xref: /openbmc/u-boot/fs/ext4/ext4_write.c (revision 63495ad7)
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 and load support in Uboot.
8  *		       Ext4 read optimization taken from Open-Moko
9  *		       Qi bootloader
10  *
11  * (C) Copyright 2004
12  * esd gmbh <www.esd-electronics.com>
13  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
14  *
15  * based on code from grub2 fs/ext2.c and fs/fshelp.c by
16  * GRUB  --  GRand Unified Bootloader
17  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
18  *
19  * ext4write : Based on generic ext4 protocol.
20  *
21  * This program is free software; you can redistribute it and/or modify
22  * it under the terms of the GNU General Public License as published by
23  * the Free Software Foundation; either version 2 of the License, or
24  * (at your option) any later version.
25  *
26  * This program is distributed in the hope that it will be useful,
27  * but WITHOUT ANY WARRANTY; without even the implied warranty of
28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
29  * GNU General Public License for more details.
30  *
31  * You should have received a copy of the GNU General Public License
32  * along with this program; if not, write to the Free Software
33  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34  */
35 
36 
37 #include <common.h>
38 #include <linux/stat.h>
39 #include <div64.h>
40 #include "ext4_common.h"
41 
42 static void ext4fs_update(void)
43 {
44 	short i;
45 	ext4fs_update_journal();
46 	struct ext_filesystem *fs = get_fs();
47 
48 	/* update  super block */
49 	put_ext4((uint64_t)(SUPERBLOCK_SIZE),
50 		 (struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
51 
52 	/* update block groups */
53 	for (i = 0; i < fs->no_blkgrp; i++) {
54 		fs->bgd[i].bg_checksum = ext4fs_checksum_update(i);
55 		put_ext4((uint64_t)(fs->bgd[i].block_id * fs->blksz),
56 			 fs->blk_bmaps[i], fs->blksz);
57 	}
58 
59 	/* update inode table groups */
60 	for (i = 0; i < fs->no_blkgrp; i++) {
61 		put_ext4((uint64_t) (fs->bgd[i].inode_id * fs->blksz),
62 			 fs->inode_bmaps[i], fs->blksz);
63 	}
64 
65 	/* update the block group descriptor table */
66 	put_ext4((uint64_t)(fs->gdtable_blkno * fs->blksz),
67 		 (struct ext2_block_group *)fs->gdtable,
68 		 (fs->blksz * fs->no_blk_pergdt));
69 
70 	ext4fs_dump_metadata();
71 
72 	gindex = 0;
73 	gd_index = 0;
74 }
75 
76 int ext4fs_get_bgdtable(void)
77 {
78 	int status;
79 	int grp_desc_size;
80 	struct ext_filesystem *fs = get_fs();
81 	grp_desc_size = sizeof(struct ext2_block_group);
82 	fs->no_blk_pergdt = (fs->no_blkgrp * grp_desc_size) / fs->blksz;
83 	if ((fs->no_blkgrp * grp_desc_size) % fs->blksz)
84 		fs->no_blk_pergdt++;
85 
86 	/* allocate memory for gdtable */
87 	fs->gdtable = zalloc(fs->blksz * fs->no_blk_pergdt);
88 	if (!fs->gdtable)
89 		return -ENOMEM;
90 	/* read the group descriptor table */
91 	status = ext4fs_devread(fs->gdtable_blkno * fs->sect_perblk, 0,
92 				fs->blksz * fs->no_blk_pergdt, fs->gdtable);
93 	if (status == 0)
94 		goto fail;
95 
96 	if (ext4fs_log_gdt(fs->gdtable)) {
97 		printf("Error in ext4fs_log_gdt\n");
98 		return -1;
99 	}
100 
101 	return 0;
102 fail:
103 	free(fs->gdtable);
104 	fs->gdtable = NULL;
105 
106 	return -1;
107 }
108 
109 static void delete_single_indirect_block(struct ext2_inode *inode)
110 {
111 	struct ext2_block_group *bgd = NULL;
112 	static int prev_bg_bmap_idx = -1;
113 	long int blknr;
114 	int remainder;
115 	int bg_idx;
116 	int status;
117 	unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
118 	struct ext_filesystem *fs = get_fs();
119 	char *journal_buffer = zalloc(fs->blksz);
120 	if (!journal_buffer) {
121 		printf("No memory\n");
122 		return;
123 	}
124 	/* get  block group descriptor table */
125 	bgd = (struct ext2_block_group *)fs->gdtable;
126 
127 	/* deleting the single indirect block associated with inode */
128 	if (inode->b.blocks.indir_block != 0) {
129 		debug("SIPB releasing %u\n", inode->b.blocks.indir_block);
130 		blknr = inode->b.blocks.indir_block;
131 		if (fs->blksz != 1024) {
132 			bg_idx = blknr / blk_per_grp;
133 		} else {
134 			bg_idx = blknr / blk_per_grp;
135 			remainder = blknr % blk_per_grp;
136 			if (!remainder)
137 				bg_idx--;
138 		}
139 		ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
140 		bgd[bg_idx].free_blocks++;
141 		fs->sb->free_blocks++;
142 		/* journal backup */
143 		if (prev_bg_bmap_idx != bg_idx) {
144 			status =
145 			    ext4fs_devread(bgd[bg_idx].block_id *
146 					   fs->sect_perblk, 0, fs->blksz,
147 					   journal_buffer);
148 			if (status == 0)
149 				goto fail;
150 			if (ext4fs_log_journal
151 			    (journal_buffer, bgd[bg_idx].block_id))
152 				goto fail;
153 			prev_bg_bmap_idx = bg_idx;
154 		}
155 	}
156 fail:
157 	free(journal_buffer);
158 }
159 
160 static void delete_double_indirect_block(struct ext2_inode *inode)
161 {
162 	int i;
163 	short status;
164 	static int prev_bg_bmap_idx = -1;
165 	long int blknr;
166 	int remainder;
167 	int bg_idx;
168 	unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
169 	unsigned int *di_buffer = NULL;
170 	unsigned int *DIB_start_addr = NULL;
171 	struct ext2_block_group *bgd = NULL;
172 	struct ext_filesystem *fs = get_fs();
173 	char *journal_buffer = zalloc(fs->blksz);
174 	if (!journal_buffer) {
175 		printf("No memory\n");
176 		return;
177 	}
178 	/* get the block group descriptor table */
179 	bgd = (struct ext2_block_group *)fs->gdtable;
180 
181 	if (inode->b.blocks.double_indir_block != 0) {
182 		di_buffer = zalloc(fs->blksz);
183 		if (!di_buffer) {
184 			printf("No memory\n");
185 			return;
186 		}
187 		DIB_start_addr = (unsigned int *)di_buffer;
188 		blknr = inode->b.blocks.double_indir_block;
189 		status = ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
190 					(char *)di_buffer);
191 		for (i = 0; i < fs->blksz / sizeof(int); i++) {
192 			if (*di_buffer == 0)
193 				break;
194 
195 			debug("DICB releasing %u\n", *di_buffer);
196 			if (fs->blksz != 1024) {
197 				bg_idx = (*di_buffer) / blk_per_grp;
198 			} else {
199 				bg_idx = (*di_buffer) / blk_per_grp;
200 				remainder = (*di_buffer) % blk_per_grp;
201 				if (!remainder)
202 					bg_idx--;
203 			}
204 			ext4fs_reset_block_bmap(*di_buffer,
205 					fs->blk_bmaps[bg_idx], bg_idx);
206 			di_buffer++;
207 			bgd[bg_idx].free_blocks++;
208 			fs->sb->free_blocks++;
209 			/* journal backup */
210 			if (prev_bg_bmap_idx != bg_idx) {
211 				status = ext4fs_devread(bgd[bg_idx].block_id
212 							* fs->sect_perblk, 0,
213 							fs->blksz,
214 							journal_buffer);
215 				if (status == 0)
216 					goto fail;
217 
218 				if (ext4fs_log_journal(journal_buffer,
219 							bgd[bg_idx].block_id))
220 					goto fail;
221 				prev_bg_bmap_idx = bg_idx;
222 			}
223 		}
224 
225 		/* removing the parent double indirect block */
226 		blknr = inode->b.blocks.double_indir_block;
227 		if (fs->blksz != 1024) {
228 			bg_idx = blknr / blk_per_grp;
229 		} else {
230 			bg_idx = blknr / blk_per_grp;
231 			remainder = blknr % blk_per_grp;
232 			if (!remainder)
233 				bg_idx--;
234 		}
235 		ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
236 		bgd[bg_idx].free_blocks++;
237 		fs->sb->free_blocks++;
238 		/* journal backup */
239 		if (prev_bg_bmap_idx != bg_idx) {
240 			memset(journal_buffer, '\0', fs->blksz);
241 			status = ext4fs_devread(bgd[bg_idx].block_id *
242 						fs->sect_perblk, 0, fs->blksz,
243 						journal_buffer);
244 			if (status == 0)
245 				goto fail;
246 
247 			if (ext4fs_log_journal(journal_buffer,
248 						bgd[bg_idx].block_id))
249 				goto fail;
250 			prev_bg_bmap_idx = bg_idx;
251 		}
252 		debug("DIPB releasing %ld\n", blknr);
253 	}
254 fail:
255 	free(DIB_start_addr);
256 	free(journal_buffer);
257 }
258 
259 static void delete_triple_indirect_block(struct ext2_inode *inode)
260 {
261 	int i, j;
262 	short status;
263 	static int prev_bg_bmap_idx = -1;
264 	long int blknr;
265 	int remainder;
266 	int bg_idx;
267 	unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
268 	unsigned int *tigp_buffer = NULL;
269 	unsigned int *tib_start_addr = NULL;
270 	unsigned int *tip_buffer = NULL;
271 	unsigned int *tipb_start_addr = NULL;
272 	struct ext2_block_group *bgd = NULL;
273 	struct ext_filesystem *fs = get_fs();
274 	char *journal_buffer = zalloc(fs->blksz);
275 	if (!journal_buffer) {
276 		printf("No memory\n");
277 		return;
278 	}
279 	/* get block group descriptor table */
280 	bgd = (struct ext2_block_group *)fs->gdtable;
281 
282 	if (inode->b.blocks.triple_indir_block != 0) {
283 		tigp_buffer = zalloc(fs->blksz);
284 		if (!tigp_buffer) {
285 			printf("No memory\n");
286 			return;
287 		}
288 		tib_start_addr = (unsigned int *)tigp_buffer;
289 		blknr = inode->b.blocks.triple_indir_block;
290 		status = ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
291 					(char *)tigp_buffer);
292 		for (i = 0; i < fs->blksz / sizeof(int); i++) {
293 			if (*tigp_buffer == 0)
294 				break;
295 			debug("tigp buffer releasing %u\n", *tigp_buffer);
296 
297 			tip_buffer = zalloc(fs->blksz);
298 			if (!tip_buffer)
299 				goto fail;
300 			tipb_start_addr = (unsigned int *)tip_buffer;
301 			status = ext4fs_devread((*tigp_buffer) *
302 						fs->sect_perblk, 0, fs->blksz,
303 						(char *)tip_buffer);
304 			for (j = 0; j < fs->blksz / sizeof(int); j++) {
305 				if (*tip_buffer == 0)
306 					break;
307 				if (fs->blksz != 1024) {
308 					bg_idx = (*tip_buffer) / blk_per_grp;
309 				} else {
310 					bg_idx = (*tip_buffer) / blk_per_grp;
311 
312 					remainder = (*tip_buffer) % blk_per_grp;
313 					if (!remainder)
314 						bg_idx--;
315 				}
316 
317 				ext4fs_reset_block_bmap(*tip_buffer,
318 							fs->blk_bmaps[bg_idx],
319 							bg_idx);
320 
321 				tip_buffer++;
322 				bgd[bg_idx].free_blocks++;
323 				fs->sb->free_blocks++;
324 				/* journal backup */
325 				if (prev_bg_bmap_idx != bg_idx) {
326 					status =
327 					    ext4fs_devread(
328 							bgd[bg_idx].block_id *
329 							fs->sect_perblk, 0,
330 							fs->blksz,
331 							journal_buffer);
332 					if (status == 0)
333 						goto fail;
334 
335 					if (ext4fs_log_journal(journal_buffer,
336 							       bgd[bg_idx].
337 							       block_id))
338 						goto fail;
339 					prev_bg_bmap_idx = bg_idx;
340 				}
341 			}
342 			free(tipb_start_addr);
343 			tipb_start_addr = NULL;
344 
345 			/*
346 			 * removing the grand parent blocks
347 			 * which is connected to inode
348 			 */
349 			if (fs->blksz != 1024) {
350 				bg_idx = (*tigp_buffer) / blk_per_grp;
351 			} else {
352 				bg_idx = (*tigp_buffer) / blk_per_grp;
353 
354 				remainder = (*tigp_buffer) % blk_per_grp;
355 				if (!remainder)
356 					bg_idx--;
357 			}
358 			ext4fs_reset_block_bmap(*tigp_buffer,
359 						fs->blk_bmaps[bg_idx], bg_idx);
360 
361 			tigp_buffer++;
362 			bgd[bg_idx].free_blocks++;
363 			fs->sb->free_blocks++;
364 			/* journal backup */
365 			if (prev_bg_bmap_idx != bg_idx) {
366 				memset(journal_buffer, '\0', fs->blksz);
367 				status =
368 				    ext4fs_devread(bgd[bg_idx].block_id *
369 						   fs->sect_perblk, 0,
370 						   fs->blksz, journal_buffer);
371 				if (status == 0)
372 					goto fail;
373 
374 				if (ext4fs_log_journal(journal_buffer,
375 							bgd[bg_idx].block_id))
376 					goto fail;
377 				prev_bg_bmap_idx = bg_idx;
378 			}
379 		}
380 
381 		/* removing the grand parent triple indirect block */
382 		blknr = inode->b.blocks.triple_indir_block;
383 		if (fs->blksz != 1024) {
384 			bg_idx = blknr / blk_per_grp;
385 		} else {
386 			bg_idx = blknr / blk_per_grp;
387 			remainder = blknr % blk_per_grp;
388 			if (!remainder)
389 				bg_idx--;
390 		}
391 		ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
392 		bgd[bg_idx].free_blocks++;
393 		fs->sb->free_blocks++;
394 		/* journal backup */
395 		if (prev_bg_bmap_idx != bg_idx) {
396 			memset(journal_buffer, '\0', fs->blksz);
397 			status = ext4fs_devread(bgd[bg_idx].block_id *
398 						fs->sect_perblk, 0, fs->blksz,
399 						journal_buffer);
400 			if (status == 0)
401 				goto fail;
402 
403 			if (ext4fs_log_journal(journal_buffer,
404 						bgd[bg_idx].block_id))
405 				goto fail;
406 			prev_bg_bmap_idx = bg_idx;
407 		}
408 		debug("tigp buffer itself releasing %ld\n", blknr);
409 	}
410 fail:
411 	free(tib_start_addr);
412 	free(tipb_start_addr);
413 	free(journal_buffer);
414 }
415 
416 static int ext4fs_delete_file(int inodeno)
417 {
418 	struct ext2_inode inode;
419 	short status;
420 	int i;
421 	int remainder;
422 	long int blknr;
423 	int bg_idx;
424 	int ibmap_idx;
425 	char *read_buffer = NULL;
426 	char *start_block_address = NULL;
427 	unsigned int no_blocks;
428 
429 	static int prev_bg_bmap_idx = -1;
430 	unsigned int inodes_per_block;
431 	long int blkno;
432 	unsigned int blkoff;
433 	unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
434 	unsigned int inode_per_grp = ext4fs_root->sblock.inodes_per_group;
435 	struct ext2_inode *inode_buffer = NULL;
436 	struct ext2_block_group *bgd = NULL;
437 	struct ext_filesystem *fs = get_fs();
438 	char *journal_buffer = zalloc(fs->blksz);
439 	if (!journal_buffer)
440 		return -ENOMEM;
441 	/* get the block group descriptor table */
442 	bgd = (struct ext2_block_group *)fs->gdtable;
443 	status = ext4fs_read_inode(ext4fs_root, inodeno, &inode);
444 	if (status == 0)
445 		goto fail;
446 
447 	/* read the block no allocated to a file */
448 	no_blocks = inode.size / fs->blksz;
449 	if (inode.size % fs->blksz)
450 		no_blocks++;
451 
452 	if (le32_to_cpu(inode.flags) & EXT4_EXTENTS_FL) {
453 		struct ext2fs_node *node_inode =
454 		    zalloc(sizeof(struct ext2fs_node));
455 		if (!node_inode)
456 			goto fail;
457 		node_inode->data = ext4fs_root;
458 		node_inode->ino = inodeno;
459 		node_inode->inode_read = 0;
460 		memcpy(&(node_inode->inode), &inode, sizeof(struct ext2_inode));
461 
462 		for (i = 0; i < no_blocks; i++) {
463 			blknr = read_allocated_block(&(node_inode->inode), i);
464 			if (fs->blksz != 1024) {
465 				bg_idx = blknr / blk_per_grp;
466 			} else {
467 				bg_idx = blknr / blk_per_grp;
468 				remainder = blknr % blk_per_grp;
469 				if (!remainder)
470 					bg_idx--;
471 			}
472 			ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx],
473 						bg_idx);
474 			debug("EXT4_EXTENTS Block releasing %ld: %d\n",
475 			      blknr, bg_idx);
476 
477 			bgd[bg_idx].free_blocks++;
478 			fs->sb->free_blocks++;
479 
480 			/* journal backup */
481 			if (prev_bg_bmap_idx != bg_idx) {
482 				status =
483 				    ext4fs_devread(bgd[bg_idx].block_id *
484 						   fs->sect_perblk, 0,
485 						   fs->blksz, journal_buffer);
486 				if (status == 0)
487 					goto fail;
488 				if (ext4fs_log_journal(journal_buffer,
489 							bgd[bg_idx].block_id))
490 					goto fail;
491 				prev_bg_bmap_idx = bg_idx;
492 			}
493 		}
494 		if (node_inode) {
495 			free(node_inode);
496 			node_inode = NULL;
497 		}
498 	} else {
499 
500 		delete_single_indirect_block(&inode);
501 		delete_double_indirect_block(&inode);
502 		delete_triple_indirect_block(&inode);
503 
504 		/* read the block no allocated to a file */
505 		no_blocks = inode.size / fs->blksz;
506 		if (inode.size % fs->blksz)
507 			no_blocks++;
508 		for (i = 0; i < no_blocks; i++) {
509 			blknr = read_allocated_block(&inode, i);
510 			if (fs->blksz != 1024) {
511 				bg_idx = blknr / blk_per_grp;
512 			} else {
513 				bg_idx = blknr / blk_per_grp;
514 				remainder = blknr % blk_per_grp;
515 				if (!remainder)
516 					bg_idx--;
517 			}
518 			ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx],
519 						bg_idx);
520 			debug("ActualB releasing %ld: %d\n", blknr, bg_idx);
521 
522 			bgd[bg_idx].free_blocks++;
523 			fs->sb->free_blocks++;
524 			/* journal backup */
525 			if (prev_bg_bmap_idx != bg_idx) {
526 				memset(journal_buffer, '\0', fs->blksz);
527 				status = ext4fs_devread(bgd[bg_idx].block_id
528 							* fs->sect_perblk,
529 							0, fs->blksz,
530 							journal_buffer);
531 				if (status == 0)
532 					goto fail;
533 				if (ext4fs_log_journal(journal_buffer,
534 						bgd[bg_idx].block_id))
535 					goto fail;
536 				prev_bg_bmap_idx = bg_idx;
537 			}
538 		}
539 	}
540 
541 	/* from the inode no to blockno */
542 	inodes_per_block = fs->blksz / fs->inodesz;
543 	ibmap_idx = inodeno / inode_per_grp;
544 
545 	/* get the block no */
546 	inodeno--;
547 	blkno = __le32_to_cpu(bgd[ibmap_idx].inode_table_id) +
548 		(inodeno % __le32_to_cpu(inode_per_grp)) / inodes_per_block;
549 
550 	/* get the offset of the inode */
551 	blkoff = ((inodeno) % inodes_per_block) * fs->inodesz;
552 
553 	/* read the block no containing the inode */
554 	read_buffer = zalloc(fs->blksz);
555 	if (!read_buffer)
556 		goto fail;
557 	start_block_address = read_buffer;
558 	status = ext4fs_devread(blkno * fs->sect_perblk,
559 				0, fs->blksz, read_buffer);
560 	if (status == 0)
561 		goto fail;
562 
563 	if (ext4fs_log_journal(read_buffer, blkno))
564 		goto fail;
565 
566 	read_buffer = read_buffer + blkoff;
567 	inode_buffer = (struct ext2_inode *)read_buffer;
568 	memset(inode_buffer, '\0', sizeof(struct ext2_inode));
569 
570 	/* write the inode to original position in inode table */
571 	if (ext4fs_put_metadata(start_block_address, blkno))
572 		goto fail;
573 
574 	/* update the respective inode bitmaps */
575 	inodeno++;
576 	ext4fs_reset_inode_bmap(inodeno, fs->inode_bmaps[ibmap_idx], ibmap_idx);
577 	bgd[ibmap_idx].free_inodes++;
578 	fs->sb->free_inodes++;
579 	/* journal backup */
580 	memset(journal_buffer, '\0', fs->blksz);
581 	status = ext4fs_devread(bgd[ibmap_idx].inode_id *
582 				fs->sect_perblk, 0, fs->blksz, journal_buffer);
583 	if (status == 0)
584 		goto fail;
585 	if (ext4fs_log_journal(journal_buffer, bgd[ibmap_idx].inode_id))
586 		goto fail;
587 
588 	ext4fs_update();
589 	ext4fs_deinit();
590 
591 	if (ext4fs_init() != 0) {
592 		printf("error in File System init\n");
593 		goto fail;
594 	}
595 
596 	free(start_block_address);
597 	free(journal_buffer);
598 
599 	return 0;
600 fail:
601 	free(start_block_address);
602 	free(journal_buffer);
603 
604 	return -1;
605 }
606 
607 int ext4fs_init(void)
608 {
609 	short status;
610 	int i;
611 	unsigned int real_free_blocks = 0;
612 	struct ext_filesystem *fs = get_fs();
613 
614 	/* populate fs */
615 	fs->blksz = EXT2_BLOCK_SIZE(ext4fs_root);
616 	fs->inodesz = INODE_SIZE_FILESYSTEM(ext4fs_root);
617 	fs->sect_perblk = fs->blksz / SECTOR_SIZE;
618 
619 	/* get the superblock */
620 	fs->sb = zalloc(SUPERBLOCK_SIZE);
621 	if (!fs->sb)
622 		return -ENOMEM;
623 	if (!ext4fs_devread(SUPERBLOCK_SECTOR, 0, SUPERBLOCK_SIZE,
624 			(char *)fs->sb))
625 		goto fail;
626 
627 	/* init journal */
628 	if (ext4fs_init_journal())
629 		goto fail;
630 
631 	/* get total no of blockgroups */
632 	fs->no_blkgrp = (uint32_t)ext4fs_div_roundup(
633 			(ext4fs_root->sblock.total_blocks -
634 			ext4fs_root->sblock.first_data_block),
635 			ext4fs_root->sblock.blocks_per_group);
636 
637 	/* get the block group descriptor table */
638 	fs->gdtable_blkno = ((EXT2_MIN_BLOCK_SIZE == fs->blksz) + 1);
639 	if (ext4fs_get_bgdtable() == -1) {
640 		printf("Error in getting the block group descriptor table\n");
641 		goto fail;
642 	}
643 	fs->bgd = (struct ext2_block_group *)fs->gdtable;
644 
645 	/* load all the available bitmap block of the partition */
646 	fs->blk_bmaps = zalloc(fs->no_blkgrp * sizeof(char *));
647 	if (!fs->blk_bmaps)
648 		goto fail;
649 	for (i = 0; i < fs->no_blkgrp; i++) {
650 		fs->blk_bmaps[i] = zalloc(fs->blksz);
651 		if (!fs->blk_bmaps[i])
652 			goto fail;
653 	}
654 
655 	for (i = 0; i < fs->no_blkgrp; i++) {
656 		status =
657 		    ext4fs_devread(fs->bgd[i].block_id * fs->sect_perblk, 0,
658 				   fs->blksz, (char *)fs->blk_bmaps[i]);
659 		if (status == 0)
660 			goto fail;
661 	}
662 
663 	/* load all the available inode bitmap of the partition */
664 	fs->inode_bmaps = zalloc(fs->no_blkgrp * sizeof(unsigned char *));
665 	if (!fs->inode_bmaps)
666 		goto fail;
667 	for (i = 0; i < fs->no_blkgrp; i++) {
668 		fs->inode_bmaps[i] = zalloc(fs->blksz);
669 		if (!fs->inode_bmaps[i])
670 			goto fail;
671 	}
672 
673 	for (i = 0; i < fs->no_blkgrp; i++) {
674 		status = ext4fs_devread(fs->bgd[i].inode_id * fs->sect_perblk,
675 					0, fs->blksz,
676 					(char *)fs->inode_bmaps[i]);
677 		if (status == 0)
678 			goto fail;
679 	}
680 
681 	/*
682 	 * check filesystem consistency with free blocks of file system
683 	 * some time we observed that superblock freeblocks does not match
684 	 * with the  blockgroups freeblocks when improper
685 	 * reboot of a linux kernel
686 	 */
687 	for (i = 0; i < fs->no_blkgrp; i++)
688 		real_free_blocks = real_free_blocks + fs->bgd[i].free_blocks;
689 	if (real_free_blocks != fs->sb->free_blocks)
690 		fs->sb->free_blocks = real_free_blocks;
691 
692 	return 0;
693 fail:
694 	ext4fs_deinit();
695 
696 	return -1;
697 }
698 
699 void ext4fs_deinit(void)
700 {
701 	int i;
702 	struct ext2_inode inode_journal;
703 	struct journal_superblock_t *jsb;
704 	long int blknr;
705 	struct ext_filesystem *fs = get_fs();
706 
707 	/* free journal */
708 	char *temp_buff = zalloc(fs->blksz);
709 	if (temp_buff) {
710 		ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO,
711 				  &inode_journal);
712 		blknr = read_allocated_block(&inode_journal,
713 					EXT2_JOURNAL_SUPERBLOCK);
714 		ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
715 			       temp_buff);
716 		jsb = (struct journal_superblock_t *)temp_buff;
717 		jsb->s_start = cpu_to_be32(0);
718 		put_ext4((uint64_t) (blknr * fs->blksz),
719 			 (struct journal_superblock_t *)temp_buff, fs->blksz);
720 		free(temp_buff);
721 	}
722 	ext4fs_free_journal();
723 
724 	/* get the superblock */
725 	ext4fs_devread(SUPERBLOCK_SECTOR, 0, SUPERBLOCK_SIZE, (char *)fs->sb);
726 	fs->sb->feature_incompat &= ~EXT3_FEATURE_INCOMPAT_RECOVER;
727 	put_ext4((uint64_t)(SUPERBLOCK_SIZE),
728 		 (struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
729 	free(fs->sb);
730 	fs->sb = NULL;
731 
732 	if (fs->blk_bmaps) {
733 		for (i = 0; i < fs->no_blkgrp; i++) {
734 			free(fs->blk_bmaps[i]);
735 			fs->blk_bmaps[i] = NULL;
736 		}
737 		free(fs->blk_bmaps);
738 		fs->blk_bmaps = NULL;
739 	}
740 
741 	if (fs->inode_bmaps) {
742 		for (i = 0; i < fs->no_blkgrp; i++) {
743 			free(fs->inode_bmaps[i]);
744 			fs->inode_bmaps[i] = NULL;
745 		}
746 		free(fs->inode_bmaps);
747 		fs->inode_bmaps = NULL;
748 	}
749 
750 
751 	free(fs->gdtable);
752 	fs->gdtable = NULL;
753 	fs->bgd = NULL;
754 	/*
755 	 * reinitiliazed the global inode and
756 	 * block bitmap first execution check variables
757 	 */
758 	fs->first_pass_ibmap = 0;
759 	fs->first_pass_bbmap = 0;
760 	fs->curr_inode_no = 0;
761 	fs->curr_blkno = 0;
762 }
763 
764 static int ext4fs_write_file(struct ext2_inode *file_inode,
765 			     int pos, unsigned int len, char *buf)
766 {
767 	int i;
768 	int blockcnt;
769 	int log2blocksize = LOG2_EXT2_BLOCK_SIZE(ext4fs_root);
770 	unsigned int filesize = __le32_to_cpu(file_inode->size);
771 	struct ext_filesystem *fs = get_fs();
772 	int previous_block_number = -1;
773 	int delayed_start = 0;
774 	int delayed_extent = 0;
775 	int delayed_next = 0;
776 	char *delayed_buf = NULL;
777 
778 	/* Adjust len so it we can't read past the end of the file. */
779 	if (len > filesize)
780 		len = filesize;
781 
782 	blockcnt = ((len + pos) + fs->blksz - 1) / fs->blksz;
783 
784 	for (i = pos / fs->blksz; i < blockcnt; i++) {
785 		long int blknr;
786 		int blockend = fs->blksz;
787 		int skipfirst = 0;
788 		blknr = read_allocated_block(file_inode, i);
789 		if (blknr < 0)
790 			return -1;
791 
792 		blknr = blknr << log2blocksize;
793 
794 		if (blknr) {
795 			if (previous_block_number != -1) {
796 				if (delayed_next == blknr) {
797 					delayed_extent += blockend;
798 					delayed_next += blockend >> SECTOR_BITS;
799 				} else {	/* spill */
800 					put_ext4((uint64_t) (delayed_start *
801 							     SECTOR_SIZE),
802 						 delayed_buf,
803 						 (uint32_t) delayed_extent);
804 					previous_block_number = blknr;
805 					delayed_start = blknr;
806 					delayed_extent = blockend;
807 					delayed_buf = buf;
808 					delayed_next = blknr +
809 					    (blockend >> SECTOR_BITS);
810 				}
811 			} else {
812 				previous_block_number = blknr;
813 				delayed_start = blknr;
814 				delayed_extent = blockend;
815 				delayed_buf = buf;
816 				delayed_next = blknr +
817 				    (blockend >> SECTOR_BITS);
818 			}
819 		} else {
820 			if (previous_block_number != -1) {
821 				/* spill */
822 				put_ext4((uint64_t) (delayed_start *
823 						     SECTOR_SIZE), delayed_buf,
824 					 (uint32_t) delayed_extent);
825 				previous_block_number = -1;
826 			}
827 			memset(buf, 0, fs->blksz - skipfirst);
828 		}
829 		buf += fs->blksz - skipfirst;
830 	}
831 	if (previous_block_number != -1) {
832 		/* spill */
833 		put_ext4((uint64_t) (delayed_start * SECTOR_SIZE),
834 			 delayed_buf, (uint32_t) delayed_extent);
835 		previous_block_number = -1;
836 	}
837 
838 	return len;
839 }
840 
841 int ext4fs_write(const char *fname, unsigned char *buffer,
842 					unsigned long sizebytes)
843 {
844 	int ret = 0;
845 	struct ext2_inode *file_inode = NULL;
846 	unsigned char *inode_buffer = NULL;
847 	int parent_inodeno;
848 	int inodeno;
849 	time_t timestamp = 0;
850 
851 	uint64_t bytes_reqd_for_file;
852 	unsigned int blks_reqd_for_file;
853 	unsigned int blocks_remaining;
854 	int existing_file_inodeno;
855 	char *temp_ptr = NULL;
856 	long int itable_blkno;
857 	long int parent_itable_blkno;
858 	long int blkoff;
859 	struct ext2_sblock *sblock = &(ext4fs_root->sblock);
860 	unsigned int inodes_per_block;
861 	unsigned int ibmap_idx;
862 	struct ext_filesystem *fs = get_fs();
863 	ALLOC_CACHE_ALIGN_BUFFER(char, filename, 256);
864 	memset(filename, 0x00, sizeof(filename));
865 
866 	g_parent_inode = zalloc(sizeof(struct ext2_inode));
867 	if (!g_parent_inode)
868 		goto fail;
869 
870 	if (ext4fs_init() != 0) {
871 		printf("error in File System init\n");
872 		return -1;
873 	}
874 	inodes_per_block = fs->blksz / fs->inodesz;
875 	parent_inodeno = ext4fs_get_parent_inode_num(fname, filename, F_FILE);
876 	if (parent_inodeno == -1)
877 		goto fail;
878 	if (ext4fs_iget(parent_inodeno, g_parent_inode))
879 		goto fail;
880 	/* check if the filename is already present in root */
881 	existing_file_inodeno = ext4fs_filename_check(filename);
882 	if (existing_file_inodeno != -1) {
883 		ret = ext4fs_delete_file(existing_file_inodeno);
884 		fs->first_pass_bbmap = 0;
885 		fs->curr_blkno = 0;
886 
887 		fs->first_pass_ibmap = 0;
888 		fs->curr_inode_no = 0;
889 		if (ret)
890 			goto fail;
891 	}
892 	/* calucalate how many blocks required */
893 	bytes_reqd_for_file = sizebytes;
894 	blks_reqd_for_file = lldiv(bytes_reqd_for_file, fs->blksz);
895 	if (do_div(bytes_reqd_for_file, fs->blksz) != 0) {
896 		blks_reqd_for_file++;
897 		debug("total bytes for a file %u\n", blks_reqd_for_file);
898 	}
899 	blocks_remaining = blks_reqd_for_file;
900 	/* test for available space in partition */
901 	if (fs->sb->free_blocks < blks_reqd_for_file) {
902 		printf("Not enough space on partition !!!\n");
903 		goto fail;
904 	}
905 
906 	ext4fs_update_parent_dentry(filename, &inodeno, FILETYPE_REG);
907 	/* prepare file inode */
908 	inode_buffer = zalloc(fs->inodesz);
909 	if (!inode_buffer)
910 		goto fail;
911 	file_inode = (struct ext2_inode *)inode_buffer;
912 	file_inode->mode = S_IFREG | S_IRWXU |
913 	    S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH;
914 	/* ToDo: Update correct time */
915 	file_inode->mtime = timestamp;
916 	file_inode->atime = timestamp;
917 	file_inode->ctime = timestamp;
918 	file_inode->nlinks = 1;
919 	file_inode->size = sizebytes;
920 
921 	/* Allocate data blocks */
922 	ext4fs_allocate_blocks(file_inode, blocks_remaining,
923 			       &blks_reqd_for_file);
924 	file_inode->blockcnt = (blks_reqd_for_file * fs->blksz) / SECTOR_SIZE;
925 
926 	temp_ptr = zalloc(fs->blksz);
927 	if (!temp_ptr)
928 		goto fail;
929 	ibmap_idx = inodeno / ext4fs_root->sblock.inodes_per_group;
930 	inodeno--;
931 	itable_blkno = __le32_to_cpu(fs->bgd[ibmap_idx].inode_table_id) +
932 			(inodeno % __le32_to_cpu(sblock->inodes_per_group)) /
933 			inodes_per_block;
934 	blkoff = (inodeno % inodes_per_block) * fs->inodesz;
935 	ext4fs_devread(itable_blkno * fs->sect_perblk, 0, fs->blksz, temp_ptr);
936 	if (ext4fs_log_journal(temp_ptr, itable_blkno))
937 		goto fail;
938 
939 	memcpy(temp_ptr + blkoff, inode_buffer, fs->inodesz);
940 	if (ext4fs_put_metadata(temp_ptr, itable_blkno))
941 		goto fail;
942 	/* copy the file content into data blocks */
943 	if (ext4fs_write_file(file_inode, 0, sizebytes, (char *)buffer) == -1) {
944 		printf("Error in copying content\n");
945 		goto fail;
946 	}
947 	ibmap_idx = parent_inodeno / ext4fs_root->sblock.inodes_per_group;
948 	parent_inodeno--;
949 	parent_itable_blkno = __le32_to_cpu(fs->bgd[ibmap_idx].inode_table_id) +
950 	    (parent_inodeno %
951 	     __le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
952 	blkoff = (parent_inodeno % inodes_per_block) * fs->inodesz;
953 	if (parent_itable_blkno != itable_blkno) {
954 		memset(temp_ptr, '\0', fs->blksz);
955 		ext4fs_devread(parent_itable_blkno * fs->sect_perblk,
956 			       0, fs->blksz, temp_ptr);
957 		if (ext4fs_log_journal(temp_ptr, parent_itable_blkno))
958 			goto fail;
959 
960 		memcpy(temp_ptr + blkoff, g_parent_inode,
961 			sizeof(struct ext2_inode));
962 		if (ext4fs_put_metadata(temp_ptr, parent_itable_blkno))
963 			goto fail;
964 		free(temp_ptr);
965 	} else {
966 		/*
967 		 * If parent and child fall in same inode table block
968 		 * both should be kept in 1 buffer
969 		 */
970 		memcpy(temp_ptr + blkoff, g_parent_inode,
971 		       sizeof(struct ext2_inode));
972 		gd_index--;
973 		if (ext4fs_put_metadata(temp_ptr, itable_blkno))
974 			goto fail;
975 		free(temp_ptr);
976 	}
977 	ext4fs_update();
978 	ext4fs_deinit();
979 
980 	fs->first_pass_bbmap = 0;
981 	fs->curr_blkno = 0;
982 	fs->first_pass_ibmap = 0;
983 	fs->curr_inode_no = 0;
984 	free(inode_buffer);
985 	free(g_parent_inode);
986 	g_parent_inode = NULL;
987 
988 	return 0;
989 fail:
990 	ext4fs_deinit();
991 	free(inode_buffer);
992 	free(g_parent_inode);
993 	g_parent_inode = NULL;
994 
995 	return -1;
996 }
997