx;
941 	long int blknr = -1;
942 	int inodeno = -1;
943 	uint32_t directory_blocks;
944 
945 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
946 		LOG2_BLOCK_SIZE(ext4fs_root);
947 
948 	/* read the block no allocated to a file */
949 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
950 		blknr = read_allocated_block(g_parent_inode, blk_idx, NULL);
951 		if (blknr <= 0)
952 			break;
953 		inodeno = unlink_filename(filename, blknr);
954 		if (inodeno != -1)
955 			return inodeno;
956 	}
957 
958 	return -1;
959 }
960 
ext4fs_get_new_blk_no(void)961 uint32_t ext4fs_get_new_blk_no(void)
962 {
963 	short i;
964 	short status;
965 	int remainder;
966 	unsigned int bg_idx;
967 	static int prev_bg_bitmap_index = -1;
968 	unsigned int blk_per_grp = le32_to_cpu(ext4fs_root->sblock.blocks_per_group);
969 	struct ext_filesystem *fs = get_fs();
970 	char *journal_buffer = zalloc(fs->blksz);
971 	char *zero_buffer = zalloc(fs->blksz);
972 	if (!journal_buffer || !zero_buffer)
973 		goto fail;
974 
975 	if (fs->first_pass_bbmap == 0) {
976 		for (i = 0; i < fs->no_blkgrp; i++) {
977 			struct ext2_block_group *bgd = NULL;
978 			bgd = ext4fs_get_group_descriptor(fs, i);
979 			if (ext4fs_bg_get_free_blocks(bgd, fs)) {
980 				uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
981 				uint64_t b_bitmap_blk =
982 					ext4fs_bg_get_block_id(bgd, fs);
983 				if (bg_flags & EXT4_BG_BLOCK_UNINIT) {
984 					memcpy(fs->blk_bmaps[i], zero_buffer,
985 					       fs->blksz);
986 					put_ext4(b_bitmap_blk * fs->blksz,
987 						 fs->blk_bmaps[i], fs->blksz);
988 					bg_flags &= ~EXT4_BG_BLOCK_UNINIT;
989 					ext4fs_bg_set_flags(bgd, bg_flags);
990 				}
991 				fs->curr_blkno =
992 				    _get_new_blk_no(fs->blk_bmaps[i]);
993 				if (fs->curr_blkno == -1)
994 					/* block bitmap is completely filled */
995 					continue;
996 				fs->curr_blkno = fs->curr_blkno +
997 						(i * fs->blksz * 8);
998 				fs->first_pass_bbmap++;
999 				ext4fs_bg_free_blocks_dec(bgd, fs);
1000 				ext4fs_sb_free_blocks_dec(fs->sb);
1001 				status = ext4fs_devread(b_bitmap_blk *
1002 							fs->sect_perblk,
1003 							0, fs->blksz,
1004 							journal_buffer);
1005 				if (status == 0)
1006 					goto fail;
1007 				if (ext4fs_log_journal(journal_buffer,
1008 						       b_bitmap_blk))
1009 					goto fail;
1010 				goto success;
1011 			} else {
1012 				debug("no space left on block group %d\n", i);
1013 			}
1014 		}
1015 
1016 		goto fail;
1017 	} else {
1018 		fs->curr_blkno++;
1019 restart:
1020 		/* get the blockbitmap index respective to blockno */
1021 		bg_idx = fs->curr_blkno / blk_per_grp;
1022 		if (fs->blksz == 1024) {
1023 			remainder = fs->curr_blkno % blk_per_grp;
1024 			if (!remainder)
1025 				bg_idx--;
1026 		}
1027 
1028 		/*
1029 		 * To skip completely filled block group bitmaps
1030 		 * Optimize the block allocation
1031 		 */
1032 		if (bg_idx >= fs->no_blkgrp)
1033 			goto fail;
1034 
1035 		struct ext2_block_group *bgd = NULL;
1036 		bgd = ext4fs_get_group_descriptor(fs, bg_idx);
1037 		if (ext4fs_bg_get_free_blocks(bgd, fs) == 0) {
1038 			debug("block group %u is full. Skipping\n", bg_idx);
1039 			fs->curr_blkno = (bg_idx + 1) * blk_per_grp;
1040 			if (fs->blksz == 1024)
1041 				fs->curr_blkno += 1;
1042 			goto restart;
1043 		}
1044 
1045 		uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1046 		uint64_t b_bitmap_blk = ext4fs_bg_get_block_id(bgd, fs);
1047 		if (bg_flags & EXT4_BG_BLOCK_UNINIT) {
1048 			memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz);
1049 			put_ext4(b_bitmap_blk * fs->blksz,
1050 				 zero_buffer, fs->blksz);
1051 			bg_flags &= ~EXT4_BG_BLOCK_UNINIT;
1052 			ext4fs_bg_set_flags(bgd, bg_flags);
1053 		}
1054 
1055 		if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx],
1056 				   bg_idx) != 0) {
1057 			debug("going for restart for the block no %ld %u\n",
1058 			      fs->curr_blkno, bg_idx);
1059 			fs->curr_blkno++;
1060 			goto restart;
1061 		}
1062 
1063 		/* journal backup */
1064 		if (prev_bg_bitmap_index != bg_idx) {
1065 			status = ext4fs_devread(b_bitmap_blk * fs->sect_perblk,
1066 						0, fs->blksz, journal_buffer);
1067 			if (status == 0)
1068 				goto fail;
1069 			if (ext4fs_log_journal(journal_buffer, b_bitmap_blk))
1070 				goto fail;
1071 
1072 			prev_bg_bitmap_index = bg_idx;
1073 		}
1074 		ext4fs_bg_free_blocks_dec(bgd, fs);
1075 		ext4fs_sb_free_blocks_dec(fs->sb);
1076 		goto success;
1077 	}
1078 success:
1079 	free(journal_buffer);
1080 	free(zero_buffer);
1081 
1082 	return fs->curr_blkno;
1083 fail:
1084 	free(journal_buffer);
1085 	free(zero_buffer);
1086 
1087 	return -1;
1088 }
1089 
ext4fs_get_new_inode_no(void)1090 int ext4fs_get_new_inode_no(void)
1091 {
1092 	short i;
1093 	short status;
1094 	unsigned int ibmap_idx;
1095 	static int prev_inode_bitmap_index = -1;
1096 	unsigned int inodes_per_grp = le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
1097 	struct ext_filesystem *fs = get_fs();
1098 	char *journal_buffer = zalloc(fs->blksz);
1099 	char *zero_buffer = zalloc(fs->blksz);
1100 	if (!journal_buffer || !zero_buffer)
1101 		goto fail;
1102 	int has_gdt_chksum = le32_to_cpu(fs->sb->feature_ro_compat) &
1103 		EXT4_FEATURE_RO_COMPAT_GDT_CSUM ? 1 : 0;
1104 
1105 	if (fs->first_pass_ibmap == 0) {
1106 		for (i = 0; i < fs->no_blkgrp; i++) {
1107 			uint32_t free_inodes;
1108 			struct ext2_block_group *bgd = NULL;
1109 			bgd = ext4fs_get_group_descriptor(fs, i);
1110 			free_inodes = ext4fs_bg_get_free_inodes(bgd, fs);
1111 			if (free_inodes) {
1112 				uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1113 				uint64_t i_bitmap_blk =
1114 					ext4fs_bg_get_inode_id(bgd, fs);
1115 				if (has_gdt_chksum)
1116 					bgd->bg_itable_unused = free_inodes;
1117 				if (bg_flags & EXT4_BG_INODE_UNINIT) {
1118 					put_ext4(i_bitmap_blk * fs->blksz,
1119 						 zero_buffer, fs->blksz);
1120 					bg_flags &= ~EXT4_BG_INODE_UNINIT;
1121 					ext4fs_bg_set_flags(bgd, bg_flags);
1122 					memcpy(fs->inode_bmaps[i],
1123 					       zero_buffer, fs->blksz);
1124 				}
1125 				fs->curr_inode_no =
1126 				    _get_new_inode_no(fs->inode_bmaps[i]);
1127 				if (fs->curr_inode_no == -1)
1128 					/* inode bitmap is completely filled */
1129 					continue;
1130 				fs->curr_inode_no = fs->curr_inode_no +
1131 							(i * inodes_per_grp);
1132 				fs->first_pass_ibmap++;
1133 				ext4fs_bg_free_inodes_dec(bgd, fs);
1134 				if (has_gdt_chksum)
1135 					ext4fs_bg_itable_unused_dec(bgd, fs);
1136 				ext4fs_sb_free_inodes_dec(fs->sb);
1137 				status = ext4fs_devread(i_bitmap_blk *
1138 							fs->sect_perblk,
1139 							0, fs->blksz,
1140 							journal_buffer);
1141 				if (status == 0)
1142 					goto fail;
1143 				if (ext4fs_log_journal(journal_buffer,
1144 						       i_bitmap_blk))
1145 					goto fail;
1146 				goto success;
1147 			} else
1148 				debug("no inode left on block group %d\n", i);
1149 		}
1150 		goto fail;
1151 	} else {
1152 restart:
1153 		fs->curr_inode_no++;
1154 		/* get the blockbitmap index respective to blockno */
1155 		ibmap_idx = fs->curr_inode_no / inodes_per_grp;
1156 		struct ext2_block_group *bgd =
1157 			ext4fs_get_group_descriptor(fs, ibmap_idx);
1158 		uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1159 		uint64_t i_bitmap_blk = ext4fs_bg_get_inode_id(bgd, fs);
1160 
1161 		if (bg_flags & EXT4_BG_INODE_UNINIT) {
1162 			put_ext4(i_bitmap_blk * fs->blksz,
1163 				 zero_buffer, fs->blksz);
1164 			bg_flags &= ~EXT4_BG_INODE_UNINIT;
1165 			ext4fs_bg_set_flags(bgd, bg_flags);
1166 			memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer,
1167 				fs->blksz);
1168 		}
1169 
1170 		if (ext4fs_set_inode_bmap(fs->curr_inode_no,
1171 					  fs->inode_bmaps[ibmap_idx],
1172 					  ibmap_idx) != 0) {
1173 			debug("going for restart for the block no %d %u\n",
1174 			      fs->curr_inode_no, ibmap_idx);
1175 			goto restart;
1176 		}
1177 
1178 		/* journal backup */
1179 		if (prev_inode_bitmap_index != ibmap_idx) {
1180 			status = ext4fs_devread(i_bitmap_blk * fs->sect_perblk,
1181 						0, fs->blksz, journal_buffer);
1182 			if (status == 0)
1183 				goto fail;
1184 			if (ext4fs_log_journal(journal_buffer,
1185 						le32_to_cpu(bgd->inode_id)))
1186 				goto fail;
1187 			prev_inode_bitmap_index = ibmap_idx;
1188 		}
1189 		ext4fs_bg_free_inodes_dec(bgd, fs);
1190 		if (has_gdt_chksum)
1191 			bgd->bg_itable_unused = bgd->free_inodes;
1192 		ext4fs_sb_free_inodes_dec(fs->sb);
1193 		goto success;
1194 	}
1195 
1196 success:
1197 	free(journal_buffer);
1198 	free(zero_buffer);
1199 
1200 	return fs->curr_inode_no;
1201 fail:
1202 	free(journal_buffer);
1203 	free(zero_buffer);
1204 
1205 	return -1;
1206 
1207 }
1208 
1209 
alloc_single_indirect_block(struct ext2_inode * file_inode,unsigned int * total_remaining_blocks,unsigned int * no_blks_reqd)1210 static void alloc_single_indirect_block(struct ext2_inode *file_inode,
1211 					unsigned int *total_remaining_blocks,
1212 					unsigned int *no_blks_reqd)
1213 {
1214 	short i;
1215 	short status;
1216 	long int actual_block_no;
1217 	long int si_blockno;
1218 	/* si :single indirect */
1219 	__le32 *si_buffer = NULL;
1220 	__le32 *si_start_addr = NULL;
1221 	struct ext_filesystem *fs = get_fs();
1222 
1223 	if (*total_remaining_blocks != 0) {
1224 		si_buffer = zalloc(fs->blksz);
1225 		if (!si_buffer) {
1226 			printf("No Memory\n");
1227 			return;
1228 		}
1229 		si_start_addr = si_buffer;
1230 		si_blockno = ext4fs_get_new_blk_no();
1231 		if (si_blockno == -1) {
1232 			printf("no block left to assign\n");
1233 			goto fail;
1234 		}
1235 		(*no_blks_reqd)++;
1236 		debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks);
1237 
1238 		status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk,
1239 					0, fs->blksz, (char *)si_buffer);
1240 		memset(si_buffer, '\0', fs->blksz);
1241 		if (status == 0)
1242 			goto fail;
1243 
1244 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1245 			actual_block_no = ext4fs_get_new_blk_no();
1246 			if (actual_block_no == -1) {
1247 				printf("no block left to assign\n");
1248 				goto fail;
1249 			}
1250 			*si_buffer = cpu_to_le32(actual_block_no);
1251 			debug("SIAB %u: %u\n", *si_buffer,
1252 				*total_remaining_blocks);
1253 
1254 			si_buffer++;
1255 			(*total_remaining_blocks)--;
1256 			if (*total_remaining_blocks == 0)
1257 				break;
1258 		}
1259 
1260 		/* write the block to disk */
1261 		put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)),
1262 			 si_start_addr, fs->blksz);
1263 		file_inode->b.blocks.indir_block = cpu_to_le32(si_blockno);
1264 	}
1265 fail:
1266 	free(si_start_addr);
1267 }
1268 
alloc_double_indirect_block(struct ext2_inode * file_inode,unsigned int * total_remaining_blocks,unsigned int * no_blks_reqd)1269 static void alloc_double_indirect_block(struct ext2_inode *file_inode,
1270 					unsigned int *total_remaining_blocks,
1271 					unsigned int *no_blks_reqd)
1272 {
1273 	short i;
1274 	short j;
1275 	short status;
1276 	long int actual_block_no;
1277 	/* di:double indirect */
1278 	long int di_blockno_parent;
1279 	long int di_blockno_child;
1280 	__le32 *di_parent_buffer = NULL;
1281 	__le32 *di_child_buff = NULL;
1282 	__le32 *di_block_start_addr = NULL;
1283 	__le32 *di_child_buff_start = NULL;
1284 	struct ext_filesystem *fs = get_fs();
1285 
1286 	if (*total_remaining_blocks != 0) {
1287 		/* double indirect parent block connecting to inode */
1288 		di_blockno_parent = ext4fs_get_new_blk_no();
1289 		if (di_blockno_parent == -1) {
1290 			printf("no block left to assign\n");
1291 			goto fail;
1292 		}
1293 		di_parent_buffer = zalloc(fs->blksz);
1294 		if (!di_parent_buffer)
1295 			goto fail;
1296 
1297 		di_block_start_addr = di_parent_buffer;
1298 		(*no_blks_reqd)++;
1299 		debug("DIPB %ld: %u\n", di_blockno_parent,
1300 		      *total_remaining_blocks);
1301 
1302 		status = ext4fs_devread((lbaint_t)di_blockno_parent *
1303 					fs->sect_perblk, 0,
1304 					fs->blksz, (char *)di_parent_buffer);
1305 
1306 		if (!status) {
1307 			printf("%s: Device read error!\n", __func__);
1308 			goto fail;
1309 		}
1310 		memset(di_parent_buffer, '\0', fs->blksz);
1311 
1312 		/*
1313 		 * start:for each double indirect parent
1314 		 * block create one more block
1315 		 */
1316 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1317 			di_blockno_child = ext4fs_get_new_blk_no();
1318 			if (di_blockno_child == -1) {
1319 				printf("no block left to assign\n");
1320 				goto fail;
1321 			}
1322 			di_child_buff = zalloc(fs->blksz);
1323 			if (!di_child_buff)
1324 				goto fail;
1325 
1326 			di_child_buff_start = di_child_buff;
1327 			*di_parent_buffer = cpu_to_le32(di_blockno_child);
1328 			di_parent_buffer++;
1329 			(*no_blks_reqd)++;
1330 			debug("DICB %ld: %u\n", di_blockno_child,
1331 			      *total_remaining_blocks);
1332 
1333 			status = ext4fs_devread((lbaint_t)di_blockno_child *
1334 						fs->sect_perblk, 0,
1335 						fs->blksz,
1336 						(char *)di_child_buff);
1337 
1338 			if (!status) {
1339 				printf("%s: Device read error!\n", __func__);
1340 				goto fail;
1341 			}
1342 			memset(di_child_buff, '\0', fs->blksz);
1343 			/* filling of actual datablocks for each child */
1344 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1345 				actual_block_no = ext4fs_get_new_blk_no();
1346 				if (actual_block_no == -1) {
1347 					printf("no block left to assign\n");
1348 					goto fail;
1349 				}
1350 				*di_child_buff = cpu_to_le32(actual_block_no);
1351 				debug("DIAB %ld: %u\n", actual_block_no,
1352 				      *total_remaining_blocks);
1353 
1354 				di_child_buff++;
1355 				(*total_remaining_blocks)--;
1356 				if (*total_remaining_blocks == 0)
1357 					break;
1358 			}
1359 			/* write the block  table */
1360 			put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)),
1361 				 di_child_buff_start, fs->blksz);
1362 			free(di_child_buff_start);
1363 			di_child_buff_start = NULL;
1364 
1365 			if (*total_remaining_blocks == 0)
1366 				break;
1367 		}
1368 		put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)),
1369 			 di_block_start_addr, fs->blksz);
1370 		file_inode->b.blocks.double_indir_block = cpu_to_le32(di_blockno_parent);
1371 	}
1372 fail:
1373 	free(di_block_start_addr);
1374 }
1375 
alloc_triple_indirect_block(struct ext2_inode * file_inode,unsigned int * total_remaining_blocks,unsigned int * no_blks_reqd)1376 static void alloc_triple_indirect_block(struct ext2_inode *file_inode,
1377 					unsigned int *total_remaining_blocks,
1378 					unsigned int *no_blks_reqd)
1379 {
1380 	short i;
1381 	short j;
1382 	short k;
1383 	long int actual_block_no;
1384 	/* ti: Triple Indirect */
1385 	long int ti_gp_blockno;
1386 	long int ti_parent_blockno;
1387 	long int ti_child_blockno;
1388 	__le32 *ti_gp_buff = NULL;
1389 	__le32 *ti_parent_buff = NULL;
1390 	__le32 *ti_child_buff = NULL;
1391 	__le32 *ti_gp_buff_start_addr = NULL;
1392 	__le32 *ti_pbuff_start_addr = NULL;
1393 	__le32 *ti_cbuff_start_addr = NULL;
1394 	struct ext_filesystem *fs = get_fs();
1395 	if (*total_remaining_blocks != 0) {
1396 		/* triple indirect grand parent block connecting to inode */
1397 		ti_gp_blockno = ext4fs_get_new_blk_no();
1398 		if (ti_gp_blockno == -1) {
1399 			printf("no block left to assign\n");
1400 			return;
1401 		}
1402 		ti_gp_buff = zalloc(fs->blksz);
1403 		if (!ti_gp_buff)
1404 			return;
1405 
1406 		ti_gp_buff_start_addr = ti_gp_buff;
1407 		(*no_blks_reqd)++;
1408 		debug("TIGPB %ld: %u\n", ti_gp_blockno,
1409 		      *total_remaining_blocks);
1410 
1411 		/* for each 4 byte grand parent entry create one more block */
1412 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1413 			ti_parent_blockno = ext4fs_get_new_blk_no();
1414 			if (ti_parent_blockno == -1) {
1415 				printf("no block left to assign\n");
1416 				goto fail;
1417 			}
1418 			ti_parent_buff = zalloc(fs->blksz);
1419 			if (!ti_parent_buff)
1420 				goto fail;
1421 
1422 			ti_pbuff_start_addr = ti_parent_buff;
1423 			*ti_gp_buff = cpu_to_le32(ti_parent_blockno);
1424 			ti_gp_buff++;
1425 			(*no_blks_reqd)++;
1426 			debug("TIPB %ld: %u\n", ti_parent_blockno,
1427 			      *total_remaining_blocks);
1428 
1429 			/* for each 4 byte entry parent create one more block */
1430 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1431 				ti_child_blockno = ext4fs_get_new_blk_no();
1432 				if (ti_child_blockno == -1) {
1433 					printf("no block left assign\n");
1434 					goto fail1;
1435 				}
1436 				ti_child_buff = zalloc(fs->blksz);
1437 				if (!ti_child_buff)
1438 					goto fail1;
1439 
1440 				ti_cbuff_start_addr = ti_child_buff;
1441 				*ti_parent_buff = cpu_to_le32(ti_child_blockno);
1442 				ti_parent_buff++;
1443 				(*no_blks_reqd)++;
1444 				debug("TICB %ld: %u\n", ti_parent_blockno,
1445 				      *total_remaining_blocks);
1446 
1447 				/* fill actual datablocks for each child */
1448 				for (k = 0; k < (fs->blksz / sizeof(int));
1449 					k++) {
1450 					actual_block_no =
1451 					    ext4fs_get_new_blk_no();
1452 					if (actual_block_no == -1) {
1453 						printf("no block left\n");
1454 						free(ti_cbuff_start_addr);
1455 						goto fail1;
1456 					}
1457 					*ti_child_buff = cpu_to_le32(actual_block_no);
1458 					debug("TIAB %ld: %u\n", actual_block_no,
1459 					      *total_remaining_blocks);
1460 
1461 					ti_child_buff++;
1462 					(*total_remaining_blocks)--;
1463 					if (*total_remaining_blocks == 0)
1464 						break;
1465 				}
1466 				/* write the child block */
1467 				put_ext4(((uint64_t) ((uint64_t)ti_child_blockno *
1468 						      (uint64_t)fs->blksz)),
1469 					 ti_cbuff_start_addr, fs->blksz);
1470 				free(ti_cbuff_start_addr);
1471 
1472 				if (*total_remaining_blocks == 0)
1473 					break;
1474 			}
1475 			/* write the parent block */
1476 			put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)),
1477 				 ti_pbuff_start_addr, fs->blksz);
1478 			free(ti_pbuff_start_addr);
1479 
1480 			if (*total_remaining_blocks == 0)
1481 				break;
1482 		}
1483 		/* write the grand parent block */
1484 		put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)),
1485 			 ti_gp_buff_start_addr, fs->blksz);
1486 		file_inode->b.blocks.triple_indir_block = cpu_to_le32(ti_gp_blockno);
1487 		free(ti_gp_buff_start_addr);
1488 		return;
1489 	}
1490 fail1:
1491 	free(ti_pbuff_start_addr);
1492 fail:
1493 	free(ti_gp_buff_start_addr);
1494 }
1495 
ext4fs_allocate_blocks(struct ext2_inode * file_inode,unsigned int total_remaining_blocks,unsigned int * total_no_of_block)1496 void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
1497 				unsigned int total_remaining_blocks,
1498 				unsigned int *total_no_of_block)
1499 {
1500 	short i;
1501 	long int direct_blockno;
1502 	unsigned int no_blks_reqd = 0;
1503 
1504 	/* allocation of direct blocks */
1505 	for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) {
1506 		direct_blockno = ext4fs_get_new_blk_no();
1507 		if (direct_blockno == -1) {
1508 			printf("no block left to assign\n");
1509 			return;
1510 		}
1511 		file_inode->b.blocks.dir_blocks[i] = cpu_to_le32(direct_blockno);
1512 		debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);
1513 
1514 		total_remaining_blocks--;
1515 	}
1516 
1517 	alloc_single_indirect_block(file_inode, &total_remaining_blocks,
1518 				    &no_blks_reqd);
1519 	alloc_double_indirect_block(file_inode, &total_remaining_blocks,
1520 				    &no_blks_reqd);
1521 	alloc_triple_indirect_block(file_inode, &total_remaining_blocks,
1522 				    &no_blks_reqd);
1523 	*total_no_of_block += no_blks_reqd;
1524 }
1525 
1526 #endif
1527 
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)1528 static struct ext4_extent_header *ext4fs_get_extent_block
1529 	(struct ext2_data *data, struct ext_block_cache *cache,
1530 		struct ext4_extent_header *ext_block,
1531 		uint32_t fileblock, int log2_blksz)
1532 {
1533 	struct ext4_extent_idx *index;
1534 	unsigned long long block;
1535 	int blksz = EXT2_BLOCK_SIZE(data);
1536 	int i;
1537 
1538 	while (1) {
1539 		index = (struct ext4_extent_idx *)(ext_block + 1);
1540 
1541 		if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
1542 			return NULL;
1543 
1544 		if (ext_block->eh_depth == 0)
1545 			return ext_block;
1546 		i = -1;
1547 		do {
1548 			i++;
1549 			if (i >= le16_to_cpu(ext_block->eh_entries))
1550 				break;
1551 		} while (fileblock >= le32_to_cpu(index[i].ei_block));
1552 
1553 		/*
1554 		 * If first logical block number is higher than requested fileblock,
1555 		 * it is a sparse file. This is handled on upper layer.
1556 		 */
1557 		if (i > 0)
1558 			i--;
1559 
1560 		block = le16_to_cpu(index[i].ei_leaf_hi);
1561 		block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
1562 		block <<= log2_blksz;
1563 		if (!ext_cache_read(cache, (lbaint_t)block, blksz))
1564 			return NULL;
1565 		ext_block = (struct ext4_extent_header *)cache->buf;
1566 	}
1567 }
1568 
ext4fs_blockgroup(struct ext2_data * data,int group,struct ext2_block_group * blkgrp)1569 static int ext4fs_blockgroup
1570 	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
1571 {
1572 	long int blkno;
1573 	unsigned int blkoff, desc_per_blk;
1574 	int log2blksz = get_fs()->dev_desc->log2blksz;
1575 	int desc_size = get_fs()->gdsize;
1576 
1577 	if (desc_size == 0)
1578 		return 0;
1579 	desc_per_blk = EXT2_BLOCK_SIZE(data) / desc_size;
1580 
1581 	if (desc_per_blk == 0)
1582 		return 0;
1583 	blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
1584 			group / desc_per_blk;
1585 	blkoff = (group % desc_per_blk) * desc_size;
1586 
1587 	debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
1588 	      group, blkno, blkoff);
1589 
1590 	return ext4fs_devread((lbaint_t)blkno <<
1591 			      (LOG2_BLOCK_SIZE(data) - log2blksz),
1592 			      blkoff, desc_size, (char *)blkgrp);
1593 }
1594 
ext4fs_read_inode(struct ext2_data * data,int ino,struct ext2_inode * inode)1595 int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
1596 {
1597 	struct ext2_block_group *blkgrp;
1598 	struct ext2_sblock *sblock = &data->sblock;
1599 	struct ext_filesystem *fs = get_fs();
1600 	int log2blksz = get_fs()->dev_desc->log2blksz;
1601 	int inodes_per_block, status;
1602 	long int blkno;
1603 	unsigned int blkoff;
1604 
1605 	/* Allocate blkgrp based on gdsize (for 64-bit support). */
1606 	blkgrp = zalloc(get_fs()->gdsize);
1607 	if (!blkgrp)
1608 		return 0;
1609 
1610 	/* It is easier to calculate if the first inode is 0. */
1611 	ino--;
1612 	if ( le32_to_cpu(sblock->inodes_per_group) == 0 || fs->inodesz == 0) {
1613 		free(blkgrp);
1614 		return 0;
1615 	}
1616 	status = ext4fs_blockgroup(data, ino / le32_to_cpu
1617 				   (sblock->inodes_per_group), blkgrp);
1618 	if (status == 0) {
1619 		free(blkgrp);
1620 		return 0;
1621 	}
1622 
1623 	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
1624 	if ( inodes_per_block == 0 ) {
1625 		free(blkgrp);
1626 		return 0;
1627 	}
1628 	blkno = ext4fs_bg_get_inode_table_id(blkgrp, fs) +
1629 	    (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1630 	blkoff = (ino % inodes_per_block) * fs->inodesz;
1631 
1632 	/* Free blkgrp as it is no longer required. */
1633 	free(blkgrp);
1634 
1635 	/* Read the inode. */
1636 	status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) -
1637 				log2blksz), blkoff,
1638 				sizeof(struct ext2_inode), (char *)inode);
1639 	if (status == 0)
1640 		return 0;
1641 
1642 	return 1;
1643 }
1644 
read_allocated_block(struct ext2_inode * inode,int fileblock,struct ext_block_cache * cache)1645 long int read_allocated_block(struct ext2_inode *inode, int fileblock,
1646 			      struct ext_block_cache *cache)
1647 {
1648 	long int blknr;
1649 	int blksz;
1650 	int log2_blksz;
1651 	int status;
1652 	long int rblock;
1653 	long int perblock_parent;
1654 	long int perblock_child;
1655 	unsigned long long start;
1656 	/* get the blocksize of the filesystem */
1657 	blksz = EXT2_BLOCK_SIZE(ext4fs_root);
1658 	log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
1659 		- get_fs()->dev_desc->log2blksz;
1660 
1661 	if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
1662 		long int startblock, endblock;
1663 		struct ext_block_cache *c, cd;
1664 		struct ext4_extent_header *ext_block;
1665 		struct ext4_extent *extent;
1666 		int i;
1667 
1668 		if (cache) {
1669 			c = cache;
1670 		} else {
1671 			c = &cd;
1672 			ext_cache_init(c);
1673 		}
1674 		ext_block =
1675 			ext4fs_get_extent_block(ext4fs_root, c,
1676 						(struct ext4_extent_header *)
1677 						inode->b.blocks.dir_blocks,
1678 						fileblock, log2_blksz);
1679 		if (!ext_block) {
1680 			printf("invalid extent block\n");
1681 			if (!cache)
1682 				ext_cache_fini(c);
1683 			return -EINVAL;
1684 		}
1685 
1686 		extent = (struct ext4_extent *)(ext_block + 1);
1687 
1688 		for (i = 0; i < le16_to_cpu(ext_block->eh_entries); i++) {
1689 			startblock = le32_to_cpu(extent[i].ee_block);
1690 			endblock = startblock + le16_to_cpu(extent[i].ee_len);
1691 
1692 			if (startblock > fileblock) {
1693 				/* Sparse file */
1694 				if (!cache)
1695 					ext_cache_fini(c);
1696 				return 0;
1697 
1698 			} else if (fileblock < endblock) {
1699 				start = le16_to_cpu(extent[i].ee_start_hi);
1700 				start = (start << 32) +
1701 					le32_to_cpu(extent[i].ee_start_lo);
1702 				if (!cache)
1703 					ext_cache_fini(c);
1704 				return (fileblock - startblock) + start;
1705 			}
1706 		}
1707 
1708 		if (!cache)
1709 			ext_cache_fini(c);
1710 		return 0;
1711 	}
1712 
1713 	/* Direct blocks. */
1714 	if (fileblock < INDIRECT_BLOCKS)
1715 		blknr = le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
1716 
1717 	/* Indirect. */
1718 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
1719 		if (ext4fs_indir1_block == NULL) {
1720 			ext4fs_indir1_block = zalloc(blksz);
1721 			if (ext4fs_indir1_block == NULL) {
1722 				printf("** SI ext2fs read block (indir 1)"
1723 					"malloc failed. **\n");
1724 				return -1;
1725 			}
1726 			ext4fs_indir1_size = blksz;
1727 			ext4fs_indir1_blkno = -1;
1728 		}
1729 		if (blksz != ext4fs_indir1_size) {
1730 			free(ext4fs_indir1_block);
1731 			ext4fs_indir1_block = NULL;
1732 			ext4fs_indir1_size = 0;
1733 			ext4fs_indir1_blkno = -1;
1734 			ext4fs_indir1_block = zalloc(blksz);
1735 			if (ext4fs_indir1_block == NULL) {
1736 				printf("** SI ext2fs read block (indir 1):"
1737 					"malloc failed. **\n");
1738 				return -1;
1739 			}
1740 			ext4fs_indir1_size = blksz;
1741 		}
1742 		if ((le32_to_cpu(inode->b.blocks.indir_block) <<
1743 		     log2_blksz) != ext4fs_indir1_blkno) {
1744 			status =
1745 			    ext4fs_devread((lbaint_t)le32_to_cpu
1746 					   (inode->b.blocks.
1747 					    indir_block) << log2_blksz, 0,
1748 					   blksz, (char *)ext4fs_indir1_block);
1749 			if (status == 0) {
1750 				printf("** SI ext2fs read block (indir 1)"
1751 					"failed. **\n");
1752 				return -1;
1753 			}
1754 			ext4fs_indir1_blkno =
1755 				le32_to_cpu(inode->b.blocks.
1756 					       indir_block) << log2_blksz;
1757 		}
1758 		blknr = le32_to_cpu(ext4fs_indir1_block
1759 				      [fileblock - INDIRECT_BLOCKS]);
1760 	}
1761 	/* Double indirect. */
1762 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
1763 					(blksz / 4 + 1)))) {
1764 
1765 		long int perblock = blksz / 4;
1766 		long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
1767 
1768 		if (ext4fs_indir1_block == NULL) {
1769 			ext4fs_indir1_block = zalloc(blksz);
1770 			if (ext4fs_indir1_block == NULL) {
1771 				printf("** DI ext2fs read block (indir 2 1)"
1772 					"malloc failed. **\n");
1773 				return -1;
1774 			}
1775 			ext4fs_indir1_size = blksz;
1776 			ext4fs_indir1_blkno = -1;
1777 		}
1778 		if (blksz != ext4fs_indir1_size) {
1779 			free(ext4fs_indir1_block);
1780 			ext4fs_indir1_block = NULL;
1781 			ext4fs_indir1_size = 0;
1782 			ext4fs_indir1_blkno = -1;
1783 			ext4fs_indir1_block = zalloc(blksz);
1784 			if (ext4fs_indir1_block == NULL) {
1785 				printf("** DI ext2fs read block (indir 2 1)"
1786 					"malloc failed. **\n");
1787 				return -1;
1788 			}
1789 			ext4fs_indir1_size = blksz;
1790 		}
1791 		if ((le32_to_cpu(inode->b.blocks.double_indir_block) <<
1792 		     log2_blksz) != ext4fs_indir1_blkno) {
1793 			status =
1794 			    ext4fs_devread((lbaint_t)le32_to_cpu
1795 					   (inode->b.blocks.
1796 					    double_indir_block) << log2_blksz,
1797 					   0, blksz,
1798 					   (char *)ext4fs_indir1_block);
1799 			if (status == 0) {
1800 				printf("** DI ext2fs read block (indir 2 1)"
1801 					"failed. **\n");
1802 				return -1;
1803 			}
1804 			ext4fs_indir1_blkno =
1805 			    le32_to_cpu(inode->b.blocks.double_indir_block) <<
1806 			    log2_blksz;
1807 		}
1808 
1809 		if (ext4fs_indir2_block == NULL) {
1810 			ext4fs_indir2_block = zalloc(blksz);
1811 			if (ext4fs_indir2_block == NULL) {
1812 				printf("** DI ext2fs read block (indir 2 2)"
1813 					"malloc failed. **\n");
1814 				return -1;
1815 			}
1816 			ext4fs_indir2_size = blksz;
1817 			ext4fs_indir2_blkno = -1;
1818 		}
1819 		if (blksz != ext4fs_indir2_size) {
1820 			free(ext4fs_indir2_block);
1821 			ext4fs_indir2_block = NULL;
1822 			ext4fs_indir2_size = 0;
1823 			ext4fs_indir2_blkno = -1;
1824 			ext4fs_indir2_block = zalloc(blksz);
1825 			if (ext4fs_indir2_block == NULL) {
1826 				printf("** DI ext2fs read block (indir 2 2)"
1827 					"malloc failed. **\n");
1828 				return -1;
1829 			}
1830 			ext4fs_indir2_size = blksz;
1831 		}
1832 		if ((le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
1833 		     log2_blksz) != ext4fs_indir2_blkno) {
1834 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1835 						(ext4fs_indir1_block
1836 						 [rblock /
1837 						  perblock]) << log2_blksz, 0,
1838 						blksz,
1839 						(char *)ext4fs_indir2_block);
1840 			if (status == 0) {
1841 				printf("** DI ext2fs read block (indir 2 2)"
1842 					"failed. **\n");
1843 				return -1;
1844 			}
1845 			ext4fs_indir2_blkno =
1846 			    le32_to_cpu(ext4fs_indir1_block[rblock
1847 							      /
1848 							      perblock]) <<
1849 			    log2_blksz;
1850 		}
1851 		blknr = le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
1852 	}
1853 	/* Tripple indirect. */
1854 	else {
1855 		rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
1856 				      (blksz / 4 * blksz / 4));
1857 		perblock_child = blksz / 4;
1858 		perblock_parent = ((blksz / 4) * (blksz / 4));
1859 
1860 		if (ext4fs_indir1_block == NULL) {
1861 			ext4fs_indir1_block = zalloc(blksz);
1862 			if (ext4fs_indir1_block == NULL) {
1863 				printf("** TI ext2fs read block (indir 2 1)"
1864 					"malloc failed. **\n");
1865 				return -1;
1866 			}
1867 			ext4fs_indir1_size = blksz;
1868 			ext4fs_indir1_blkno = -1;
1869 		}
1870 		if (blksz != ext4fs_indir1_size) {
1871 			free(ext4fs_indir1_block);
1872 			ext4fs_indir1_block = NULL;
1873 			ext4fs_indir1_size = 0;
1874 			ext4fs_indir1_blkno = -1;
1875 			ext4fs_indir1_block = zalloc(blksz);
1876 			if (ext4fs_indir1_block == NULL) {
1877 				printf("** TI ext2fs read block (indir 2 1)"
1878 					"malloc failed. **\n");
1879 				return -1;
1880 			}
1881 			ext4fs_indir1_size = blksz;
1882 		}
1883 		if ((le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1884 		     log2_blksz) != ext4fs_indir1_blkno) {
1885 			status = ext4fs_devread
1886 			    ((lbaint_t)
1887 			     le32_to_cpu(inode->b.blocks.triple_indir_block)
1888 			     << log2_blksz, 0, blksz,
1889 			     (char *)ext4fs_indir1_block);
1890 			if (status == 0) {
1891 				printf("** TI ext2fs read block (indir 2 1)"
1892 					"failed. **\n");
1893 				return -1;
1894 			}
1895 			ext4fs_indir1_blkno =
1896 			    le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1897 			    log2_blksz;
1898 		}
1899 
1900 		if (ext4fs_indir2_block == NULL) {
1901 			ext4fs_indir2_block = zalloc(blksz);
1902 			if (ext4fs_indir2_block == NULL) {
1903 				printf("** TI ext2fs read block (indir 2 2)"
1904 					"malloc failed. **\n");
1905 				return -1;
1906 			}
1907 			ext4fs_indir2_size = blksz;
1908 			ext4fs_indir2_blkno = -1;
1909 		}
1910 		if (blksz != ext4fs_indir2_size) {
1911 			free(ext4fs_indir2_block);
1912 			ext4fs_indir2_block = NULL;
1913 			ext4fs_indir2_size = 0;
1914 			ext4fs_indir2_blkno = -1;
1915 			ext4fs_indir2_block = zalloc(blksz);
1916 			if (ext4fs_indir2_block == NULL) {
1917 				printf("** TI ext2fs read block (indir 2 2)"
1918 					"malloc failed. **\n");
1919 				return -1;
1920 			}
1921 			ext4fs_indir2_size = blksz;
1922 		}
1923 		if ((le32_to_cpu(ext4fs_indir1_block[rblock /
1924 						       perblock_parent]) <<
1925 		     log2_blksz)
1926 		    != ext4fs_indir2_blkno) {
1927 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1928 						(ext4fs_indir1_block
1929 						 [rblock /
1930 						  perblock_parent]) <<
1931 						log2_blksz, 0, blksz,
1932 						(char *)ext4fs_indir2_block);
1933 			if (status == 0) {
1934 				printf("** TI ext2fs read block (indir 2 2)"
1935 					"failed. **\n");
1936 				return -1;
1937 			}
1938 			ext4fs_indir2_blkno =
1939 			    le32_to_cpu(ext4fs_indir1_block[rblock /
1940 							      perblock_parent])
1941 			    << log2_blksz;
1942 		}
1943 
1944 		if (ext4fs_indir3_block == NULL) {
1945 			ext4fs_indir3_block = zalloc(blksz);
1946 			if (ext4fs_indir3_block == NULL) {
1947 				printf("** TI ext2fs read block (indir 2 2)"
1948 					"malloc failed. **\n");
1949 				return -1;
1950 			}
1951 			ext4fs_indir3_size = blksz;
1952 			ext4fs_indir3_blkno = -1;
1953 		}
1954 		if (blksz != ext4fs_indir3_size) {
1955 			free(ext4fs_indir3_block);
1956 			ext4fs_indir3_block = NULL;
1957 			ext4fs_indir3_size = 0;
1958 			ext4fs_indir3_blkno = -1;
1959 			ext4fs_indir3_block = zalloc(blksz);
1960 			if (ext4fs_indir3_block == NULL) {
1961 				printf("** TI ext2fs read block (indir 2 2)"
1962 					"malloc failed. **\n");
1963 				return -1;
1964 			}
1965 			ext4fs_indir3_size = blksz;
1966 		}
1967 		if ((le32_to_cpu(ext4fs_indir2_block[rblock
1968 						       /
1969 						       perblock_child]) <<
1970 		     log2_blksz) != ext4fs_indir3_blkno) {
1971 			status =
1972 			    ext4fs_devread((lbaint_t)le32_to_cpu
1973 					   (ext4fs_indir2_block
1974 					    [(rblock / perblock_child)
1975 					     % (blksz / 4)]) << log2_blksz, 0,
1976 					   blksz, (char *)ext4fs_indir3_block);
1977 			if (status == 0) {
1978 				printf("** TI ext2fs read block (indir 2 2)"
1979 				       "failed. **\n");
1980 				return -1;
1981 			}
1982 			ext4fs_indir3_blkno =
1983 			    le32_to_cpu(ext4fs_indir2_block[(rblock /
1984 							       perblock_child) %
1985 							      (blksz /
1986 							       4)]) <<
1987 			    log2_blksz;
1988 		}
1989 
1990 		blknr = le32_to_cpu(ext4fs_indir3_block
1991 				      [rblock % perblock_child]);
1992 	}
1993 	debug("read_allocated_block %ld\n", blknr);
1994 
1995 	return blknr;
1996 }
1997 
1998 /**
1999  * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's
2000  *			    global pointers
2001  *
2002  * This function assures that for a file with the same name but different size
2003  * the sequential store on the ext4 filesystem will be correct.
2004  *
2005  * In this function the global data, responsible for internal representation
2006  * of the ext4 data are initialized to the reset state. Without this, during
2007  * replacement of the smaller file with the bigger truncation of new file was
2008  * performed.
2009  */
ext4fs_reinit_global(void)2010 void ext4fs_reinit_global(void)
2011 {
2012 	if (ext4fs_indir1_block != NULL) {
2013 		free(ext4fs_indir1_block);
2014 		ext4fs_indir1_block = NULL;
2015 		ext4fs_indir1_size = 0;
2016 		ext4fs_indir1_blkno = -1;
2017 	}
2018 	if (ext4fs_indir2_block != NULL) {
2019 		free(ext4fs_indir2_block);
2020 		ext4fs_indir2_block = NULL;
2021 		ext4fs_indir2_size = 0;
2022 		ext4fs_indir2_blkno = -1;
2023 	}
2024 	if (ext4fs_indir3_block != NULL) {
2025 		free(ext4fs_indir3_block);
2026 		ext4fs_indir3_block = NULL;
2027 		ext4fs_indir3_size = 0;
2028 		ext4fs_indir3_blkno = -1;
2029 	}
2030 }
ext4fs_close(void)2031 void ext4fs_close(void)
2032 {
2033 	if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
2034 		ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
2035 		ext4fs_file = NULL;
2036 	}
2037 	if (ext4fs_root != NULL) {
2038 		free(ext4fs_root);
2039 		ext4fs_root = NULL;
2040 	}
2041 
2042 	ext4fs_reinit_global();
2043 }
2044 
ext4fs_iterate_dir(struct ext2fs_node * dir,char * name,struct ext2fs_node ** fnode,int * ftype)2045 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
2046 				struct ext2fs_node **fnode, int *ftype)
2047 {
2048 	unsigned int fpos = 0;
2049 	int status;
2050 	loff_t actread;
2051 	struct ext2fs_node *diro = (struct ext2fs_node *) dir;
2052 
2053 #ifdef DEBUG
2054 	if (name != NULL)
2055 		printf("Iterate dir %s\n", name);
2056 #endif /* of DEBUG */
2057 	if (!diro->inode_read) {
2058 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2059 		if (status == 0)
2060 			return 0;
2061 	}
2062 	/* Search the file.  */
2063 	while (fpos < le32_to_cpu(diro->inode.size)) {
2064 		struct ext2_dirent dirent;
2065 
2066 		status = ext4fs_read_file(diro, fpos,
2067 					   sizeof(struct ext2_dirent),
2068 					   (char *)&dirent, &actread);
2069 		if (status < 0)
2070 			return 0;
2071 
2072 		if (dirent.direntlen == 0) {
2073 			printf("Failed to iterate over directory %s\n", name);
2074 			return 0;
2075 		}
2076 
2077 		if (dirent.namelen != 0) {
2078 			char filename[dirent.namelen + 1];
2079 			struct ext2fs_node *fdiro;
2080 			int type = FILETYPE_UNKNOWN;
2081 
2082 			status = ext4fs_read_file(diro,
2083 						  fpos +
2084 						  sizeof(struct ext2_dirent),
2085 						  dirent.namelen, filename,
2086 						  &actread);
2087 			if (status < 0)
2088 				return 0;
2089 
2090 			fdiro = zalloc(sizeof(struct ext2fs_node));
2091 			if (!fdiro)
2092 				return 0;
2093 
2094 			fdiro->data = diro->data;
2095 			fdiro->ino = le32_to_cpu(dirent.inode);
2096 
2097 			filename[dirent.namelen] = '\0';
2098 
2099 			if (dirent.filetype != FILETYPE_UNKNOWN) {
2100 				fdiro->inode_read = 0;
2101 
2102 				if (dirent.filetype == FILETYPE_DIRECTORY)
2103 					type = FILETYPE_DIRECTORY;
2104 				else if (dirent.filetype == FILETYPE_SYMLINK)
2105 					type = FILETYPE_SYMLINK;
2106 				else if (dirent.filetype == FILETYPE_REG)
2107 					type = FILETYPE_REG;
2108 			} else {
2109 				status = ext4fs_read_inode(diro->data,
2110 							   le32_to_cpu
2111 							   (dirent.inode),
2112 							   &fdiro->inode);
2113 				if (status == 0) {
2114 					free(fdiro);
2115 					return 0;
2116 				}
2117 				fdiro->inode_read = 1;
2118 
2119 				if ((le16_to_cpu(fdiro->inode.mode) &
2120 				     FILETYPE_INO_MASK) ==
2121 				    FILETYPE_INO_DIRECTORY) {
2122 					type = FILETYPE_DIRECTORY;
2123 				} else if ((le16_to_cpu(fdiro->inode.mode)
2124 					    & FILETYPE_INO_MASK) ==
2125 					   FILETYPE_INO_SYMLINK) {
2126 					type = FILETYPE_SYMLINK;
2127 				} else if ((le16_to_cpu(fdiro->inode.mode)
2128 					    & FILETYPE_INO_MASK) ==
2129 					   FILETYPE_INO_REG) {
2130 					type = FILETYPE_REG;
2131 				}
2132 			}
2133 #ifdef DEBUG
2134 			printf("iterate >%s<\n", filename);
2135 #endif /* of DEBUG */
2136 			if ((name != NULL) && (fnode != NULL)
2137 			    && (ftype != NULL)) {
2138 				if (strcmp(filename, name) == 0) {
2139 					*ftype = type;
2140 					*fnode = fdiro;
2141 					return 1;
2142 				}
2143 			} else {
2144 				if (fdiro->inode_read == 0) {
2145 					status = ext4fs_read_inode(diro->data,
2146 								 le32_to_cpu(
2147 								 dirent.inode),
2148 								 &fdiro->inode);
2149 					if (status == 0) {
2150 						free(fdiro);
2151 						return 0;
2152 					}
2153 					fdiro->inode_read = 1;
2154 				}
2155 				switch (type) {
2156 				case FILETYPE_DIRECTORY:
2157 					printf("<DIR> ");
2158 					break;
2159 				case FILETYPE_SYMLINK:
2160 					printf("<SYM> ");
2161 					break;
2162 				case FILETYPE_REG:
2163 					printf("      ");
2164 					break;
2165 				default:
2166 					printf("< ? > ");
2167 					break;
2168 				}
2169 				printf("%10u %s\n",
2170 				       le32_to_cpu(fdiro->inode.size),
2171 					filename);
2172 			}
2173 			free(fdiro);
2174 		}
2175 		fpos += le16_to_cpu(dirent.direntlen);
2176 	}
2177 	return 0;
2178 }
2179 
ext4fs_read_symlink(struct ext2fs_node * node)2180 static char *ext4fs_read_symlink(struct ext2fs_node *node)
2181 {
2182 	char *symlink;
2183 	struct ext2fs_node *diro = node;
2184 	int status;
2185 	loff_t actread;
2186 
2187 	if (!diro->inode_read) {
2188 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2189 		if (status == 0)
2190 			return NULL;
2191 	}
2192 	symlink = zalloc(le32_to_cpu(diro->inode.size) + 1);
2193 	if (!symlink)
2194 		return NULL;
2195 
2196 	if (le32_to_cpu(diro->inode.size) < sizeof(diro->inode.b.symlink)) {
2197 		strncpy(symlink, diro->inode.b.symlink,
2198 			 le32_to_cpu(diro->inode.size));
2199 	} else {
2200 		status = ext4fs_read_file(diro, 0,
2201 					   le32_to_cpu(diro->inode.size),
2202 					   symlink, &actread);
2203 		if ((status < 0) || (actread == 0)) {
2204 			free(symlink);
2205 			return NULL;
2206 		}
2207 	}
2208 	symlink[le32_to_cpu(diro->inode.size)] = '\0';
2209 	return symlink;
2210 }
2211 
ext4fs_find_file1(const char * currpath,struct ext2fs_node * currroot,struct ext2fs_node ** currfound,int * foundtype)2212 static int ext4fs_find_file1(const char *currpath,
2213 			     struct ext2fs_node *currroot,
2214 			     struct ext2fs_node **currfound, int *foundtype)
2215 {
2216 	char fpath[strlen(currpath) + 1];
2217 	char *name = fpath;
2218 	char *next;
2219 	int status;
2220 	int type = FILETYPE_DIRECTORY;
2221 	struct ext2fs_node *currnode = currroot;
2222 	struct ext2fs_node *oldnode = currroot;
2223 
2224 	strncpy(fpath, currpath, strlen(currpath) + 1);
2225 
2226 	/* Remove all leading slashes. */
2227 	while (*name == '/')
2228 		name++;
2229 
2230 	if (!*name) {
2231 		*currfound = currnode;
2232 		return 1;
2233 	}
2234 
2235 	for (;;) {
2236 		int found;
2237 
2238 		/* Extract the actual part from the pathname. */
2239 		next = strchr(name, '/');
2240 		if (next) {
2241 			/* Remove all leading slashes. */
2242 			while (*next == '/')
2243 				*(next++) = '\0';
2244 		}
2245 
2246 		if (type != FILETYPE_DIRECTORY) {
2247 			ext4fs_free_node(currnode, currroot);
2248 			return 0;
2249 		}
2250 
2251 		oldnode = currnode;
2252 
2253 		/* Iterate over the directory. */
2254 		found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
2255 		if (found == 0)
2256 			return 0;
2257 
2258 		if (found == -1)
2259 			break;
2260 
2261 		/* Read in the symlink and follow it. */
2262 		if (type == FILETYPE_SYMLINK) {
2263 			char *symlink;
2264 
2265 			/* Test if the symlink does not loop. */
2266 			if (++symlinknest == 8) {
2267 				ext4fs_free_node(currnode, currroot);
2268 				ext4fs_free_node(oldnode, currroot);
2269 				return 0;
2270 			}
2271 
2272 			symlink = ext4fs_read_symlink(currnode);
2273 			ext4fs_free_node(currnode, currroot);
2274 
2275 			if (!symlink) {
2276 				ext4fs_free_node(oldnode, currroot);
2277 				return 0;
2278 			}
2279 
2280 			debug("Got symlink >%s<\n", symlink);
2281 
2282 			if (symlink[0] == '/') {
2283 				ext4fs_free_node(oldnode, currroot);
2284 				oldnode = &ext4fs_root->diropen;
2285 			}
2286 
2287 			/* Lookup the node the symlink points to. */
2288 			status = ext4fs_find_file1(symlink, oldnode,
2289 						    &currnode, &type);
2290 
2291 			free(symlink);
2292 
2293 			if (status == 0) {
2294 				ext4fs_free_node(oldnode, currroot);
2295 				return 0;
2296 			}
2297 		}
2298 
2299 		ext4fs_free_node(oldnode, currroot);
2300 
2301 		/* Found the node! */
2302 		if (!next || *next == '\0') {
2303 			*currfound = currnode;
2304 			*foundtype = type;
2305 			return 1;
2306 		}
2307 		name = next;
2308 	}
2309 	return -1;
2310 }
2311 
ext4fs_find_file(const char * path,struct ext2fs_node * rootnode,struct ext2fs_node ** foundnode,int expecttype)2312 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
2313 	struct ext2fs_node **foundnode, int expecttype)
2314 {
2315 	int status;
2316 	int foundtype = FILETYPE_DIRECTORY;
2317 
2318 	symlinknest = 0;
2319 	if (!path)
2320 		return 0;
2321 
2322 	status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
2323 	if (status == 0)
2324 		return 0;
2325 
2326 	/* Check if the node that was found was of the expected type. */
2327 	if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
2328 		return 0;
2329 	else if ((expecttype == FILETYPE_DIRECTORY)
2330 		   && (foundtype != expecttype))
2331 		return 0;
2332 
2333 	return 1;
2334 }
2335 
ext4fs_open(const char * filename,loff_t * len)2336 int ext4fs_open(const char *filename, loff_t *len)
2337 {
2338 	struct ext2fs_node *fdiro = NULL;
2339 	int status;
2340 
2341 	if (ext4fs_root == NULL)
2342 		return -1;
2343 
2344 	ext4fs_file = NULL;
2345 	status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
2346 				  FILETYPE_REG);
2347 	if (status == 0)
2348 		goto fail;
2349 
2350 	if (!fdiro->inode_read) {
2351 		status = ext4fs_read_inode(fdiro->data, fdiro->ino,
2352 				&fdiro->inode);
2353 		if (status == 0)
2354 			goto fail;
2355 	}
2356 	*len = le32_to_cpu(fdiro->inode.size);
2357 	ext4fs_file = fdiro;
2358 
2359 	return 0;
2360 fail:
2361 	ext4fs_free_node(fdiro, &ext4fs_root->diropen);
2362 
2363 	return -1;
2364 }
2365 
ext4fs_mount(unsigned part_length)2366 int ext4fs_mount(unsigned part_length)
2367 {
2368 	struct ext2_data *data;
2369 	int status;
2370 	struct ext_filesystem *fs = get_fs();
2371 	data = zalloc(SUPERBLOCK_SIZE);
2372 	if (!data)
2373 		return 0;
2374 
2375 	/* Read the superblock. */
2376 	status = ext4_read_superblock((char *)&data->sblock);
2377 
2378 	if (status == 0)
2379 		goto fail;
2380 
2381 	/* Make sure this is an ext2 filesystem. */
2382 	if (le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
2383 		goto fail_noerr;
2384 
2385 
2386 	if (le32_to_cpu(data->sblock.revision_level) == 0) {
2387 		fs->inodesz = 128;
2388 		fs->gdsize = 32;
2389 	} else {
2390 		debug("EXT4 features COMPAT: %08x INCOMPAT: %08x RO_COMPAT: %08x\n",
2391 		      __le32_to_cpu(data->sblock.feature_compatibility),
2392 		      __le32_to_cpu(data->sblock.feature_incompat),
2393 		      __le32_to_cpu(data->sblock.feature_ro_compat));
2394 
2395 		fs->inodesz = le16_to_cpu(data->sblock.inode_size);
2396 		fs->gdsize = le32_to_cpu(data->sblock.feature_incompat) &
2397 			EXT4_FEATURE_INCOMPAT_64BIT ?
2398 			le16_to_cpu(data->sblock.descriptor_size) : 32;
2399 	}
2400 
2401 	debug("EXT2 rev %d, inode_size %d, descriptor size %d\n",
2402 	      le32_to_cpu(data->sblock.revision_level),
2403 	      fs->inodesz, fs->gdsize);
2404 
2405 	data->diropen.data = data;
2406 	data->diropen.ino = 2;
2407 	data->diropen.inode_read = 1;
2408 	data->inode = &data->diropen.inode;
2409 
2410 	status = ext4fs_read_inode(data, 2, data->inode);
2411 	if (status == 0)
2412 		goto fail;
2413 
2414 	ext4fs_root = data;
2415 
2416 	return 1;
2417 fail:
2418 	printf("Failed to mount ext2 filesystem...\n");
2419 fail_noerr:
2420 	free(data);
2421 	ext4fs_root = NULL;
2422 
2423 	return 0;
2424 }
2425