xref: /openbmc/u-boot/fs/ext4/ext4_common.c (revision 2399e401)
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 	}
436 
437 	return crc;
438 }
439 
440 static int check_void_in_dentry(struct ext2_dirent *dir, char *filename)
441 {
442 	int dentry_length;
443 	int sizeof_void_space;
444 	int new_entry_byte_reqd;
445 	short padding_factor = 0;
446 
447 	if (dir->namelen % 4 != 0)
448 		padding_factor = 4 - (dir->namelen % 4);
449 
450 	dentry_length = sizeof(struct ext2_dirent) +
451 			dir->namelen + padding_factor;
452 	sizeof_void_space = le16_to_cpu(dir->direntlen) - dentry_length;
453 	if (sizeof_void_space == 0)
454 		return 0;
455 
456 	padding_factor = 0;
457 	if (strlen(filename) % 4 != 0)
458 		padding_factor = 4 - (strlen(filename) % 4);
459 
460 	new_entry_byte_reqd = strlen(filename) +
461 	    sizeof(struct ext2_dirent) + padding_factor;
462 	if (sizeof_void_space >= new_entry_byte_reqd) {
463 		dir->direntlen = cpu_to_le16(dentry_length);
464 		return sizeof_void_space;
465 	}
466 
467 	return 0;
468 }
469 
470 int ext4fs_update_parent_dentry(char *filename, int file_type)
471 {
472 	unsigned int *zero_buffer = NULL;
473 	char *root_first_block_buffer = NULL;
474 	int blk_idx;
475 	long int first_block_no_of_root = 0;
476 	int totalbytes = 0;
477 	unsigned int new_entry_byte_reqd;
478 	int sizeof_void_space = 0;
479 	int templength = 0;
480 	int inodeno = -1;
481 	int status;
482 	struct ext_filesystem *fs = get_fs();
483 	/* directory entry */
484 	struct ext2_dirent *dir;
485 	char *temp_dir = NULL;
486 	uint32_t new_blk_no;
487 	uint32_t new_size;
488 	uint32_t new_blockcnt;
489 	uint32_t directory_blocks;
490 
491 	zero_buffer = zalloc(fs->blksz);
492 	if (!zero_buffer) {
493 		printf("No Memory\n");
494 		return -1;
495 	}
496 	root_first_block_buffer = zalloc(fs->blksz);
497 	if (!root_first_block_buffer) {
498 		free(zero_buffer);
499 		printf("No Memory\n");
500 		return -1;
501 	}
502 	new_entry_byte_reqd = ROUND(strlen(filename) +
503 				    sizeof(struct ext2_dirent), 4);
504 restart:
505 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
506 		LOG2_BLOCK_SIZE(ext4fs_root);
507 	blk_idx = directory_blocks - 1;
508 
509 restart_read:
510 	/* read the block no allocated to a file */
511 	first_block_no_of_root = read_allocated_block(g_parent_inode, blk_idx);
512 	if (first_block_no_of_root <= 0)
513 		goto fail;
514 
515 	status = ext4fs_devread((lbaint_t)first_block_no_of_root
516 				* fs->sect_perblk,
517 				0, fs->blksz, root_first_block_buffer);
518 	if (status == 0)
519 		goto fail;
520 
521 	if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
522 		goto fail;
523 	dir = (struct ext2_dirent *)root_first_block_buffer;
524 	totalbytes = 0;
525 
526 	while (le16_to_cpu(dir->direntlen) > 0) {
527 		unsigned short used_len = ROUND(dir->namelen +
528 		    sizeof(struct ext2_dirent), 4);
529 
530 		/* last entry of block */
531 		if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen)) {
532 
533 			/* check if new entry fits */
534 			if ((used_len + new_entry_byte_reqd) <=
535 			    le16_to_cpu(dir->direntlen)) {
536 				dir->direntlen = cpu_to_le16(used_len);
537 				break;
538 			} else {
539 				if (blk_idx > 0) {
540 					printf("Block full, trying previous\n");
541 					blk_idx--;
542 					goto restart_read;
543 				}
544 				printf("All blocks full: Allocate new\n");
545 
546 				if (le32_to_cpu(g_parent_inode->flags) &
547 						EXT4_EXTENTS_FL) {
548 					printf("Directory uses extents\n");
549 					goto fail;
550 				}
551 				if (directory_blocks >= INDIRECT_BLOCKS) {
552 					printf("Directory exceeds limit\n");
553 					goto fail;
554 				}
555 				new_blk_no = ext4fs_get_new_blk_no();
556 				if (new_blk_no == -1) {
557 					printf("no block left to assign\n");
558 					goto fail;
559 				}
560 				put_ext4((uint64_t)new_blk_no * fs->blksz, zero_buffer, fs->blksz);
561 				g_parent_inode->b.blocks.
562 					dir_blocks[directory_blocks] =
563 					cpu_to_le32(new_blk_no);
564 
565 				new_size = le32_to_cpu(g_parent_inode->size);
566 				new_size += fs->blksz;
567 				g_parent_inode->size = cpu_to_le32(new_size);
568 
569 				new_blockcnt = le32_to_cpu(g_parent_inode->blockcnt);
570 				new_blockcnt += fs->sect_perblk;
571 				g_parent_inode->blockcnt = cpu_to_le32(new_blockcnt);
572 
573 				if (ext4fs_put_metadata
574 				    (root_first_block_buffer,
575 				     first_block_no_of_root))
576 					goto fail;
577 				goto restart;
578 			}
579 		}
580 
581 		templength = le16_to_cpu(dir->direntlen);
582 		totalbytes = totalbytes + templength;
583 		sizeof_void_space = check_void_in_dentry(dir, filename);
584 		if (sizeof_void_space)
585 			break;
586 
587 		dir = (struct ext2_dirent *)((char *)dir + templength);
588 	}
589 
590 	/* make a pointer ready for creating next directory entry */
591 	templength = le16_to_cpu(dir->direntlen);
592 	totalbytes = totalbytes + templength;
593 	dir = (struct ext2_dirent *)((char *)dir + templength);
594 
595 	/* get the next available inode number */
596 	inodeno = ext4fs_get_new_inode_no();
597 	if (inodeno == -1) {
598 		printf("no inode left to assign\n");
599 		goto fail;
600 	}
601 	dir->inode = cpu_to_le32(inodeno);
602 	if (sizeof_void_space)
603 		dir->direntlen = cpu_to_le16(sizeof_void_space);
604 	else
605 		dir->direntlen = cpu_to_le16(fs->blksz - totalbytes);
606 
607 	dir->namelen = strlen(filename);
608 	dir->filetype = FILETYPE_REG;	/* regular file */
609 	temp_dir = (char *)dir;
610 	temp_dir = temp_dir + sizeof(struct ext2_dirent);
611 	memcpy(temp_dir, filename, strlen(filename));
612 
613 	/* update or write  the 1st block of root inode */
614 	if (ext4fs_put_metadata(root_first_block_buffer,
615 				first_block_no_of_root))
616 		goto fail;
617 
618 fail:
619 	free(zero_buffer);
620 	free(root_first_block_buffer);
621 
622 	return inodeno;
623 }
624 
625 static int search_dir(struct ext2_inode *parent_inode, char *dirname)
626 {
627 	int status;
628 	int inodeno = 0;
629 	int offset;
630 	int blk_idx;
631 	long int blknr;
632 	char *block_buffer = NULL;
633 	struct ext2_dirent *dir = NULL;
634 	struct ext_filesystem *fs = get_fs();
635 	uint32_t directory_blocks;
636 	char *direntname;
637 
638 	directory_blocks = le32_to_cpu(parent_inode->size) >>
639 		LOG2_BLOCK_SIZE(ext4fs_root);
640 
641 	block_buffer = zalloc(fs->blksz);
642 	if (!block_buffer)
643 		goto fail;
644 
645 	/* get the block no allocated to a file */
646 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
647 		blknr = read_allocated_block(parent_inode, blk_idx);
648 		if (blknr <= 0)
649 			goto fail;
650 
651 		/* read the directory block */
652 		status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk,
653 					0, fs->blksz, (char *)block_buffer);
654 		if (status == 0)
655 			goto fail;
656 
657 		offset = 0;
658 		do {
659 			dir = (struct ext2_dirent *)(block_buffer + offset);
660 			direntname = (char*)(dir) + sizeof(struct ext2_dirent);
661 
662 			int direntlen = le16_to_cpu(dir->direntlen);
663 			if (direntlen < sizeof(struct ext2_dirent))
664 				break;
665 
666 			if (dir->inode && (strlen(dirname) == dir->namelen) &&
667 			    (strncmp(dirname, direntname, dir->namelen) == 0)) {
668 				inodeno = le32_to_cpu(dir->inode);
669 				break;
670 			}
671 
672 			offset += direntlen;
673 
674 		} while (offset < fs->blksz);
675 
676 		if (inodeno > 0) {
677 			free(block_buffer);
678 			return inodeno;
679 		}
680 	}
681 
682 fail:
683 	free(block_buffer);
684 
685 	return -1;
686 }
687 
688 static int find_dir_depth(char *dirname)
689 {
690 	char *token = strtok(dirname, "/");
691 	int count = 0;
692 	while (token != NULL) {
693 		token = strtok(NULL, "/");
694 		count++;
695 	}
696 	return count + 1 + 1;
697 	/*
698 	 * for example  for string /home/temp
699 	 * depth=home(1)+temp(1)+1 extra for NULL;
700 	 * so count is 4;
701 	 */
702 }
703 
704 static int parse_path(char **arr, char *dirname)
705 {
706 	char *token = strtok(dirname, "/");
707 	int i = 0;
708 
709 	/* add root */
710 	arr[i] = zalloc(strlen("/") + 1);
711 	if (!arr[i])
712 		return -ENOMEM;
713 	memcpy(arr[i++], "/", strlen("/"));
714 
715 	/* add each path entry after root */
716 	while (token != NULL) {
717 		arr[i] = zalloc(strlen(token) + 1);
718 		if (!arr[i])
719 			return -ENOMEM;
720 		memcpy(arr[i++], token, strlen(token));
721 		token = strtok(NULL, "/");
722 	}
723 	arr[i] = NULL;
724 
725 	return 0;
726 }
727 
728 int ext4fs_iget(int inode_no, struct ext2_inode *inode)
729 {
730 	if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0)
731 		return -1;
732 
733 	return 0;
734 }
735 
736 /*
737  * Function: ext4fs_get_parent_inode_num
738  * Return Value: inode Number of the parent directory of  file/Directory to be
739  * created
740  * dirname : Input parmater, input path name of the file/directory to be created
741  * dname : Output parameter, to be filled with the name of the directory
742  * extracted from dirname
743  */
744 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags)
745 {
746 	int i;
747 	int depth = 0;
748 	int matched_inode_no;
749 	int result_inode_no = -1;
750 	char **ptr = NULL;
751 	char *depth_dirname = NULL;
752 	char *parse_dirname = NULL;
753 	struct ext2_inode *parent_inode = NULL;
754 	struct ext2_inode *first_inode = NULL;
755 	struct ext2_inode temp_inode;
756 
757 	if (*dirname != '/') {
758 		printf("Please supply Absolute path\n");
759 		return -1;
760 	}
761 
762 	/* TODO: input validation make equivalent to linux */
763 	depth_dirname = zalloc(strlen(dirname) + 1);
764 	if (!depth_dirname)
765 		return -ENOMEM;
766 
767 	memcpy(depth_dirname, dirname, strlen(dirname));
768 	depth = find_dir_depth(depth_dirname);
769 	parse_dirname = zalloc(strlen(dirname) + 1);
770 	if (!parse_dirname)
771 		goto fail;
772 	memcpy(parse_dirname, dirname, strlen(dirname));
773 
774 	/* allocate memory for each directory level */
775 	ptr = zalloc((depth) * sizeof(char *));
776 	if (!ptr)
777 		goto fail;
778 	if (parse_path(ptr, parse_dirname))
779 		goto fail;
780 	parent_inode = zalloc(sizeof(struct ext2_inode));
781 	if (!parent_inode)
782 		goto fail;
783 	first_inode = zalloc(sizeof(struct ext2_inode));
784 	if (!first_inode)
785 		goto fail;
786 	memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode));
787 	memcpy(first_inode, parent_inode, sizeof(struct ext2_inode));
788 	if (flags & F_FILE)
789 		result_inode_no = EXT2_ROOT_INO;
790 	for (i = 1; i < depth; i++) {
791 		matched_inode_no = search_dir(parent_inode, ptr[i]);
792 		if (matched_inode_no == -1) {
793 			if (ptr[i + 1] == NULL && i == 1) {
794 				result_inode_no = EXT2_ROOT_INO;
795 				goto end;
796 			} else {
797 				if (ptr[i + 1] == NULL)
798 					break;
799 				printf("Invalid path\n");
800 				result_inode_no = -1;
801 				goto fail;
802 			}
803 		} else {
804 			if (ptr[i + 1] != NULL) {
805 				memset(parent_inode, '\0',
806 				       sizeof(struct ext2_inode));
807 				if (ext4fs_iget(matched_inode_no,
808 						parent_inode)) {
809 					result_inode_no = -1;
810 					goto fail;
811 				}
812 				result_inode_no = matched_inode_no;
813 			} else {
814 				break;
815 			}
816 		}
817 	}
818 
819 end:
820 	if (i == 1)
821 		matched_inode_no = search_dir(first_inode, ptr[i]);
822 	else
823 		matched_inode_no = search_dir(parent_inode, ptr[i]);
824 
825 	if (matched_inode_no != -1) {
826 		ext4fs_iget(matched_inode_no, &temp_inode);
827 		if (le16_to_cpu(temp_inode.mode) & S_IFDIR) {
828 			printf("It is a Directory\n");
829 			result_inode_no = -1;
830 			goto fail;
831 		}
832 	}
833 
834 	if (strlen(ptr[i]) > 256) {
835 		result_inode_no = -1;
836 		goto fail;
837 	}
838 	memcpy(dname, ptr[i], strlen(ptr[i]));
839 
840 fail:
841 	free(depth_dirname);
842 	free(parse_dirname);
843 	for (i = 0; i < depth; i++) {
844 		if (!ptr[i])
845 			break;
846 		free(ptr[i]);
847 	}
848 	free(ptr);
849 	free(parent_inode);
850 	free(first_inode);
851 
852 	return result_inode_no;
853 }
854 
855 static int unlink_filename(char *filename, unsigned int blknr)
856 {
857 	int status;
858 	int inodeno = 0;
859 	int offset;
860 	char *block_buffer = NULL;
861 	struct ext2_dirent *dir = NULL;
862 	struct ext2_dirent *previous_dir;
863 	struct ext_filesystem *fs = get_fs();
864 	int ret = -1;
865 	char *direntname;
866 
867 	block_buffer = zalloc(fs->blksz);
868 	if (!block_buffer)
869 		return -ENOMEM;
870 
871 	/* read the directory block */
872 	status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0,
873 				fs->blksz, block_buffer);
874 	if (status == 0)
875 		goto fail;
876 
877 	offset = 0;
878 	do {
879 		previous_dir = dir;
880 		dir = (struct ext2_dirent *)(block_buffer + offset);
881 		direntname = (char *)(dir) + sizeof(struct ext2_dirent);
882 
883 		int direntlen = le16_to_cpu(dir->direntlen);
884 		if (direntlen < sizeof(struct ext2_dirent))
885 			break;
886 
887 		if (dir->inode && (strlen(filename) == dir->namelen) &&
888 		    (strncmp(direntname, filename, dir->namelen) == 0)) {
889 			inodeno = le32_to_cpu(dir->inode);
890 			break;
891 		}
892 
893 		offset += direntlen;
894 
895 	} while (offset < fs->blksz);
896 
897 	if (inodeno > 0) {
898 		printf("file found, deleting\n");
899 		if (ext4fs_log_journal(block_buffer, blknr))
900 			goto fail;
901 
902 		if (previous_dir) {
903 			/* merge dir entry with predecessor */
904 			uint16_t new_len;
905 			new_len = le16_to_cpu(previous_dir->direntlen);
906 			new_len += le16_to_cpu(dir->direntlen);
907 			previous_dir->direntlen = cpu_to_le16(new_len);
908 		} else {
909 			/* invalidate dir entry */
910 			dir->inode = 0;
911 		}
912 		if (ext4fs_put_metadata(block_buffer, blknr))
913 			goto fail;
914 		ret = inodeno;
915 	}
916 fail:
917 	free(block_buffer);
918 
919 	return ret;
920 }
921 
922 int ext4fs_filename_unlink(char *filename)
923 {
924 	int blk_idx;
925 	long int blknr = -1;
926 	int inodeno = -1;
927 	uint32_t directory_blocks;
928 
929 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
930 		LOG2_BLOCK_SIZE(ext4fs_root);
931 
932 	/* read the block no allocated to a file */
933 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
934 		blknr = read_allocated_block(g_parent_inode, blk_idx);
935 		if (blknr <= 0)
936 			break;
937 		inodeno = unlink_filename(filename, blknr);
938 		if (inodeno != -1)
939 			return inodeno;
940 	}
941 
942 	return -1;
943 }
944 
945 uint32_t ext4fs_get_new_blk_no(void)
946 {
947 	short i;
948 	short status;
949 	int remainder;
950 	unsigned int bg_idx;
951 	static int prev_bg_bitmap_index = -1;
952 	unsigned int blk_per_grp = le32_to_cpu(ext4fs_root->sblock.blocks_per_group);
953 	struct ext_filesystem *fs = get_fs();
954 	char *journal_buffer = zalloc(fs->blksz);
955 	char *zero_buffer = zalloc(fs->blksz);
956 	if (!journal_buffer || !zero_buffer)
957 		goto fail;
958 
959 	if (fs->first_pass_bbmap == 0) {
960 		for (i = 0; i < fs->no_blkgrp; i++) {
961 			struct ext2_block_group *bgd = NULL;
962 			bgd = ext4fs_get_group_descriptor(fs, i);
963 			if (ext4fs_bg_get_free_blocks(bgd, fs)) {
964 				uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
965 				uint64_t b_bitmap_blk =
966 					ext4fs_bg_get_block_id(bgd, fs);
967 				if (bg_flags & EXT4_BG_BLOCK_UNINIT) {
968 					memcpy(fs->blk_bmaps[i], zero_buffer,
969 					       fs->blksz);
970 					put_ext4(b_bitmap_blk * fs->blksz,
971 						 fs->blk_bmaps[i], fs->blksz);
972 					bg_flags &= ~EXT4_BG_BLOCK_UNINIT;
973 					ext4fs_bg_set_flags(bgd, bg_flags);
974 				}
975 				fs->curr_blkno =
976 				    _get_new_blk_no(fs->blk_bmaps[i]);
977 				if (fs->curr_blkno == -1)
978 					/* block bitmap is completely filled */
979 					continue;
980 				fs->curr_blkno = fs->curr_blkno +
981 						(i * fs->blksz * 8);
982 				fs->first_pass_bbmap++;
983 				ext4fs_bg_free_blocks_dec(bgd, fs);
984 				ext4fs_sb_free_blocks_dec(fs->sb);
985 				status = ext4fs_devread(b_bitmap_blk *
986 							fs->sect_perblk,
987 							0, fs->blksz,
988 							journal_buffer);
989 				if (status == 0)
990 					goto fail;
991 				if (ext4fs_log_journal(journal_buffer,
992 						       b_bitmap_blk))
993 					goto fail;
994 				goto success;
995 			} else {
996 				debug("no space left on block group %d\n", i);
997 			}
998 		}
999 
1000 		goto fail;
1001 	} else {
1002 		fs->curr_blkno++;
1003 restart:
1004 		/* get the blockbitmap index respective to blockno */
1005 		bg_idx = fs->curr_blkno / blk_per_grp;
1006 		if (fs->blksz == 1024) {
1007 			remainder = fs->curr_blkno % blk_per_grp;
1008 			if (!remainder)
1009 				bg_idx--;
1010 		}
1011 
1012 		/*
1013 		 * To skip completely filled block group bitmaps
1014 		 * Optimize the block allocation
1015 		 */
1016 		if (bg_idx >= fs->no_blkgrp)
1017 			goto fail;
1018 
1019 		struct ext2_block_group *bgd = NULL;
1020 		bgd = ext4fs_get_group_descriptor(fs, bg_idx);
1021 		if (ext4fs_bg_get_free_blocks(bgd, fs) == 0) {
1022 			debug("block group %u is full. Skipping\n", bg_idx);
1023 			fs->curr_blkno = (bg_idx + 1) * blk_per_grp;
1024 			if (fs->blksz == 1024)
1025 				fs->curr_blkno += 1;
1026 			goto restart;
1027 		}
1028 
1029 		uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1030 		uint64_t b_bitmap_blk = ext4fs_bg_get_block_id(bgd, fs);
1031 		if (bg_flags & EXT4_BG_BLOCK_UNINIT) {
1032 			memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz);
1033 			put_ext4(b_bitmap_blk * fs->blksz,
1034 				 zero_buffer, fs->blksz);
1035 			bg_flags &= ~EXT4_BG_BLOCK_UNINIT;
1036 			ext4fs_bg_set_flags(bgd, bg_flags);
1037 		}
1038 
1039 		if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx],
1040 				   bg_idx) != 0) {
1041 			debug("going for restart for the block no %ld %u\n",
1042 			      fs->curr_blkno, bg_idx);
1043 			fs->curr_blkno++;
1044 			goto restart;
1045 		}
1046 
1047 		/* journal backup */
1048 		if (prev_bg_bitmap_index != bg_idx) {
1049 			status = ext4fs_devread(b_bitmap_blk * fs->sect_perblk,
1050 						0, fs->blksz, journal_buffer);
1051 			if (status == 0)
1052 				goto fail;
1053 			if (ext4fs_log_journal(journal_buffer, b_bitmap_blk))
1054 				goto fail;
1055 
1056 			prev_bg_bitmap_index = bg_idx;
1057 		}
1058 		ext4fs_bg_free_blocks_dec(bgd, fs);
1059 		ext4fs_sb_free_blocks_dec(fs->sb);
1060 		goto success;
1061 	}
1062 success:
1063 	free(journal_buffer);
1064 	free(zero_buffer);
1065 
1066 	return fs->curr_blkno;
1067 fail:
1068 	free(journal_buffer);
1069 	free(zero_buffer);
1070 
1071 	return -1;
1072 }
1073 
1074 int ext4fs_get_new_inode_no(void)
1075 {
1076 	short i;
1077 	short status;
1078 	unsigned int ibmap_idx;
1079 	static int prev_inode_bitmap_index = -1;
1080 	unsigned int inodes_per_grp = le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
1081 	struct ext_filesystem *fs = get_fs();
1082 	char *journal_buffer = zalloc(fs->blksz);
1083 	char *zero_buffer = zalloc(fs->blksz);
1084 	if (!journal_buffer || !zero_buffer)
1085 		goto fail;
1086 	int has_gdt_chksum = le32_to_cpu(fs->sb->feature_ro_compat) &
1087 		EXT4_FEATURE_RO_COMPAT_GDT_CSUM ? 1 : 0;
1088 
1089 	if (fs->first_pass_ibmap == 0) {
1090 		for (i = 0; i < fs->no_blkgrp; i++) {
1091 			uint32_t free_inodes;
1092 			struct ext2_block_group *bgd = NULL;
1093 			bgd = ext4fs_get_group_descriptor(fs, i);
1094 			free_inodes = ext4fs_bg_get_free_inodes(bgd, fs);
1095 			if (free_inodes) {
1096 				uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1097 				uint64_t i_bitmap_blk =
1098 					ext4fs_bg_get_inode_id(bgd, fs);
1099 				if (has_gdt_chksum)
1100 					bgd->bg_itable_unused = free_inodes;
1101 				if (bg_flags & EXT4_BG_INODE_UNINIT) {
1102 					put_ext4(i_bitmap_blk * fs->blksz,
1103 						 zero_buffer, fs->blksz);
1104 					bg_flags &= ~EXT4_BG_INODE_UNINIT;
1105 					ext4fs_bg_set_flags(bgd, bg_flags);
1106 					memcpy(fs->inode_bmaps[i],
1107 					       zero_buffer, fs->blksz);
1108 				}
1109 				fs->curr_inode_no =
1110 				    _get_new_inode_no(fs->inode_bmaps[i]);
1111 				if (fs->curr_inode_no == -1)
1112 					/* inode bitmap is completely filled */
1113 					continue;
1114 				fs->curr_inode_no = fs->curr_inode_no +
1115 							(i * inodes_per_grp);
1116 				fs->first_pass_ibmap++;
1117 				ext4fs_bg_free_inodes_dec(bgd, fs);
1118 				if (has_gdt_chksum)
1119 					ext4fs_bg_itable_unused_dec(bgd, fs);
1120 				ext4fs_sb_free_inodes_dec(fs->sb);
1121 				status = ext4fs_devread(i_bitmap_blk *
1122 							fs->sect_perblk,
1123 							0, fs->blksz,
1124 							journal_buffer);
1125 				if (status == 0)
1126 					goto fail;
1127 				if (ext4fs_log_journal(journal_buffer,
1128 						       i_bitmap_blk))
1129 					goto fail;
1130 				goto success;
1131 			} else
1132 				debug("no inode left on block group %d\n", i);
1133 		}
1134 		goto fail;
1135 	} else {
1136 restart:
1137 		fs->curr_inode_no++;
1138 		/* get the blockbitmap index respective to blockno */
1139 		ibmap_idx = fs->curr_inode_no / inodes_per_grp;
1140 		struct ext2_block_group *bgd =
1141 			ext4fs_get_group_descriptor(fs, ibmap_idx);
1142 		uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1143 		uint64_t i_bitmap_blk = ext4fs_bg_get_inode_id(bgd, fs);
1144 
1145 		if (bg_flags & EXT4_BG_INODE_UNINIT) {
1146 			put_ext4(i_bitmap_blk * fs->blksz,
1147 				 zero_buffer, fs->blksz);
1148 			bg_flags &= ~EXT4_BG_INODE_UNINIT;
1149 			ext4fs_bg_set_flags(bgd, bg_flags);
1150 			memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer,
1151 				fs->blksz);
1152 		}
1153 
1154 		if (ext4fs_set_inode_bmap(fs->curr_inode_no,
1155 					  fs->inode_bmaps[ibmap_idx],
1156 					  ibmap_idx) != 0) {
1157 			debug("going for restart for the block no %d %u\n",
1158 			      fs->curr_inode_no, ibmap_idx);
1159 			goto restart;
1160 		}
1161 
1162 		/* journal backup */
1163 		if (prev_inode_bitmap_index != ibmap_idx) {
1164 			status = ext4fs_devread(i_bitmap_blk * fs->sect_perblk,
1165 						0, fs->blksz, journal_buffer);
1166 			if (status == 0)
1167 				goto fail;
1168 			if (ext4fs_log_journal(journal_buffer,
1169 						le32_to_cpu(bgd->inode_id)))
1170 				goto fail;
1171 			prev_inode_bitmap_index = ibmap_idx;
1172 		}
1173 		ext4fs_bg_free_inodes_dec(bgd, fs);
1174 		if (has_gdt_chksum)
1175 			bgd->bg_itable_unused = bgd->free_inodes;
1176 		ext4fs_sb_free_inodes_dec(fs->sb);
1177 		goto success;
1178 	}
1179 
1180 success:
1181 	free(journal_buffer);
1182 	free(zero_buffer);
1183 
1184 	return fs->curr_inode_no;
1185 fail:
1186 	free(journal_buffer);
1187 	free(zero_buffer);
1188 
1189 	return -1;
1190 
1191 }
1192 
1193 
1194 static void alloc_single_indirect_block(struct ext2_inode *file_inode,
1195 					unsigned int *total_remaining_blocks,
1196 					unsigned int *no_blks_reqd)
1197 {
1198 	short i;
1199 	short status;
1200 	long int actual_block_no;
1201 	long int si_blockno;
1202 	/* si :single indirect */
1203 	__le32 *si_buffer = NULL;
1204 	__le32 *si_start_addr = NULL;
1205 	struct ext_filesystem *fs = get_fs();
1206 
1207 	if (*total_remaining_blocks != 0) {
1208 		si_buffer = zalloc(fs->blksz);
1209 		if (!si_buffer) {
1210 			printf("No Memory\n");
1211 			return;
1212 		}
1213 		si_start_addr = si_buffer;
1214 		si_blockno = ext4fs_get_new_blk_no();
1215 		if (si_blockno == -1) {
1216 			printf("no block left to assign\n");
1217 			goto fail;
1218 		}
1219 		(*no_blks_reqd)++;
1220 		debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks);
1221 
1222 		status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk,
1223 					0, fs->blksz, (char *)si_buffer);
1224 		memset(si_buffer, '\0', fs->blksz);
1225 		if (status == 0)
1226 			goto fail;
1227 
1228 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1229 			actual_block_no = ext4fs_get_new_blk_no();
1230 			if (actual_block_no == -1) {
1231 				printf("no block left to assign\n");
1232 				goto fail;
1233 			}
1234 			*si_buffer = cpu_to_le32(actual_block_no);
1235 			debug("SIAB %u: %u\n", *si_buffer,
1236 				*total_remaining_blocks);
1237 
1238 			si_buffer++;
1239 			(*total_remaining_blocks)--;
1240 			if (*total_remaining_blocks == 0)
1241 				break;
1242 		}
1243 
1244 		/* write the block to disk */
1245 		put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)),
1246 			 si_start_addr, fs->blksz);
1247 		file_inode->b.blocks.indir_block = cpu_to_le32(si_blockno);
1248 	}
1249 fail:
1250 	free(si_start_addr);
1251 }
1252 
1253 static void alloc_double_indirect_block(struct ext2_inode *file_inode,
1254 					unsigned int *total_remaining_blocks,
1255 					unsigned int *no_blks_reqd)
1256 {
1257 	short i;
1258 	short j;
1259 	short status;
1260 	long int actual_block_no;
1261 	/* di:double indirect */
1262 	long int di_blockno_parent;
1263 	long int di_blockno_child;
1264 	__le32 *di_parent_buffer = NULL;
1265 	__le32 *di_child_buff = NULL;
1266 	__le32 *di_block_start_addr = NULL;
1267 	__le32 *di_child_buff_start = NULL;
1268 	struct ext_filesystem *fs = get_fs();
1269 
1270 	if (*total_remaining_blocks != 0) {
1271 		/* double indirect parent block connecting to inode */
1272 		di_blockno_parent = ext4fs_get_new_blk_no();
1273 		if (di_blockno_parent == -1) {
1274 			printf("no block left to assign\n");
1275 			goto fail;
1276 		}
1277 		di_parent_buffer = zalloc(fs->blksz);
1278 		if (!di_parent_buffer)
1279 			goto fail;
1280 
1281 		di_block_start_addr = di_parent_buffer;
1282 		(*no_blks_reqd)++;
1283 		debug("DIPB %ld: %u\n", di_blockno_parent,
1284 		      *total_remaining_blocks);
1285 
1286 		status = ext4fs_devread((lbaint_t)di_blockno_parent *
1287 					fs->sect_perblk, 0,
1288 					fs->blksz, (char *)di_parent_buffer);
1289 
1290 		if (!status) {
1291 			printf("%s: Device read error!\n", __func__);
1292 			goto fail;
1293 		}
1294 		memset(di_parent_buffer, '\0', fs->blksz);
1295 
1296 		/*
1297 		 * start:for each double indirect parent
1298 		 * block create one more block
1299 		 */
1300 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1301 			di_blockno_child = ext4fs_get_new_blk_no();
1302 			if (di_blockno_child == -1) {
1303 				printf("no block left to assign\n");
1304 				goto fail;
1305 			}
1306 			di_child_buff = zalloc(fs->blksz);
1307 			if (!di_child_buff)
1308 				goto fail;
1309 
1310 			di_child_buff_start = di_child_buff;
1311 			*di_parent_buffer = cpu_to_le32(di_blockno_child);
1312 			di_parent_buffer++;
1313 			(*no_blks_reqd)++;
1314 			debug("DICB %ld: %u\n", di_blockno_child,
1315 			      *total_remaining_blocks);
1316 
1317 			status = ext4fs_devread((lbaint_t)di_blockno_child *
1318 						fs->sect_perblk, 0,
1319 						fs->blksz,
1320 						(char *)di_child_buff);
1321 
1322 			if (!status) {
1323 				printf("%s: Device read error!\n", __func__);
1324 				goto fail;
1325 			}
1326 			memset(di_child_buff, '\0', fs->blksz);
1327 			/* filling of actual datablocks for each child */
1328 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1329 				actual_block_no = ext4fs_get_new_blk_no();
1330 				if (actual_block_no == -1) {
1331 					printf("no block left to assign\n");
1332 					goto fail;
1333 				}
1334 				*di_child_buff = cpu_to_le32(actual_block_no);
1335 				debug("DIAB %ld: %u\n", actual_block_no,
1336 				      *total_remaining_blocks);
1337 
1338 				di_child_buff++;
1339 				(*total_remaining_blocks)--;
1340 				if (*total_remaining_blocks == 0)
1341 					break;
1342 			}
1343 			/* write the block  table */
1344 			put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)),
1345 				 di_child_buff_start, fs->blksz);
1346 			free(di_child_buff_start);
1347 			di_child_buff_start = NULL;
1348 
1349 			if (*total_remaining_blocks == 0)
1350 				break;
1351 		}
1352 		put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)),
1353 			 di_block_start_addr, fs->blksz);
1354 		file_inode->b.blocks.double_indir_block = cpu_to_le32(di_blockno_parent);
1355 	}
1356 fail:
1357 	free(di_block_start_addr);
1358 }
1359 
1360 static void alloc_triple_indirect_block(struct ext2_inode *file_inode,
1361 					unsigned int *total_remaining_blocks,
1362 					unsigned int *no_blks_reqd)
1363 {
1364 	short i;
1365 	short j;
1366 	short k;
1367 	long int actual_block_no;
1368 	/* ti: Triple Indirect */
1369 	long int ti_gp_blockno;
1370 	long int ti_parent_blockno;
1371 	long int ti_child_blockno;
1372 	__le32 *ti_gp_buff = NULL;
1373 	__le32 *ti_parent_buff = NULL;
1374 	__le32 *ti_child_buff = NULL;
1375 	__le32 *ti_gp_buff_start_addr = NULL;
1376 	__le32 *ti_pbuff_start_addr = NULL;
1377 	__le32 *ti_cbuff_start_addr = NULL;
1378 	struct ext_filesystem *fs = get_fs();
1379 	if (*total_remaining_blocks != 0) {
1380 		/* triple indirect grand parent block connecting to inode */
1381 		ti_gp_blockno = ext4fs_get_new_blk_no();
1382 		if (ti_gp_blockno == -1) {
1383 			printf("no block left to assign\n");
1384 			return;
1385 		}
1386 		ti_gp_buff = zalloc(fs->blksz);
1387 		if (!ti_gp_buff)
1388 			return;
1389 
1390 		ti_gp_buff_start_addr = ti_gp_buff;
1391 		(*no_blks_reqd)++;
1392 		debug("TIGPB %ld: %u\n", ti_gp_blockno,
1393 		      *total_remaining_blocks);
1394 
1395 		/* for each 4 byte grand parent entry create one more block */
1396 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1397 			ti_parent_blockno = ext4fs_get_new_blk_no();
1398 			if (ti_parent_blockno == -1) {
1399 				printf("no block left to assign\n");
1400 				goto fail;
1401 			}
1402 			ti_parent_buff = zalloc(fs->blksz);
1403 			if (!ti_parent_buff)
1404 				goto fail;
1405 
1406 			ti_pbuff_start_addr = ti_parent_buff;
1407 			*ti_gp_buff = cpu_to_le32(ti_parent_blockno);
1408 			ti_gp_buff++;
1409 			(*no_blks_reqd)++;
1410 			debug("TIPB %ld: %u\n", ti_parent_blockno,
1411 			      *total_remaining_blocks);
1412 
1413 			/* for each 4 byte entry parent create one more block */
1414 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1415 				ti_child_blockno = ext4fs_get_new_blk_no();
1416 				if (ti_child_blockno == -1) {
1417 					printf("no block left assign\n");
1418 					goto fail1;
1419 				}
1420 				ti_child_buff = zalloc(fs->blksz);
1421 				if (!ti_child_buff)
1422 					goto fail1;
1423 
1424 				ti_cbuff_start_addr = ti_child_buff;
1425 				*ti_parent_buff = cpu_to_le32(ti_child_blockno);
1426 				ti_parent_buff++;
1427 				(*no_blks_reqd)++;
1428 				debug("TICB %ld: %u\n", ti_parent_blockno,
1429 				      *total_remaining_blocks);
1430 
1431 				/* fill actual datablocks for each child */
1432 				for (k = 0; k < (fs->blksz / sizeof(int));
1433 					k++) {
1434 					actual_block_no =
1435 					    ext4fs_get_new_blk_no();
1436 					if (actual_block_no == -1) {
1437 						printf("no block left\n");
1438 						free(ti_cbuff_start_addr);
1439 						goto fail1;
1440 					}
1441 					*ti_child_buff = cpu_to_le32(actual_block_no);
1442 					debug("TIAB %ld: %u\n", actual_block_no,
1443 					      *total_remaining_blocks);
1444 
1445 					ti_child_buff++;
1446 					(*total_remaining_blocks)--;
1447 					if (*total_remaining_blocks == 0)
1448 						break;
1449 				}
1450 				/* write the child block */
1451 				put_ext4(((uint64_t) ((uint64_t)ti_child_blockno *
1452 						      (uint64_t)fs->blksz)),
1453 					 ti_cbuff_start_addr, fs->blksz);
1454 				free(ti_cbuff_start_addr);
1455 
1456 				if (*total_remaining_blocks == 0)
1457 					break;
1458 			}
1459 			/* write the parent block */
1460 			put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)),
1461 				 ti_pbuff_start_addr, fs->blksz);
1462 			free(ti_pbuff_start_addr);
1463 
1464 			if (*total_remaining_blocks == 0)
1465 				break;
1466 		}
1467 		/* write the grand parent block */
1468 		put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)),
1469 			 ti_gp_buff_start_addr, fs->blksz);
1470 		file_inode->b.blocks.triple_indir_block = cpu_to_le32(ti_gp_blockno);
1471 		free(ti_gp_buff_start_addr);
1472 		return;
1473 	}
1474 fail1:
1475 	free(ti_pbuff_start_addr);
1476 fail:
1477 	free(ti_gp_buff_start_addr);
1478 }
1479 
1480 void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
1481 				unsigned int total_remaining_blocks,
1482 				unsigned int *total_no_of_block)
1483 {
1484 	short i;
1485 	long int direct_blockno;
1486 	unsigned int no_blks_reqd = 0;
1487 
1488 	/* allocation of direct blocks */
1489 	for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) {
1490 		direct_blockno = ext4fs_get_new_blk_no();
1491 		if (direct_blockno == -1) {
1492 			printf("no block left to assign\n");
1493 			return;
1494 		}
1495 		file_inode->b.blocks.dir_blocks[i] = cpu_to_le32(direct_blockno);
1496 		debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);
1497 
1498 		total_remaining_blocks--;
1499 	}
1500 
1501 	alloc_single_indirect_block(file_inode, &total_remaining_blocks,
1502 				    &no_blks_reqd);
1503 	alloc_double_indirect_block(file_inode, &total_remaining_blocks,
1504 				    &no_blks_reqd);
1505 	alloc_triple_indirect_block(file_inode, &total_remaining_blocks,
1506 				    &no_blks_reqd);
1507 	*total_no_of_block += no_blks_reqd;
1508 }
1509 
1510 #endif
1511 
1512 static struct ext4_extent_header *ext4fs_get_extent_block
1513 	(struct ext2_data *data, char *buf,
1514 		struct ext4_extent_header *ext_block,
1515 		uint32_t fileblock, int log2_blksz)
1516 {
1517 	struct ext4_extent_idx *index;
1518 	unsigned long long block;
1519 	int blksz = EXT2_BLOCK_SIZE(data);
1520 	int i;
1521 
1522 	while (1) {
1523 		index = (struct ext4_extent_idx *)(ext_block + 1);
1524 
1525 		if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
1526 			return NULL;
1527 
1528 		if (ext_block->eh_depth == 0)
1529 			return ext_block;
1530 		i = -1;
1531 		do {
1532 			i++;
1533 			if (i >= le16_to_cpu(ext_block->eh_entries))
1534 				break;
1535 		} while (fileblock >= le32_to_cpu(index[i].ei_block));
1536 
1537 		if (--i < 0)
1538 			return NULL;
1539 
1540 		block = le16_to_cpu(index[i].ei_leaf_hi);
1541 		block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
1542 
1543 		if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz,
1544 				   buf))
1545 			ext_block = (struct ext4_extent_header *)buf;
1546 		else
1547 			return NULL;
1548 	}
1549 }
1550 
1551 static int ext4fs_blockgroup
1552 	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
1553 {
1554 	long int blkno;
1555 	unsigned int blkoff, desc_per_blk;
1556 	int log2blksz = get_fs()->dev_desc->log2blksz;
1557 	int desc_size = get_fs()->gdsize;
1558 
1559 	desc_per_blk = EXT2_BLOCK_SIZE(data) / desc_size;
1560 
1561 	blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
1562 			group / desc_per_blk;
1563 	blkoff = (group % desc_per_blk) * desc_size;
1564 
1565 	debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
1566 	      group, blkno, blkoff);
1567 
1568 	return ext4fs_devread((lbaint_t)blkno <<
1569 			      (LOG2_BLOCK_SIZE(data) - log2blksz),
1570 			      blkoff, desc_size, (char *)blkgrp);
1571 }
1572 
1573 int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
1574 {
1575 	struct ext2_block_group blkgrp;
1576 	struct ext2_sblock *sblock = &data->sblock;
1577 	struct ext_filesystem *fs = get_fs();
1578 	int log2blksz = get_fs()->dev_desc->log2blksz;
1579 	int inodes_per_block, status;
1580 	long int blkno;
1581 	unsigned int blkoff;
1582 
1583 	/* It is easier to calculate if the first inode is 0. */
1584 	ino--;
1585 	status = ext4fs_blockgroup(data, ino / le32_to_cpu
1586 				   (sblock->inodes_per_group), &blkgrp);
1587 	if (status == 0)
1588 		return 0;
1589 
1590 	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
1591 	blkno = ext4fs_bg_get_inode_table_id(&blkgrp, fs) +
1592 	    (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1593 	blkoff = (ino % inodes_per_block) * fs->inodesz;
1594 	/* Read the inode. */
1595 	status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) -
1596 				log2blksz), blkoff,
1597 				sizeof(struct ext2_inode), (char *)inode);
1598 	if (status == 0)
1599 		return 0;
1600 
1601 	return 1;
1602 }
1603 
1604 long int read_allocated_block(struct ext2_inode *inode, int fileblock)
1605 {
1606 	long int blknr;
1607 	int blksz;
1608 	int log2_blksz;
1609 	int status;
1610 	long int rblock;
1611 	long int perblock_parent;
1612 	long int perblock_child;
1613 	unsigned long long start;
1614 	/* get the blocksize of the filesystem */
1615 	blksz = EXT2_BLOCK_SIZE(ext4fs_root);
1616 	log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
1617 		- get_fs()->dev_desc->log2blksz;
1618 
1619 	if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
1620 		long int startblock, endblock;
1621 		char *buf = zalloc(blksz);
1622 		if (!buf)
1623 			return -ENOMEM;
1624 		struct ext4_extent_header *ext_block;
1625 		struct ext4_extent *extent;
1626 		int i;
1627 		ext_block =
1628 			ext4fs_get_extent_block(ext4fs_root, buf,
1629 						(struct ext4_extent_header *)
1630 						inode->b.blocks.dir_blocks,
1631 						fileblock, log2_blksz);
1632 		if (!ext_block) {
1633 			printf("invalid extent block\n");
1634 			free(buf);
1635 			return -EINVAL;
1636 		}
1637 
1638 		extent = (struct ext4_extent *)(ext_block + 1);
1639 
1640 		for (i = 0; i < le16_to_cpu(ext_block->eh_entries); i++) {
1641 			startblock = le32_to_cpu(extent[i].ee_block);
1642 			endblock = startblock + le16_to_cpu(extent[i].ee_len);
1643 
1644 			if (startblock > fileblock) {
1645 				/* Sparse file */
1646 				free(buf);
1647 				return 0;
1648 
1649 			} else if (fileblock < endblock) {
1650 				start = le16_to_cpu(extent[i].ee_start_hi);
1651 				start = (start << 32) +
1652 					le32_to_cpu(extent[i].ee_start_lo);
1653 				free(buf);
1654 				return (fileblock - startblock) + start;
1655 			}
1656 		}
1657 
1658 		free(buf);
1659 		return 0;
1660 	}
1661 
1662 	/* Direct blocks. */
1663 	if (fileblock < INDIRECT_BLOCKS)
1664 		blknr = le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
1665 
1666 	/* Indirect. */
1667 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
1668 		if (ext4fs_indir1_block == NULL) {
1669 			ext4fs_indir1_block = zalloc(blksz);
1670 			if (ext4fs_indir1_block == NULL) {
1671 				printf("** SI ext2fs read block (indir 1)"
1672 					"malloc failed. **\n");
1673 				return -1;
1674 			}
1675 			ext4fs_indir1_size = blksz;
1676 			ext4fs_indir1_blkno = -1;
1677 		}
1678 		if (blksz != ext4fs_indir1_size) {
1679 			free(ext4fs_indir1_block);
1680 			ext4fs_indir1_block = NULL;
1681 			ext4fs_indir1_size = 0;
1682 			ext4fs_indir1_blkno = -1;
1683 			ext4fs_indir1_block = zalloc(blksz);
1684 			if (ext4fs_indir1_block == NULL) {
1685 				printf("** SI ext2fs read block (indir 1):"
1686 					"malloc failed. **\n");
1687 				return -1;
1688 			}
1689 			ext4fs_indir1_size = blksz;
1690 		}
1691 		if ((le32_to_cpu(inode->b.blocks.indir_block) <<
1692 		     log2_blksz) != ext4fs_indir1_blkno) {
1693 			status =
1694 			    ext4fs_devread((lbaint_t)le32_to_cpu
1695 					   (inode->b.blocks.
1696 					    indir_block) << log2_blksz, 0,
1697 					   blksz, (char *)ext4fs_indir1_block);
1698 			if (status == 0) {
1699 				printf("** SI ext2fs read block (indir 1)"
1700 					"failed. **\n");
1701 				return -1;
1702 			}
1703 			ext4fs_indir1_blkno =
1704 				le32_to_cpu(inode->b.blocks.
1705 					       indir_block) << log2_blksz;
1706 		}
1707 		blknr = le32_to_cpu(ext4fs_indir1_block
1708 				      [fileblock - INDIRECT_BLOCKS]);
1709 	}
1710 	/* Double indirect. */
1711 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
1712 					(blksz / 4 + 1)))) {
1713 
1714 		long int perblock = blksz / 4;
1715 		long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
1716 
1717 		if (ext4fs_indir1_block == NULL) {
1718 			ext4fs_indir1_block = zalloc(blksz);
1719 			if (ext4fs_indir1_block == NULL) {
1720 				printf("** DI ext2fs read block (indir 2 1)"
1721 					"malloc failed. **\n");
1722 				return -1;
1723 			}
1724 			ext4fs_indir1_size = blksz;
1725 			ext4fs_indir1_blkno = -1;
1726 		}
1727 		if (blksz != ext4fs_indir1_size) {
1728 			free(ext4fs_indir1_block);
1729 			ext4fs_indir1_block = NULL;
1730 			ext4fs_indir1_size = 0;
1731 			ext4fs_indir1_blkno = -1;
1732 			ext4fs_indir1_block = zalloc(blksz);
1733 			if (ext4fs_indir1_block == NULL) {
1734 				printf("** DI ext2fs read block (indir 2 1)"
1735 					"malloc failed. **\n");
1736 				return -1;
1737 			}
1738 			ext4fs_indir1_size = blksz;
1739 		}
1740 		if ((le32_to_cpu(inode->b.blocks.double_indir_block) <<
1741 		     log2_blksz) != ext4fs_indir1_blkno) {
1742 			status =
1743 			    ext4fs_devread((lbaint_t)le32_to_cpu
1744 					   (inode->b.blocks.
1745 					    double_indir_block) << log2_blksz,
1746 					   0, blksz,
1747 					   (char *)ext4fs_indir1_block);
1748 			if (status == 0) {
1749 				printf("** DI ext2fs read block (indir 2 1)"
1750 					"failed. **\n");
1751 				return -1;
1752 			}
1753 			ext4fs_indir1_blkno =
1754 			    le32_to_cpu(inode->b.blocks.double_indir_block) <<
1755 			    log2_blksz;
1756 		}
1757 
1758 		if (ext4fs_indir2_block == NULL) {
1759 			ext4fs_indir2_block = zalloc(blksz);
1760 			if (ext4fs_indir2_block == NULL) {
1761 				printf("** DI ext2fs read block (indir 2 2)"
1762 					"malloc failed. **\n");
1763 				return -1;
1764 			}
1765 			ext4fs_indir2_size = blksz;
1766 			ext4fs_indir2_blkno = -1;
1767 		}
1768 		if (blksz != ext4fs_indir2_size) {
1769 			free(ext4fs_indir2_block);
1770 			ext4fs_indir2_block = NULL;
1771 			ext4fs_indir2_size = 0;
1772 			ext4fs_indir2_blkno = -1;
1773 			ext4fs_indir2_block = zalloc(blksz);
1774 			if (ext4fs_indir2_block == NULL) {
1775 				printf("** DI ext2fs read block (indir 2 2)"
1776 					"malloc failed. **\n");
1777 				return -1;
1778 			}
1779 			ext4fs_indir2_size = blksz;
1780 		}
1781 		if ((le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
1782 		     log2_blksz) != ext4fs_indir2_blkno) {
1783 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1784 						(ext4fs_indir1_block
1785 						 [rblock /
1786 						  perblock]) << log2_blksz, 0,
1787 						blksz,
1788 						(char *)ext4fs_indir2_block);
1789 			if (status == 0) {
1790 				printf("** DI ext2fs read block (indir 2 2)"
1791 					"failed. **\n");
1792 				return -1;
1793 			}
1794 			ext4fs_indir2_blkno =
1795 			    le32_to_cpu(ext4fs_indir1_block[rblock
1796 							      /
1797 							      perblock]) <<
1798 			    log2_blksz;
1799 		}
1800 		blknr = le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
1801 	}
1802 	/* Tripple indirect. */
1803 	else {
1804 		rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
1805 				      (blksz / 4 * blksz / 4));
1806 		perblock_child = blksz / 4;
1807 		perblock_parent = ((blksz / 4) * (blksz / 4));
1808 
1809 		if (ext4fs_indir1_block == NULL) {
1810 			ext4fs_indir1_block = zalloc(blksz);
1811 			if (ext4fs_indir1_block == NULL) {
1812 				printf("** TI ext2fs read block (indir 2 1)"
1813 					"malloc failed. **\n");
1814 				return -1;
1815 			}
1816 			ext4fs_indir1_size = blksz;
1817 			ext4fs_indir1_blkno = -1;
1818 		}
1819 		if (blksz != ext4fs_indir1_size) {
1820 			free(ext4fs_indir1_block);
1821 			ext4fs_indir1_block = NULL;
1822 			ext4fs_indir1_size = 0;
1823 			ext4fs_indir1_blkno = -1;
1824 			ext4fs_indir1_block = zalloc(blksz);
1825 			if (ext4fs_indir1_block == NULL) {
1826 				printf("** TI ext2fs read block (indir 2 1)"
1827 					"malloc failed. **\n");
1828 				return -1;
1829 			}
1830 			ext4fs_indir1_size = blksz;
1831 		}
1832 		if ((le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1833 		     log2_blksz) != ext4fs_indir1_blkno) {
1834 			status = ext4fs_devread
1835 			    ((lbaint_t)
1836 			     le32_to_cpu(inode->b.blocks.triple_indir_block)
1837 			     << log2_blksz, 0, blksz,
1838 			     (char *)ext4fs_indir1_block);
1839 			if (status == 0) {
1840 				printf("** TI ext2fs read block (indir 2 1)"
1841 					"failed. **\n");
1842 				return -1;
1843 			}
1844 			ext4fs_indir1_blkno =
1845 			    le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1846 			    log2_blksz;
1847 		}
1848 
1849 		if (ext4fs_indir2_block == NULL) {
1850 			ext4fs_indir2_block = zalloc(blksz);
1851 			if (ext4fs_indir2_block == NULL) {
1852 				printf("** TI ext2fs read block (indir 2 2)"
1853 					"malloc failed. **\n");
1854 				return -1;
1855 			}
1856 			ext4fs_indir2_size = blksz;
1857 			ext4fs_indir2_blkno = -1;
1858 		}
1859 		if (blksz != ext4fs_indir2_size) {
1860 			free(ext4fs_indir2_block);
1861 			ext4fs_indir2_block = NULL;
1862 			ext4fs_indir2_size = 0;
1863 			ext4fs_indir2_blkno = -1;
1864 			ext4fs_indir2_block = zalloc(blksz);
1865 			if (ext4fs_indir2_block == NULL) {
1866 				printf("** TI ext2fs read block (indir 2 2)"
1867 					"malloc failed. **\n");
1868 				return -1;
1869 			}
1870 			ext4fs_indir2_size = blksz;
1871 		}
1872 		if ((le32_to_cpu(ext4fs_indir1_block[rblock /
1873 						       perblock_parent]) <<
1874 		     log2_blksz)
1875 		    != ext4fs_indir2_blkno) {
1876 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1877 						(ext4fs_indir1_block
1878 						 [rblock /
1879 						  perblock_parent]) <<
1880 						log2_blksz, 0, blksz,
1881 						(char *)ext4fs_indir2_block);
1882 			if (status == 0) {
1883 				printf("** TI ext2fs read block (indir 2 2)"
1884 					"failed. **\n");
1885 				return -1;
1886 			}
1887 			ext4fs_indir2_blkno =
1888 			    le32_to_cpu(ext4fs_indir1_block[rblock /
1889 							      perblock_parent])
1890 			    << log2_blksz;
1891 		}
1892 
1893 		if (ext4fs_indir3_block == NULL) {
1894 			ext4fs_indir3_block = zalloc(blksz);
1895 			if (ext4fs_indir3_block == NULL) {
1896 				printf("** TI ext2fs read block (indir 2 2)"
1897 					"malloc failed. **\n");
1898 				return -1;
1899 			}
1900 			ext4fs_indir3_size = blksz;
1901 			ext4fs_indir3_blkno = -1;
1902 		}
1903 		if (blksz != ext4fs_indir3_size) {
1904 			free(ext4fs_indir3_block);
1905 			ext4fs_indir3_block = NULL;
1906 			ext4fs_indir3_size = 0;
1907 			ext4fs_indir3_blkno = -1;
1908 			ext4fs_indir3_block = zalloc(blksz);
1909 			if (ext4fs_indir3_block == NULL) {
1910 				printf("** TI ext2fs read block (indir 2 2)"
1911 					"malloc failed. **\n");
1912 				return -1;
1913 			}
1914 			ext4fs_indir3_size = blksz;
1915 		}
1916 		if ((le32_to_cpu(ext4fs_indir2_block[rblock
1917 						       /
1918 						       perblock_child]) <<
1919 		     log2_blksz) != ext4fs_indir3_blkno) {
1920 			status =
1921 			    ext4fs_devread((lbaint_t)le32_to_cpu
1922 					   (ext4fs_indir2_block
1923 					    [(rblock / perblock_child)
1924 					     % (blksz / 4)]) << log2_blksz, 0,
1925 					   blksz, (char *)ext4fs_indir3_block);
1926 			if (status == 0) {
1927 				printf("** TI ext2fs read block (indir 2 2)"
1928 				       "failed. **\n");
1929 				return -1;
1930 			}
1931 			ext4fs_indir3_blkno =
1932 			    le32_to_cpu(ext4fs_indir2_block[(rblock /
1933 							       perblock_child) %
1934 							      (blksz /
1935 							       4)]) <<
1936 			    log2_blksz;
1937 		}
1938 
1939 		blknr = le32_to_cpu(ext4fs_indir3_block
1940 				      [rblock % perblock_child]);
1941 	}
1942 	debug("read_allocated_block %ld\n", blknr);
1943 
1944 	return blknr;
1945 }
1946 
1947 /**
1948  * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's
1949  *			    global pointers
1950  *
1951  * This function assures that for a file with the same name but different size
1952  * the sequential store on the ext4 filesystem will be correct.
1953  *
1954  * In this function the global data, responsible for internal representation
1955  * of the ext4 data are initialized to the reset state. Without this, during
1956  * replacement of the smaller file with the bigger truncation of new file was
1957  * performed.
1958  */
1959 void ext4fs_reinit_global(void)
1960 {
1961 	if (ext4fs_indir1_block != NULL) {
1962 		free(ext4fs_indir1_block);
1963 		ext4fs_indir1_block = NULL;
1964 		ext4fs_indir1_size = 0;
1965 		ext4fs_indir1_blkno = -1;
1966 	}
1967 	if (ext4fs_indir2_block != NULL) {
1968 		free(ext4fs_indir2_block);
1969 		ext4fs_indir2_block = NULL;
1970 		ext4fs_indir2_size = 0;
1971 		ext4fs_indir2_blkno = -1;
1972 	}
1973 	if (ext4fs_indir3_block != NULL) {
1974 		free(ext4fs_indir3_block);
1975 		ext4fs_indir3_block = NULL;
1976 		ext4fs_indir3_size = 0;
1977 		ext4fs_indir3_blkno = -1;
1978 	}
1979 }
1980 void ext4fs_close(void)
1981 {
1982 	if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
1983 		ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
1984 		ext4fs_file = NULL;
1985 	}
1986 	if (ext4fs_root != NULL) {
1987 		free(ext4fs_root);
1988 		ext4fs_root = NULL;
1989 	}
1990 
1991 	ext4fs_reinit_global();
1992 }
1993 
1994 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
1995 				struct ext2fs_node **fnode, int *ftype)
1996 {
1997 	unsigned int fpos = 0;
1998 	int status;
1999 	loff_t actread;
2000 	struct ext2fs_node *diro = (struct ext2fs_node *) dir;
2001 
2002 #ifdef DEBUG
2003 	if (name != NULL)
2004 		printf("Iterate dir %s\n", name);
2005 #endif /* of DEBUG */
2006 	if (!diro->inode_read) {
2007 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2008 		if (status == 0)
2009 			return 0;
2010 	}
2011 	/* Search the file.  */
2012 	while (fpos < le32_to_cpu(diro->inode.size)) {
2013 		struct ext2_dirent dirent;
2014 
2015 		status = ext4fs_read_file(diro, fpos,
2016 					   sizeof(struct ext2_dirent),
2017 					   (char *)&dirent, &actread);
2018 		if (status < 0)
2019 			return 0;
2020 
2021 		if (dirent.direntlen == 0) {
2022 			printf("Failed to iterate over directory %s\n", name);
2023 			return 0;
2024 		}
2025 
2026 		if (dirent.namelen != 0) {
2027 			char filename[dirent.namelen + 1];
2028 			struct ext2fs_node *fdiro;
2029 			int type = FILETYPE_UNKNOWN;
2030 
2031 			status = ext4fs_read_file(diro,
2032 						  fpos +
2033 						  sizeof(struct ext2_dirent),
2034 						  dirent.namelen, filename,
2035 						  &actread);
2036 			if (status < 0)
2037 				return 0;
2038 
2039 			fdiro = zalloc(sizeof(struct ext2fs_node));
2040 			if (!fdiro)
2041 				return 0;
2042 
2043 			fdiro->data = diro->data;
2044 			fdiro->ino = le32_to_cpu(dirent.inode);
2045 
2046 			filename[dirent.namelen] = '\0';
2047 
2048 			if (dirent.filetype != FILETYPE_UNKNOWN) {
2049 				fdiro->inode_read = 0;
2050 
2051 				if (dirent.filetype == FILETYPE_DIRECTORY)
2052 					type = FILETYPE_DIRECTORY;
2053 				else if (dirent.filetype == FILETYPE_SYMLINK)
2054 					type = FILETYPE_SYMLINK;
2055 				else if (dirent.filetype == FILETYPE_REG)
2056 					type = FILETYPE_REG;
2057 			} else {
2058 				status = ext4fs_read_inode(diro->data,
2059 							   le32_to_cpu
2060 							   (dirent.inode),
2061 							   &fdiro->inode);
2062 				if (status == 0) {
2063 					free(fdiro);
2064 					return 0;
2065 				}
2066 				fdiro->inode_read = 1;
2067 
2068 				if ((le16_to_cpu(fdiro->inode.mode) &
2069 				     FILETYPE_INO_MASK) ==
2070 				    FILETYPE_INO_DIRECTORY) {
2071 					type = FILETYPE_DIRECTORY;
2072 				} else if ((le16_to_cpu(fdiro->inode.mode)
2073 					    & FILETYPE_INO_MASK) ==
2074 					   FILETYPE_INO_SYMLINK) {
2075 					type = FILETYPE_SYMLINK;
2076 				} else if ((le16_to_cpu(fdiro->inode.mode)
2077 					    & FILETYPE_INO_MASK) ==
2078 					   FILETYPE_INO_REG) {
2079 					type = FILETYPE_REG;
2080 				}
2081 			}
2082 #ifdef DEBUG
2083 			printf("iterate >%s<\n", filename);
2084 #endif /* of DEBUG */
2085 			if ((name != NULL) && (fnode != NULL)
2086 			    && (ftype != NULL)) {
2087 				if (strcmp(filename, name) == 0) {
2088 					*ftype = type;
2089 					*fnode = fdiro;
2090 					return 1;
2091 				}
2092 			} else {
2093 				if (fdiro->inode_read == 0) {
2094 					status = ext4fs_read_inode(diro->data,
2095 								 le32_to_cpu(
2096 								 dirent.inode),
2097 								 &fdiro->inode);
2098 					if (status == 0) {
2099 						free(fdiro);
2100 						return 0;
2101 					}
2102 					fdiro->inode_read = 1;
2103 				}
2104 				switch (type) {
2105 				case FILETYPE_DIRECTORY:
2106 					printf("<DIR> ");
2107 					break;
2108 				case FILETYPE_SYMLINK:
2109 					printf("<SYM> ");
2110 					break;
2111 				case FILETYPE_REG:
2112 					printf("      ");
2113 					break;
2114 				default:
2115 					printf("< ? > ");
2116 					break;
2117 				}
2118 				printf("%10u %s\n",
2119 				       le32_to_cpu(fdiro->inode.size),
2120 					filename);
2121 			}
2122 			free(fdiro);
2123 		}
2124 		fpos += le16_to_cpu(dirent.direntlen);
2125 	}
2126 	return 0;
2127 }
2128 
2129 static char *ext4fs_read_symlink(struct ext2fs_node *node)
2130 {
2131 	char *symlink;
2132 	struct ext2fs_node *diro = node;
2133 	int status;
2134 	loff_t actread;
2135 
2136 	if (!diro->inode_read) {
2137 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2138 		if (status == 0)
2139 			return NULL;
2140 	}
2141 	symlink = zalloc(le32_to_cpu(diro->inode.size) + 1);
2142 	if (!symlink)
2143 		return NULL;
2144 
2145 	if (le32_to_cpu(diro->inode.size) < sizeof(diro->inode.b.symlink)) {
2146 		strncpy(symlink, diro->inode.b.symlink,
2147 			 le32_to_cpu(diro->inode.size));
2148 	} else {
2149 		status = ext4fs_read_file(diro, 0,
2150 					   le32_to_cpu(diro->inode.size),
2151 					   symlink, &actread);
2152 		if ((status < 0) || (actread == 0)) {
2153 			free(symlink);
2154 			return NULL;
2155 		}
2156 	}
2157 	symlink[le32_to_cpu(diro->inode.size)] = '\0';
2158 	return symlink;
2159 }
2160 
2161 static int ext4fs_find_file1(const char *currpath,
2162 			     struct ext2fs_node *currroot,
2163 			     struct ext2fs_node **currfound, int *foundtype)
2164 {
2165 	char fpath[strlen(currpath) + 1];
2166 	char *name = fpath;
2167 	char *next;
2168 	int status;
2169 	int type = FILETYPE_DIRECTORY;
2170 	struct ext2fs_node *currnode = currroot;
2171 	struct ext2fs_node *oldnode = currroot;
2172 
2173 	strncpy(fpath, currpath, strlen(currpath) + 1);
2174 
2175 	/* Remove all leading slashes. */
2176 	while (*name == '/')
2177 		name++;
2178 
2179 	if (!*name) {
2180 		*currfound = currnode;
2181 		return 1;
2182 	}
2183 
2184 	for (;;) {
2185 		int found;
2186 
2187 		/* Extract the actual part from the pathname. */
2188 		next = strchr(name, '/');
2189 		if (next) {
2190 			/* Remove all leading slashes. */
2191 			while (*next == '/')
2192 				*(next++) = '\0';
2193 		}
2194 
2195 		if (type != FILETYPE_DIRECTORY) {
2196 			ext4fs_free_node(currnode, currroot);
2197 			return 0;
2198 		}
2199 
2200 		oldnode = currnode;
2201 
2202 		/* Iterate over the directory. */
2203 		found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
2204 		if (found == 0)
2205 			return 0;
2206 
2207 		if (found == -1)
2208 			break;
2209 
2210 		/* Read in the symlink and follow it. */
2211 		if (type == FILETYPE_SYMLINK) {
2212 			char *symlink;
2213 
2214 			/* Test if the symlink does not loop. */
2215 			if (++symlinknest == 8) {
2216 				ext4fs_free_node(currnode, currroot);
2217 				ext4fs_free_node(oldnode, currroot);
2218 				return 0;
2219 			}
2220 
2221 			symlink = ext4fs_read_symlink(currnode);
2222 			ext4fs_free_node(currnode, currroot);
2223 
2224 			if (!symlink) {
2225 				ext4fs_free_node(oldnode, currroot);
2226 				return 0;
2227 			}
2228 
2229 			debug("Got symlink >%s<\n", symlink);
2230 
2231 			if (symlink[0] == '/') {
2232 				ext4fs_free_node(oldnode, currroot);
2233 				oldnode = &ext4fs_root->diropen;
2234 			}
2235 
2236 			/* Lookup the node the symlink points to. */
2237 			status = ext4fs_find_file1(symlink, oldnode,
2238 						    &currnode, &type);
2239 
2240 			free(symlink);
2241 
2242 			if (status == 0) {
2243 				ext4fs_free_node(oldnode, currroot);
2244 				return 0;
2245 			}
2246 		}
2247 
2248 		ext4fs_free_node(oldnode, currroot);
2249 
2250 		/* Found the node! */
2251 		if (!next || *next == '\0') {
2252 			*currfound = currnode;
2253 			*foundtype = type;
2254 			return 1;
2255 		}
2256 		name = next;
2257 	}
2258 	return -1;
2259 }
2260 
2261 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
2262 	struct ext2fs_node **foundnode, int expecttype)
2263 {
2264 	int status;
2265 	int foundtype = FILETYPE_DIRECTORY;
2266 
2267 	symlinknest = 0;
2268 	if (!path)
2269 		return 0;
2270 
2271 	status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
2272 	if (status == 0)
2273 		return 0;
2274 
2275 	/* Check if the node that was found was of the expected type. */
2276 	if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
2277 		return 0;
2278 	else if ((expecttype == FILETYPE_DIRECTORY)
2279 		   && (foundtype != expecttype))
2280 		return 0;
2281 
2282 	return 1;
2283 }
2284 
2285 int ext4fs_open(const char *filename, loff_t *len)
2286 {
2287 	struct ext2fs_node *fdiro = NULL;
2288 	int status;
2289 
2290 	if (ext4fs_root == NULL)
2291 		return -1;
2292 
2293 	ext4fs_file = NULL;
2294 	status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
2295 				  FILETYPE_REG);
2296 	if (status == 0)
2297 		goto fail;
2298 
2299 	if (!fdiro->inode_read) {
2300 		status = ext4fs_read_inode(fdiro->data, fdiro->ino,
2301 				&fdiro->inode);
2302 		if (status == 0)
2303 			goto fail;
2304 	}
2305 	*len = le32_to_cpu(fdiro->inode.size);
2306 	ext4fs_file = fdiro;
2307 
2308 	return 0;
2309 fail:
2310 	ext4fs_free_node(fdiro, &ext4fs_root->diropen);
2311 
2312 	return -1;
2313 }
2314 
2315 int ext4fs_mount(unsigned part_length)
2316 {
2317 	struct ext2_data *data;
2318 	int status;
2319 	struct ext_filesystem *fs = get_fs();
2320 	data = zalloc(SUPERBLOCK_SIZE);
2321 	if (!data)
2322 		return 0;
2323 
2324 	/* Read the superblock. */
2325 	status = ext4_read_superblock((char *)&data->sblock);
2326 
2327 	if (status == 0)
2328 		goto fail;
2329 
2330 	/* Make sure this is an ext2 filesystem. */
2331 	if (le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
2332 		goto fail;
2333 
2334 
2335 	if (le32_to_cpu(data->sblock.revision_level) == 0) {
2336 		fs->inodesz = 128;
2337 		fs->gdsize = 32;
2338 	} else {
2339 		debug("EXT4 features COMPAT: %08x INCOMPAT: %08x RO_COMPAT: %08x\n",
2340 		      __le32_to_cpu(data->sblock.feature_compatibility),
2341 		      __le32_to_cpu(data->sblock.feature_incompat),
2342 		      __le32_to_cpu(data->sblock.feature_ro_compat));
2343 
2344 		fs->inodesz = le16_to_cpu(data->sblock.inode_size);
2345 		fs->gdsize = le32_to_cpu(data->sblock.feature_incompat) &
2346 			EXT4_FEATURE_INCOMPAT_64BIT ?
2347 			le16_to_cpu(data->sblock.descriptor_size) : 32;
2348 	}
2349 
2350 	debug("EXT2 rev %d, inode_size %d, descriptor size %d\n",
2351 	      le32_to_cpu(data->sblock.revision_level),
2352 	      fs->inodesz, fs->gdsize);
2353 
2354 	data->diropen.data = data;
2355 	data->diropen.ino = 2;
2356 	data->diropen.inode_read = 1;
2357 	data->inode = &data->diropen.inode;
2358 
2359 	status = ext4fs_read_inode(data, 2, data->inode);
2360 	if (status == 0)
2361 		goto fail;
2362 
2363 	ext4fs_root = data;
2364 
2365 	return 1;
2366 fail:
2367 	printf("Failed to mount ext2 filesystem...\n");
2368 	free(data);
2369 	ext4fs_root = NULL;
2370 
2371 	return 0;
2372 }
2373