xref: /openbmc/u-boot/fs/ext4/ext4_common.c (revision 9f5dd8b6e2ff0f1553cc71aaf6cb53adb9c7f5e6)
1 /*
2  * (C) Copyright 2011 - 2012 Samsung Electronics
3  * EXT4 filesystem implementation in Uboot by
4  * Uma Shankar <uma.shankar@samsung.com>
5  * Manjunatha C Achar <a.manjunatha@samsung.com>
6  *
7  * ext4ls and ext4load : Based on ext2 ls load support in Uboot.
8  *
9  * (C) Copyright 2004
10  * esd gmbh <www.esd-electronics.com>
11  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
12  *
13  * based on code from grub2 fs/ext2.c and fs/fshelp.c by
14  * GRUB  --  GRand Unified Bootloader
15  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
16  *
17  * ext4write : Based on generic ext4 protocol.
18  *
19  * SPDX-License-Identifier:	GPL-2.0+
20  */
21 
22 #include <common.h>
23 #include <ext_common.h>
24 #include <ext4fs.h>
25 #include <inttypes.h>
26 #include <malloc.h>
27 #include <memalign.h>
28 #include <stddef.h>
29 #include <linux/stat.h>
30 #include <linux/time.h>
31 #include <asm/byteorder.h>
32 #include "ext4_common.h"
33 
34 struct ext2_data *ext4fs_root;
35 struct ext2fs_node *ext4fs_file;
36 __le32 *ext4fs_indir1_block;
37 int ext4fs_indir1_size;
38 int ext4fs_indir1_blkno = -1;
39 __le32 *ext4fs_indir2_block;
40 int ext4fs_indir2_size;
41 int ext4fs_indir2_blkno = -1;
42 
43 __le32 *ext4fs_indir3_block;
44 int ext4fs_indir3_size;
45 int ext4fs_indir3_blkno = -1;
46 struct ext2_inode *g_parent_inode;
47 static int symlinknest;
48 
49 #if defined(CONFIG_EXT4_WRITE)
50 struct ext2_block_group *ext4fs_get_group_descriptor
51 	(const struct ext_filesystem *fs, uint32_t bg_idx)
52 {
53 	return (struct ext2_block_group *)(fs->gdtable + (bg_idx * fs->gdsize));
54 }
55 
56 static inline void ext4fs_sb_free_inodes_dec(struct ext2_sblock *sb)
57 {
58 	sb->free_inodes = cpu_to_le32(le32_to_cpu(sb->free_inodes) - 1);
59 }
60 
61 static inline void ext4fs_sb_free_blocks_dec(struct ext2_sblock *sb)
62 {
63 	sb->free_blocks = cpu_to_le32(le32_to_cpu(sb->free_blocks) - 1);
64 }
65 
66 static inline void ext4fs_bg_free_inodes_dec(struct ext2_block_group *bg)
67 {
68 	bg->free_inodes = cpu_to_le16(le16_to_cpu(bg->free_inodes) - 1);
69 }
70 
71 static inline void ext4fs_bg_free_blocks_dec(struct ext2_block_group *bg)
72 {
73 	bg->free_blocks = cpu_to_le16(le16_to_cpu(bg->free_blocks) - 1);
74 }
75 
76 static inline void ext4fs_bg_itable_unused_dec(struct ext2_block_group *bg)
77 {
78 	bg->bg_itable_unused = cpu_to_le16(le16_to_cpu(bg->bg_itable_unused) - 1);
79 }
80 
81 uint64_t ext4fs_sb_get_free_blocks(const struct ext2_sblock *sb)
82 {
83 	uint64_t free_blocks = le32_to_cpu(sb->free_blocks);
84 	free_blocks += (uint64_t)le32_to_cpu(sb->free_blocks_high) << 32;
85 	return free_blocks;
86 }
87 
88 void ext4fs_sb_set_free_blocks(struct ext2_sblock *sb, uint64_t free_blocks)
89 {
90 	sb->free_blocks = cpu_to_le32(free_blocks & 0xffffffff);
91 	sb->free_blocks_high = cpu_to_le16(free_blocks >> 32);
92 }
93 
94 uint32_t ext4fs_bg_get_free_blocks(const struct ext2_block_group *bg,
95 				   const struct ext_filesystem *fs)
96 {
97 	uint32_t free_blocks = le16_to_cpu(bg->free_blocks);
98 	if (fs->gdsize == 64)
99 		free_blocks += le16_to_cpu(bg->free_blocks_high) << 16;
100 	return free_blocks;
101 }
102 
103 static inline
104 uint32_t ext4fs_bg_get_free_inodes(const struct ext2_block_group *bg,
105 				   const struct ext_filesystem *fs)
106 {
107 	uint32_t free_inodes = le16_to_cpu(bg->free_inodes);
108 	if (fs->gdsize == 64)
109 		free_inodes += le16_to_cpu(bg->free_inodes_high) << 16;
110 	return free_inodes;
111 }
112 
113 static inline uint16_t ext4fs_bg_get_flags(const struct ext2_block_group *bg)
114 {
115 	return le16_to_cpu(bg->bg_flags);
116 }
117 
118 static inline void ext4fs_bg_set_flags(struct ext2_block_group *bg,
119 				       uint16_t flags)
120 {
121 	bg->bg_flags = cpu_to_le16(flags);
122 }
123 
124 /* Block number of the block bitmap */
125 uint64_t ext4fs_bg_get_block_id(const struct ext2_block_group *bg,
126 				const struct ext_filesystem *fs)
127 {
128 	uint64_t block_nr = le32_to_cpu(bg->block_id);
129 	if (fs->gdsize == 64)
130 		block_nr += (uint64_t)le32_to_cpu(bg->block_id_high) << 32;
131 	return block_nr;
132 }
133 
134 /* Block number of the inode bitmap */
135 uint64_t ext4fs_bg_get_inode_id(const struct ext2_block_group *bg,
136 				const struct ext_filesystem *fs)
137 {
138 	uint64_t block_nr = le32_to_cpu(bg->inode_id);
139 	if (fs->gdsize == 64)
140 		block_nr += (uint64_t)le32_to_cpu(bg->inode_id_high) << 32;
141 	return block_nr;
142 }
143 #endif
144 
145 /* Block number of the inode table */
146 uint64_t ext4fs_bg_get_inode_table_id(const struct ext2_block_group *bg,
147 				      const struct ext_filesystem *fs)
148 {
149 	uint64_t block_nr = le32_to_cpu(bg->inode_table_id);
150 	if (fs->gdsize == 64)
151 		block_nr +=
152 			(uint64_t)le32_to_cpu(bg->inode_table_id_high) << 32;
153 	return block_nr;
154 }
155 
156 #if defined(CONFIG_EXT4_WRITE)
157 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n)
158 {
159 	uint32_t res = size / n;
160 	if (res * n != size)
161 		res++;
162 
163 	return res;
164 }
165 
166 void put_ext4(uint64_t off, void *buf, uint32_t size)
167 {
168 	uint64_t startblock;
169 	uint64_t remainder;
170 	unsigned char *temp_ptr = NULL;
171 	struct ext_filesystem *fs = get_fs();
172 	int log2blksz = fs->dev_desc->log2blksz;
173 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, sec_buf, fs->dev_desc->blksz);
174 
175 	startblock = off >> log2blksz;
176 	startblock += part_offset;
177 	remainder = off & (uint64_t)(fs->dev_desc->blksz - 1);
178 
179 	if (fs->dev_desc == NULL)
180 		return;
181 
182 	if ((startblock + (size >> log2blksz)) >
183 	    (part_offset + fs->total_sect)) {
184 		printf("part_offset is " LBAFU "\n", part_offset);
185 		printf("total_sector is %" PRIu64 "\n", fs->total_sect);
186 		printf("error: overflow occurs\n");
187 		return;
188 	}
189 
190 	if (remainder) {
191 		blk_dread(fs->dev_desc, startblock, 1, sec_buf);
192 		temp_ptr = sec_buf;
193 		memcpy((temp_ptr + remainder), (unsigned char *)buf, size);
194 		blk_dwrite(fs->dev_desc, startblock, 1, sec_buf);
195 	} else {
196 		if (size >> log2blksz != 0) {
197 			blk_dwrite(fs->dev_desc, startblock, size >> log2blksz,
198 				   (unsigned long *)buf);
199 		} else {
200 			blk_dread(fs->dev_desc, startblock, 1, sec_buf);
201 			temp_ptr = sec_buf;
202 			memcpy(temp_ptr, buf, size);
203 			blk_dwrite(fs->dev_desc, startblock, 1,
204 				   (unsigned long *)sec_buf);
205 		}
206 	}
207 }
208 
209 static int _get_new_inode_no(unsigned char *buffer)
210 {
211 	struct ext_filesystem *fs = get_fs();
212 	unsigned char input;
213 	int operand, status;
214 	int count = 1;
215 	int j = 0;
216 
217 	/* get the blocksize of the filesystem */
218 	unsigned char *ptr = buffer;
219 	while (*ptr == 255) {
220 		ptr++;
221 		count += 8;
222 		if (count > le32_to_cpu(ext4fs_root->sblock.inodes_per_group))
223 			return -1;
224 	}
225 
226 	for (j = 0; j < fs->blksz; j++) {
227 		input = *ptr;
228 		int i = 0;
229 		while (i <= 7) {
230 			operand = 1 << i;
231 			status = input & operand;
232 			if (status) {
233 				i++;
234 				count++;
235 			} else {
236 				*ptr |= operand;
237 				return count;
238 			}
239 		}
240 		ptr = ptr + 1;
241 	}
242 
243 	return -1;
244 }
245 
246 static int _get_new_blk_no(unsigned char *buffer)
247 {
248 	int operand;
249 	int count = 0;
250 	int i;
251 	unsigned char *ptr = buffer;
252 	struct ext_filesystem *fs = get_fs();
253 
254 	while (*ptr == 255) {
255 		ptr++;
256 		count += 8;
257 		if (count == (fs->blksz * 8))
258 			return -1;
259 	}
260 
261 	if (fs->blksz == 1024)
262 		count += 1;
263 
264 	for (i = 0; i <= 7; i++) {
265 		operand = 1 << i;
266 		if (*ptr & operand) {
267 			count++;
268 		} else {
269 			*ptr |= operand;
270 			return count;
271 		}
272 	}
273 
274 	return -1;
275 }
276 
277 int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index)
278 {
279 	int i, remainder, status;
280 	unsigned char *ptr = buffer;
281 	unsigned char operand;
282 	i = blockno / 8;
283 	remainder = blockno % 8;
284 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
285 
286 	i = i - (index * blocksize);
287 	if (blocksize != 1024) {
288 		ptr = ptr + i;
289 		operand = 1 << remainder;
290 		status = *ptr & operand;
291 		if (status)
292 			return -1;
293 
294 		*ptr = *ptr | operand;
295 		return 0;
296 	} else {
297 		if (remainder == 0) {
298 			ptr = ptr + i - 1;
299 			operand = (1 << 7);
300 		} else {
301 			ptr = ptr + i;
302 			operand = (1 << (remainder - 1));
303 		}
304 		status = *ptr & operand;
305 		if (status)
306 			return -1;
307 
308 		*ptr = *ptr | operand;
309 		return 0;
310 	}
311 }
312 
313 void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index)
314 {
315 	int i, remainder, status;
316 	unsigned char *ptr = buffer;
317 	unsigned char operand;
318 	i = blockno / 8;
319 	remainder = blockno % 8;
320 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
321 
322 	i = i - (index * blocksize);
323 	if (blocksize != 1024) {
324 		ptr = ptr + i;
325 		operand = (1 << remainder);
326 		status = *ptr & operand;
327 		if (status)
328 			*ptr = *ptr & ~(operand);
329 	} else {
330 		if (remainder == 0) {
331 			ptr = ptr + i - 1;
332 			operand = (1 << 7);
333 		} else {
334 			ptr = ptr + i;
335 			operand = (1 << (remainder - 1));
336 		}
337 		status = *ptr & operand;
338 		if (status)
339 			*ptr = *ptr & ~(operand);
340 	}
341 }
342 
343 int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index)
344 {
345 	int i, remainder, status;
346 	unsigned char *ptr = buffer;
347 	unsigned char operand;
348 
349 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
350 	i = inode_no / 8;
351 	remainder = inode_no % 8;
352 	if (remainder == 0) {
353 		ptr = ptr + i - 1;
354 		operand = (1 << 7);
355 	} else {
356 		ptr = ptr + i;
357 		operand = (1 << (remainder - 1));
358 	}
359 	status = *ptr & operand;
360 	if (status)
361 		return -1;
362 
363 	*ptr = *ptr | operand;
364 
365 	return 0;
366 }
367 
368 void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index)
369 {
370 	int i, remainder, status;
371 	unsigned char *ptr = buffer;
372 	unsigned char operand;
373 
374 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
375 	i = inode_no / 8;
376 	remainder = inode_no % 8;
377 	if (remainder == 0) {
378 		ptr = ptr + i - 1;
379 		operand = (1 << 7);
380 	} else {
381 		ptr = ptr + i;
382 		operand = (1 << (remainder - 1));
383 	}
384 	status = *ptr & operand;
385 	if (status)
386 		*ptr = *ptr & ~(operand);
387 }
388 
389 uint16_t ext4fs_checksum_update(uint32_t i)
390 {
391 	struct ext2_block_group *desc;
392 	struct ext_filesystem *fs = get_fs();
393 	uint16_t crc = 0;
394 	__le32 le32_i = cpu_to_le32(i);
395 
396 	desc = (struct ext2_block_group *)&fs->bgd[i];
397 	if (le32_to_cpu(fs->sb->feature_ro_compat) & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
398 		int offset = offsetof(struct ext2_block_group, bg_checksum);
399 
400 		crc = ext2fs_crc16(~0, fs->sb->unique_id,
401 				   sizeof(fs->sb->unique_id));
402 		crc = ext2fs_crc16(crc, &le32_i, sizeof(le32_i));
403 		crc = ext2fs_crc16(crc, desc, offset);
404 		offset += sizeof(desc->bg_checksum);	/* skip checksum */
405 		assert(offset == sizeof(*desc));
406 	}
407 
408 	return crc;
409 }
410 
411 static int check_void_in_dentry(struct ext2_dirent *dir, char *filename)
412 {
413 	int dentry_length;
414 	int sizeof_void_space;
415 	int new_entry_byte_reqd;
416 	short padding_factor = 0;
417 
418 	if (dir->namelen % 4 != 0)
419 		padding_factor = 4 - (dir->namelen % 4);
420 
421 	dentry_length = sizeof(struct ext2_dirent) +
422 			dir->namelen + padding_factor;
423 	sizeof_void_space = le16_to_cpu(dir->direntlen) - dentry_length;
424 	if (sizeof_void_space == 0)
425 		return 0;
426 
427 	padding_factor = 0;
428 	if (strlen(filename) % 4 != 0)
429 		padding_factor = 4 - (strlen(filename) % 4);
430 
431 	new_entry_byte_reqd = strlen(filename) +
432 	    sizeof(struct ext2_dirent) + padding_factor;
433 	if (sizeof_void_space >= new_entry_byte_reqd) {
434 		dir->direntlen = cpu_to_le16(dentry_length);
435 		return sizeof_void_space;
436 	}
437 
438 	return 0;
439 }
440 
441 int ext4fs_update_parent_dentry(char *filename, int file_type)
442 {
443 	unsigned int *zero_buffer = NULL;
444 	char *root_first_block_buffer = NULL;
445 	int blk_idx;
446 	long int first_block_no_of_root = 0;
447 	int totalbytes = 0;
448 	unsigned int new_entry_byte_reqd;
449 	int sizeof_void_space = 0;
450 	int templength = 0;
451 	int inodeno = -1;
452 	int status;
453 	struct ext_filesystem *fs = get_fs();
454 	/* directory entry */
455 	struct ext2_dirent *dir;
456 	char *temp_dir = NULL;
457 	uint32_t new_blk_no;
458 	uint32_t new_size;
459 	uint32_t new_blockcnt;
460 	uint32_t directory_blocks;
461 
462 	zero_buffer = zalloc(fs->blksz);
463 	if (!zero_buffer) {
464 		printf("No Memory\n");
465 		return -1;
466 	}
467 	root_first_block_buffer = zalloc(fs->blksz);
468 	if (!root_first_block_buffer) {
469 		free(zero_buffer);
470 		printf("No Memory\n");
471 		return -1;
472 	}
473 	new_entry_byte_reqd = ROUND(strlen(filename) +
474 				    sizeof(struct ext2_dirent), 4);
475 restart:
476 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
477 		LOG2_BLOCK_SIZE(ext4fs_root);
478 	blk_idx = directory_blocks - 1;
479 
480 restart_read:
481 	/* read the block no allocated to a file */
482 	first_block_no_of_root = read_allocated_block(g_parent_inode, blk_idx);
483 	if (first_block_no_of_root <= 0)
484 		goto fail;
485 
486 	status = ext4fs_devread((lbaint_t)first_block_no_of_root
487 				* fs->sect_perblk,
488 				0, fs->blksz, root_first_block_buffer);
489 	if (status == 0)
490 		goto fail;
491 
492 	if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
493 		goto fail;
494 	dir = (struct ext2_dirent *)root_first_block_buffer;
495 	totalbytes = 0;
496 
497 	while (le16_to_cpu(dir->direntlen) > 0) {
498 		unsigned short used_len = ROUND(dir->namelen +
499 		    sizeof(struct ext2_dirent), 4);
500 
501 		/* last entry of block */
502 		if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen)) {
503 
504 			/* check if new entry fits */
505 			if ((used_len + new_entry_byte_reqd) <=
506 			    le16_to_cpu(dir->direntlen)) {
507 				dir->direntlen = cpu_to_le16(used_len);
508 				break;
509 			} else {
510 				if (blk_idx > 0) {
511 					printf("Block full, trying previous\n");
512 					blk_idx--;
513 					goto restart_read;
514 				}
515 				printf("All blocks full: Allocate new\n");
516 
517 				if (le32_to_cpu(g_parent_inode->flags) &
518 						EXT4_EXTENTS_FL) {
519 					printf("Directory uses extents\n");
520 					goto fail;
521 				}
522 				if (directory_blocks >= INDIRECT_BLOCKS) {
523 					printf("Directory exceeds limit\n");
524 					goto fail;
525 				}
526 				new_blk_no = ext4fs_get_new_blk_no();
527 				if (new_blk_no == -1) {
528 					printf("no block left to assign\n");
529 					goto fail;
530 				}
531 				put_ext4((uint64_t)new_blk_no * fs->blksz, zero_buffer, fs->blksz);
532 				g_parent_inode->b.blocks.
533 					dir_blocks[directory_blocks] =
534 					cpu_to_le32(new_blk_no);
535 
536 				new_size = le32_to_cpu(g_parent_inode->size);
537 				new_size += fs->blksz;
538 				g_parent_inode->size = cpu_to_le32(new_size);
539 
540 				new_blockcnt = le32_to_cpu(g_parent_inode->blockcnt);
541 				new_blockcnt += fs->sect_perblk;
542 				g_parent_inode->blockcnt = cpu_to_le32(new_blockcnt);
543 
544 				if (ext4fs_put_metadata
545 				    (root_first_block_buffer,
546 				     first_block_no_of_root))
547 					goto fail;
548 				goto restart;
549 			}
550 		}
551 
552 		templength = le16_to_cpu(dir->direntlen);
553 		totalbytes = totalbytes + templength;
554 		sizeof_void_space = check_void_in_dentry(dir, filename);
555 		if (sizeof_void_space)
556 			break;
557 
558 		dir = (struct ext2_dirent *)((char *)dir + templength);
559 	}
560 
561 	/* make a pointer ready for creating next directory entry */
562 	templength = le16_to_cpu(dir->direntlen);
563 	totalbytes = totalbytes + templength;
564 	dir = (struct ext2_dirent *)((char *)dir + templength);
565 
566 	/* get the next available inode number */
567 	inodeno = ext4fs_get_new_inode_no();
568 	if (inodeno == -1) {
569 		printf("no inode left to assign\n");
570 		goto fail;
571 	}
572 	dir->inode = cpu_to_le32(inodeno);
573 	if (sizeof_void_space)
574 		dir->direntlen = cpu_to_le16(sizeof_void_space);
575 	else
576 		dir->direntlen = cpu_to_le16(fs->blksz - totalbytes);
577 
578 	dir->namelen = strlen(filename);
579 	dir->filetype = FILETYPE_REG;	/* regular file */
580 	temp_dir = (char *)dir;
581 	temp_dir = temp_dir + sizeof(struct ext2_dirent);
582 	memcpy(temp_dir, filename, strlen(filename));
583 
584 	/* update or write  the 1st block of root inode */
585 	if (ext4fs_put_metadata(root_first_block_buffer,
586 				first_block_no_of_root))
587 		goto fail;
588 
589 fail:
590 	free(zero_buffer);
591 	free(root_first_block_buffer);
592 
593 	return inodeno;
594 }
595 
596 static int search_dir(struct ext2_inode *parent_inode, char *dirname)
597 {
598 	int status;
599 	int inodeno = 0;
600 	int offset;
601 	int blk_idx;
602 	long int blknr;
603 	char *block_buffer = NULL;
604 	struct ext2_dirent *dir = NULL;
605 	struct ext_filesystem *fs = get_fs();
606 	uint32_t directory_blocks;
607 	char *direntname;
608 
609 	directory_blocks = le32_to_cpu(parent_inode->size) >>
610 		LOG2_BLOCK_SIZE(ext4fs_root);
611 
612 	block_buffer = zalloc(fs->blksz);
613 	if (!block_buffer)
614 		goto fail;
615 
616 	/* get the block no allocated to a file */
617 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
618 		blknr = read_allocated_block(parent_inode, blk_idx);
619 		if (blknr <= 0)
620 			goto fail;
621 
622 		/* read the directory block */
623 		status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk,
624 					0, fs->blksz, (char *)block_buffer);
625 		if (status == 0)
626 			goto fail;
627 
628 		offset = 0;
629 		do {
630 			dir = (struct ext2_dirent *)(block_buffer + offset);
631 			direntname = (char*)(dir) + sizeof(struct ext2_dirent);
632 
633 			int direntlen = le16_to_cpu(dir->direntlen);
634 			if (direntlen < sizeof(struct ext2_dirent))
635 				break;
636 
637 			if (dir->inode && (strlen(dirname) == dir->namelen) &&
638 			    (strncmp(dirname, direntname, dir->namelen) == 0)) {
639 				inodeno = le32_to_cpu(dir->inode);
640 				break;
641 			}
642 
643 			offset += direntlen;
644 
645 		} while (offset < fs->blksz);
646 
647 		if (inodeno > 0) {
648 			free(block_buffer);
649 			return inodeno;
650 		}
651 	}
652 
653 fail:
654 	free(block_buffer);
655 
656 	return -1;
657 }
658 
659 static int find_dir_depth(char *dirname)
660 {
661 	char *token = strtok(dirname, "/");
662 	int count = 0;
663 	while (token != NULL) {
664 		token = strtok(NULL, "/");
665 		count++;
666 	}
667 	return count + 1 + 1;
668 	/*
669 	 * for example  for string /home/temp
670 	 * depth=home(1)+temp(1)+1 extra for NULL;
671 	 * so count is 4;
672 	 */
673 }
674 
675 static int parse_path(char **arr, char *dirname)
676 {
677 	char *token = strtok(dirname, "/");
678 	int i = 0;
679 
680 	/* add root */
681 	arr[i] = zalloc(strlen("/") + 1);
682 	if (!arr[i])
683 		return -ENOMEM;
684 	memcpy(arr[i++], "/", strlen("/"));
685 
686 	/* add each path entry after root */
687 	while (token != NULL) {
688 		arr[i] = zalloc(strlen(token) + 1);
689 		if (!arr[i])
690 			return -ENOMEM;
691 		memcpy(arr[i++], token, strlen(token));
692 		token = strtok(NULL, "/");
693 	}
694 	arr[i] = NULL;
695 
696 	return 0;
697 }
698 
699 int ext4fs_iget(int inode_no, struct ext2_inode *inode)
700 {
701 	if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0)
702 		return -1;
703 
704 	return 0;
705 }
706 
707 /*
708  * Function: ext4fs_get_parent_inode_num
709  * Return Value: inode Number of the parent directory of  file/Directory to be
710  * created
711  * dirname : Input parmater, input path name of the file/directory to be created
712  * dname : Output parameter, to be filled with the name of the directory
713  * extracted from dirname
714  */
715 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags)
716 {
717 	int i;
718 	int depth = 0;
719 	int matched_inode_no;
720 	int result_inode_no = -1;
721 	char **ptr = NULL;
722 	char *depth_dirname = NULL;
723 	char *parse_dirname = NULL;
724 	struct ext2_inode *parent_inode = NULL;
725 	struct ext2_inode *first_inode = NULL;
726 	struct ext2_inode temp_inode;
727 
728 	if (*dirname != '/') {
729 		printf("Please supply Absolute path\n");
730 		return -1;
731 	}
732 
733 	/* TODO: input validation make equivalent to linux */
734 	depth_dirname = zalloc(strlen(dirname) + 1);
735 	if (!depth_dirname)
736 		return -ENOMEM;
737 
738 	memcpy(depth_dirname, dirname, strlen(dirname));
739 	depth = find_dir_depth(depth_dirname);
740 	parse_dirname = zalloc(strlen(dirname) + 1);
741 	if (!parse_dirname)
742 		goto fail;
743 	memcpy(parse_dirname, dirname, strlen(dirname));
744 
745 	/* allocate memory for each directory level */
746 	ptr = zalloc((depth) * sizeof(char *));
747 	if (!ptr)
748 		goto fail;
749 	if (parse_path(ptr, parse_dirname))
750 		goto fail;
751 	parent_inode = zalloc(sizeof(struct ext2_inode));
752 	if (!parent_inode)
753 		goto fail;
754 	first_inode = zalloc(sizeof(struct ext2_inode));
755 	if (!first_inode)
756 		goto fail;
757 	memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode));
758 	memcpy(first_inode, parent_inode, sizeof(struct ext2_inode));
759 	if (flags & F_FILE)
760 		result_inode_no = EXT2_ROOT_INO;
761 	for (i = 1; i < depth; i++) {
762 		matched_inode_no = search_dir(parent_inode, ptr[i]);
763 		if (matched_inode_no == -1) {
764 			if (ptr[i + 1] == NULL && i == 1) {
765 				result_inode_no = EXT2_ROOT_INO;
766 				goto end;
767 			} else {
768 				if (ptr[i + 1] == NULL)
769 					break;
770 				printf("Invalid path\n");
771 				result_inode_no = -1;
772 				goto fail;
773 			}
774 		} else {
775 			if (ptr[i + 1] != NULL) {
776 				memset(parent_inode, '\0',
777 				       sizeof(struct ext2_inode));
778 				if (ext4fs_iget(matched_inode_no,
779 						parent_inode)) {
780 					result_inode_no = -1;
781 					goto fail;
782 				}
783 				result_inode_no = matched_inode_no;
784 			} else {
785 				break;
786 			}
787 		}
788 	}
789 
790 end:
791 	if (i == 1)
792 		matched_inode_no = search_dir(first_inode, ptr[i]);
793 	else
794 		matched_inode_no = search_dir(parent_inode, ptr[i]);
795 
796 	if (matched_inode_no != -1) {
797 		ext4fs_iget(matched_inode_no, &temp_inode);
798 		if (le16_to_cpu(temp_inode.mode) & S_IFDIR) {
799 			printf("It is a Directory\n");
800 			result_inode_no = -1;
801 			goto fail;
802 		}
803 	}
804 
805 	if (strlen(ptr[i]) > 256) {
806 		result_inode_no = -1;
807 		goto fail;
808 	}
809 	memcpy(dname, ptr[i], strlen(ptr[i]));
810 
811 fail:
812 	free(depth_dirname);
813 	free(parse_dirname);
814 	for (i = 0; i < depth; i++) {
815 		if (!ptr[i])
816 			break;
817 		free(ptr[i]);
818 	}
819 	free(ptr);
820 	free(parent_inode);
821 	free(first_inode);
822 
823 	return result_inode_no;
824 }
825 
826 static int unlink_filename(char *filename, unsigned int blknr)
827 {
828 	int totalbytes = 0;
829 	int templength = 0;
830 	int status, inodeno;
831 	int found = 0;
832 	char *root_first_block_buffer = NULL;
833 	struct ext2_dirent *dir = NULL;
834 	struct ext2_dirent *previous_dir = NULL;
835 	char *ptr = NULL;
836 	struct ext_filesystem *fs = get_fs();
837 	int ret = -1;
838 
839 	/* get the first block of root */
840 	root_first_block_buffer = zalloc(fs->blksz);
841 	if (!root_first_block_buffer)
842 		return -ENOMEM;
843 	status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0,
844 				fs->blksz, root_first_block_buffer);
845 	if (status == 0)
846 		goto fail;
847 
848 	if (ext4fs_log_journal(root_first_block_buffer, blknr))
849 		goto fail;
850 	dir = (struct ext2_dirent *)root_first_block_buffer;
851 	ptr = (char *)dir;
852 	totalbytes = 0;
853 	while (le16_to_cpu(dir->direntlen) >= 0) {
854 		/*
855 		 * blocksize-totalbytes because last
856 		 * directory length i.e., *dir->direntlen
857 		 * is free availble space in the block that
858 		 * means it is a last entry of directory entry
859 		 */
860 		if (dir->inode && (strlen(filename) == dir->namelen) &&
861 		    (strncmp(ptr + sizeof(struct ext2_dirent),
862 			     filename, dir->namelen) == 0)) {
863 			printf("file found, deleting\n");
864 			inodeno = le32_to_cpu(dir->inode);
865 			if (previous_dir) {
866 				uint16_t new_len;
867 				new_len = le16_to_cpu(previous_dir->direntlen);
868 				new_len += le16_to_cpu(dir->direntlen);
869 				previous_dir->direntlen = cpu_to_le16(new_len);
870 			} else {
871 				dir->inode = 0;
872 			}
873 			found = 1;
874 			break;
875 		}
876 
877 		if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen))
878 			break;
879 
880 		/* traversing the each directory entry */
881 		templength = le16_to_cpu(dir->direntlen);
882 		totalbytes = totalbytes + templength;
883 		previous_dir = dir;
884 		dir = (struct ext2_dirent *)((char *)dir + templength);
885 		ptr = (char *)dir;
886 	}
887 
888 
889 	if (found == 1) {
890 		if (ext4fs_put_metadata(root_first_block_buffer, blknr))
891 			goto fail;
892 		ret = inodeno;
893 	}
894 fail:
895 	free(root_first_block_buffer);
896 
897 	return ret;
898 }
899 
900 int ext4fs_filename_unlink(char *filename)
901 {
902 	int blk_idx;
903 	long int blknr = -1;
904 	int inodeno = -1;
905 	uint32_t directory_blocks;
906 
907 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
908 		LOG2_BLOCK_SIZE(ext4fs_root);
909 
910 	/* read the block no allocated to a file */
911 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
912 		blknr = read_allocated_block(g_parent_inode, blk_idx);
913 		if (blknr <= 0)
914 			break;
915 		inodeno = unlink_filename(filename, blknr);
916 		if (inodeno != -1)
917 			return inodeno;
918 	}
919 
920 	return -1;
921 }
922 
923 uint32_t ext4fs_get_new_blk_no(void)
924 {
925 	short i;
926 	short status;
927 	int remainder;
928 	unsigned int bg_idx;
929 	static int prev_bg_bitmap_index = -1;
930 	unsigned int blk_per_grp = le32_to_cpu(ext4fs_root->sblock.blocks_per_group);
931 	struct ext_filesystem *fs = get_fs();
932 	char *journal_buffer = zalloc(fs->blksz);
933 	char *zero_buffer = zalloc(fs->blksz);
934 	if (!journal_buffer || !zero_buffer)
935 		goto fail;
936 	struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable;
937 
938 	if (fs->first_pass_bbmap == 0) {
939 		for (i = 0; i < fs->no_blkgrp; i++) {
940 			if (le16_to_cpu(bgd[i].free_blocks)) {
941 				if (le16_to_cpu(bgd[i].bg_flags) & EXT4_BG_BLOCK_UNINIT) {
942 					uint16_t new_flags;
943 					put_ext4((uint64_t)le32_to_cpu(bgd[i].block_id) * fs->blksz,
944 						 zero_buffer, fs->blksz);
945 					new_flags = le16_to_cpu(bgd[i].bg_flags) & ~EXT4_BG_BLOCK_UNINIT;
946 					bgd[i].bg_flags = cpu_to_le16(new_flags);
947 					memcpy(fs->blk_bmaps[i], zero_buffer,
948 					       fs->blksz);
949 				}
950 				fs->curr_blkno =
951 				    _get_new_blk_no(fs->blk_bmaps[i]);
952 				if (fs->curr_blkno == -1)
953 					/* if block bitmap is completely fill */
954 					continue;
955 				fs->curr_blkno = fs->curr_blkno +
956 						(i * fs->blksz * 8);
957 				fs->first_pass_bbmap++;
958 				ext4fs_bg_free_blocks_dec(&bgd[i]);
959 				ext4fs_sb_free_blocks_dec(fs->sb);
960 				status = ext4fs_devread(
961 							(lbaint_t)le32_to_cpu(bgd[i].block_id) *
962 							fs->sect_perblk, 0,
963 							fs->blksz,
964 							journal_buffer);
965 				if (status == 0)
966 					goto fail;
967 				if (ext4fs_log_journal(journal_buffer,
968 							le32_to_cpu(bgd[i].block_id)))
969 					goto fail;
970 				goto success;
971 			} else {
972 				debug("no space left on block group %d\n", i);
973 			}
974 		}
975 
976 		goto fail;
977 	} else {
978 		fs->curr_blkno++;
979 restart:
980 		/* get the blockbitmap index respective to blockno */
981 		bg_idx = fs->curr_blkno / blk_per_grp;
982 		if (fs->blksz == 1024) {
983 			remainder = fs->curr_blkno % blk_per_grp;
984 			if (!remainder)
985 				bg_idx--;
986 		}
987 
988 		/*
989 		 * To skip completely filled block group bitmaps
990 		 * Optimize the block allocation
991 		 */
992 		if (bg_idx >= fs->no_blkgrp)
993 			goto fail;
994 
995 		if (bgd[bg_idx].free_blocks == 0) {
996 			debug("block group %u is full. Skipping\n", bg_idx);
997 			fs->curr_blkno = (bg_idx + 1) * blk_per_grp;
998 			if (fs->blksz == 1024)
999 				fs->curr_blkno += 1;
1000 			goto restart;
1001 		}
1002 
1003 		if (le16_to_cpu(bgd[bg_idx].bg_flags) & EXT4_BG_BLOCK_UNINIT) {
1004 			uint16_t new_flags;
1005 			put_ext4((uint64_t)le32_to_cpu(bgd[bg_idx].block_id) * fs->blksz,
1006 				 zero_buffer, fs->blksz);
1007 			memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz);
1008 			new_flags = le16_to_cpu(bgd[bg_idx].bg_flags) & ~EXT4_BG_BLOCK_UNINIT;
1009 			bgd[bg_idx].bg_flags = cpu_to_le16(new_flags);
1010 		}
1011 
1012 		if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx],
1013 				   bg_idx) != 0) {
1014 			debug("going for restart for the block no %ld %u\n",
1015 			      fs->curr_blkno, bg_idx);
1016 			fs->curr_blkno++;
1017 			goto restart;
1018 		}
1019 
1020 		/* journal backup */
1021 		if (prev_bg_bitmap_index != bg_idx) {
1022 			status = ext4fs_devread(
1023 						(lbaint_t)le32_to_cpu(bgd[bg_idx].block_id)
1024 						* fs->sect_perblk,
1025 						0, fs->blksz, journal_buffer);
1026 			if (status == 0)
1027 				goto fail;
1028 			if (ext4fs_log_journal(journal_buffer,
1029 						le32_to_cpu(bgd[bg_idx].block_id)))
1030 				goto fail;
1031 
1032 			prev_bg_bitmap_index = bg_idx;
1033 		}
1034 		ext4fs_bg_free_blocks_dec(&bgd[bg_idx]);
1035 		ext4fs_sb_free_blocks_dec(fs->sb);
1036 		goto success;
1037 	}
1038 success:
1039 	free(journal_buffer);
1040 	free(zero_buffer);
1041 
1042 	return fs->curr_blkno;
1043 fail:
1044 	free(journal_buffer);
1045 	free(zero_buffer);
1046 
1047 	return -1;
1048 }
1049 
1050 int ext4fs_get_new_inode_no(void)
1051 {
1052 	short i;
1053 	short status;
1054 	unsigned int ibmap_idx;
1055 	static int prev_inode_bitmap_index = -1;
1056 	unsigned int inodes_per_grp = le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
1057 	struct ext_filesystem *fs = get_fs();
1058 	char *journal_buffer = zalloc(fs->blksz);
1059 	char *zero_buffer = zalloc(fs->blksz);
1060 	if (!journal_buffer || !zero_buffer)
1061 		goto fail;
1062 	struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable;
1063 	int has_gdt_chksum = le32_to_cpu(fs->sb->feature_ro_compat) &
1064 		EXT4_FEATURE_RO_COMPAT_GDT_CSUM ? 1 : 0;
1065 
1066 	if (fs->first_pass_ibmap == 0) {
1067 		for (i = 0; i < fs->no_blkgrp; i++) {
1068 			if (bgd[i].free_inodes) {
1069 				if (has_gdt_chksum)
1070 					bgd[i].bg_itable_unused =
1071 						bgd[i].free_inodes;
1072 				if (le16_to_cpu(bgd[i].bg_flags) & EXT4_BG_INODE_UNINIT) {
1073 					int new_flags;
1074 					put_ext4((uint64_t)le32_to_cpu(bgd[i].inode_id) * fs->blksz,
1075 						 zero_buffer, fs->blksz);
1076 					new_flags = le16_to_cpu(bgd[i].bg_flags) & ~EXT4_BG_INODE_UNINIT;
1077 					bgd[i].bg_flags = cpu_to_le16(new_flags);
1078 					memcpy(fs->inode_bmaps[i],
1079 					       zero_buffer, fs->blksz);
1080 				}
1081 				fs->curr_inode_no =
1082 				    _get_new_inode_no(fs->inode_bmaps[i]);
1083 				if (fs->curr_inode_no == -1)
1084 					/* if block bitmap is completely fill */
1085 					continue;
1086 				fs->curr_inode_no = fs->curr_inode_no +
1087 							(i * inodes_per_grp);
1088 				fs->first_pass_ibmap++;
1089 				ext4fs_bg_free_inodes_dec(&bgd[i]);
1090 				if (has_gdt_chksum)
1091 					ext4fs_bg_itable_unused_dec(&bgd[i]);
1092 				ext4fs_sb_free_inodes_dec(fs->sb);
1093 				status = ext4fs_devread(
1094 							(lbaint_t)le32_to_cpu(bgd[i].inode_id) *
1095 							fs->sect_perblk, 0,
1096 							fs->blksz,
1097 							journal_buffer);
1098 				if (status == 0)
1099 					goto fail;
1100 				if (ext4fs_log_journal(journal_buffer,
1101 							le32_to_cpu(bgd[i].inode_id)))
1102 					goto fail;
1103 				goto success;
1104 			} else
1105 				debug("no inode left on block group %d\n", i);
1106 		}
1107 		goto fail;
1108 	} else {
1109 restart:
1110 		fs->curr_inode_no++;
1111 		/* get the blockbitmap index respective to blockno */
1112 		ibmap_idx = fs->curr_inode_no / inodes_per_grp;
1113 		if (le16_to_cpu(bgd[ibmap_idx].bg_flags) & EXT4_BG_INODE_UNINIT) {
1114 			int new_flags;
1115 			put_ext4((uint64_t)le32_to_cpu(bgd[ibmap_idx].inode_id) * fs->blksz,
1116 				 zero_buffer, fs->blksz);
1117 			new_flags = le16_to_cpu(bgd[ibmap_idx].bg_flags) & ~EXT4_BG_INODE_UNINIT;
1118 			bgd[ibmap_idx].bg_flags = cpu_to_le16(new_flags);
1119 			memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer,
1120 				fs->blksz);
1121 		}
1122 
1123 		if (ext4fs_set_inode_bmap(fs->curr_inode_no,
1124 					  fs->inode_bmaps[ibmap_idx],
1125 					  ibmap_idx) != 0) {
1126 			debug("going for restart for the block no %d %u\n",
1127 			      fs->curr_inode_no, ibmap_idx);
1128 			goto restart;
1129 		}
1130 
1131 		/* journal backup */
1132 		if (prev_inode_bitmap_index != ibmap_idx) {
1133 			memset(journal_buffer, '\0', fs->blksz);
1134 			status = ext4fs_devread(
1135 						(lbaint_t)le32_to_cpu(bgd[ibmap_idx].inode_id)
1136 						* fs->sect_perblk,
1137 						0, fs->blksz, journal_buffer);
1138 			if (status == 0)
1139 				goto fail;
1140 			if (ext4fs_log_journal(journal_buffer,
1141 						le32_to_cpu(bgd[ibmap_idx].inode_id)))
1142 				goto fail;
1143 			prev_inode_bitmap_index = ibmap_idx;
1144 		}
1145 		ext4fs_bg_free_inodes_dec(&bgd[ibmap_idx]);
1146 		if (has_gdt_chksum)
1147 			bgd[ibmap_idx].bg_itable_unused =
1148 					bgd[ibmap_idx].free_inodes;
1149 		ext4fs_sb_free_inodes_dec(fs->sb);
1150 		goto success;
1151 	}
1152 
1153 success:
1154 	free(journal_buffer);
1155 	free(zero_buffer);
1156 
1157 	return fs->curr_inode_no;
1158 fail:
1159 	free(journal_buffer);
1160 	free(zero_buffer);
1161 
1162 	return -1;
1163 
1164 }
1165 
1166 
1167 static void alloc_single_indirect_block(struct ext2_inode *file_inode,
1168 					unsigned int *total_remaining_blocks,
1169 					unsigned int *no_blks_reqd)
1170 {
1171 	short i;
1172 	short status;
1173 	long int actual_block_no;
1174 	long int si_blockno;
1175 	/* si :single indirect */
1176 	__le32 *si_buffer = NULL;
1177 	__le32 *si_start_addr = NULL;
1178 	struct ext_filesystem *fs = get_fs();
1179 
1180 	if (*total_remaining_blocks != 0) {
1181 		si_buffer = zalloc(fs->blksz);
1182 		if (!si_buffer) {
1183 			printf("No Memory\n");
1184 			return;
1185 		}
1186 		si_start_addr = si_buffer;
1187 		si_blockno = ext4fs_get_new_blk_no();
1188 		if (si_blockno == -1) {
1189 			printf("no block left to assign\n");
1190 			goto fail;
1191 		}
1192 		(*no_blks_reqd)++;
1193 		debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks);
1194 
1195 		status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk,
1196 					0, fs->blksz, (char *)si_buffer);
1197 		memset(si_buffer, '\0', fs->blksz);
1198 		if (status == 0)
1199 			goto fail;
1200 
1201 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1202 			actual_block_no = ext4fs_get_new_blk_no();
1203 			if (actual_block_no == -1) {
1204 				printf("no block left to assign\n");
1205 				goto fail;
1206 			}
1207 			*si_buffer = cpu_to_le32(actual_block_no);
1208 			debug("SIAB %u: %u\n", *si_buffer,
1209 				*total_remaining_blocks);
1210 
1211 			si_buffer++;
1212 			(*total_remaining_blocks)--;
1213 			if (*total_remaining_blocks == 0)
1214 				break;
1215 		}
1216 
1217 		/* write the block to disk */
1218 		put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)),
1219 			 si_start_addr, fs->blksz);
1220 		file_inode->b.blocks.indir_block = cpu_to_le32(si_blockno);
1221 	}
1222 fail:
1223 	free(si_start_addr);
1224 }
1225 
1226 static void alloc_double_indirect_block(struct ext2_inode *file_inode,
1227 					unsigned int *total_remaining_blocks,
1228 					unsigned int *no_blks_reqd)
1229 {
1230 	short i;
1231 	short j;
1232 	short status;
1233 	long int actual_block_no;
1234 	/* di:double indirect */
1235 	long int di_blockno_parent;
1236 	long int di_blockno_child;
1237 	__le32 *di_parent_buffer = NULL;
1238 	__le32 *di_child_buff = NULL;
1239 	__le32 *di_block_start_addr = NULL;
1240 	__le32 *di_child_buff_start = NULL;
1241 	struct ext_filesystem *fs = get_fs();
1242 
1243 	if (*total_remaining_blocks != 0) {
1244 		/* double indirect parent block connecting to inode */
1245 		di_blockno_parent = ext4fs_get_new_blk_no();
1246 		if (di_blockno_parent == -1) {
1247 			printf("no block left to assign\n");
1248 			goto fail;
1249 		}
1250 		di_parent_buffer = zalloc(fs->blksz);
1251 		if (!di_parent_buffer)
1252 			goto fail;
1253 
1254 		di_block_start_addr = di_parent_buffer;
1255 		(*no_blks_reqd)++;
1256 		debug("DIPB %ld: %u\n", di_blockno_parent,
1257 		      *total_remaining_blocks);
1258 
1259 		status = ext4fs_devread((lbaint_t)di_blockno_parent *
1260 					fs->sect_perblk, 0,
1261 					fs->blksz, (char *)di_parent_buffer);
1262 
1263 		if (!status) {
1264 			printf("%s: Device read error!\n", __func__);
1265 			goto fail;
1266 		}
1267 		memset(di_parent_buffer, '\0', fs->blksz);
1268 
1269 		/*
1270 		 * start:for each double indirect parent
1271 		 * block create one more block
1272 		 */
1273 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1274 			di_blockno_child = ext4fs_get_new_blk_no();
1275 			if (di_blockno_child == -1) {
1276 				printf("no block left to assign\n");
1277 				goto fail;
1278 			}
1279 			di_child_buff = zalloc(fs->blksz);
1280 			if (!di_child_buff)
1281 				goto fail;
1282 
1283 			di_child_buff_start = di_child_buff;
1284 			*di_parent_buffer = cpu_to_le32(di_blockno_child);
1285 			di_parent_buffer++;
1286 			(*no_blks_reqd)++;
1287 			debug("DICB %ld: %u\n", di_blockno_child,
1288 			      *total_remaining_blocks);
1289 
1290 			status = ext4fs_devread((lbaint_t)di_blockno_child *
1291 						fs->sect_perblk, 0,
1292 						fs->blksz,
1293 						(char *)di_child_buff);
1294 
1295 			if (!status) {
1296 				printf("%s: Device read error!\n", __func__);
1297 				goto fail;
1298 			}
1299 			memset(di_child_buff, '\0', fs->blksz);
1300 			/* filling of actual datablocks for each child */
1301 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1302 				actual_block_no = ext4fs_get_new_blk_no();
1303 				if (actual_block_no == -1) {
1304 					printf("no block left to assign\n");
1305 					goto fail;
1306 				}
1307 				*di_child_buff = cpu_to_le32(actual_block_no);
1308 				debug("DIAB %ld: %u\n", actual_block_no,
1309 				      *total_remaining_blocks);
1310 
1311 				di_child_buff++;
1312 				(*total_remaining_blocks)--;
1313 				if (*total_remaining_blocks == 0)
1314 					break;
1315 			}
1316 			/* write the block  table */
1317 			put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)),
1318 				 di_child_buff_start, fs->blksz);
1319 			free(di_child_buff_start);
1320 			di_child_buff_start = NULL;
1321 
1322 			if (*total_remaining_blocks == 0)
1323 				break;
1324 		}
1325 		put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)),
1326 			 di_block_start_addr, fs->blksz);
1327 		file_inode->b.blocks.double_indir_block = cpu_to_le32(di_blockno_parent);
1328 	}
1329 fail:
1330 	free(di_block_start_addr);
1331 }
1332 
1333 static void alloc_triple_indirect_block(struct ext2_inode *file_inode,
1334 					unsigned int *total_remaining_blocks,
1335 					unsigned int *no_blks_reqd)
1336 {
1337 	short i;
1338 	short j;
1339 	short k;
1340 	long int actual_block_no;
1341 	/* ti: Triple Indirect */
1342 	long int ti_gp_blockno;
1343 	long int ti_parent_blockno;
1344 	long int ti_child_blockno;
1345 	__le32 *ti_gp_buff = NULL;
1346 	__le32 *ti_parent_buff = NULL;
1347 	__le32 *ti_child_buff = NULL;
1348 	__le32 *ti_gp_buff_start_addr = NULL;
1349 	__le32 *ti_pbuff_start_addr = NULL;
1350 	__le32 *ti_cbuff_start_addr = NULL;
1351 	struct ext_filesystem *fs = get_fs();
1352 	if (*total_remaining_blocks != 0) {
1353 		/* triple indirect grand parent block connecting to inode */
1354 		ti_gp_blockno = ext4fs_get_new_blk_no();
1355 		if (ti_gp_blockno == -1) {
1356 			printf("no block left to assign\n");
1357 			return;
1358 		}
1359 		ti_gp_buff = zalloc(fs->blksz);
1360 		if (!ti_gp_buff)
1361 			return;
1362 
1363 		ti_gp_buff_start_addr = ti_gp_buff;
1364 		(*no_blks_reqd)++;
1365 		debug("TIGPB %ld: %u\n", ti_gp_blockno,
1366 		      *total_remaining_blocks);
1367 
1368 		/* for each 4 byte grand parent entry create one more block */
1369 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1370 			ti_parent_blockno = ext4fs_get_new_blk_no();
1371 			if (ti_parent_blockno == -1) {
1372 				printf("no block left to assign\n");
1373 				goto fail;
1374 			}
1375 			ti_parent_buff = zalloc(fs->blksz);
1376 			if (!ti_parent_buff)
1377 				goto fail;
1378 
1379 			ti_pbuff_start_addr = ti_parent_buff;
1380 			*ti_gp_buff = cpu_to_le32(ti_parent_blockno);
1381 			ti_gp_buff++;
1382 			(*no_blks_reqd)++;
1383 			debug("TIPB %ld: %u\n", ti_parent_blockno,
1384 			      *total_remaining_blocks);
1385 
1386 			/* for each 4 byte entry parent create one more block */
1387 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1388 				ti_child_blockno = ext4fs_get_new_blk_no();
1389 				if (ti_child_blockno == -1) {
1390 					printf("no block left assign\n");
1391 					goto fail1;
1392 				}
1393 				ti_child_buff = zalloc(fs->blksz);
1394 				if (!ti_child_buff)
1395 					goto fail1;
1396 
1397 				ti_cbuff_start_addr = ti_child_buff;
1398 				*ti_parent_buff = cpu_to_le32(ti_child_blockno);
1399 				ti_parent_buff++;
1400 				(*no_blks_reqd)++;
1401 				debug("TICB %ld: %u\n", ti_parent_blockno,
1402 				      *total_remaining_blocks);
1403 
1404 				/* fill actual datablocks for each child */
1405 				for (k = 0; k < (fs->blksz / sizeof(int));
1406 					k++) {
1407 					actual_block_no =
1408 					    ext4fs_get_new_blk_no();
1409 					if (actual_block_no == -1) {
1410 						printf("no block left\n");
1411 						free(ti_cbuff_start_addr);
1412 						goto fail1;
1413 					}
1414 					*ti_child_buff = cpu_to_le32(actual_block_no);
1415 					debug("TIAB %ld: %u\n", actual_block_no,
1416 					      *total_remaining_blocks);
1417 
1418 					ti_child_buff++;
1419 					(*total_remaining_blocks)--;
1420 					if (*total_remaining_blocks == 0)
1421 						break;
1422 				}
1423 				/* write the child block */
1424 				put_ext4(((uint64_t) ((uint64_t)ti_child_blockno *
1425 						      (uint64_t)fs->blksz)),
1426 					 ti_cbuff_start_addr, fs->blksz);
1427 				free(ti_cbuff_start_addr);
1428 
1429 				if (*total_remaining_blocks == 0)
1430 					break;
1431 			}
1432 			/* write the parent block */
1433 			put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)),
1434 				 ti_pbuff_start_addr, fs->blksz);
1435 			free(ti_pbuff_start_addr);
1436 
1437 			if (*total_remaining_blocks == 0)
1438 				break;
1439 		}
1440 		/* write the grand parent block */
1441 		put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)),
1442 			 ti_gp_buff_start_addr, fs->blksz);
1443 		file_inode->b.blocks.triple_indir_block = cpu_to_le32(ti_gp_blockno);
1444 		free(ti_gp_buff_start_addr);
1445 		return;
1446 	}
1447 fail1:
1448 	free(ti_pbuff_start_addr);
1449 fail:
1450 	free(ti_gp_buff_start_addr);
1451 }
1452 
1453 void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
1454 				unsigned int total_remaining_blocks,
1455 				unsigned int *total_no_of_block)
1456 {
1457 	short i;
1458 	long int direct_blockno;
1459 	unsigned int no_blks_reqd = 0;
1460 
1461 	/* allocation of direct blocks */
1462 	for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) {
1463 		direct_blockno = ext4fs_get_new_blk_no();
1464 		if (direct_blockno == -1) {
1465 			printf("no block left to assign\n");
1466 			return;
1467 		}
1468 		file_inode->b.blocks.dir_blocks[i] = cpu_to_le32(direct_blockno);
1469 		debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);
1470 
1471 		total_remaining_blocks--;
1472 	}
1473 
1474 	alloc_single_indirect_block(file_inode, &total_remaining_blocks,
1475 				    &no_blks_reqd);
1476 	alloc_double_indirect_block(file_inode, &total_remaining_blocks,
1477 				    &no_blks_reqd);
1478 	alloc_triple_indirect_block(file_inode, &total_remaining_blocks,
1479 				    &no_blks_reqd);
1480 	*total_no_of_block += no_blks_reqd;
1481 }
1482 
1483 #endif
1484 
1485 static struct ext4_extent_header *ext4fs_get_extent_block
1486 	(struct ext2_data *data, char *buf,
1487 		struct ext4_extent_header *ext_block,
1488 		uint32_t fileblock, int log2_blksz)
1489 {
1490 	struct ext4_extent_idx *index;
1491 	unsigned long long block;
1492 	int blksz = EXT2_BLOCK_SIZE(data);
1493 	int i;
1494 
1495 	while (1) {
1496 		index = (struct ext4_extent_idx *)(ext_block + 1);
1497 
1498 		if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
1499 			return NULL;
1500 
1501 		if (ext_block->eh_depth == 0)
1502 			return ext_block;
1503 		i = -1;
1504 		do {
1505 			i++;
1506 			if (i >= le16_to_cpu(ext_block->eh_entries))
1507 				break;
1508 		} while (fileblock >= le32_to_cpu(index[i].ei_block));
1509 
1510 		if (--i < 0)
1511 			return NULL;
1512 
1513 		block = le16_to_cpu(index[i].ei_leaf_hi);
1514 		block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
1515 
1516 		if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz,
1517 				   buf))
1518 			ext_block = (struct ext4_extent_header *)buf;
1519 		else
1520 			return NULL;
1521 	}
1522 }
1523 
1524 static int ext4fs_blockgroup
1525 	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
1526 {
1527 	long int blkno;
1528 	unsigned int blkoff, desc_per_blk;
1529 	int log2blksz = get_fs()->dev_desc->log2blksz;
1530 
1531 	desc_per_blk = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group);
1532 
1533 	blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
1534 			group / desc_per_blk;
1535 	blkoff = (group % desc_per_blk) * sizeof(struct ext2_block_group);
1536 
1537 	debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
1538 	      group, blkno, blkoff);
1539 
1540 	return ext4fs_devread((lbaint_t)blkno <<
1541 			      (LOG2_BLOCK_SIZE(data) - log2blksz),
1542 			      blkoff, sizeof(struct ext2_block_group),
1543 			      (char *)blkgrp);
1544 }
1545 
1546 int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
1547 {
1548 	struct ext2_block_group blkgrp;
1549 	struct ext2_sblock *sblock = &data->sblock;
1550 	struct ext_filesystem *fs = get_fs();
1551 	int log2blksz = get_fs()->dev_desc->log2blksz;
1552 	int inodes_per_block, status;
1553 	long int blkno;
1554 	unsigned int blkoff;
1555 
1556 	/* It is easier to calculate if the first inode is 0. */
1557 	ino--;
1558 	status = ext4fs_blockgroup(data, ino / le32_to_cpu
1559 				   (sblock->inodes_per_group), &blkgrp);
1560 	if (status == 0)
1561 		return 0;
1562 
1563 	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
1564 	blkno = le32_to_cpu(blkgrp.inode_table_id) +
1565 	    (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1566 	blkoff = (ino % inodes_per_block) * fs->inodesz;
1567 	/* Read the inode. */
1568 	status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) -
1569 				log2blksz), blkoff,
1570 				sizeof(struct ext2_inode), (char *)inode);
1571 	if (status == 0)
1572 		return 0;
1573 
1574 	return 1;
1575 }
1576 
1577 long int read_allocated_block(struct ext2_inode *inode, int fileblock)
1578 {
1579 	long int blknr;
1580 	int blksz;
1581 	int log2_blksz;
1582 	int status;
1583 	long int rblock;
1584 	long int perblock_parent;
1585 	long int perblock_child;
1586 	unsigned long long start;
1587 	/* get the blocksize of the filesystem */
1588 	blksz = EXT2_BLOCK_SIZE(ext4fs_root);
1589 	log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
1590 		- get_fs()->dev_desc->log2blksz;
1591 
1592 	if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
1593 		char *buf = zalloc(blksz);
1594 		if (!buf)
1595 			return -ENOMEM;
1596 		struct ext4_extent_header *ext_block;
1597 		struct ext4_extent *extent;
1598 		int i = -1;
1599 		ext_block =
1600 			ext4fs_get_extent_block(ext4fs_root, buf,
1601 						(struct ext4_extent_header *)
1602 						inode->b.blocks.dir_blocks,
1603 						fileblock, log2_blksz);
1604 		if (!ext_block) {
1605 			printf("invalid extent block\n");
1606 			free(buf);
1607 			return -EINVAL;
1608 		}
1609 
1610 		extent = (struct ext4_extent *)(ext_block + 1);
1611 
1612 		do {
1613 			i++;
1614 			if (i >= le16_to_cpu(ext_block->eh_entries))
1615 				break;
1616 		} while (fileblock >= le32_to_cpu(extent[i].ee_block));
1617 		if (--i >= 0) {
1618 			fileblock -= le32_to_cpu(extent[i].ee_block);
1619 			if (fileblock >= le16_to_cpu(extent[i].ee_len)) {
1620 				free(buf);
1621 				return 0;
1622 			}
1623 
1624 			start = le16_to_cpu(extent[i].ee_start_hi);
1625 			start = (start << 32) +
1626 					le32_to_cpu(extent[i].ee_start_lo);
1627 			free(buf);
1628 			return fileblock + start;
1629 		}
1630 
1631 		printf("Extent Error\n");
1632 		free(buf);
1633 		return -1;
1634 	}
1635 
1636 	/* Direct blocks. */
1637 	if (fileblock < INDIRECT_BLOCKS)
1638 		blknr = le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
1639 
1640 	/* Indirect. */
1641 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
1642 		if (ext4fs_indir1_block == NULL) {
1643 			ext4fs_indir1_block = zalloc(blksz);
1644 			if (ext4fs_indir1_block == NULL) {
1645 				printf("** SI ext2fs read block (indir 1)"
1646 					"malloc failed. **\n");
1647 				return -1;
1648 			}
1649 			ext4fs_indir1_size = blksz;
1650 			ext4fs_indir1_blkno = -1;
1651 		}
1652 		if (blksz != ext4fs_indir1_size) {
1653 			free(ext4fs_indir1_block);
1654 			ext4fs_indir1_block = NULL;
1655 			ext4fs_indir1_size = 0;
1656 			ext4fs_indir1_blkno = -1;
1657 			ext4fs_indir1_block = zalloc(blksz);
1658 			if (ext4fs_indir1_block == NULL) {
1659 				printf("** SI ext2fs read block (indir 1):"
1660 					"malloc failed. **\n");
1661 				return -1;
1662 			}
1663 			ext4fs_indir1_size = blksz;
1664 		}
1665 		if ((le32_to_cpu(inode->b.blocks.indir_block) <<
1666 		     log2_blksz) != ext4fs_indir1_blkno) {
1667 			status =
1668 			    ext4fs_devread((lbaint_t)le32_to_cpu
1669 					   (inode->b.blocks.
1670 					    indir_block) << log2_blksz, 0,
1671 					   blksz, (char *)ext4fs_indir1_block);
1672 			if (status == 0) {
1673 				printf("** SI ext2fs read block (indir 1)"
1674 					"failed. **\n");
1675 				return -1;
1676 			}
1677 			ext4fs_indir1_blkno =
1678 				le32_to_cpu(inode->b.blocks.
1679 					       indir_block) << log2_blksz;
1680 		}
1681 		blknr = le32_to_cpu(ext4fs_indir1_block
1682 				      [fileblock - INDIRECT_BLOCKS]);
1683 	}
1684 	/* Double indirect. */
1685 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
1686 					(blksz / 4 + 1)))) {
1687 
1688 		long int perblock = blksz / 4;
1689 		long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
1690 
1691 		if (ext4fs_indir1_block == NULL) {
1692 			ext4fs_indir1_block = zalloc(blksz);
1693 			if (ext4fs_indir1_block == NULL) {
1694 				printf("** DI ext2fs read block (indir 2 1)"
1695 					"malloc failed. **\n");
1696 				return -1;
1697 			}
1698 			ext4fs_indir1_size = blksz;
1699 			ext4fs_indir1_blkno = -1;
1700 		}
1701 		if (blksz != ext4fs_indir1_size) {
1702 			free(ext4fs_indir1_block);
1703 			ext4fs_indir1_block = NULL;
1704 			ext4fs_indir1_size = 0;
1705 			ext4fs_indir1_blkno = -1;
1706 			ext4fs_indir1_block = zalloc(blksz);
1707 			if (ext4fs_indir1_block == NULL) {
1708 				printf("** DI ext2fs read block (indir 2 1)"
1709 					"malloc failed. **\n");
1710 				return -1;
1711 			}
1712 			ext4fs_indir1_size = blksz;
1713 		}
1714 		if ((le32_to_cpu(inode->b.blocks.double_indir_block) <<
1715 		     log2_blksz) != ext4fs_indir1_blkno) {
1716 			status =
1717 			    ext4fs_devread((lbaint_t)le32_to_cpu
1718 					   (inode->b.blocks.
1719 					    double_indir_block) << log2_blksz,
1720 					   0, blksz,
1721 					   (char *)ext4fs_indir1_block);
1722 			if (status == 0) {
1723 				printf("** DI ext2fs read block (indir 2 1)"
1724 					"failed. **\n");
1725 				return -1;
1726 			}
1727 			ext4fs_indir1_blkno =
1728 			    le32_to_cpu(inode->b.blocks.double_indir_block) <<
1729 			    log2_blksz;
1730 		}
1731 
1732 		if (ext4fs_indir2_block == NULL) {
1733 			ext4fs_indir2_block = zalloc(blksz);
1734 			if (ext4fs_indir2_block == NULL) {
1735 				printf("** DI ext2fs read block (indir 2 2)"
1736 					"malloc failed. **\n");
1737 				return -1;
1738 			}
1739 			ext4fs_indir2_size = blksz;
1740 			ext4fs_indir2_blkno = -1;
1741 		}
1742 		if (blksz != ext4fs_indir2_size) {
1743 			free(ext4fs_indir2_block);
1744 			ext4fs_indir2_block = NULL;
1745 			ext4fs_indir2_size = 0;
1746 			ext4fs_indir2_blkno = -1;
1747 			ext4fs_indir2_block = zalloc(blksz);
1748 			if (ext4fs_indir2_block == NULL) {
1749 				printf("** DI ext2fs read block (indir 2 2)"
1750 					"malloc failed. **\n");
1751 				return -1;
1752 			}
1753 			ext4fs_indir2_size = blksz;
1754 		}
1755 		if ((le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
1756 		     log2_blksz) != ext4fs_indir2_blkno) {
1757 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1758 						(ext4fs_indir1_block
1759 						 [rblock /
1760 						  perblock]) << log2_blksz, 0,
1761 						blksz,
1762 						(char *)ext4fs_indir2_block);
1763 			if (status == 0) {
1764 				printf("** DI ext2fs read block (indir 2 2)"
1765 					"failed. **\n");
1766 				return -1;
1767 			}
1768 			ext4fs_indir2_blkno =
1769 			    le32_to_cpu(ext4fs_indir1_block[rblock
1770 							      /
1771 							      perblock]) <<
1772 			    log2_blksz;
1773 		}
1774 		blknr = le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
1775 	}
1776 	/* Tripple indirect. */
1777 	else {
1778 		rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
1779 				      (blksz / 4 * blksz / 4));
1780 		perblock_child = blksz / 4;
1781 		perblock_parent = ((blksz / 4) * (blksz / 4));
1782 
1783 		if (ext4fs_indir1_block == NULL) {
1784 			ext4fs_indir1_block = zalloc(blksz);
1785 			if (ext4fs_indir1_block == NULL) {
1786 				printf("** TI ext2fs read block (indir 2 1)"
1787 					"malloc failed. **\n");
1788 				return -1;
1789 			}
1790 			ext4fs_indir1_size = blksz;
1791 			ext4fs_indir1_blkno = -1;
1792 		}
1793 		if (blksz != ext4fs_indir1_size) {
1794 			free(ext4fs_indir1_block);
1795 			ext4fs_indir1_block = NULL;
1796 			ext4fs_indir1_size = 0;
1797 			ext4fs_indir1_blkno = -1;
1798 			ext4fs_indir1_block = zalloc(blksz);
1799 			if (ext4fs_indir1_block == NULL) {
1800 				printf("** TI ext2fs read block (indir 2 1)"
1801 					"malloc failed. **\n");
1802 				return -1;
1803 			}
1804 			ext4fs_indir1_size = blksz;
1805 		}
1806 		if ((le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1807 		     log2_blksz) != ext4fs_indir1_blkno) {
1808 			status = ext4fs_devread
1809 			    ((lbaint_t)
1810 			     le32_to_cpu(inode->b.blocks.triple_indir_block)
1811 			     << log2_blksz, 0, blksz,
1812 			     (char *)ext4fs_indir1_block);
1813 			if (status == 0) {
1814 				printf("** TI ext2fs read block (indir 2 1)"
1815 					"failed. **\n");
1816 				return -1;
1817 			}
1818 			ext4fs_indir1_blkno =
1819 			    le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1820 			    log2_blksz;
1821 		}
1822 
1823 		if (ext4fs_indir2_block == NULL) {
1824 			ext4fs_indir2_block = zalloc(blksz);
1825 			if (ext4fs_indir2_block == NULL) {
1826 				printf("** TI ext2fs read block (indir 2 2)"
1827 					"malloc failed. **\n");
1828 				return -1;
1829 			}
1830 			ext4fs_indir2_size = blksz;
1831 			ext4fs_indir2_blkno = -1;
1832 		}
1833 		if (blksz != ext4fs_indir2_size) {
1834 			free(ext4fs_indir2_block);
1835 			ext4fs_indir2_block = NULL;
1836 			ext4fs_indir2_size = 0;
1837 			ext4fs_indir2_blkno = -1;
1838 			ext4fs_indir2_block = zalloc(blksz);
1839 			if (ext4fs_indir2_block == NULL) {
1840 				printf("** TI ext2fs read block (indir 2 2)"
1841 					"malloc failed. **\n");
1842 				return -1;
1843 			}
1844 			ext4fs_indir2_size = blksz;
1845 		}
1846 		if ((le32_to_cpu(ext4fs_indir1_block[rblock /
1847 						       perblock_parent]) <<
1848 		     log2_blksz)
1849 		    != ext4fs_indir2_blkno) {
1850 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1851 						(ext4fs_indir1_block
1852 						 [rblock /
1853 						  perblock_parent]) <<
1854 						log2_blksz, 0, blksz,
1855 						(char *)ext4fs_indir2_block);
1856 			if (status == 0) {
1857 				printf("** TI ext2fs read block (indir 2 2)"
1858 					"failed. **\n");
1859 				return -1;
1860 			}
1861 			ext4fs_indir2_blkno =
1862 			    le32_to_cpu(ext4fs_indir1_block[rblock /
1863 							      perblock_parent])
1864 			    << log2_blksz;
1865 		}
1866 
1867 		if (ext4fs_indir3_block == NULL) {
1868 			ext4fs_indir3_block = zalloc(blksz);
1869 			if (ext4fs_indir3_block == NULL) {
1870 				printf("** TI ext2fs read block (indir 2 2)"
1871 					"malloc failed. **\n");
1872 				return -1;
1873 			}
1874 			ext4fs_indir3_size = blksz;
1875 			ext4fs_indir3_blkno = -1;
1876 		}
1877 		if (blksz != ext4fs_indir3_size) {
1878 			free(ext4fs_indir3_block);
1879 			ext4fs_indir3_block = NULL;
1880 			ext4fs_indir3_size = 0;
1881 			ext4fs_indir3_blkno = -1;
1882 			ext4fs_indir3_block = zalloc(blksz);
1883 			if (ext4fs_indir3_block == NULL) {
1884 				printf("** TI ext2fs read block (indir 2 2)"
1885 					"malloc failed. **\n");
1886 				return -1;
1887 			}
1888 			ext4fs_indir3_size = blksz;
1889 		}
1890 		if ((le32_to_cpu(ext4fs_indir2_block[rblock
1891 						       /
1892 						       perblock_child]) <<
1893 		     log2_blksz) != ext4fs_indir3_blkno) {
1894 			status =
1895 			    ext4fs_devread((lbaint_t)le32_to_cpu
1896 					   (ext4fs_indir2_block
1897 					    [(rblock / perblock_child)
1898 					     % (blksz / 4)]) << log2_blksz, 0,
1899 					   blksz, (char *)ext4fs_indir3_block);
1900 			if (status == 0) {
1901 				printf("** TI ext2fs read block (indir 2 2)"
1902 				       "failed. **\n");
1903 				return -1;
1904 			}
1905 			ext4fs_indir3_blkno =
1906 			    le32_to_cpu(ext4fs_indir2_block[(rblock /
1907 							       perblock_child) %
1908 							      (blksz /
1909 							       4)]) <<
1910 			    log2_blksz;
1911 		}
1912 
1913 		blknr = le32_to_cpu(ext4fs_indir3_block
1914 				      [rblock % perblock_child]);
1915 	}
1916 	debug("read_allocated_block %ld\n", blknr);
1917 
1918 	return blknr;
1919 }
1920 
1921 /**
1922  * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's
1923  *			    global pointers
1924  *
1925  * This function assures that for a file with the same name but different size
1926  * the sequential store on the ext4 filesystem will be correct.
1927  *
1928  * In this function the global data, responsible for internal representation
1929  * of the ext4 data are initialized to the reset state. Without this, during
1930  * replacement of the smaller file with the bigger truncation of new file was
1931  * performed.
1932  */
1933 void ext4fs_reinit_global(void)
1934 {
1935 	if (ext4fs_indir1_block != NULL) {
1936 		free(ext4fs_indir1_block);
1937 		ext4fs_indir1_block = NULL;
1938 		ext4fs_indir1_size = 0;
1939 		ext4fs_indir1_blkno = -1;
1940 	}
1941 	if (ext4fs_indir2_block != NULL) {
1942 		free(ext4fs_indir2_block);
1943 		ext4fs_indir2_block = NULL;
1944 		ext4fs_indir2_size = 0;
1945 		ext4fs_indir2_blkno = -1;
1946 	}
1947 	if (ext4fs_indir3_block != NULL) {
1948 		free(ext4fs_indir3_block);
1949 		ext4fs_indir3_block = NULL;
1950 		ext4fs_indir3_size = 0;
1951 		ext4fs_indir3_blkno = -1;
1952 	}
1953 }
1954 void ext4fs_close(void)
1955 {
1956 	if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
1957 		ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
1958 		ext4fs_file = NULL;
1959 	}
1960 	if (ext4fs_root != NULL) {
1961 		free(ext4fs_root);
1962 		ext4fs_root = NULL;
1963 	}
1964 
1965 	ext4fs_reinit_global();
1966 }
1967 
1968 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
1969 				struct ext2fs_node **fnode, int *ftype)
1970 {
1971 	unsigned int fpos = 0;
1972 	int status;
1973 	loff_t actread;
1974 	struct ext2fs_node *diro = (struct ext2fs_node *) dir;
1975 
1976 #ifdef DEBUG
1977 	if (name != NULL)
1978 		printf("Iterate dir %s\n", name);
1979 #endif /* of DEBUG */
1980 	if (!diro->inode_read) {
1981 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
1982 		if (status == 0)
1983 			return 0;
1984 	}
1985 	/* Search the file.  */
1986 	while (fpos < le32_to_cpu(diro->inode.size)) {
1987 		struct ext2_dirent dirent;
1988 
1989 		status = ext4fs_read_file(diro, fpos,
1990 					   sizeof(struct ext2_dirent),
1991 					   (char *)&dirent, &actread);
1992 		if (status < 0)
1993 			return 0;
1994 
1995 		if (dirent.direntlen == 0) {
1996 			printf("Failed to iterate over directory %s\n", name);
1997 			return 0;
1998 		}
1999 
2000 		if (dirent.namelen != 0) {
2001 			char filename[dirent.namelen + 1];
2002 			struct ext2fs_node *fdiro;
2003 			int type = FILETYPE_UNKNOWN;
2004 
2005 			status = ext4fs_read_file(diro,
2006 						  fpos +
2007 						  sizeof(struct ext2_dirent),
2008 						  dirent.namelen, filename,
2009 						  &actread);
2010 			if (status < 0)
2011 				return 0;
2012 
2013 			fdiro = zalloc(sizeof(struct ext2fs_node));
2014 			if (!fdiro)
2015 				return 0;
2016 
2017 			fdiro->data = diro->data;
2018 			fdiro->ino = le32_to_cpu(dirent.inode);
2019 
2020 			filename[dirent.namelen] = '\0';
2021 
2022 			if (dirent.filetype != FILETYPE_UNKNOWN) {
2023 				fdiro->inode_read = 0;
2024 
2025 				if (dirent.filetype == FILETYPE_DIRECTORY)
2026 					type = FILETYPE_DIRECTORY;
2027 				else if (dirent.filetype == FILETYPE_SYMLINK)
2028 					type = FILETYPE_SYMLINK;
2029 				else if (dirent.filetype == FILETYPE_REG)
2030 					type = FILETYPE_REG;
2031 			} else {
2032 				status = ext4fs_read_inode(diro->data,
2033 							   le32_to_cpu
2034 							   (dirent.inode),
2035 							   &fdiro->inode);
2036 				if (status == 0) {
2037 					free(fdiro);
2038 					return 0;
2039 				}
2040 				fdiro->inode_read = 1;
2041 
2042 				if ((le16_to_cpu(fdiro->inode.mode) &
2043 				     FILETYPE_INO_MASK) ==
2044 				    FILETYPE_INO_DIRECTORY) {
2045 					type = FILETYPE_DIRECTORY;
2046 				} else if ((le16_to_cpu(fdiro->inode.mode)
2047 					    & FILETYPE_INO_MASK) ==
2048 					   FILETYPE_INO_SYMLINK) {
2049 					type = FILETYPE_SYMLINK;
2050 				} else if ((le16_to_cpu(fdiro->inode.mode)
2051 					    & FILETYPE_INO_MASK) ==
2052 					   FILETYPE_INO_REG) {
2053 					type = FILETYPE_REG;
2054 				}
2055 			}
2056 #ifdef DEBUG
2057 			printf("iterate >%s<\n", filename);
2058 #endif /* of DEBUG */
2059 			if ((name != NULL) && (fnode != NULL)
2060 			    && (ftype != NULL)) {
2061 				if (strcmp(filename, name) == 0) {
2062 					*ftype = type;
2063 					*fnode = fdiro;
2064 					return 1;
2065 				}
2066 			} else {
2067 				if (fdiro->inode_read == 0) {
2068 					status = ext4fs_read_inode(diro->data,
2069 								 le32_to_cpu(
2070 								 dirent.inode),
2071 								 &fdiro->inode);
2072 					if (status == 0) {
2073 						free(fdiro);
2074 						return 0;
2075 					}
2076 					fdiro->inode_read = 1;
2077 				}
2078 				switch (type) {
2079 				case FILETYPE_DIRECTORY:
2080 					printf("<DIR> ");
2081 					break;
2082 				case FILETYPE_SYMLINK:
2083 					printf("<SYM> ");
2084 					break;
2085 				case FILETYPE_REG:
2086 					printf("      ");
2087 					break;
2088 				default:
2089 					printf("< ? > ");
2090 					break;
2091 				}
2092 				printf("%10u %s\n",
2093 				       le32_to_cpu(fdiro->inode.size),
2094 					filename);
2095 			}
2096 			free(fdiro);
2097 		}
2098 		fpos += le16_to_cpu(dirent.direntlen);
2099 	}
2100 	return 0;
2101 }
2102 
2103 static char *ext4fs_read_symlink(struct ext2fs_node *node)
2104 {
2105 	char *symlink;
2106 	struct ext2fs_node *diro = node;
2107 	int status;
2108 	loff_t actread;
2109 
2110 	if (!diro->inode_read) {
2111 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2112 		if (status == 0)
2113 			return NULL;
2114 	}
2115 	symlink = zalloc(le32_to_cpu(diro->inode.size) + 1);
2116 	if (!symlink)
2117 		return NULL;
2118 
2119 	if (le32_to_cpu(diro->inode.size) < sizeof(diro->inode.b.symlink)) {
2120 		strncpy(symlink, diro->inode.b.symlink,
2121 			 le32_to_cpu(diro->inode.size));
2122 	} else {
2123 		status = ext4fs_read_file(diro, 0,
2124 					   le32_to_cpu(diro->inode.size),
2125 					   symlink, &actread);
2126 		if ((status < 0) || (actread == 0)) {
2127 			free(symlink);
2128 			return NULL;
2129 		}
2130 	}
2131 	symlink[le32_to_cpu(diro->inode.size)] = '\0';
2132 	return symlink;
2133 }
2134 
2135 static int ext4fs_find_file1(const char *currpath,
2136 			     struct ext2fs_node *currroot,
2137 			     struct ext2fs_node **currfound, int *foundtype)
2138 {
2139 	char fpath[strlen(currpath) + 1];
2140 	char *name = fpath;
2141 	char *next;
2142 	int status;
2143 	int type = FILETYPE_DIRECTORY;
2144 	struct ext2fs_node *currnode = currroot;
2145 	struct ext2fs_node *oldnode = currroot;
2146 
2147 	strncpy(fpath, currpath, strlen(currpath) + 1);
2148 
2149 	/* Remove all leading slashes. */
2150 	while (*name == '/')
2151 		name++;
2152 
2153 	if (!*name) {
2154 		*currfound = currnode;
2155 		return 1;
2156 	}
2157 
2158 	for (;;) {
2159 		int found;
2160 
2161 		/* Extract the actual part from the pathname. */
2162 		next = strchr(name, '/');
2163 		if (next) {
2164 			/* Remove all leading slashes. */
2165 			while (*next == '/')
2166 				*(next++) = '\0';
2167 		}
2168 
2169 		if (type != FILETYPE_DIRECTORY) {
2170 			ext4fs_free_node(currnode, currroot);
2171 			return 0;
2172 		}
2173 
2174 		oldnode = currnode;
2175 
2176 		/* Iterate over the directory. */
2177 		found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
2178 		if (found == 0)
2179 			return 0;
2180 
2181 		if (found == -1)
2182 			break;
2183 
2184 		/* Read in the symlink and follow it. */
2185 		if (type == FILETYPE_SYMLINK) {
2186 			char *symlink;
2187 
2188 			/* Test if the symlink does not loop. */
2189 			if (++symlinknest == 8) {
2190 				ext4fs_free_node(currnode, currroot);
2191 				ext4fs_free_node(oldnode, currroot);
2192 				return 0;
2193 			}
2194 
2195 			symlink = ext4fs_read_symlink(currnode);
2196 			ext4fs_free_node(currnode, currroot);
2197 
2198 			if (!symlink) {
2199 				ext4fs_free_node(oldnode, currroot);
2200 				return 0;
2201 			}
2202 
2203 			debug("Got symlink >%s<\n", symlink);
2204 
2205 			if (symlink[0] == '/') {
2206 				ext4fs_free_node(oldnode, currroot);
2207 				oldnode = &ext4fs_root->diropen;
2208 			}
2209 
2210 			/* Lookup the node the symlink points to. */
2211 			status = ext4fs_find_file1(symlink, oldnode,
2212 						    &currnode, &type);
2213 
2214 			free(symlink);
2215 
2216 			if (status == 0) {
2217 				ext4fs_free_node(oldnode, currroot);
2218 				return 0;
2219 			}
2220 		}
2221 
2222 		ext4fs_free_node(oldnode, currroot);
2223 
2224 		/* Found the node! */
2225 		if (!next || *next == '\0') {
2226 			*currfound = currnode;
2227 			*foundtype = type;
2228 			return 1;
2229 		}
2230 		name = next;
2231 	}
2232 	return -1;
2233 }
2234 
2235 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
2236 	struct ext2fs_node **foundnode, int expecttype)
2237 {
2238 	int status;
2239 	int foundtype = FILETYPE_DIRECTORY;
2240 
2241 	symlinknest = 0;
2242 	if (!path)
2243 		return 0;
2244 
2245 	status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
2246 	if (status == 0)
2247 		return 0;
2248 
2249 	/* Check if the node that was found was of the expected type. */
2250 	if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
2251 		return 0;
2252 	else if ((expecttype == FILETYPE_DIRECTORY)
2253 		   && (foundtype != expecttype))
2254 		return 0;
2255 
2256 	return 1;
2257 }
2258 
2259 int ext4fs_open(const char *filename, loff_t *len)
2260 {
2261 	struct ext2fs_node *fdiro = NULL;
2262 	int status;
2263 
2264 	if (ext4fs_root == NULL)
2265 		return -1;
2266 
2267 	ext4fs_file = NULL;
2268 	status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
2269 				  FILETYPE_REG);
2270 	if (status == 0)
2271 		goto fail;
2272 
2273 	if (!fdiro->inode_read) {
2274 		status = ext4fs_read_inode(fdiro->data, fdiro->ino,
2275 				&fdiro->inode);
2276 		if (status == 0)
2277 			goto fail;
2278 	}
2279 	*len = le32_to_cpu(fdiro->inode.size);
2280 	ext4fs_file = fdiro;
2281 
2282 	return 0;
2283 fail:
2284 	ext4fs_free_node(fdiro, &ext4fs_root->diropen);
2285 
2286 	return -1;
2287 }
2288 
2289 int ext4fs_mount(unsigned part_length)
2290 {
2291 	struct ext2_data *data;
2292 	int status;
2293 	struct ext_filesystem *fs = get_fs();
2294 	data = zalloc(SUPERBLOCK_SIZE);
2295 	if (!data)
2296 		return 0;
2297 
2298 	/* Read the superblock. */
2299 	status = ext4_read_superblock((char *)&data->sblock);
2300 
2301 	if (status == 0)
2302 		goto fail;
2303 
2304 	/* Make sure this is an ext2 filesystem. */
2305 	if (le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
2306 		goto fail;
2307 
2308 	/*
2309 	 * The 64bit feature was enabled when metadata_csum was enabled
2310 	 * and we do not support metadata_csum (and cannot reliably find
2311 	 * files when it is set.  Refuse to mount.
2312 	 */
2313 	if (le32_to_cpu(data->sblock.feature_incompat) & EXT4_FEATURE_INCOMPAT_64BIT) {
2314 		printf("Unsupported feature found (64bit, possibly metadata_csum), not mounting\n");
2315 		goto fail;
2316 	}
2317 
2318 	if (le32_to_cpu(data->sblock.revision_level) == 0) {
2319 		fs->inodesz = 128;
2320 	} else {
2321 		debug("EXT4 features COMPAT: %08x INCOMPAT: %08x RO_COMPAT: %08x\n",
2322 		      __le32_to_cpu(data->sblock.feature_compatibility),
2323 		      __le32_to_cpu(data->sblock.feature_incompat),
2324 		      __le32_to_cpu(data->sblock.feature_ro_compat));
2325 
2326 		fs->inodesz = le16_to_cpu(data->sblock.inode_size);
2327 		fs->gdsize = le32_to_cpu(data->sblock.feature_incompat) &
2328 			EXT4_FEATURE_INCOMPAT_64BIT ?
2329 			le16_to_cpu(data->sblock.descriptor_size) : 32;
2330 	}
2331 
2332 	debug("EXT2 rev %d, inode_size %d, descriptor size %d\n",
2333 	      le32_to_cpu(data->sblock.revision_level),
2334 	      fs->inodesz, fs->gdsize);
2335 
2336 	data->diropen.data = data;
2337 	data->diropen.ino = 2;
2338 	data->diropen.inode_read = 1;
2339 	data->inode = &data->diropen.inode;
2340 
2341 	status = ext4fs_read_inode(data, 2, data->inode);
2342 	if (status == 0)
2343 		goto fail;
2344 
2345 	ext4fs_root = data;
2346 
2347 	return 1;
2348 fail:
2349 	printf("Failed to mount ext2 filesystem...\n");
2350 	free(data);
2351 	ext4fs_root = NULL;
2352 
2353 	return 0;
2354 }
2355