fs/ext4/ext4fs.c

   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 #include <common.h>
  37 #include <malloc.h>
  38 #include <ext_common.h>
  39 #include <ext4fs.h>
  40 #include <linux/stat.h>
  41 #include <linux/time.h>
  42 #include <asm/byteorder.h>
  43 #include "ext4_common.h"
  44
  45 int ext4fs_symlinknest;
  46 struct ext_filesystem ext_fs;
  47
  48 struct ext_filesystem *get_fs(void)
  49 {
  50         return &ext_fs;
  51 }
  52
  53 void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
  54 {
  55         if ((node != &ext4fs_root->diropen) && (node != currroot))
  56                 free(node);
  57 }
  58
  59 /*
  60  * Taken from openmoko-kernel mailing list: By Andy green
  61  * Optimized read file API : collects and defers contiguous sector
  62  * reads into one potentially more efficient larger sequential read action
  63  */
  64 int ext4fs_read_file(struct ext2fs_node *node, int pos,
  65                 unsigned int len, char *buf)
  66 {
  67         int i;
  68         int blockcnt;
  69         int log2blocksize = LOG2_EXT2_BLOCK_SIZE(node->data);
  70         int blocksize = 1 << (log2blocksize + DISK_SECTOR_BITS);
  71         unsigned int filesize = __le32_to_cpu(node->inode.size);
  72         int previous_block_number = -1;
  73         int delayed_start = 0;
  74         int delayed_extent = 0;
  75         int delayed_skipfirst = 0;
  76         int delayed_next = 0;
  77         char *delayed_buf = NULL;
  78         short status;
  79
  80         /* Adjust len so it we can't read past the end of the file. */
  81         if (len > filesize)
  82                 len = filesize;
  83
  84         blockcnt = ((len + pos) + blocksize - 1) / blocksize;
  85
  86         for (i = pos / blocksize; i < blockcnt; i++) {
  87                 int blknr;
  88                 int blockoff = pos % blocksize;
  89                 int blockend = blocksize;
  90                 int skipfirst = 0;
  91                 blknr = read_allocated_block(&(node->inode), i);
  92                 if (blknr < 0)
  93                         return -1;
  94
  95                 blknr = blknr << log2blocksize;
  96
  97                 /* Last block.  */
  98                 if (i == blockcnt - 1) {
  99                         blockend = (len + pos) % blocksize;
 100
 101                         /* The last portion is exactly blocksize. */
 102                         if (!blockend)
 103                                 blockend = blocksize;
 104                 }
 105
 106                 /* First block. */
 107                 if (i == pos / blocksize) {
 108                         skipfirst = blockoff;
 109                         blockend -= skipfirst;
 110                 }
 111                 if (blknr) {
 112                         int status;
 113
 114                         if (previous_block_number != -1) {
 115                                 if (delayed_next == blknr) {
 116                                         delayed_extent += blockend;
 117                                         delayed_next += blockend >> SECTOR_BITS;
 118                                 } else {        /* spill */
 119                                         status = ext4fs_devread(delayed_start,
 120                                                         delayed_skipfirst,
 121                                                         delayed_extent,
 122                                                         delayed_buf);
 123                                         if (status == 0)
 124                                                 return -1;
 125                                         previous_block_number = blknr;
 126                                         delayed_start = blknr;
 127                                         delayed_extent = blockend;
 128                                         delayed_skipfirst = skipfirst;
 129                                         delayed_buf = buf;
 130                                         delayed_next = blknr +
 131                                                 (blockend >> SECTOR_BITS);
 132                                 }
 133                         } else {
 134                                 previous_block_number = blknr;
 135                                 delayed_start = blknr;
 136                                 delayed_extent = blockend;
 137                                 delayed_skipfirst = skipfirst;
 138                                 delayed_buf = buf;
 139                                 delayed_next = blknr +
 140                                         (blockend >> SECTOR_BITS);
 141                         }
 142                 } else {
 143                         if (previous_block_number != -1) {
 144                                 /* spill */
 145                                 status = ext4fs_devread(delayed_start,
 146                                                         delayed_skipfirst,
 147                                                         delayed_extent,
 148                                                         delayed_buf);
 149                                 if (status == 0)
 150                                         return -1;
 151                                 previous_block_number = -1;
 152                         }
 153                         memset(buf, 0, blocksize - skipfirst);
 154                 }
 155                 buf += blocksize - skipfirst;
 156         }
 157         if (previous_block_number != -1) {
 158                 /* spill */
 159                 status = ext4fs_devread(delayed_start,
 160                                         delayed_skipfirst, delayed_extent,
 161                                         delayed_buf);
 162                 if (status == 0)
 163                         return -1;
 164                 previous_block_number = -1;
 165         }
 166
 167         return len;
 168 }
 169
 170 int ext4fs_ls(const char *dirname)
 171 {
 172         struct ext2fs_node *dirnode;
 173         int status;
 174
 175         if (dirname == NULL)
 176                 return 0;
 177
 178         status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
 179                                   FILETYPE_DIRECTORY);
 180         if (status != 1) {
 181                 printf("** Can not find directory. **\n");
 182                 return 1;
 183         }
 184
 185         ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
 186         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 187
 188         return 0;
 189 }
 190
 191 int ext4fs_read(char *buf, unsigned len)
 192 {
 193         if (ext4fs_root == NULL || ext4fs_file == NULL)
 194                 return 0;
 195
 196         return ext4fs_read_file(ext4fs_file, 0, len, buf);
 197 }
 198
 199 #if defined(CONFIG_CMD_EXT4_WRITE)
 200 static void ext4fs_update(void)
 201 {
 202         short i;
 203         ext4fs_update_journal();
 204         struct ext_filesystem *fs = get_fs();
 205
 206         /* update  super block */
 207         put_ext4((uint64_t)(SUPERBLOCK_SIZE),
 208                  (struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
 209
 210         /* update block groups */
 211         for (i = 0; i < fs->no_blkgrp; i++) {
 212                 fs->bgd[i].bg_checksum = ext4fs_checksum_update(i);
 213                 put_ext4((uint64_t)(fs->bgd[i].block_id * fs->blksz),
 214                          fs->blk_bmaps[i], fs->blksz);
 215         }
 216
 217         /* update inode table groups */
 218         for (i = 0; i < fs->no_blkgrp; i++) {
 219                 put_ext4((uint64_t) (fs->bgd[i].inode_id * fs->blksz),
 220                          fs->inode_bmaps[i], fs->blksz);
 221         }
 222
 223         /* update the block group descriptor table */
 224         put_ext4((uint64_t)(fs->gdtable_blkno * fs->blksz),
 225                  (struct ext2_block_group *)fs->gdtable,
 226                  (fs->blksz * fs->no_blk_pergdt));
 227
 228         ext4fs_dump_metadata();
 229
 230         gindex = 0;
 231         gd_index = 0;
 232 }
 233
 234 int ext4fs_get_bgdtable(void)
 235 {
 236         int status;
 237         int grp_desc_size;
 238         struct ext_filesystem *fs = get_fs();
 239         grp_desc_size = sizeof(struct ext2_block_group);
 240         fs->no_blk_pergdt = (fs->no_blkgrp * grp_desc_size) / fs->blksz;
 241         if ((fs->no_blkgrp * grp_desc_size) % fs->blksz)
 242                 fs->no_blk_pergdt++;
 243
 244         /* allocate memory for gdtable */
 245         fs->gdtable = zalloc(fs->blksz * fs->no_blk_pergdt);
 246         if (!fs->gdtable)
 247                 return -ENOMEM;
 248         /* read the group descriptor table */
 249         status = ext4fs_devread(fs->gdtable_blkno * fs->sect_perblk, 0,
 250                                 fs->blksz * fs->no_blk_pergdt, fs->gdtable);
 251         if (status == 0)
 252                 goto fail;
 253
 254         if (ext4fs_log_gdt(fs->gdtable)) {
 255                 printf("Error in ext4fs_log_gdt\n");
 256                 return -1;
 257         }
 258
 259         return 0;
 260 fail:
 261         free(fs->gdtable);
 262         fs->gdtable = NULL;
 263
 264         return -1;
 265 }
 266
 267 static void delete_single_indirect_block(struct ext2_inode *inode)
 268 {
 269         struct ext2_block_group *bgd = NULL;
 270         static int prev_bg_bmap_idx = -1;
 271         long int blknr;
 272         int remainder;
 273         int bg_idx;
 274         int status;
 275         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 276         struct ext_filesystem *fs = get_fs();
 277         char *journal_buffer = zalloc(fs->blksz);
 278         if (!journal_buffer) {
 279                 printf("No memory\n");
 280                 return;
 281         }
 282         /* get  block group descriptor table */
 283         bgd = (struct ext2_block_group *)fs->gdtable;
 284
 285         /* deleting the single indirect block associated with inode */
 286         if (inode->b.blocks.indir_block != 0) {
 287                 debug("SIPB releasing %u\n", inode->b.blocks.indir_block);
 288                 blknr = inode->b.blocks.indir_block;
 289                 if (fs->blksz != 1024) {
 290                         bg_idx = blknr / blk_per_grp;
 291                 } else {
 292                         bg_idx = blknr / blk_per_grp;
 293                         remainder = blknr % blk_per_grp;
 294                         if (!remainder)
 295                                 bg_idx--;
 296                 }
 297                 ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
 298                 bgd[bg_idx].free_blocks++;
 299                 fs->sb->free_blocks++;
 300                 /* journal backup */
 301                 if (prev_bg_bmap_idx != bg_idx) {
 302                         status =
 303                             ext4fs_devread(bgd[bg_idx].block_id *
 304                                            fs->sect_perblk, 0, fs->blksz,
 305                                            journal_buffer);
 306                         if (status == 0)
 307                                 goto fail;
 308                         if (ext4fs_log_journal
 309                             (journal_buffer, bgd[bg_idx].block_id))
 310                                 goto fail;
 311                         prev_bg_bmap_idx = bg_idx;
 312                 }
 313         }
 314 fail:
 315         free(journal_buffer);
 316 }
 317
 318 static void delete_double_indirect_block(struct ext2_inode *inode)
 319 {
 320         int i;
 321         short status;
 322         static int prev_bg_bmap_idx = -1;
 323         long int blknr;
 324         int remainder;
 325         int bg_idx;
 326         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 327         unsigned int *di_buffer = NULL;
 328         unsigned int *DIB_start_addr = NULL;
 329         struct ext2_block_group *bgd = NULL;
 330         struct ext_filesystem *fs = get_fs();
 331         char *journal_buffer = zalloc(fs->blksz);
 332         if (!journal_buffer) {
 333                 printf("No memory\n");
 334                 return;
 335         }
 336         /* get the block group descriptor table */
 337         bgd = (struct ext2_block_group *)fs->gdtable;
 338
 339         if (inode->b.blocks.double_indir_block != 0) {
 340                 di_buffer = zalloc(fs->blksz);
 341                 if (!di_buffer) {
 342                         printf("No memory\n");
 343                         return;
 344                 }
 345                 DIB_start_addr = (unsigned int *)di_buffer;
 346                 blknr = inode->b.blocks.double_indir_block;
 347                 status = ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
 348                                         (char *)di_buffer);
 349                 for (i = 0; i < fs->blksz / sizeof(int); i++) {
 350                         if (*di_buffer == 0)
 351                                 break;
 352
 353                         debug("DICB releasing %u\n", *di_buffer);
 354                         if (fs->blksz != 1024) {
 355                                 bg_idx = (*di_buffer) / blk_per_grp;
 356                         } else {
 357                                 bg_idx = (*di_buffer) / blk_per_grp;
 358                                 remainder = (*di_buffer) % blk_per_grp;
 359                                 if (!remainder)
 360                                         bg_idx--;
 361                         }
 362                         ext4fs_reset_block_bmap(*di_buffer,
 363                                         fs->blk_bmaps[bg_idx], bg_idx);
 364                         di_buffer++;
 365                         bgd[bg_idx].free_blocks++;
 366                         fs->sb->free_blocks++;
 367                         /* journal backup */
 368                         if (prev_bg_bmap_idx != bg_idx) {
 369                                 status = ext4fs_devread(bgd[bg_idx].block_id
 370                                                         * fs->sect_perblk, 0,
 371                                                         fs->blksz,
 372                                                         journal_buffer);
 373                                 if (status == 0)
 374                                         goto fail;
 375
 376                                 if (ext4fs_log_journal(journal_buffer,
 377                                                         bgd[bg_idx].block_id))
 378                                         goto fail;
 379                                 prev_bg_bmap_idx = bg_idx;
 380                         }
 381                 }
 382
 383                 /* removing the parent double indirect block */
 384                 blknr = inode->b.blocks.double_indir_block;
 385                 if (fs->blksz != 1024) {
 386                         bg_idx = blknr / blk_per_grp;
 387                 } else {
 388                         bg_idx = blknr / blk_per_grp;
 389                         remainder = blknr % blk_per_grp;
 390                         if (!remainder)
 391                                 bg_idx--;
 392                 }
 393                 ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
 394                 bgd[bg_idx].free_blocks++;
 395                 fs->sb->free_blocks++;
 396                 /* journal backup */
 397                 if (prev_bg_bmap_idx != bg_idx) {
 398                         memset(journal_buffer, '\0', fs->blksz);
 399                         status = ext4fs_devread(bgd[bg_idx].block_id *
 400                                                 fs->sect_perblk, 0, fs->blksz,
 401                                                 journal_buffer);
 402                         if (status == 0)
 403                                 goto fail;
 404
 405                         if (ext4fs_log_journal(journal_buffer,
 406                                                 bgd[bg_idx].block_id))
 407                                 goto fail;
 408                         prev_bg_bmap_idx = bg_idx;
 409                 }
 410                 debug("DIPB releasing %ld\n", blknr);
 411         }
 412 fail:
 413         free(DIB_start_addr);
 414         free(journal_buffer);
 415 }
 416
 417 static void delete_triple_indirect_block(struct ext2_inode *inode)
 418 {
 419         int i, j;
 420         short status;
 421         static int prev_bg_bmap_idx = -1;
 422         long int blknr;
 423         int remainder;
 424         int bg_idx;
 425         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 426         unsigned int *tigp_buffer = NULL;
 427         unsigned int *tib_start_addr = NULL;
 428         unsigned int *tip_buffer = NULL;
 429         unsigned int *tipb_start_addr = NULL;
 430         struct ext2_block_group *bgd = NULL;
 431         struct ext_filesystem *fs = get_fs();
 432         char *journal_buffer = zalloc(fs->blksz);
 433         if (!journal_buffer) {
 434                 printf("No memory\n");
 435                 return;
 436         }
 437         /* get block group descriptor table */
 438         bgd = (struct ext2_block_group *)fs->gdtable;
 439
 440         if (inode->b.blocks.triple_indir_block != 0) {
 441                 tigp_buffer = zalloc(fs->blksz);
 442                 if (!tigp_buffer) {
 443                         printf("No memory\n");
 444                         return;
 445                 }
 446                 tib_start_addr = (unsigned int *)tigp_buffer;
 447                 blknr = inode->b.blocks.triple_indir_block;
 448                 status = ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
 449                                         (char *)tigp_buffer);
 450                 for (i = 0; i < fs->blksz / sizeof(int); i++) {
 451                         if (*tigp_buffer == 0)
 452                                 break;
 453                         debug("tigp buffer releasing %u\n", *tigp_buffer);
 454
 455                         tip_buffer = zalloc(fs->blksz);
 456                         if (!tip_buffer)
 457                                 goto fail;
 458                         tipb_start_addr = (unsigned int *)tip_buffer;
 459                         status = ext4fs_devread((*tigp_buffer) *
 460                                                 fs->sect_perblk, 0, fs->blksz,
 461                                                 (char *)tip_buffer);
 462                         for (j = 0; j < fs->blksz / sizeof(int); j++) {
 463                                 if (*tip_buffer == 0)
 464                                         break;
 465                                 if (fs->blksz != 1024) {
 466                                         bg_idx = (*tip_buffer) / blk_per_grp;
 467                                 } else {
 468                                         bg_idx = (*tip_buffer) / blk_per_grp;
 469
 470                                         remainder = (*tip_buffer) % blk_per_grp;
 471                                         if (!remainder)
 472                                                 bg_idx--;
 473                                 }
 474
 475                                 ext4fs_reset_block_bmap(*tip_buffer,
 476                                                         fs->blk_bmaps[bg_idx],
 477                                                         bg_idx);
 478
 479                                 tip_buffer++;
 480                                 bgd[bg_idx].free_blocks++;
 481                                 fs->sb->free_blocks++;
 482                                 /* journal backup */
 483                                 if (prev_bg_bmap_idx != bg_idx) {
 484                                         status =
 485                                             ext4fs_devread(
 486                                                         bgd[bg_idx].block_id *
 487                                                         fs->sect_perblk, 0,
 488                                                         fs->blksz,
 489                                                         journal_buffer);
 490                                         if (status == 0)
 491                                                 goto fail;
 492
 493                                         if (ext4fs_log_journal(journal_buffer,
 494                                                                bgd[bg_idx].
 495                                                                block_id))
 496                                                 goto fail;
 497                                         prev_bg_bmap_idx = bg_idx;
 498                                 }
 499                         }
 500                         free(tipb_start_addr);
 501                         tipb_start_addr = NULL;
 502
 503                         /*
 504                          * removing the grand parent blocks
 505                          * which is connected to inode
 506                          */
 507                         if (fs->blksz != 1024) {
 508                                 bg_idx = (*tigp_buffer) / blk_per_grp;
 509                         } else {
 510                                 bg_idx = (*tigp_buffer) / blk_per_grp;
 511
 512                                 remainder = (*tigp_buffer) % blk_per_grp;
 513                                 if (!remainder)
 514                                         bg_idx--;
 515                         }
 516                         ext4fs_reset_block_bmap(*tigp_buffer,
 517                                                 fs->blk_bmaps[bg_idx], bg_idx);
 518
 519                         tigp_buffer++;
 520                         bgd[bg_idx].free_blocks++;
 521                         fs->sb->free_blocks++;
 522                         /* journal backup */
 523                         if (prev_bg_bmap_idx != bg_idx) {
 524                                 memset(journal_buffer, '\0', fs->blksz);
 525                                 status =
 526                                     ext4fs_devread(bgd[bg_idx].block_id *
 527                                                    fs->sect_perblk, 0,
 528                                                    fs->blksz, journal_buffer);
 529                                 if (status == 0)
 530                                         goto fail;
 531
 532                                 if (ext4fs_log_journal(journal_buffer,
 533                                                         bgd[bg_idx].block_id))
 534                                         goto fail;
 535                                 prev_bg_bmap_idx = bg_idx;
 536                         }
 537                 }
 538
 539                 /* removing the grand parent triple indirect block */
 540                 blknr = inode->b.blocks.triple_indir_block;
 541                 if (fs->blksz != 1024) {
 542                         bg_idx = blknr / blk_per_grp;
 543                 } else {
 544                         bg_idx = blknr / blk_per_grp;
 545                         remainder = blknr % blk_per_grp;
 546                         if (!remainder)
 547                                 bg_idx--;
 548                 }
 549                 ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
 550                 bgd[bg_idx].free_blocks++;
 551                 fs->sb->free_blocks++;
 552                 /* journal backup */
 553                 if (prev_bg_bmap_idx != bg_idx) {
 554                         memset(journal_buffer, '\0', fs->blksz);
 555                         status = ext4fs_devread(bgd[bg_idx].block_id *
 556                                                 fs->sect_perblk, 0, fs->blksz,
 557                                                 journal_buffer);
 558                         if (status == 0)
 559                                 goto fail;
 560
 561                         if (ext4fs_log_journal(journal_buffer,
 562                                                 bgd[bg_idx].block_id))
 563                                 goto fail;
 564                         prev_bg_bmap_idx = bg_idx;
 565                 }
 566                 debug("tigp buffer itself releasing %ld\n", blknr);
 567         }
 568 fail:
 569         free(tib_start_addr);
 570         free(tipb_start_addr);
 571         free(journal_buffer);
 572 }
 573
 574 static int ext4fs_delete_file(int inodeno)
 575 {
 576         struct ext2_inode inode;
 577         short status;
 578         int i;
 579         int remainder;
 580         long int blknr;
 581         int bg_idx;
 582         int ibmap_idx;
 583         char *read_buffer = NULL;
 584         char *start_block_address = NULL;
 585         unsigned int no_blocks;
 586
 587         static int prev_bg_bmap_idx = -1;
 588         unsigned int inodes_per_block;
 589         long int blkno;
 590         unsigned int blkoff;
 591         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 592         unsigned int inode_per_grp = ext4fs_root->sblock.inodes_per_group;
 593         struct ext2_inode *inode_buffer = NULL;
 594         struct ext2_block_group *bgd = NULL;
 595         struct ext_filesystem *fs = get_fs();
 596         char *journal_buffer = zalloc(fs->blksz);
 597         if (!journal_buffer)
 598                 return -ENOMEM;
 599         /* get the block group descriptor table */
 600         bgd = (struct ext2_block_group *)fs->gdtable;
 601         status = ext4fs_read_inode(ext4fs_root, inodeno, &inode);
 602         if (status == 0)
 603                 goto fail;
 604
 605         /* read the block no allocated to a file */
 606         no_blocks = inode.size / fs->blksz;
 607         if (inode.size % fs->blksz)
 608                 no_blocks++;
 609
 610         if (le32_to_cpu(inode.flags) & EXT4_EXTENTS_FL) {
 611                 struct ext2fs_node *node_inode =
 612                     zalloc(sizeof(struct ext2fs_node));
 613                 if (!node_inode)
 614                         goto fail;
 615                 node_inode->data = ext4fs_root;
 616                 node_inode->ino = inodeno;
 617                 node_inode->inode_read = 0;
 618                 memcpy(&(node_inode->inode), &inode, sizeof(struct ext2_inode));
 619
 620                 for (i = 0; i < no_blocks; i++) {
 621                         blknr = read_allocated_block(&(node_inode->inode), i);
 622                         if (fs->blksz != 1024) {
 623                                 bg_idx = blknr / blk_per_grp;
 624                         } else {
 625                                 bg_idx = blknr / blk_per_grp;
 626                                 remainder = blknr % blk_per_grp;
 627                                 if (!remainder)
 628                                         bg_idx--;
 629                         }
 630                         ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx],
 631                                                 bg_idx);
 632                         debug("EXT4_EXTENTS Block releasing %ld: %d\n",
 633                               blknr, bg_idx);
 634
 635                         bgd[bg_idx].free_blocks++;
 636                         fs->sb->free_blocks++;
 637
 638                         /* journal backup */
 639                         if (prev_bg_bmap_idx != bg_idx) {
 640                                 status =
 641                                     ext4fs_devread(bgd[bg_idx].block_id *
 642                                                    fs->sect_perblk, 0,
 643                                                    fs->blksz, journal_buffer);
 644                                 if (status == 0)
 645                                         goto fail;
 646                                 if (ext4fs_log_journal(journal_buffer,
 647                                                         bgd[bg_idx].block_id))
 648                                         goto fail;
 649                                 prev_bg_bmap_idx = bg_idx;
 650                         }
 651                 }
 652                 if (node_inode) {
 653                         free(node_inode);
 654                         node_inode = NULL;
 655                 }
 656         } else {
 657
 658                 delete_single_indirect_block(&inode);
 659                 delete_double_indirect_block(&inode);
 660                 delete_triple_indirect_block(&inode);
 661
 662                 /* read the block no allocated to a file */
 663                 no_blocks = inode.size / fs->blksz;
 664                 if (inode.size % fs->blksz)
 665                         no_blocks++;
 666                 for (i = 0; i < no_blocks; i++) {
 667                         blknr = read_allocated_block(&inode, i);
 668                         if (fs->blksz != 1024) {
 669                                 bg_idx = blknr / blk_per_grp;
 670                         } else {
 671                                 bg_idx = blknr / blk_per_grp;
 672                                 remainder = blknr % blk_per_grp;
 673                                 if (!remainder)
 674                                         bg_idx--;
 675                         }
 676                         ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx],
 677                                                 bg_idx);
 678                         debug("ActualB releasing %ld: %d\n", blknr, bg_idx);
 679
 680                         bgd[bg_idx].free_blocks++;
 681                         fs->sb->free_blocks++;
 682                         /* journal backup */
 683                         if (prev_bg_bmap_idx != bg_idx) {
 684                                 memset(journal_buffer, '\0', fs->blksz);
 685                                 status = ext4fs_devread(bgd[bg_idx].block_id
 686                                                         * fs->sect_perblk,
 687                                                         0, fs->blksz,
 688                                                         journal_buffer);
 689                                 if (status == 0)
 690                                         goto fail;
 691                                 if (ext4fs_log_journal(journal_buffer,
 692                                                 bgd[bg_idx].block_id))
 693                                         goto fail;
 694                                 prev_bg_bmap_idx = bg_idx;
 695                         }
 696                 }
 697         }
 698
 699         /* from the inode no to blockno */
 700         inodes_per_block = fs->blksz / fs->inodesz;
 701         ibmap_idx = inodeno / inode_per_grp;
 702
 703         /* get the block no */
 704         inodeno--;
 705         blkno = __le32_to_cpu(bgd[ibmap_idx].inode_table_id) +
 706                 (inodeno % __le32_to_cpu(inode_per_grp)) / inodes_per_block;
 707
 708         /* get the offset of the inode */
 709         blkoff = ((inodeno) % inodes_per_block) * fs->inodesz;
 710
 711         /* read the block no containing the inode */
 712         read_buffer = zalloc(fs->blksz);
 713         if (!read_buffer)
 714                 goto fail;
 715         start_block_address = read_buffer;
 716         status = ext4fs_devread(blkno * fs->sect_perblk,
 717                                 0, fs->blksz, read_buffer);
 718         if (status == 0)
 719                 goto fail;
 720
 721         if (ext4fs_log_journal(read_buffer, blkno))
 722                 goto fail;
 723
 724         read_buffer = read_buffer + blkoff;
 725         inode_buffer = (struct ext2_inode *)read_buffer;
 726         memset(inode_buffer, '\0', sizeof(struct ext2_inode));
 727
 728         /* write the inode to original position in inode table */
 729         if (ext4fs_put_metadata(start_block_address, blkno))
 730                 goto fail;
 731
 732         /* update the respective inode bitmaps */
 733         inodeno++;
 734         ext4fs_reset_inode_bmap(inodeno, fs->inode_bmaps[ibmap_idx], ibmap_idx);
 735         bgd[ibmap_idx].free_inodes++;
 736         fs->sb->free_inodes++;
 737         /* journal backup */
 738         memset(journal_buffer, '\0', fs->blksz);
 739         status = ext4fs_devread(bgd[ibmap_idx].inode_id *
 740                                 fs->sect_perblk, 0, fs->blksz, journal_buffer);
 741         if (status == 0)
 742                 goto fail;
 743         if (ext4fs_log_journal(journal_buffer, bgd[ibmap_idx].inode_id))
 744                 goto fail;
 745
 746         ext4fs_update();
 747         ext4fs_deinit();
 748
 749         if (ext4fs_init() != 0) {
 750                 printf("error in File System init\n");
 751                 goto fail;
 752         }
 753
 754         free(start_block_address);
 755         free(journal_buffer);
 756
 757         return 0;
 758 fail:
 759         free(start_block_address);
 760         free(journal_buffer);
 761
 762         return -1;
 763 }
 764
 765 int ext4fs_init(void)
 766 {
 767         short status;
 768         int i;
 769         unsigned int real_free_blocks = 0;
 770         struct ext_filesystem *fs = get_fs();
 771
 772         /* populate fs */
 773         fs->blksz = EXT2_BLOCK_SIZE(ext4fs_root);
 774         fs->inodesz = INODE_SIZE_FILESYSTEM(ext4fs_root);
 775         fs->sect_perblk = fs->blksz / SECTOR_SIZE;
 776
 777         /* get the superblock */
 778         fs->sb = zalloc(SUPERBLOCK_SIZE);
 779         if (!fs->sb)
 780                 return -ENOMEM;
 781         if (!ext4fs_devread(SUPERBLOCK_SECTOR, 0, SUPERBLOCK_SIZE,
 782                         (char *)fs->sb))
 783                 goto fail;
 784
 785         /* init journal */
 786         if (ext4fs_init_journal())
 787                 goto fail;
 788
 789         /* get total no of blockgroups */
 790         fs->no_blkgrp = (uint32_t)ext4fs_div_roundup(
 791                         (ext4fs_root->sblock.total_blocks -
 792                         ext4fs_root->sblock.first_data_block),
 793                         ext4fs_root->sblock.blocks_per_group);
 794
 795         /* get the block group descriptor table */
 796         fs->gdtable_blkno = ((EXT2_MIN_BLOCK_SIZE == fs->blksz) + 1);
 797         if (ext4fs_get_bgdtable() == -1) {
 798                 printf("Error in getting the block group descriptor table\n");
 799                 goto fail;
 800         }
 801         fs->bgd = (struct ext2_block_group *)fs->gdtable;
 802
 803         /* load all the available bitmap block of the partition */
 804         fs->blk_bmaps = zalloc(fs->no_blkgrp * sizeof(char *));
 805         if (!fs->blk_bmaps)
 806                 goto fail;
 807         for (i = 0; i < fs->no_blkgrp; i++) {
 808                 fs->blk_bmaps[i] = zalloc(fs->blksz);
 809                 if (!fs->blk_bmaps[i])
 810                         goto fail;
 811         }
 812
 813         for (i = 0; i < fs->no_blkgrp; i++) {
 814                 status =
 815                     ext4fs_devread(fs->bgd[i].block_id * fs->sect_perblk, 0,
 816                                    fs->blksz, (char *)fs->blk_bmaps[i]);
 817                 if (status == 0)
 818                         goto fail;
 819         }
 820
 821         /* load all the available inode bitmap of the partition */
 822         fs->inode_bmaps = zalloc(fs->no_blkgrp * sizeof(unsigned char *));
 823         if (!fs->inode_bmaps)
 824                 goto fail;
 825         for (i = 0; i < fs->no_blkgrp; i++) {
 826                 fs->inode_bmaps[i] = zalloc(fs->blksz);
 827                 if (!fs->inode_bmaps[i])
 828                         goto fail;
 829         }
 830
 831         for (i = 0; i < fs->no_blkgrp; i++) {
 832                 status = ext4fs_devread(fs->bgd[i].inode_id * fs->sect_perblk,
 833                                         0, fs->blksz,
 834                                         (char *)fs->inode_bmaps[i]);
 835                 if (status == 0)
 836                         goto fail;
 837         }
 838
 839         /*
 840          * check filesystem consistency with free blocks of file system
 841          * some time we observed that superblock freeblocks does not match
 842          * with the  blockgroups freeblocks when improper
 843          * reboot of a linux kernel
 844          */
 845         for (i = 0; i < fs->no_blkgrp; i++)
 846                 real_free_blocks = real_free_blocks + fs->bgd[i].free_blocks;
 847         if (real_free_blocks != fs->sb->free_blocks)
 848                 fs->sb->free_blocks = real_free_blocks;
 849
 850         return 0;
 851 fail:
 852         ext4fs_deinit();
 853
 854         return -1;
 855 }
 856
 857 void ext4fs_deinit(void)
 858 {
 859         int i;
 860         struct ext2_inode inode_journal;
 861         struct journal_superblock_t *jsb;
 862         long int blknr;
 863         struct ext_filesystem *fs = get_fs();
 864
 865         /* free journal */
 866         char *temp_buff = zalloc(fs->blksz);
 867         if (temp_buff) {
 868                 ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO,
 869                                   &inode_journal);
 870                 blknr = read_allocated_block(&inode_journal,
 871                                         EXT2_JOURNAL_SUPERBLOCK);
 872                 ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
 873                                temp_buff);
 874                 jsb = (struct journal_superblock_t *)temp_buff;
 875                 jsb->s_start = cpu_to_be32(0);
 876                 put_ext4((uint64_t) (blknr * fs->blksz),
 877                          (struct journal_superblock_t *)temp_buff, fs->blksz);
 878                 free(temp_buff);
 879         }
 880         ext4fs_free_journal();
 881
 882         /* get the superblock */
 883         ext4fs_devread(SUPERBLOCK_SECTOR, 0, SUPERBLOCK_SIZE, (char *)fs->sb);
 884         fs->sb->feature_incompat &= ~EXT3_FEATURE_INCOMPAT_RECOVER;
 885         put_ext4((uint64_t)(SUPERBLOCK_SIZE),
 886                  (struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
 887         free(fs->sb);
 888         fs->sb = NULL;
 889
 890         if (fs->blk_bmaps) {
 891                 for (i = 0; i < fs->no_blkgrp; i++) {
 892                         free(fs->blk_bmaps[i]);
 893                         fs->blk_bmaps[i] = NULL;
 894                 }
 895                 free(fs->blk_bmaps);
 896                 fs->blk_bmaps = NULL;
 897         }
 898
 899         if (fs->inode_bmaps) {
 900                 for (i = 0; i < fs->no_blkgrp; i++) {
 901                         free(fs->inode_bmaps[i]);
 902                         fs->inode_bmaps[i] = NULL;
 903                 }
 904                 free(fs->inode_bmaps);
 905                 fs->inode_bmaps = NULL;
 906         }
 907
 908
 909         free(fs->gdtable);
 910         fs->gdtable = NULL;
 911         fs->bgd = NULL;
 912         /*
 913          * reinitiliazed the global inode and
 914          * block bitmap first execution check variables
 915          */
 916         fs->first_pass_ibmap = 0;
 917         fs->first_pass_bbmap = 0;
 918         fs->curr_inode_no = 0;
 919         fs->curr_blkno = 0;
 920 }
 921
 922 static int ext4fs_write_file(struct ext2_inode *file_inode,
 923                              int pos, unsigned int len, char *buf)
 924 {
 925         int i;
 926         int blockcnt;
 927         int log2blocksize = LOG2_EXT2_BLOCK_SIZE(ext4fs_root);
 928         unsigned int filesize = __le32_to_cpu(file_inode->size);
 929         struct ext_filesystem *fs = get_fs();
 930         int previous_block_number = -1;
 931         int delayed_start = 0;
 932         int delayed_extent = 0;
 933         int delayed_skipfirst = 0;
 934         int delayed_next = 0;
 935         char *delayed_buf = NULL;
 936
 937         /* Adjust len so it we can't read past the end of the file. */
 938         if (len > filesize)
 939                 len = filesize;
 940
 941         blockcnt = ((len + pos) + fs->blksz - 1) / fs->blksz;
 942
 943         for (i = pos / fs->blksz; i < blockcnt; i++) {
 944                 long int blknr;
 945                 int blockend = fs->blksz;
 946                 int skipfirst = 0;
 947                 blknr = read_allocated_block(file_inode, i);
 948                 if (blknr < 0)
 949                         return -1;
 950
 951                 blknr = blknr << log2blocksize;
 952
 953                 if (blknr) {
 954                         if (previous_block_number != -1) {
 955                                 if (delayed_next == blknr) {
 956                                         delayed_extent += blockend;
 957                                         delayed_next += blockend >> SECTOR_BITS;
 958                                 } else {        /* spill */
 959                                         put_ext4((uint64_t) (delayed_start *
 960                                                              SECTOR_SIZE),
 961                                                  delayed_buf,
 962                                                  (uint32_t) delayed_extent);
 963                                         previous_block_number = blknr;
 964                                         delayed_start = blknr;
 965                                         delayed_extent = blockend;
 966                                         delayed_skipfirst = skipfirst;
 967                                         delayed_buf = buf;
 968                                         delayed_next = blknr +
 969                                             (blockend >> SECTOR_BITS);
 970                                 }
 971                         } else {
 972                                 previous_block_number = blknr;
 973                                 delayed_start = blknr;
 974                                 delayed_extent = blockend;
 975                                 delayed_skipfirst = skipfirst;
 976                                 delayed_buf = buf;
 977                                 delayed_next = blknr +
 978                                     (blockend >> SECTOR_BITS);
 979                         }
 980                 } else {
 981                         if (previous_block_number != -1) {
 982                                 /* spill */
 983                                 put_ext4((uint64_t) (delayed_start *
 984                                                      SECTOR_SIZE), delayed_buf,
 985                                          (uint32_t) delayed_extent);
 986                                 previous_block_number = -1;
 987                         }
 988                         memset(buf, 0, fs->blksz - skipfirst);
 989                 }
 990                 buf += fs->blksz - skipfirst;
 991         }
 992         if (previous_block_number != -1) {
 993                 /* spill */
 994                 put_ext4((uint64_t) (delayed_start * SECTOR_SIZE),
 995                          delayed_buf, (uint32_t) delayed_extent);
 996                 previous_block_number = -1;
 997         }
 998
 999         return len;
1000 }
1001
1002 int ext4fs_write(const char *fname, unsigned char *buffer,
1003                                         unsigned long sizebytes)
1004 {
1005         int ret = 0;
1006         struct ext2_inode *file_inode = NULL;
1007         unsigned char *inode_buffer = NULL;
1008         int parent_inodeno;
1009         int inodeno;
1010         time_t timestamp = 0;
1011
1012         uint64_t bytes_reqd_for_file;
1013         unsigned int blks_reqd_for_file;
1014         unsigned int blocks_remaining;
1015         int existing_file_inodeno;
1016         char filename[256];
1017
1018         char *temp_ptr = NULL;
1019         long int itable_blkno;
1020         long int parent_itable_blkno;
1021         long int blkoff;
1022         struct ext2_sblock *sblock = &(ext4fs_root->sblock);
1023         unsigned int inodes_per_block;
1024         unsigned int ibmap_idx;
1025         struct ext_filesystem *fs = get_fs();
1026         g_parent_inode = zalloc(sizeof(struct ext2_inode));
1027         if (!g_parent_inode)
1028                 goto fail;
1029
1030         if (ext4fs_init() != 0) {
1031                 printf("error in File System init\n");
1032                 return -1;
1033         }
1034         inodes_per_block = fs->blksz / fs->inodesz;
1035         parent_inodeno = ext4fs_get_parent_inode_num(fname, filename, F_FILE);
1036         if (parent_inodeno == -1)
1037                 goto fail;
1038         if (ext4fs_iget(parent_inodeno, g_parent_inode))
1039                 goto fail;
1040         /* check if the filename is already present in root */
1041         existing_file_inodeno = ext4fs_filename_check(filename);
1042         if (existing_file_inodeno != -1) {
1043                 ret = ext4fs_delete_file(existing_file_inodeno);
1044                 fs->first_pass_bbmap = 0;
1045                 fs->curr_blkno = 0;
1046
1047                 fs->first_pass_ibmap = 0;
1048                 fs->curr_inode_no = 0;
1049                 if (ret)
1050                         goto fail;
1051         }
1052         /* calucalate how many blocks required */
1053         bytes_reqd_for_file = sizebytes;
1054         blks_reqd_for_file = bytes_reqd_for_file / fs->blksz;
1055         if (bytes_reqd_for_file % fs->blksz != 0) {
1056                 blks_reqd_for_file++;
1057                 debug("total bytes for a file %u\n", blks_reqd_for_file);
1058         }
1059         blocks_remaining = blks_reqd_for_file;
1060         /* test for available space in partition */
1061         if (fs->sb->free_blocks < blks_reqd_for_file) {
1062                 printf("Not enough space on partition !!!\n");
1063                 goto fail;
1064         }
1065
1066         ext4fs_update_parent_dentry(filename, &inodeno, FILETYPE_REG);
1067         /* prepare file inode */
1068         inode_buffer = zalloc(fs->inodesz);
1069         if (!inode_buffer)
1070                 goto fail;
1071         file_inode = (struct ext2_inode *)inode_buffer;
1072         file_inode->mode = S_IFREG | S_IRWXU |
1073             S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH;
1074         /* ToDo: Update correct time */
1075         file_inode->mtime = timestamp;
1076         file_inode->atime = timestamp;
1077         file_inode->ctime = timestamp;
1078         file_inode->nlinks = 1;
1079         file_inode->size = sizebytes;
1080
1081         /* Allocate data blocks */
1082         ext4fs_allocate_blocks(file_inode, blocks_remaining,
1083                                &blks_reqd_for_file);
1084         file_inode->blockcnt = (blks_reqd_for_file * fs->blksz) / SECTOR_SIZE;
1085
1086         temp_ptr = zalloc(fs->blksz);
1087         if (!temp_ptr)
1088                 goto fail;
1089         ibmap_idx = inodeno / ext4fs_root->sblock.inodes_per_group;
1090         inodeno--;
1091         itable_blkno = __le32_to_cpu(fs->bgd[ibmap_idx].inode_table_id) +
1092                         (inodeno % __le32_to_cpu(sblock->inodes_per_group)) /
1093                         inodes_per_block;
1094         blkoff = (inodeno % inodes_per_block) * fs->inodesz;
1095         ext4fs_devread(itable_blkno * fs->sect_perblk, 0, fs->blksz, temp_ptr);
1096         if (ext4fs_log_journal(temp_ptr, itable_blkno))
1097                 goto fail;
1098
1099         memcpy(temp_ptr + blkoff, inode_buffer, fs->inodesz);
1100         if (ext4fs_put_metadata(temp_ptr, itable_blkno))
1101                 goto fail;
1102         /* copy the file content into data blocks */
1103         if (ext4fs_write_file(file_inode, 0, sizebytes, (char *)buffer) == -1) {
1104                 printf("Error in copying content\n");
1105                 goto fail;
1106         }
1107         ibmap_idx = parent_inodeno / ext4fs_root->sblock.inodes_per_group;
1108         parent_inodeno--;
1109         parent_itable_blkno = __le32_to_cpu(fs->bgd[ibmap_idx].inode_table_id) +
1110             (parent_inodeno %
1111              __le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1112         blkoff = (parent_inodeno % inodes_per_block) * fs->inodesz;
1113         if (parent_itable_blkno != itable_blkno) {
1114                 memset(temp_ptr, '\0', fs->blksz);
1115                 ext4fs_devread(parent_itable_blkno * fs->sect_perblk,
1116                                0, fs->blksz, temp_ptr);
1117                 if (ext4fs_log_journal(temp_ptr, parent_itable_blkno))
1118                         goto fail;
1119
1120                 memcpy(temp_ptr + blkoff, g_parent_inode,
1121                         sizeof(struct ext2_inode));
1122                 if (ext4fs_put_metadata(temp_ptr, parent_itable_blkno))
1123                         goto fail;
1124                 free(temp_ptr);
1125         } else {
1126                 /*
1127                  * If parent and child fall in same inode table block
1128                  * both should be kept in 1 buffer
1129                  */
1130                 memcpy(temp_ptr + blkoff, g_parent_inode,
1131                        sizeof(struct ext2_inode));
1132                 gd_index--;
1133                 if (ext4fs_put_metadata(temp_ptr, itable_blkno))
1134                         goto fail;
1135                 free(temp_ptr);
1136         }
1137         ext4fs_update();
1138         ext4fs_deinit();
1139
1140         fs->first_pass_bbmap = 0;
1141         fs->curr_blkno = 0;
1142         fs->first_pass_ibmap = 0;
1143         fs->curr_inode_no = 0;
1144         free(inode_buffer);
1145         free(g_parent_inode);
1146         g_parent_inode = NULL;
1147
1148         return 0;
1149 fail:
1150         ext4fs_deinit();
1151         free(inode_buffer);
1152         free(g_parent_inode);
1153         g_parent_inode = NULL;
1154
1155         return -1;
1156 }
1157 #endif