fs/ext4/ext4_write.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  * SPDX-License-Identifier:     GPL-2.0+
  22  */
  23
  24
  25 #include <common.h>
  26 #include <linux/stat.h>
  27 #include <div64.h>
  28 #include "ext4_common.h"
  29
  30 static void ext4fs_update(void)
  31 {
  32         short i;
  33         ext4fs_update_journal();
  34         struct ext_filesystem *fs = get_fs();
  35
  36         /* update  super block */
  37         put_ext4((uint64_t)(SUPERBLOCK_SIZE),
  38                  (struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
  39
  40         /* update block groups */
  41         for (i = 0; i < fs->no_blkgrp; i++) {
  42                 fs->bgd[i].bg_checksum = ext4fs_checksum_update(i);
  43                 put_ext4((uint64_t)((uint64_t)fs->bgd[i].block_id * (uint64_t)fs->blksz),
  44                          fs->blk_bmaps[i], fs->blksz);
  45         }
  46
  47         /* update inode table groups */
  48         for (i = 0; i < fs->no_blkgrp; i++) {
  49                 put_ext4((uint64_t) ((uint64_t)fs->bgd[i].inode_id * (uint64_t)fs->blksz),
  50                          fs->inode_bmaps[i], fs->blksz);
  51         }
  52
  53         /* update the block group descriptor table */
  54         put_ext4((uint64_t)((uint64_t)fs->gdtable_blkno * (uint64_t)fs->blksz),
  55                  (struct ext2_block_group *)fs->gdtable,
  56                  (fs->blksz * fs->no_blk_pergdt));
  57
  58         ext4fs_dump_metadata();
  59
  60         gindex = 0;
  61         gd_index = 0;
  62 }
  63
  64 int ext4fs_get_bgdtable(void)
  65 {
  66         int status;
  67         int grp_desc_size;
  68         struct ext_filesystem *fs = get_fs();
  69         grp_desc_size = sizeof(struct ext2_block_group);
  70         fs->no_blk_pergdt = (fs->no_blkgrp * grp_desc_size) / fs->blksz;
  71         if ((fs->no_blkgrp * grp_desc_size) % fs->blksz)
  72                 fs->no_blk_pergdt++;
  73
  74         /* allocate memory for gdtable */
  75         fs->gdtable = zalloc(fs->blksz * fs->no_blk_pergdt);
  76         if (!fs->gdtable)
  77                 return -ENOMEM;
  78         /* read the group descriptor table */
  79         status = ext4fs_devread((lbaint_t)fs->gdtable_blkno * fs->sect_perblk,
  80                                 0, fs->blksz * fs->no_blk_pergdt, fs->gdtable);
  81         if (status == 0)
  82                 goto fail;
  83
  84         if (ext4fs_log_gdt(fs->gdtable)) {
  85                 printf("Error in ext4fs_log_gdt\n");
  86                 return -1;
  87         }
  88
  89         return 0;
  90 fail:
  91         free(fs->gdtable);
  92         fs->gdtable = NULL;
  93
  94         return -1;
  95 }
  96
  97 static void delete_single_indirect_block(struct ext2_inode *inode)
  98 {
  99         struct ext2_block_group *bgd = NULL;
 100         static int prev_bg_bmap_idx = -1;
 101         long int blknr;
 102         int remainder;
 103         int bg_idx;
 104         int status;
 105         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 106         struct ext_filesystem *fs = get_fs();
 107         char *journal_buffer = zalloc(fs->blksz);
 108         if (!journal_buffer) {
 109                 printf("No memory\n");
 110                 return;
 111         }
 112         /* get  block group descriptor table */
 113         bgd = (struct ext2_block_group *)fs->gdtable;
 114
 115         /* deleting the single indirect block associated with inode */
 116         if (inode->b.blocks.indir_block != 0) {
 117                 debug("SIPB releasing %u\n", inode->b.blocks.indir_block);
 118                 blknr = inode->b.blocks.indir_block;
 119                 bg_idx = blknr / blk_per_grp;
 120                 if (fs->blksz == 1024) {
 121                         remainder = blknr % blk_per_grp;
 122                         if (!remainder)
 123                                 bg_idx--;
 124                 }
 125                 ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
 126                 bgd[bg_idx].free_blocks++;
 127                 fs->sb->free_blocks++;
 128                 /* journal backup */
 129                 if (prev_bg_bmap_idx != bg_idx) {
 130                         status =
 131                             ext4fs_devread((lbaint_t)bgd[bg_idx].block_id *
 132                                            fs->sect_perblk, 0, fs->blksz,
 133                                            journal_buffer);
 134                         if (status == 0)
 135                                 goto fail;
 136                         if (ext4fs_log_journal
 137                             (journal_buffer, bgd[bg_idx].block_id))
 138                                 goto fail;
 139                         prev_bg_bmap_idx = bg_idx;
 140                 }
 141         }
 142 fail:
 143         free(journal_buffer);
 144 }
 145
 146 static void delete_double_indirect_block(struct ext2_inode *inode)
 147 {
 148         int i;
 149         short status;
 150         static int prev_bg_bmap_idx = -1;
 151         long int blknr;
 152         int remainder;
 153         int bg_idx;
 154         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 155         unsigned int *di_buffer = NULL;
 156         unsigned int *DIB_start_addr = NULL;
 157         struct ext2_block_group *bgd = NULL;
 158         struct ext_filesystem *fs = get_fs();
 159         char *journal_buffer = zalloc(fs->blksz);
 160         if (!journal_buffer) {
 161                 printf("No memory\n");
 162                 return;
 163         }
 164         /* get the block group descriptor table */
 165         bgd = (struct ext2_block_group *)fs->gdtable;
 166
 167         if (inode->b.blocks.double_indir_block != 0) {
 168                 di_buffer = zalloc(fs->blksz);
 169                 if (!di_buffer) {
 170                         printf("No memory\n");
 171                         return;
 172                 }
 173                 DIB_start_addr = (unsigned int *)di_buffer;
 174                 blknr = inode->b.blocks.double_indir_block;
 175                 status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0,
 176                                         fs->blksz, (char *)di_buffer);
 177                 for (i = 0; i < fs->blksz / sizeof(int); i++) {
 178                         if (*di_buffer == 0)
 179                                 break;
 180
 181                         debug("DICB releasing %u\n", *di_buffer);
 182                         bg_idx = *di_buffer / blk_per_grp;
 183                         if (fs->blksz == 1024) {
 184                                 remainder = *di_buffer % blk_per_grp;
 185                                 if (!remainder)
 186                                         bg_idx--;
 187                         }
 188                         ext4fs_reset_block_bmap(*di_buffer,
 189                                         fs->blk_bmaps[bg_idx], bg_idx);
 190                         di_buffer++;
 191                         bgd[bg_idx].free_blocks++;
 192                         fs->sb->free_blocks++;
 193                         /* journal backup */
 194                         if (prev_bg_bmap_idx != bg_idx) {
 195                                 status = ext4fs_devread((lbaint_t)
 196                                                         bgd[bg_idx].block_id
 197                                                         * fs->sect_perblk, 0,
 198                                                         fs->blksz,
 199                                                         journal_buffer);
 200                                 if (status == 0)
 201                                         goto fail;
 202
 203                                 if (ext4fs_log_journal(journal_buffer,
 204                                                         bgd[bg_idx].block_id))
 205                                         goto fail;
 206                                 prev_bg_bmap_idx = bg_idx;
 207                         }
 208                 }
 209
 210                 /* removing the parent double indirect block */
 211                 blknr = inode->b.blocks.double_indir_block;
 212                 bg_idx = blknr / blk_per_grp;
 213                 if (fs->blksz == 1024) {
 214                         remainder = blknr % blk_per_grp;
 215                         if (!remainder)
 216                                 bg_idx--;
 217                 }
 218                 ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
 219                 bgd[bg_idx].free_blocks++;
 220                 fs->sb->free_blocks++;
 221                 /* journal backup */
 222                 if (prev_bg_bmap_idx != bg_idx) {
 223                         memset(journal_buffer, '\0', fs->blksz);
 224                         status = ext4fs_devread((lbaint_t)bgd[bg_idx].block_id *
 225                                                 fs->sect_perblk, 0, fs->blksz,
 226                                                 journal_buffer);
 227                         if (status == 0)
 228                                 goto fail;
 229
 230                         if (ext4fs_log_journal(journal_buffer,
 231                                                 bgd[bg_idx].block_id))
 232                                 goto fail;
 233                         prev_bg_bmap_idx = bg_idx;
 234                 }
 235                 debug("DIPB releasing %ld\n", blknr);
 236         }
 237 fail:
 238         free(DIB_start_addr);
 239         free(journal_buffer);
 240 }
 241
 242 static void delete_triple_indirect_block(struct ext2_inode *inode)
 243 {
 244         int i, j;
 245         short status;
 246         static int prev_bg_bmap_idx = -1;
 247         long int blknr;
 248         int remainder;
 249         int bg_idx;
 250         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 251         unsigned int *tigp_buffer = NULL;
 252         unsigned int *tib_start_addr = NULL;
 253         unsigned int *tip_buffer = NULL;
 254         unsigned int *tipb_start_addr = NULL;
 255         struct ext2_block_group *bgd = NULL;
 256         struct ext_filesystem *fs = get_fs();
 257         char *journal_buffer = zalloc(fs->blksz);
 258         if (!journal_buffer) {
 259                 printf("No memory\n");
 260                 return;
 261         }
 262         /* get block group descriptor table */
 263         bgd = (struct ext2_block_group *)fs->gdtable;
 264
 265         if (inode->b.blocks.triple_indir_block != 0) {
 266                 tigp_buffer = zalloc(fs->blksz);
 267                 if (!tigp_buffer) {
 268                         printf("No memory\n");
 269                         return;
 270                 }
 271                 tib_start_addr = (unsigned int *)tigp_buffer;
 272                 blknr = inode->b.blocks.triple_indir_block;
 273                 status = ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0,
 274                                         fs->blksz, (char *)tigp_buffer);
 275                 for (i = 0; i < fs->blksz / sizeof(int); i++) {
 276                         if (*tigp_buffer == 0)
 277                                 break;
 278                         debug("tigp buffer releasing %u\n", *tigp_buffer);
 279
 280                         tip_buffer = zalloc(fs->blksz);
 281                         if (!tip_buffer)
 282                                 goto fail;
 283                         tipb_start_addr = (unsigned int *)tip_buffer;
 284                         status = ext4fs_devread((lbaint_t)(*tigp_buffer) *
 285                                                 fs->sect_perblk, 0, fs->blksz,
 286                                                 (char *)tip_buffer);
 287                         for (j = 0; j < fs->blksz / sizeof(int); j++) {
 288                                 if (*tip_buffer == 0)
 289                                         break;
 290                                 bg_idx = *tip_buffer / blk_per_grp;
 291                                 if (fs->blksz == 1024) {
 292                                         remainder = *tip_buffer % blk_per_grp;
 293                                         if (!remainder)
 294                                                 bg_idx--;
 295                                 }
 296
 297                                 ext4fs_reset_block_bmap(*tip_buffer,
 298                                                         fs->blk_bmaps[bg_idx],
 299                                                         bg_idx);
 300
 301                                 tip_buffer++;
 302                                 bgd[bg_idx].free_blocks++;
 303                                 fs->sb->free_blocks++;
 304                                 /* journal backup */
 305                                 if (prev_bg_bmap_idx != bg_idx) {
 306                                         status =
 307                                             ext4fs_devread(
 308                                                         (lbaint_t)
 309                                                         bgd[bg_idx].block_id *
 310                                                         fs->sect_perblk, 0,
 311                                                         fs->blksz,
 312                                                         journal_buffer);
 313                                         if (status == 0)
 314                                                 goto fail;
 315
 316                                         if (ext4fs_log_journal(journal_buffer,
 317                                                                bgd[bg_idx].
 318                                                                block_id))
 319                                                 goto fail;
 320                                         prev_bg_bmap_idx = bg_idx;
 321                                 }
 322                         }
 323                         free(tipb_start_addr);
 324                         tipb_start_addr = NULL;
 325
 326                         /*
 327                          * removing the grand parent blocks
 328                          * which is connected to inode
 329                          */
 330                         bg_idx = *tigp_buffer / blk_per_grp;
 331                         if (fs->blksz == 1024) {
 332                                 remainder = *tigp_buffer % blk_per_grp;
 333                                 if (!remainder)
 334                                         bg_idx--;
 335                         }
 336                         ext4fs_reset_block_bmap(*tigp_buffer,
 337                                                 fs->blk_bmaps[bg_idx], bg_idx);
 338
 339                         tigp_buffer++;
 340                         bgd[bg_idx].free_blocks++;
 341                         fs->sb->free_blocks++;
 342                         /* journal backup */
 343                         if (prev_bg_bmap_idx != bg_idx) {
 344                                 memset(journal_buffer, '\0', fs->blksz);
 345                                 status =
 346                                     ext4fs_devread((lbaint_t)
 347                                                    bgd[bg_idx].block_id *
 348                                                    fs->sect_perblk, 0,
 349                                                    fs->blksz, journal_buffer);
 350                                 if (status == 0)
 351                                         goto fail;
 352
 353                                 if (ext4fs_log_journal(journal_buffer,
 354                                                         bgd[bg_idx].block_id))
 355                                         goto fail;
 356                                 prev_bg_bmap_idx = bg_idx;
 357                         }
 358                 }
 359
 360                 /* removing the grand parent triple indirect block */
 361                 blknr = inode->b.blocks.triple_indir_block;
 362                 bg_idx = blknr / blk_per_grp;
 363                 if (fs->blksz == 1024) {
 364                         remainder = blknr % blk_per_grp;
 365                         if (!remainder)
 366                                 bg_idx--;
 367                 }
 368                 ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
 369                 bgd[bg_idx].free_blocks++;
 370                 fs->sb->free_blocks++;
 371                 /* journal backup */
 372                 if (prev_bg_bmap_idx != bg_idx) {
 373                         memset(journal_buffer, '\0', fs->blksz);
 374                         status = ext4fs_devread((lbaint_t)bgd[bg_idx].block_id *
 375                                                 fs->sect_perblk, 0, fs->blksz,
 376                                                 journal_buffer);
 377                         if (status == 0)
 378                                 goto fail;
 379
 380                         if (ext4fs_log_journal(journal_buffer,
 381                                                 bgd[bg_idx].block_id))
 382                                 goto fail;
 383                         prev_bg_bmap_idx = bg_idx;
 384                 }
 385                 debug("tigp buffer itself releasing %ld\n", blknr);
 386         }
 387 fail:
 388         free(tib_start_addr);
 389         free(tipb_start_addr);
 390         free(journal_buffer);
 391 }
 392
 393 static int ext4fs_delete_file(int inodeno)
 394 {
 395         struct ext2_inode inode;
 396         short status;
 397         int i;
 398         int remainder;
 399         long int blknr;
 400         int bg_idx;
 401         int ibmap_idx;
 402         char *read_buffer = NULL;
 403         char *start_block_address = NULL;
 404         unsigned int no_blocks;
 405
 406         static int prev_bg_bmap_idx = -1;
 407         unsigned int inodes_per_block;
 408         long int blkno;
 409         unsigned int blkoff;
 410         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 411         unsigned int inode_per_grp = ext4fs_root->sblock.inodes_per_group;
 412         struct ext2_inode *inode_buffer = NULL;
 413         struct ext2_block_group *bgd = NULL;
 414         struct ext_filesystem *fs = get_fs();
 415         char *journal_buffer = zalloc(fs->blksz);
 416         if (!journal_buffer)
 417                 return -ENOMEM;
 418         /* get the block group descriptor table */
 419         bgd = (struct ext2_block_group *)fs->gdtable;
 420         status = ext4fs_read_inode(ext4fs_root, inodeno, &inode);
 421         if (status == 0)
 422                 goto fail;
 423
 424         /* read the block no allocated to a file */
 425         no_blocks = inode.size / fs->blksz;
 426         if (inode.size % fs->blksz)
 427                 no_blocks++;
 428
 429         if (le32_to_cpu(inode.flags) & EXT4_EXTENTS_FL) {
 430                 struct ext2fs_node *node_inode =
 431                     zalloc(sizeof(struct ext2fs_node));
 432                 if (!node_inode)
 433                         goto fail;
 434                 node_inode->data = ext4fs_root;
 435                 node_inode->ino = inodeno;
 436                 node_inode->inode_read = 0;
 437                 memcpy(&(node_inode->inode), &inode, sizeof(struct ext2_inode));
 438
 439                 for (i = 0; i < no_blocks; i++) {
 440                         blknr = read_allocated_block(&(node_inode->inode), i);
 441                         bg_idx = blknr / blk_per_grp;
 442                         if (fs->blksz == 1024) {
 443                                 remainder = blknr % blk_per_grp;
 444                                 if (!remainder)
 445                                         bg_idx--;
 446                         }
 447                         ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx],
 448                                                 bg_idx);
 449                         debug("EXT4_EXTENTS Block releasing %ld: %d\n",
 450                               blknr, bg_idx);
 451
 452                         bgd[bg_idx].free_blocks++;
 453                         fs->sb->free_blocks++;
 454
 455                         /* journal backup */
 456                         if (prev_bg_bmap_idx != bg_idx) {
 457                                 status =
 458                                     ext4fs_devread((lbaint_t)
 459                                                    bgd[bg_idx].block_id *
 460                                                    fs->sect_perblk, 0,
 461                                                    fs->blksz, journal_buffer);
 462                                 if (status == 0)
 463                                         goto fail;
 464                                 if (ext4fs_log_journal(journal_buffer,
 465                                                         bgd[bg_idx].block_id))
 466                                         goto fail;
 467                                 prev_bg_bmap_idx = bg_idx;
 468                         }
 469                 }
 470                 if (node_inode) {
 471                         free(node_inode);
 472                         node_inode = NULL;
 473                 }
 474         } else {
 475
 476                 delete_single_indirect_block(&inode);
 477                 delete_double_indirect_block(&inode);
 478                 delete_triple_indirect_block(&inode);
 479
 480                 /* read the block no allocated to a file */
 481                 no_blocks = inode.size / fs->blksz;
 482                 if (inode.size % fs->blksz)
 483                         no_blocks++;
 484                 for (i = 0; i < no_blocks; i++) {
 485                         blknr = read_allocated_block(&inode, i);
 486                         bg_idx = blknr / blk_per_grp;
 487                         if (fs->blksz == 1024) {
 488                                 remainder = blknr % blk_per_grp;
 489                                 if (!remainder)
 490                                         bg_idx--;
 491                         }
 492                         ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx],
 493                                                 bg_idx);
 494                         debug("ActualB releasing %ld: %d\n", blknr, bg_idx);
 495
 496                         bgd[bg_idx].free_blocks++;
 497                         fs->sb->free_blocks++;
 498                         /* journal backup */
 499                         if (prev_bg_bmap_idx != bg_idx) {
 500                                 memset(journal_buffer, '\0', fs->blksz);
 501                                 status = ext4fs_devread((lbaint_t)
 502                                                         bgd[bg_idx].block_id
 503                                                         * fs->sect_perblk,
 504                                                         0, fs->blksz,
 505                                                         journal_buffer);
 506                                 if (status == 0)
 507                                         goto fail;
 508                                 if (ext4fs_log_journal(journal_buffer,
 509                                                 bgd[bg_idx].block_id))
 510                                         goto fail;
 511                                 prev_bg_bmap_idx = bg_idx;
 512                         }
 513                 }
 514         }
 515
 516         /* from the inode no to blockno */
 517         inodes_per_block = fs->blksz / fs->inodesz;
 518         ibmap_idx = inodeno / inode_per_grp;
 519
 520         /* get the block no */
 521         inodeno--;
 522         blkno = __le32_to_cpu(bgd[ibmap_idx].inode_table_id) +
 523                 (inodeno % __le32_to_cpu(inode_per_grp)) / inodes_per_block;
 524
 525         /* get the offset of the inode */
 526         blkoff = ((inodeno) % inodes_per_block) * fs->inodesz;
 527
 528         /* read the block no containing the inode */
 529         read_buffer = zalloc(fs->blksz);
 530         if (!read_buffer)
 531                 goto fail;
 532         start_block_address = read_buffer;
 533         status = ext4fs_devread((lbaint_t)blkno * fs->sect_perblk,
 534                                 0, fs->blksz, read_buffer);
 535         if (status == 0)
 536                 goto fail;
 537
 538         if (ext4fs_log_journal(read_buffer, blkno))
 539                 goto fail;
 540
 541         read_buffer = read_buffer + blkoff;
 542         inode_buffer = (struct ext2_inode *)read_buffer;
 543         memset(inode_buffer, '\0', sizeof(struct ext2_inode));
 544
 545         /* write the inode to original position in inode table */
 546         if (ext4fs_put_metadata(start_block_address, blkno))
 547                 goto fail;
 548
 549         /* update the respective inode bitmaps */
 550         inodeno++;
 551         ext4fs_reset_inode_bmap(inodeno, fs->inode_bmaps[ibmap_idx], ibmap_idx);
 552         bgd[ibmap_idx].free_inodes++;
 553         fs->sb->free_inodes++;
 554         /* journal backup */
 555         memset(journal_buffer, '\0', fs->blksz);
 556         status = ext4fs_devread((lbaint_t)bgd[ibmap_idx].inode_id *
 557                                 fs->sect_perblk, 0, fs->blksz, journal_buffer);
 558         if (status == 0)
 559                 goto fail;
 560         if (ext4fs_log_journal(journal_buffer, bgd[ibmap_idx].inode_id))
 561                 goto fail;
 562
 563         ext4fs_update();
 564         ext4fs_deinit();
 565         ext4fs_reinit_global();
 566
 567         if (ext4fs_init() != 0) {
 568                 printf("error in File System init\n");
 569                 goto fail;
 570         }
 571
 572         free(start_block_address);
 573         free(journal_buffer);
 574
 575         return 0;
 576 fail:
 577         free(start_block_address);
 578         free(journal_buffer);
 579
 580         return -1;
 581 }
 582
 583 int ext4fs_init(void)
 584 {
 585         short status;
 586         int i;
 587         unsigned int real_free_blocks = 0;
 588         struct ext_filesystem *fs = get_fs();
 589
 590         /* populate fs */
 591         fs->blksz = EXT2_BLOCK_SIZE(ext4fs_root);
 592         fs->inodesz = INODE_SIZE_FILESYSTEM(ext4fs_root);
 593         fs->sect_perblk = fs->blksz >> fs->dev_desc->log2blksz;
 594
 595         /* get the superblock */
 596         fs->sb = zalloc(SUPERBLOCK_SIZE);
 597         if (!fs->sb)
 598                 return -ENOMEM;
 599         if (!ext4_read_superblock((char *)fs->sb))
 600                 goto fail;
 601
 602         /* init journal */
 603         if (ext4fs_init_journal())
 604                 goto fail;
 605
 606         /* get total no of blockgroups */
 607         fs->no_blkgrp = (uint32_t)ext4fs_div_roundup(
 608                         (ext4fs_root->sblock.total_blocks -
 609                         ext4fs_root->sblock.first_data_block),
 610                         ext4fs_root->sblock.blocks_per_group);
 611
 612         /* get the block group descriptor table */
 613         fs->gdtable_blkno = ((EXT2_MIN_BLOCK_SIZE == fs->blksz) + 1);
 614         if (ext4fs_get_bgdtable() == -1) {
 615                 printf("Error in getting the block group descriptor table\n");
 616                 goto fail;
 617         }
 618         fs->bgd = (struct ext2_block_group *)fs->gdtable;
 619
 620         /* load all the available bitmap block of the partition */
 621         fs->blk_bmaps = zalloc(fs->no_blkgrp * sizeof(char *));
 622         if (!fs->blk_bmaps)
 623                 goto fail;
 624         for (i = 0; i < fs->no_blkgrp; i++) {
 625                 fs->blk_bmaps[i] = zalloc(fs->blksz);
 626                 if (!fs->blk_bmaps[i])
 627                         goto fail;
 628         }
 629
 630         for (i = 0; i < fs->no_blkgrp; i++) {
 631                 status =
 632                     ext4fs_devread((lbaint_t)fs->bgd[i].block_id *
 633                                    fs->sect_perblk, 0,
 634                                    fs->blksz, (char *)fs->blk_bmaps[i]);
 635                 if (status == 0)
 636                         goto fail;
 637         }
 638
 639         /* load all the available inode bitmap of the partition */
 640         fs->inode_bmaps = zalloc(fs->no_blkgrp * sizeof(unsigned char *));
 641         if (!fs->inode_bmaps)
 642                 goto fail;
 643         for (i = 0; i < fs->no_blkgrp; i++) {
 644                 fs->inode_bmaps[i] = zalloc(fs->blksz);
 645                 if (!fs->inode_bmaps[i])
 646                         goto fail;
 647         }
 648
 649         for (i = 0; i < fs->no_blkgrp; i++) {
 650                 status = ext4fs_devread((lbaint_t)fs->bgd[i].inode_id *
 651                                         fs->sect_perblk,
 652                                         0, fs->blksz,
 653                                         (char *)fs->inode_bmaps[i]);
 654                 if (status == 0)
 655                         goto fail;
 656         }
 657
 658         /*
 659          * check filesystem consistency with free blocks of file system
 660          * some time we observed that superblock freeblocks does not match
 661          * with the  blockgroups freeblocks when improper
 662          * reboot of a linux kernel
 663          */
 664         for (i = 0; i < fs->no_blkgrp; i++)
 665                 real_free_blocks = real_free_blocks + fs->bgd[i].free_blocks;
 666         if (real_free_blocks != fs->sb->free_blocks)
 667                 fs->sb->free_blocks = real_free_blocks;
 668
 669         return 0;
 670 fail:
 671         ext4fs_deinit();
 672
 673         return -1;
 674 }
 675
 676 void ext4fs_deinit(void)
 677 {
 678         int i;
 679         struct ext2_inode inode_journal;
 680         struct journal_superblock_t *jsb;
 681         long int blknr;
 682         struct ext_filesystem *fs = get_fs();
 683
 684         /* free journal */
 685         char *temp_buff = zalloc(fs->blksz);
 686         if (temp_buff) {
 687                 ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO,
 688                                   &inode_journal);
 689                 blknr = read_allocated_block(&inode_journal,
 690                                         EXT2_JOURNAL_SUPERBLOCK);
 691                 ext4fs_devread((lbaint_t)blknr * fs->sect_perblk, 0, fs->blksz,
 692                                temp_buff);
 693                 jsb = (struct journal_superblock_t *)temp_buff;
 694                 jsb->s_start = cpu_to_be32(0);
 695                 put_ext4((uint64_t) ((uint64_t)blknr * (uint64_t)fs->blksz),
 696                          (struct journal_superblock_t *)temp_buff, fs->blksz);
 697                 free(temp_buff);
 698         }
 699         ext4fs_free_journal();
 700
 701         /* get the superblock */
 702         ext4_read_superblock((char *)fs->sb);
 703         fs->sb->feature_incompat &= ~EXT3_FEATURE_INCOMPAT_RECOVER;
 704         put_ext4((uint64_t)(SUPERBLOCK_SIZE),
 705                  (struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
 706         free(fs->sb);
 707         fs->sb = NULL;
 708
 709         if (fs->blk_bmaps) {
 710                 for (i = 0; i < fs->no_blkgrp; i++) {
 711                         free(fs->blk_bmaps[i]);
 712                         fs->blk_bmaps[i] = NULL;
 713                 }
 714                 free(fs->blk_bmaps);
 715                 fs->blk_bmaps = NULL;
 716         }
 717
 718         if (fs->inode_bmaps) {
 719                 for (i = 0; i < fs->no_blkgrp; i++) {
 720                         free(fs->inode_bmaps[i]);
 721                         fs->inode_bmaps[i] = NULL;
 722                 }
 723                 free(fs->inode_bmaps);
 724                 fs->inode_bmaps = NULL;
 725         }
 726
 727
 728         free(fs->gdtable);
 729         fs->gdtable = NULL;
 730         fs->bgd = NULL;
 731         /*
 732          * reinitiliazed the global inode and
 733          * block bitmap first execution check variables
 734          */
 735         fs->first_pass_ibmap = 0;
 736         fs->first_pass_bbmap = 0;
 737         fs->curr_inode_no = 0;
 738         fs->curr_blkno = 0;
 739 }
 740
 741 static int ext4fs_write_file(struct ext2_inode *file_inode,
 742                              int pos, unsigned int len, char *buf)
 743 {
 744         int i;
 745         int blockcnt;
 746         unsigned int filesize = __le32_to_cpu(file_inode->size);
 747         struct ext_filesystem *fs = get_fs();
 748         int log2blksz = fs->dev_desc->log2blksz;
 749         int log2_fs_blocksize = LOG2_BLOCK_SIZE(ext4fs_root) - log2blksz;
 750         int previous_block_number = -1;
 751         int delayed_start = 0;
 752         int delayed_extent = 0;
 753         int delayed_next = 0;
 754         char *delayed_buf = NULL;
 755
 756         /* Adjust len so it we can't read past the end of the file. */
 757         if (len > filesize)
 758                 len = filesize;
 759
 760         blockcnt = ((len + pos) + fs->blksz - 1) / fs->blksz;
 761
 762         for (i = pos / fs->blksz; i < blockcnt; i++) {
 763                 long int blknr;
 764                 int blockend = fs->blksz;
 765                 int skipfirst = 0;
 766                 blknr = read_allocated_block(file_inode, i);
 767                 if (blknr < 0)
 768                         return -1;
 769
 770                 blknr = blknr << log2_fs_blocksize;
 771
 772                 if (blknr) {
 773                         if (previous_block_number != -1) {
 774                                 if (delayed_next == blknr) {
 775                                         delayed_extent += blockend;
 776                                         delayed_next += blockend >> log2blksz;
 777                                 } else {        /* spill */
 778                                         put_ext4((uint64_t)
 779                                                  ((uint64_t)delayed_start << log2blksz),
 780                                                  delayed_buf,
 781                                                  (uint32_t) delayed_extent);
 782                                         previous_block_number = blknr;
 783                                         delayed_start = blknr;
 784                                         delayed_extent = blockend;
 785                                         delayed_buf = buf;
 786                                         delayed_next = blknr +
 787                                             (blockend >> log2blksz);
 788                                 }
 789                         } else {
 790                                 previous_block_number = blknr;
 791                                 delayed_start = blknr;
 792                                 delayed_extent = blockend;
 793                                 delayed_buf = buf;
 794                                 delayed_next = blknr +
 795                                     (blockend >> log2blksz);
 796                         }
 797                 } else {
 798                         if (previous_block_number != -1) {
 799                                 /* spill */
 800                                 put_ext4((uint64_t) ((uint64_t)delayed_start <<
 801                                                      log2blksz),
 802                                          delayed_buf,
 803                                          (uint32_t) delayed_extent);
 804                                 previous_block_number = -1;
 805                         }
 806                         memset(buf, 0, fs->blksz - skipfirst);
 807                 }
 808                 buf += fs->blksz - skipfirst;
 809         }
 810         if (previous_block_number != -1) {
 811                 /* spill */
 812                 put_ext4((uint64_t) ((uint64_t)delayed_start << log2blksz),
 813                          delayed_buf, (uint32_t) delayed_extent);
 814                 previous_block_number = -1;
 815         }
 816
 817         return len;
 818 }
 819
 820 int ext4fs_write(const char *fname, unsigned char *buffer,
 821                                         unsigned long sizebytes)
 822 {
 823         int ret = 0;
 824         struct ext2_inode *file_inode = NULL;
 825         unsigned char *inode_buffer = NULL;
 826         int parent_inodeno;
 827         int inodeno;
 828         time_t timestamp = 0;
 829
 830         uint64_t bytes_reqd_for_file;
 831         unsigned int blks_reqd_for_file;
 832         unsigned int blocks_remaining;
 833         int existing_file_inodeno;
 834         char *temp_ptr = NULL;
 835         long int itable_blkno;
 836         long int parent_itable_blkno;
 837         long int blkoff;
 838         struct ext2_sblock *sblock = &(ext4fs_root->sblock);
 839         unsigned int inodes_per_block;
 840         unsigned int ibmap_idx;
 841         struct ext_filesystem *fs = get_fs();
 842         ALLOC_CACHE_ALIGN_BUFFER(char, filename, 256);
 843         memset(filename, 0x00, 256);
 844
 845         g_parent_inode = zalloc(sizeof(struct ext2_inode));
 846         if (!g_parent_inode)
 847                 goto fail;
 848
 849         if (ext4fs_init() != 0) {
 850                 printf("error in File System init\n");
 851                 return -1;
 852         }
 853         inodes_per_block = fs->blksz / fs->inodesz;
 854         parent_inodeno = ext4fs_get_parent_inode_num(fname, filename, F_FILE);
 855         if (parent_inodeno == -1)
 856                 goto fail;
 857         if (ext4fs_iget(parent_inodeno, g_parent_inode))
 858                 goto fail;
 859         /* check if the filename is already present in root */
 860         existing_file_inodeno = ext4fs_filename_check(filename);
 861         if (existing_file_inodeno != -1) {
 862                 ret = ext4fs_delete_file(existing_file_inodeno);
 863                 fs->first_pass_bbmap = 0;
 864                 fs->curr_blkno = 0;
 865
 866                 fs->first_pass_ibmap = 0;
 867                 fs->curr_inode_no = 0;
 868                 if (ret)
 869                         goto fail;
 870         }
 871         /* calucalate how many blocks required */
 872         bytes_reqd_for_file = sizebytes;
 873         blks_reqd_for_file = lldiv(bytes_reqd_for_file, fs->blksz);
 874         if (do_div(bytes_reqd_for_file, fs->blksz) != 0) {
 875                 blks_reqd_for_file++;
 876                 debug("total bytes for a file %u\n", blks_reqd_for_file);
 877         }
 878         blocks_remaining = blks_reqd_for_file;
 879         /* test for available space in partition */
 880         if (fs->sb->free_blocks < blks_reqd_for_file) {
 881                 printf("Not enough space on partition !!!\n");
 882                 goto fail;
 883         }
 884
 885         ext4fs_update_parent_dentry(filename, &inodeno, FILETYPE_REG);
 886         /* prepare file inode */
 887         inode_buffer = zalloc(fs->inodesz);
 888         if (!inode_buffer)
 889                 goto fail;
 890         file_inode = (struct ext2_inode *)inode_buffer;
 891         file_inode->mode = S_IFREG | S_IRWXU |
 892             S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH;
 893         /* ToDo: Update correct time */
 894         file_inode->mtime = timestamp;
 895         file_inode->atime = timestamp;
 896         file_inode->ctime = timestamp;
 897         file_inode->nlinks = 1;
 898         file_inode->size = sizebytes;
 899
 900         /* Allocate data blocks */
 901         ext4fs_allocate_blocks(file_inode, blocks_remaining,
 902                                &blks_reqd_for_file);
 903         file_inode->blockcnt = (blks_reqd_for_file * fs->blksz) >>
 904                 fs->dev_desc->log2blksz;
 905
 906         temp_ptr = zalloc(fs->blksz);
 907         if (!temp_ptr)
 908                 goto fail;
 909         ibmap_idx = inodeno / ext4fs_root->sblock.inodes_per_group;
 910         inodeno--;
 911         itable_blkno = __le32_to_cpu(fs->bgd[ibmap_idx].inode_table_id) +
 912                         (inodeno % __le32_to_cpu(sblock->inodes_per_group)) /
 913                         inodes_per_block;
 914         blkoff = (inodeno % inodes_per_block) * fs->inodesz;
 915         ext4fs_devread((lbaint_t)itable_blkno * fs->sect_perblk, 0, fs->blksz,
 916                        temp_ptr);
 917         if (ext4fs_log_journal(temp_ptr, itable_blkno))
 918                 goto fail;
 919
 920         memcpy(temp_ptr + blkoff, inode_buffer, fs->inodesz);
 921         if (ext4fs_put_metadata(temp_ptr, itable_blkno))
 922                 goto fail;
 923         /* copy the file content into data blocks */
 924         if (ext4fs_write_file(file_inode, 0, sizebytes, (char *)buffer) == -1) {
 925                 printf("Error in copying content\n");
 926                 goto fail;
 927         }
 928         ibmap_idx = parent_inodeno / ext4fs_root->sblock.inodes_per_group;
 929         parent_inodeno--;
 930         parent_itable_blkno = __le32_to_cpu(fs->bgd[ibmap_idx].inode_table_id) +
 931             (parent_inodeno %
 932              __le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
 933         blkoff = (parent_inodeno % inodes_per_block) * fs->inodesz;
 934         if (parent_itable_blkno != itable_blkno) {
 935                 memset(temp_ptr, '\0', fs->blksz);
 936                 ext4fs_devread((lbaint_t)parent_itable_blkno * fs->sect_perblk,
 937                                0, fs->blksz, temp_ptr);
 938                 if (ext4fs_log_journal(temp_ptr, parent_itable_blkno))
 939                         goto fail;
 940
 941                 memcpy(temp_ptr + blkoff, g_parent_inode,
 942                         sizeof(struct ext2_inode));
 943                 if (ext4fs_put_metadata(temp_ptr, parent_itable_blkno))
 944                         goto fail;
 945                 free(temp_ptr);
 946         } else {
 947                 /*
 948                  * If parent and child fall in same inode table block
 949                  * both should be kept in 1 buffer
 950                  */
 951                 memcpy(temp_ptr + blkoff, g_parent_inode,
 952                        sizeof(struct ext2_inode));
 953                 gd_index--;
 954                 if (ext4fs_put_metadata(temp_ptr, itable_blkno))
 955                         goto fail;
 956                 free(temp_ptr);
 957         }
 958         ext4fs_update();
 959         ext4fs_deinit();
 960
 961         fs->first_pass_bbmap = 0;
 962         fs->curr_blkno = 0;
 963         fs->first_pass_ibmap = 0;
 964         fs->curr_inode_no = 0;
 965         free(inode_buffer);
 966         free(g_parent_inode);
 967         g_parent_inode = NULL;
 968
 969         return 0;
 970 fail:
 971         ext4fs_deinit();
 972         free(inode_buffer);
 973         free(g_parent_inode);
 974         g_parent_inode = NULL;
 975
 976         return -1;
 977 }