xref: /openbmc/u-boot/fs/ext4/ext4_common.c (revision 32cd2512)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2011 - 2012 Samsung Electronics
4  * EXT4 filesystem implementation in Uboot by
5  * Uma Shankar <uma.shankar@samsung.com>
6  * Manjunatha C Achar <a.manjunatha@samsung.com>
7  *
8  * ext4ls and ext4load : Based on ext2 ls load support in Uboot.
9  *
10  * (C) Copyright 2004
11  * esd gmbh <www.esd-electronics.com>
12  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
13  *
14  * based on code from grub2 fs/ext2.c and fs/fshelp.c by
15  * GRUB  --  GRand Unified Bootloader
16  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
17  *
18  * ext4write : Based on generic ext4 protocol.
19  */
20 
21 #include <common.h>
22 #include <ext_common.h>
23 #include <ext4fs.h>
24 #include <malloc.h>
25 #include <memalign.h>
26 #include <stddef.h>
27 #include <linux/stat.h>
28 #include <linux/time.h>
29 #include <asm/byteorder.h>
30 #include "ext4_common.h"
31 
32 struct ext2_data *ext4fs_root;
33 struct ext2fs_node *ext4fs_file;
34 __le32 *ext4fs_indir1_block;
35 int ext4fs_indir1_size;
36 int ext4fs_indir1_blkno = -1;
37 __le32 *ext4fs_indir2_block;
38 int ext4fs_indir2_size;
39 int ext4fs_indir2_blkno = -1;
40 
41 __le32 *ext4fs_indir3_block;
42 int ext4fs_indir3_size;
43 int ext4fs_indir3_blkno = -1;
44 struct ext2_inode *g_parent_inode;
45 static int symlinknest;
46 
47 #if defined(CONFIG_EXT4_WRITE)
48 struct ext2_block_group *ext4fs_get_group_descriptor
49 	(const struct ext_filesystem *fs, uint32_t bg_idx)
50 {
51 	return (struct ext2_block_group *)(fs->gdtable + (bg_idx * fs->gdsize));
52 }
53 
54 static inline void ext4fs_sb_free_inodes_dec(struct ext2_sblock *sb)
55 {
56 	sb->free_inodes = cpu_to_le32(le32_to_cpu(sb->free_inodes) - 1);
57 }
58 
59 static inline void ext4fs_sb_free_blocks_dec(struct ext2_sblock *sb)
60 {
61 	uint64_t free_blocks = le32_to_cpu(sb->free_blocks);
62 	free_blocks += (uint64_t)le32_to_cpu(sb->free_blocks_high) << 32;
63 	free_blocks--;
64 
65 	sb->free_blocks = cpu_to_le32(free_blocks & 0xffffffff);
66 	sb->free_blocks_high = cpu_to_le16(free_blocks >> 32);
67 }
68 
69 static inline void ext4fs_bg_free_inodes_dec
70 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
71 {
72 	uint32_t free_inodes = le16_to_cpu(bg->free_inodes);
73 	if (fs->gdsize == 64)
74 		free_inodes += le16_to_cpu(bg->free_inodes_high) << 16;
75 	free_inodes--;
76 
77 	bg->free_inodes = cpu_to_le16(free_inodes & 0xffff);
78 	if (fs->gdsize == 64)
79 		bg->free_inodes_high = cpu_to_le16(free_inodes >> 16);
80 }
81 
82 static inline void ext4fs_bg_free_blocks_dec
83 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
84 {
85 	uint32_t free_blocks = le16_to_cpu(bg->free_blocks);
86 	if (fs->gdsize == 64)
87 		free_blocks += le16_to_cpu(bg->free_blocks_high) << 16;
88 	free_blocks--;
89 
90 	bg->free_blocks = cpu_to_le16(free_blocks & 0xffff);
91 	if (fs->gdsize == 64)
92 		bg->free_blocks_high = cpu_to_le16(free_blocks >> 16);
93 }
94 
95 static inline void ext4fs_bg_itable_unused_dec
96 	(struct ext2_block_group *bg, const struct ext_filesystem *fs)
97 {
98 	uint32_t free_inodes = le16_to_cpu(bg->bg_itable_unused);
99 	if (fs->gdsize == 64)
100 		free_inodes += le16_to_cpu(bg->bg_itable_unused_high) << 16;
101 	free_inodes--;
102 
103 	bg->bg_itable_unused = cpu_to_le16(free_inodes & 0xffff);
104 	if (fs->gdsize == 64)
105 		bg->bg_itable_unused_high = cpu_to_le16(free_inodes >> 16);
106 }
107 
108 uint64_t ext4fs_sb_get_free_blocks(const struct ext2_sblock *sb)
109 {
110 	uint64_t free_blocks = le32_to_cpu(sb->free_blocks);
111 	free_blocks += (uint64_t)le32_to_cpu(sb->free_blocks_high) << 32;
112 	return free_blocks;
113 }
114 
115 void ext4fs_sb_set_free_blocks(struct ext2_sblock *sb, uint64_t free_blocks)
116 {
117 	sb->free_blocks = cpu_to_le32(free_blocks & 0xffffffff);
118 	sb->free_blocks_high = cpu_to_le16(free_blocks >> 32);
119 }
120 
121 uint32_t ext4fs_bg_get_free_blocks(const struct ext2_block_group *bg,
122 				   const struct ext_filesystem *fs)
123 {
124 	uint32_t free_blocks = le16_to_cpu(bg->free_blocks);
125 	if (fs->gdsize == 64)
126 		free_blocks += le16_to_cpu(bg->free_blocks_high) << 16;
127 	return free_blocks;
128 }
129 
130 static inline
131 uint32_t ext4fs_bg_get_free_inodes(const struct ext2_block_group *bg,
132 				   const struct ext_filesystem *fs)
133 {
134 	uint32_t free_inodes = le16_to_cpu(bg->free_inodes);
135 	if (fs->gdsize == 64)
136 		free_inodes += le16_to_cpu(bg->free_inodes_high) << 16;
137 	return free_inodes;
138 }
139 
140 static inline uint16_t ext4fs_bg_get_flags(const struct ext2_block_group *bg)
141 {
142 	return le16_to_cpu(bg->bg_flags);
143 }
144 
145 static inline void ext4fs_bg_set_flags(struct ext2_block_group *bg,
146 				       uint16_t flags)
147 {
148 	bg->bg_flags = cpu_to_le16(flags);
149 }
150 
151 /* Block number of the block bitmap */
152 uint64_t ext4fs_bg_get_block_id(const struct ext2_block_group *bg,
153 				const struct ext_filesystem *fs)
154 {
155 	uint64_t block_nr = le32_to_cpu(bg->block_id);
156 	if (fs->gdsize == 64)
157 		block_nr += (uint64_t)le32_to_cpu(bg->block_id_high) << 32;
158 	return block_nr;
159 }
160 
161 /* Block number of the inode bitmap */
162 uint64_t ext4fs_bg_get_inode_id(const struct ext2_block_group *bg,
163 				const struct ext_filesystem *fs)
164 {
165 	uint64_t block_nr = le32_to_cpu(bg->inode_id);
166 	if (fs->gdsize == 64)
167 		block_nr += (uint64_t)le32_to_cpu(bg->inode_id_high) << 32;
168 	return block_nr;
169 }
170 #endif
171 
172 /* Block number of the inode table */
173 uint64_t ext4fs_bg_get_inode_table_id(const struct ext2_block_group *bg,
174 				      const struct ext_filesystem *fs)
175 {
176 	uint64_t block_nr = le32_to_cpu(bg->inode_table_id);
177 	if (fs->gdsize == 64)
178 		block_nr +=
179 			(uint64_t)le32_to_cpu(bg->inode_table_id_high) << 32;
180 	return block_nr;
181 }
182 
183 #if defined(CONFIG_EXT4_WRITE)
184 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n)
185 {
186 	uint32_t res = size / n;
187 	if (res * n != size)
188 		res++;
189 
190 	return res;
191 }
192 
193 void put_ext4(uint64_t off, void *buf, uint32_t size)
194 {
195 	uint64_t startblock;
196 	uint64_t remainder;
197 	unsigned char *temp_ptr = NULL;
198 	struct ext_filesystem *fs = get_fs();
199 	int log2blksz = fs->dev_desc->log2blksz;
200 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, sec_buf, fs->dev_desc->blksz);
201 
202 	startblock = off >> log2blksz;
203 	startblock += part_offset;
204 	remainder = off & (uint64_t)(fs->dev_desc->blksz - 1);
205 
206 	if (fs->dev_desc == NULL)
207 		return;
208 
209 	if ((startblock + (size >> log2blksz)) >
210 	    (part_offset + fs->total_sect)) {
211 		printf("part_offset is " LBAFU "\n", part_offset);
212 		printf("total_sector is %llu\n", fs->total_sect);
213 		printf("error: overflow occurs\n");
214 		return;
215 	}
216 
217 	if (remainder) {
218 		blk_dread(fs->dev_desc, startblock, 1, sec_buf);
219 		temp_ptr = sec_buf;
220 		memcpy((temp_ptr + remainder), (unsigned char *)buf, size);
221 		blk_dwrite(fs->dev_desc, startblock, 1, sec_buf);
222 	} else {
223 		if (size >> log2blksz != 0) {
224 			blk_dwrite(fs->dev_desc, startblock, size >> log2blksz,
225 				   (unsigned long *)buf);
226 		} else {
227 			blk_dread(fs->dev_desc, startblock, 1, sec_buf);
228 			temp_ptr = sec_buf;
229 			memcpy(temp_ptr, buf, size);
230 			blk_dwrite(fs->dev_desc, startblock, 1,
231 				   (unsigned long *)sec_buf);
232 		}
233 	}
234 }
235 
236 static int _get_new_inode_no(unsigned char *buffer)
237 {
238 	struct ext_filesystem *fs = get_fs();
239 	unsigned char input;
240 	int operand, status;
241 	int count = 1;
242 	int j = 0;
243 
244 	/* get the blocksize of the filesystem */
245 	unsigned char *ptr = buffer;
246 	while (*ptr == 255) {
247 		ptr++;
248 		count += 8;
249 		if (count > le32_to_cpu(ext4fs_root->sblock.inodes_per_group))
250 			return -1;
251 	}
252 
253 	for (j = 0; j < fs->blksz; j++) {
254 		input = *ptr;
255 		int i = 0;
256 		while (i <= 7) {
257 			operand = 1 << i;
258 			status = input & operand;
259 			if (status) {
260 				i++;
261 				count++;
262 			} else {
263 				*ptr |= operand;
264 				return count;
265 			}
266 		}
267 		ptr = ptr + 1;
268 	}
269 
270 	return -1;
271 }
272 
273 static int _get_new_blk_no(unsigned char *buffer)
274 {
275 	int operand;
276 	int count = 0;
277 	int i;
278 	unsigned char *ptr = buffer;
279 	struct ext_filesystem *fs = get_fs();
280 
281 	while (*ptr == 255) {
282 		ptr++;
283 		count += 8;
284 		if (count == (fs->blksz * 8))
285 			return -1;
286 	}
287 
288 	if (fs->blksz == 1024)
289 		count += 1;
290 
291 	for (i = 0; i <= 7; i++) {
292 		operand = 1 << i;
293 		if (*ptr & operand) {
294 			count++;
295 		} else {
296 			*ptr |= operand;
297 			return count;
298 		}
299 	}
300 
301 	return -1;
302 }
303 
304 int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index)
305 {
306 	int i, remainder, status;
307 	unsigned char *ptr = buffer;
308 	unsigned char operand;
309 	i = blockno / 8;
310 	remainder = blockno % 8;
311 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
312 
313 	i = i - (index * blocksize);
314 	if (blocksize != 1024) {
315 		ptr = ptr + i;
316 		operand = 1 << remainder;
317 		status = *ptr & operand;
318 		if (status)
319 			return -1;
320 
321 		*ptr = *ptr | operand;
322 		return 0;
323 	} else {
324 		if (remainder == 0) {
325 			ptr = ptr + i - 1;
326 			operand = (1 << 7);
327 		} else {
328 			ptr = ptr + i;
329 			operand = (1 << (remainder - 1));
330 		}
331 		status = *ptr & operand;
332 		if (status)
333 			return -1;
334 
335 		*ptr = *ptr | operand;
336 		return 0;
337 	}
338 }
339 
340 void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index)
341 {
342 	int i, remainder, status;
343 	unsigned char *ptr = buffer;
344 	unsigned char operand;
345 	i = blockno / 8;
346 	remainder = blockno % 8;
347 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
348 
349 	i = i - (index * blocksize);
350 	if (blocksize != 1024) {
351 		ptr = ptr + i;
352 		operand = (1 << remainder);
353 		status = *ptr & operand;
354 		if (status)
355 			*ptr = *ptr & ~(operand);
356 	} else {
357 		if (remainder == 0) {
358 			ptr = ptr + i - 1;
359 			operand = (1 << 7);
360 		} else {
361 			ptr = ptr + i;
362 			operand = (1 << (remainder - 1));
363 		}
364 		status = *ptr & operand;
365 		if (status)
366 			*ptr = *ptr & ~(operand);
367 	}
368 }
369 
370 int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index)
371 {
372 	int i, remainder, status;
373 	unsigned char *ptr = buffer;
374 	unsigned char operand;
375 
376 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
377 	i = inode_no / 8;
378 	remainder = inode_no % 8;
379 	if (remainder == 0) {
380 		ptr = ptr + i - 1;
381 		operand = (1 << 7);
382 	} else {
383 		ptr = ptr + i;
384 		operand = (1 << (remainder - 1));
385 	}
386 	status = *ptr & operand;
387 	if (status)
388 		return -1;
389 
390 	*ptr = *ptr | operand;
391 
392 	return 0;
393 }
394 
395 void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index)
396 {
397 	int i, remainder, status;
398 	unsigned char *ptr = buffer;
399 	unsigned char operand;
400 
401 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
402 	i = inode_no / 8;
403 	remainder = inode_no % 8;
404 	if (remainder == 0) {
405 		ptr = ptr + i - 1;
406 		operand = (1 << 7);
407 	} else {
408 		ptr = ptr + i;
409 		operand = (1 << (remainder - 1));
410 	}
411 	status = *ptr & operand;
412 	if (status)
413 		*ptr = *ptr & ~(operand);
414 }
415 
416 uint16_t ext4fs_checksum_update(uint32_t i)
417 {
418 	struct ext2_block_group *desc;
419 	struct ext_filesystem *fs = get_fs();
420 	uint16_t crc = 0;
421 	__le32 le32_i = cpu_to_le32(i);
422 
423 	desc = ext4fs_get_group_descriptor(fs, i);
424 	if (le32_to_cpu(fs->sb->feature_ro_compat) & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
425 		int offset = offsetof(struct ext2_block_group, bg_checksum);
426 
427 		crc = ext2fs_crc16(~0, fs->sb->unique_id,
428 				   sizeof(fs->sb->unique_id));
429 		crc = ext2fs_crc16(crc, &le32_i, sizeof(le32_i));
430 		crc = ext2fs_crc16(crc, desc, offset);
431 		offset += sizeof(desc->bg_checksum);	/* skip checksum */
432 		assert(offset == sizeof(*desc));
433 		if (offset < fs->gdsize) {
434 			crc = ext2fs_crc16(crc, (__u8 *)desc + offset,
435 					   fs->gdsize - offset);
436 		}
437 	}
438 
439 	return crc;
440 }
441 
442 static int check_void_in_dentry(struct ext2_dirent *dir, char *filename)
443 {
444 	int dentry_length;
445 	int sizeof_void_space;
446 	int new_entry_byte_reqd;
447 	short padding_factor = 0;
448 
449 	if (dir->namelen % 4 != 0)
450 		padding_factor = 4 - (dir->namelen % 4);
451 
452 	dentry_length = sizeof(struct ext2_dirent) +
453 			dir->namelen + padding_factor;
454 	sizeof_void_space = le16_to_cpu(dir->direntlen) - dentry_length;
455 	if (sizeof_void_space == 0)
456 		return 0;
457 
458 	padding_factor = 0;
459 	if (strlen(filename) % 4 != 0)
460 		padding_factor = 4 - (strlen(filename) % 4);
461 
462 	new_entry_byte_reqd = strlen(filename) +
463 	    sizeof(struct ext2_dirent) + padding_factor;
464 	if (sizeof_void_space >= new_entry_byte_reqd) {
465 		dir->direntlen = cpu_to_le16(dentry_length);
466 		return sizeof_void_space;
467 	}
468 
469 	return 0;
470 }
471 
472 int ext4fs_update_parent_dentry(char *filename, int file_type)
473 {
474 	unsigned int *zero_buffer = NULL;
475 	char *root_first_block_buffer = NULL;
476 	int blk_idx;
477 	long int first_block_no_of_root = 0;
478 	int totalbytes = 0;
479 	unsigned int new_entry_byte_reqd;
480 	int sizeof_void_space = 0;
481 	int templength = 0;
482 	int inodeno = -1;
483 	int status;
484 	struct ext_filesystem *fs = get_fs();
485 	/* directory entry */
486 	struct ext2_dirent *dir;
487 	char *temp_dir = NULL;
488 	uint32_t new_blk_no;
489 	uint32_t new_size;
490 	uint32_t new_blockcnt;
491 	uint32_t directory_blocks;
492 
493 	zero_buffer = zalloc(fs->blksz);
494 	if (!zero_buffer) {
495 		printf("No Memory\n");
496 		return -1;
497 	}
498 	root_first_block_buffer = zalloc(fs->blksz);
499 	if (!root_first_block_buffer) {
500 		free(zero_buffer);
501 		printf("No Memory\n");
502 		return -1;
503 	}
504 	new_entry_byte_reqd = ROUND(strlen(filename) +
505 				    sizeof(struct ext2_dirent), 4);
506 restart:
507 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
508 		LOG2_BLOCK_SIZE(ext4fs_root);
509 	blk_idx = directory_blocks - 1;
510 
511 restart_read:
512 	/* read the block no allocated to a file */
513 	first_block_no_of_root = read_allocated_block(g_parent_inode, blk_idx);
514 	if (first_block_no_of_root <= 0)
515 		goto fail;
516 
517 	status = ext4fs_devread((lbaint_t)first_block_no_of_root
518 				* fs->sect_perblk,
519 				0, fs->blksz, root_first_block_buffer);
520 	if (status == 0)
521 		goto fail;
522 
523 	if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
524 		goto fail;
525 	dir = (struct ext2_dirent *)root_first_block_buffer;
526 	totalbytes = 0;
527 
528 	while (le16_to_cpu(dir->direntlen) > 0) {
529 		unsigned short used_len = ROUND(dir->namelen +
530 		    sizeof(struct ext2_dirent), 4);
531 
532 		/* last entry of block */
533 		if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen)) {
534 
535 			/* check if new entry fits */
536 			if ((used_len + new_entry_byte_reqd) <=
537 			    le16_to_cpu(dir->direntlen)) {
538 				dir->direntlen = cpu_to_le16(used_len);
539 				break;
540 			} else {
541 				if (blk_idx > 0) {
542 					printf("Block full, trying previous\n");
543 					blk_idx--;
544 					goto restart_read;
545 				}
546 				printf("All blocks full: Allocate new\n");
547 
548 				if (le32_to_cpu(g_parent_inode->flags) &
549 						EXT4_EXTENTS_FL) {
550 					printf("Directory uses extents\n");
551 					goto fail;
552 				}
553 				if (directory_blocks >= INDIRECT_BLOCKS) {
554 					printf("Directory exceeds limit\n");
555 					goto fail;
556 				}
557 				new_blk_no = ext4fs_get_new_blk_no();
558 				if (new_blk_no == -1) {
559 					printf("no block left to assign\n");
560 					goto fail;
561 				}
562 				put_ext4((uint64_t)new_blk_no * fs->blksz, zero_buffer, fs->blksz);
563 				g_parent_inode->b.blocks.
564 					dir_blocks[directory_blocks] =
565 					cpu_to_le32(new_blk_no);
566 
567 				new_size = le32_to_cpu(g_parent_inode->size);
568 				new_size += fs->blksz;
569 				g_parent_inode->size = cpu_to_le32(new_size);
570 
571 				new_blockcnt = le32_to_cpu(g_parent_inode->blockcnt);
572 				new_blockcnt += fs->sect_perblk;
573 				g_parent_inode->blockcnt = cpu_to_le32(new_blockcnt);
574 
575 				if (ext4fs_put_metadata
576 				    (root_first_block_buffer,
577 				     first_block_no_of_root))
578 					goto fail;
579 				goto restart;
580 			}
581 		}
582 
583 		templength = le16_to_cpu(dir->direntlen);
584 		totalbytes = totalbytes + templength;
585 		sizeof_void_space = check_void_in_dentry(dir, filename);
586 		if (sizeof_void_space)
587 			break;
588 
589 		dir = (struct ext2_dirent *)((char *)dir + templength);
590 	}
591 
592 	/* make a pointer ready for creating next directory entry */
593 	templength = le16_to_cpu(dir->direntlen);
594 	totalbytes = totalbytes + templength;
595 	dir = (struct ext2_dirent *)((char *)dir + templength);
596 
597 	/* get the next available inode number */
598 	inodeno = ext4fs_get_new_inode_no();
599 	if (inodeno == -1) {
600 		printf("no inode left to assign\n");
601 		goto fail;
602 	}
603 	dir->inode = cpu_to_le32(inodeno);
604 	if (sizeof_void_space)
605 		dir->direntlen = cpu_to_le16(sizeof_void_space);
606 	else
607 		dir->direntlen = cpu_to_le16(fs->blksz - totalbytes);
608 
609 	dir->namelen = strlen(filename);
610 	dir->filetype = FILETYPE_REG;	/* regular file */
611 	temp_dir = (char *)dir;
612 	temp_dir = temp_dir + sizeof(struct ext2_dirent);
613 	memcpy(temp_dir, filename, strlen(filename));
614 
615 	/* update or write  the 1st block of root inode */
616 	if (ext4fs_put_metadata(root_first_block_buffer,
617 				first_block_no_of_root))
618 		goto fail;
619 
620 fail:
621 	free(zero_buffer);
622 	free(root_first_block_buffer);
623 
624 	return inodeno;
625 }
626 
627 static int search_dir(struct ext2_inode *parent_inode, char *dirname)
628 {
629 	int status;
630 	int inodeno = 0;
631 	int offset;
632 	int blk_idx;
633 	long int blknr;
634 	char *block_buffer = NULL;
635 	struct ext2_dirent *dir = NULL;
636 	struct ext_filesystem *fs = get_fs();
637 	uint32_t directory_blocks;
638 	char *direntname;
639 
640 	directory_blocks = le32_to_cpu(parent_inode->size) >>
641 		LOG2_BLOCK_SIZE(ext4fs_root);
642 
643 	block_buffer = zalloc(fs->blksz);
644 	if (!block_buffer)
645 		goto fail;
646 
647 	/* get the block no allocated to a file */
648 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
649 		blknr = read_allocated_block(parent_inode, blk_idx);
650 		if (blknr <= 0)
651 			goto fail;
652 
653 		/* read the directory block */
654 		status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk,
655 					0, fs->blksz, (char *)block_buffer);
656 		if (status == 0)
657 			goto fail;
658 
659 		offset = 0;
660 		do {
661 			if (offset & 3) {
662 				printf("Badly aligned ext2_dirent\n");
663 				break;
664 			}
665 
666 			dir = (struct ext2_dirent *)(block_buffer + offset);
667 			direntname = (char*)(dir) + sizeof(struct ext2_dirent);
668 
669 			int direntlen = le16_to_cpu(dir->direntlen);
670 			if (direntlen < sizeof(struct ext2_dirent))
671 				break;
672 
673 			if (dir->inode && (strlen(dirname) == dir->namelen) &&
674 			    (strncmp(dirname, direntname, dir->namelen) == 0)) {
675 				inodeno = le32_to_cpu(dir->inode);
676 				break;
677 			}
678 
679 			offset += direntlen;
680 
681 		} while (offset < fs->blksz);
682 
683 		if (inodeno > 0) {
684 			free(block_buffer);
685 			return inodeno;
686 		}
687 	}
688 
689 fail:
690 	free(block_buffer);
691 
692 	return -1;
693 }
694 
695 static int find_dir_depth(char *dirname)
696 {
697 	char *token = strtok(dirname, "/");
698 	int count = 0;
699 	while (token != NULL) {
700 		token = strtok(NULL, "/");
701 		count++;
702 	}
703 	return count + 1 + 1;
704 	/*
705 	 * for example  for string /home/temp
706 	 * depth=home(1)+temp(1)+1 extra for NULL;
707 	 * so count is 4;
708 	 */
709 }
710 
711 static int parse_path(char **arr, char *dirname)
712 {
713 	char *token = strtok(dirname, "/");
714 	int i = 0;
715 
716 	/* add root */
717 	arr[i] = zalloc(strlen("/") + 1);
718 	if (!arr[i])
719 		return -ENOMEM;
720 	memcpy(arr[i++], "/", strlen("/"));
721 
722 	/* add each path entry after root */
723 	while (token != NULL) {
724 		arr[i] = zalloc(strlen(token) + 1);
725 		if (!arr[i])
726 			return -ENOMEM;
727 		memcpy(arr[i++], token, strlen(token));
728 		token = strtok(NULL, "/");
729 	}
730 	arr[i] = NULL;
731 
732 	return 0;
733 }
734 
735 int ext4fs_iget(int inode_no, struct ext2_inode *inode)
736 {
737 	if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0)
738 		return -1;
739 
740 	return 0;
741 }
742 
743 /*
744  * Function: ext4fs_get_parent_inode_num
745  * Return Value: inode Number of the parent directory of  file/Directory to be
746  * created
747  * dirname : Input parmater, input path name of the file/directory to be created
748  * dname : Output parameter, to be filled with the name of the directory
749  * extracted from dirname
750  */
751 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags)
752 {
753 	int i;
754 	int depth = 0;
755 	int matched_inode_no;
756 	int result_inode_no = -1;
757 	char **ptr = NULL;
758 	char *depth_dirname = NULL;
759 	char *parse_dirname = NULL;
760 	struct ext2_inode *parent_inode = NULL;
761 	struct ext2_inode *first_inode = NULL;
762 	struct ext2_inode temp_inode;
763 
764 	if (*dirname != '/') {
765 		printf("Please supply Absolute path\n");
766 		return -1;
767 	}
768 
769 	/* TODO: input validation make equivalent to linux */
770 	depth_dirname = zalloc(strlen(dirname) + 1);
771 	if (!depth_dirname)
772 		return -ENOMEM;
773 
774 	memcpy(depth_dirname, dirname, strlen(dirname));
775 	depth = find_dir_depth(depth_dirname);
776 	parse_dirname = zalloc(strlen(dirname) + 1);
777 	if (!parse_dirname)
778 		goto fail;
779 	memcpy(parse_dirname, dirname, strlen(dirname));
780 
781 	/* allocate memory for each directory level */
782 	ptr = zalloc((depth) * sizeof(char *));
783 	if (!ptr)
784 		goto fail;
785 	if (parse_path(ptr, parse_dirname))
786 		goto fail;
787 	parent_inode = zalloc(sizeof(struct ext2_inode));
788 	if (!parent_inode)
789 		goto fail;
790 	first_inode = zalloc(sizeof(struct ext2_inode));
791 	if (!first_inode)
792 		goto fail;
793 	memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode));
794 	memcpy(first_inode, parent_inode, sizeof(struct ext2_inode));
795 	if (flags & F_FILE)
796 		result_inode_no = EXT2_ROOT_INO;
797 	for (i = 1; i < depth; i++) {
798 		matched_inode_no = search_dir(parent_inode, ptr[i]);
799 		if (matched_inode_no == -1) {
800 			if (ptr[i + 1] == NULL && i == 1) {
801 				result_inode_no = EXT2_ROOT_INO;
802 				goto end;
803 			} else {
804 				if (ptr[i + 1] == NULL)
805 					break;
806 				printf("Invalid path\n");
807 				result_inode_no = -1;
808 				goto fail;
809 			}
810 		} else {
811 			if (ptr[i + 1] != NULL) {
812 				memset(parent_inode, '\0',
813 				       sizeof(struct ext2_inode));
814 				if (ext4fs_iget(matched_inode_no,
815 						parent_inode)) {
816 					result_inode_no = -1;
817 					goto fail;
818 				}
819 				result_inode_no = matched_inode_no;
820 			} else {
821 				break;
822 			}
823 		}
824 	}
825 
826 end:
827 	if (i == 1)
828 		matched_inode_no = search_dir(first_inode, ptr[i]);
829 	else
830 		matched_inode_no = search_dir(parent_inode, ptr[i]);
831 
832 	if (matched_inode_no != -1) {
833 		ext4fs_iget(matched_inode_no, &temp_inode);
834 		if (le16_to_cpu(temp_inode.mode) & S_IFDIR) {
835 			printf("It is a Directory\n");
836 			result_inode_no = -1;
837 			goto fail;
838 		}
839 	}
840 
841 	if (strlen(ptr[i]) > 256) {
842 		result_inode_no = -1;
843 		goto fail;
844 	}
845 	memcpy(dname, ptr[i], strlen(ptr[i]));
846 
847 fail:
848 	free(depth_dirname);
849 	free(parse_dirname);
850 	for (i = 0; i < depth; i++) {
851 		if (!ptr[i])
852 			break;
853 		free(ptr[i]);
854 	}
855 	free(ptr);
856 	free(parent_inode);
857 	free(first_inode);
858 
859 	return result_inode_no;
860 }
861 
862 static int unlink_filename(char *filename, unsigned int blknr)
863 {
864 	int status;
865 	int inodeno = 0;
866 	int offset;
867 	char *block_buffer = NULL;
868 	struct ext2_dirent *dir = NULL;
869 	struct ext2_dirent *previous_dir;
870 	struct ext_filesystem *fs = get_fs();
871 	int ret = -1;
872 	char *direntname;
873 
874 	block_buffer = zalloc(fs->blksz);
875 	if (!block_buffer)
876 		return -ENOMEM;
877 
878 	/* read the directory block */
879 	status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0,
880 				fs->blksz, block_buffer);
881 	if (status == 0)
882 		goto fail;
883 
884 	offset = 0;
885 	do {
886 		if (offset & 3) {
887 			printf("Badly aligned ext2_dirent\n");
888 			break;
889 		}
890 
891 		previous_dir = dir;
892 		dir = (struct ext2_dirent *)(block_buffer + offset);
893 		direntname = (char *)(dir) + sizeof(struct ext2_dirent);
894 
895 		int direntlen = le16_to_cpu(dir->direntlen);
896 		if (direntlen < sizeof(struct ext2_dirent))
897 			break;
898 
899 		if (dir->inode && (strlen(filename) == dir->namelen) &&
900 		    (strncmp(direntname, filename, dir->namelen) == 0)) {
901 			inodeno = le32_to_cpu(dir->inode);
902 			break;
903 		}
904 
905 		offset += direntlen;
906 
907 	} while (offset < fs->blksz);
908 
909 	if (inodeno > 0) {
910 		printf("file found, deleting\n");
911 		if (ext4fs_log_journal(block_buffer, blknr))
912 			goto fail;
913 
914 		if (previous_dir) {
915 			/* merge dir entry with predecessor */
916 			uint16_t new_len;
917 			new_len = le16_to_cpu(previous_dir->direntlen);
918 			new_len += le16_to_cpu(dir->direntlen);
919 			previous_dir->direntlen = cpu_to_le16(new_len);
920 		} else {
921 			/* invalidate dir entry */
922 			dir->inode = 0;
923 		}
924 		if (ext4fs_put_metadata(block_buffer, blknr))
925 			goto fail;
926 		ret = inodeno;
927 	}
928 fail:
929 	free(block_buffer);
930 
931 	return ret;
932 }
933 
934 int ext4fs_filename_unlink(char *filename)
935 {
936 	int blk_idx;
937 	long int blknr = -1;
938 	int inodeno = -1;
939 	uint32_t directory_blocks;
940 
941 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
942 		LOG2_BLOCK_SIZE(ext4fs_root);
943 
944 	/* read the block no allocated to a file */
945 	for (blk_idx = 0; blk_idx < directory_blocks; blk_idx++) {
946 		blknr = read_allocated_block(g_parent_inode, blk_idx);
947 		if (blknr <= 0)
948 			break;
949 		inodeno = unlink_filename(filename, blknr);
950 		if (inodeno != -1)
951 			return inodeno;
952 	}
953 
954 	return -1;
955 }
956 
957 uint32_t ext4fs_get_new_blk_no(void)
958 {
959 	short i;
960 	short status;
961 	int remainder;
962 	unsigned int bg_idx;
963 	static int prev_bg_bitmap_index = -1;
964 	unsigned int blk_per_grp = le32_to_cpu(ext4fs_root->sblock.blocks_per_group);
965 	struct ext_filesystem *fs = get_fs();
966 	char *journal_buffer = zalloc(fs->blksz);
967 	char *zero_buffer = zalloc(fs->blksz);
968 	if (!journal_buffer || !zero_buffer)
969 		goto fail;
970 
971 	if (fs->first_pass_bbmap == 0) {
972 		for (i = 0; i < fs->no_blkgrp; i++) {
973 			struct ext2_block_group *bgd = NULL;
974 			bgd = ext4fs_get_group_descriptor(fs, i);
975 			if (ext4fs_bg_get_free_blocks(bgd, fs)) {
976 				uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
977 				uint64_t b_bitmap_blk =
978 					ext4fs_bg_get_block_id(bgd, fs);
979 				if (bg_flags & EXT4_BG_BLOCK_UNINIT) {
980 					memcpy(fs->blk_bmaps[i], zero_buffer,
981 					       fs->blksz);
982 					put_ext4(b_bitmap_blk * fs->blksz,
983 						 fs->blk_bmaps[i], fs->blksz);
984 					bg_flags &= ~EXT4_BG_BLOCK_UNINIT;
985 					ext4fs_bg_set_flags(bgd, bg_flags);
986 				}
987 				fs->curr_blkno =
988 				    _get_new_blk_no(fs->blk_bmaps[i]);
989 				if (fs->curr_blkno == -1)
990 					/* block bitmap is completely filled */
991 					continue;
992 				fs->curr_blkno = fs->curr_blkno +
993 						(i * fs->blksz * 8);
994 				fs->first_pass_bbmap++;
995 				ext4fs_bg_free_blocks_dec(bgd, fs);
996 				ext4fs_sb_free_blocks_dec(fs->sb);
997 				status = ext4fs_devread(b_bitmap_blk *
998 							fs->sect_perblk,
999 							0, fs->blksz,
1000 							journal_buffer);
1001 				if (status == 0)
1002 					goto fail;
1003 				if (ext4fs_log_journal(journal_buffer,
1004 						       b_bitmap_blk))
1005 					goto fail;
1006 				goto success;
1007 			} else {
1008 				debug("no space left on block group %d\n", i);
1009 			}
1010 		}
1011 
1012 		goto fail;
1013 	} else {
1014 		fs->curr_blkno++;
1015 restart:
1016 		/* get the blockbitmap index respective to blockno */
1017 		bg_idx = fs->curr_blkno / blk_per_grp;
1018 		if (fs->blksz == 1024) {
1019 			remainder = fs->curr_blkno % blk_per_grp;
1020 			if (!remainder)
1021 				bg_idx--;
1022 		}
1023 
1024 		/*
1025 		 * To skip completely filled block group bitmaps
1026 		 * Optimize the block allocation
1027 		 */
1028 		if (bg_idx >= fs->no_blkgrp)
1029 			goto fail;
1030 
1031 		struct ext2_block_group *bgd = NULL;
1032 		bgd = ext4fs_get_group_descriptor(fs, bg_idx);
1033 		if (ext4fs_bg_get_free_blocks(bgd, fs) == 0) {
1034 			debug("block group %u is full. Skipping\n", bg_idx);
1035 			fs->curr_blkno = (bg_idx + 1) * blk_per_grp;
1036 			if (fs->blksz == 1024)
1037 				fs->curr_blkno += 1;
1038 			goto restart;
1039 		}
1040 
1041 		uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1042 		uint64_t b_bitmap_blk = ext4fs_bg_get_block_id(bgd, fs);
1043 		if (bg_flags & EXT4_BG_BLOCK_UNINIT) {
1044 			memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz);
1045 			put_ext4(b_bitmap_blk * fs->blksz,
1046 				 zero_buffer, fs->blksz);
1047 			bg_flags &= ~EXT4_BG_BLOCK_UNINIT;
1048 			ext4fs_bg_set_flags(bgd, bg_flags);
1049 		}
1050 
1051 		if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx],
1052 				   bg_idx) != 0) {
1053 			debug("going for restart for the block no %ld %u\n",
1054 			      fs->curr_blkno, bg_idx);
1055 			fs->curr_blkno++;
1056 			goto restart;
1057 		}
1058 
1059 		/* journal backup */
1060 		if (prev_bg_bitmap_index != bg_idx) {
1061 			status = ext4fs_devread(b_bitmap_blk * fs->sect_perblk,
1062 						0, fs->blksz, journal_buffer);
1063 			if (status == 0)
1064 				goto fail;
1065 			if (ext4fs_log_journal(journal_buffer, b_bitmap_blk))
1066 				goto fail;
1067 
1068 			prev_bg_bitmap_index = bg_idx;
1069 		}
1070 		ext4fs_bg_free_blocks_dec(bgd, fs);
1071 		ext4fs_sb_free_blocks_dec(fs->sb);
1072 		goto success;
1073 	}
1074 success:
1075 	free(journal_buffer);
1076 	free(zero_buffer);
1077 
1078 	return fs->curr_blkno;
1079 fail:
1080 	free(journal_buffer);
1081 	free(zero_buffer);
1082 
1083 	return -1;
1084 }
1085 
1086 int ext4fs_get_new_inode_no(void)
1087 {
1088 	short i;
1089 	short status;
1090 	unsigned int ibmap_idx;
1091 	static int prev_inode_bitmap_index = -1;
1092 	unsigned int inodes_per_grp = le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
1093 	struct ext_filesystem *fs = get_fs();
1094 	char *journal_buffer = zalloc(fs->blksz);
1095 	char *zero_buffer = zalloc(fs->blksz);
1096 	if (!journal_buffer || !zero_buffer)
1097 		goto fail;
1098 	int has_gdt_chksum = le32_to_cpu(fs->sb->feature_ro_compat) &
1099 		EXT4_FEATURE_RO_COMPAT_GDT_CSUM ? 1 : 0;
1100 
1101 	if (fs->first_pass_ibmap == 0) {
1102 		for (i = 0; i < fs->no_blkgrp; i++) {
1103 			uint32_t free_inodes;
1104 			struct ext2_block_group *bgd = NULL;
1105 			bgd = ext4fs_get_group_descriptor(fs, i);
1106 			free_inodes = ext4fs_bg_get_free_inodes(bgd, fs);
1107 			if (free_inodes) {
1108 				uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1109 				uint64_t i_bitmap_blk =
1110 					ext4fs_bg_get_inode_id(bgd, fs);
1111 				if (has_gdt_chksum)
1112 					bgd->bg_itable_unused = free_inodes;
1113 				if (bg_flags & EXT4_BG_INODE_UNINIT) {
1114 					put_ext4(i_bitmap_blk * fs->blksz,
1115 						 zero_buffer, fs->blksz);
1116 					bg_flags &= ~EXT4_BG_INODE_UNINIT;
1117 					ext4fs_bg_set_flags(bgd, bg_flags);
1118 					memcpy(fs->inode_bmaps[i],
1119 					       zero_buffer, fs->blksz);
1120 				}
1121 				fs->curr_inode_no =
1122 				    _get_new_inode_no(fs->inode_bmaps[i]);
1123 				if (fs->curr_inode_no == -1)
1124 					/* inode bitmap is completely filled */
1125 					continue;
1126 				fs->curr_inode_no = fs->curr_inode_no +
1127 							(i * inodes_per_grp);
1128 				fs->first_pass_ibmap++;
1129 				ext4fs_bg_free_inodes_dec(bgd, fs);
1130 				if (has_gdt_chksum)
1131 					ext4fs_bg_itable_unused_dec(bgd, fs);
1132 				ext4fs_sb_free_inodes_dec(fs->sb);
1133 				status = ext4fs_devread(i_bitmap_blk *
1134 							fs->sect_perblk,
1135 							0, fs->blksz,
1136 							journal_buffer);
1137 				if (status == 0)
1138 					goto fail;
1139 				if (ext4fs_log_journal(journal_buffer,
1140 						       i_bitmap_blk))
1141 					goto fail;
1142 				goto success;
1143 			} else
1144 				debug("no inode left on block group %d\n", i);
1145 		}
1146 		goto fail;
1147 	} else {
1148 restart:
1149 		fs->curr_inode_no++;
1150 		/* get the blockbitmap index respective to blockno */
1151 		ibmap_idx = fs->curr_inode_no / inodes_per_grp;
1152 		struct ext2_block_group *bgd =
1153 			ext4fs_get_group_descriptor(fs, ibmap_idx);
1154 		uint16_t bg_flags = ext4fs_bg_get_flags(bgd);
1155 		uint64_t i_bitmap_blk = ext4fs_bg_get_inode_id(bgd, fs);
1156 
1157 		if (bg_flags & EXT4_BG_INODE_UNINIT) {
1158 			put_ext4(i_bitmap_blk * fs->blksz,
1159 				 zero_buffer, fs->blksz);
1160 			bg_flags &= ~EXT4_BG_INODE_UNINIT;
1161 			ext4fs_bg_set_flags(bgd, bg_flags);
1162 			memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer,
1163 				fs->blksz);
1164 		}
1165 
1166 		if (ext4fs_set_inode_bmap(fs->curr_inode_no,
1167 					  fs->inode_bmaps[ibmap_idx],
1168 					  ibmap_idx) != 0) {
1169 			debug("going for restart for the block no %d %u\n",
1170 			      fs->curr_inode_no, ibmap_idx);
1171 			goto restart;
1172 		}
1173 
1174 		/* journal backup */
1175 		if (prev_inode_bitmap_index != ibmap_idx) {
1176 			status = ext4fs_devread(i_bitmap_blk * fs->sect_perblk,
1177 						0, fs->blksz, journal_buffer);
1178 			if (status == 0)
1179 				goto fail;
1180 			if (ext4fs_log_journal(journal_buffer,
1181 						le32_to_cpu(bgd->inode_id)))
1182 				goto fail;
1183 			prev_inode_bitmap_index = ibmap_idx;
1184 		}
1185 		ext4fs_bg_free_inodes_dec(bgd, fs);
1186 		if (has_gdt_chksum)
1187 			bgd->bg_itable_unused = bgd->free_inodes;
1188 		ext4fs_sb_free_inodes_dec(fs->sb);
1189 		goto success;
1190 	}
1191 
1192 success:
1193 	free(journal_buffer);
1194 	free(zero_buffer);
1195 
1196 	return fs->curr_inode_no;
1197 fail:
1198 	free(journal_buffer);
1199 	free(zero_buffer);
1200 
1201 	return -1;
1202 
1203 }
1204 
1205 
1206 static void alloc_single_indirect_block(struct ext2_inode *file_inode,
1207 					unsigned int *total_remaining_blocks,
1208 					unsigned int *no_blks_reqd)
1209 {
1210 	short i;
1211 	short status;
1212 	long int actual_block_no;
1213 	long int si_blockno;
1214 	/* si :single indirect */
1215 	__le32 *si_buffer = NULL;
1216 	__le32 *si_start_addr = NULL;
1217 	struct ext_filesystem *fs = get_fs();
1218 
1219 	if (*total_remaining_blocks != 0) {
1220 		si_buffer = zalloc(fs->blksz);
1221 		if (!si_buffer) {
1222 			printf("No Memory\n");
1223 			return;
1224 		}
1225 		si_start_addr = si_buffer;
1226 		si_blockno = ext4fs_get_new_blk_no();
1227 		if (si_blockno == -1) {
1228 			printf("no block left to assign\n");
1229 			goto fail;
1230 		}
1231 		(*no_blks_reqd)++;
1232 		debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks);
1233 
1234 		status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk,
1235 					0, fs->blksz, (char *)si_buffer);
1236 		memset(si_buffer, '\0', fs->blksz);
1237 		if (status == 0)
1238 			goto fail;
1239 
1240 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1241 			actual_block_no = ext4fs_get_new_blk_no();
1242 			if (actual_block_no == -1) {
1243 				printf("no block left to assign\n");
1244 				goto fail;
1245 			}
1246 			*si_buffer = cpu_to_le32(actual_block_no);
1247 			debug("SIAB %u: %u\n", *si_buffer,
1248 				*total_remaining_blocks);
1249 
1250 			si_buffer++;
1251 			(*total_remaining_blocks)--;
1252 			if (*total_remaining_blocks == 0)
1253 				break;
1254 		}
1255 
1256 		/* write the block to disk */
1257 		put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)),
1258 			 si_start_addr, fs->blksz);
1259 		file_inode->b.blocks.indir_block = cpu_to_le32(si_blockno);
1260 	}
1261 fail:
1262 	free(si_start_addr);
1263 }
1264 
1265 static void alloc_double_indirect_block(struct ext2_inode *file_inode,
1266 					unsigned int *total_remaining_blocks,
1267 					unsigned int *no_blks_reqd)
1268 {
1269 	short i;
1270 	short j;
1271 	short status;
1272 	long int actual_block_no;
1273 	/* di:double indirect */
1274 	long int di_blockno_parent;
1275 	long int di_blockno_child;
1276 	__le32 *di_parent_buffer = NULL;
1277 	__le32 *di_child_buff = NULL;
1278 	__le32 *di_block_start_addr = NULL;
1279 	__le32 *di_child_buff_start = NULL;
1280 	struct ext_filesystem *fs = get_fs();
1281 
1282 	if (*total_remaining_blocks != 0) {
1283 		/* double indirect parent block connecting to inode */
1284 		di_blockno_parent = ext4fs_get_new_blk_no();
1285 		if (di_blockno_parent == -1) {
1286 			printf("no block left to assign\n");
1287 			goto fail;
1288 		}
1289 		di_parent_buffer = zalloc(fs->blksz);
1290 		if (!di_parent_buffer)
1291 			goto fail;
1292 
1293 		di_block_start_addr = di_parent_buffer;
1294 		(*no_blks_reqd)++;
1295 		debug("DIPB %ld: %u\n", di_blockno_parent,
1296 		      *total_remaining_blocks);
1297 
1298 		status = ext4fs_devread((lbaint_t)di_blockno_parent *
1299 					fs->sect_perblk, 0,
1300 					fs->blksz, (char *)di_parent_buffer);
1301 
1302 		if (!status) {
1303 			printf("%s: Device read error!\n", __func__);
1304 			goto fail;
1305 		}
1306 		memset(di_parent_buffer, '\0', fs->blksz);
1307 
1308 		/*
1309 		 * start:for each double indirect parent
1310 		 * block create one more block
1311 		 */
1312 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1313 			di_blockno_child = ext4fs_get_new_blk_no();
1314 			if (di_blockno_child == -1) {
1315 				printf("no block left to assign\n");
1316 				goto fail;
1317 			}
1318 			di_child_buff = zalloc(fs->blksz);
1319 			if (!di_child_buff)
1320 				goto fail;
1321 
1322 			di_child_buff_start = di_child_buff;
1323 			*di_parent_buffer = cpu_to_le32(di_blockno_child);
1324 			di_parent_buffer++;
1325 			(*no_blks_reqd)++;
1326 			debug("DICB %ld: %u\n", di_blockno_child,
1327 			      *total_remaining_blocks);
1328 
1329 			status = ext4fs_devread((lbaint_t)di_blockno_child *
1330 						fs->sect_perblk, 0,
1331 						fs->blksz,
1332 						(char *)di_child_buff);
1333 
1334 			if (!status) {
1335 				printf("%s: Device read error!\n", __func__);
1336 				goto fail;
1337 			}
1338 			memset(di_child_buff, '\0', fs->blksz);
1339 			/* filling of actual datablocks for each child */
1340 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1341 				actual_block_no = ext4fs_get_new_blk_no();
1342 				if (actual_block_no == -1) {
1343 					printf("no block left to assign\n");
1344 					goto fail;
1345 				}
1346 				*di_child_buff = cpu_to_le32(actual_block_no);
1347 				debug("DIAB %ld: %u\n", actual_block_no,
1348 				      *total_remaining_blocks);
1349 
1350 				di_child_buff++;
1351 				(*total_remaining_blocks)--;
1352 				if (*total_remaining_blocks == 0)
1353 					break;
1354 			}
1355 			/* write the block  table */
1356 			put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)),
1357 				 di_child_buff_start, fs->blksz);
1358 			free(di_child_buff_start);
1359 			di_child_buff_start = NULL;
1360 
1361 			if (*total_remaining_blocks == 0)
1362 				break;
1363 		}
1364 		put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)),
1365 			 di_block_start_addr, fs->blksz);
1366 		file_inode->b.blocks.double_indir_block = cpu_to_le32(di_blockno_parent);
1367 	}
1368 fail:
1369 	free(di_block_start_addr);
1370 }
1371 
1372 static void alloc_triple_indirect_block(struct ext2_inode *file_inode,
1373 					unsigned int *total_remaining_blocks,
1374 					unsigned int *no_blks_reqd)
1375 {
1376 	short i;
1377 	short j;
1378 	short k;
1379 	long int actual_block_no;
1380 	/* ti: Triple Indirect */
1381 	long int ti_gp_blockno;
1382 	long int ti_parent_blockno;
1383 	long int ti_child_blockno;
1384 	__le32 *ti_gp_buff = NULL;
1385 	__le32 *ti_parent_buff = NULL;
1386 	__le32 *ti_child_buff = NULL;
1387 	__le32 *ti_gp_buff_start_addr = NULL;
1388 	__le32 *ti_pbuff_start_addr = NULL;
1389 	__le32 *ti_cbuff_start_addr = NULL;
1390 	struct ext_filesystem *fs = get_fs();
1391 	if (*total_remaining_blocks != 0) {
1392 		/* triple indirect grand parent block connecting to inode */
1393 		ti_gp_blockno = ext4fs_get_new_blk_no();
1394 		if (ti_gp_blockno == -1) {
1395 			printf("no block left to assign\n");
1396 			return;
1397 		}
1398 		ti_gp_buff = zalloc(fs->blksz);
1399 		if (!ti_gp_buff)
1400 			return;
1401 
1402 		ti_gp_buff_start_addr = ti_gp_buff;
1403 		(*no_blks_reqd)++;
1404 		debug("TIGPB %ld: %u\n", ti_gp_blockno,
1405 		      *total_remaining_blocks);
1406 
1407 		/* for each 4 byte grand parent entry create one more block */
1408 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1409 			ti_parent_blockno = ext4fs_get_new_blk_no();
1410 			if (ti_parent_blockno == -1) {
1411 				printf("no block left to assign\n");
1412 				goto fail;
1413 			}
1414 			ti_parent_buff = zalloc(fs->blksz);
1415 			if (!ti_parent_buff)
1416 				goto fail;
1417 
1418 			ti_pbuff_start_addr = ti_parent_buff;
1419 			*ti_gp_buff = cpu_to_le32(ti_parent_blockno);
1420 			ti_gp_buff++;
1421 			(*no_blks_reqd)++;
1422 			debug("TIPB %ld: %u\n", ti_parent_blockno,
1423 			      *total_remaining_blocks);
1424 
1425 			/* for each 4 byte entry parent create one more block */
1426 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1427 				ti_child_blockno = ext4fs_get_new_blk_no();
1428 				if (ti_child_blockno == -1) {
1429 					printf("no block left assign\n");
1430 					goto fail1;
1431 				}
1432 				ti_child_buff = zalloc(fs->blksz);
1433 				if (!ti_child_buff)
1434 					goto fail1;
1435 
1436 				ti_cbuff_start_addr = ti_child_buff;
1437 				*ti_parent_buff = cpu_to_le32(ti_child_blockno);
1438 				ti_parent_buff++;
1439 				(*no_blks_reqd)++;
1440 				debug("TICB %ld: %u\n", ti_parent_blockno,
1441 				      *total_remaining_blocks);
1442 
1443 				/* fill actual datablocks for each child */
1444 				for (k = 0; k < (fs->blksz / sizeof(int));
1445 					k++) {
1446 					actual_block_no =
1447 					    ext4fs_get_new_blk_no();
1448 					if (actual_block_no == -1) {
1449 						printf("no block left\n");
1450 						free(ti_cbuff_start_addr);
1451 						goto fail1;
1452 					}
1453 					*ti_child_buff = cpu_to_le32(actual_block_no);
1454 					debug("TIAB %ld: %u\n", actual_block_no,
1455 					      *total_remaining_blocks);
1456 
1457 					ti_child_buff++;
1458 					(*total_remaining_blocks)--;
1459 					if (*total_remaining_blocks == 0)
1460 						break;
1461 				}
1462 				/* write the child block */
1463 				put_ext4(((uint64_t) ((uint64_t)ti_child_blockno *
1464 						      (uint64_t)fs->blksz)),
1465 					 ti_cbuff_start_addr, fs->blksz);
1466 				free(ti_cbuff_start_addr);
1467 
1468 				if (*total_remaining_blocks == 0)
1469 					break;
1470 			}
1471 			/* write the parent block */
1472 			put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)),
1473 				 ti_pbuff_start_addr, fs->blksz);
1474 			free(ti_pbuff_start_addr);
1475 
1476 			if (*total_remaining_blocks == 0)
1477 				break;
1478 		}
1479 		/* write the grand parent block */
1480 		put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)),
1481 			 ti_gp_buff_start_addr, fs->blksz);
1482 		file_inode->b.blocks.triple_indir_block = cpu_to_le32(ti_gp_blockno);
1483 		free(ti_gp_buff_start_addr);
1484 		return;
1485 	}
1486 fail1:
1487 	free(ti_pbuff_start_addr);
1488 fail:
1489 	free(ti_gp_buff_start_addr);
1490 }
1491 
1492 void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
1493 				unsigned int total_remaining_blocks,
1494 				unsigned int *total_no_of_block)
1495 {
1496 	short i;
1497 	long int direct_blockno;
1498 	unsigned int no_blks_reqd = 0;
1499 
1500 	/* allocation of direct blocks */
1501 	for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) {
1502 		direct_blockno = ext4fs_get_new_blk_no();
1503 		if (direct_blockno == -1) {
1504 			printf("no block left to assign\n");
1505 			return;
1506 		}
1507 		file_inode->b.blocks.dir_blocks[i] = cpu_to_le32(direct_blockno);
1508 		debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);
1509 
1510 		total_remaining_blocks--;
1511 	}
1512 
1513 	alloc_single_indirect_block(file_inode, &total_remaining_blocks,
1514 				    &no_blks_reqd);
1515 	alloc_double_indirect_block(file_inode, &total_remaining_blocks,
1516 				    &no_blks_reqd);
1517 	alloc_triple_indirect_block(file_inode, &total_remaining_blocks,
1518 				    &no_blks_reqd);
1519 	*total_no_of_block += no_blks_reqd;
1520 }
1521 
1522 #endif
1523 
1524 static struct ext4_extent_header *ext4fs_get_extent_block
1525 	(struct ext2_data *data, char *buf,
1526 		struct ext4_extent_header *ext_block,
1527 		uint32_t fileblock, int log2_blksz)
1528 {
1529 	struct ext4_extent_idx *index;
1530 	unsigned long long block;
1531 	int blksz = EXT2_BLOCK_SIZE(data);
1532 	int i;
1533 
1534 	while (1) {
1535 		index = (struct ext4_extent_idx *)(ext_block + 1);
1536 
1537 		if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
1538 			return NULL;
1539 
1540 		if (ext_block->eh_depth == 0)
1541 			return ext_block;
1542 		i = -1;
1543 		do {
1544 			i++;
1545 			if (i >= le16_to_cpu(ext_block->eh_entries))
1546 				break;
1547 		} while (fileblock >= le32_to_cpu(index[i].ei_block));
1548 
1549 		if (--i < 0)
1550 			return NULL;
1551 
1552 		block = le16_to_cpu(index[i].ei_leaf_hi);
1553 		block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
1554 
1555 		if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz,
1556 				   buf))
1557 			ext_block = (struct ext4_extent_header *)buf;
1558 		else
1559 			return NULL;
1560 	}
1561 }
1562 
1563 static int ext4fs_blockgroup
1564 	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
1565 {
1566 	long int blkno;
1567 	unsigned int blkoff, desc_per_blk;
1568 	int log2blksz = get_fs()->dev_desc->log2blksz;
1569 	int desc_size = get_fs()->gdsize;
1570 
1571 	desc_per_blk = EXT2_BLOCK_SIZE(data) / desc_size;
1572 
1573 	blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
1574 			group / desc_per_blk;
1575 	blkoff = (group % desc_per_blk) * desc_size;
1576 
1577 	debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
1578 	      group, blkno, blkoff);
1579 
1580 	return ext4fs_devread((lbaint_t)blkno <<
1581 			      (LOG2_BLOCK_SIZE(data) - log2blksz),
1582 			      blkoff, desc_size, (char *)blkgrp);
1583 }
1584 
1585 int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
1586 {
1587 	struct ext2_block_group blkgrp;
1588 	struct ext2_sblock *sblock = &data->sblock;
1589 	struct ext_filesystem *fs = get_fs();
1590 	int log2blksz = get_fs()->dev_desc->log2blksz;
1591 	int inodes_per_block, status;
1592 	long int blkno;
1593 	unsigned int blkoff;
1594 
1595 	/* It is easier to calculate if the first inode is 0. */
1596 	ino--;
1597 	status = ext4fs_blockgroup(data, ino / le32_to_cpu
1598 				   (sblock->inodes_per_group), &blkgrp);
1599 	if (status == 0)
1600 		return 0;
1601 
1602 	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
1603 	blkno = ext4fs_bg_get_inode_table_id(&blkgrp, fs) +
1604 	    (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1605 	blkoff = (ino % inodes_per_block) * fs->inodesz;
1606 	/* Read the inode. */
1607 	status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) -
1608 				log2blksz), blkoff,
1609 				sizeof(struct ext2_inode), (char *)inode);
1610 	if (status == 0)
1611 		return 0;
1612 
1613 	return 1;
1614 }
1615 
1616 long int read_allocated_block(struct ext2_inode *inode, int fileblock)
1617 {
1618 	long int blknr;
1619 	int blksz;
1620 	int log2_blksz;
1621 	int status;
1622 	long int rblock;
1623 	long int perblock_parent;
1624 	long int perblock_child;
1625 	unsigned long long start;
1626 	/* get the blocksize of the filesystem */
1627 	blksz = EXT2_BLOCK_SIZE(ext4fs_root);
1628 	log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
1629 		- get_fs()->dev_desc->log2blksz;
1630 
1631 	if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
1632 		long int startblock, endblock;
1633 		char *buf = zalloc(blksz);
1634 		if (!buf)
1635 			return -ENOMEM;
1636 		struct ext4_extent_header *ext_block;
1637 		struct ext4_extent *extent;
1638 		int i;
1639 		ext_block =
1640 			ext4fs_get_extent_block(ext4fs_root, buf,
1641 						(struct ext4_extent_header *)
1642 						inode->b.blocks.dir_blocks,
1643 						fileblock, log2_blksz);
1644 		if (!ext_block) {
1645 			printf("invalid extent block\n");
1646 			free(buf);
1647 			return -EINVAL;
1648 		}
1649 
1650 		extent = (struct ext4_extent *)(ext_block + 1);
1651 
1652 		for (i = 0; i < le16_to_cpu(ext_block->eh_entries); i++) {
1653 			startblock = le32_to_cpu(extent[i].ee_block);
1654 			endblock = startblock + le16_to_cpu(extent[i].ee_len);
1655 
1656 			if (startblock > fileblock) {
1657 				/* Sparse file */
1658 				free(buf);
1659 				return 0;
1660 
1661 			} else if (fileblock < endblock) {
1662 				start = le16_to_cpu(extent[i].ee_start_hi);
1663 				start = (start << 32) +
1664 					le32_to_cpu(extent[i].ee_start_lo);
1665 				free(buf);
1666 				return (fileblock - startblock) + start;
1667 			}
1668 		}
1669 
1670 		free(buf);
1671 		return 0;
1672 	}
1673 
1674 	/* Direct blocks. */
1675 	if (fileblock < INDIRECT_BLOCKS)
1676 		blknr = le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
1677 
1678 	/* Indirect. */
1679 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
1680 		if (ext4fs_indir1_block == NULL) {
1681 			ext4fs_indir1_block = zalloc(blksz);
1682 			if (ext4fs_indir1_block == NULL) {
1683 				printf("** SI ext2fs read block (indir 1)"
1684 					"malloc failed. **\n");
1685 				return -1;
1686 			}
1687 			ext4fs_indir1_size = blksz;
1688 			ext4fs_indir1_blkno = -1;
1689 		}
1690 		if (blksz != ext4fs_indir1_size) {
1691 			free(ext4fs_indir1_block);
1692 			ext4fs_indir1_block = NULL;
1693 			ext4fs_indir1_size = 0;
1694 			ext4fs_indir1_blkno = -1;
1695 			ext4fs_indir1_block = zalloc(blksz);
1696 			if (ext4fs_indir1_block == NULL) {
1697 				printf("** SI ext2fs read block (indir 1):"
1698 					"malloc failed. **\n");
1699 				return -1;
1700 			}
1701 			ext4fs_indir1_size = blksz;
1702 		}
1703 		if ((le32_to_cpu(inode->b.blocks.indir_block) <<
1704 		     log2_blksz) != ext4fs_indir1_blkno) {
1705 			status =
1706 			    ext4fs_devread((lbaint_t)le32_to_cpu
1707 					   (inode->b.blocks.
1708 					    indir_block) << log2_blksz, 0,
1709 					   blksz, (char *)ext4fs_indir1_block);
1710 			if (status == 0) {
1711 				printf("** SI ext2fs read block (indir 1)"
1712 					"failed. **\n");
1713 				return -1;
1714 			}
1715 			ext4fs_indir1_blkno =
1716 				le32_to_cpu(inode->b.blocks.
1717 					       indir_block) << log2_blksz;
1718 		}
1719 		blknr = le32_to_cpu(ext4fs_indir1_block
1720 				      [fileblock - INDIRECT_BLOCKS]);
1721 	}
1722 	/* Double indirect. */
1723 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
1724 					(blksz / 4 + 1)))) {
1725 
1726 		long int perblock = blksz / 4;
1727 		long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
1728 
1729 		if (ext4fs_indir1_block == NULL) {
1730 			ext4fs_indir1_block = zalloc(blksz);
1731 			if (ext4fs_indir1_block == NULL) {
1732 				printf("** DI ext2fs read block (indir 2 1)"
1733 					"malloc failed. **\n");
1734 				return -1;
1735 			}
1736 			ext4fs_indir1_size = blksz;
1737 			ext4fs_indir1_blkno = -1;
1738 		}
1739 		if (blksz != ext4fs_indir1_size) {
1740 			free(ext4fs_indir1_block);
1741 			ext4fs_indir1_block = NULL;
1742 			ext4fs_indir1_size = 0;
1743 			ext4fs_indir1_blkno = -1;
1744 			ext4fs_indir1_block = zalloc(blksz);
1745 			if (ext4fs_indir1_block == NULL) {
1746 				printf("** DI ext2fs read block (indir 2 1)"
1747 					"malloc failed. **\n");
1748 				return -1;
1749 			}
1750 			ext4fs_indir1_size = blksz;
1751 		}
1752 		if ((le32_to_cpu(inode->b.blocks.double_indir_block) <<
1753 		     log2_blksz) != ext4fs_indir1_blkno) {
1754 			status =
1755 			    ext4fs_devread((lbaint_t)le32_to_cpu
1756 					   (inode->b.blocks.
1757 					    double_indir_block) << log2_blksz,
1758 					   0, blksz,
1759 					   (char *)ext4fs_indir1_block);
1760 			if (status == 0) {
1761 				printf("** DI ext2fs read block (indir 2 1)"
1762 					"failed. **\n");
1763 				return -1;
1764 			}
1765 			ext4fs_indir1_blkno =
1766 			    le32_to_cpu(inode->b.blocks.double_indir_block) <<
1767 			    log2_blksz;
1768 		}
1769 
1770 		if (ext4fs_indir2_block == NULL) {
1771 			ext4fs_indir2_block = zalloc(blksz);
1772 			if (ext4fs_indir2_block == NULL) {
1773 				printf("** DI ext2fs read block (indir 2 2)"
1774 					"malloc failed. **\n");
1775 				return -1;
1776 			}
1777 			ext4fs_indir2_size = blksz;
1778 			ext4fs_indir2_blkno = -1;
1779 		}
1780 		if (blksz != ext4fs_indir2_size) {
1781 			free(ext4fs_indir2_block);
1782 			ext4fs_indir2_block = NULL;
1783 			ext4fs_indir2_size = 0;
1784 			ext4fs_indir2_blkno = -1;
1785 			ext4fs_indir2_block = zalloc(blksz);
1786 			if (ext4fs_indir2_block == NULL) {
1787 				printf("** DI ext2fs read block (indir 2 2)"
1788 					"malloc failed. **\n");
1789 				return -1;
1790 			}
1791 			ext4fs_indir2_size = blksz;
1792 		}
1793 		if ((le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
1794 		     log2_blksz) != ext4fs_indir2_blkno) {
1795 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1796 						(ext4fs_indir1_block
1797 						 [rblock /
1798 						  perblock]) << log2_blksz, 0,
1799 						blksz,
1800 						(char *)ext4fs_indir2_block);
1801 			if (status == 0) {
1802 				printf("** DI ext2fs read block (indir 2 2)"
1803 					"failed. **\n");
1804 				return -1;
1805 			}
1806 			ext4fs_indir2_blkno =
1807 			    le32_to_cpu(ext4fs_indir1_block[rblock
1808 							      /
1809 							      perblock]) <<
1810 			    log2_blksz;
1811 		}
1812 		blknr = le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
1813 	}
1814 	/* Tripple indirect. */
1815 	else {
1816 		rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
1817 				      (blksz / 4 * blksz / 4));
1818 		perblock_child = blksz / 4;
1819 		perblock_parent = ((blksz / 4) * (blksz / 4));
1820 
1821 		if (ext4fs_indir1_block == NULL) {
1822 			ext4fs_indir1_block = zalloc(blksz);
1823 			if (ext4fs_indir1_block == NULL) {
1824 				printf("** TI ext2fs read block (indir 2 1)"
1825 					"malloc failed. **\n");
1826 				return -1;
1827 			}
1828 			ext4fs_indir1_size = blksz;
1829 			ext4fs_indir1_blkno = -1;
1830 		}
1831 		if (blksz != ext4fs_indir1_size) {
1832 			free(ext4fs_indir1_block);
1833 			ext4fs_indir1_block = NULL;
1834 			ext4fs_indir1_size = 0;
1835 			ext4fs_indir1_blkno = -1;
1836 			ext4fs_indir1_block = zalloc(blksz);
1837 			if (ext4fs_indir1_block == NULL) {
1838 				printf("** TI ext2fs read block (indir 2 1)"
1839 					"malloc failed. **\n");
1840 				return -1;
1841 			}
1842 			ext4fs_indir1_size = blksz;
1843 		}
1844 		if ((le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1845 		     log2_blksz) != ext4fs_indir1_blkno) {
1846 			status = ext4fs_devread
1847 			    ((lbaint_t)
1848 			     le32_to_cpu(inode->b.blocks.triple_indir_block)
1849 			     << log2_blksz, 0, blksz,
1850 			     (char *)ext4fs_indir1_block);
1851 			if (status == 0) {
1852 				printf("** TI ext2fs read block (indir 2 1)"
1853 					"failed. **\n");
1854 				return -1;
1855 			}
1856 			ext4fs_indir1_blkno =
1857 			    le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1858 			    log2_blksz;
1859 		}
1860 
1861 		if (ext4fs_indir2_block == NULL) {
1862 			ext4fs_indir2_block = zalloc(blksz);
1863 			if (ext4fs_indir2_block == NULL) {
1864 				printf("** TI ext2fs read block (indir 2 2)"
1865 					"malloc failed. **\n");
1866 				return -1;
1867 			}
1868 			ext4fs_indir2_size = blksz;
1869 			ext4fs_indir2_blkno = -1;
1870 		}
1871 		if (blksz != ext4fs_indir2_size) {
1872 			free(ext4fs_indir2_block);
1873 			ext4fs_indir2_block = NULL;
1874 			ext4fs_indir2_size = 0;
1875 			ext4fs_indir2_blkno = -1;
1876 			ext4fs_indir2_block = zalloc(blksz);
1877 			if (ext4fs_indir2_block == NULL) {
1878 				printf("** TI ext2fs read block (indir 2 2)"
1879 					"malloc failed. **\n");
1880 				return -1;
1881 			}
1882 			ext4fs_indir2_size = blksz;
1883 		}
1884 		if ((le32_to_cpu(ext4fs_indir1_block[rblock /
1885 						       perblock_parent]) <<
1886 		     log2_blksz)
1887 		    != ext4fs_indir2_blkno) {
1888 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1889 						(ext4fs_indir1_block
1890 						 [rblock /
1891 						  perblock_parent]) <<
1892 						log2_blksz, 0, blksz,
1893 						(char *)ext4fs_indir2_block);
1894 			if (status == 0) {
1895 				printf("** TI ext2fs read block (indir 2 2)"
1896 					"failed. **\n");
1897 				return -1;
1898 			}
1899 			ext4fs_indir2_blkno =
1900 			    le32_to_cpu(ext4fs_indir1_block[rblock /
1901 							      perblock_parent])
1902 			    << log2_blksz;
1903 		}
1904 
1905 		if (ext4fs_indir3_block == NULL) {
1906 			ext4fs_indir3_block = zalloc(blksz);
1907 			if (ext4fs_indir3_block == NULL) {
1908 				printf("** TI ext2fs read block (indir 2 2)"
1909 					"malloc failed. **\n");
1910 				return -1;
1911 			}
1912 			ext4fs_indir3_size = blksz;
1913 			ext4fs_indir3_blkno = -1;
1914 		}
1915 		if (blksz != ext4fs_indir3_size) {
1916 			free(ext4fs_indir3_block);
1917 			ext4fs_indir3_block = NULL;
1918 			ext4fs_indir3_size = 0;
1919 			ext4fs_indir3_blkno = -1;
1920 			ext4fs_indir3_block = zalloc(blksz);
1921 			if (ext4fs_indir3_block == NULL) {
1922 				printf("** TI ext2fs read block (indir 2 2)"
1923 					"malloc failed. **\n");
1924 				return -1;
1925 			}
1926 			ext4fs_indir3_size = blksz;
1927 		}
1928 		if ((le32_to_cpu(ext4fs_indir2_block[rblock
1929 						       /
1930 						       perblock_child]) <<
1931 		     log2_blksz) != ext4fs_indir3_blkno) {
1932 			status =
1933 			    ext4fs_devread((lbaint_t)le32_to_cpu
1934 					   (ext4fs_indir2_block
1935 					    [(rblock / perblock_child)
1936 					     % (blksz / 4)]) << log2_blksz, 0,
1937 					   blksz, (char *)ext4fs_indir3_block);
1938 			if (status == 0) {
1939 				printf("** TI ext2fs read block (indir 2 2)"
1940 				       "failed. **\n");
1941 				return -1;
1942 			}
1943 			ext4fs_indir3_blkno =
1944 			    le32_to_cpu(ext4fs_indir2_block[(rblock /
1945 							       perblock_child) %
1946 							      (blksz /
1947 							       4)]) <<
1948 			    log2_blksz;
1949 		}
1950 
1951 		blknr = le32_to_cpu(ext4fs_indir3_block
1952 				      [rblock % perblock_child]);
1953 	}
1954 	debug("read_allocated_block %ld\n", blknr);
1955 
1956 	return blknr;
1957 }
1958 
1959 /**
1960  * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's
1961  *			    global pointers
1962  *
1963  * This function assures that for a file with the same name but different size
1964  * the sequential store on the ext4 filesystem will be correct.
1965  *
1966  * In this function the global data, responsible for internal representation
1967  * of the ext4 data are initialized to the reset state. Without this, during
1968  * replacement of the smaller file with the bigger truncation of new file was
1969  * performed.
1970  */
1971 void ext4fs_reinit_global(void)
1972 {
1973 	if (ext4fs_indir1_block != NULL) {
1974 		free(ext4fs_indir1_block);
1975 		ext4fs_indir1_block = NULL;
1976 		ext4fs_indir1_size = 0;
1977 		ext4fs_indir1_blkno = -1;
1978 	}
1979 	if (ext4fs_indir2_block != NULL) {
1980 		free(ext4fs_indir2_block);
1981 		ext4fs_indir2_block = NULL;
1982 		ext4fs_indir2_size = 0;
1983 		ext4fs_indir2_blkno = -1;
1984 	}
1985 	if (ext4fs_indir3_block != NULL) {
1986 		free(ext4fs_indir3_block);
1987 		ext4fs_indir3_block = NULL;
1988 		ext4fs_indir3_size = 0;
1989 		ext4fs_indir3_blkno = -1;
1990 	}
1991 }
1992 void ext4fs_close(void)
1993 {
1994 	if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
1995 		ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
1996 		ext4fs_file = NULL;
1997 	}
1998 	if (ext4fs_root != NULL) {
1999 		free(ext4fs_root);
2000 		ext4fs_root = NULL;
2001 	}
2002 
2003 	ext4fs_reinit_global();
2004 }
2005 
2006 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
2007 				struct ext2fs_node **fnode, int *ftype)
2008 {
2009 	unsigned int fpos = 0;
2010 	int status;
2011 	loff_t actread;
2012 	struct ext2fs_node *diro = (struct ext2fs_node *) dir;
2013 
2014 #ifdef DEBUG
2015 	if (name != NULL)
2016 		printf("Iterate dir %s\n", name);
2017 #endif /* of DEBUG */
2018 	if (!diro->inode_read) {
2019 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2020 		if (status == 0)
2021 			return 0;
2022 	}
2023 	/* Search the file.  */
2024 	while (fpos < le32_to_cpu(diro->inode.size)) {
2025 		struct ext2_dirent dirent;
2026 
2027 		status = ext4fs_read_file(diro, fpos,
2028 					   sizeof(struct ext2_dirent),
2029 					   (char *)&dirent, &actread);
2030 		if (status < 0)
2031 			return 0;
2032 
2033 		if (dirent.direntlen == 0) {
2034 			printf("Failed to iterate over directory %s\n", name);
2035 			return 0;
2036 		}
2037 
2038 		if (dirent.namelen != 0) {
2039 			char filename[dirent.namelen + 1];
2040 			struct ext2fs_node *fdiro;
2041 			int type = FILETYPE_UNKNOWN;
2042 
2043 			status = ext4fs_read_file(diro,
2044 						  fpos +
2045 						  sizeof(struct ext2_dirent),
2046 						  dirent.namelen, filename,
2047 						  &actread);
2048 			if (status < 0)
2049 				return 0;
2050 
2051 			fdiro = zalloc(sizeof(struct ext2fs_node));
2052 			if (!fdiro)
2053 				return 0;
2054 
2055 			fdiro->data = diro->data;
2056 			fdiro->ino = le32_to_cpu(dirent.inode);
2057 
2058 			filename[dirent.namelen] = '\0';
2059 
2060 			if (dirent.filetype != FILETYPE_UNKNOWN) {
2061 				fdiro->inode_read = 0;
2062 
2063 				if (dirent.filetype == FILETYPE_DIRECTORY)
2064 					type = FILETYPE_DIRECTORY;
2065 				else if (dirent.filetype == FILETYPE_SYMLINK)
2066 					type = FILETYPE_SYMLINK;
2067 				else if (dirent.filetype == FILETYPE_REG)
2068 					type = FILETYPE_REG;
2069 			} else {
2070 				status = ext4fs_read_inode(diro->data,
2071 							   le32_to_cpu
2072 							   (dirent.inode),
2073 							   &fdiro->inode);
2074 				if (status == 0) {
2075 					free(fdiro);
2076 					return 0;
2077 				}
2078 				fdiro->inode_read = 1;
2079 
2080 				if ((le16_to_cpu(fdiro->inode.mode) &
2081 				     FILETYPE_INO_MASK) ==
2082 				    FILETYPE_INO_DIRECTORY) {
2083 					type = FILETYPE_DIRECTORY;
2084 				} else if ((le16_to_cpu(fdiro->inode.mode)
2085 					    & FILETYPE_INO_MASK) ==
2086 					   FILETYPE_INO_SYMLINK) {
2087 					type = FILETYPE_SYMLINK;
2088 				} else if ((le16_to_cpu(fdiro->inode.mode)
2089 					    & FILETYPE_INO_MASK) ==
2090 					   FILETYPE_INO_REG) {
2091 					type = FILETYPE_REG;
2092 				}
2093 			}
2094 #ifdef DEBUG
2095 			printf("iterate >%s<\n", filename);
2096 #endif /* of DEBUG */
2097 			if ((name != NULL) && (fnode != NULL)
2098 			    && (ftype != NULL)) {
2099 				if (strcmp(filename, name) == 0) {
2100 					*ftype = type;
2101 					*fnode = fdiro;
2102 					return 1;
2103 				}
2104 			} else {
2105 				if (fdiro->inode_read == 0) {
2106 					status = ext4fs_read_inode(diro->data,
2107 								 le32_to_cpu(
2108 								 dirent.inode),
2109 								 &fdiro->inode);
2110 					if (status == 0) {
2111 						free(fdiro);
2112 						return 0;
2113 					}
2114 					fdiro->inode_read = 1;
2115 				}
2116 				switch (type) {
2117 				case FILETYPE_DIRECTORY:
2118 					printf("<DIR> ");
2119 					break;
2120 				case FILETYPE_SYMLINK:
2121 					printf("<SYM> ");
2122 					break;
2123 				case FILETYPE_REG:
2124 					printf("      ");
2125 					break;
2126 				default:
2127 					printf("< ? > ");
2128 					break;
2129 				}
2130 				printf("%10u %s\n",
2131 				       le32_to_cpu(fdiro->inode.size),
2132 					filename);
2133 			}
2134 			free(fdiro);
2135 		}
2136 		fpos += le16_to_cpu(dirent.direntlen);
2137 	}
2138 	return 0;
2139 }
2140 
2141 static char *ext4fs_read_symlink(struct ext2fs_node *node)
2142 {
2143 	char *symlink;
2144 	struct ext2fs_node *diro = node;
2145 	int status;
2146 	loff_t actread;
2147 
2148 	if (!diro->inode_read) {
2149 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2150 		if (status == 0)
2151 			return NULL;
2152 	}
2153 	symlink = zalloc(le32_to_cpu(diro->inode.size) + 1);
2154 	if (!symlink)
2155 		return NULL;
2156 
2157 	if (le32_to_cpu(diro->inode.size) < sizeof(diro->inode.b.symlink)) {
2158 		strncpy(symlink, diro->inode.b.symlink,
2159 			 le32_to_cpu(diro->inode.size));
2160 	} else {
2161 		status = ext4fs_read_file(diro, 0,
2162 					   le32_to_cpu(diro->inode.size),
2163 					   symlink, &actread);
2164 		if ((status < 0) || (actread == 0)) {
2165 			free(symlink);
2166 			return NULL;
2167 		}
2168 	}
2169 	symlink[le32_to_cpu(diro->inode.size)] = '\0';
2170 	return symlink;
2171 }
2172 
2173 static int ext4fs_find_file1(const char *currpath,
2174 			     struct ext2fs_node *currroot,
2175 			     struct ext2fs_node **currfound, int *foundtype)
2176 {
2177 	char fpath[strlen(currpath) + 1];
2178 	char *name = fpath;
2179 	char *next;
2180 	int status;
2181 	int type = FILETYPE_DIRECTORY;
2182 	struct ext2fs_node *currnode = currroot;
2183 	struct ext2fs_node *oldnode = currroot;
2184 
2185 	strncpy(fpath, currpath, strlen(currpath) + 1);
2186 
2187 	/* Remove all leading slashes. */
2188 	while (*name == '/')
2189 		name++;
2190 
2191 	if (!*name) {
2192 		*currfound = currnode;
2193 		return 1;
2194 	}
2195 
2196 	for (;;) {
2197 		int found;
2198 
2199 		/* Extract the actual part from the pathname. */
2200 		next = strchr(name, '/');
2201 		if (next) {
2202 			/* Remove all leading slashes. */
2203 			while (*next == '/')
2204 				*(next++) = '\0';
2205 		}
2206 
2207 		if (type != FILETYPE_DIRECTORY) {
2208 			ext4fs_free_node(currnode, currroot);
2209 			return 0;
2210 		}
2211 
2212 		oldnode = currnode;
2213 
2214 		/* Iterate over the directory. */
2215 		found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
2216 		if (found == 0)
2217 			return 0;
2218 
2219 		if (found == -1)
2220 			break;
2221 
2222 		/* Read in the symlink and follow it. */
2223 		if (type == FILETYPE_SYMLINK) {
2224 			char *symlink;
2225 
2226 			/* Test if the symlink does not loop. */
2227 			if (++symlinknest == 8) {
2228 				ext4fs_free_node(currnode, currroot);
2229 				ext4fs_free_node(oldnode, currroot);
2230 				return 0;
2231 			}
2232 
2233 			symlink = ext4fs_read_symlink(currnode);
2234 			ext4fs_free_node(currnode, currroot);
2235 
2236 			if (!symlink) {
2237 				ext4fs_free_node(oldnode, currroot);
2238 				return 0;
2239 			}
2240 
2241 			debug("Got symlink >%s<\n", symlink);
2242 
2243 			if (symlink[0] == '/') {
2244 				ext4fs_free_node(oldnode, currroot);
2245 				oldnode = &ext4fs_root->diropen;
2246 			}
2247 
2248 			/* Lookup the node the symlink points to. */
2249 			status = ext4fs_find_file1(symlink, oldnode,
2250 						    &currnode, &type);
2251 
2252 			free(symlink);
2253 
2254 			if (status == 0) {
2255 				ext4fs_free_node(oldnode, currroot);
2256 				return 0;
2257 			}
2258 		}
2259 
2260 		ext4fs_free_node(oldnode, currroot);
2261 
2262 		/* Found the node! */
2263 		if (!next || *next == '\0') {
2264 			*currfound = currnode;
2265 			*foundtype = type;
2266 			return 1;
2267 		}
2268 		name = next;
2269 	}
2270 	return -1;
2271 }
2272 
2273 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
2274 	struct ext2fs_node **foundnode, int expecttype)
2275 {
2276 	int status;
2277 	int foundtype = FILETYPE_DIRECTORY;
2278 
2279 	symlinknest = 0;
2280 	if (!path)
2281 		return 0;
2282 
2283 	status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
2284 	if (status == 0)
2285 		return 0;
2286 
2287 	/* Check if the node that was found was of the expected type. */
2288 	if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
2289 		return 0;
2290 	else if ((expecttype == FILETYPE_DIRECTORY)
2291 		   && (foundtype != expecttype))
2292 		return 0;
2293 
2294 	return 1;
2295 }
2296 
2297 int ext4fs_open(const char *filename, loff_t *len)
2298 {
2299 	struct ext2fs_node *fdiro = NULL;
2300 	int status;
2301 
2302 	if (ext4fs_root == NULL)
2303 		return -1;
2304 
2305 	ext4fs_file = NULL;
2306 	status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
2307 				  FILETYPE_REG);
2308 	if (status == 0)
2309 		goto fail;
2310 
2311 	if (!fdiro->inode_read) {
2312 		status = ext4fs_read_inode(fdiro->data, fdiro->ino,
2313 				&fdiro->inode);
2314 		if (status == 0)
2315 			goto fail;
2316 	}
2317 	*len = le32_to_cpu(fdiro->inode.size);
2318 	ext4fs_file = fdiro;
2319 
2320 	return 0;
2321 fail:
2322 	ext4fs_free_node(fdiro, &ext4fs_root->diropen);
2323 
2324 	return -1;
2325 }
2326 
2327 int ext4fs_mount(unsigned part_length)
2328 {
2329 	struct ext2_data *data;
2330 	int status;
2331 	struct ext_filesystem *fs = get_fs();
2332 	data = zalloc(SUPERBLOCK_SIZE);
2333 	if (!data)
2334 		return 0;
2335 
2336 	/* Read the superblock. */
2337 	status = ext4_read_superblock((char *)&data->sblock);
2338 
2339 	if (status == 0)
2340 		goto fail;
2341 
2342 	/* Make sure this is an ext2 filesystem. */
2343 	if (le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
2344 		goto fail_noerr;
2345 
2346 
2347 	if (le32_to_cpu(data->sblock.revision_level) == 0) {
2348 		fs->inodesz = 128;
2349 		fs->gdsize = 32;
2350 	} else {
2351 		debug("EXT4 features COMPAT: %08x INCOMPAT: %08x RO_COMPAT: %08x\n",
2352 		      __le32_to_cpu(data->sblock.feature_compatibility),
2353 		      __le32_to_cpu(data->sblock.feature_incompat),
2354 		      __le32_to_cpu(data->sblock.feature_ro_compat));
2355 
2356 		fs->inodesz = le16_to_cpu(data->sblock.inode_size);
2357 		fs->gdsize = le32_to_cpu(data->sblock.feature_incompat) &
2358 			EXT4_FEATURE_INCOMPAT_64BIT ?
2359 			le16_to_cpu(data->sblock.descriptor_size) : 32;
2360 	}
2361 
2362 	debug("EXT2 rev %d, inode_size %d, descriptor size %d\n",
2363 	      le32_to_cpu(data->sblock.revision_level),
2364 	      fs->inodesz, fs->gdsize);
2365 
2366 	data->diropen.data = data;
2367 	data->diropen.ino = 2;
2368 	data->diropen.inode_read = 1;
2369 	data->inode = &data->diropen.inode;
2370 
2371 	status = ext4fs_read_inode(data, 2, data->inode);
2372 	if (status == 0)
2373 		goto fail;
2374 
2375 	ext4fs_root = data;
2376 
2377 	return 1;
2378 fail:
2379 	printf("Failed to mount ext2 filesystem...\n");
2380 fail_noerr:
2381 	free(data);
2382 	ext4fs_root = NULL;
2383 
2384 	return 0;
2385 }
2386