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