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 <div64.h>
  44 #include "ext4_common.h"
  45
  46 int ext4fs_symlinknest;
  47 struct ext_filesystem ext_fs;
  48
  49 struct ext_filesystem *get_fs(void)
  50 {
  51         return &ext_fs;
  52 }
  53
  54 void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
  55 {
  56         if ((node != &ext4fs_root->diropen) && (node != currroot))
  57                 free(node);
  58 }
  59
  60 /*
  61  * Taken from openmoko-kernel mailing list: By Andy green
  62  * Optimized read file API : collects and defers contiguous sector
  63  * reads into one potentially more efficient larger sequential read action
  64  */
  65 int ext4fs_read_file(struct ext2fs_node *node, int pos,
  66                 unsigned int len, char *buf)
  67 {
  68         int i;
  69         int blockcnt;
  70         int log2blocksize = LOG2_EXT2_BLOCK_SIZE(node->data);
  71         int blocksize = 1 << (log2blocksize + DISK_SECTOR_BITS);
  72         unsigned int filesize = __le32_to_cpu(node->inode.size);
  73         int previous_block_number = -1;
  74         int delayed_start = 0;
  75         int delayed_extent = 0;
  76         int delayed_skipfirst = 0;
  77         int delayed_next = 0;
  78         char *delayed_buf = NULL;
  79         short status;
  80
  81         /* Adjust len so it we can't read past the end of the file. */
  82         if (len > filesize)
  83                 len = filesize;
  84
  85         blockcnt = ((len + pos) + blocksize - 1) / blocksize;
  86
  87         for (i = pos / blocksize; i < blockcnt; i++) {
  88                 int blknr;
  89                 int blockoff = pos % blocksize;
  90                 int blockend = blocksize;
  91                 int skipfirst = 0;
  92                 blknr = read_allocated_block(&(node->inode), i);
  93                 if (blknr < 0)
  94                         return -1;
  95
  96                 blknr = blknr << log2blocksize;
  97
  98                 /* Last block.  */
  99                 if (i == blockcnt - 1) {
 100                         blockend = (len + pos) % blocksize;
 101
 102                         /* The last portion is exactly blocksize. */
 103                         if (!blockend)
 104                                 blockend = blocksize;
 105                 }
 106
 107                 /* First block. */
 108                 if (i == pos / blocksize) {
 109                         skipfirst = blockoff;
 110                         blockend -= skipfirst;
 111                 }
 112                 if (blknr) {
 113                         int status;
 114
 115                         if (previous_block_number != -1) {
 116                                 if (delayed_next == blknr) {
 117                                         delayed_extent += blockend;
 118                                         delayed_next += blockend >> SECTOR_BITS;
 119                                 } else {        /* spill */
 120                                         status = ext4fs_devread(delayed_start,
 121                                                         delayed_skipfirst,
 122                                                         delayed_extent,
 123                                                         delayed_buf);
 124                                         if (status == 0)
 125                                                 return -1;
 126                                         previous_block_number = blknr;
 127                                         delayed_start = blknr;
 128                                         delayed_extent = blockend;
 129                                         delayed_skipfirst = skipfirst;
 130                                         delayed_buf = buf;
 131                                         delayed_next = blknr +
 132                                                 (blockend >> SECTOR_BITS);
 133                                 }
 134                         } else {
 135                                 previous_block_number = blknr;
 136                                 delayed_start = blknr;
 137                                 delayed_extent = blockend;
 138                                 delayed_skipfirst = skipfirst;
 139                                 delayed_buf = buf;
 140                                 delayed_next = blknr +
 141                                         (blockend >> SECTOR_BITS);
 142                         }
 143                 } else {
 144                         if (previous_block_number != -1) {
 145                                 /* spill */
 146                                 status = ext4fs_devread(delayed_start,
 147                                                         delayed_skipfirst,
 148                                                         delayed_extent,
 149                                                         delayed_buf);
 150                                 if (status == 0)
 151                                         return -1;
 152                                 previous_block_number = -1;
 153                         }
 154                         memset(buf, 0, blocksize - skipfirst);
 155                 }
 156                 buf += blocksize - skipfirst;
 157         }
 158         if (previous_block_number != -1) {
 159                 /* spill */
 160                 status = ext4fs_devread(delayed_start,
 161                                         delayed_skipfirst, delayed_extent,
 162                                         delayed_buf);
 163                 if (status == 0)
 164                         return -1;
 165                 previous_block_number = -1;
 166         }
 167
 168         return len;
 169 }
 170
 171 int ext4fs_ls(const char *dirname)
 172 {
 173         struct ext2fs_node *dirnode;
 174         int status;
 175
 176         if (dirname == NULL)
 177                 return 0;
 178
 179         status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
 180                                   FILETYPE_DIRECTORY);
 181         if (status != 1) {
 182                 printf("** Can not find directory. **\n");
 183                 return 1;
 184         }
 185
 186         ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
 187         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 188
 189         return 0;
 190 }
 191
 192 int ext4fs_read(char *buf, unsigned len)
 193 {
 194         if (ext4fs_root == NULL || ext4fs_file == NULL)
 195                 return 0;
 196
 197         return ext4fs_read_file(ext4fs_file, 0, len, buf);
 198 }
 199
 200 #if defined(CONFIG_EXT4_WRITE)
 201 static void ext4fs_update(void)
 202 {
 203         short i;
 204         ext4fs_update_journal();
 205         struct ext_filesystem *fs = get_fs();
 206
 207         /* update  super block */
 208         put_ext4((uint64_t)(SUPERBLOCK_SIZE),
 209                  (struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
 210
 211         /* update block groups */
 212         for (i = 0; i < fs->no_blkgrp; i++) {
 213                 fs->bgd[i].bg_checksum = ext4fs_checksum_update(i);
 214                 put_ext4((uint64_t)(fs->bgd[i].block_id * fs->blksz),
 215                          fs->blk_bmaps[i], fs->blksz);
 216         }
 217
 218         /* update inode table groups */
 219         for (i = 0; i < fs->no_blkgrp; i++) {
 220                 put_ext4((uint64_t) (fs->bgd[i].inode_id * fs->blksz),
 221                          fs->inode_bmaps[i], fs->blksz);
 222         }
 223
 224         /* update the block group descriptor table */
 225         put_ext4((uint64_t)(fs->gdtable_blkno * fs->blksz),
 226                  (struct ext2_block_group *)fs->gdtable,
 227                  (fs->blksz * fs->no_blk_pergdt));
 228
 229         ext4fs_dump_metadata();
 230
 231         gindex = 0;
 232         gd_index = 0;
 233 }
 234
 235 int ext4fs_get_bgdtable(void)
 236 {
 237         int status;
 238         int grp_desc_size;
 239         struct ext_filesystem *fs = get_fs();
 240         grp_desc_size = sizeof(struct ext2_block_group);
 241         fs->no_blk_pergdt = (fs->no_blkgrp * grp_desc_size) / fs->blksz;
 242         if ((fs->no_blkgrp * grp_desc_size) % fs->blksz)
 243                 fs->no_blk_pergdt++;
 244
 245         /* allocate memory for gdtable */
 246         fs->gdtable = zalloc(fs->blksz * fs->no_blk_pergdt);
 247         if (!fs->gdtable)
 248                 return -ENOMEM;
 249         /* read the group descriptor table */
 250         status = ext4fs_devread(fs->gdtable_blkno * fs->sect_perblk, 0,
 251                                 fs->blksz * fs->no_blk_pergdt, fs->gdtable);
 252         if (status == 0)
 253                 goto fail;
 254
 255         if (ext4fs_log_gdt(fs->gdtable)) {
 256                 printf("Error in ext4fs_log_gdt\n");
 257                 return -1;
 258         }
 259
 260         return 0;
 261 fail:
 262         free(fs->gdtable);
 263         fs->gdtable = NULL;
 264
 265         return -1;
 266 }
 267
 268 static void delete_single_indirect_block(struct ext2_inode *inode)
 269 {
 270         struct ext2_block_group *bgd = NULL;
 271         static int prev_bg_bmap_idx = -1;
 272         long int blknr;
 273         int remainder;
 274         int bg_idx;
 275         int status;
 276         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 277         struct ext_filesystem *fs = get_fs();
 278         char *journal_buffer = zalloc(fs->blksz);
 279         if (!journal_buffer) {
 280                 printf("No memory\n");
 281                 return;
 282         }
 283         /* get  block group descriptor table */
 284         bgd = (struct ext2_block_group *)fs->gdtable;
 285
 286         /* deleting the single indirect block associated with inode */
 287         if (inode->b.blocks.indir_block != 0) {
 288                 debug("SIPB releasing %u\n", inode->b.blocks.indir_block);
 289                 blknr = inode->b.blocks.indir_block;
 290                 if (fs->blksz != 1024) {
 291                         bg_idx = blknr / blk_per_grp;
 292                 } else {
 293                         bg_idx = blknr / blk_per_grp;
 294                         remainder = blknr % blk_per_grp;
 295                         if (!remainder)
 296                                 bg_idx--;
 297                 }
 298                 ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
 299                 bgd[bg_idx].free_blocks++;
 300                 fs->sb->free_blocks++;
 301                 /* journal backup */
 302                 if (prev_bg_bmap_idx != bg_idx) {
 303                         status =
 304                             ext4fs_devread(bgd[bg_idx].block_id *
 305                                            fs->sect_perblk, 0, fs->blksz,
 306                                            journal_buffer);
 307                         if (status == 0)
 308                                 goto fail;
 309                         if (ext4fs_log_journal
 310                             (journal_buffer, bgd[bg_idx].block_id))
 311                                 goto fail;
 312                         prev_bg_bmap_idx = bg_idx;
 313                 }
 314         }
 315 fail:
 316         free(journal_buffer);
 317 }
 318
 319 static void delete_double_indirect_block(struct ext2_inode *inode)
 320 {
 321         int i;
 322         short status;
 323         static int prev_bg_bmap_idx = -1;
 324         long int blknr;
 325         int remainder;
 326         int bg_idx;
 327         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 328         unsigned int *di_buffer = NULL;
 329         unsigned int *DIB_start_addr = NULL;
 330         struct ext2_block_group *bgd = NULL;
 331         struct ext_filesystem *fs = get_fs();
 332         char *journal_buffer = zalloc(fs->blksz);
 333         if (!journal_buffer) {
 334                 printf("No memory\n");
 335                 return;
 336         }
 337         /* get the block group descriptor table */
 338         bgd = (struct ext2_block_group *)fs->gdtable;
 339
 340         if (inode->b.blocks.double_indir_block != 0) {
 341                 di_buffer = zalloc(fs->blksz);
 342                 if (!di_buffer) {
 343                         printf("No memory\n");
 344                         return;
 345                 }
 346                 DIB_start_addr = (unsigned int *)di_buffer;
 347                 blknr = inode->b.blocks.double_indir_block;
 348                 status = ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
 349                                         (char *)di_buffer);
 350                 for (i = 0; i < fs->blksz / sizeof(int); i++) {
 351                         if (*di_buffer == 0)
 352                                 break;
 353
 354                         debug("DICB releasing %u\n", *di_buffer);
 355                         if (fs->blksz != 1024) {
 356                                 bg_idx = (*di_buffer) / blk_per_grp;
 357                         } else {
 358                                 bg_idx = (*di_buffer) / blk_per_grp;
 359                                 remainder = (*di_buffer) % blk_per_grp;
 360                                 if (!remainder)
 361                                         bg_idx--;
 362                         }
 363                         ext4fs_reset_block_bmap(*di_buffer,
 364                                         fs->blk_bmaps[bg_idx], bg_idx);
 365                         di_buffer++;
 366                         bgd[bg_idx].free_blocks++;
 367                         fs->sb->free_blocks++;
 368                         /* journal backup */
 369                         if (prev_bg_bmap_idx != bg_idx) {
 370                                 status = ext4fs_devread(bgd[bg_idx].block_id
 371                                                         * fs->sect_perblk, 0,
 372                                                         fs->blksz,
 373                                                         journal_buffer);
 374                                 if (status == 0)
 375                                         goto fail;
 376
 377                                 if (ext4fs_log_journal(journal_buffer,
 378                                                         bgd[bg_idx].block_id))
 379                                         goto fail;
 380                                 prev_bg_bmap_idx = bg_idx;
 381                         }
 382                 }
 383
 384                 /* removing the parent double indirect block */
 385                 blknr = inode->b.blocks.double_indir_block;
 386                 if (fs->blksz != 1024) {
 387                         bg_idx = blknr / blk_per_grp;
 388                 } else {
 389                         bg_idx = blknr / blk_per_grp;
 390                         remainder = blknr % blk_per_grp;
 391                         if (!remainder)
 392                                 bg_idx--;
 393                 }
 394                 ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
 395                 bgd[bg_idx].free_blocks++;
 396                 fs->sb->free_blocks++;
 397                 /* journal backup */
 398                 if (prev_bg_bmap_idx != bg_idx) {
 399                         memset(journal_buffer, '\0', fs->blksz);
 400                         status = ext4fs_devread(bgd[bg_idx].block_id *
 401                                                 fs->sect_perblk, 0, fs->blksz,
 402                                                 journal_buffer);
 403                         if (status == 0)
 404                                 goto fail;
 405
 406                         if (ext4fs_log_journal(journal_buffer,
 407                                                 bgd[bg_idx].block_id))
 408                                 goto fail;
 409                         prev_bg_bmap_idx = bg_idx;
 410                 }
 411                 debug("DIPB releasing %ld\n", blknr);
 412         }
 413 fail:
 414         free(DIB_start_addr);
 415         free(journal_buffer);
 416 }
 417
 418 static void delete_triple_indirect_block(struct ext2_inode *inode)
 419 {
 420         int i, j;
 421         short status;
 422         static int prev_bg_bmap_idx = -1;
 423         long int blknr;
 424         int remainder;
 425         int bg_idx;
 426         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 427         unsigned int *tigp_buffer = NULL;
 428         unsigned int *tib_start_addr = NULL;
 429         unsigned int *tip_buffer = NULL;
 430         unsigned int *tipb_start_addr = NULL;
 431         struct ext2_block_group *bgd = NULL;
 432         struct ext_filesystem *fs = get_fs();
 433         char *journal_buffer = zalloc(fs->blksz);
 434         if (!journal_buffer) {
 435                 printf("No memory\n");
 436                 return;
 437         }
 438         /* get block group descriptor table */
 439         bgd = (struct ext2_block_group *)fs->gdtable;
 440
 441         if (inode->b.blocks.triple_indir_block != 0) {
 442                 tigp_buffer = zalloc(fs->blksz);
 443                 if (!tigp_buffer) {
 444                         printf("No memory\n");
 445                         return;
 446                 }
 447                 tib_start_addr = (unsigned int *)tigp_buffer;
 448                 blknr = inode->b.blocks.triple_indir_block;
 449                 status = ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
 450                                         (char *)tigp_buffer);
 451                 for (i = 0; i < fs->blksz / sizeof(int); i++) {
 452                         if (*tigp_buffer == 0)
 453                                 break;
 454                         debug("tigp buffer releasing %u\n", *tigp_buffer);
 455
 456                         tip_buffer = zalloc(fs->blksz);
 457                         if (!tip_buffer)
 458                                 goto fail;
 459                         tipb_start_addr = (unsigned int *)tip_buffer;
 460                         status = ext4fs_devread((*tigp_buffer) *
 461                                                 fs->sect_perblk, 0, fs->blksz,
 462                                                 (char *)tip_buffer);
 463                         for (j = 0; j < fs->blksz / sizeof(int); j++) {
 464                                 if (*tip_buffer == 0)
 465                                         break;
 466                                 if (fs->blksz != 1024) {
 467                                         bg_idx = (*tip_buffer) / blk_per_grp;
 468                                 } else {
 469                                         bg_idx = (*tip_buffer) / blk_per_grp;
 470
 471                                         remainder = (*tip_buffer) % blk_per_grp;
 472                                         if (!remainder)
 473                                                 bg_idx--;
 474                                 }
 475
 476                                 ext4fs_reset_block_bmap(*tip_buffer,
 477                                                         fs->blk_bmaps[bg_idx],
 478                                                         bg_idx);
 479
 480                                 tip_buffer++;
 481                                 bgd[bg_idx].free_blocks++;
 482                                 fs->sb->free_blocks++;
 483                                 /* journal backup */
 484                                 if (prev_bg_bmap_idx != bg_idx) {
 485                                         status =
 486                                             ext4fs_devread(
 487                                                         bgd[bg_idx].block_id *
 488                                                         fs->sect_perblk, 0,
 489                                                         fs->blksz,
 490                                                         journal_buffer);
 491                                         if (status == 0)
 492                                                 goto fail;
 493
 494                                         if (ext4fs_log_journal(journal_buffer,
 495                                                                bgd[bg_idx].
 496                                                                block_id))
 497                                                 goto fail;
 498                                         prev_bg_bmap_idx = bg_idx;
 499                                 }
 500                         }
 501                         free(tipb_start_addr);
 502                         tipb_start_addr = NULL;
 503
 504                         /*
 505                          * removing the grand parent blocks
 506                          * which is connected to inode
 507                          */
 508                         if (fs->blksz != 1024) {
 509                                 bg_idx = (*tigp_buffer) / blk_per_grp;
 510                         } else {
 511                                 bg_idx = (*tigp_buffer) / blk_per_grp;
 512
 513                                 remainder = (*tigp_buffer) % blk_per_grp;
 514                                 if (!remainder)
 515                                         bg_idx--;
 516                         }
 517                         ext4fs_reset_block_bmap(*tigp_buffer,
 518                                                 fs->blk_bmaps[bg_idx], bg_idx);
 519
 520                         tigp_buffer++;
 521                         bgd[bg_idx].free_blocks++;
 522                         fs->sb->free_blocks++;
 523                         /* journal backup */
 524                         if (prev_bg_bmap_idx != bg_idx) {
 525                                 memset(journal_buffer, '\0', fs->blksz);
 526                                 status =
 527                                     ext4fs_devread(bgd[bg_idx].block_id *
 528                                                    fs->sect_perblk, 0,
 529                                                    fs->blksz, journal_buffer);
 530                                 if (status == 0)
 531                                         goto fail;
 532
 533                                 if (ext4fs_log_journal(journal_buffer,
 534                                                         bgd[bg_idx].block_id))
 535                                         goto fail;
 536                                 prev_bg_bmap_idx = bg_idx;
 537                         }
 538                 }
 539
 540                 /* removing the grand parent triple indirect block */
 541                 blknr = inode->b.blocks.triple_indir_block;
 542                 if (fs->blksz != 1024) {
 543                         bg_idx = blknr / blk_per_grp;
 544                 } else {
 545                         bg_idx = blknr / blk_per_grp;
 546                         remainder = blknr % blk_per_grp;
 547                         if (!remainder)
 548                                 bg_idx--;
 549                 }
 550                 ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
 551                 bgd[bg_idx].free_blocks++;
 552                 fs->sb->free_blocks++;
 553                 /* journal backup */
 554                 if (prev_bg_bmap_idx != bg_idx) {
 555                         memset(journal_buffer, '\0', fs->blksz);
 556                         status = ext4fs_devread(bgd[bg_idx].block_id *
 557                                                 fs->sect_perblk, 0, fs->blksz,
 558                                                 journal_buffer);
 559                         if (status == 0)
 560                                 goto fail;
 561
 562                         if (ext4fs_log_journal(journal_buffer,
 563                                                 bgd[bg_idx].block_id))
 564                                 goto fail;
 565                         prev_bg_bmap_idx = bg_idx;
 566                 }
 567                 debug("tigp buffer itself releasing %ld\n", blknr);
 568         }
 569 fail:
 570         free(tib_start_addr);
 571         free(tipb_start_addr);
 572         free(journal_buffer);
 573 }
 574
 575 static int ext4fs_delete_file(int inodeno)
 576 {
 577         struct ext2_inode inode;
 578         short status;
 579         int i;
 580         int remainder;
 581         long int blknr;
 582         int bg_idx;
 583         int ibmap_idx;
 584         char *read_buffer = NULL;
 585         char *start_block_address = NULL;
 586         unsigned int no_blocks;
 587
 588         static int prev_bg_bmap_idx = -1;
 589         unsigned int inodes_per_block;
 590         long int blkno;
 591         unsigned int blkoff;
 592         unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
 593         unsigned int inode_per_grp = ext4fs_root->sblock.inodes_per_group;
 594         struct ext2_inode *inode_buffer = NULL;
 595         struct ext2_block_group *bgd = NULL;
 596         struct ext_filesystem *fs = get_fs();
 597         char *journal_buffer = zalloc(fs->blksz);
 598         if (!journal_buffer)
 599                 return -ENOMEM;
 600         /* get the block group descriptor table */
 601         bgd = (struct ext2_block_group *)fs->gdtable;
 602         status = ext4fs_read_inode(ext4fs_root, inodeno, &inode);
 603         if (status == 0)
 604                 goto fail;
 605
 606         /* read the block no allocated to a file */
 607         no_blocks = inode.size / fs->blksz;
 608         if (inode.size % fs->blksz)
 609                 no_blocks++;
 610
 611         if (le32_to_cpu(inode.flags) & EXT4_EXTENTS_FL) {
 612                 struct ext2fs_node *node_inode =
 613                     zalloc(sizeof(struct ext2fs_node));
 614                 if (!node_inode)
 615                         goto fail;
 616                 node_inode->data = ext4fs_root;
 617                 node_inode->ino = inodeno;
 618                 node_inode->inode_read = 0;
 619                 memcpy(&(node_inode->inode), &inode, sizeof(struct ext2_inode));
 620
 621                 for (i = 0; i < no_blocks; i++) {
 622                         blknr = read_allocated_block(&(node_inode->inode), i);
 623                         if (fs->blksz != 1024) {
 624                                 bg_idx = blknr / blk_per_grp;
 625                         } else {
 626                                 bg_idx = blknr / blk_per_grp;
 627                                 remainder = blknr % blk_per_grp;
 628                                 if (!remainder)
 629                                         bg_idx--;
 630                         }
 631                         ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx],
 632                                                 bg_idx);
 633                         debug("EXT4_EXTENTS Block releasing %ld: %d\n",
 634                               blknr, bg_idx);
 635
 636                         bgd[bg_idx].free_blocks++;
 637                         fs->sb->free_blocks++;
 638
 639                         /* journal backup */
 640                         if (prev_bg_bmap_idx != bg_idx) {
 641                                 status =
 642                                     ext4fs_devread(bgd[bg_idx].block_id *
 643                                                    fs->sect_perblk, 0,
 644                                                    fs->blksz, journal_buffer);
 645                                 if (status == 0)
 646                                         goto fail;
 647                                 if (ext4fs_log_journal(journal_buffer,
 648                                                         bgd[bg_idx].block_id))
 649                                         goto fail;
 650                                 prev_bg_bmap_idx = bg_idx;
 651                         }
 652                 }
 653                 if (node_inode) {
 654                         free(node_inode);
 655                         node_inode = NULL;
 656                 }
 657         } else {
 658
 659                 delete_single_indirect_block(&inode);
 660                 delete_double_indirect_block(&inode);
 661                 delete_triple_indirect_block(&inode);
 662
 663                 /* read the block no allocated to a file */
 664                 no_blocks = inode.size / fs->blksz;
 665                 if (inode.size % fs->blksz)
 666                         no_blocks++;
 667                 for (i = 0; i < no_blocks; i++) {
 668                         blknr = read_allocated_block(&inode, i);
 669                         if (fs->blksz != 1024) {
 670                                 bg_idx = blknr / blk_per_grp;
 671                         } else {
 672                                 bg_idx = blknr / blk_per_grp;
 673                                 remainder = blknr % blk_per_grp;
 674                                 if (!remainder)
 675                                         bg_idx--;
 676                         }
 677                         ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx],
 678                                                 bg_idx);
 679                         debug("ActualB releasing %ld: %d\n", blknr, bg_idx);
 680
 681                         bgd[bg_idx].free_blocks++;
 682                         fs->sb->free_blocks++;
 683                         /* journal backup */
 684                         if (prev_bg_bmap_idx != bg_idx) {
 685                                 memset(journal_buffer, '\0', fs->blksz);
 686                                 status = ext4fs_devread(bgd[bg_idx].block_id
 687                                                         * fs->sect_perblk,
 688                                                         0, fs->blksz,
 689                                                         journal_buffer);
 690                                 if (status == 0)
 691                                         goto fail;
 692                                 if (ext4fs_log_journal(journal_buffer,
 693                                                 bgd[bg_idx].block_id))
 694                                         goto fail;
 695                                 prev_bg_bmap_idx = bg_idx;
 696                         }
 697                 }
 698         }
 699
 700         /* from the inode no to blockno */
 701         inodes_per_block = fs->blksz / fs->inodesz;
 702         ibmap_idx = inodeno / inode_per_grp;
 703
 704         /* get the block no */
 705         inodeno--;
 706         blkno = __le32_to_cpu(bgd[ibmap_idx].inode_table_id) +
 707                 (inodeno % __le32_to_cpu(inode_per_grp)) / inodes_per_block;
 708
 709         /* get the offset of the inode */
 710         blkoff = ((inodeno) % inodes_per_block) * fs->inodesz;
 711
 712         /* read the block no containing the inode */
 713         read_buffer = zalloc(fs->blksz);
 714         if (!read_buffer)
 715                 goto fail;
 716         start_block_address = read_buffer;
 717         status = ext4fs_devread(blkno * fs->sect_perblk,
 718                                 0, fs->blksz, read_buffer);
 719         if (status == 0)
 720                 goto fail;
 721
 722         if (ext4fs_log_journal(read_buffer, blkno))
 723                 goto fail;
 724
 725         read_buffer = read_buffer + blkoff;
 726         inode_buffer = (struct ext2_inode *)read_buffer;
 727         memset(inode_buffer, '\0', sizeof(struct ext2_inode));
 728
 729         /* write the inode to original position in inode table */
 730         if (ext4fs_put_metadata(start_block_address, blkno))
 731                 goto fail;
 732
 733         /* update the respective inode bitmaps */
 734         inodeno++;
 735         ext4fs_reset_inode_bmap(inodeno, fs->inode_bmaps[ibmap_idx], ibmap_idx);
 736         bgd[ibmap_idx].free_inodes++;
 737         fs->sb->free_inodes++;
 738         /* journal backup */
 739         memset(journal_buffer, '\0', fs->blksz);
 740         status = ext4fs_devread(bgd[ibmap_idx].inode_id *
 741                                 fs->sect_perblk, 0, fs->blksz, journal_buffer);
 742         if (status == 0)
 743                 goto fail;
 744         if (ext4fs_log_journal(journal_buffer, bgd[ibmap_idx].inode_id))
 745                 goto fail;
 746
 747         ext4fs_update();
 748         ext4fs_deinit();
 749
 750         if (ext4fs_init() != 0) {
 751                 printf("error in File System init\n");
 752                 goto fail;
 753         }
 754
 755         free(start_block_address);
 756         free(journal_buffer);
 757
 758         return 0;
 759 fail:
 760         free(start_block_address);
 761         free(journal_buffer);
 762
 763         return -1;
 764 }
 765
 766 int ext4fs_init(void)
 767 {
 768         short status;
 769         int i;
 770         unsigned int real_free_blocks = 0;
 771         struct ext_filesystem *fs = get_fs();
 772
 773         /* populate fs */
 774         fs->blksz = EXT2_BLOCK_SIZE(ext4fs_root);
 775         fs->inodesz = INODE_SIZE_FILESYSTEM(ext4fs_root);
 776         fs->sect_perblk = fs->blksz / SECTOR_SIZE;
 777
 778         /* get the superblock */
 779         fs->sb = zalloc(SUPERBLOCK_SIZE);
 780         if (!fs->sb)
 781                 return -ENOMEM;
 782         if (!ext4fs_devread(SUPERBLOCK_SECTOR, 0, SUPERBLOCK_SIZE,
 783                         (char *)fs->sb))
 784                 goto fail;
 785
 786         /* init journal */
 787         if (ext4fs_init_journal())
 788                 goto fail;
 789
 790         /* get total no of blockgroups */
 791         fs->no_blkgrp = (uint32_t)ext4fs_div_roundup(
 792                         (ext4fs_root->sblock.total_blocks -
 793                         ext4fs_root->sblock.first_data_block),
 794                         ext4fs_root->sblock.blocks_per_group);
 795
 796         /* get the block group descriptor table */
 797         fs->gdtable_blkno = ((EXT2_MIN_BLOCK_SIZE == fs->blksz) + 1);
 798         if (ext4fs_get_bgdtable() == -1) {
 799                 printf("Error in getting the block group descriptor table\n");
 800                 goto fail;
 801         }
 802         fs->bgd = (struct ext2_block_group *)fs->gdtable;
 803
 804         /* load all the available bitmap block of the partition */
 805         fs->blk_bmaps = zalloc(fs->no_blkgrp * sizeof(char *));
 806         if (!fs->blk_bmaps)
 807                 goto fail;
 808         for (i = 0; i < fs->no_blkgrp; i++) {
 809                 fs->blk_bmaps[i] = zalloc(fs->blksz);
 810                 if (!fs->blk_bmaps[i])
 811                         goto fail;
 812         }
 813
 814         for (i = 0; i < fs->no_blkgrp; i++) {
 815                 status =
 816                     ext4fs_devread(fs->bgd[i].block_id * fs->sect_perblk, 0,
 817                                    fs->blksz, (char *)fs->blk_bmaps[i]);
 818                 if (status == 0)
 819                         goto fail;
 820         }
 821
 822         /* load all the available inode bitmap of the partition */
 823         fs->inode_bmaps = zalloc(fs->no_blkgrp * sizeof(unsigned char *));
 824         if (!fs->inode_bmaps)
 825                 goto fail;
 826         for (i = 0; i < fs->no_blkgrp; i++) {
 827                 fs->inode_bmaps[i] = zalloc(fs->blksz);
 828                 if (!fs->inode_bmaps[i])
 829                         goto fail;
 830         }
 831
 832         for (i = 0; i < fs->no_blkgrp; i++) {
 833                 status = ext4fs_devread(fs->bgd[i].inode_id * fs->sect_perblk,
 834                                         0, fs->blksz,
 835                                         (char *)fs->inode_bmaps[i]);
 836                 if (status == 0)
 837                         goto fail;
 838         }
 839
 840         /*
 841          * check filesystem consistency with free blocks of file system
 842          * some time we observed that superblock freeblocks does not match
 843          * with the  blockgroups freeblocks when improper
 844          * reboot of a linux kernel
 845          */
 846         for (i = 0; i < fs->no_blkgrp; i++)
 847                 real_free_blocks = real_free_blocks + fs->bgd[i].free_blocks;
 848         if (real_free_blocks != fs->sb->free_blocks)
 849                 fs->sb->free_blocks = real_free_blocks;
 850
 851         return 0;
 852 fail:
 853         ext4fs_deinit();
 854
 855         return -1;
 856 }
 857
 858 void ext4fs_deinit(void)
 859 {
 860         int i;
 861         struct ext2_inode inode_journal;
 862         struct journal_superblock_t *jsb;
 863         long int blknr;
 864         struct ext_filesystem *fs = get_fs();
 865
 866         /* free journal */
 867         char *temp_buff = zalloc(fs->blksz);
 868         if (temp_buff) {
 869                 ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO,
 870                                   &inode_journal);
 871                 blknr = read_allocated_block(&inode_journal,
 872                                         EXT2_JOURNAL_SUPERBLOCK);
 873                 ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
 874                                temp_buff);
 875                 jsb = (struct journal_superblock_t *)temp_buff;
 876                 jsb->s_start = cpu_to_be32(0);
 877                 put_ext4((uint64_t) (blknr * fs->blksz),
 878                          (struct journal_superblock_t *)temp_buff, fs->blksz);
 879                 free(temp_buff);
 880         }
 881         ext4fs_free_journal();
 882
 883         /* get the superblock */
 884         ext4fs_devread(SUPERBLOCK_SECTOR, 0, SUPERBLOCK_SIZE, (char *)fs->sb);
 885         fs->sb->feature_incompat &= ~EXT3_FEATURE_INCOMPAT_RECOVER;
 886         put_ext4((uint64_t)(SUPERBLOCK_SIZE),
 887                  (struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
 888         free(fs->sb);
 889         fs->sb = NULL;
 890
 891         if (fs->blk_bmaps) {
 892                 for (i = 0; i < fs->no_blkgrp; i++) {
 893                         free(fs->blk_bmaps[i]);
 894                         fs->blk_bmaps[i] = NULL;
 895                 }
 896                 free(fs->blk_bmaps);
 897                 fs->blk_bmaps = NULL;
 898         }
 899
 900         if (fs->inode_bmaps) {
 901                 for (i = 0; i < fs->no_blkgrp; i++) {
 902                         free(fs->inode_bmaps[i]);
 903                         fs->inode_bmaps[i] = NULL;
 904                 }
 905                 free(fs->inode_bmaps);
 906                 fs->inode_bmaps = NULL;
 907         }
 908
 909
 910         free(fs->gdtable);
 911         fs->gdtable = NULL;
 912         fs->bgd = NULL;
 913         /*
 914          * reinitiliazed the global inode and
 915          * block bitmap first execution check variables
 916          */
 917         fs->first_pass_ibmap = 0;
 918         fs->first_pass_bbmap = 0;
 919         fs->curr_inode_no = 0;
 920         fs->curr_blkno = 0;
 921 }
 922
 923 static int ext4fs_write_file(struct ext2_inode *file_inode,
 924                              int pos, unsigned int len, char *buf)
 925 {
 926         int i;
 927         int blockcnt;
 928         int log2blocksize = LOG2_EXT2_BLOCK_SIZE(ext4fs_root);
 929         unsigned int filesize = __le32_to_cpu(file_inode->size);
 930         struct ext_filesystem *fs = get_fs();
 931         int previous_block_number = -1;
 932         int delayed_start = 0;
 933         int delayed_extent = 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_buf = buf;
 967                                         delayed_next = blknr +
 968                                             (blockend >> SECTOR_BITS);
 969                                 }
 970                         } else {
 971                                 previous_block_number = blknr;
 972                                 delayed_start = blknr;
 973                                 delayed_extent = blockend;
 974                                 delayed_buf = buf;
 975                                 delayed_next = blknr +
 976                                     (blockend >> SECTOR_BITS);
 977                         }
 978                 } else {
 979                         if (previous_block_number != -1) {
 980                                 /* spill */
 981                                 put_ext4((uint64_t) (delayed_start *
 982                                                      SECTOR_SIZE), delayed_buf,
 983                                          (uint32_t) delayed_extent);
 984                                 previous_block_number = -1;
 985                         }
 986                         memset(buf, 0, fs->blksz - skipfirst);
 987                 }
 988                 buf += fs->blksz - skipfirst;
 989         }
 990         if (previous_block_number != -1) {
 991                 /* spill */
 992                 put_ext4((uint64_t) (delayed_start * SECTOR_SIZE),
 993                          delayed_buf, (uint32_t) delayed_extent);
 994                 previous_block_number = -1;
 995         }
 996
 997         return len;
 998 }
 999
1000 int ext4fs_write(const char *fname, unsigned char *buffer,
1001                                         unsigned long sizebytes)
1002 {
1003         int ret = 0;
1004         struct ext2_inode *file_inode = NULL;
1005         unsigned char *inode_buffer = NULL;
1006         int parent_inodeno;
1007         int inodeno;
1008         time_t timestamp = 0;
1009
1010         uint64_t bytes_reqd_for_file;
1011         unsigned int blks_reqd_for_file;
1012         unsigned int blocks_remaining;
1013         int existing_file_inodeno;
1014         char *temp_ptr = NULL;
1015         long int itable_blkno;
1016         long int parent_itable_blkno;
1017         long int blkoff;
1018         struct ext2_sblock *sblock = &(ext4fs_root->sblock);
1019         unsigned int inodes_per_block;
1020         unsigned int ibmap_idx;
1021         struct ext_filesystem *fs = get_fs();
1022         ALLOC_CACHE_ALIGN_BUFFER(char, filename, 256);
1023         memset(filename, 0x00, sizeof(filename));
1024
1025         g_parent_inode = zalloc(sizeof(struct ext2_inode));
1026         if (!g_parent_inode)
1027                 goto fail;
1028
1029         if (ext4fs_init() != 0) {
1030                 printf("error in File System init\n");
1031                 return -1;
1032         }
1033         inodes_per_block = fs->blksz / fs->inodesz;
1034         parent_inodeno = ext4fs_get_parent_inode_num(fname, filename, F_FILE);
1035         if (parent_inodeno == -1)
1036                 goto fail;
1037         if (ext4fs_iget(parent_inodeno, g_parent_inode))
1038                 goto fail;
1039         /* check if the filename is already present in root */
1040         existing_file_inodeno = ext4fs_filename_check(filename);
1041         if (existing_file_inodeno != -1) {
1042                 ret = ext4fs_delete_file(existing_file_inodeno);
1043                 fs->first_pass_bbmap = 0;
1044                 fs->curr_blkno = 0;
1045
1046                 fs->first_pass_ibmap = 0;
1047                 fs->curr_inode_no = 0;
1048                 if (ret)
1049                         goto fail;
1050         }
1051         /* calucalate how many blocks required */
1052         bytes_reqd_for_file = sizebytes;
1053         blks_reqd_for_file = lldiv(bytes_reqd_for_file, fs->blksz);
1054         if (do_div(bytes_reqd_for_file, fs->blksz) != 0) {
1055                 blks_reqd_for_file++;
1056                 debug("total bytes for a file %u\n", blks_reqd_for_file);
1057         }
1058         blocks_remaining = blks_reqd_for_file;
1059         /* test for available space in partition */
1060         if (fs->sb->free_blocks < blks_reqd_for_file) {
1061                 printf("Not enough space on partition !!!\n");
1062                 goto fail;
1063         }
1064
1065         ext4fs_update_parent_dentry(filename, &inodeno, FILETYPE_REG);
1066         /* prepare file inode */
1067         inode_buffer = zalloc(fs->inodesz);
1068         if (!inode_buffer)
1069                 goto fail;
1070         file_inode = (struct ext2_inode *)inode_buffer;
1071         file_inode->mode = S_IFREG | S_IRWXU |
1072             S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH;
1073         /* ToDo: Update correct time */
1074         file_inode->mtime = timestamp;
1075         file_inode->atime = timestamp;
1076         file_inode->ctime = timestamp;
1077         file_inode->nlinks = 1;
1078         file_inode->size = sizebytes;
1079
1080         /* Allocate data blocks */
1081         ext4fs_allocate_blocks(file_inode, blocks_remaining,
1082                                &blks_reqd_for_file);
1083         file_inode->blockcnt = (blks_reqd_for_file * fs->blksz) / SECTOR_SIZE;
1084
1085         temp_ptr = zalloc(fs->blksz);
1086         if (!temp_ptr)
1087                 goto fail;
1088         ibmap_idx = inodeno / ext4fs_root->sblock.inodes_per_group;
1089         inodeno--;
1090         itable_blkno = __le32_to_cpu(fs->bgd[ibmap_idx].inode_table_id) +
1091                         (inodeno % __le32_to_cpu(sblock->inodes_per_group)) /
1092                         inodes_per_block;
1093         blkoff = (inodeno % inodes_per_block) * fs->inodesz;
1094         ext4fs_devread(itable_blkno * fs->sect_perblk, 0, fs->blksz, temp_ptr);
1095         if (ext4fs_log_journal(temp_ptr, itable_blkno))
1096                 goto fail;
1097
1098         memcpy(temp_ptr + blkoff, inode_buffer, fs->inodesz);
1099         if (ext4fs_put_metadata(temp_ptr, itable_blkno))
1100                 goto fail;
1101         /* copy the file content into data blocks */
1102         if (ext4fs_write_file(file_inode, 0, sizebytes, (char *)buffer) == -1) {
1103                 printf("Error in copying content\n");
1104                 goto fail;
1105         }
1106         ibmap_idx = parent_inodeno / ext4fs_root->sblock.inodes_per_group;
1107         parent_inodeno--;
1108         parent_itable_blkno = __le32_to_cpu(fs->bgd[ibmap_idx].inode_table_id) +
1109             (parent_inodeno %
1110              __le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
1111         blkoff = (parent_inodeno % inodes_per_block) * fs->inodesz;
1112         if (parent_itable_blkno != itable_blkno) {
1113                 memset(temp_ptr, '\0', fs->blksz);
1114                 ext4fs_devread(parent_itable_blkno * fs->sect_perblk,
1115                                0, fs->blksz, temp_ptr);
1116                 if (ext4fs_log_journal(temp_ptr, parent_itable_blkno))
1117                         goto fail;
1118
1119                 memcpy(temp_ptr + blkoff, g_parent_inode,
1120                         sizeof(struct ext2_inode));
1121                 if (ext4fs_put_metadata(temp_ptr, parent_itable_blkno))
1122                         goto fail;
1123                 free(temp_ptr);
1124         } else {
1125                 /*
1126                  * If parent and child fall in same inode table block
1127                  * both should be kept in 1 buffer
1128                  */
1129                 memcpy(temp_ptr + blkoff, g_parent_inode,
1130                        sizeof(struct ext2_inode));
1131                 gd_index--;
1132                 if (ext4fs_put_metadata(temp_ptr, itable_blkno))
1133                         goto fail;
1134                 free(temp_ptr);
1135         }
1136         ext4fs_update();
1137         ext4fs_deinit();
1138
1139         fs->first_pass_bbmap = 0;
1140         fs->curr_blkno = 0;
1141         fs->first_pass_ibmap = 0;
1142         fs->curr_inode_no = 0;
1143         free(inode_buffer);
1144         free(g_parent_inode);
1145         g_parent_inode = NULL;
1146
1147         return 0;
1148 fail:
1149         ext4fs_deinit();
1150         free(inode_buffer);
1151         free(g_parent_inode);
1152         g_parent_inode = NULL;
1153
1154         return -1;
1155 }
1156 #endif