fs/ext2/super.c

   1 /*
   2  *  linux/fs/ext2/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/config.h>
  20 #include <linux/module.h>
  21 #include <linux/string.h>
  22 #include <linux/slab.h>
  23 #include <linux/init.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/parser.h>
  26 #include <linux/random.h>
  27 #include <linux/buffer_head.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/vfs.h>
  30 #include <asm/uaccess.h>
  31 #include "ext2.h"
  32 #include "xattr.h"
  33 #include "acl.h"
  34
  35 static void ext2_sync_super(struct super_block *sb,
  36                             struct ext2_super_block *es);
  37 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  38 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf);
  39
  40 void ext2_error (struct super_block * sb, const char * function,
  41                  const char * fmt, ...)
  42 {
  43         va_list args;
  44         struct ext2_sb_info *sbi = EXT2_SB(sb);
  45         struct ext2_super_block *es = sbi->s_es;
  46
  47         if (!(sb->s_flags & MS_RDONLY)) {
  48                 sbi->s_mount_state |= EXT2_ERROR_FS;
  49                 es->s_state =
  50                         cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
  51                 ext2_sync_super(sb, es);
  52         }
  53
  54         va_start(args, fmt);
  55         printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
  56         vprintk(fmt, args);
  57         printk("\n");
  58         va_end(args);
  59
  60         if (test_opt(sb, ERRORS_PANIC))
  61                 panic("EXT2-fs panic from previous error\n");
  62         if (test_opt(sb, ERRORS_RO)) {
  63                 printk("Remounting filesystem read-only\n");
  64                 sb->s_flags |= MS_RDONLY;
  65         }
  66 }
  67
  68 void ext2_warning (struct super_block * sb, const char * function,
  69                    const char * fmt, ...)
  70 {
  71         va_list args;
  72
  73         va_start(args, fmt);
  74         printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
  75                sb->s_id, function);
  76         vprintk(fmt, args);
  77         printk("\n");
  78         va_end(args);
  79 }
  80
  81 void ext2_update_dynamic_rev(struct super_block *sb)
  82 {
  83         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
  84
  85         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
  86                 return;
  87
  88         ext2_warning(sb, __FUNCTION__,
  89                      "updating to rev %d because of new feature flag, "
  90                      "running e2fsck is recommended",
  91                      EXT2_DYNAMIC_REV);
  92
  93         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
  94         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
  95         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
  96         /* leave es->s_feature_*compat flags alone */
  97         /* es->s_uuid will be set by e2fsck if empty */
  98
  99         /*
 100          * The rest of the superblock fields should be zero, and if not it
 101          * means they are likely already in use, so leave them alone.  We
 102          * can leave it up to e2fsck to clean up any inconsistencies there.
 103          */
 104 }
 105
 106 static void ext2_put_super (struct super_block * sb)
 107 {
 108         int db_count;
 109         int i;
 110         struct ext2_sb_info *sbi = EXT2_SB(sb);
 111
 112         ext2_xattr_put_super(sb);
 113         if (!(sb->s_flags & MS_RDONLY)) {
 114                 struct ext2_super_block *es = sbi->s_es;
 115
 116                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 117                 ext2_sync_super(sb, es);
 118         }
 119         db_count = sbi->s_gdb_count;
 120         for (i = 0; i < db_count; i++)
 121                 if (sbi->s_group_desc[i])
 122                         brelse (sbi->s_group_desc[i]);
 123         kfree(sbi->s_group_desc);
 124         kfree(sbi->s_debts);
 125         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 126         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 127         percpu_counter_destroy(&sbi->s_dirs_counter);
 128         brelse (sbi->s_sbh);
 129         sb->s_fs_info = NULL;
 130         kfree(sbi);
 131
 132         return;
 133 }
 134
 135 static kmem_cache_t * ext2_inode_cachep;
 136
 137 static struct inode *ext2_alloc_inode(struct super_block *sb)
 138 {
 139         struct ext2_inode_info *ei;
 140         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL);
 141         if (!ei)
 142                 return NULL;
 143 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 144         ei->i_acl = EXT2_ACL_NOT_CACHED;
 145         ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 146 #endif
 147         ei->vfs_inode.i_version = 1;
 148         return &ei->vfs_inode;
 149 }
 150
 151 static void ext2_destroy_inode(struct inode *inode)
 152 {
 153         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 154 }
 155
 156 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
 157 {
 158         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 159
 160         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 161             SLAB_CTOR_CONSTRUCTOR) {
 162                 rwlock_init(&ei->i_meta_lock);
 163 #ifdef CONFIG_EXT2_FS_XATTR
 164                 init_rwsem(&ei->xattr_sem);
 165 #endif
 166                 inode_init_once(&ei->vfs_inode);
 167         }
 168 }
 169
 170 static int init_inodecache(void)
 171 {
 172         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 173                                              sizeof(struct ext2_inode_info),
 174                                              0, SLAB_RECLAIM_ACCOUNT,
 175                                              init_once, NULL);
 176         if (ext2_inode_cachep == NULL)
 177                 return -ENOMEM;
 178         return 0;
 179 }
 180
 181 static void destroy_inodecache(void)
 182 {
 183         if (kmem_cache_destroy(ext2_inode_cachep))
 184                 printk(KERN_INFO "ext2_inode_cache: not all structures were freed\n");
 185 }
 186
 187 static void ext2_clear_inode(struct inode *inode)
 188 {
 189 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 190         struct ext2_inode_info *ei = EXT2_I(inode);
 191
 192         if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
 193                 posix_acl_release(ei->i_acl);
 194                 ei->i_acl = EXT2_ACL_NOT_CACHED;
 195         }
 196         if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
 197                 posix_acl_release(ei->i_default_acl);
 198                 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 199         }
 200 #endif
 201         if (!is_bad_inode(inode))
 202                 ext2_discard_prealloc(inode);
 203 }
 204
 205
 206 #ifdef CONFIG_QUOTA
 207 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 208 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 209 #endif
 210
 211 static struct super_operations ext2_sops = {
 212         .alloc_inode    = ext2_alloc_inode,
 213         .destroy_inode  = ext2_destroy_inode,
 214         .read_inode     = ext2_read_inode,
 215         .write_inode    = ext2_write_inode,
 216         .delete_inode   = ext2_delete_inode,
 217         .put_super      = ext2_put_super,
 218         .write_super    = ext2_write_super,
 219         .statfs         = ext2_statfs,
 220         .remount_fs     = ext2_remount,
 221         .clear_inode    = ext2_clear_inode,
 222 #ifdef CONFIG_QUOTA
 223         .quota_read     = ext2_quota_read,
 224         .quota_write    = ext2_quota_write,
 225 #endif
 226 };
 227
 228 /* Yes, most of these are left as NULL!!
 229  * A NULL value implies the default, which works with ext2-like file
 230  * systems, but can be improved upon.
 231  * Currently only get_parent is required.
 232  */
 233 struct dentry *ext2_get_parent(struct dentry *child);
 234 static struct export_operations ext2_export_ops = {
 235         .get_parent = ext2_get_parent,
 236 };
 237
 238 static unsigned long get_sb_block(void **data)
 239 {
 240         unsigned long   sb_block;
 241         char            *options = (char *) *data;
 242
 243         if (!options || strncmp(options, "sb=", 3) != 0)
 244                 return 1;       /* Default location */
 245         options += 3;
 246         sb_block = simple_strtoul(options, &options, 0);
 247         if (*options && *options != ',') {
 248                 printk("EXT2-fs: Invalid sb specification: %s\n",
 249                        (char *) *data);
 250                 return 1;
 251         }
 252         if (*options == ',')
 253                 options++;
 254         *data = (void *) options;
 255         return sb_block;
 256 }
 257
 258 enum {
 259         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 260         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 261         Opt_nouid32, Opt_check, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov, Opt_nobh,
 262         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 263         Opt_ignore, Opt_err,
 264 };
 265
 266 static match_table_t tokens = {
 267         {Opt_bsd_df, "bsddf"},
 268         {Opt_minix_df, "minixdf"},
 269         {Opt_grpid, "grpid"},
 270         {Opt_grpid, "bsdgroups"},
 271         {Opt_nogrpid, "nogrpid"},
 272         {Opt_nogrpid, "sysvgroups"},
 273         {Opt_resgid, "resgid=%u"},
 274         {Opt_resuid, "resuid=%u"},
 275         {Opt_sb, "sb=%u"},
 276         {Opt_err_cont, "errors=continue"},
 277         {Opt_err_panic, "errors=panic"},
 278         {Opt_err_ro, "errors=remount-ro"},
 279         {Opt_nouid32, "nouid32"},
 280         {Opt_nocheck, "check=none"},
 281         {Opt_nocheck, "nocheck"},
 282         {Opt_check, "check"},
 283         {Opt_debug, "debug"},
 284         {Opt_oldalloc, "oldalloc"},
 285         {Opt_orlov, "orlov"},
 286         {Opt_nobh, "nobh"},
 287         {Opt_user_xattr, "user_xattr"},
 288         {Opt_nouser_xattr, "nouser_xattr"},
 289         {Opt_acl, "acl"},
 290         {Opt_noacl, "noacl"},
 291         {Opt_ignore, "grpquota"},
 292         {Opt_ignore, "noquota"},
 293         {Opt_ignore, "quota"},
 294         {Opt_ignore, "usrquota"},
 295         {Opt_err, NULL}
 296 };
 297
 298 static int parse_options (char * options,
 299                           struct ext2_sb_info *sbi)
 300 {
 301         char * p;
 302         substring_t args[MAX_OPT_ARGS];
 303         unsigned long kind = EXT2_MOUNT_ERRORS_CONT;
 304         int option;
 305
 306         if (!options)
 307                 return 1;
 308
 309         while ((p = strsep (&options, ",")) != NULL) {
 310                 int token;
 311                 if (!*p)
 312                         continue;
 313
 314                 token = match_token(p, tokens, args);
 315                 switch (token) {
 316                 case Opt_bsd_df:
 317                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 318                         break;
 319                 case Opt_minix_df:
 320                         set_opt (sbi->s_mount_opt, MINIX_DF);
 321                         break;
 322                 case Opt_grpid:
 323                         set_opt (sbi->s_mount_opt, GRPID);
 324                         break;
 325                 case Opt_nogrpid:
 326                         clear_opt (sbi->s_mount_opt, GRPID);
 327                         break;
 328                 case Opt_resuid:
 329                         if (match_int(&args[0], &option))
 330                                 return 0;
 331                         sbi->s_resuid = option;
 332                         break;
 333                 case Opt_resgid:
 334                         if (match_int(&args[0], &option))
 335                                 return 0;
 336                         sbi->s_resgid = option;
 337                         break;
 338                 case Opt_sb:
 339                         /* handled by get_sb_block() instead of here */
 340                         /* *sb_block = match_int(&args[0]); */
 341                         break;
 342                 case Opt_err_panic:
 343                         kind = EXT2_MOUNT_ERRORS_PANIC;
 344                         break;
 345                 case Opt_err_ro:
 346                         kind = EXT2_MOUNT_ERRORS_RO;
 347                         break;
 348                 case Opt_err_cont:
 349                         kind = EXT2_MOUNT_ERRORS_CONT;
 350                         break;
 351                 case Opt_nouid32:
 352                         set_opt (sbi->s_mount_opt, NO_UID32);
 353                         break;
 354                 case Opt_check:
 355 #ifdef CONFIG_EXT2_CHECK
 356                         set_opt (sbi->s_mount_opt, CHECK);
 357 #else
 358                         printk("EXT2 Check option not supported\n");
 359 #endif
 360                         break;
 361                 case Opt_nocheck:
 362                         clear_opt (sbi->s_mount_opt, CHECK);
 363                         break;
 364                 case Opt_debug:
 365                         set_opt (sbi->s_mount_opt, DEBUG);
 366                         break;
 367                 case Opt_oldalloc:
 368                         set_opt (sbi->s_mount_opt, OLDALLOC);
 369                         break;
 370                 case Opt_orlov:
 371                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 372                         break;
 373                 case Opt_nobh:
 374                         set_opt (sbi->s_mount_opt, NOBH);
 375                         break;
 376 #ifdef CONFIG_EXT2_FS_XATTR
 377                 case Opt_user_xattr:
 378                         set_opt (sbi->s_mount_opt, XATTR_USER);
 379                         break;
 380                 case Opt_nouser_xattr:
 381                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 382                         break;
 383 #else
 384                 case Opt_user_xattr:
 385                 case Opt_nouser_xattr:
 386                         printk("EXT2 (no)user_xattr options not supported\n");
 387                         break;
 388 #endif
 389 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 390                 case Opt_acl:
 391                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 392                         break;
 393                 case Opt_noacl:
 394                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 395                         break;
 396 #else
 397                 case Opt_acl:
 398                 case Opt_noacl:
 399                         printk("EXT2 (no)acl options not supported\n");
 400                         break;
 401 #endif
 402                 case Opt_ignore:
 403                         break;
 404                 default:
 405                         return 0;
 406                 }
 407         }
 408         sbi->s_mount_opt |= kind;
 409         return 1;
 410 }
 411
 412 static int ext2_setup_super (struct super_block * sb,
 413                               struct ext2_super_block * es,
 414                               int read_only)
 415 {
 416         int res = 0;
 417         struct ext2_sb_info *sbi = EXT2_SB(sb);
 418
 419         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 420                 printk ("EXT2-fs warning: revision level too high, "
 421                         "forcing read-only mode\n");
 422                 res = MS_RDONLY;
 423         }
 424         if (read_only)
 425                 return res;
 426         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 427                 printk ("EXT2-fs warning: mounting unchecked fs, "
 428                         "running e2fsck is recommended\n");
 429         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 430                 printk ("EXT2-fs warning: mounting fs with errors, "
 431                         "running e2fsck is recommended\n");
 432         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 433                  le16_to_cpu(es->s_mnt_count) >=
 434                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 435                 printk ("EXT2-fs warning: maximal mount count reached, "
 436                         "running e2fsck is recommended\n");
 437         else if (le32_to_cpu(es->s_checkinterval) &&
 438                 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 439                 printk ("EXT2-fs warning: checktime reached, "
 440                         "running e2fsck is recommended\n");
 441         if (!le16_to_cpu(es->s_max_mnt_count))
 442                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 443         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
 444         ext2_write_super(sb);
 445         if (test_opt (sb, DEBUG))
 446                 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
 447                         "bpg=%lu, ipg=%lu, mo=%04lx]\n",
 448                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 449                         sbi->s_frag_size,
 450                         sbi->s_groups_count,
 451                         EXT2_BLOCKS_PER_GROUP(sb),
 452                         EXT2_INODES_PER_GROUP(sb),
 453                         sbi->s_mount_opt);
 454 #ifdef CONFIG_EXT2_CHECK
 455         if (test_opt (sb, CHECK)) {
 456                 ext2_check_blocks_bitmap (sb);
 457                 ext2_check_inodes_bitmap (sb);
 458         }
 459 #endif
 460         return res;
 461 }
 462
 463 static int ext2_check_descriptors (struct super_block * sb)
 464 {
 465         int i;
 466         int desc_block = 0;
 467         struct ext2_sb_info *sbi = EXT2_SB(sb);
 468         unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
 469         struct ext2_group_desc * gdp = NULL;
 470
 471         ext2_debug ("Checking group descriptors");
 472
 473         for (i = 0; i < sbi->s_groups_count; i++)
 474         {
 475                 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
 476                         gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
 477                 if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
 478                     le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
 479                 {
 480                         ext2_error (sb, "ext2_check_descriptors",
 481                                     "Block bitmap for group %d"
 482                                     " not in group (block %lu)!",
 483                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 484                         return 0;
 485                 }
 486                 if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
 487                     le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
 488                 {
 489                         ext2_error (sb, "ext2_check_descriptors",
 490                                     "Inode bitmap for group %d"
 491                                     " not in group (block %lu)!",
 492                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 493                         return 0;
 494                 }
 495                 if (le32_to_cpu(gdp->bg_inode_table) < block ||
 496                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
 497                     block + EXT2_BLOCKS_PER_GROUP(sb))
 498                 {
 499                         ext2_error (sb, "ext2_check_descriptors",
 500                                     "Inode table for group %d"
 501                                     " not in group (block %lu)!",
 502                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 503                         return 0;
 504                 }
 505                 block += EXT2_BLOCKS_PER_GROUP(sb);
 506                 gdp++;
 507         }
 508         return 1;
 509 }
 510
 511 #define log2(n) ffz(~(n))
 512
 513 /*
 514  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 515  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 516  * We need to be 1 filesystem block less than the 2^32 sector limit.
 517  */
 518 static loff_t ext2_max_size(int bits)
 519 {
 520         loff_t res = EXT2_NDIR_BLOCKS;
 521         /* This constant is calculated to be the largest file size for a
 522          * dense, 4k-blocksize file such that the total number of
 523          * sectors in the file, including data and all indirect blocks,
 524          * does not exceed 2^32. */
 525         const loff_t upper_limit = 0x1ff7fffd000LL;
 526
 527         res += 1LL << (bits-2);
 528         res += 1LL << (2*(bits-2));
 529         res += 1LL << (3*(bits-2));
 530         res <<= bits;
 531         if (res > upper_limit)
 532                 res = upper_limit;
 533         return res;
 534 }
 535
 536 static unsigned long descriptor_loc(struct super_block *sb,
 537                                     unsigned long logic_sb_block,
 538                                     int nr)
 539 {
 540         struct ext2_sb_info *sbi = EXT2_SB(sb);
 541         unsigned long bg, first_data_block, first_meta_bg;
 542         int has_super = 0;
 543
 544         first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
 545         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 546
 547         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 548             nr < first_meta_bg)
 549                 return (logic_sb_block + nr + 1);
 550         bg = sbi->s_desc_per_block * nr;
 551         if (ext2_bg_has_super(sb, bg))
 552                 has_super = 1;
 553         return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
 554 }
 555
 556 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 557 {
 558         struct buffer_head * bh;
 559         struct ext2_sb_info * sbi;
 560         struct ext2_super_block * es;
 561         struct inode *root;
 562         unsigned long block;
 563         unsigned long sb_block = get_sb_block(&data);
 564         unsigned long logic_sb_block;
 565         unsigned long offset = 0;
 566         unsigned long def_mount_opts;
 567         int blocksize = BLOCK_SIZE;
 568         int db_count;
 569         int i, j;
 570         __le32 features;
 571
 572         sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
 573         if (!sbi)
 574                 return -ENOMEM;
 575         sb->s_fs_info = sbi;
 576         memset(sbi, 0, sizeof(*sbi));
 577
 578         /*
 579          * See what the current blocksize for the device is, and
 580          * use that as the blocksize.  Otherwise (or if the blocksize
 581          * is smaller than the default) use the default.
 582          * This is important for devices that have a hardware
 583          * sectorsize that is larger than the default.
 584          */
 585         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 586         if (!blocksize) {
 587                 printk ("EXT2-fs: unable to set blocksize\n");
 588                 goto failed_sbi;
 589         }
 590
 591         /*
 592          * If the superblock doesn't start on a hardware sector boundary,
 593          * calculate the offset.
 594          */
 595         if (blocksize != BLOCK_SIZE) {
 596                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 597                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 598         } else {
 599                 logic_sb_block = sb_block;
 600         }
 601
 602         if (!(bh = sb_bread(sb, logic_sb_block))) {
 603                 printk ("EXT2-fs: unable to read superblock\n");
 604                 goto failed_sbi;
 605         }
 606         /*
 607          * Note: s_es must be initialized as soon as possible because
 608          *       some ext2 macro-instructions depend on its value
 609          */
 610         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 611         sbi->s_es = es;
 612         sb->s_magic = le16_to_cpu(es->s_magic);
 613
 614         if (sb->s_magic != EXT2_SUPER_MAGIC)
 615                 goto cantfind_ext2;
 616
 617         /* Set defaults before we parse the mount options */
 618         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 619         if (def_mount_opts & EXT2_DEFM_DEBUG)
 620                 set_opt(sbi->s_mount_opt, DEBUG);
 621         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 622                 set_opt(sbi->s_mount_opt, GRPID);
 623         if (def_mount_opts & EXT2_DEFM_UID16)
 624                 set_opt(sbi->s_mount_opt, NO_UID32);
 625         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 626                 set_opt(sbi->s_mount_opt, XATTR_USER);
 627         if (def_mount_opts & EXT2_DEFM_ACL)
 628                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 629
 630         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 631                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 632         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
 633                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 634
 635         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 636         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 637
 638         if (!parse_options ((char *) data, sbi))
 639                 goto failed_mount;
 640
 641         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 642                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 643                  MS_POSIXACL : 0);
 644
 645         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 646             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 647              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 648              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 649                 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
 650                        "running e2fsck is recommended\n");
 651         /*
 652          * Check feature flags regardless of the revision level, since we
 653          * previously didn't change the revision level when setting the flags,
 654          * so there is a chance incompat flags are set on a rev 0 filesystem.
 655          */
 656         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 657         if (features) {
 658                 printk("EXT2-fs: %s: couldn't mount because of "
 659                        "unsupported optional features (%x).\n",
 660                        sb->s_id, le32_to_cpu(features));
 661                 goto failed_mount;
 662         }
 663         if (!(sb->s_flags & MS_RDONLY) &&
 664             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 665                 printk("EXT2-fs: %s: couldn't mount RDWR because of "
 666                        "unsupported optional features (%x).\n",
 667                        sb->s_id, le32_to_cpu(features));
 668                 goto failed_mount;
 669         }
 670
 671         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 672
 673         /* If the blocksize doesn't match, re-read the thing.. */
 674         if (sb->s_blocksize != blocksize) {
 675                 brelse(bh);
 676
 677                 if (!sb_set_blocksize(sb, blocksize)) {
 678                         printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
 679                         goto failed_sbi;
 680                 }
 681
 682                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 683                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 684                 bh = sb_bread(sb, logic_sb_block);
 685                 if(!bh) {
 686                         printk("EXT2-fs: Couldn't read superblock on "
 687                                "2nd try.\n");
 688                         goto failed_sbi;
 689                 }
 690                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 691                 sbi->s_es = es;
 692                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 693                         printk ("EXT2-fs: Magic mismatch, very weird !\n");
 694                         goto failed_mount;
 695                 }
 696         }
 697
 698         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 699
 700         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 701                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 702                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 703         } else {
 704                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 705                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 706                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 707                     (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
 708                     (sbi->s_inode_size > blocksize)) {
 709                         printk ("EXT2-fs: unsupported inode size: %d\n",
 710                                 sbi->s_inode_size);
 711                         goto failed_mount;
 712                 }
 713         }
 714
 715         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 716                                    le32_to_cpu(es->s_log_frag_size);
 717         if (sbi->s_frag_size == 0)
 718                 goto cantfind_ext2;
 719         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 720
 721         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 722         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 723         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 724
 725         if (EXT2_INODE_SIZE(sb) == 0)
 726                 goto cantfind_ext2;
 727         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 728         if (sbi->s_inodes_per_block == 0)
 729                 goto cantfind_ext2;
 730         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 731                                         sbi->s_inodes_per_block;
 732         sbi->s_desc_per_block = sb->s_blocksize /
 733                                         sizeof (struct ext2_group_desc);
 734         sbi->s_sbh = bh;
 735         sbi->s_mount_state = le16_to_cpu(es->s_state);
 736         sbi->s_addr_per_block_bits =
 737                 log2 (EXT2_ADDR_PER_BLOCK(sb));
 738         sbi->s_desc_per_block_bits =
 739                 log2 (EXT2_DESC_PER_BLOCK(sb));
 740
 741         if (sb->s_magic != EXT2_SUPER_MAGIC)
 742                 goto cantfind_ext2;
 743
 744         if (sb->s_blocksize != bh->b_size) {
 745                 if (!silent)
 746                         printk ("VFS: Unsupported blocksize on dev "
 747                                 "%s.\n", sb->s_id);
 748                 goto failed_mount;
 749         }
 750
 751         if (sb->s_blocksize != sbi->s_frag_size) {
 752                 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
 753                         sbi->s_frag_size, sb->s_blocksize);
 754                 goto failed_mount;
 755         }
 756
 757         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 758                 printk ("EXT2-fs: #blocks per group too big: %lu\n",
 759                         sbi->s_blocks_per_group);
 760                 goto failed_mount;
 761         }
 762         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 763                 printk ("EXT2-fs: #fragments per group too big: %lu\n",
 764                         sbi->s_frags_per_group);
 765                 goto failed_mount;
 766         }
 767         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 768                 printk ("EXT2-fs: #inodes per group too big: %lu\n",
 769                         sbi->s_inodes_per_group);
 770                 goto failed_mount;
 771         }
 772
 773         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 774                 goto cantfind_ext2;
 775         sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
 776                                         le32_to_cpu(es->s_first_data_block) +
 777                                        EXT2_BLOCKS_PER_GROUP(sb) - 1) /
 778                                        EXT2_BLOCKS_PER_GROUP(sb);
 779         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 780                    EXT2_DESC_PER_BLOCK(sb);
 781         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
 782         if (sbi->s_group_desc == NULL) {
 783                 printk ("EXT2-fs: not enough memory\n");
 784                 goto failed_mount;
 785         }
 786         percpu_counter_init(&sbi->s_freeblocks_counter);
 787         percpu_counter_init(&sbi->s_freeinodes_counter);
 788         percpu_counter_init(&sbi->s_dirs_counter);
 789         bgl_lock_init(&sbi->s_blockgroup_lock);
 790         sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
 791                                GFP_KERNEL);
 792         if (!sbi->s_debts) {
 793                 printk ("EXT2-fs: not enough memory\n");
 794                 goto failed_mount_group_desc;
 795         }
 796         memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
 797         for (i = 0; i < db_count; i++) {
 798                 block = descriptor_loc(sb, logic_sb_block, i);
 799                 sbi->s_group_desc[i] = sb_bread(sb, block);
 800                 if (!sbi->s_group_desc[i]) {
 801                         for (j = 0; j < i; j++)
 802                                 brelse (sbi->s_group_desc[j]);
 803                         printk ("EXT2-fs: unable to read group descriptors\n");
 804                         goto failed_mount_group_desc;
 805                 }
 806         }
 807         if (!ext2_check_descriptors (sb)) {
 808                 printk ("EXT2-fs: group descriptors corrupted!\n");
 809                 db_count = i;
 810                 goto failed_mount2;
 811         }
 812         sbi->s_gdb_count = db_count;
 813         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 814         spin_lock_init(&sbi->s_next_gen_lock);
 815         /*
 816          * set up enough so that it can read an inode
 817          */
 818         sb->s_op = &ext2_sops;
 819         sb->s_export_op = &ext2_export_ops;
 820         sb->s_xattr = ext2_xattr_handlers;
 821         root = iget(sb, EXT2_ROOT_INO);
 822         sb->s_root = d_alloc_root(root);
 823         if (!sb->s_root) {
 824                 iput(root);
 825                 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
 826                 goto failed_mount2;
 827         }
 828         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
 829                 dput(sb->s_root);
 830                 sb->s_root = NULL;
 831                 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
 832                 goto failed_mount2;
 833         }
 834         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 835                 ext2_warning(sb, __FUNCTION__,
 836                         "mounting ext3 filesystem as ext2\n");
 837         ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
 838         percpu_counter_mod(&sbi->s_freeblocks_counter,
 839                                 ext2_count_free_blocks(sb));
 840         percpu_counter_mod(&sbi->s_freeinodes_counter,
 841                                 ext2_count_free_inodes(sb));
 842         percpu_counter_mod(&sbi->s_dirs_counter,
 843                                 ext2_count_dirs(sb));
 844         return 0;
 845
 846 cantfind_ext2:
 847         if (!silent)
 848                 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
 849                        sb->s_id);
 850         goto failed_mount;
 851
 852 failed_mount2:
 853         for (i = 0; i < db_count; i++)
 854                 brelse(sbi->s_group_desc[i]);
 855 failed_mount_group_desc:
 856         kfree(sbi->s_group_desc);
 857         kfree(sbi->s_debts);
 858 failed_mount:
 859         brelse(bh);
 860 failed_sbi:
 861         sb->s_fs_info = NULL;
 862         kfree(sbi);
 863         return -EINVAL;
 864 }
 865
 866 static void ext2_commit_super (struct super_block * sb,
 867                                struct ext2_super_block * es)
 868 {
 869         es->s_wtime = cpu_to_le32(get_seconds());
 870         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
 871         sb->s_dirt = 0;
 872 }
 873
 874 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
 875 {
 876         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
 877         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
 878         es->s_wtime = cpu_to_le32(get_seconds());
 879         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
 880         sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
 881         sb->s_dirt = 0;
 882 }
 883
 884 /*
 885  * In the second extended file system, it is not necessary to
 886  * write the super block since we use a mapping of the
 887  * disk super block in a buffer.
 888  *
 889  * However, this function is still used to set the fs valid
 890  * flags to 0.  We need to set this flag to 0 since the fs
 891  * may have been checked while mounted and e2fsck may have
 892  * set s_state to EXT2_VALID_FS after some corrections.
 893  */
 894
 895 void ext2_write_super (struct super_block * sb)
 896 {
 897         struct ext2_super_block * es;
 898         lock_kernel();
 899         if (!(sb->s_flags & MS_RDONLY)) {
 900                 es = EXT2_SB(sb)->s_es;
 901
 902                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
 903                         ext2_debug ("setting valid to 0\n");
 904                         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
 905                                                   ~EXT2_VALID_FS);
 906                         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
 907                         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
 908                         es->s_mtime = cpu_to_le32(get_seconds());
 909                         ext2_sync_super(sb, es);
 910                 } else
 911                         ext2_commit_super (sb, es);
 912         }
 913         sb->s_dirt = 0;
 914         unlock_kernel();
 915 }
 916
 917 static int ext2_remount (struct super_block * sb, int * flags, char * data)
 918 {
 919         struct ext2_sb_info * sbi = EXT2_SB(sb);
 920         struct ext2_super_block * es;
 921
 922         /*
 923          * Allow the "check" option to be passed as a remount option.
 924          */
 925         if (!parse_options (data, sbi))
 926                 return -EINVAL;
 927
 928         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 929                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
 930
 931         es = sbi->s_es;
 932         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 933                 return 0;
 934         if (*flags & MS_RDONLY) {
 935                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
 936                     !(sbi->s_mount_state & EXT2_VALID_FS))
 937                         return 0;
 938                 /*
 939                  * OK, we are remounting a valid rw partition rdonly, so set
 940                  * the rdonly flag and then mark the partition as valid again.
 941                  */
 942                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 943                 es->s_mtime = cpu_to_le32(get_seconds());
 944         } else {
 945                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
 946                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
 947                 if (ret) {
 948                         printk("EXT2-fs: %s: couldn't remount RDWR because of "
 949                                "unsupported optional features (%x).\n",
 950                                sb->s_id, le32_to_cpu(ret));
 951                         return -EROFS;
 952                 }
 953                 /*
 954                  * Mounting a RDONLY partition read-write, so reread and
 955                  * store the current valid flag.  (It may have been changed
 956                  * by e2fsck since we originally mounted the partition.)
 957                  */
 958                 sbi->s_mount_state = le16_to_cpu(es->s_state);
 959                 if (!ext2_setup_super (sb, es, 0))
 960                         sb->s_flags &= ~MS_RDONLY;
 961         }
 962         ext2_sync_super(sb, es);
 963         return 0;
 964 }
 965
 966 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf)
 967 {
 968         struct ext2_sb_info *sbi = EXT2_SB(sb);
 969         unsigned long overhead;
 970         int i;
 971
 972         if (test_opt (sb, MINIX_DF))
 973                 overhead = 0;
 974         else {
 975                 /*
 976                  * Compute the overhead (FS structures)
 977                  */
 978
 979                 /*
 980                  * All of the blocks before first_data_block are
 981                  * overhead
 982                  */
 983                 overhead = le32_to_cpu(sbi->s_es->s_first_data_block);
 984
 985                 /*
 986                  * Add the overhead attributed to the superblock and
 987                  * block group descriptors.  If the sparse superblocks
 988                  * feature is turned on, then not all groups have this.
 989                  */
 990                 for (i = 0; i < sbi->s_groups_count; i++)
 991                         overhead += ext2_bg_has_super(sb, i) +
 992                                 ext2_bg_num_gdb(sb, i);
 993
 994                 /*
 995                  * Every block group has an inode bitmap, a block
 996                  * bitmap, and an inode table.
 997                  */
 998                 overhead += (sbi->s_groups_count *
 999                              (2 + sbi->s_itb_per_group));
1000         }
1001
1002         buf->f_type = EXT2_SUPER_MAGIC;
1003         buf->f_bsize = sb->s_blocksize;
1004         buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead;
1005         buf->f_bfree = ext2_count_free_blocks(sb);
1006         buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count);
1007         if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count))
1008                 buf->f_bavail = 0;
1009         buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count);
1010         buf->f_ffree = ext2_count_free_inodes (sb);
1011         buf->f_namelen = EXT2_NAME_LEN;
1012         return 0;
1013 }
1014
1015 static struct super_block *ext2_get_sb(struct file_system_type *fs_type,
1016         int flags, const char *dev_name, void *data)
1017 {
1018         return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1019 }
1020
1021 #ifdef CONFIG_QUOTA
1022
1023 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1024  * acquiring the locks... As quota files are never truncated and quota code
1025  * itself serializes the operations (and noone else should touch the files)
1026  * we don't have to be afraid of races */
1027 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1028                                size_t len, loff_t off)
1029 {
1030         struct inode *inode = sb_dqopt(sb)->files[type];
1031         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1032         int err = 0;
1033         int offset = off & (sb->s_blocksize - 1);
1034         int tocopy;
1035         size_t toread;
1036         struct buffer_head tmp_bh;
1037         struct buffer_head *bh;
1038         loff_t i_size = i_size_read(inode);
1039
1040         if (off > i_size)
1041                 return 0;
1042         if (off+len > i_size)
1043                 len = i_size-off;
1044         toread = len;
1045         while (toread > 0) {
1046                 tocopy = sb->s_blocksize - offset < toread ?
1047                                 sb->s_blocksize - offset : toread;
1048
1049                 tmp_bh.b_state = 0;
1050                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1051                 if (err)
1052                         return err;
1053                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1054                         memset(data, 0, tocopy);
1055                 else {
1056                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1057                         if (!bh)
1058                                 return -EIO;
1059                         memcpy(data, bh->b_data+offset, tocopy);
1060                         brelse(bh);
1061                 }
1062                 offset = 0;
1063                 toread -= tocopy;
1064                 data += tocopy;
1065                 blk++;
1066         }
1067         return len;
1068 }
1069
1070 /* Write to quotafile */
1071 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1072                                 const char *data, size_t len, loff_t off)
1073 {
1074         struct inode *inode = sb_dqopt(sb)->files[type];
1075         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1076         int err = 0;
1077         int offset = off & (sb->s_blocksize - 1);
1078         int tocopy;
1079         size_t towrite = len;
1080         struct buffer_head tmp_bh;
1081         struct buffer_head *bh;
1082
1083         down(&inode->i_sem);
1084         while (towrite > 0) {
1085                 tocopy = sb->s_blocksize - offset < towrite ?
1086                                 sb->s_blocksize - offset : towrite;
1087
1088                 tmp_bh.b_state = 0;
1089                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1090                 if (err)
1091                         goto out;
1092                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1093                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1094                 else
1095                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1096                 if (!bh) {
1097                         err = -EIO;
1098                         goto out;
1099                 }
1100                 lock_buffer(bh);
1101                 memcpy(bh->b_data+offset, data, tocopy);
1102                 flush_dcache_page(bh->b_page);
1103                 set_buffer_uptodate(bh);
1104                 mark_buffer_dirty(bh);
1105                 unlock_buffer(bh);
1106                 brelse(bh);
1107                 offset = 0;
1108                 towrite -= tocopy;
1109                 data += tocopy;
1110                 blk++;
1111         }
1112 out:
1113         if (len == towrite)
1114                 return err;
1115         if (inode->i_size < off+len-towrite)
1116                 i_size_write(inode, off+len-towrite);
1117         inode->i_version++;
1118         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1119         mark_inode_dirty(inode);
1120         up(&inode->i_sem);
1121         return len - towrite;
1122 }
1123
1124 #endif
1125
1126 static struct file_system_type ext2_fs_type = {
1127         .owner          = THIS_MODULE,
1128         .name           = "ext2",
1129         .get_sb         = ext2_get_sb,
1130         .kill_sb        = kill_block_super,
1131         .fs_flags       = FS_REQUIRES_DEV,
1132 };
1133
1134 static int __init init_ext2_fs(void)
1135 {
1136         int err = init_ext2_xattr();
1137         if (err)
1138                 return err;
1139         err = init_inodecache();
1140         if (err)
1141                 goto out1;
1142         err = register_filesystem(&ext2_fs_type);
1143         if (err)
1144                 goto out;
1145         return 0;
1146 out:
1147         destroy_inodecache();
1148 out1:
1149         exit_ext2_xattr();
1150         return err;
1151 }
1152
1153 static void __exit exit_ext2_fs(void)
1154 {
1155         unregister_filesystem(&ext2_fs_type);
1156         destroy_inodecache();
1157         exit_ext2_xattr();
1158 }
1159
1160 module_init(init_ext2_fs)
1161 module_exit(exit_ext2_fs)