xref: /openbmc/u-boot/fs/ext4/ext4_common.c (revision a321abd54fa025114df2002b33ea17adc6b998b7)
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 static inline void ext4fs_sb_free_inodes_dec(struct ext2_sblock *sb)
51 {
52 	sb->free_inodes = cpu_to_le32(le32_to_cpu(sb->free_inodes) - 1);
53 }
54 
55 static inline void ext4fs_sb_free_blocks_dec(struct ext2_sblock *sb)
56 {
57 	sb->free_blocks = cpu_to_le32(le32_to_cpu(sb->free_blocks) - 1);
58 }
59 
60 static inline void ext4fs_bg_free_inodes_dec(struct ext2_block_group *bg)
61 {
62 	bg->free_inodes = cpu_to_le16(le16_to_cpu(bg->free_inodes) - 1);
63 }
64 
65 static inline void ext4fs_bg_free_blocks_dec(struct ext2_block_group *bg)
66 {
67 	bg->free_blocks = cpu_to_le16(le16_to_cpu(bg->free_blocks) - 1);
68 }
69 
70 static inline void ext4fs_bg_itable_unused_dec(struct ext2_block_group *bg)
71 {
72 	bg->bg_itable_unused = cpu_to_le16(le16_to_cpu(bg->bg_itable_unused) - 1);
73 }
74 
75 uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n)
76 {
77 	uint32_t res = size / n;
78 	if (res * n != size)
79 		res++;
80 
81 	return res;
82 }
83 
84 void put_ext4(uint64_t off, void *buf, uint32_t size)
85 {
86 	uint64_t startblock;
87 	uint64_t remainder;
88 	unsigned char *temp_ptr = NULL;
89 	struct ext_filesystem *fs = get_fs();
90 	int log2blksz = fs->dev_desc->log2blksz;
91 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, sec_buf, fs->dev_desc->blksz);
92 
93 	startblock = off >> log2blksz;
94 	startblock += part_offset;
95 	remainder = off & (uint64_t)(fs->dev_desc->blksz - 1);
96 
97 	if (fs->dev_desc == NULL)
98 		return;
99 
100 	if ((startblock + (size >> log2blksz)) >
101 	    (part_offset + fs->total_sect)) {
102 		printf("part_offset is " LBAFU "\n", part_offset);
103 		printf("total_sector is %" PRIu64 "\n", fs->total_sect);
104 		printf("error: overflow occurs\n");
105 		return;
106 	}
107 
108 	if (remainder) {
109 		blk_dread(fs->dev_desc, startblock, 1, sec_buf);
110 		temp_ptr = sec_buf;
111 		memcpy((temp_ptr + remainder), (unsigned char *)buf, size);
112 		blk_dwrite(fs->dev_desc, startblock, 1, sec_buf);
113 	} else {
114 		if (size >> log2blksz != 0) {
115 			blk_dwrite(fs->dev_desc, startblock, size >> log2blksz,
116 				   (unsigned long *)buf);
117 		} else {
118 			blk_dread(fs->dev_desc, startblock, 1, sec_buf);
119 			temp_ptr = sec_buf;
120 			memcpy(temp_ptr, buf, size);
121 			blk_dwrite(fs->dev_desc, startblock, 1,
122 				   (unsigned long *)sec_buf);
123 		}
124 	}
125 }
126 
127 static int _get_new_inode_no(unsigned char *buffer)
128 {
129 	struct ext_filesystem *fs = get_fs();
130 	unsigned char input;
131 	int operand, status;
132 	int count = 1;
133 	int j = 0;
134 
135 	/* get the blocksize of the filesystem */
136 	unsigned char *ptr = buffer;
137 	while (*ptr == 255) {
138 		ptr++;
139 		count += 8;
140 		if (count > le32_to_cpu(ext4fs_root->sblock.inodes_per_group))
141 			return -1;
142 	}
143 
144 	for (j = 0; j < fs->blksz; j++) {
145 		input = *ptr;
146 		int i = 0;
147 		while (i <= 7) {
148 			operand = 1 << i;
149 			status = input & operand;
150 			if (status) {
151 				i++;
152 				count++;
153 			} else {
154 				*ptr |= operand;
155 				return count;
156 			}
157 		}
158 		ptr = ptr + 1;
159 	}
160 
161 	return -1;
162 }
163 
164 static int _get_new_blk_no(unsigned char *buffer)
165 {
166 	unsigned char input;
167 	int operand, status;
168 	int count = 0;
169 	int j = 0;
170 	unsigned char *ptr = buffer;
171 	struct ext_filesystem *fs = get_fs();
172 
173 	if (fs->blksz != 1024)
174 		count = 0;
175 	else
176 		count = 1;
177 
178 	while (*ptr == 255) {
179 		ptr++;
180 		count += 8;
181 		if (count == (fs->blksz * 8))
182 			return -1;
183 	}
184 
185 	for (j = 0; j < fs->blksz; j++) {
186 		input = *ptr;
187 		int i = 0;
188 		while (i <= 7) {
189 			operand = 1 << i;
190 			status = input & operand;
191 			if (status) {
192 				i++;
193 				count++;
194 			} else {
195 				*ptr |= operand;
196 				return count;
197 			}
198 		}
199 		ptr = ptr + 1;
200 	}
201 
202 	return -1;
203 }
204 
205 int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index)
206 {
207 	int i, remainder, status;
208 	unsigned char *ptr = buffer;
209 	unsigned char operand;
210 	i = blockno / 8;
211 	remainder = blockno % 8;
212 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
213 
214 	i = i - (index * blocksize);
215 	if (blocksize != 1024) {
216 		ptr = ptr + i;
217 		operand = 1 << remainder;
218 		status = *ptr & operand;
219 		if (status)
220 			return -1;
221 
222 		*ptr = *ptr | operand;
223 		return 0;
224 	} else {
225 		if (remainder == 0) {
226 			ptr = ptr + i - 1;
227 			operand = (1 << 7);
228 		} else {
229 			ptr = ptr + i;
230 			operand = (1 << (remainder - 1));
231 		}
232 		status = *ptr & operand;
233 		if (status)
234 			return -1;
235 
236 		*ptr = *ptr | operand;
237 		return 0;
238 	}
239 }
240 
241 void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index)
242 {
243 	int i, remainder, status;
244 	unsigned char *ptr = buffer;
245 	unsigned char operand;
246 	i = blockno / 8;
247 	remainder = blockno % 8;
248 	int blocksize = EXT2_BLOCK_SIZE(ext4fs_root);
249 
250 	i = i - (index * blocksize);
251 	if (blocksize != 1024) {
252 		ptr = ptr + i;
253 		operand = (1 << remainder);
254 		status = *ptr & operand;
255 		if (status)
256 			*ptr = *ptr & ~(operand);
257 	} else {
258 		if (remainder == 0) {
259 			ptr = ptr + i - 1;
260 			operand = (1 << 7);
261 		} else {
262 			ptr = ptr + i;
263 			operand = (1 << (remainder - 1));
264 		}
265 		status = *ptr & operand;
266 		if (status)
267 			*ptr = *ptr & ~(operand);
268 	}
269 }
270 
271 int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index)
272 {
273 	int i, remainder, status;
274 	unsigned char *ptr = buffer;
275 	unsigned char operand;
276 
277 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
278 	i = inode_no / 8;
279 	remainder = inode_no % 8;
280 	if (remainder == 0) {
281 		ptr = ptr + i - 1;
282 		operand = (1 << 7);
283 	} else {
284 		ptr = ptr + i;
285 		operand = (1 << (remainder - 1));
286 	}
287 	status = *ptr & operand;
288 	if (status)
289 		return -1;
290 
291 	*ptr = *ptr | operand;
292 
293 	return 0;
294 }
295 
296 void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index)
297 {
298 	int i, remainder, status;
299 	unsigned char *ptr = buffer;
300 	unsigned char operand;
301 
302 	inode_no -= (index * le32_to_cpu(ext4fs_root->sblock.inodes_per_group));
303 	i = inode_no / 8;
304 	remainder = inode_no % 8;
305 	if (remainder == 0) {
306 		ptr = ptr + i - 1;
307 		operand = (1 << 7);
308 	} else {
309 		ptr = ptr + i;
310 		operand = (1 << (remainder - 1));
311 	}
312 	status = *ptr & operand;
313 	if (status)
314 		*ptr = *ptr & ~(operand);
315 }
316 
317 uint16_t ext4fs_checksum_update(uint32_t i)
318 {
319 	struct ext2_block_group *desc;
320 	struct ext_filesystem *fs = get_fs();
321 	uint16_t crc = 0;
322 	__le32 le32_i = cpu_to_le32(i);
323 
324 	desc = (struct ext2_block_group *)&fs->bgd[i];
325 	if (le32_to_cpu(fs->sb->feature_ro_compat) & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
326 		int offset = offsetof(struct ext2_block_group, bg_checksum);
327 
328 		crc = ext2fs_crc16(~0, fs->sb->unique_id,
329 				   sizeof(fs->sb->unique_id));
330 		crc = ext2fs_crc16(crc, &le32_i, sizeof(le32_i));
331 		crc = ext2fs_crc16(crc, desc, offset);
332 		offset += sizeof(desc->bg_checksum);	/* skip checksum */
333 		assert(offset == sizeof(*desc));
334 	}
335 
336 	return crc;
337 }
338 
339 static int check_void_in_dentry(struct ext2_dirent *dir, char *filename)
340 {
341 	int dentry_length;
342 	int sizeof_void_space;
343 	int new_entry_byte_reqd;
344 	short padding_factor = 0;
345 
346 	if (dir->namelen % 4 != 0)
347 		padding_factor = 4 - (dir->namelen % 4);
348 
349 	dentry_length = sizeof(struct ext2_dirent) +
350 			dir->namelen + padding_factor;
351 	sizeof_void_space = le16_to_cpu(dir->direntlen) - dentry_length;
352 	if (sizeof_void_space == 0)
353 		return 0;
354 
355 	padding_factor = 0;
356 	if (strlen(filename) % 4 != 0)
357 		padding_factor = 4 - (strlen(filename) % 4);
358 
359 	new_entry_byte_reqd = strlen(filename) +
360 	    sizeof(struct ext2_dirent) + padding_factor;
361 	if (sizeof_void_space >= new_entry_byte_reqd) {
362 		dir->direntlen = cpu_to_le16(dentry_length);
363 		return sizeof_void_space;
364 	}
365 
366 	return 0;
367 }
368 
369 int ext4fs_update_parent_dentry(char *filename, int file_type)
370 {
371 	unsigned int *zero_buffer = NULL;
372 	char *root_first_block_buffer = NULL;
373 	int blk_idx;
374 	long int first_block_no_of_root = 0;
375 	int totalbytes = 0;
376 	unsigned int new_entry_byte_reqd;
377 	int sizeof_void_space = 0;
378 	int templength = 0;
379 	int inodeno = -1;
380 	int status;
381 	struct ext_filesystem *fs = get_fs();
382 	/* directory entry */
383 	struct ext2_dirent *dir;
384 	char *temp_dir = NULL;
385 	uint32_t new_blk_no;
386 	uint32_t new_size;
387 	uint32_t new_blockcnt;
388 	uint32_t directory_blocks;
389 
390 	zero_buffer = zalloc(fs->blksz);
391 	if (!zero_buffer) {
392 		printf("No Memory\n");
393 		return -1;
394 	}
395 	root_first_block_buffer = zalloc(fs->blksz);
396 	if (!root_first_block_buffer) {
397 		free(zero_buffer);
398 		printf("No Memory\n");
399 		return -1;
400 	}
401 	new_entry_byte_reqd = ROUND(strlen(filename) +
402 				    sizeof(struct ext2_dirent), 4);
403 restart:
404 	directory_blocks = le32_to_cpu(g_parent_inode->size) >>
405 		LOG2_BLOCK_SIZE(ext4fs_root);
406 	blk_idx = directory_blocks - 1;
407 
408 restart_read:
409 	/* read the block no allocated to a file */
410 	first_block_no_of_root = read_allocated_block(g_parent_inode, blk_idx);
411 	if (first_block_no_of_root <= 0)
412 		goto fail;
413 
414 	status = ext4fs_devread((lbaint_t)first_block_no_of_root
415 				* fs->sect_perblk,
416 				0, fs->blksz, root_first_block_buffer);
417 	if (status == 0)
418 		goto fail;
419 
420 	if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root))
421 		goto fail;
422 	dir = (struct ext2_dirent *)root_first_block_buffer;
423 	totalbytes = 0;
424 
425 	while (le16_to_cpu(dir->direntlen) > 0) {
426 		unsigned short used_len = ROUND(dir->namelen +
427 		    sizeof(struct ext2_dirent), 4);
428 
429 		/* last entry of block */
430 		if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen)) {
431 
432 			/* check if new entry fits */
433 			if ((used_len + new_entry_byte_reqd) <=
434 			    le16_to_cpu(dir->direntlen)) {
435 				dir->direntlen = cpu_to_le16(used_len);
436 				break;
437 			} else {
438 				if (blk_idx > 0) {
439 					printf("Block full, trying previous\n");
440 					blk_idx--;
441 					goto restart_read;
442 				}
443 				printf("All blocks full: Allocate new\n");
444 
445 				if (le32_to_cpu(g_parent_inode->flags) &
446 						EXT4_EXTENTS_FL) {
447 					printf("Directory uses extents\n");
448 					goto fail;
449 				}
450 				if (directory_blocks >= INDIRECT_BLOCKS) {
451 					printf("Directory exceeds limit\n");
452 					goto fail;
453 				}
454 				new_blk_no = ext4fs_get_new_blk_no();
455 				if (new_blk_no == -1) {
456 					printf("no block left to assign\n");
457 					goto fail;
458 				}
459 				put_ext4((uint64_t)new_blk_no * fs->blksz, zero_buffer, fs->blksz);
460 				g_parent_inode->b.blocks.
461 					dir_blocks[directory_blocks] =
462 					cpu_to_le32(new_blk_no);
463 
464 				new_size = le32_to_cpu(g_parent_inode->size);
465 				new_size += fs->blksz;
466 				g_parent_inode->size = cpu_to_le32(new_size);
467 
468 				new_blockcnt = le32_to_cpu(g_parent_inode->blockcnt);
469 				new_blockcnt += fs->sect_perblk;
470 				g_parent_inode->blockcnt = cpu_to_le32(new_blockcnt);
471 
472 				if (ext4fs_put_metadata
473 				    (root_first_block_buffer,
474 				     first_block_no_of_root))
475 					goto fail;
476 				goto restart;
477 			}
478 		}
479 
480 		templength = le16_to_cpu(dir->direntlen);
481 		totalbytes = totalbytes + templength;
482 		sizeof_void_space = check_void_in_dentry(dir, filename);
483 		if (sizeof_void_space)
484 			break;
485 
486 		dir = (struct ext2_dirent *)((char *)dir + templength);
487 	}
488 
489 	/* make a pointer ready for creating next directory entry */
490 	templength = le16_to_cpu(dir->direntlen);
491 	totalbytes = totalbytes + templength;
492 	dir = (struct ext2_dirent *)((char *)dir + templength);
493 
494 	/* get the next available inode number */
495 	inodeno = ext4fs_get_new_inode_no();
496 	if (inodeno == -1) {
497 		printf("no inode left to assign\n");
498 		goto fail;
499 	}
500 	dir->inode = cpu_to_le32(inodeno);
501 	if (sizeof_void_space)
502 		dir->direntlen = cpu_to_le16(sizeof_void_space);
503 	else
504 		dir->direntlen = cpu_to_le16(fs->blksz - totalbytes);
505 
506 	dir->namelen = strlen(filename);
507 	dir->filetype = FILETYPE_REG;	/* regular file */
508 	temp_dir = (char *)dir;
509 	temp_dir = temp_dir + sizeof(struct ext2_dirent);
510 	memcpy(temp_dir, filename, strlen(filename));
511 
512 	/* update or write  the 1st block of root inode */
513 	if (ext4fs_put_metadata(root_first_block_buffer,
514 				first_block_no_of_root))
515 		goto fail;
516 
517 fail:
518 	free(zero_buffer);
519 	free(root_first_block_buffer);
520 
521 	return inodeno;
522 }
523 
524 static int search_dir(struct ext2_inode *parent_inode, char *dirname)
525 {
526 	int status;
527 	int inodeno = 0;
528 	int totalbytes;
529 	int templength;
530 	int direct_blk_idx;
531 	long int blknr;
532 	char *ptr = NULL;
533 	unsigned char *block_buffer = NULL;
534 	struct ext2_dirent *dir = NULL;
535 	struct ext_filesystem *fs = get_fs();
536 
537 	/* read the block no allocated to a file */
538 	for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS;
539 		direct_blk_idx++) {
540 		blknr = read_allocated_block(parent_inode, direct_blk_idx);
541 		if (blknr == 0)
542 			goto fail;
543 
544 		/* read the blocks of parent inode */
545 		block_buffer = zalloc(fs->blksz);
546 		if (!block_buffer)
547 			goto fail;
548 
549 		status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk,
550 					0, fs->blksz, (char *)block_buffer);
551 		if (status == 0)
552 			goto fail;
553 
554 		dir = (struct ext2_dirent *)block_buffer;
555 		ptr = (char *)dir;
556 		totalbytes = 0;
557 		while (le16_to_cpu(dir->direntlen) >= 0) {
558 			/*
559 			 * blocksize-totalbytes because last directory
560 			 * length i.e.,*dir->direntlen is free availble
561 			 * space in the block that means
562 			 * it is a last entry of directory entry
563 			 */
564 			if (dir->inode && (strlen(dirname) == dir->namelen)) {
565 				if (strncmp(dirname, ptr + sizeof(struct ext2_dirent), dir->namelen) == 0) {
566 					inodeno = le32_to_cpu(dir->inode);
567 					break;
568 				}
569 			}
570 
571 			if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen))
572 				break;
573 
574 			/* traversing the each directory entry */
575 			templength = le16_to_cpu(dir->direntlen);
576 			totalbytes = totalbytes + templength;
577 			dir = (struct ext2_dirent *)((char *)dir + templength);
578 			ptr = (char *)dir;
579 		}
580 
581 		free(block_buffer);
582 		block_buffer = NULL;
583 
584 		if (inodeno > 0)
585 			return inodeno;
586 	}
587 
588 fail:
589 	free(block_buffer);
590 
591 	return -1;
592 }
593 
594 static int find_dir_depth(char *dirname)
595 {
596 	char *token = strtok(dirname, "/");
597 	int count = 0;
598 	while (token != NULL) {
599 		token = strtok(NULL, "/");
600 		count++;
601 	}
602 	return count + 1 + 1;
603 	/*
604 	 * for example  for string /home/temp
605 	 * depth=home(1)+temp(1)+1 extra for NULL;
606 	 * so count is 4;
607 	 */
608 }
609 
610 static int parse_path(char **arr, char *dirname)
611 {
612 	char *token = strtok(dirname, "/");
613 	int i = 0;
614 
615 	/* add root */
616 	arr[i] = zalloc(strlen("/") + 1);
617 	if (!arr[i])
618 		return -ENOMEM;
619 	memcpy(arr[i++], "/", strlen("/"));
620 
621 	/* add each path entry after root */
622 	while (token != NULL) {
623 		arr[i] = zalloc(strlen(token) + 1);
624 		if (!arr[i])
625 			return -ENOMEM;
626 		memcpy(arr[i++], token, strlen(token));
627 		token = strtok(NULL, "/");
628 	}
629 	arr[i] = NULL;
630 
631 	return 0;
632 }
633 
634 int ext4fs_iget(int inode_no, struct ext2_inode *inode)
635 {
636 	if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0)
637 		return -1;
638 
639 	return 0;
640 }
641 
642 /*
643  * Function: ext4fs_get_parent_inode_num
644  * Return Value: inode Number of the parent directory of  file/Directory to be
645  * created
646  * dirname : Input parmater, input path name of the file/directory to be created
647  * dname : Output parameter, to be filled with the name of the directory
648  * extracted from dirname
649  */
650 int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags)
651 {
652 	int i;
653 	int depth = 0;
654 	int matched_inode_no;
655 	int result_inode_no = -1;
656 	char **ptr = NULL;
657 	char *depth_dirname = NULL;
658 	char *parse_dirname = NULL;
659 	struct ext2_inode *parent_inode = NULL;
660 	struct ext2_inode *first_inode = NULL;
661 	struct ext2_inode temp_inode;
662 
663 	if (*dirname != '/') {
664 		printf("Please supply Absolute path\n");
665 		return -1;
666 	}
667 
668 	/* TODO: input validation make equivalent to linux */
669 	depth_dirname = zalloc(strlen(dirname) + 1);
670 	if (!depth_dirname)
671 		return -ENOMEM;
672 
673 	memcpy(depth_dirname, dirname, strlen(dirname));
674 	depth = find_dir_depth(depth_dirname);
675 	parse_dirname = zalloc(strlen(dirname) + 1);
676 	if (!parse_dirname)
677 		goto fail;
678 	memcpy(parse_dirname, dirname, strlen(dirname));
679 
680 	/* allocate memory for each directory level */
681 	ptr = zalloc((depth) * sizeof(char *));
682 	if (!ptr)
683 		goto fail;
684 	if (parse_path(ptr, parse_dirname))
685 		goto fail;
686 	parent_inode = zalloc(sizeof(struct ext2_inode));
687 	if (!parent_inode)
688 		goto fail;
689 	first_inode = zalloc(sizeof(struct ext2_inode));
690 	if (!first_inode)
691 		goto fail;
692 	memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode));
693 	memcpy(first_inode, parent_inode, sizeof(struct ext2_inode));
694 	if (flags & F_FILE)
695 		result_inode_no = EXT2_ROOT_INO;
696 	for (i = 1; i < depth; i++) {
697 		matched_inode_no = search_dir(parent_inode, ptr[i]);
698 		if (matched_inode_no == -1) {
699 			if (ptr[i + 1] == NULL && i == 1) {
700 				result_inode_no = EXT2_ROOT_INO;
701 				goto end;
702 			} else {
703 				if (ptr[i + 1] == NULL)
704 					break;
705 				printf("Invalid path\n");
706 				result_inode_no = -1;
707 				goto fail;
708 			}
709 		} else {
710 			if (ptr[i + 1] != NULL) {
711 				memset(parent_inode, '\0',
712 				       sizeof(struct ext2_inode));
713 				if (ext4fs_iget(matched_inode_no,
714 						parent_inode)) {
715 					result_inode_no = -1;
716 					goto fail;
717 				}
718 				result_inode_no = matched_inode_no;
719 			} else {
720 				break;
721 			}
722 		}
723 	}
724 
725 end:
726 	if (i == 1)
727 		matched_inode_no = search_dir(first_inode, ptr[i]);
728 	else
729 		matched_inode_no = search_dir(parent_inode, ptr[i]);
730 
731 	if (matched_inode_no != -1) {
732 		ext4fs_iget(matched_inode_no, &temp_inode);
733 		if (le16_to_cpu(temp_inode.mode) & S_IFDIR) {
734 			printf("It is a Directory\n");
735 			result_inode_no = -1;
736 			goto fail;
737 		}
738 	}
739 
740 	if (strlen(ptr[i]) > 256) {
741 		result_inode_no = -1;
742 		goto fail;
743 	}
744 	memcpy(dname, ptr[i], strlen(ptr[i]));
745 
746 fail:
747 	free(depth_dirname);
748 	free(parse_dirname);
749 	for (i = 0; i < depth; i++) {
750 		if (!ptr[i])
751 			break;
752 		free(ptr[i]);
753 	}
754 	free(ptr);
755 	free(parent_inode);
756 	free(first_inode);
757 
758 	return result_inode_no;
759 }
760 
761 static int unlink_filename(char *filename, unsigned int blknr)
762 {
763 	int totalbytes = 0;
764 	int templength = 0;
765 	int status, inodeno;
766 	int found = 0;
767 	char *root_first_block_buffer = NULL;
768 	struct ext2_dirent *dir = NULL;
769 	struct ext2_dirent *previous_dir = NULL;
770 	char *ptr = NULL;
771 	struct ext_filesystem *fs = get_fs();
772 	int ret = -1;
773 
774 	/* get the first block of root */
775 	root_first_block_buffer = zalloc(fs->blksz);
776 	if (!root_first_block_buffer)
777 		return -ENOMEM;
778 	status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0,
779 				fs->blksz, root_first_block_buffer);
780 	if (status == 0)
781 		goto fail;
782 
783 	if (ext4fs_log_journal(root_first_block_buffer, blknr))
784 		goto fail;
785 	dir = (struct ext2_dirent *)root_first_block_buffer;
786 	ptr = (char *)dir;
787 	totalbytes = 0;
788 	while (le16_to_cpu(dir->direntlen) >= 0) {
789 		/*
790 		 * blocksize-totalbytes because last
791 		 * directory length i.e., *dir->direntlen
792 		 * is free availble space in the block that
793 		 * means it is a last entry of directory entry
794 		 */
795 		if (dir->inode && (strlen(filename) == dir->namelen) &&
796 		    (strncmp(ptr + sizeof(struct ext2_dirent),
797 			     filename, dir->namelen) == 0)) {
798 			printf("file found, deleting\n");
799 			inodeno = le32_to_cpu(dir->inode);
800 			if (previous_dir) {
801 				uint16_t new_len;
802 				new_len = le16_to_cpu(previous_dir->direntlen);
803 				new_len += le16_to_cpu(dir->direntlen);
804 				previous_dir->direntlen = cpu_to_le16(new_len);
805 			} else {
806 				dir->inode = 0;
807 			}
808 			found = 1;
809 			break;
810 		}
811 
812 		if (fs->blksz - totalbytes == le16_to_cpu(dir->direntlen))
813 			break;
814 
815 		/* traversing the each directory entry */
816 		templength = le16_to_cpu(dir->direntlen);
817 		totalbytes = totalbytes + templength;
818 		previous_dir = dir;
819 		dir = (struct ext2_dirent *)((char *)dir + templength);
820 		ptr = (char *)dir;
821 	}
822 
823 
824 	if (found == 1) {
825 		if (ext4fs_put_metadata(root_first_block_buffer, blknr))
826 			goto fail;
827 		ret = inodeno;
828 	}
829 fail:
830 	free(root_first_block_buffer);
831 
832 	return ret;
833 }
834 
835 int ext4fs_filename_unlink(char *filename)
836 {
837 	short direct_blk_idx = 0;
838 	long int blknr = -1;
839 	int inodeno = -1;
840 
841 	/* read the block no allocated to a file */
842 	for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS;
843 		direct_blk_idx++) {
844 		blknr = read_allocated_block(g_parent_inode, direct_blk_idx);
845 		if (blknr == 0)
846 			break;
847 		inodeno = unlink_filename(filename, blknr);
848 		if (inodeno != -1)
849 			return inodeno;
850 	}
851 
852 	return -1;
853 }
854 
855 uint32_t ext4fs_get_new_blk_no(void)
856 {
857 	short i;
858 	short status;
859 	int remainder;
860 	unsigned int bg_idx;
861 	static int prev_bg_bitmap_index = -1;
862 	unsigned int blk_per_grp = le32_to_cpu(ext4fs_root->sblock.blocks_per_group);
863 	struct ext_filesystem *fs = get_fs();
864 	char *journal_buffer = zalloc(fs->blksz);
865 	char *zero_buffer = zalloc(fs->blksz);
866 	if (!journal_buffer || !zero_buffer)
867 		goto fail;
868 	struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable;
869 
870 	if (fs->first_pass_bbmap == 0) {
871 		for (i = 0; i < fs->no_blkgrp; i++) {
872 			if (le16_to_cpu(bgd[i].free_blocks)) {
873 				if (le16_to_cpu(bgd[i].bg_flags) & EXT4_BG_BLOCK_UNINIT) {
874 					uint16_t new_flags;
875 					put_ext4((uint64_t)le32_to_cpu(bgd[i].block_id) * fs->blksz,
876 						 zero_buffer, fs->blksz);
877 					new_flags = le16_to_cpu(bgd[i].bg_flags) & ~EXT4_BG_BLOCK_UNINIT;
878 					bgd[i].bg_flags = cpu_to_le16(new_flags);
879 					memcpy(fs->blk_bmaps[i], zero_buffer,
880 					       fs->blksz);
881 				}
882 				fs->curr_blkno =
883 				    _get_new_blk_no(fs->blk_bmaps[i]);
884 				if (fs->curr_blkno == -1)
885 					/* if block bitmap is completely fill */
886 					continue;
887 				fs->curr_blkno = fs->curr_blkno +
888 						(i * fs->blksz * 8);
889 				fs->first_pass_bbmap++;
890 				ext4fs_bg_free_blocks_dec(&bgd[i]);
891 				ext4fs_sb_free_blocks_dec(fs->sb);
892 				status = ext4fs_devread(
893 							(lbaint_t)le32_to_cpu(bgd[i].block_id) *
894 							fs->sect_perblk, 0,
895 							fs->blksz,
896 							journal_buffer);
897 				if (status == 0)
898 					goto fail;
899 				if (ext4fs_log_journal(journal_buffer,
900 							le32_to_cpu(bgd[i].block_id)))
901 					goto fail;
902 				goto success;
903 			} else {
904 				debug("no space left on block group %d\n", i);
905 			}
906 		}
907 
908 		goto fail;
909 	} else {
910 restart:
911 		fs->curr_blkno++;
912 		/* get the blockbitmap index respective to blockno */
913 		bg_idx = fs->curr_blkno / blk_per_grp;
914 		if (fs->blksz == 1024) {
915 			remainder = fs->curr_blkno % blk_per_grp;
916 			if (!remainder)
917 				bg_idx--;
918 		}
919 
920 		/*
921 		 * To skip completely filled block group bitmaps
922 		 * Optimize the block allocation
923 		 */
924 		if (bg_idx >= fs->no_blkgrp)
925 			goto fail;
926 
927 		if (bgd[bg_idx].free_blocks == 0) {
928 			debug("block group %u is full. Skipping\n", bg_idx);
929 			fs->curr_blkno = fs->curr_blkno + blk_per_grp;
930 			fs->curr_blkno--;
931 			goto restart;
932 		}
933 
934 		if (le16_to_cpu(bgd[bg_idx].bg_flags) & EXT4_BG_BLOCK_UNINIT) {
935 			uint16_t new_flags;
936 			memset(zero_buffer, '\0', fs->blksz);
937 			put_ext4((uint64_t)le32_to_cpu(bgd[bg_idx].block_id) * fs->blksz,
938 				 zero_buffer, fs->blksz);
939 			memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz);
940 			new_flags = le16_to_cpu(bgd[bg_idx].bg_flags) & ~EXT4_BG_BLOCK_UNINIT;
941 			bgd[bg_idx].bg_flags = cpu_to_le16(new_flags);
942 		}
943 
944 		if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx],
945 				   bg_idx) != 0) {
946 			debug("going for restart for the block no %ld %u\n",
947 			      fs->curr_blkno, bg_idx);
948 			goto restart;
949 		}
950 
951 		/* journal backup */
952 		if (prev_bg_bitmap_index != bg_idx) {
953 			memset(journal_buffer, '\0', fs->blksz);
954 			status = ext4fs_devread(
955 						(lbaint_t)le32_to_cpu(bgd[bg_idx].block_id)
956 						* fs->sect_perblk,
957 						0, fs->blksz, journal_buffer);
958 			if (status == 0)
959 				goto fail;
960 			if (ext4fs_log_journal(journal_buffer,
961 						le32_to_cpu(bgd[bg_idx].block_id)))
962 				goto fail;
963 
964 			prev_bg_bitmap_index = bg_idx;
965 		}
966 		ext4fs_bg_free_blocks_dec(&bgd[bg_idx]);
967 		ext4fs_sb_free_blocks_dec(fs->sb);
968 		goto success;
969 	}
970 success:
971 	free(journal_buffer);
972 	free(zero_buffer);
973 
974 	return fs->curr_blkno;
975 fail:
976 	free(journal_buffer);
977 	free(zero_buffer);
978 
979 	return -1;
980 }
981 
982 int ext4fs_get_new_inode_no(void)
983 {
984 	short i;
985 	short status;
986 	unsigned int ibmap_idx;
987 	static int prev_inode_bitmap_index = -1;
988 	unsigned int inodes_per_grp = le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
989 	struct ext_filesystem *fs = get_fs();
990 	char *journal_buffer = zalloc(fs->blksz);
991 	char *zero_buffer = zalloc(fs->blksz);
992 	if (!journal_buffer || !zero_buffer)
993 		goto fail;
994 	struct ext2_block_group *bgd = (struct ext2_block_group *)fs->gdtable;
995 
996 	if (fs->first_pass_ibmap == 0) {
997 		for (i = 0; i < fs->no_blkgrp; i++) {
998 			if (bgd[i].free_inodes) {
999 				if (bgd[i].bg_itable_unused !=
1000 						bgd[i].free_inodes)
1001 					bgd[i].bg_itable_unused =
1002 						bgd[i].free_inodes;
1003 				if (le16_to_cpu(bgd[i].bg_flags) & EXT4_BG_INODE_UNINIT) {
1004 					int new_flags;
1005 					put_ext4((uint64_t)le32_to_cpu(bgd[i].inode_id) * fs->blksz,
1006 						 zero_buffer, fs->blksz);
1007 					new_flags = le16_to_cpu(bgd[i].bg_flags) & ~EXT4_BG_INODE_UNINIT;
1008 					bgd[i].bg_flags = cpu_to_le16(new_flags);
1009 					memcpy(fs->inode_bmaps[i],
1010 					       zero_buffer, fs->blksz);
1011 				}
1012 				fs->curr_inode_no =
1013 				    _get_new_inode_no(fs->inode_bmaps[i]);
1014 				if (fs->curr_inode_no == -1)
1015 					/* if block bitmap is completely fill */
1016 					continue;
1017 				fs->curr_inode_no = fs->curr_inode_no +
1018 							(i * inodes_per_grp);
1019 				fs->first_pass_ibmap++;
1020 				ext4fs_bg_free_inodes_dec(&bgd[i]);
1021 				ext4fs_bg_itable_unused_dec(&bgd[i]);
1022 				ext4fs_sb_free_inodes_dec(fs->sb);
1023 				status = ext4fs_devread(
1024 							(lbaint_t)le32_to_cpu(bgd[i].inode_id) *
1025 							fs->sect_perblk, 0,
1026 							fs->blksz,
1027 							journal_buffer);
1028 				if (status == 0)
1029 					goto fail;
1030 				if (ext4fs_log_journal(journal_buffer,
1031 							le32_to_cpu(bgd[i].inode_id)))
1032 					goto fail;
1033 				goto success;
1034 			} else
1035 				debug("no inode left on block group %d\n", i);
1036 		}
1037 		goto fail;
1038 	} else {
1039 restart:
1040 		fs->curr_inode_no++;
1041 		/* get the blockbitmap index respective to blockno */
1042 		ibmap_idx = fs->curr_inode_no / inodes_per_grp;
1043 		if (le16_to_cpu(bgd[ibmap_idx].bg_flags) & EXT4_BG_INODE_UNINIT) {
1044 			int new_flags;
1045 			memset(zero_buffer, '\0', fs->blksz);
1046 			put_ext4((uint64_t)le32_to_cpu(bgd[ibmap_idx].inode_id) * fs->blksz,
1047 				 zero_buffer, fs->blksz);
1048 			new_flags = le16_to_cpu(bgd[ibmap_idx].bg_flags) & ~EXT4_BG_INODE_UNINIT;
1049 			bgd[ibmap_idx].bg_flags = cpu_to_le16(new_flags);
1050 			memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer,
1051 				fs->blksz);
1052 		}
1053 
1054 		if (ext4fs_set_inode_bmap(fs->curr_inode_no,
1055 					  fs->inode_bmaps[ibmap_idx],
1056 					  ibmap_idx) != 0) {
1057 			debug("going for restart for the block no %d %u\n",
1058 			      fs->curr_inode_no, ibmap_idx);
1059 			goto restart;
1060 		}
1061 
1062 		/* journal backup */
1063 		if (prev_inode_bitmap_index != ibmap_idx) {
1064 			memset(journal_buffer, '\0', fs->blksz);
1065 			status = ext4fs_devread(
1066 						(lbaint_t)le32_to_cpu(bgd[ibmap_idx].inode_id)
1067 						* fs->sect_perblk,
1068 						0, fs->blksz, journal_buffer);
1069 			if (status == 0)
1070 				goto fail;
1071 			if (ext4fs_log_journal(journal_buffer,
1072 						le32_to_cpu(bgd[ibmap_idx].inode_id)))
1073 				goto fail;
1074 			prev_inode_bitmap_index = ibmap_idx;
1075 		}
1076 		if (bgd[ibmap_idx].bg_itable_unused !=
1077 				bgd[ibmap_idx].free_inodes)
1078 			bgd[ibmap_idx].bg_itable_unused =
1079 					bgd[ibmap_idx].free_inodes;
1080 		ext4fs_bg_free_inodes_dec(&bgd[ibmap_idx]);
1081 		ext4fs_bg_itable_unused_dec(&bgd[ibmap_idx]);
1082 		ext4fs_sb_free_inodes_dec(fs->sb);
1083 		goto success;
1084 	}
1085 
1086 success:
1087 	free(journal_buffer);
1088 	free(zero_buffer);
1089 
1090 	return fs->curr_inode_no;
1091 fail:
1092 	free(journal_buffer);
1093 	free(zero_buffer);
1094 
1095 	return -1;
1096 
1097 }
1098 
1099 
1100 static void alloc_single_indirect_block(struct ext2_inode *file_inode,
1101 					unsigned int *total_remaining_blocks,
1102 					unsigned int *no_blks_reqd)
1103 {
1104 	short i;
1105 	short status;
1106 	long int actual_block_no;
1107 	long int si_blockno;
1108 	/* si :single indirect */
1109 	__le32 *si_buffer = NULL;
1110 	__le32 *si_start_addr = NULL;
1111 	struct ext_filesystem *fs = get_fs();
1112 
1113 	if (*total_remaining_blocks != 0) {
1114 		si_buffer = zalloc(fs->blksz);
1115 		if (!si_buffer) {
1116 			printf("No Memory\n");
1117 			return;
1118 		}
1119 		si_start_addr = si_buffer;
1120 		si_blockno = ext4fs_get_new_blk_no();
1121 		if (si_blockno == -1) {
1122 			printf("no block left to assign\n");
1123 			goto fail;
1124 		}
1125 		(*no_blks_reqd)++;
1126 		debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks);
1127 
1128 		status = ext4fs_devread((lbaint_t)si_blockno * fs->sect_perblk,
1129 					0, fs->blksz, (char *)si_buffer);
1130 		memset(si_buffer, '\0', fs->blksz);
1131 		if (status == 0)
1132 			goto fail;
1133 
1134 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1135 			actual_block_no = ext4fs_get_new_blk_no();
1136 			if (actual_block_no == -1) {
1137 				printf("no block left to assign\n");
1138 				goto fail;
1139 			}
1140 			*si_buffer = cpu_to_le32(actual_block_no);
1141 			debug("SIAB %u: %u\n", *si_buffer,
1142 				*total_remaining_blocks);
1143 
1144 			si_buffer++;
1145 			(*total_remaining_blocks)--;
1146 			if (*total_remaining_blocks == 0)
1147 				break;
1148 		}
1149 
1150 		/* write the block to disk */
1151 		put_ext4(((uint64_t) ((uint64_t)si_blockno * (uint64_t)fs->blksz)),
1152 			 si_start_addr, fs->blksz);
1153 		file_inode->b.blocks.indir_block = cpu_to_le32(si_blockno);
1154 	}
1155 fail:
1156 	free(si_start_addr);
1157 }
1158 
1159 static void alloc_double_indirect_block(struct ext2_inode *file_inode,
1160 					unsigned int *total_remaining_blocks,
1161 					unsigned int *no_blks_reqd)
1162 {
1163 	short i;
1164 	short j;
1165 	short status;
1166 	long int actual_block_no;
1167 	/* di:double indirect */
1168 	long int di_blockno_parent;
1169 	long int di_blockno_child;
1170 	__le32 *di_parent_buffer = NULL;
1171 	__le32 *di_child_buff = NULL;
1172 	__le32 *di_block_start_addr = NULL;
1173 	__le32 *di_child_buff_start = NULL;
1174 	struct ext_filesystem *fs = get_fs();
1175 
1176 	if (*total_remaining_blocks != 0) {
1177 		/* double indirect parent block connecting to inode */
1178 		di_blockno_parent = ext4fs_get_new_blk_no();
1179 		if (di_blockno_parent == -1) {
1180 			printf("no block left to assign\n");
1181 			goto fail;
1182 		}
1183 		di_parent_buffer = zalloc(fs->blksz);
1184 		if (!di_parent_buffer)
1185 			goto fail;
1186 
1187 		di_block_start_addr = di_parent_buffer;
1188 		(*no_blks_reqd)++;
1189 		debug("DIPB %ld: %u\n", di_blockno_parent,
1190 		      *total_remaining_blocks);
1191 
1192 		status = ext4fs_devread((lbaint_t)di_blockno_parent *
1193 					fs->sect_perblk, 0,
1194 					fs->blksz, (char *)di_parent_buffer);
1195 
1196 		if (!status) {
1197 			printf("%s: Device read error!\n", __func__);
1198 			goto fail;
1199 		}
1200 		memset(di_parent_buffer, '\0', fs->blksz);
1201 
1202 		/*
1203 		 * start:for each double indirect parent
1204 		 * block create one more block
1205 		 */
1206 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1207 			di_blockno_child = ext4fs_get_new_blk_no();
1208 			if (di_blockno_child == -1) {
1209 				printf("no block left to assign\n");
1210 				goto fail;
1211 			}
1212 			di_child_buff = zalloc(fs->blksz);
1213 			if (!di_child_buff)
1214 				goto fail;
1215 
1216 			di_child_buff_start = di_child_buff;
1217 			*di_parent_buffer = cpu_to_le32(di_blockno_child);
1218 			di_parent_buffer++;
1219 			(*no_blks_reqd)++;
1220 			debug("DICB %ld: %u\n", di_blockno_child,
1221 			      *total_remaining_blocks);
1222 
1223 			status = ext4fs_devread((lbaint_t)di_blockno_child *
1224 						fs->sect_perblk, 0,
1225 						fs->blksz,
1226 						(char *)di_child_buff);
1227 
1228 			if (!status) {
1229 				printf("%s: Device read error!\n", __func__);
1230 				goto fail;
1231 			}
1232 			memset(di_child_buff, '\0', fs->blksz);
1233 			/* filling of actual datablocks for each child */
1234 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1235 				actual_block_no = ext4fs_get_new_blk_no();
1236 				if (actual_block_no == -1) {
1237 					printf("no block left to assign\n");
1238 					goto fail;
1239 				}
1240 				*di_child_buff = cpu_to_le32(actual_block_no);
1241 				debug("DIAB %ld: %u\n", actual_block_no,
1242 				      *total_remaining_blocks);
1243 
1244 				di_child_buff++;
1245 				(*total_remaining_blocks)--;
1246 				if (*total_remaining_blocks == 0)
1247 					break;
1248 			}
1249 			/* write the block  table */
1250 			put_ext4(((uint64_t) ((uint64_t)di_blockno_child * (uint64_t)fs->blksz)),
1251 				 di_child_buff_start, fs->blksz);
1252 			free(di_child_buff_start);
1253 			di_child_buff_start = NULL;
1254 
1255 			if (*total_remaining_blocks == 0)
1256 				break;
1257 		}
1258 		put_ext4(((uint64_t) ((uint64_t)di_blockno_parent * (uint64_t)fs->blksz)),
1259 			 di_block_start_addr, fs->blksz);
1260 		file_inode->b.blocks.double_indir_block = cpu_to_le32(di_blockno_parent);
1261 	}
1262 fail:
1263 	free(di_block_start_addr);
1264 }
1265 
1266 static void alloc_triple_indirect_block(struct ext2_inode *file_inode,
1267 					unsigned int *total_remaining_blocks,
1268 					unsigned int *no_blks_reqd)
1269 {
1270 	short i;
1271 	short j;
1272 	short k;
1273 	long int actual_block_no;
1274 	/* ti: Triple Indirect */
1275 	long int ti_gp_blockno;
1276 	long int ti_parent_blockno;
1277 	long int ti_child_blockno;
1278 	__le32 *ti_gp_buff = NULL;
1279 	__le32 *ti_parent_buff = NULL;
1280 	__le32 *ti_child_buff = NULL;
1281 	__le32 *ti_gp_buff_start_addr = NULL;
1282 	__le32 *ti_pbuff_start_addr = NULL;
1283 	__le32 *ti_cbuff_start_addr = NULL;
1284 	struct ext_filesystem *fs = get_fs();
1285 	if (*total_remaining_blocks != 0) {
1286 		/* triple indirect grand parent block connecting to inode */
1287 		ti_gp_blockno = ext4fs_get_new_blk_no();
1288 		if (ti_gp_blockno == -1) {
1289 			printf("no block left to assign\n");
1290 			return;
1291 		}
1292 		ti_gp_buff = zalloc(fs->blksz);
1293 		if (!ti_gp_buff)
1294 			return;
1295 
1296 		ti_gp_buff_start_addr = ti_gp_buff;
1297 		(*no_blks_reqd)++;
1298 		debug("TIGPB %ld: %u\n", ti_gp_blockno,
1299 		      *total_remaining_blocks);
1300 
1301 		/* for each 4 byte grand parent entry create one more block */
1302 		for (i = 0; i < (fs->blksz / sizeof(int)); i++) {
1303 			ti_parent_blockno = ext4fs_get_new_blk_no();
1304 			if (ti_parent_blockno == -1) {
1305 				printf("no block left to assign\n");
1306 				goto fail;
1307 			}
1308 			ti_parent_buff = zalloc(fs->blksz);
1309 			if (!ti_parent_buff)
1310 				goto fail;
1311 
1312 			ti_pbuff_start_addr = ti_parent_buff;
1313 			*ti_gp_buff = cpu_to_le32(ti_parent_blockno);
1314 			ti_gp_buff++;
1315 			(*no_blks_reqd)++;
1316 			debug("TIPB %ld: %u\n", ti_parent_blockno,
1317 			      *total_remaining_blocks);
1318 
1319 			/* for each 4 byte entry parent create one more block */
1320 			for (j = 0; j < (fs->blksz / sizeof(int)); j++) {
1321 				ti_child_blockno = ext4fs_get_new_blk_no();
1322 				if (ti_child_blockno == -1) {
1323 					printf("no block left assign\n");
1324 					goto fail1;
1325 				}
1326 				ti_child_buff = zalloc(fs->blksz);
1327 				if (!ti_child_buff)
1328 					goto fail1;
1329 
1330 				ti_cbuff_start_addr = ti_child_buff;
1331 				*ti_parent_buff = cpu_to_le32(ti_child_blockno);
1332 				ti_parent_buff++;
1333 				(*no_blks_reqd)++;
1334 				debug("TICB %ld: %u\n", ti_parent_blockno,
1335 				      *total_remaining_blocks);
1336 
1337 				/* fill actual datablocks for each child */
1338 				for (k = 0; k < (fs->blksz / sizeof(int));
1339 					k++) {
1340 					actual_block_no =
1341 					    ext4fs_get_new_blk_no();
1342 					if (actual_block_no == -1) {
1343 						printf("no block left\n");
1344 						free(ti_cbuff_start_addr);
1345 						goto fail1;
1346 					}
1347 					*ti_child_buff = cpu_to_le32(actual_block_no);
1348 					debug("TIAB %ld: %u\n", actual_block_no,
1349 					      *total_remaining_blocks);
1350 
1351 					ti_child_buff++;
1352 					(*total_remaining_blocks)--;
1353 					if (*total_remaining_blocks == 0)
1354 						break;
1355 				}
1356 				/* write the child block */
1357 				put_ext4(((uint64_t) ((uint64_t)ti_child_blockno *
1358 						      (uint64_t)fs->blksz)),
1359 					 ti_cbuff_start_addr, fs->blksz);
1360 				free(ti_cbuff_start_addr);
1361 
1362 				if (*total_remaining_blocks == 0)
1363 					break;
1364 			}
1365 			/* write the parent block */
1366 			put_ext4(((uint64_t) ((uint64_t)ti_parent_blockno * (uint64_t)fs->blksz)),
1367 				 ti_pbuff_start_addr, fs->blksz);
1368 			free(ti_pbuff_start_addr);
1369 
1370 			if (*total_remaining_blocks == 0)
1371 				break;
1372 		}
1373 		/* write the grand parent block */
1374 		put_ext4(((uint64_t) ((uint64_t)ti_gp_blockno * (uint64_t)fs->blksz)),
1375 			 ti_gp_buff_start_addr, fs->blksz);
1376 		file_inode->b.blocks.triple_indir_block = cpu_to_le32(ti_gp_blockno);
1377 		free(ti_gp_buff_start_addr);
1378 		return;
1379 	}
1380 fail1:
1381 	free(ti_pbuff_start_addr);
1382 fail:
1383 	free(ti_gp_buff_start_addr);
1384 }
1385 
1386 void ext4fs_allocate_blocks(struct ext2_inode *file_inode,
1387 				unsigned int total_remaining_blocks,
1388 				unsigned int *total_no_of_block)
1389 {
1390 	short i;
1391 	long int direct_blockno;
1392 	unsigned int no_blks_reqd = 0;
1393 
1394 	/* allocation of direct blocks */
1395 	for (i = 0; total_remaining_blocks && i < INDIRECT_BLOCKS; i++) {
1396 		direct_blockno = ext4fs_get_new_blk_no();
1397 		if (direct_blockno == -1) {
1398 			printf("no block left to assign\n");
1399 			return;
1400 		}
1401 		file_inode->b.blocks.dir_blocks[i] = cpu_to_le32(direct_blockno);
1402 		debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks);
1403 
1404 		total_remaining_blocks--;
1405 	}
1406 
1407 	alloc_single_indirect_block(file_inode, &total_remaining_blocks,
1408 				    &no_blks_reqd);
1409 	alloc_double_indirect_block(file_inode, &total_remaining_blocks,
1410 				    &no_blks_reqd);
1411 	alloc_triple_indirect_block(file_inode, &total_remaining_blocks,
1412 				    &no_blks_reqd);
1413 	*total_no_of_block += no_blks_reqd;
1414 }
1415 
1416 #endif
1417 
1418 static struct ext4_extent_header *ext4fs_get_extent_block
1419 	(struct ext2_data *data, char *buf,
1420 		struct ext4_extent_header *ext_block,
1421 		uint32_t fileblock, int log2_blksz)
1422 {
1423 	struct ext4_extent_idx *index;
1424 	unsigned long long block;
1425 	int blksz = EXT2_BLOCK_SIZE(data);
1426 	int i;
1427 
1428 	while (1) {
1429 		index = (struct ext4_extent_idx *)(ext_block + 1);
1430 
1431 		if (le16_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
1432 			return NULL;
1433 
1434 		if (ext_block->eh_depth == 0)
1435 			return ext_block;
1436 		i = -1;
1437 		do {
1438 			i++;
1439 			if (i >= le16_to_cpu(ext_block->eh_entries))
1440 				break;
1441 		} while (fileblock >= le32_to_cpu(index[i].ei_block));
1442 
1443 		if (--i < 0)
1444 			return NULL;
1445 
1446 		block = le16_to_cpu(index[i].ei_leaf_hi);
1447 		block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
1448 
1449 		if (ext4fs_devread((lbaint_t)block << log2_blksz, 0, blksz,
1450 				   buf))
1451 			ext_block = (struct ext4_extent_header *)buf;
1452 		else
1453 			return NULL;
1454 	}
1455 }
1456 
1457 static int ext4fs_blockgroup
1458 	(struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
1459 {
1460 	long int blkno;
1461 	unsigned int blkoff, desc_per_blk;
1462 	int log2blksz = get_fs()->dev_desc->log2blksz;
1463 
1464 	desc_per_blk = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group);
1465 
1466 	blkno = le32_to_cpu(data->sblock.first_data_block) + 1 +
1467 			group / desc_per_blk;
1468 	blkoff = (group % desc_per_blk) * sizeof(struct ext2_block_group);
1469 
1470 	debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
1471 	      group, blkno, blkoff);
1472 
1473 	return ext4fs_devread((lbaint_t)blkno <<
1474 			      (LOG2_BLOCK_SIZE(data) - log2blksz),
1475 			      blkoff, sizeof(struct ext2_block_group),
1476 			      (char *)blkgrp);
1477 }
1478 
1479 int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
1480 {
1481 	struct ext2_block_group blkgrp;
1482 	struct ext2_sblock *sblock = &data->sblock;
1483 	struct ext_filesystem *fs = get_fs();
1484 	int log2blksz = get_fs()->dev_desc->log2blksz;
1485 	int inodes_per_block, status;
1486 	long int blkno;
1487 	unsigned int blkoff;
1488 
1489 	/* It is easier to calculate if the first inode is 0. */
1490 	ino--;
1491 	status = ext4fs_blockgroup(data, ino / le32_to_cpu
1492 				   (sblock->inodes_per_group), &blkgrp);
1493 	if (status == 0)
1494 		return 0;
1495 
1496 	inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
1497 	blkno = le32_to_cpu(blkgrp.inode_table_id) +
1498 	    (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1499 	blkoff = (ino % inodes_per_block) * fs->inodesz;
1500 	/* Read the inode. */
1501 	status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) -
1502 				log2blksz), blkoff,
1503 				sizeof(struct ext2_inode), (char *)inode);
1504 	if (status == 0)
1505 		return 0;
1506 
1507 	return 1;
1508 }
1509 
1510 long int read_allocated_block(struct ext2_inode *inode, int fileblock)
1511 {
1512 	long int blknr;
1513 	int blksz;
1514 	int log2_blksz;
1515 	int status;
1516 	long int rblock;
1517 	long int perblock_parent;
1518 	long int perblock_child;
1519 	unsigned long long start;
1520 	/* get the blocksize of the filesystem */
1521 	blksz = EXT2_BLOCK_SIZE(ext4fs_root);
1522 	log2_blksz = LOG2_BLOCK_SIZE(ext4fs_root)
1523 		- get_fs()->dev_desc->log2blksz;
1524 
1525 	if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
1526 		char *buf = zalloc(blksz);
1527 		if (!buf)
1528 			return -ENOMEM;
1529 		struct ext4_extent_header *ext_block;
1530 		struct ext4_extent *extent;
1531 		int i = -1;
1532 		ext_block =
1533 			ext4fs_get_extent_block(ext4fs_root, buf,
1534 						(struct ext4_extent_header *)
1535 						inode->b.blocks.dir_blocks,
1536 						fileblock, log2_blksz);
1537 		if (!ext_block) {
1538 			printf("invalid extent block\n");
1539 			free(buf);
1540 			return -EINVAL;
1541 		}
1542 
1543 		extent = (struct ext4_extent *)(ext_block + 1);
1544 
1545 		do {
1546 			i++;
1547 			if (i >= le16_to_cpu(ext_block->eh_entries))
1548 				break;
1549 		} while (fileblock >= le32_to_cpu(extent[i].ee_block));
1550 		if (--i >= 0) {
1551 			fileblock -= le32_to_cpu(extent[i].ee_block);
1552 			if (fileblock >= le16_to_cpu(extent[i].ee_len)) {
1553 				free(buf);
1554 				return 0;
1555 			}
1556 
1557 			start = le16_to_cpu(extent[i].ee_start_hi);
1558 			start = (start << 32) +
1559 					le32_to_cpu(extent[i].ee_start_lo);
1560 			free(buf);
1561 			return fileblock + start;
1562 		}
1563 
1564 		printf("Extent Error\n");
1565 		free(buf);
1566 		return -1;
1567 	}
1568 
1569 	/* Direct blocks. */
1570 	if (fileblock < INDIRECT_BLOCKS)
1571 		blknr = le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
1572 
1573 	/* Indirect. */
1574 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
1575 		if (ext4fs_indir1_block == NULL) {
1576 			ext4fs_indir1_block = zalloc(blksz);
1577 			if (ext4fs_indir1_block == NULL) {
1578 				printf("** SI ext2fs read block (indir 1)"
1579 					"malloc failed. **\n");
1580 				return -1;
1581 			}
1582 			ext4fs_indir1_size = blksz;
1583 			ext4fs_indir1_blkno = -1;
1584 		}
1585 		if (blksz != ext4fs_indir1_size) {
1586 			free(ext4fs_indir1_block);
1587 			ext4fs_indir1_block = NULL;
1588 			ext4fs_indir1_size = 0;
1589 			ext4fs_indir1_blkno = -1;
1590 			ext4fs_indir1_block = zalloc(blksz);
1591 			if (ext4fs_indir1_block == NULL) {
1592 				printf("** SI ext2fs read block (indir 1):"
1593 					"malloc failed. **\n");
1594 				return -1;
1595 			}
1596 			ext4fs_indir1_size = blksz;
1597 		}
1598 		if ((le32_to_cpu(inode->b.blocks.indir_block) <<
1599 		     log2_blksz) != ext4fs_indir1_blkno) {
1600 			status =
1601 			    ext4fs_devread((lbaint_t)le32_to_cpu
1602 					   (inode->b.blocks.
1603 					    indir_block) << log2_blksz, 0,
1604 					   blksz, (char *)ext4fs_indir1_block);
1605 			if (status == 0) {
1606 				printf("** SI ext2fs read block (indir 1)"
1607 					"failed. **\n");
1608 				return 0;
1609 			}
1610 			ext4fs_indir1_blkno =
1611 				le32_to_cpu(inode->b.blocks.
1612 					       indir_block) << log2_blksz;
1613 		}
1614 		blknr = le32_to_cpu(ext4fs_indir1_block
1615 				      [fileblock - INDIRECT_BLOCKS]);
1616 	}
1617 	/* Double indirect. */
1618 	else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
1619 					(blksz / 4 + 1)))) {
1620 
1621 		long int perblock = blksz / 4;
1622 		long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
1623 
1624 		if (ext4fs_indir1_block == NULL) {
1625 			ext4fs_indir1_block = zalloc(blksz);
1626 			if (ext4fs_indir1_block == NULL) {
1627 				printf("** DI ext2fs read block (indir 2 1)"
1628 					"malloc failed. **\n");
1629 				return -1;
1630 			}
1631 			ext4fs_indir1_size = blksz;
1632 			ext4fs_indir1_blkno = -1;
1633 		}
1634 		if (blksz != ext4fs_indir1_size) {
1635 			free(ext4fs_indir1_block);
1636 			ext4fs_indir1_block = NULL;
1637 			ext4fs_indir1_size = 0;
1638 			ext4fs_indir1_blkno = -1;
1639 			ext4fs_indir1_block = zalloc(blksz);
1640 			if (ext4fs_indir1_block == NULL) {
1641 				printf("** DI ext2fs read block (indir 2 1)"
1642 					"malloc failed. **\n");
1643 				return -1;
1644 			}
1645 			ext4fs_indir1_size = blksz;
1646 		}
1647 		if ((le32_to_cpu(inode->b.blocks.double_indir_block) <<
1648 		     log2_blksz) != ext4fs_indir1_blkno) {
1649 			status =
1650 			    ext4fs_devread((lbaint_t)le32_to_cpu
1651 					   (inode->b.blocks.
1652 					    double_indir_block) << log2_blksz,
1653 					   0, blksz,
1654 					   (char *)ext4fs_indir1_block);
1655 			if (status == 0) {
1656 				printf("** DI ext2fs read block (indir 2 1)"
1657 					"failed. **\n");
1658 				return -1;
1659 			}
1660 			ext4fs_indir1_blkno =
1661 			    le32_to_cpu(inode->b.blocks.double_indir_block) <<
1662 			    log2_blksz;
1663 		}
1664 
1665 		if (ext4fs_indir2_block == NULL) {
1666 			ext4fs_indir2_block = zalloc(blksz);
1667 			if (ext4fs_indir2_block == NULL) {
1668 				printf("** DI ext2fs read block (indir 2 2)"
1669 					"malloc failed. **\n");
1670 				return -1;
1671 			}
1672 			ext4fs_indir2_size = blksz;
1673 			ext4fs_indir2_blkno = -1;
1674 		}
1675 		if (blksz != ext4fs_indir2_size) {
1676 			free(ext4fs_indir2_block);
1677 			ext4fs_indir2_block = NULL;
1678 			ext4fs_indir2_size = 0;
1679 			ext4fs_indir2_blkno = -1;
1680 			ext4fs_indir2_block = zalloc(blksz);
1681 			if (ext4fs_indir2_block == NULL) {
1682 				printf("** DI ext2fs read block (indir 2 2)"
1683 					"malloc failed. **\n");
1684 				return -1;
1685 			}
1686 			ext4fs_indir2_size = blksz;
1687 		}
1688 		if ((le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
1689 		     log2_blksz) != ext4fs_indir2_blkno) {
1690 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1691 						(ext4fs_indir1_block
1692 						 [rblock /
1693 						  perblock]) << log2_blksz, 0,
1694 						blksz,
1695 						(char *)ext4fs_indir2_block);
1696 			if (status == 0) {
1697 				printf("** DI ext2fs read block (indir 2 2)"
1698 					"failed. **\n");
1699 				return -1;
1700 			}
1701 			ext4fs_indir2_blkno =
1702 			    le32_to_cpu(ext4fs_indir1_block[rblock
1703 							      /
1704 							      perblock]) <<
1705 			    log2_blksz;
1706 		}
1707 		blknr = le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
1708 	}
1709 	/* Tripple indirect. */
1710 	else {
1711 		rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
1712 				      (blksz / 4 * blksz / 4));
1713 		perblock_child = blksz / 4;
1714 		perblock_parent = ((blksz / 4) * (blksz / 4));
1715 
1716 		if (ext4fs_indir1_block == NULL) {
1717 			ext4fs_indir1_block = zalloc(blksz);
1718 			if (ext4fs_indir1_block == NULL) {
1719 				printf("** TI ext2fs read block (indir 2 1)"
1720 					"malloc failed. **\n");
1721 				return -1;
1722 			}
1723 			ext4fs_indir1_size = blksz;
1724 			ext4fs_indir1_blkno = -1;
1725 		}
1726 		if (blksz != ext4fs_indir1_size) {
1727 			free(ext4fs_indir1_block);
1728 			ext4fs_indir1_block = NULL;
1729 			ext4fs_indir1_size = 0;
1730 			ext4fs_indir1_blkno = -1;
1731 			ext4fs_indir1_block = zalloc(blksz);
1732 			if (ext4fs_indir1_block == NULL) {
1733 				printf("** TI ext2fs read block (indir 2 1)"
1734 					"malloc failed. **\n");
1735 				return -1;
1736 			}
1737 			ext4fs_indir1_size = blksz;
1738 		}
1739 		if ((le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1740 		     log2_blksz) != ext4fs_indir1_blkno) {
1741 			status = ext4fs_devread
1742 			    ((lbaint_t)
1743 			     le32_to_cpu(inode->b.blocks.triple_indir_block)
1744 			     << log2_blksz, 0, blksz,
1745 			     (char *)ext4fs_indir1_block);
1746 			if (status == 0) {
1747 				printf("** TI ext2fs read block (indir 2 1)"
1748 					"failed. **\n");
1749 				return -1;
1750 			}
1751 			ext4fs_indir1_blkno =
1752 			    le32_to_cpu(inode->b.blocks.triple_indir_block) <<
1753 			    log2_blksz;
1754 		}
1755 
1756 		if (ext4fs_indir2_block == NULL) {
1757 			ext4fs_indir2_block = zalloc(blksz);
1758 			if (ext4fs_indir2_block == NULL) {
1759 				printf("** TI ext2fs read block (indir 2 2)"
1760 					"malloc failed. **\n");
1761 				return -1;
1762 			}
1763 			ext4fs_indir2_size = blksz;
1764 			ext4fs_indir2_blkno = -1;
1765 		}
1766 		if (blksz != ext4fs_indir2_size) {
1767 			free(ext4fs_indir2_block);
1768 			ext4fs_indir2_block = NULL;
1769 			ext4fs_indir2_size = 0;
1770 			ext4fs_indir2_blkno = -1;
1771 			ext4fs_indir2_block = zalloc(blksz);
1772 			if (ext4fs_indir2_block == NULL) {
1773 				printf("** TI ext2fs read block (indir 2 2)"
1774 					"malloc failed. **\n");
1775 				return -1;
1776 			}
1777 			ext4fs_indir2_size = blksz;
1778 		}
1779 		if ((le32_to_cpu(ext4fs_indir1_block[rblock /
1780 						       perblock_parent]) <<
1781 		     log2_blksz)
1782 		    != ext4fs_indir2_blkno) {
1783 			status = ext4fs_devread((lbaint_t)le32_to_cpu
1784 						(ext4fs_indir1_block
1785 						 [rblock /
1786 						  perblock_parent]) <<
1787 						log2_blksz, 0, blksz,
1788 						(char *)ext4fs_indir2_block);
1789 			if (status == 0) {
1790 				printf("** TI 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 							      perblock_parent])
1797 			    << log2_blksz;
1798 		}
1799 
1800 		if (ext4fs_indir3_block == NULL) {
1801 			ext4fs_indir3_block = zalloc(blksz);
1802 			if (ext4fs_indir3_block == NULL) {
1803 				printf("** TI ext2fs read block (indir 2 2)"
1804 					"malloc failed. **\n");
1805 				return -1;
1806 			}
1807 			ext4fs_indir3_size = blksz;
1808 			ext4fs_indir3_blkno = -1;
1809 		}
1810 		if (blksz != ext4fs_indir3_size) {
1811 			free(ext4fs_indir3_block);
1812 			ext4fs_indir3_block = NULL;
1813 			ext4fs_indir3_size = 0;
1814 			ext4fs_indir3_blkno = -1;
1815 			ext4fs_indir3_block = zalloc(blksz);
1816 			if (ext4fs_indir3_block == NULL) {
1817 				printf("** TI ext2fs read block (indir 2 2)"
1818 					"malloc failed. **\n");
1819 				return -1;
1820 			}
1821 			ext4fs_indir3_size = blksz;
1822 		}
1823 		if ((le32_to_cpu(ext4fs_indir2_block[rblock
1824 						       /
1825 						       perblock_child]) <<
1826 		     log2_blksz) != ext4fs_indir3_blkno) {
1827 			status =
1828 			    ext4fs_devread((lbaint_t)le32_to_cpu
1829 					   (ext4fs_indir2_block
1830 					    [(rblock / perblock_child)
1831 					     % (blksz / 4)]) << log2_blksz, 0,
1832 					   blksz, (char *)ext4fs_indir3_block);
1833 			if (status == 0) {
1834 				printf("** TI ext2fs read block (indir 2 2)"
1835 				       "failed. **\n");
1836 				return -1;
1837 			}
1838 			ext4fs_indir3_blkno =
1839 			    le32_to_cpu(ext4fs_indir2_block[(rblock /
1840 							       perblock_child) %
1841 							      (blksz /
1842 							       4)]) <<
1843 			    log2_blksz;
1844 		}
1845 
1846 		blknr = le32_to_cpu(ext4fs_indir3_block
1847 				      [rblock % perblock_child]);
1848 	}
1849 	debug("read_allocated_block %ld\n", blknr);
1850 
1851 	return blknr;
1852 }
1853 
1854 /**
1855  * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's
1856  *			    global pointers
1857  *
1858  * This function assures that for a file with the same name but different size
1859  * the sequential store on the ext4 filesystem will be correct.
1860  *
1861  * In this function the global data, responsible for internal representation
1862  * of the ext4 data are initialized to the reset state. Without this, during
1863  * replacement of the smaller file with the bigger truncation of new file was
1864  * performed.
1865  */
1866 void ext4fs_reinit_global(void)
1867 {
1868 	if (ext4fs_indir1_block != NULL) {
1869 		free(ext4fs_indir1_block);
1870 		ext4fs_indir1_block = NULL;
1871 		ext4fs_indir1_size = 0;
1872 		ext4fs_indir1_blkno = -1;
1873 	}
1874 	if (ext4fs_indir2_block != NULL) {
1875 		free(ext4fs_indir2_block);
1876 		ext4fs_indir2_block = NULL;
1877 		ext4fs_indir2_size = 0;
1878 		ext4fs_indir2_blkno = -1;
1879 	}
1880 	if (ext4fs_indir3_block != NULL) {
1881 		free(ext4fs_indir3_block);
1882 		ext4fs_indir3_block = NULL;
1883 		ext4fs_indir3_size = 0;
1884 		ext4fs_indir3_blkno = -1;
1885 	}
1886 }
1887 void ext4fs_close(void)
1888 {
1889 	if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
1890 		ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
1891 		ext4fs_file = NULL;
1892 	}
1893 	if (ext4fs_root != NULL) {
1894 		free(ext4fs_root);
1895 		ext4fs_root = NULL;
1896 	}
1897 
1898 	ext4fs_reinit_global();
1899 }
1900 
1901 int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
1902 				struct ext2fs_node **fnode, int *ftype)
1903 {
1904 	unsigned int fpos = 0;
1905 	int status;
1906 	loff_t actread;
1907 	struct ext2fs_node *diro = (struct ext2fs_node *) dir;
1908 
1909 #ifdef DEBUG
1910 	if (name != NULL)
1911 		printf("Iterate dir %s\n", name);
1912 #endif /* of DEBUG */
1913 	if (!diro->inode_read) {
1914 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
1915 		if (status == 0)
1916 			return 0;
1917 	}
1918 	/* Search the file.  */
1919 	while (fpos < le32_to_cpu(diro->inode.size)) {
1920 		struct ext2_dirent dirent;
1921 
1922 		status = ext4fs_read_file(diro, fpos,
1923 					   sizeof(struct ext2_dirent),
1924 					   (char *)&dirent, &actread);
1925 		if (status < 0)
1926 			return 0;
1927 
1928 		if (dirent.direntlen == 0) {
1929 			printf("Failed to iterate over directory %s\n", name);
1930 			return 0;
1931 		}
1932 
1933 		if (dirent.namelen != 0) {
1934 			char filename[dirent.namelen + 1];
1935 			struct ext2fs_node *fdiro;
1936 			int type = FILETYPE_UNKNOWN;
1937 
1938 			status = ext4fs_read_file(diro,
1939 						  fpos +
1940 						  sizeof(struct ext2_dirent),
1941 						  dirent.namelen, filename,
1942 						  &actread);
1943 			if (status < 0)
1944 				return 0;
1945 
1946 			fdiro = zalloc(sizeof(struct ext2fs_node));
1947 			if (!fdiro)
1948 				return 0;
1949 
1950 			fdiro->data = diro->data;
1951 			fdiro->ino = le32_to_cpu(dirent.inode);
1952 
1953 			filename[dirent.namelen] = '\0';
1954 
1955 			if (dirent.filetype != FILETYPE_UNKNOWN) {
1956 				fdiro->inode_read = 0;
1957 
1958 				if (dirent.filetype == FILETYPE_DIRECTORY)
1959 					type = FILETYPE_DIRECTORY;
1960 				else if (dirent.filetype == FILETYPE_SYMLINK)
1961 					type = FILETYPE_SYMLINK;
1962 				else if (dirent.filetype == FILETYPE_REG)
1963 					type = FILETYPE_REG;
1964 			} else {
1965 				status = ext4fs_read_inode(diro->data,
1966 							   le32_to_cpu
1967 							   (dirent.inode),
1968 							   &fdiro->inode);
1969 				if (status == 0) {
1970 					free(fdiro);
1971 					return 0;
1972 				}
1973 				fdiro->inode_read = 1;
1974 
1975 				if ((le16_to_cpu(fdiro->inode.mode) &
1976 				     FILETYPE_INO_MASK) ==
1977 				    FILETYPE_INO_DIRECTORY) {
1978 					type = FILETYPE_DIRECTORY;
1979 				} else if ((le16_to_cpu(fdiro->inode.mode)
1980 					    & FILETYPE_INO_MASK) ==
1981 					   FILETYPE_INO_SYMLINK) {
1982 					type = FILETYPE_SYMLINK;
1983 				} else if ((le16_to_cpu(fdiro->inode.mode)
1984 					    & FILETYPE_INO_MASK) ==
1985 					   FILETYPE_INO_REG) {
1986 					type = FILETYPE_REG;
1987 				}
1988 			}
1989 #ifdef DEBUG
1990 			printf("iterate >%s<\n", filename);
1991 #endif /* of DEBUG */
1992 			if ((name != NULL) && (fnode != NULL)
1993 			    && (ftype != NULL)) {
1994 				if (strcmp(filename, name) == 0) {
1995 					*ftype = type;
1996 					*fnode = fdiro;
1997 					return 1;
1998 				}
1999 			} else {
2000 				if (fdiro->inode_read == 0) {
2001 					status = ext4fs_read_inode(diro->data,
2002 								 le32_to_cpu(
2003 								 dirent.inode),
2004 								 &fdiro->inode);
2005 					if (status == 0) {
2006 						free(fdiro);
2007 						return 0;
2008 					}
2009 					fdiro->inode_read = 1;
2010 				}
2011 				switch (type) {
2012 				case FILETYPE_DIRECTORY:
2013 					printf("<DIR> ");
2014 					break;
2015 				case FILETYPE_SYMLINK:
2016 					printf("<SYM> ");
2017 					break;
2018 				case FILETYPE_REG:
2019 					printf("      ");
2020 					break;
2021 				default:
2022 					printf("< ? > ");
2023 					break;
2024 				}
2025 				printf("%10u %s\n",
2026 				       le32_to_cpu(fdiro->inode.size),
2027 					filename);
2028 			}
2029 			free(fdiro);
2030 		}
2031 		fpos += le16_to_cpu(dirent.direntlen);
2032 	}
2033 	return 0;
2034 }
2035 
2036 static char *ext4fs_read_symlink(struct ext2fs_node *node)
2037 {
2038 	char *symlink;
2039 	struct ext2fs_node *diro = node;
2040 	int status;
2041 	loff_t actread;
2042 
2043 	if (!diro->inode_read) {
2044 		status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
2045 		if (status == 0)
2046 			return NULL;
2047 	}
2048 	symlink = zalloc(le32_to_cpu(diro->inode.size) + 1);
2049 	if (!symlink)
2050 		return NULL;
2051 
2052 	if (le32_to_cpu(diro->inode.size) < sizeof(diro->inode.b.symlink)) {
2053 		strncpy(symlink, diro->inode.b.symlink,
2054 			 le32_to_cpu(diro->inode.size));
2055 	} else {
2056 		status = ext4fs_read_file(diro, 0,
2057 					   le32_to_cpu(diro->inode.size),
2058 					   symlink, &actread);
2059 		if ((status < 0) || (actread == 0)) {
2060 			free(symlink);
2061 			return NULL;
2062 		}
2063 	}
2064 	symlink[le32_to_cpu(diro->inode.size)] = '\0';
2065 	return symlink;
2066 }
2067 
2068 static int ext4fs_find_file1(const char *currpath,
2069 			     struct ext2fs_node *currroot,
2070 			     struct ext2fs_node **currfound, int *foundtype)
2071 {
2072 	char fpath[strlen(currpath) + 1];
2073 	char *name = fpath;
2074 	char *next;
2075 	int status;
2076 	int type = FILETYPE_DIRECTORY;
2077 	struct ext2fs_node *currnode = currroot;
2078 	struct ext2fs_node *oldnode = currroot;
2079 
2080 	strncpy(fpath, currpath, strlen(currpath) + 1);
2081 
2082 	/* Remove all leading slashes. */
2083 	while (*name == '/')
2084 		name++;
2085 
2086 	if (!*name) {
2087 		*currfound = currnode;
2088 		return 1;
2089 	}
2090 
2091 	for (;;) {
2092 		int found;
2093 
2094 		/* Extract the actual part from the pathname. */
2095 		next = strchr(name, '/');
2096 		if (next) {
2097 			/* Remove all leading slashes. */
2098 			while (*next == '/')
2099 				*(next++) = '\0';
2100 		}
2101 
2102 		if (type != FILETYPE_DIRECTORY) {
2103 			ext4fs_free_node(currnode, currroot);
2104 			return 0;
2105 		}
2106 
2107 		oldnode = currnode;
2108 
2109 		/* Iterate over the directory. */
2110 		found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
2111 		if (found == 0)
2112 			return 0;
2113 
2114 		if (found == -1)
2115 			break;
2116 
2117 		/* Read in the symlink and follow it. */
2118 		if (type == FILETYPE_SYMLINK) {
2119 			char *symlink;
2120 
2121 			/* Test if the symlink does not loop. */
2122 			if (++symlinknest == 8) {
2123 				ext4fs_free_node(currnode, currroot);
2124 				ext4fs_free_node(oldnode, currroot);
2125 				return 0;
2126 			}
2127 
2128 			symlink = ext4fs_read_symlink(currnode);
2129 			ext4fs_free_node(currnode, currroot);
2130 
2131 			if (!symlink) {
2132 				ext4fs_free_node(oldnode, currroot);
2133 				return 0;
2134 			}
2135 
2136 			debug("Got symlink >%s<\n", symlink);
2137 
2138 			if (symlink[0] == '/') {
2139 				ext4fs_free_node(oldnode, currroot);
2140 				oldnode = &ext4fs_root->diropen;
2141 			}
2142 
2143 			/* Lookup the node the symlink points to. */
2144 			status = ext4fs_find_file1(symlink, oldnode,
2145 						    &currnode, &type);
2146 
2147 			free(symlink);
2148 
2149 			if (status == 0) {
2150 				ext4fs_free_node(oldnode, currroot);
2151 				return 0;
2152 			}
2153 		}
2154 
2155 		ext4fs_free_node(oldnode, currroot);
2156 
2157 		/* Found the node! */
2158 		if (!next || *next == '\0') {
2159 			*currfound = currnode;
2160 			*foundtype = type;
2161 			return 1;
2162 		}
2163 		name = next;
2164 	}
2165 	return -1;
2166 }
2167 
2168 int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
2169 	struct ext2fs_node **foundnode, int expecttype)
2170 {
2171 	int status;
2172 	int foundtype = FILETYPE_DIRECTORY;
2173 
2174 	symlinknest = 0;
2175 	if (!path)
2176 		return 0;
2177 
2178 	status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
2179 	if (status == 0)
2180 		return 0;
2181 
2182 	/* Check if the node that was found was of the expected type. */
2183 	if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
2184 		return 0;
2185 	else if ((expecttype == FILETYPE_DIRECTORY)
2186 		   && (foundtype != expecttype))
2187 		return 0;
2188 
2189 	return 1;
2190 }
2191 
2192 int ext4fs_open(const char *filename, loff_t *len)
2193 {
2194 	struct ext2fs_node *fdiro = NULL;
2195 	int status;
2196 
2197 	if (ext4fs_root == NULL)
2198 		return -1;
2199 
2200 	ext4fs_file = NULL;
2201 	status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
2202 				  FILETYPE_REG);
2203 	if (status == 0)
2204 		goto fail;
2205 
2206 	if (!fdiro->inode_read) {
2207 		status = ext4fs_read_inode(fdiro->data, fdiro->ino,
2208 				&fdiro->inode);
2209 		if (status == 0)
2210 			goto fail;
2211 	}
2212 	*len = le32_to_cpu(fdiro->inode.size);
2213 	ext4fs_file = fdiro;
2214 
2215 	return 0;
2216 fail:
2217 	ext4fs_free_node(fdiro, &ext4fs_root->diropen);
2218 
2219 	return -1;
2220 }
2221 
2222 int ext4fs_mount(unsigned part_length)
2223 {
2224 	struct ext2_data *data;
2225 	int status;
2226 	struct ext_filesystem *fs = get_fs();
2227 	data = zalloc(SUPERBLOCK_SIZE);
2228 	if (!data)
2229 		return 0;
2230 
2231 	/* Read the superblock. */
2232 	status = ext4_read_superblock((char *)&data->sblock);
2233 
2234 	if (status == 0)
2235 		goto fail;
2236 
2237 	/* Make sure this is an ext2 filesystem. */
2238 	if (le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
2239 		goto fail;
2240 
2241 	/*
2242 	 * The 64bit feature was enabled when metadata_csum was enabled
2243 	 * and we do not support metadata_csum (and cannot reliably find
2244 	 * files when it is set.  Refuse to mount.
2245 	 */
2246 	if (le32_to_cpu(data->sblock.feature_incompat) & EXT4_FEATURE_INCOMPAT_64BIT) {
2247 		printf("Unsupported feature found (64bit, possibly metadata_csum), not mounting\n");
2248 		goto fail;
2249 	}
2250 
2251 	if (le32_to_cpu(data->sblock.revision_level) == 0)
2252 		fs->inodesz = 128;
2253 	else
2254 		fs->inodesz = le16_to_cpu(data->sblock.inode_size);
2255 
2256 	debug("EXT2 rev %d, inode_size %d\n",
2257 	       le32_to_cpu(data->sblock.revision_level), fs->inodesz);
2258 
2259 	data->diropen.data = data;
2260 	data->diropen.ino = 2;
2261 	data->diropen.inode_read = 1;
2262 	data->inode = &data->diropen.inode;
2263 
2264 	status = ext4fs_read_inode(data, 2, data->inode);
2265 	if (status == 0)
2266 		goto fail;
2267 
2268 	ext4fs_root = data;
2269 
2270 	return 1;
2271 fail:
2272 	printf("Failed to mount ext2 filesystem...\n");
2273 	free(data);
2274 	ext4fs_root = NULL;
2275 
2276 	return 0;
2277 }
2278