xref: /openbmc/u-boot/fs/ext4/ext4_common.c (revision 83ee44ab)
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 	uint64_t free_blocks = le32_to_cpu(sb->free_blocks);
64 	free_blocks += (uint64_t)le32_to_cpu(sb->free_blocks_high) << 32;
65 	free_blocks--;
66 
67 	sb->free_blocks = cpu_to_le32(free_blocks & 0xffffffff);
68 	sb->free_blocks_high = cpu_to_le16(free_blocks >> 32);
69 }
70 
71 static inline void ext4fs_bg_free_inodes_dec
72 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
73 {
74 	uint32_t free_inodes = le16_to_cpu(bg->free_inodes);
75 	if (fs->gdsize == 64)
76 		free_inodes += le16_to_cpu(bg->free_inodes_high) << 16;
77 	free_inodes--;
78 
79 	bg->free_inodes = cpu_to_le16(free_inodes & 0xffff);
80 	if (fs->gdsize == 64)
81 		bg->free_inodes_high = cpu_to_le16(free_inodes >> 16);
82 }
83 
84 static inline void ext4fs_bg_free_blocks_dec
85 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
86 {
87 	uint32_t free_blocks = le16_to_cpu(bg->free_blocks);
88 	if (fs->gdsize == 64)
89 		free_blocks += le16_to_cpu(bg->free_blocks_high) << 16;
90 	free_blocks--;
91 
92 	bg->free_blocks = cpu_to_le16(free_blocks & 0xffff);
93 	if (fs->gdsize == 64)
94 		bg->free_blocks_high = cpu_to_le16(free_blocks >> 16);
95 }
96 
97 static inline void ext4fs_bg_itable_unused_dec
98 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
99 {
100 	uint32_t free_inodes = le16_to_cpu(bg->bg_itable_unused);
101 	if (fs->gdsize == 64)
102 		free_inodes += le16_to_cpu(bg->bg_itable_unused_high) << 16;
103 	free_inodes--;
104 
105 	bg->bg_itable_unused = cpu_to_le16(free_inodes & 0xffff);
106 	if (fs->gdsize == 64)
107 		bg->bg_itable_unused_high = cpu_to_le16(free_inodes >> 16);
108 }
109 
110 uint64_t ext4fs_sb_get_free_blocks(const struct ext2_sblock *sb)
111 {
112 	uint64_t free_blocks = le32_to_cpu(sb->free_blocks);
113 	free_blocks += (uint64_t)le32_to_cpu(sb->free_blocks_high) << 32;
114 	return free_blocks;
115 }
116 
117 void ext4fs_sb_set_free_blocks(struct ext2_sblock *sb, uint64_t free_blocks)
118 {
119 	sb->free_blocks = cpu_to_le32(free_blocks & 0xffffffff);
120 	sb->free_blocks_high = cpu_to_le16(free_blocks >> 32);
121 }
122 
123 uint32_t ext4fs_bg_get_free_blocks(const struct ext2_block_group *bg,
124 				   const struct ext_filesystem *fs)
125 {
126 	uint32_t free_blocks = le16_to_cpu(bg->free_blocks);
127 	if (fs->gdsize == 64)
128 		free_blocks += le16_to_cpu(bg->free_blocks_high) << 16;
129 	return free_blocks;
130 }
131 
132 static inline
133 uint32_t ext4fs_bg_get_free_inodes(const struct ext2_block_group *bg,
134 				   const struct ext_filesystem *fs)
135 {
136 	uint32_t free_inodes = le16_to_cpu(bg->free_inodes);
137 	if (fs->gdsize == 64)
138 		free_inodes += le16_to_cpu(bg->free_inodes_high) << 16;
139 	return free_inodes;
140 }
141 
142 static inline uint16_t ext4fs_bg_get_flags(const struct ext2_block_group *bg)
143 {
144 	return le16_to_cpu(bg->bg_flags);
145 }
146 
147 static inline void ext4fs_bg_set_flags(struct ext2_block_group *bg,
148 				       uint16_t flags)
149 {
150 	bg->bg_flags = cpu_to_le16(flags);
151 }
152 
153 /* Block number of the block bitmap */
154 uint64_t ext4fs_bg_get_block_id(const struct ext2_block_group *bg,
155 				const struct ext_filesystem *fs)
156 {
157 	uint64_t block_nr = le32_to_cpu(bg->block_id);
158 	if (fs->gdsize == 64)
159 		block_nr += (uint64_t)le32_to_cpu(bg->block_id_high) << 32;
160 	return block_nr;
161 }
162 
163 /* Block number of the inode bitmap */
164 uint64_t ext4fs_bg_get_inode_id(const struct ext2_block_group *bg,
165 				const struct ext_filesystem *fs)
166 {
167 	uint64_t block_nr = le32_to_cpu(bg->inode_id);
168 	if (fs->gdsize == 64)
169 		block_nr += (uint64_t)le32_to_cpu(bg->inode_id_high) << 32;
170 	return block_nr;
171 }
172 #endif
173 
174 /* Block number of the inode table */
175 uint64_t ext4fs_bg_get_inode_table_id(const struct ext2_block_group *bg,
176 				      const struct ext_filesystem *fs)
177 {
178 	uint64_t block_nr = le32_to_cpu(bg->inode_table_id);
179 	if (fs->gdsize == 64)
180 		block_nr +=
181 			(uint64_t)le32_to_cpu(bg->inode_table_id_high) << 32;
182 	return block_nr;
183 }
184 
185 #if defined(CONFIG_EXT4_WRITE)
186 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n)
187 {
188 	uint32_t res = size / n;
189 	if (res * n != size)
190 		res++;
191 
192 	return res;
193 }
194 
195 void put_ext4(uint64_t off, void *buf, uint32_t size)
196 {
197 	uint64_t startblock;
198 	uint64_t remainder;
199 	unsigned char *temp_ptr = NULL;
200 	struct ext_filesystem *fs = get_fs();
201 	int log2blksz = fs->dev_desc->log2blksz;
202 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, sec_buf, fs->dev_desc->blksz);
203 
204 	startblock = off >> log2blksz;
205 	startblock += part_offset;
206 	remainder = off & (uint64_t)(fs->dev_desc->blksz - 1);
207 
208 	if (fs->dev_desc == NULL)
209 		return;
210 
211 	if ((startblock + (size >> log2blksz)) >
212 	    (part_offset + fs->total_sect)) {
213 		printf("part_offset is " LBAFU "\n", part_offset);
214 		printf("total_sector is %" PRIu64 "\n", fs->total_sect);
215 		printf("error: overflow occurs\n");
216 		return;
217 	}
218 
219 	if (remainder) {
220 		blk_dread(fs->dev_desc, startblock, 1, sec_buf);
221 		temp_ptr = sec_buf;
222 		memcpy((temp_ptr + remainder), (unsigned char *)buf, size);
223 		blk_dwrite(fs->dev_desc, startblock, 1, sec_buf);
224 	} else {
225 		if (size >> log2blksz != 0) {
226 			blk_dwrite(fs->dev_desc, startblock, size >> log2blksz,
227 				   (unsigned long *)buf);
228 		} else {
229 			blk_dread(fs->dev_desc, startblock, 1, sec_buf);
230 			temp_ptr = sec_buf;
231 			memcpy(temp_ptr, buf, size);
232 			blk_dwrite(fs->dev_desc, startblock, 1,
233 				   (unsigned long *)sec_buf);
234 		}
235 	}
236 }
237 
238 static int _get_new_inode_no(unsigned char *buffer)
239 {
240 	struct ext_filesystem *fs = get_fs();
241 	unsigned char input;
242 	int operand, status;
243 	int count = 1;
244 	int j = 0;
245 
246 	/* get the blocksize of the filesystem */
247 	unsigned char *ptr = buffer;
248 	while (*ptr == 255) {
249 		ptr++;
250 		count += 8;
251 		if (count > le32_to_cpu(ext4fs_root->sblock.inodes_per_group))
252 			return -1;
253 	}
254 
255 	for (j = 0; j < fs->blksz; j++) {
256 		input = *ptr;
257 		int i = 0;
258 		while (i <= 7) {
259 			operand = 1 << i;
260 			status = input & operand;
261 			if (status) {
262 				i++;
263 				count++;
264 			} else {
265 				*ptr |= operand;
266 				return count;
267 			}
268 		}
269 		ptr = ptr + 1;
270 	}
271 
272 	return -1;
273 }
274 
275 static int _get_new_blk_no(unsigned char *buffer)
276 {
277 	int operand;
278 	int count = 0;
279 	int i;
280 	unsigned char *ptr = buffer;
281 	struct ext_filesystem *fs = get_fs();
282 
283 	while (*ptr == 255) {
284 		ptr++;
285 		count += 8;
286 		if (count == (fs->blksz * 8))
287 			return -1;
288 	}
289 
290 	if (fs->blksz == 1024)
291 		count += 1;
292 
293 	for (i = 0; i <= 7; i++) {
294 		operand = 1 << i;
295 		if (*ptr & operand) {
296 			count++;
297 		} else {
298 			*ptr |= operand;
299 			return count;
300 		}
301 	}
302 
303 	return -1;
304 }
305 
306 int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index)
307 {
308 	int i, remainder, status;
309 	unsigned char *ptr = buffer;
310 	unsigned char operand;
311 	i = blockno / 8;
312 	remainder = blockno % 8;
313 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
314 
315 	i = i - (index * blocksize);
316 	if (blocksize != 1024) {
317 		ptr = ptr + i;
318 		operand = 1 << remainder;
319 		status = *ptr & operand;
320 		if (status)
321 			return -1;
322 
323 		*ptr = *ptr | operand;
324 		return 0;
325 	} else {
326 		if (remainder == 0) {
327 			ptr = ptr + i - 1;
328 			operand = (1 << 7);
329 		} else {
330 			ptr = ptr + i;
331 			operand = (1 << (remainder - 1));
332 		}
333 		status = *ptr & operand;
334 		if (status)
335 			return -1;
336 
337 		*ptr = *ptr | operand;
338 		return 0;
339 	}
340 }
341 
342 void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index)
343 {
344 	int i, remainder, status;
345 	unsigned char *ptr = buffer;
346 	unsigned char operand;
347 	i = blockno / 8;
348 	remainder = blockno % 8;
349 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
350 
351 	i = i - (index * blocksize);
352 	if (blocksize != 1024) {
353 		ptr = ptr + i;
354 		operand = (1 << remainder);
355 		status = *ptr & operand;
356 		if (status)
357 			*ptr = *ptr & ~(operand);
358 	} else {
359 		if (remainder == 0) {
360 			ptr = ptr + i - 1;
361 			operand = (1 << 7);
362 		} else {
363 			ptr = ptr + i;
364 			operand = (1 << (remainder - 1));
365 		}
366 		status = *ptr & operand;
367 		if (status)
368 			*ptr = *ptr & ~(operand);
369 	}
370 }
371 
372 int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index)
373 {
374 	int i, remainder, status;
375 	unsigned char *ptr = buffer;
376 	unsigned char operand;
377 
378 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
379 	i = inode_no / 8;
380 	remainder = inode_no % 8;
381 	if (remainder == 0) {
382 		ptr = ptr + i - 1;
383 		operand = (1 << 7);
384 	} else {
385 		ptr = ptr + i;
386 		operand = (1 << (remainder - 1));
387 	}
388 	status = *ptr & operand;
389 	if (status)
390 		return -1;
391 
392 	*ptr = *ptr | operand;
393 
394 	return 0;
395 }
396 
397 void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index)
398 {
399 	int i, remainder, status;
400 	unsigned char *ptr = buffer;
401 	unsigned char operand;
402 
403 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
404 	i = inode_no / 8;
405 	remainder = inode_no % 8;
406 	if (remainder == 0) {
407 		ptr = ptr + i - 1;
408 		operand = (1 << 7);
409 	} else {
410 		ptr = ptr + i;
411 		operand = (1 << (remainder - 1));
412 	}
413 	status = *ptr & operand;
414 	if (status)
415 		*ptr = *ptr & ~(operand);
416 }
417 
418 uint16_t ext4fs_checksum_update(uint32_t i)
419 {
420 	struct ext2_block_group *desc;
421 	struct ext_filesystem *fs = get_fs();
422 	uint16_t crc = 0;
423 	__le32 le32_i = cpu_to_le32(i);
424 
425 	desc = ext4fs_get_group_descriptor(fs, i);
426 	if (le32_to_cpu(fs->sb->feature_ro_compat) & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
427 		int offset = offsetof(struct ext2_block_group, bg_checksum);
428 
429 		crc = ext2fs_crc16(~0, fs->sb->unique_id,
430 				   sizeof(fs->sb->unique_id));
431 		crc = ext2fs_crc16(crc, &le32_i, sizeof(le32_i));
432 		crc = ext2fs_crc16(crc, desc, offset);
433 		offset += sizeof(desc->bg_checksum);	/* skip checksum */
434 		assert(offset == sizeof(*desc));
435 		if (offset < fs->gdsize) {
436 			crc = ext2fs_crc16(crc, (__u8 *)desc + offset,
437 					   fs->gdsize - offset);
438 		}
439 	}
440 
441 	return crc;
442 }
443 
444 static int check_void_in_dentry(struct ext2_dirent *dir, char *filename)
445 {
446 	int dentry_length;
447 	int sizeof_void_space;
448 	int new_entry_byte_reqd;
449 	short padding_factor = 0;
450 
451 	if (dir->namelen % 4 != 0)
452 		padding_factor = 4 - (dir->namelen % 4);
453 
454 	dentry_length = sizeof(struct ext2_dirent) +
455 			dir->namelen + padding_factor;
456 	sizeof_void_space = le16_to_cpu(dir->direntlen) - dentry_length;
457 	if (sizeof_void_space == 0)
458 		return 0;
459 
460 	padding_factor = 0;
461 	if (strlen(filename) % 4 != 0)
462 		padding_factor = 4 - (strlen(filename) % 4);
463 
464 	new_entry_byte_reqd = strlen(filename) +
465 	    sizeof(struct ext2_dirent) + padding_factor;
466 	if (sizeof_void_space >= new_entry_byte_reqd) {
467 		dir->direntlen = cpu_to_le16(dentry_length);
468 		return sizeof_void_space;
469 	}
470 
471 	return 0;
472 }
473 
474 int ext4fs_update_parent_dentry(char *filename, int file_type)
475 {
476 	unsigned int *zero_buffer = NULL;
477 	char *root_first_block_buffer = NULL;
478 	int blk_idx;
479 	long int first_block_no_of_root = 0;
480 	int totalbytes = 0;
481 	unsigned int new_entry_byte_reqd;
482 	int sizeof_void_space = 0;
483 	int templength = 0;
484 	int inodeno = -1;
485 	int status;
486 	struct ext_filesystem *fs = get_fs();
487 	/* directory entry */
488 	struct ext2_dirent *dir;
489 	char *temp_dir = NULL;
490 	uint32_t new_blk_no;
491 	uint32_t new_size;
492 	uint32_t new_blockcnt;
493 	uint32_t directory_blocks;
494 
495 	zero_buffer = zalloc(fs->blksz);
496 	if (!zero_buffer) {
497 		printf("No Memory\n");
498 		return -1;
499 	}
500 	root_first_block_buffer = zalloc(fs->blksz);
501 	if (!root_first_block_buffer) {
502 		free(zero_buffer);
503 		printf("No Memory\n");
504 		return -1;
505 	}
506 	new_entry_byte_reqd = ROUND(strlen(filename) +
507 				    sizeof(struct ext2_dirent), 4);
508 restart:
509 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
510 		LOG2_BLOCK_SIZE(ext4fs_root);
511 	blk_idx = directory_blocks - 1;
512 
513 restart_read:
514 	/* read the block no allocated to a file */
515 	first_block_no_of_root = read_allocated_block(g_parent_inode, blk_idx);
516 	if (first_block_no_of_root <= 0)
517 		goto fail;
518 
519 	status = ext4fs_devread((lbaint_t)first_block_no_of_root
520 				* fs->sect_perblk,
521 				0, fs->blksz, root_first_block_buffer);
522 	if (status == 0)
523 		goto fail;
524 
525 	if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
526 		goto fail;
527 	dir = (struct ext2_dirent *)root_first_block_buffer;
528 	totalbytes = 0;
529 
530 	while (le16_to_cpu(dir->direntlen) > 0) {
531 		unsigned short used_len = ROUND(dir->namelen +
532 		    sizeof(struct ext2_dirent), 4);
533 
534 		/* last entry of block */
535 		if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen)) {
536 
537 			/* check if new entry fits */
538 			if ((used_len + new_entry_byte_reqd) <=
539 			    le16_to_cpu(dir->direntlen)) {
540 				dir->direntlen = cpu_to_le16(used_len);
541 				break;
542 			} else {
543 				if (blk_idx > 0) {
544 					printf("Block full, trying previous\n");
545 					blk_idx--;
546 					goto restart_read;
547 				}
548 				printf("All blocks full: Allocate new\n");
549 
550 				if (le32_to_cpu(g_parent_inode->flags) &
551 						EXT4_EXTENTS_FL) {
552 					printf("Directory uses extents\n");
553 					goto fail;
554 				}
555 				if (directory_blocks >= INDIRECT_BLOCKS) {
556 					printf("Directory exceeds limit\n");
557 					goto fail;
558 				}
559 				new_blk_no = ext4fs_get_new_blk_no();
560 				if (new_blk_no == -1) {
561 					printf("no block left to assign\n");
562 					goto fail;
563 				}
564 				put_ext4((uint64_t)new_blk_no * fs->blksz, zero_buffer, fs->blksz);
565 				g_parent_inode->b.blocks.
566 					dir_blocks[directory_blocks] =
567 					cpu_to_le32(new_blk_no);
568 
569 				new_size = le32_to_cpu(g_parent_inode->size);
570 				new_size += fs->blksz;
571 				g_parent_inode->size = cpu_to_le32(new_size);
572 
573 				new_blockcnt = le32_to_cpu(g_parent_inode->blockcnt);
574 				new_blockcnt += fs->sect_perblk;
575 				g_parent_inode->blockcnt = cpu_to_le32(new_blockcnt);
576 
577 				if (ext4fs_put_metadata
578 				    (root_first_block_buffer,
579 				     first_block_no_of_root))
580 					goto fail;
581 				goto restart;
582 			}
583 		}
584 
585 		templength = le16_to_cpu(dir->direntlen);
586 		totalbytes = totalbytes + templength;
587 		sizeof_void_space = check_void_in_dentry(dir, filename);
588 		if (sizeof_void_space)
589 			break;
590 
591 		dir = (struct ext2_dirent *)((char *)dir + templength);
592 	}
593 
594 	/* make a pointer ready for creating next directory entry */
595 	templength = le16_to_cpu(dir->direntlen);
596 	totalbytes = totalbytes + templength;
597 	dir = (struct ext2_dirent *)((char *)dir + templength);
598 
599 	/* get the next available inode number */
600 	inodeno = ext4fs_get_new_inode_no();
601 	if (inodeno == -1) {
602 		printf("no inode left to assign\n");
603 		goto fail;
604 	}
605 	dir->inode = cpu_to_le32(inodeno);
606 	if (sizeof_void_space)
607 		dir->direntlen = cpu_to_le16(sizeof_void_space);
608 	else
609 		dir->direntlen = cpu_to_le16(fs->blksz - totalbytes);
610 
611 	dir->namelen = strlen(filename);
612 	dir->filetype = FILETYPE_REG;	/* regular file */
613 	temp_dir = (char *)dir;
614 	temp_dir = temp_dir + sizeof(struct ext2_dirent);
615 	memcpy(temp_dir, filename, strlen(filename));
616 
617 	/* update or write  the 1st block of root inode */
618 	if (ext4fs_put_metadata(root_first_block_buffer,
619 				first_block_no_of_root))
620 		goto fail;
621 
622 fail:
623 	free(zero_buffer);
624 	free(root_first_block_buffer);
625 
626 	return inodeno;
627 }
628 
629 static int search_dir(struct ext2_inode *parent_inode, char *dirname)
630 {
631 	int status;
632 	int inodeno = 0;
633 	int offset;
634 	int blk_idx;
635 	long int blknr;
636 	char *block_buffer = NULL;
637 	struct ext2_dirent *dir = NULL;
638 	struct ext_filesystem *fs = get_fs();
639 	uint32_t directory_blocks;
640 	char *direntname;
641 
642 	directory_blocks = le32_to_cpu(parent_inode->size) >>
643 		LOG2_BLOCK_SIZE(ext4fs_root);
644 
645 	block_buffer = zalloc(fs->blksz);
646 	if (!block_buffer)
647 		goto fail;
648 
649 	/* get the block no allocated to a file */
650 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
651 		blknr = read_allocated_block(parent_inode, blk_idx);
652 		if (blknr <= 0)
653 			goto fail;
654 
655 		/* read the directory block */
656 		status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk,
657 					0, fs->blksz, (char *)block_buffer);
658 		if (status == 0)
659 			goto fail;
660 
661 		offset = 0;
662 		do {
663 			dir = (struct ext2_dirent *)(block_buffer + offset);
664 			direntname = (char*)(dir) + sizeof(struct ext2_dirent);
665 
666 			int direntlen = le16_to_cpu(dir->direntlen);
667 			if (direntlen < sizeof(struct ext2_dirent))
668 				break;
669 
670 			if (dir->inode && (strlen(dirname) == dir->namelen) &&
671 			    (strncmp(dirname, direntname, dir->namelen) == 0)) {
672 				inodeno = le32_to_cpu(dir->inode);
673 				break;
674 			}
675 
676 			offset += direntlen;
677 
678 		} while (offset < fs->blksz);
679 
680 		if (inodeno > 0) {
681 			free(block_buffer);
682 			return inodeno;
683 		}
684 	}
685 
686 fail:
687 	free(block_buffer);
688 
689 	return -1;
690 }
691 
692 static int find_dir_depth(char *dirname)
693 {
694 	char *token = strtok(dirname, "/");
695 	int count = 0;
696 	while (token != NULL) {
697 		token = strtok(NULL, "/");
698 		count++;
699 	}
700 	return count + 1 + 1;
701 	/*
702 	 * for example  for string /home/temp
703 	 * depth=home(1)+temp(1)+1 extra for NULL;
704 	 * so count is 4;
705 	 */
706 }
707 
708 static int parse_path(char **arr, char *dirname)
709 {
710 	char *token = strtok(dirname, "/");
711 	int i = 0;
712 
713 	/* add root */
714 	arr[i] = zalloc(strlen("/") + 1);
715 	if (!arr[i])
716 		return -ENOMEM;
717 	memcpy(arr[i++], "/", strlen("/"));
718 
719 	/* add each path entry after root */
720 	while (token != NULL) {
721 		arr[i] = zalloc(strlen(token) + 1);
722 		if (!arr[i])
723 			return -ENOMEM;
724 		memcpy(arr[i++], token, strlen(token));
725 		token = strtok(NULL, "/");
726 	}
727 	arr[i] = NULL;
728 
729 	return 0;
730 }
731 
732 int ext4fs_iget(int inode_no, struct ext2_inode *inode)
733 {
734 	if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0)
735 		return -1;
736 
737 	return 0;
738 }
739 
740 /*
741  * Function: ext4fs_get_parent_inode_num
742  * Return Value: inode Number of the parent directory of  file/Directory to be
743  * created
744  * dirname : Input parmater, input path name of the file/directory to be created
745  * dname : Output parameter, to be filled with the name of the directory
746  * extracted from dirname
747  */
748 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags)
749 {
750 	int i;
751 	int depth = 0;
752 	int matched_inode_no;
753 	int result_inode_no = -1;
754 	char **ptr = NULL;
755 	char *depth_dirname = NULL;
756 	char *parse_dirname = NULL;
757 	struct ext2_inode *parent_inode = NULL;
758 	struct ext2_inode *first_inode = NULL;
759 	struct ext2_inode temp_inode;
760 
761 	if (*dirname != '/') {
762 		printf("Please supply Absolute path\n");
763 		return -1;
764 	}
765 
766 	/* TODO: input validation make equivalent to linux */
767 	depth_dirname = zalloc(strlen(dirname) + 1);
768 	if (!depth_dirname)
769 		return -ENOMEM;
770 
771 	memcpy(depth_dirname, dirname, strlen(dirname));
772 	depth = find_dir_depth(depth_dirname);
773 	parse_dirname = zalloc(strlen(dirname) + 1);
774 	if (!parse_dirname)
775 		goto fail;
776 	memcpy(parse_dirname, dirname, strlen(dirname));
777 
778 	/* allocate memory for each directory level */
779 	ptr = zalloc((depth) * sizeof(char *));
780 	if (!ptr)
781 		goto fail;
782 	if (parse_path(ptr, parse_dirname))
783 		goto fail;
784 	parent_inode = zalloc(sizeof(struct ext2_inode));
785 	if (!parent_inode)
786 		goto fail;
787 	first_inode = zalloc(sizeof(struct ext2_inode));
788 	if (!first_inode)
789 		goto fail;
790 	memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode));
791 	memcpy(first_inode, parent_inode, sizeof(struct ext2_inode));
792 	if (flags & F_FILE)
793 		result_inode_no = EXT2_ROOT_INO;
794 	for (i = 1; i < depth; i++) {
795 		matched_inode_no = search_dir(parent_inode, ptr[i]);
796 		if (matched_inode_no == -1) {
797 			if (ptr[i + 1] == NULL && i == 1) {
798 				result_inode_no = EXT2_ROOT_INO;
799 				goto end;
800 			} else {
801 				if (ptr[i + 1] == NULL)
802 					break;
803 				printf("Invalid path\n");
804 				result_inode_no = -1;
805 				goto fail;
806 			}
807 		} else {
808 			if (ptr[i + 1] != NULL) {
809 				memset(parent_inode, '\0',
810 				       sizeof(struct ext2_inode));
811 				if (ext4fs_iget(matched_inode_no,
812 						parent_inode)) {
813 					result_inode_no = -1;
814 					goto fail;
815 				}
816 				result_inode_no = matched_inode_no;
817 			} else {
818 				break;
819 			}
820 		}
821 	}
822 
823 end:
824 	if (i == 1)
825 		matched_inode_no = search_dir(first_inode, ptr[i]);
826 	else
827 		matched_inode_no = search_dir(parent_inode, ptr[i]);
828 
829 	if (matched_inode_no != -1) {
830 		ext4fs_iget(matched_inode_no, &temp_inode);
831 		if (le16_to_cpu(temp_inode.mode) & S_IFDIR) {
832 			printf("It is a Directory\n");
833 			result_inode_no = -1;
834 			goto fail;
835 		}
836 	}
837 
838 	if (strlen(ptr[i]) > 256) {
839 		result_inode_no = -1;
840 		goto fail;
841 	}
842 	memcpy(dname, ptr[i], strlen(ptr[i]));
843 
844 fail:
845 	free(depth_dirname);
846 	free(parse_dirname);
847 	for (i = 0; i < depth; i++) {
848 		if (!ptr[i])
849 			break;
850 		free(ptr[i]);
851 	}
852 	free(ptr);
853 	free(parent_inode);
854 	free(first_inode);
855 
856 	return result_inode_no;
857 }
858 
859 static int unlink_filename(char *filename, unsigned int blknr)
860 {
861 	int status;
862 	int inodeno = 0;
863 	int offset;
864 	char *block_buffer = NULL;
865 	struct ext2_dirent *dir = NULL;
866 	struct ext2_dirent *previous_dir;
867 	struct ext_filesystem *fs = get_fs();
868 	int ret = -1;
869 	char *direntname;
870 
871 	block_buffer = zalloc(fs->blksz);
872 	if (!block_buffer)
873 		return -ENOMEM;
874 
875 	/* read the directory block */
876 	status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0,
877 				fs->blksz, block_buffer);
878 	if (status == 0)
879 		goto fail;
880 
881 	offset = 0;
882 	do {
883 		previous_dir = dir;
884 		dir = (struct ext2_dirent *)(block_buffer + offset);
885 		direntname = (char *)(dir) + sizeof(struct ext2_dirent);
886 
887 		int direntlen = le16_to_cpu(dir->direntlen);
888 		if (direntlen < sizeof(struct ext2_dirent))
889 			break;
890 
891 		if (dir->inode && (strlen(filename) == dir->namelen) &&
892 		    (strncmp(direntname, filename, dir->namelen) == 0)) {
893 			inodeno = le32_to_cpu(dir->inode);
894 			break;
895 		}
896 
897 		offset += direntlen;
898 
899 	} while (offset < fs->blksz);
900 
901 	if (inodeno > 0) {
902 		printf("file found, deleting\n");
903 		if (ext4fs_log_journal(block_buffer, blknr))
904 			goto fail;
905 
906 		if (previous_dir) {
907 			/* merge dir entry with predecessor */
908 			uint16_t new_len;
909 			new_len = le16_to_cpu(previous_dir->direntlen);
910 			new_len += le16_to_cpu(dir->direntlen);
911 			previous_dir->direntlen = cpu_to_le16(new_len);
912 		} else {
913 			/* invalidate dir entry */
914 			dir->inode = 0;
915 		}
916 		if (ext4fs_put_metadata(block_buffer, blknr))
917 			goto fail;
918 		ret = inodeno;
919 	}
920 fail:
921 	free(block_buffer);
922 
923 	return ret;
924 }
925 
926 int ext4fs_filename_unlink(char *filename)
927 {
928 	int blk_idx;
929 	long int blknr = -1;
930 	int inodeno = -1;
931 	uint32_t directory_blocks;
932 
933 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
934 		LOG2_BLOCK_SIZE(ext4fs_root);
935 
936 	/* read the block no allocated to a file */
937 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
938 		blknr = read_allocated_block(g_parent_inode, blk_idx);
939 		if (blknr <= 0)
940 			break;
941 		inodeno = unlink_filename(filename, blknr);
942 		if (inodeno != -1)
943 			return inodeno;
944 	}
945 
946 	return -1;
947 }
948 
949 uint32_t ext4fs_get_new_blk_no(void)
950 {
951 	short i;
952 	short status;
953 	int remainder;
954 	unsigned int bg_idx;
955 	static int prev_bg_bitmap_index = -1;
956 	unsigned int blk_per_grp = le32_to_cpu(ext4fs_root->sblock.blocks_per_group);
957 	struct ext_filesystem *fs = get_fs();
958 	char *journal_buffer = zalloc(fs->blksz);
959 	char *zero_buffer = zalloc(fs->blksz);
960 	if (!journal_buffer || !zero_buffer)
961 		goto fail;
962 
963 	if (fs->first_pass_bbmap == 0) {
964 		for (i = 0; i < fs->no_blkgrp; i++) {
965 			struct ext2_block_group *bgd = NULL;
966 			bgd = ext4fs_get_group_descriptor(fs, i);
967 			if (ext4fs_bg_get_free_blocks(bgd, fs)) {
968 				uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
969 				uint64_t b_bitmap_blk =
970 					ext4fs_bg_get_block_id(bgd, fs);
971 				if (bg_flags & EXT4_BG_BLOCK_UNINIT) {
972 					memcpy(fs->blk_bmaps[i], zero_buffer,
973 					       fs->blksz);
974 					put_ext4(b_bitmap_blk * fs->blksz,
975 						 fs->blk_bmaps[i], fs->blksz);
976 					bg_flags &= ~EXT4_BG_BLOCK_UNINIT;
977 					ext4fs_bg_set_flags(bgd, bg_flags);
978 				}
979 				fs->curr_blkno =
980 				    _get_new_blk_no(fs->blk_bmaps[i]);
981 				if (fs->curr_blkno == -1)
982 					/* block bitmap is completely filled */
983 					continue;
984 				fs->curr_blkno = fs->curr_blkno +
985 						(i * fs->blksz * 8);
986 				fs->first_pass_bbmap++;
987 				ext4fs_bg_free_blocks_dec(bgd, fs);
988 				ext4fs_sb_free_blocks_dec(fs->sb);
989 				status = ext4fs_devread(b_bitmap_blk *
990 							fs->sect_perblk,
991 							0, fs->blksz,
992 							journal_buffer);
993 				if (status == 0)
994 					goto fail;
995 				if (ext4fs_log_journal(journal_buffer,
996 						       b_bitmap_blk))
997 					goto fail;
998 				goto success;
999 			} else {
1000 				debug("no space left on block group %d\n", i);
1001 			}
1002 		}
1003 
1004 		goto fail;
1005 	} else {
1006 		fs->curr_blkno++;
1007 restart:
1008 		/* get the blockbitmap index respective to blockno */
1009 		bg_idx = fs->curr_blkno / blk_per_grp;
1010 		if (fs->blksz == 1024) {
1011 			remainder = fs->curr_blkno % blk_per_grp;
1012 			if (!remainder)
1013 				bg_idx--;
1014 		}
1015 
1016 		/*
1017 		 * To skip completely filled block group bitmaps
1018 		 * Optimize the block allocation
1019 		 */
1020 		if (bg_idx >= fs->no_blkgrp)
1021 			goto fail;
1022 
1023 		struct ext2_block_group *bgd = NULL;
1024 		bgd = ext4fs_get_group_descriptor(fs, bg_idx);
1025 		if (ext4fs_bg_get_free_blocks(bgd, fs) == 0) {
1026 			debug("block group %u is full. Skipping\n", bg_idx);
1027 			fs->curr_blkno = (bg_idx + 1) * blk_per_grp;
1028 			if (fs->blksz == 1024)
1029 				fs->curr_blkno += 1;
1030 			goto restart;
1031 		}
1032 
1033 		uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1034 		uint64_t b_bitmap_blk = ext4fs_bg_get_block_id(bgd, fs);
1035 		if (bg_flags & EXT4_BG_BLOCK_UNINIT) {
1036 			memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz);
1037 			put_ext4(b_bitmap_blk * fs->blksz,
1038 				 zero_buffer, fs->blksz);
1039 			bg_flags &= ~EXT4_BG_BLOCK_UNINIT;
1040 			ext4fs_bg_set_flags(bgd, bg_flags);
1041 		}
1042 
1043 		if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx],
1044 				   bg_idx) != 0) {
1045 			debug("going for restart for the block no %ld %u\n",
1046 			      fs->curr_blkno, bg_idx);
1047 			fs->curr_blkno++;
1048 			goto restart;
1049 		}
1050 
1051 		/* journal backup */
1052 		if (prev_bg_bitmap_index != bg_idx) {
1053 			status = ext4fs_devread(b_bitmap_blk * fs->sect_perblk,
1054 						0, fs->blksz, journal_buffer);
1055 			if (status == 0)
1056 				goto fail;
1057 			if (ext4fs_log_journal(journal_buffer, b_bitmap_blk))
1058 				goto fail;
1059 
1060 			prev_bg_bitmap_index = bg_idx;
1061 		}
1062 		ext4fs_bg_free_blocks_dec(bgd, fs);
1063 		ext4fs_sb_free_blocks_dec(fs->sb);
1064 		goto success;
1065 	}
1066 success:
1067 	free(journal_buffer);
1068 	free(zero_buffer);
1069 
1070 	return fs->curr_blkno;
1071 fail:
1072 	free(journal_buffer);
1073 	free(zero_buffer);
1074 
1075 	return -1;
1076 }
1077 
1078 int ext4fs_get_new_inode_no(void)
1079 {
1080 	short i;
1081 	short status;
1082 	unsigned int ibmap_idx;
1083 	static int prev_inode_bitmap_index = -1;
1084 	unsigned int inodes_per_grp = le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
1085 	struct ext_filesystem *fs = get_fs();
1086 	char *journal_buffer = zalloc(fs->blksz);
1087 	char *zero_buffer = zalloc(fs->blksz);
1088 	if (!journal_buffer || !zero_buffer)
1089 		goto fail;
1090 	int has_gdt_chksum = le32_to_cpu(fs->sb->feature_ro_compat) &
1091 		EXT4_FEATURE_RO_COMPAT_GDT_CSUM ? 1 : 0;
1092 
1093 	if (fs->first_pass_ibmap == 0) {
1094 		for (i = 0; i < fs->no_blkgrp; i++) {
1095 			uint32_t free_inodes;
1096 			struct ext2_block_group *bgd = NULL;
1097 			bgd = ext4fs_get_group_descriptor(fs, i);
1098 			free_inodes = ext4fs_bg_get_free_inodes(bgd, fs);
1099 			if (free_inodes) {
1100 				uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1101 				uint64_t i_bitmap_blk =
1102 					ext4fs_bg_get_inode_id(bgd, fs);
1103 				if (has_gdt_chksum)
1104 					bgd->bg_itable_unused = free_inodes;
1105 				if (bg_flags & EXT4_BG_INODE_UNINIT) {
1106 					put_ext4(i_bitmap_blk * fs->blksz,
1107 						 zero_buffer, fs->blksz);
1108 					bg_flags &= ~EXT4_BG_INODE_UNINIT;
1109 					ext4fs_bg_set_flags(bgd, bg_flags);
1110 					memcpy(fs->inode_bmaps[i],
1111 					       zero_buffer, fs->blksz);
1112 				}
1113 				fs->curr_inode_no =
1114 				    _get_new_inode_no(fs->inode_bmaps[i]);
1115 				if (fs->curr_inode_no == -1)
1116 					/* inode bitmap is completely filled */
1117 					continue;
1118 				fs->curr_inode_no = fs->curr_inode_no +
1119 							(i * inodes_per_grp);
1120 				fs->first_pass_ibmap++;
1121 				ext4fs_bg_free_inodes_dec(bgd, fs);
1122 				if (has_gdt_chksum)
1123 					ext4fs_bg_itable_unused_dec(bgd, fs);
1124 				ext4fs_sb_free_inodes_dec(fs->sb);
1125 				status = ext4fs_devread(i_bitmap_blk *
1126 							fs->sect_perblk,
1127 							0, fs->blksz,
1128 							journal_buffer);
1129 				if (status == 0)
1130 					goto fail;
1131 				if (ext4fs_log_journal(journal_buffer,
1132 						       i_bitmap_blk))
1133 					goto fail;
1134 				goto success;
1135 			} else
1136 				debug("no inode left on block group %d\n", i);
1137 		}
1138 		goto fail;
1139 	} else {
1140 restart:
1141 		fs->curr_inode_no++;
1142 		/* get the blockbitmap index respective to blockno */
1143 		ibmap_idx = fs->curr_inode_no / inodes_per_grp;
1144 		struct ext2_block_group *bgd =
1145 			ext4fs_get_group_descriptor(fs, ibmap_idx);
1146 		uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1147 		uint64_t i_bitmap_blk = ext4fs_bg_get_inode_id(bgd, fs);
1148 
1149 		if (bg_flags & EXT4_BG_INODE_UNINIT) {
1150 			put_ext4(i_bitmap_blk * fs->blksz,
1151 				 zero_buffer, fs->blksz);
1152 			bg_flags &= ~EXT4_BG_INODE_UNINIT;
1153 			ext4fs_bg_set_flags(bgd, bg_flags);
1154 			memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer,
1155 				fs->blksz);
1156 		}
1157 
1158 		if (ext4fs_set_inode_bmap(fs->curr_inode_no,
1159 					  fs->inode_bmaps[ibmap_idx],
1160 					  ibmap_idx) != 0) {
1161 			debug("going for restart for the block no %d %u\n",
1162 			      fs->curr_inode_no, ibmap_idx);
1163 			goto restart;
1164 		}
1165 
1166 		/* journal backup */
1167 		if (prev_inode_bitmap_index != ibmap_idx) {
1168 			status = ext4fs_devread(i_bitmap_blk * fs->sect_perblk,
1169 						0, fs->blksz, journal_buffer);
1170 			if (status == 0)
1171 				goto fail;
1172 			if (ext4fs_log_journal(journal_buffer,
1173 						le32_to_cpu(bgd->inode_id)))
1174 				goto fail;
1175 			prev_inode_bitmap_index = ibmap_idx;
1176 		}
1177 		ext4fs_bg_free_inodes_dec(bgd, fs);
1178 		if (has_gdt_chksum)
1179 			bgd->bg_itable_unused = bgd->free_inodes;
1180 		ext4fs_sb_free_inodes_dec(fs->sb);
1181 		goto success;
1182 	}
1183 
1184 success:
1185 	free(journal_buffer);
1186 	free(zero_buffer);
1187 
1188 	return fs->curr_inode_no;
1189 fail:
1190 	free(journal_buffer);
1191 	free(zero_buffer);
1192 
1193 	return -1;
1194 
1195 }
1196 
1197 
1198 static void alloc_single_indirect_block(struct ext2_inode *file_inode,
1199 					unsigned int *total_remaining_blocks,
1200 					unsigned int *no_blks_reqd)
1201 {
1202 	short i;
1203 	short status;
1204 	long int actual_block_no;
1205 	long int si_blockno;
1206 	/* si :single indirect */
1207 	__le32 *si_buffer = NULL;
1208 	__le32 *si_start_addr = NULL;
1209 	struct ext_filesystem *fs = get_fs();
1210 
1211 	if (*total_remaining_blocks != 0) {
1212 		si_buffer = zalloc(fs->blksz);
1213 		if (!si_buffer) {
1214 			printf("No Memory\n");
1215 			return;
1216 		}
1217 		si_start_addr = si_buffer;
1218 		si_blockno = ext4fs_get_new_blk_no();
1219 		if (si_blockno == -1) {
1220 			printf("no block left to assign\n");
1221 			goto fail;
1222 		}
1223 		(*no_blks_reqd)++;
1224 		debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks);
1225 
1226 		status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk,
1227 					0, fs->blksz, (char *)si_buffer);
1228 		memset(si_buffer, '\0', fs->blksz);
1229 		if (status == 0)
1230 			goto fail;
1231 
1232 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1233 			actual_block_no = ext4fs_get_new_blk_no();
1234 			if (actual_block_no == -1) {
1235 				printf("no block left to assign\n");
1236 				goto fail;
1237 			}
1238 			*si_buffer = cpu_to_le32(actual_block_no);
1239 			debug("SIAB %u: %u\n", *si_buffer,
1240 				*total_remaining_blocks);
1241 
1242 			si_buffer++;
1243 			(*total_remaining_blocks)--;
1244 			if (*total_remaining_blocks == 0)
1245 				break;
1246 		}
1247 
1248 		/* write the block to disk */
1249 		put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)),
1250 			 si_start_addr, fs->blksz);
1251 		file_inode->b.blocks.indir_block = cpu_to_le32(si_blockno);
1252 	}
1253 fail:
1254 	free(si_start_addr);
1255 }
1256 
1257 static void alloc_double_indirect_block(struct ext2_inode *file_inode,
1258 					unsigned int *total_remaining_blocks,
1259 					unsigned int *no_blks_reqd)
1260 {
1261 	short i;
1262 	short j;
1263 	short status;
1264 	long int actual_block_no;
1265 	/* di:double indirect */
1266 	long int di_blockno_parent;
1267 	long int di_blockno_child;
1268 	__le32 *di_parent_buffer = NULL;
1269 	__le32 *di_child_buff = NULL;
1270 	__le32 *di_block_start_addr = NULL;
1271 	__le32 *di_child_buff_start = NULL;
1272 	struct ext_filesystem *fs = get_fs();
1273 
1274 	if (*total_remaining_blocks != 0) {
1275 		/* double indirect parent block connecting to inode */
1276 		di_blockno_parent = ext4fs_get_new_blk_no();
1277 		if (di_blockno_parent == -1) {
1278 			printf("no block left to assign\n");
1279 			goto fail;
1280 		}
1281 		di_parent_buffer = zalloc(fs->blksz);
1282 		if (!di_parent_buffer)
1283 			goto fail;
1284 
1285 		di_block_start_addr = di_parent_buffer;
1286 		(*no_blks_reqd)++;
1287 		debug("DIPB %ld: %u\n", di_blockno_parent,
1288 		      *total_remaining_blocks);
1289 
1290 		status = ext4fs_devread((lbaint_t)di_blockno_parent *
1291 					fs->sect_perblk, 0,
1292 					fs->blksz, (char *)di_parent_buffer);
1293 
1294 		if (!status) {
1295 			printf("%s: Device read error!\n", __func__);
1296 			goto fail;
1297 		}
1298 		memset(di_parent_buffer, '\0', fs->blksz);
1299 
1300 		/*
1301 		 * start:for each double indirect parent
1302 		 * block create one more block
1303 		 */
1304 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1305 			di_blockno_child = ext4fs_get_new_blk_no();
1306 			if (di_blockno_child == -1) {
1307 				printf("no block left to assign\n");
1308 				goto fail;
1309 			}
1310 			di_child_buff = zalloc(fs->blksz);
1311 			if (!di_child_buff)
1312 				goto fail;
1313 
1314 			di_child_buff_start = di_child_buff;
1315 			*di_parent_buffer = cpu_to_le32(di_blockno_child);
1316 			di_parent_buffer++;
1317 			(*no_blks_reqd)++;
1318 			debug("DICB %ld: %u\n", di_blockno_child,
1319 			      *total_remaining_blocks);
1320 
1321 			status = ext4fs_devread((lbaint_t)di_blockno_child *
1322 						fs->sect_perblk, 0,
1323 						fs->blksz,
1324 						(char *)di_child_buff);
1325 
1326 			if (!status) {
1327 				printf("%s: Device read error!\n", __func__);
1328 				goto fail;
1329 			}
1330 			memset(di_child_buff, '\0', fs->blksz);
1331 			/* filling of actual datablocks for each child */
1332 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1333 				actual_block_no = ext4fs_get_new_blk_no();
1334 				if (actual_block_no == -1) {
1335 					printf("no block left to assign\n");
1336 					goto fail;
1337 				}
1338 				*di_child_buff = cpu_to_le32(actual_block_no);
1339 				debug("DIAB %ld: %u\n", actual_block_no,
1340 				      *total_remaining_blocks);
1341 
1342 				di_child_buff++;
1343 				(*total_remaining_blocks)--;
1344 				if (*total_remaining_blocks == 0)
1345 					break;
1346 			}
1347 			/* write the block  table */
1348 			put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)),
1349 				 di_child_buff_start, fs->blksz);
1350 			free(di_child_buff_start);
1351 			di_child_buff_start = NULL;
1352 
1353 			if (*total_remaining_blocks == 0)
1354 				break;
1355 		}
1356 		put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)),
1357 			 di_block_start_addr, fs->blksz);
1358 		file_inode->b.blocks.double_indir_block = cpu_to_le32(di_blockno_parent);
1359 	}
1360 fail:
1361 	free(di_block_start_addr);
1362 }
1363 
1364 static void alloc_triple_indirect_block(struct ext2_inode *file_inode,
1365 					unsigned int *total_remaining_blocks,
1366 					unsigned int *no_blks_reqd)
1367 {
1368 	short i;
1369 	short j;
1370 	short k;
1371 	long int actual_block_no;
1372 	/* ti: Triple Indirect */
1373 	long int ti_gp_blockno;
1374 	long int ti_parent_blockno;
1375 	long int ti_child_blockno;
1376 	__le32 *ti_gp_buff = NULL;
1377 	__le32 *ti_parent_buff = NULL;
1378 	__le32 *ti_child_buff = NULL;
1379 	__le32 *ti_gp_buff_start_addr = NULL;
1380 	__le32 *ti_pbuff_start_addr = NULL;
1381 	__le32 *ti_cbuff_start_addr = NULL;
1382 	struct ext_filesystem *fs = get_fs();
1383 	if (*total_remaining_blocks != 0) {
1384 		/* triple indirect grand parent block connecting to inode */
1385 		ti_gp_blockno = ext4fs_get_new_blk_no();
1386 		if (ti_gp_blockno == -1) {
1387 			printf("no block left to assign\n");
1388 			return;
1389 		}
1390 		ti_gp_buff = zalloc(fs->blksz);
1391 		if (!ti_gp_buff)
1392 			return;
1393 
1394 		ti_gp_buff_start_addr = ti_gp_buff;
1395 		(*no_blks_reqd)++;
1396 		debug("TIGPB %ld: %u\n", ti_gp_blockno,
1397 		      *total_remaining_blocks);
1398 
1399 		/* for each 4 byte grand parent entry create one more block */
1400 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1401 			ti_parent_blockno = ext4fs_get_new_blk_no();
1402 			if (ti_parent_blockno == -1) {
1403 				printf("no block left to assign\n");
1404 				goto fail;
1405 			}
1406 			ti_parent_buff = zalloc(fs->blksz);
1407 			if (!ti_parent_buff)
1408 				goto fail;
1409 
1410 			ti_pbuff_start_addr = ti_parent_buff;
1411 			*ti_gp_buff = cpu_to_le32(ti_parent_blockno);
1412 			ti_gp_buff++;
1413 			(*no_blks_reqd)++;
1414 			debug("TIPB %ld: %u\n", ti_parent_blockno,
1415 			      *total_remaining_blocks);
1416 
1417 			/* for each 4 byte entry parent create one more block */
1418 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1419 				ti_child_blockno = ext4fs_get_new_blk_no();
1420 				if (ti_child_blockno == -1) {
1421 					printf("no block left assign\n");
1422 					goto fail1;
1423 				}
1424 				ti_child_buff = zalloc(fs->blksz);
1425 				if (!ti_child_buff)
1426 					goto fail1;
1427 
1428 				ti_cbuff_start_addr = ti_child_buff;
1429 				*ti_parent_buff = cpu_to_le32(ti_child_blockno);
1430 				ti_parent_buff++;
1431 				(*no_blks_reqd)++;
1432 				debug("TICB %ld: %u\n", ti_parent_blockno,
1433 				      *total_remaining_blocks);
1434 
1435 				/* fill actual datablocks for each child */
1436 				for (k = 0; k < (fs->blksz / sizeof(int));
1437 					k++) {
1438 					actual_block_no =
1439 					    ext4fs_get_new_blk_no();
1440 					if (actual_block_no == -1) {
1441 						printf("no block left\n");
1442 						free(ti_cbuff_start_addr);
1443 						goto fail1;
1444 					}
1445 					*ti_child_buff = cpu_to_le32(actual_block_no);
1446 					debug("TIAB %ld: %u\n", actual_block_no,
1447 					      *total_remaining_blocks);
1448 
1449 					ti_child_buff++;
1450 					(*total_remaining_blocks)--;
1451 					if (*total_remaining_blocks == 0)
1452 						break;
1453 				}
1454 				/* write the child block */
1455 				put_ext4(((uint64_t) ((uint64_t)ti_child_blockno *
1456 						      (uint64_t)fs->blksz)),
1457 					 ti_cbuff_start_addr, fs->blksz);
1458 				free(ti_cbuff_start_addr);
1459 
1460 				if (*total_remaining_blocks == 0)
1461 					break;
1462 			}
1463 			/* write the parent block */
1464 			put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)),
1465 				 ti_pbuff_start_addr, fs->blksz);
1466 			free(ti_pbuff_start_addr);
1467 
1468 			if (*total_remaining_blocks == 0)
1469 				break;
1470 		}
1471 		/* write the grand parent block */
1472 		put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)),
1473 			 ti_gp_buff_start_addr, fs->blksz);
1474 		file_inode->b.blocks.triple_indir_block = cpu_to_le32(ti_gp_blockno);
1475 		free(ti_gp_buff_start_addr);
1476 		return;
1477 	}
1478 fail1:
1479 	free(ti_pbuff_start_addr);
1480 fail:
1481 	free(ti_gp_buff_start_addr);
1482 }
1483 
1484 void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
1485 				unsigned int total_remaining_blocks,
1486 				unsigned int *total_no_of_block)
1487 {
1488 	short i;
1489 	long int direct_blockno;
1490 	unsigned int no_blks_reqd = 0;
1491 
1492 	/* allocation of direct blocks */
1493 	for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) {
1494 		direct_blockno = ext4fs_get_new_blk_no();
1495 		if (direct_blockno == -1) {
1496 			printf("no block left to assign\n");
1497 			return;
1498 		}
1499 		file_inode->b.blocks.dir_blocks[i] = cpu_to_le32(direct_blockno);
1500 		debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);
1501 
1502 		total_remaining_blocks--;
1503 	}
1504 
1505 	alloc_single_indirect_block(file_inode, &total_remaining_blocks,
1506 				    &no_blks_reqd);
1507 	alloc_double_indirect_block(file_inode, &total_remaining_blocks,
1508 				    &no_blks_reqd);
1509 	alloc_triple_indirect_block(file_inode, &total_remaining_blocks,
1510 				    &no_blks_reqd);
1511 	*total_no_of_block += no_blks_reqd;
1512 }
1513 
1514 #endif
1515 
1516 static struct ext4_extent_header *ext4fs_get_extent_block
1517 	(struct ext2_data *data, char *buf,
1518 		struct ext4_extent_header *ext_block,
1519 		uint32_t fileblock, int log2_blksz)
1520 {
1521 	struct ext4_extent_idx *index;
1522 	unsigned long long block;
1523 	int blksz = EXT2_BLOCK_SIZE(data);
1524 	int i;
1525 
1526 	while (1) {
1527 		index = (struct ext4_extent_idx *)(ext_block + 1);
1528 
1529 		if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
1530 			return NULL;
1531 
1532 		if (ext_block->eh_depth == 0)
1533 			return ext_block;
1534 		i = -1;
1535 		do {
1536 			i++;
1537 			if (i >= le16_to_cpu(ext_block->eh_entries))
1538 				break;
1539 		} while (fileblock >= le32_to_cpu(index[i].ei_block));
1540 
1541 		if (--i < 0)
1542 			return NULL;
1543 
1544 		block = le16_to_cpu(index[i].ei_leaf_hi);
1545 		block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
1546 
1547 		if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz,
1548 				   buf))
1549 			ext_block = (struct ext4_extent_header *)buf;
1550 		else
1551 			return NULL;
1552 	}
1553 }
1554 
1555 static int ext4fs_blockgroup
1556 	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
1557 {
1558 	long int blkno;
1559 	unsigned int blkoff, desc_per_blk;
1560 	int log2blksz = get_fs()->dev_desc->log2blksz;
1561 	int desc_size = get_fs()->gdsize;
1562 
1563 	desc_per_blk = EXT2_BLOCK_SIZE(data) / desc_size;
1564 
1565 	blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
1566 			group / desc_per_blk;
1567 	blkoff = (group % desc_per_blk) * desc_size;
1568 
1569 	debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
1570 	      group, blkno, blkoff);
1571 
1572 	return ext4fs_devread((lbaint_t)blkno <<
1573 			      (LOG2_BLOCK_SIZE(data) - log2blksz),
1574 			      blkoff, desc_size, (char *)blkgrp);
1575 }
1576 
1577 int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
1578 {
1579 	struct ext2_block_group blkgrp;
1580 	struct ext2_sblock *sblock = &data->sblock;
1581 	struct ext_filesystem *fs = get_fs();
1582 	int log2blksz = get_fs()->dev_desc->log2blksz;
1583 	int inodes_per_block, status;
1584 	long int blkno;
1585 	unsigned int blkoff;
1586 
1587 	/* It is easier to calculate if the first inode is 0. */
1588 	ino--;
1589 	status = ext4fs_blockgroup(data, ino / le32_to_cpu
1590 				   (sblock->inodes_per_group), &blkgrp);
1591 	if (status == 0)
1592 		return 0;
1593 
1594 	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
1595 	blkno = ext4fs_bg_get_inode_table_id(&blkgrp, fs) +
1596 	    (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1597 	blkoff = (ino % inodes_per_block) * fs->inodesz;
1598 	/* Read the inode. */
1599 	status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) -
1600 				log2blksz), blkoff,
1601 				sizeof(struct ext2_inode), (char *)inode);
1602 	if (status == 0)
1603 		return 0;
1604 
1605 	return 1;
1606 }
1607 
1608 long int read_allocated_block(struct ext2_inode *inode, int fileblock)
1609 {
1610 	long int blknr;
1611 	int blksz;
1612 	int log2_blksz;
1613 	int status;
1614 	long int rblock;
1615 	long int perblock_parent;
1616 	long int perblock_child;
1617 	unsigned long long start;
1618 	/* get the blocksize of the filesystem */
1619 	blksz = EXT2_BLOCK_SIZE(ext4fs_root);
1620 	log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
1621 		- get_fs()->dev_desc->log2blksz;
1622 
1623 	if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
1624 		long int startblock, endblock;
1625 		char *buf = zalloc(blksz);
1626 		if (!buf)
1627 			return -ENOMEM;
1628 		struct ext4_extent_header *ext_block;
1629 		struct ext4_extent *extent;
1630 		int i;
1631 		ext_block =
1632 			ext4fs_get_extent_block(ext4fs_root, buf,
1633 						(struct ext4_extent_header *)
1634 						inode->b.blocks.dir_blocks,
1635 						fileblock, log2_blksz);
1636 		if (!ext_block) {
1637 			printf("invalid extent block\n");
1638 			free(buf);
1639 			return -EINVAL;
1640 		}
1641 
1642 		extent = (struct ext4_extent *)(ext_block + 1);
1643 
1644 		for (i = 0; i < le16_to_cpu(ext_block->eh_entries); i++) {
1645 			startblock = le32_to_cpu(extent[i].ee_block);
1646 			endblock = startblock + le16_to_cpu(extent[i].ee_len);
1647 
1648 			if (startblock > fileblock) {
1649 				/* Sparse file */
1650 				free(buf);
1651 				return 0;
1652 
1653 			} else if (fileblock < endblock) {
1654 				start = le16_to_cpu(extent[i].ee_start_hi);
1655 				start = (start << 32) +
1656 					le32_to_cpu(extent[i].ee_start_lo);
1657 				free(buf);
1658 				return (fileblock - startblock) + start;
1659 			}
1660 		}
1661 
1662 		free(buf);
1663 		return 0;
1664 	}
1665 
1666 	/* Direct blocks. */
1667 	if (fileblock < INDIRECT_BLOCKS)
1668 		blknr = le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
1669 
1670 	/* Indirect. */
1671 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
1672 		if (ext4fs_indir1_block == NULL) {
1673 			ext4fs_indir1_block = zalloc(blksz);
1674 			if (ext4fs_indir1_block == NULL) {
1675 				printf("** SI ext2fs read block (indir 1)"
1676 					"malloc failed. **\n");
1677 				return -1;
1678 			}
1679 			ext4fs_indir1_size = blksz;
1680 			ext4fs_indir1_blkno = -1;
1681 		}
1682 		if (blksz != ext4fs_indir1_size) {
1683 			free(ext4fs_indir1_block);
1684 			ext4fs_indir1_block = NULL;
1685 			ext4fs_indir1_size = 0;
1686 			ext4fs_indir1_blkno = -1;
1687 			ext4fs_indir1_block = zalloc(blksz);
1688 			if (ext4fs_indir1_block == NULL) {
1689 				printf("** SI ext2fs read block (indir 1):"
1690 					"malloc failed. **\n");
1691 				return -1;
1692 			}
1693 			ext4fs_indir1_size = blksz;
1694 		}
1695 		if ((le32_to_cpu(inode->b.blocks.indir_block) <<
1696 		     log2_blksz) != ext4fs_indir1_blkno) {
1697 			status =
1698 			    ext4fs_devread((lbaint_t)le32_to_cpu
1699 					   (inode->b.blocks.
1700 					    indir_block) << log2_blksz, 0,
1701 					   blksz, (char *)ext4fs_indir1_block);
1702 			if (status == 0) {
1703 				printf("** SI ext2fs read block (indir 1)"
1704 					"failed. **\n");
1705 				return -1;
1706 			}
1707 			ext4fs_indir1_blkno =
1708 				le32_to_cpu(inode->b.blocks.
1709 					       indir_block) << log2_blksz;
1710 		}
1711 		blknr = le32_to_cpu(ext4fs_indir1_block
1712 				      [fileblock - INDIRECT_BLOCKS]);
1713 	}
1714 	/* Double indirect. */
1715 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
1716 					(blksz / 4 + 1)))) {
1717 
1718 		long int perblock = blksz / 4;
1719 		long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
1720 
1721 		if (ext4fs_indir1_block == NULL) {
1722 			ext4fs_indir1_block = zalloc(blksz);
1723 			if (ext4fs_indir1_block == NULL) {
1724 				printf("** DI ext2fs read block (indir 2 1)"
1725 					"malloc failed. **\n");
1726 				return -1;
1727 			}
1728 			ext4fs_indir1_size = blksz;
1729 			ext4fs_indir1_blkno = -1;
1730 		}
1731 		if (blksz != ext4fs_indir1_size) {
1732 			free(ext4fs_indir1_block);
1733 			ext4fs_indir1_block = NULL;
1734 			ext4fs_indir1_size = 0;
1735 			ext4fs_indir1_blkno = -1;
1736 			ext4fs_indir1_block = zalloc(blksz);
1737 			if (ext4fs_indir1_block == NULL) {
1738 				printf("** DI ext2fs read block (indir 2 1)"
1739 					"malloc failed. **\n");
1740 				return -1;
1741 			}
1742 			ext4fs_indir1_size = blksz;
1743 		}
1744 		if ((le32_to_cpu(inode->b.blocks.double_indir_block) <<
1745 		     log2_blksz) != ext4fs_indir1_blkno) {
1746 			status =
1747 			    ext4fs_devread((lbaint_t)le32_to_cpu
1748 					   (inode->b.blocks.
1749 					    double_indir_block) << log2_blksz,
1750 					   0, blksz,
1751 					   (char *)ext4fs_indir1_block);
1752 			if (status == 0) {
1753 				printf("** DI ext2fs read block (indir 2 1)"
1754 					"failed. **\n");
1755 				return -1;
1756 			}
1757 			ext4fs_indir1_blkno =
1758 			    le32_to_cpu(inode->b.blocks.double_indir_block) <<
1759 			    log2_blksz;
1760 		}
1761 
1762 		if (ext4fs_indir2_block == NULL) {
1763 			ext4fs_indir2_block = zalloc(blksz);
1764 			if (ext4fs_indir2_block == NULL) {
1765 				printf("** DI ext2fs read block (indir 2 2)"
1766 					"malloc failed. **\n");
1767 				return -1;
1768 			}
1769 			ext4fs_indir2_size = blksz;
1770 			ext4fs_indir2_blkno = -1;
1771 		}
1772 		if (blksz != ext4fs_indir2_size) {
1773 			free(ext4fs_indir2_block);
1774 			ext4fs_indir2_block = NULL;
1775 			ext4fs_indir2_size = 0;
1776 			ext4fs_indir2_blkno = -1;
1777 			ext4fs_indir2_block = zalloc(blksz);
1778 			if (ext4fs_indir2_block == NULL) {
1779 				printf("** DI ext2fs read block (indir 2 2)"
1780 					"malloc failed. **\n");
1781 				return -1;
1782 			}
1783 			ext4fs_indir2_size = blksz;
1784 		}
1785 		if ((le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
1786 		     log2_blksz) != ext4fs_indir2_blkno) {
1787 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1788 						(ext4fs_indir1_block
1789 						 [rblock /
1790 						  perblock]) << log2_blksz, 0,
1791 						blksz,
1792 						(char *)ext4fs_indir2_block);
1793 			if (status == 0) {
1794 				printf("** DI ext2fs read block (indir 2 2)"
1795 					"failed. **\n");
1796 				return -1;
1797 			}
1798 			ext4fs_indir2_blkno =
1799 			    le32_to_cpu(ext4fs_indir1_block[rblock
1800 							      /
1801 							      perblock]) <<
1802 			    log2_blksz;
1803 		}
1804 		blknr = le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
1805 	}
1806 	/* Tripple indirect. */
1807 	else {
1808 		rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
1809 				      (blksz / 4 * blksz / 4));
1810 		perblock_child = blksz / 4;
1811 		perblock_parent = ((blksz / 4) * (blksz / 4));
1812 
1813 		if (ext4fs_indir1_block == NULL) {
1814 			ext4fs_indir1_block = zalloc(blksz);
1815 			if (ext4fs_indir1_block == NULL) {
1816 				printf("** TI ext2fs read block (indir 2 1)"
1817 					"malloc failed. **\n");
1818 				return -1;
1819 			}
1820 			ext4fs_indir1_size = blksz;
1821 			ext4fs_indir1_blkno = -1;
1822 		}
1823 		if (blksz != ext4fs_indir1_size) {
1824 			free(ext4fs_indir1_block);
1825 			ext4fs_indir1_block = NULL;
1826 			ext4fs_indir1_size = 0;
1827 			ext4fs_indir1_blkno = -1;
1828 			ext4fs_indir1_block = zalloc(blksz);
1829 			if (ext4fs_indir1_block == NULL) {
1830 				printf("** TI ext2fs read block (indir 2 1)"
1831 					"malloc failed. **\n");
1832 				return -1;
1833 			}
1834 			ext4fs_indir1_size = blksz;
1835 		}
1836 		if ((le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1837 		     log2_blksz) != ext4fs_indir1_blkno) {
1838 			status = ext4fs_devread
1839 			    ((lbaint_t)
1840 			     le32_to_cpu(inode->b.blocks.triple_indir_block)
1841 			     << log2_blksz, 0, blksz,
1842 			     (char *)ext4fs_indir1_block);
1843 			if (status == 0) {
1844 				printf("** TI ext2fs read block (indir 2 1)"
1845 					"failed. **\n");
1846 				return -1;
1847 			}
1848 			ext4fs_indir1_blkno =
1849 			    le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1850 			    log2_blksz;
1851 		}
1852 
1853 		if (ext4fs_indir2_block == NULL) {
1854 			ext4fs_indir2_block = zalloc(blksz);
1855 			if (ext4fs_indir2_block == NULL) {
1856 				printf("** TI ext2fs read block (indir 2 2)"
1857 					"malloc failed. **\n");
1858 				return -1;
1859 			}
1860 			ext4fs_indir2_size = blksz;
1861 			ext4fs_indir2_blkno = -1;
1862 		}
1863 		if (blksz != ext4fs_indir2_size) {
1864 			free(ext4fs_indir2_block);
1865 			ext4fs_indir2_block = NULL;
1866 			ext4fs_indir2_size = 0;
1867 			ext4fs_indir2_blkno = -1;
1868 			ext4fs_indir2_block = zalloc(blksz);
1869 			if (ext4fs_indir2_block == NULL) {
1870 				printf("** TI ext2fs read block (indir 2 2)"
1871 					"malloc failed. **\n");
1872 				return -1;
1873 			}
1874 			ext4fs_indir2_size = blksz;
1875 		}
1876 		if ((le32_to_cpu(ext4fs_indir1_block[rblock /
1877 						       perblock_parent]) <<
1878 		     log2_blksz)
1879 		    != ext4fs_indir2_blkno) {
1880 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1881 						(ext4fs_indir1_block
1882 						 [rblock /
1883 						  perblock_parent]) <<
1884 						log2_blksz, 0, blksz,
1885 						(char *)ext4fs_indir2_block);
1886 			if (status == 0) {
1887 				printf("** TI ext2fs read block (indir 2 2)"
1888 					"failed. **\n");
1889 				return -1;
1890 			}
1891 			ext4fs_indir2_blkno =
1892 			    le32_to_cpu(ext4fs_indir1_block[rblock /
1893 							      perblock_parent])
1894 			    << log2_blksz;
1895 		}
1896 
1897 		if (ext4fs_indir3_block == NULL) {
1898 			ext4fs_indir3_block = zalloc(blksz);
1899 			if (ext4fs_indir3_block == NULL) {
1900 				printf("** TI ext2fs read block (indir 2 2)"
1901 					"malloc failed. **\n");
1902 				return -1;
1903 			}
1904 			ext4fs_indir3_size = blksz;
1905 			ext4fs_indir3_blkno = -1;
1906 		}
1907 		if (blksz != ext4fs_indir3_size) {
1908 			free(ext4fs_indir3_block);
1909 			ext4fs_indir3_block = NULL;
1910 			ext4fs_indir3_size = 0;
1911 			ext4fs_indir3_blkno = -1;
1912 			ext4fs_indir3_block = zalloc(blksz);
1913 			if (ext4fs_indir3_block == NULL) {
1914 				printf("** TI ext2fs read block (indir 2 2)"
1915 					"malloc failed. **\n");
1916 				return -1;
1917 			}
1918 			ext4fs_indir3_size = blksz;
1919 		}
1920 		if ((le32_to_cpu(ext4fs_indir2_block[rblock
1921 						       /
1922 						       perblock_child]) <<
1923 		     log2_blksz) != ext4fs_indir3_blkno) {
1924 			status =
1925 			    ext4fs_devread((lbaint_t)le32_to_cpu
1926 					   (ext4fs_indir2_block
1927 					    [(rblock / perblock_child)
1928 					     % (blksz / 4)]) << log2_blksz, 0,
1929 					   blksz, (char *)ext4fs_indir3_block);
1930 			if (status == 0) {
1931 				printf("** TI ext2fs read block (indir 2 2)"
1932 				       "failed. **\n");
1933 				return -1;
1934 			}
1935 			ext4fs_indir3_blkno =
1936 			    le32_to_cpu(ext4fs_indir2_block[(rblock /
1937 							       perblock_child) %
1938 							      (blksz /
1939 							       4)]) <<
1940 			    log2_blksz;
1941 		}
1942 
1943 		blknr = le32_to_cpu(ext4fs_indir3_block
1944 				      [rblock % perblock_child]);
1945 	}
1946 	debug("read_allocated_block %ld\n", blknr);
1947 
1948 	return blknr;
1949 }
1950 
1951 /**
1952  * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's
1953  *			    global pointers
1954  *
1955  * This function assures that for a file with the same name but different size
1956  * the sequential store on the ext4 filesystem will be correct.
1957  *
1958  * In this function the global data, responsible for internal representation
1959  * of the ext4 data are initialized to the reset state. Without this, during
1960  * replacement of the smaller file with the bigger truncation of new file was
1961  * performed.
1962  */
1963 void ext4fs_reinit_global(void)
1964 {
1965 	if (ext4fs_indir1_block != NULL) {
1966 		free(ext4fs_indir1_block);
1967 		ext4fs_indir1_block = NULL;
1968 		ext4fs_indir1_size = 0;
1969 		ext4fs_indir1_blkno = -1;
1970 	}
1971 	if (ext4fs_indir2_block != NULL) {
1972 		free(ext4fs_indir2_block);
1973 		ext4fs_indir2_block = NULL;
1974 		ext4fs_indir2_size = 0;
1975 		ext4fs_indir2_blkno = -1;
1976 	}
1977 	if (ext4fs_indir3_block != NULL) {
1978 		free(ext4fs_indir3_block);
1979 		ext4fs_indir3_block = NULL;
1980 		ext4fs_indir3_size = 0;
1981 		ext4fs_indir3_blkno = -1;
1982 	}
1983 }
1984 void ext4fs_close(void)
1985 {
1986 	if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
1987 		ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
1988 		ext4fs_file = NULL;
1989 	}
1990 	if (ext4fs_root != NULL) {
1991 		free(ext4fs_root);
1992 		ext4fs_root = NULL;
1993 	}
1994 
1995 	ext4fs_reinit_global();
1996 }
1997 
1998 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
1999 				struct ext2fs_node **fnode, int *ftype)
2000 {
2001 	unsigned int fpos = 0;
2002 	int status;
2003 	loff_t actread;
2004 	struct ext2fs_node *diro = (struct ext2fs_node *) dir;
2005 
2006 #ifdef DEBUG
2007 	if (name != NULL)
2008 		printf("Iterate dir %s\n", name);
2009 #endif /* of DEBUG */
2010 	if (!diro->inode_read) {
2011 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2012 		if (status == 0)
2013 			return 0;
2014 	}
2015 	/* Search the file.  */
2016 	while (fpos < le32_to_cpu(diro->inode.size)) {
2017 		struct ext2_dirent dirent;
2018 
2019 		status = ext4fs_read_file(diro, fpos,
2020 					   sizeof(struct ext2_dirent),
2021 					   (char *)&dirent, &actread);
2022 		if (status < 0)
2023 			return 0;
2024 
2025 		if (dirent.direntlen == 0) {
2026 			printf("Failed to iterate over directory %s\n", name);
2027 			return 0;
2028 		}
2029 
2030 		if (dirent.namelen != 0) {
2031 			char filename[dirent.namelen + 1];
2032 			struct ext2fs_node *fdiro;
2033 			int type = FILETYPE_UNKNOWN;
2034 
2035 			status = ext4fs_read_file(diro,
2036 						  fpos +
2037 						  sizeof(struct ext2_dirent),
2038 						  dirent.namelen, filename,
2039 						  &actread);
2040 			if (status < 0)
2041 				return 0;
2042 
2043 			fdiro = zalloc(sizeof(struct ext2fs_node));
2044 			if (!fdiro)
2045 				return 0;
2046 
2047 			fdiro->data = diro->data;
2048 			fdiro->ino = le32_to_cpu(dirent.inode);
2049 
2050 			filename[dirent.namelen] = '\0';
2051 
2052 			if (dirent.filetype != FILETYPE_UNKNOWN) {
2053 				fdiro->inode_read = 0;
2054 
2055 				if (dirent.filetype == FILETYPE_DIRECTORY)
2056 					type = FILETYPE_DIRECTORY;
2057 				else if (dirent.filetype == FILETYPE_SYMLINK)
2058 					type = FILETYPE_SYMLINK;
2059 				else if (dirent.filetype == FILETYPE_REG)
2060 					type = FILETYPE_REG;
2061 			} else {
2062 				status = ext4fs_read_inode(diro->data,
2063 							   le32_to_cpu
2064 							   (dirent.inode),
2065 							   &fdiro->inode);
2066 				if (status == 0) {
2067 					free(fdiro);
2068 					return 0;
2069 				}
2070 				fdiro->inode_read = 1;
2071 
2072 				if ((le16_to_cpu(fdiro->inode.mode) &
2073 				     FILETYPE_INO_MASK) ==
2074 				    FILETYPE_INO_DIRECTORY) {
2075 					type = FILETYPE_DIRECTORY;
2076 				} else if ((le16_to_cpu(fdiro->inode.mode)
2077 					    & FILETYPE_INO_MASK) ==
2078 					   FILETYPE_INO_SYMLINK) {
2079 					type = FILETYPE_SYMLINK;
2080 				} else if ((le16_to_cpu(fdiro->inode.mode)
2081 					    & FILETYPE_INO_MASK) ==
2082 					   FILETYPE_INO_REG) {
2083 					type = FILETYPE_REG;
2084 				}
2085 			}
2086 #ifdef DEBUG
2087 			printf("iterate >%s<\n", filename);
2088 #endif /* of DEBUG */
2089 			if ((name != NULL) && (fnode != NULL)
2090 			    && (ftype != NULL)) {
2091 				if (strcmp(filename, name) == 0) {
2092 					*ftype = type;
2093 					*fnode = fdiro;
2094 					return 1;
2095 				}
2096 			} else {
2097 				if (fdiro->inode_read == 0) {
2098 					status = ext4fs_read_inode(diro->data,
2099 								 le32_to_cpu(
2100 								 dirent.inode),
2101 								 &fdiro->inode);
2102 					if (status == 0) {
2103 						free(fdiro);
2104 						return 0;
2105 					}
2106 					fdiro->inode_read = 1;
2107 				}
2108 				switch (type) {
2109 				case FILETYPE_DIRECTORY:
2110 					printf("<DIR> ");
2111 					break;
2112 				case FILETYPE_SYMLINK:
2113 					printf("<SYM> ");
2114 					break;
2115 				case FILETYPE_REG:
2116 					printf("      ");
2117 					break;
2118 				default:
2119 					printf("< ? > ");
2120 					break;
2121 				}
2122 				printf("%10u %s\n",
2123 				       le32_to_cpu(fdiro->inode.size),
2124 					filename);
2125 			}
2126 			free(fdiro);
2127 		}
2128 		fpos += le16_to_cpu(dirent.direntlen);
2129 	}
2130 	return 0;
2131 }
2132 
2133 static char *ext4fs_read_symlink(struct ext2fs_node *node)
2134 {
2135 	char *symlink;
2136 	struct ext2fs_node *diro = node;
2137 	int status;
2138 	loff_t actread;
2139 
2140 	if (!diro->inode_read) {
2141 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2142 		if (status == 0)
2143 			return NULL;
2144 	}
2145 	symlink = zalloc(le32_to_cpu(diro->inode.size) + 1);
2146 	if (!symlink)
2147 		return NULL;
2148 
2149 	if (le32_to_cpu(diro->inode.size) < sizeof(diro->inode.b.symlink)) {
2150 		strncpy(symlink, diro->inode.b.symlink,
2151 			 le32_to_cpu(diro->inode.size));
2152 	} else {
2153 		status = ext4fs_read_file(diro, 0,
2154 					   le32_to_cpu(diro->inode.size),
2155 					   symlink, &actread);
2156 		if ((status < 0) || (actread == 0)) {
2157 			free(symlink);
2158 			return NULL;
2159 		}
2160 	}
2161 	symlink[le32_to_cpu(diro->inode.size)] = '\0';
2162 	return symlink;
2163 }
2164 
2165 static int ext4fs_find_file1(const char *currpath,
2166 			     struct ext2fs_node *currroot,
2167 			     struct ext2fs_node **currfound, int *foundtype)
2168 {
2169 	char fpath[strlen(currpath) + 1];
2170 	char *name = fpath;
2171 	char *next;
2172 	int status;
2173 	int type = FILETYPE_DIRECTORY;
2174 	struct ext2fs_node *currnode = currroot;
2175 	struct ext2fs_node *oldnode = currroot;
2176 
2177 	strncpy(fpath, currpath, strlen(currpath) + 1);
2178 
2179 	/* Remove all leading slashes. */
2180 	while (*name == '/')
2181 		name++;
2182 
2183 	if (!*name) {
2184 		*currfound = currnode;
2185 		return 1;
2186 	}
2187 
2188 	for (;;) {
2189 		int found;
2190 
2191 		/* Extract the actual part from the pathname. */
2192 		next = strchr(name, '/');
2193 		if (next) {
2194 			/* Remove all leading slashes. */
2195 			while (*next == '/')
2196 				*(next++) = '\0';
2197 		}
2198 
2199 		if (type != FILETYPE_DIRECTORY) {
2200 			ext4fs_free_node(currnode, currroot);
2201 			return 0;
2202 		}
2203 
2204 		oldnode = currnode;
2205 
2206 		/* Iterate over the directory. */
2207 		found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
2208 		if (found == 0)
2209 			return 0;
2210 
2211 		if (found == -1)
2212 			break;
2213 
2214 		/* Read in the symlink and follow it. */
2215 		if (type == FILETYPE_SYMLINK) {
2216 			char *symlink;
2217 
2218 			/* Test if the symlink does not loop. */
2219 			if (++symlinknest == 8) {
2220 				ext4fs_free_node(currnode, currroot);
2221 				ext4fs_free_node(oldnode, currroot);
2222 				return 0;
2223 			}
2224 
2225 			symlink = ext4fs_read_symlink(currnode);
2226 			ext4fs_free_node(currnode, currroot);
2227 
2228 			if (!symlink) {
2229 				ext4fs_free_node(oldnode, currroot);
2230 				return 0;
2231 			}
2232 
2233 			debug("Got symlink >%s<\n", symlink);
2234 
2235 			if (symlink[0] == '/') {
2236 				ext4fs_free_node(oldnode, currroot);
2237 				oldnode = &ext4fs_root->diropen;
2238 			}
2239 
2240 			/* Lookup the node the symlink points to. */
2241 			status = ext4fs_find_file1(symlink, oldnode,
2242 						    &currnode, &type);
2243 
2244 			free(symlink);
2245 
2246 			if (status == 0) {
2247 				ext4fs_free_node(oldnode, currroot);
2248 				return 0;
2249 			}
2250 		}
2251 
2252 		ext4fs_free_node(oldnode, currroot);
2253 
2254 		/* Found the node! */
2255 		if (!next || *next == '\0') {
2256 			*currfound = currnode;
2257 			*foundtype = type;
2258 			return 1;
2259 		}
2260 		name = next;
2261 	}
2262 	return -1;
2263 }
2264 
2265 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
2266 	struct ext2fs_node **foundnode, int expecttype)
2267 {
2268 	int status;
2269 	int foundtype = FILETYPE_DIRECTORY;
2270 
2271 	symlinknest = 0;
2272 	if (!path)
2273 		return 0;
2274 
2275 	status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
2276 	if (status == 0)
2277 		return 0;
2278 
2279 	/* Check if the node that was found was of the expected type. */
2280 	if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
2281 		return 0;
2282 	else if ((expecttype == FILETYPE_DIRECTORY)
2283 		   && (foundtype != expecttype))
2284 		return 0;
2285 
2286 	return 1;
2287 }
2288 
2289 int ext4fs_open(const char *filename, loff_t *len)
2290 {
2291 	struct ext2fs_node *fdiro = NULL;
2292 	int status;
2293 
2294 	if (ext4fs_root == NULL)
2295 		return -1;
2296 
2297 	ext4fs_file = NULL;
2298 	status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
2299 				  FILETYPE_REG);
2300 	if (status == 0)
2301 		goto fail;
2302 
2303 	if (!fdiro->inode_read) {
2304 		status = ext4fs_read_inode(fdiro->data, fdiro->ino,
2305 				&fdiro->inode);
2306 		if (status == 0)
2307 			goto fail;
2308 	}
2309 	*len = le32_to_cpu(fdiro->inode.size);
2310 	ext4fs_file = fdiro;
2311 
2312 	return 0;
2313 fail:
2314 	ext4fs_free_node(fdiro, &ext4fs_root->diropen);
2315 
2316 	return -1;
2317 }
2318 
2319 int ext4fs_mount(unsigned part_length)
2320 {
2321 	struct ext2_data *data;
2322 	int status;
2323 	struct ext_filesystem *fs = get_fs();
2324 	data = zalloc(SUPERBLOCK_SIZE);
2325 	if (!data)
2326 		return 0;
2327 
2328 	/* Read the superblock. */
2329 	status = ext4_read_superblock((char *)&data->sblock);
2330 
2331 	if (status == 0)
2332 		goto fail;
2333 
2334 	/* Make sure this is an ext2 filesystem. */
2335 	if (le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
2336 		goto fail;
2337 
2338 
2339 	if (le32_to_cpu(data->sblock.revision_level) == 0) {
2340 		fs->inodesz = 128;
2341 		fs->gdsize = 32;
2342 	} else {
2343 		debug("EXT4 features COMPAT: %08x INCOMPAT: %08x RO_COMPAT: %08x\n",
2344 		      __le32_to_cpu(data->sblock.feature_compatibility),
2345 		      __le32_to_cpu(data->sblock.feature_incompat),
2346 		      __le32_to_cpu(data->sblock.feature_ro_compat));
2347 
2348 		fs->inodesz = le16_to_cpu(data->sblock.inode_size);
2349 		fs->gdsize = le32_to_cpu(data->sblock.feature_incompat) &
2350 			EXT4_FEATURE_INCOMPAT_64BIT ?
2351 			le16_to_cpu(data->sblock.descriptor_size) : 32;
2352 	}
2353 
2354 	debug("EXT2 rev %d, inode_size %d, descriptor size %d\n",
2355 	      le32_to_cpu(data->sblock.revision_level),
2356 	      fs->inodesz, fs->gdsize);
2357 
2358 	data->diropen.data = data;
2359 	data->diropen.ino = 2;
2360 	data->diropen.inode_read = 1;
2361 	data->inode = &data->diropen.inode;
2362 
2363 	status = ext4fs_read_inode(data, 2, data->inode);
2364 	if (status == 0)
2365 		goto fail;
2366 
2367 	ext4fs_root = data;
2368 
2369 	return 1;
2370 fail:
2371 	printf("Failed to mount ext2 filesystem...\n");
2372 	free(data);
2373 	ext4fs_root = NULL;
2374 
2375 	return 0;
2376 }
2377