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 #include "xip.h"
  35
  36 static void ext2_sync_super(struct super_block *sb,
  37                             struct ext2_super_block *es);
  38 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  39 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf);
  40
  41 void ext2_error (struct super_block * sb, const char * function,
  42                  const char * fmt, ...)
  43 {
  44         va_list args;
  45         struct ext2_sb_info *sbi = EXT2_SB(sb);
  46         struct ext2_super_block *es = sbi->s_es;
  47
  48         if (!(sb->s_flags & MS_RDONLY)) {
  49                 sbi->s_mount_state |= EXT2_ERROR_FS;
  50                 es->s_state =
  51                         cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
  52                 ext2_sync_super(sb, es);
  53         }
  54
  55         va_start(args, fmt);
  56         printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
  57         vprintk(fmt, args);
  58         printk("\n");
  59         va_end(args);
  60
  61         if (test_opt(sb, ERRORS_PANIC))
  62                 panic("EXT2-fs panic from previous error\n");
  63         if (test_opt(sb, ERRORS_RO)) {
  64                 printk("Remounting filesystem read-only\n");
  65                 sb->s_flags |= MS_RDONLY;
  66         }
  67 }
  68
  69 void ext2_warning (struct super_block * sb, const char * function,
  70                    const char * fmt, ...)
  71 {
  72         va_list args;
  73
  74         va_start(args, fmt);
  75         printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
  76                sb->s_id, function);
  77         vprintk(fmt, args);
  78         printk("\n");
  79         va_end(args);
  80 }
  81
  82 void ext2_update_dynamic_rev(struct super_block *sb)
  83 {
  84         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
  85
  86         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
  87                 return;
  88
  89         ext2_warning(sb, __FUNCTION__,
  90                      "updating to rev %d because of new feature flag, "
  91                      "running e2fsck is recommended",
  92                      EXT2_DYNAMIC_REV);
  93
  94         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
  95         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
  96         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
  97         /* leave es->s_feature_*compat flags alone */
  98         /* es->s_uuid will be set by e2fsck if empty */
  99
 100         /*
 101          * The rest of the superblock fields should be zero, and if not it
 102          * means they are likely already in use, so leave them alone.  We
 103          * can leave it up to e2fsck to clean up any inconsistencies there.
 104          */
 105 }
 106
 107 static void ext2_put_super (struct super_block * sb)
 108 {
 109         int db_count;
 110         int i;
 111         struct ext2_sb_info *sbi = EXT2_SB(sb);
 112
 113         ext2_xattr_put_super(sb);
 114         if (!(sb->s_flags & MS_RDONLY)) {
 115                 struct ext2_super_block *es = sbi->s_es;
 116
 117                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 118                 ext2_sync_super(sb, es);
 119         }
 120         db_count = sbi->s_gdb_count;
 121         for (i = 0; i < db_count; i++)
 122                 if (sbi->s_group_desc[i])
 123                         brelse (sbi->s_group_desc[i]);
 124         kfree(sbi->s_group_desc);
 125         kfree(sbi->s_debts);
 126         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 127         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 128         percpu_counter_destroy(&sbi->s_dirs_counter);
 129         brelse (sbi->s_sbh);
 130         sb->s_fs_info = NULL;
 131         kfree(sbi);
 132
 133         return;
 134 }
 135
 136 static kmem_cache_t * ext2_inode_cachep;
 137
 138 static struct inode *ext2_alloc_inode(struct super_block *sb)
 139 {
 140         struct ext2_inode_info *ei;
 141         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL);
 142         if (!ei)
 143                 return NULL;
 144 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 145         ei->i_acl = EXT2_ACL_NOT_CACHED;
 146         ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 147 #endif
 148         ei->vfs_inode.i_version = 1;
 149         return &ei->vfs_inode;
 150 }
 151
 152 static void ext2_destroy_inode(struct inode *inode)
 153 {
 154         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 155 }
 156
 157 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
 158 {
 159         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 160
 161         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 162             SLAB_CTOR_CONSTRUCTOR) {
 163                 rwlock_init(&ei->i_meta_lock);
 164 #ifdef CONFIG_EXT2_FS_XATTR
 165                 init_rwsem(&ei->xattr_sem);
 166 #endif
 167                 inode_init_once(&ei->vfs_inode);
 168         }
 169 }
 170
 171 static int init_inodecache(void)
 172 {
 173         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 174                                              sizeof(struct ext2_inode_info),
 175                                              0, SLAB_RECLAIM_ACCOUNT,
 176                                              init_once, NULL);
 177         if (ext2_inode_cachep == NULL)
 178                 return -ENOMEM;
 179         return 0;
 180 }
 181
 182 static void destroy_inodecache(void)
 183 {
 184         if (kmem_cache_destroy(ext2_inode_cachep))
 185                 printk(KERN_INFO "ext2_inode_cache: not all structures were freed\n");
 186 }
 187
 188 static void ext2_clear_inode(struct inode *inode)
 189 {
 190 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 191         struct ext2_inode_info *ei = EXT2_I(inode);
 192
 193         if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
 194                 posix_acl_release(ei->i_acl);
 195                 ei->i_acl = EXT2_ACL_NOT_CACHED;
 196         }
 197         if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
 198                 posix_acl_release(ei->i_default_acl);
 199                 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 200         }
 201 #endif
 202 }
 203
 204 #ifdef CONFIG_QUOTA
 205 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 206 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 207 #endif
 208
 209 static struct super_operations ext2_sops = {
 210         .alloc_inode    = ext2_alloc_inode,
 211         .destroy_inode  = ext2_destroy_inode,
 212         .read_inode     = ext2_read_inode,
 213         .write_inode    = ext2_write_inode,
 214         .put_inode      = ext2_put_inode,
 215         .delete_inode   = ext2_delete_inode,
 216         .put_super      = ext2_put_super,
 217         .write_super    = ext2_write_super,
 218         .statfs         = ext2_statfs,
 219         .remount_fs     = ext2_remount,
 220         .clear_inode    = ext2_clear_inode,
 221 #ifdef CONFIG_QUOTA
 222         .quota_read     = ext2_quota_read,
 223         .quota_write    = ext2_quota_write,
 224 #endif
 225 };
 226
 227 /* Yes, most of these are left as NULL!!
 228  * A NULL value implies the default, which works with ext2-like file
 229  * systems, but can be improved upon.
 230  * Currently only get_parent is required.
 231  */
 232 struct dentry *ext2_get_parent(struct dentry *child);
 233 static struct export_operations ext2_export_ops = {
 234         .get_parent = ext2_get_parent,
 235 };
 236
 237 static unsigned long get_sb_block(void **data)
 238 {
 239         unsigned long   sb_block;
 240         char            *options = (char *) *data;
 241
 242         if (!options || strncmp(options, "sb=", 3) != 0)
 243                 return 1;       /* Default location */
 244         options += 3;
 245         sb_block = simple_strtoul(options, &options, 0);
 246         if (*options && *options != ',') {
 247                 printk("EXT2-fs: Invalid sb specification: %s\n",
 248                        (char *) *data);
 249                 return 1;
 250         }
 251         if (*options == ',')
 252                 options++;
 253         *data = (void *) options;
 254         return sb_block;
 255 }
 256
 257 enum {
 258         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 259         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
 260         Opt_nouid32, Opt_check, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov, Opt_nobh,
 261         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl, Opt_xip,
 262         Opt_ignore, Opt_err,
 263 };
 264
 265 static match_table_t tokens = {
 266         {Opt_bsd_df, "bsddf"},
 267         {Opt_minix_df, "minixdf"},
 268         {Opt_grpid, "grpid"},
 269         {Opt_grpid, "bsdgroups"},
 270         {Opt_nogrpid, "nogrpid"},
 271         {Opt_nogrpid, "sysvgroups"},
 272         {Opt_resgid, "resgid=%u"},
 273         {Opt_resuid, "resuid=%u"},
 274         {Opt_sb, "sb=%u"},
 275         {Opt_err_cont, "errors=continue"},
 276         {Opt_err_panic, "errors=panic"},
 277         {Opt_err_ro, "errors=remount-ro"},
 278         {Opt_nouid32, "nouid32"},
 279         {Opt_nocheck, "check=none"},
 280         {Opt_nocheck, "nocheck"},
 281         {Opt_check, "check"},
 282         {Opt_debug, "debug"},
 283         {Opt_oldalloc, "oldalloc"},
 284         {Opt_orlov, "orlov"},
 285         {Opt_nobh, "nobh"},
 286         {Opt_user_xattr, "user_xattr"},
 287         {Opt_nouser_xattr, "nouser_xattr"},
 288         {Opt_acl, "acl"},
 289         {Opt_noacl, "noacl"},
 290         {Opt_xip, "xip"},
 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_xip:
 403 #ifdef CONFIG_EXT2_FS_XIP
 404                         set_opt (sbi->s_mount_opt, XIP);
 405 #else
 406                         printk("EXT2 xip option not supported\n");
 407 #endif
 408                         break;
 409                 case Opt_ignore:
 410                         break;
 411                 default:
 412                         return 0;
 413                 }
 414         }
 415         sbi->s_mount_opt |= kind;
 416         return 1;
 417 }
 418
 419 static int ext2_setup_super (struct super_block * sb,
 420                               struct ext2_super_block * es,
 421                               int read_only)
 422 {
 423         int res = 0;
 424         struct ext2_sb_info *sbi = EXT2_SB(sb);
 425
 426         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 427                 printk ("EXT2-fs warning: revision level too high, "
 428                         "forcing read-only mode\n");
 429                 res = MS_RDONLY;
 430         }
 431         if (read_only)
 432                 return res;
 433         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 434                 printk ("EXT2-fs warning: mounting unchecked fs, "
 435                         "running e2fsck is recommended\n");
 436         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 437                 printk ("EXT2-fs warning: mounting fs with errors, "
 438                         "running e2fsck is recommended\n");
 439         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 440                  le16_to_cpu(es->s_mnt_count) >=
 441                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 442                 printk ("EXT2-fs warning: maximal mount count reached, "
 443                         "running e2fsck is recommended\n");
 444         else if (le32_to_cpu(es->s_checkinterval) &&
 445                 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 446                 printk ("EXT2-fs warning: checktime reached, "
 447                         "running e2fsck is recommended\n");
 448         if (!le16_to_cpu(es->s_max_mnt_count))
 449                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 450         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
 451         ext2_write_super(sb);
 452         if (test_opt (sb, DEBUG))
 453                 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
 454                         "bpg=%lu, ipg=%lu, mo=%04lx]\n",
 455                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 456                         sbi->s_frag_size,
 457                         sbi->s_groups_count,
 458                         EXT2_BLOCKS_PER_GROUP(sb),
 459                         EXT2_INODES_PER_GROUP(sb),
 460                         sbi->s_mount_opt);
 461 #ifdef CONFIG_EXT2_CHECK
 462         if (test_opt (sb, CHECK)) {
 463                 ext2_check_blocks_bitmap (sb);
 464                 ext2_check_inodes_bitmap (sb);
 465         }
 466 #endif
 467         return res;
 468 }
 469
 470 static int ext2_check_descriptors (struct super_block * sb)
 471 {
 472         int i;
 473         int desc_block = 0;
 474         struct ext2_sb_info *sbi = EXT2_SB(sb);
 475         unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
 476         struct ext2_group_desc * gdp = NULL;
 477
 478         ext2_debug ("Checking group descriptors");
 479
 480         for (i = 0; i < sbi->s_groups_count; i++)
 481         {
 482                 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
 483                         gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
 484                 if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
 485                     le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
 486                 {
 487                         ext2_error (sb, "ext2_check_descriptors",
 488                                     "Block bitmap for group %d"
 489                                     " not in group (block %lu)!",
 490                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 491                         return 0;
 492                 }
 493                 if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
 494                     le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
 495                 {
 496                         ext2_error (sb, "ext2_check_descriptors",
 497                                     "Inode bitmap for group %d"
 498                                     " not in group (block %lu)!",
 499                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 500                         return 0;
 501                 }
 502                 if (le32_to_cpu(gdp->bg_inode_table) < block ||
 503                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
 504                     block + EXT2_BLOCKS_PER_GROUP(sb))
 505                 {
 506                         ext2_error (sb, "ext2_check_descriptors",
 507                                     "Inode table for group %d"
 508                                     " not in group (block %lu)!",
 509                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 510                         return 0;
 511                 }
 512                 block += EXT2_BLOCKS_PER_GROUP(sb);
 513                 gdp++;
 514         }
 515         return 1;
 516 }
 517
 518 #define log2(n) ffz(~(n))
 519
 520 /*
 521  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 522  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 523  * We need to be 1 filesystem block less than the 2^32 sector limit.
 524  */
 525 static loff_t ext2_max_size(int bits)
 526 {
 527         loff_t res = EXT2_NDIR_BLOCKS;
 528         /* This constant is calculated to be the largest file size for a
 529          * dense, 4k-blocksize file such that the total number of
 530          * sectors in the file, including data and all indirect blocks,
 531          * does not exceed 2^32. */
 532         const loff_t upper_limit = 0x1ff7fffd000LL;
 533
 534         res += 1LL << (bits-2);
 535         res += 1LL << (2*(bits-2));
 536         res += 1LL << (3*(bits-2));
 537         res <<= bits;
 538         if (res > upper_limit)
 539                 res = upper_limit;
 540         return res;
 541 }
 542
 543 static unsigned long descriptor_loc(struct super_block *sb,
 544                                     unsigned long logic_sb_block,
 545                                     int nr)
 546 {
 547         struct ext2_sb_info *sbi = EXT2_SB(sb);
 548         unsigned long bg, first_data_block, first_meta_bg;
 549         int has_super = 0;
 550
 551         first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
 552         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 553
 554         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 555             nr < first_meta_bg)
 556                 return (logic_sb_block + nr + 1);
 557         bg = sbi->s_desc_per_block * nr;
 558         if (ext2_bg_has_super(sb, bg))
 559                 has_super = 1;
 560         return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
 561 }
 562
 563 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 564 {
 565         struct buffer_head * bh;
 566         struct ext2_sb_info * sbi;
 567         struct ext2_super_block * es;
 568         struct inode *root;
 569         unsigned long block;
 570         unsigned long sb_block = get_sb_block(&data);
 571         unsigned long logic_sb_block;
 572         unsigned long offset = 0;
 573         unsigned long def_mount_opts;
 574         int blocksize = BLOCK_SIZE;
 575         int db_count;
 576         int i, j;
 577         __le32 features;
 578
 579         sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
 580         if (!sbi)
 581                 return -ENOMEM;
 582         sb->s_fs_info = sbi;
 583         memset(sbi, 0, sizeof(*sbi));
 584
 585         /*
 586          * See what the current blocksize for the device is, and
 587          * use that as the blocksize.  Otherwise (or if the blocksize
 588          * is smaller than the default) use the default.
 589          * This is important for devices that have a hardware
 590          * sectorsize that is larger than the default.
 591          */
 592         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 593         if (!blocksize) {
 594                 printk ("EXT2-fs: unable to set blocksize\n");
 595                 goto failed_sbi;
 596         }
 597
 598         /*
 599          * If the superblock doesn't start on a hardware sector boundary,
 600          * calculate the offset.
 601          */
 602         if (blocksize != BLOCK_SIZE) {
 603                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 604                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 605         } else {
 606                 logic_sb_block = sb_block;
 607         }
 608
 609         if (!(bh = sb_bread(sb, logic_sb_block))) {
 610                 printk ("EXT2-fs: unable to read superblock\n");
 611                 goto failed_sbi;
 612         }
 613         /*
 614          * Note: s_es must be initialized as soon as possible because
 615          *       some ext2 macro-instructions depend on its value
 616          */
 617         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 618         sbi->s_es = es;
 619         sb->s_magic = le16_to_cpu(es->s_magic);
 620
 621         if (sb->s_magic != EXT2_SUPER_MAGIC)
 622                 goto cantfind_ext2;
 623
 624         /* Set defaults before we parse the mount options */
 625         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 626         if (def_mount_opts & EXT2_DEFM_DEBUG)
 627                 set_opt(sbi->s_mount_opt, DEBUG);
 628         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 629                 set_opt(sbi->s_mount_opt, GRPID);
 630         if (def_mount_opts & EXT2_DEFM_UID16)
 631                 set_opt(sbi->s_mount_opt, NO_UID32);
 632         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 633                 set_opt(sbi->s_mount_opt, XATTR_USER);
 634         if (def_mount_opts & EXT2_DEFM_ACL)
 635                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 636
 637         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 638                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 639         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
 640                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 641
 642         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 643         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 644
 645         if (!parse_options ((char *) data, sbi))
 646                 goto failed_mount;
 647
 648         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 649                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 650                  MS_POSIXACL : 0);
 651
 652         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 653                                     EXT2_MOUNT_XIP if not */
 654
 655         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 656             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 657              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 658              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 659                 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
 660                        "running e2fsck is recommended\n");
 661         /*
 662          * Check feature flags regardless of the revision level, since we
 663          * previously didn't change the revision level when setting the flags,
 664          * so there is a chance incompat flags are set on a rev 0 filesystem.
 665          */
 666         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 667         if (features) {
 668                 printk("EXT2-fs: %s: couldn't mount because of "
 669                        "unsupported optional features (%x).\n",
 670                        sb->s_id, le32_to_cpu(features));
 671                 goto failed_mount;
 672         }
 673         if (!(sb->s_flags & MS_RDONLY) &&
 674             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 675                 printk("EXT2-fs: %s: couldn't mount RDWR because of "
 676                        "unsupported optional features (%x).\n",
 677                        sb->s_id, le32_to_cpu(features));
 678                 goto failed_mount;
 679         }
 680
 681         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 682
 683         if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
 684                                   (sb->s_blocksize != blocksize))) {
 685                 if (!silent)
 686                         printk("XIP: Unsupported blocksize\n");
 687                 goto failed_mount;
 688         }
 689
 690         /* If the blocksize doesn't match, re-read the thing.. */
 691         if (sb->s_blocksize != blocksize) {
 692                 brelse(bh);
 693
 694                 if (!sb_set_blocksize(sb, blocksize)) {
 695                         printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
 696                         goto failed_sbi;
 697                 }
 698
 699                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 700                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 701                 bh = sb_bread(sb, logic_sb_block);
 702                 if(!bh) {
 703                         printk("EXT2-fs: Couldn't read superblock on "
 704                                "2nd try.\n");
 705                         goto failed_sbi;
 706                 }
 707                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 708                 sbi->s_es = es;
 709                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 710                         printk ("EXT2-fs: Magic mismatch, very weird !\n");
 711                         goto failed_mount;
 712                 }
 713         }
 714
 715         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 716
 717         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 718                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 719                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 720         } else {
 721                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 722                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 723                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 724                     (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
 725                     (sbi->s_inode_size > blocksize)) {
 726                         printk ("EXT2-fs: unsupported inode size: %d\n",
 727                                 sbi->s_inode_size);
 728                         goto failed_mount;
 729                 }
 730         }
 731
 732         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 733                                    le32_to_cpu(es->s_log_frag_size);
 734         if (sbi->s_frag_size == 0)
 735                 goto cantfind_ext2;
 736         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 737
 738         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 739         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 740         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 741
 742         if (EXT2_INODE_SIZE(sb) == 0)
 743                 goto cantfind_ext2;
 744         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 745         if (sbi->s_inodes_per_block == 0)
 746                 goto cantfind_ext2;
 747         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 748                                         sbi->s_inodes_per_block;
 749         sbi->s_desc_per_block = sb->s_blocksize /
 750                                         sizeof (struct ext2_group_desc);
 751         sbi->s_sbh = bh;
 752         sbi->s_mount_state = le16_to_cpu(es->s_state);
 753         sbi->s_addr_per_block_bits =
 754                 log2 (EXT2_ADDR_PER_BLOCK(sb));
 755         sbi->s_desc_per_block_bits =
 756                 log2 (EXT2_DESC_PER_BLOCK(sb));
 757
 758         if (sb->s_magic != EXT2_SUPER_MAGIC)
 759                 goto cantfind_ext2;
 760
 761         if (sb->s_blocksize != bh->b_size) {
 762                 if (!silent)
 763                         printk ("VFS: Unsupported blocksize on dev "
 764                                 "%s.\n", sb->s_id);
 765                 goto failed_mount;
 766         }
 767
 768         if (sb->s_blocksize != sbi->s_frag_size) {
 769                 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
 770                         sbi->s_frag_size, sb->s_blocksize);
 771                 goto failed_mount;
 772         }
 773
 774         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 775                 printk ("EXT2-fs: #blocks per group too big: %lu\n",
 776                         sbi->s_blocks_per_group);
 777                 goto failed_mount;
 778         }
 779         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 780                 printk ("EXT2-fs: #fragments per group too big: %lu\n",
 781                         sbi->s_frags_per_group);
 782                 goto failed_mount;
 783         }
 784         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 785                 printk ("EXT2-fs: #inodes per group too big: %lu\n",
 786                         sbi->s_inodes_per_group);
 787                 goto failed_mount;
 788         }
 789
 790         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 791                 goto cantfind_ext2;
 792         sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
 793                                         le32_to_cpu(es->s_first_data_block) +
 794                                        EXT2_BLOCKS_PER_GROUP(sb) - 1) /
 795                                        EXT2_BLOCKS_PER_GROUP(sb);
 796         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 797                    EXT2_DESC_PER_BLOCK(sb);
 798         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
 799         if (sbi->s_group_desc == NULL) {
 800                 printk ("EXT2-fs: not enough memory\n");
 801                 goto failed_mount;
 802         }
 803         percpu_counter_init(&sbi->s_freeblocks_counter);
 804         percpu_counter_init(&sbi->s_freeinodes_counter);
 805         percpu_counter_init(&sbi->s_dirs_counter);
 806         bgl_lock_init(&sbi->s_blockgroup_lock);
 807         sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
 808                                GFP_KERNEL);
 809         if (!sbi->s_debts) {
 810                 printk ("EXT2-fs: not enough memory\n");
 811                 goto failed_mount_group_desc;
 812         }
 813         memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
 814         for (i = 0; i < db_count; i++) {
 815                 block = descriptor_loc(sb, logic_sb_block, i);
 816                 sbi->s_group_desc[i] = sb_bread(sb, block);
 817                 if (!sbi->s_group_desc[i]) {
 818                         for (j = 0; j < i; j++)
 819                                 brelse (sbi->s_group_desc[j]);
 820                         printk ("EXT2-fs: unable to read group descriptors\n");
 821                         goto failed_mount_group_desc;
 822                 }
 823         }
 824         if (!ext2_check_descriptors (sb)) {
 825                 printk ("EXT2-fs: group descriptors corrupted!\n");
 826                 db_count = i;
 827                 goto failed_mount2;
 828         }
 829         sbi->s_gdb_count = db_count;
 830         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 831         spin_lock_init(&sbi->s_next_gen_lock);
 832         /*
 833          * set up enough so that it can read an inode
 834          */
 835         sb->s_op = &ext2_sops;
 836         sb->s_export_op = &ext2_export_ops;
 837         sb->s_xattr = ext2_xattr_handlers;
 838         root = iget(sb, EXT2_ROOT_INO);
 839         sb->s_root = d_alloc_root(root);
 840         if (!sb->s_root) {
 841                 iput(root);
 842                 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
 843                 goto failed_mount2;
 844         }
 845         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
 846                 dput(sb->s_root);
 847                 sb->s_root = NULL;
 848                 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
 849                 goto failed_mount2;
 850         }
 851         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 852                 ext2_warning(sb, __FUNCTION__,
 853                         "mounting ext3 filesystem as ext2\n");
 854         ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
 855         percpu_counter_mod(&sbi->s_freeblocks_counter,
 856                                 ext2_count_free_blocks(sb));
 857         percpu_counter_mod(&sbi->s_freeinodes_counter,
 858                                 ext2_count_free_inodes(sb));
 859         percpu_counter_mod(&sbi->s_dirs_counter,
 860                                 ext2_count_dirs(sb));
 861         return 0;
 862
 863 cantfind_ext2:
 864         if (!silent)
 865                 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
 866                        sb->s_id);
 867         goto failed_mount;
 868
 869 failed_mount2:
 870         for (i = 0; i < db_count; i++)
 871                 brelse(sbi->s_group_desc[i]);
 872 failed_mount_group_desc:
 873         kfree(sbi->s_group_desc);
 874         kfree(sbi->s_debts);
 875 failed_mount:
 876         brelse(bh);
 877 failed_sbi:
 878         sb->s_fs_info = NULL;
 879         kfree(sbi);
 880         return -EINVAL;
 881 }
 882
 883 static void ext2_commit_super (struct super_block * sb,
 884                                struct ext2_super_block * es)
 885 {
 886         es->s_wtime = cpu_to_le32(get_seconds());
 887         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
 888         sb->s_dirt = 0;
 889 }
 890
 891 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
 892 {
 893         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
 894         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
 895         es->s_wtime = cpu_to_le32(get_seconds());
 896         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
 897         sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
 898         sb->s_dirt = 0;
 899 }
 900
 901 /*
 902  * In the second extended file system, it is not necessary to
 903  * write the super block since we use a mapping of the
 904  * disk super block in a buffer.
 905  *
 906  * However, this function is still used to set the fs valid
 907  * flags to 0.  We need to set this flag to 0 since the fs
 908  * may have been checked while mounted and e2fsck may have
 909  * set s_state to EXT2_VALID_FS after some corrections.
 910  */
 911
 912 void ext2_write_super (struct super_block * sb)
 913 {
 914         struct ext2_super_block * es;
 915         lock_kernel();
 916         if (!(sb->s_flags & MS_RDONLY)) {
 917                 es = EXT2_SB(sb)->s_es;
 918
 919                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
 920                         ext2_debug ("setting valid to 0\n");
 921                         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
 922                                                   ~EXT2_VALID_FS);
 923                         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
 924                         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
 925                         es->s_mtime = cpu_to_le32(get_seconds());
 926                         ext2_sync_super(sb, es);
 927                 } else
 928                         ext2_commit_super (sb, es);
 929         }
 930         sb->s_dirt = 0;
 931         unlock_kernel();
 932 }
 933
 934 static int ext2_remount (struct super_block * sb, int * flags, char * data)
 935 {
 936         struct ext2_sb_info * sbi = EXT2_SB(sb);
 937         struct ext2_super_block * es;
 938         unsigned long old_mount_opt = sbi->s_mount_opt;
 939         struct ext2_mount_options old_opts;
 940         unsigned long old_sb_flags;
 941         int err;
 942
 943         /* Store the old options */
 944         old_sb_flags = sb->s_flags;
 945         old_opts.s_mount_opt = sbi->s_mount_opt;
 946         old_opts.s_resuid = sbi->s_resuid;
 947         old_opts.s_resgid = sbi->s_resgid;
 948
 949         /*
 950          * Allow the "check" option to be passed as a remount option.
 951          */
 952         if (!parse_options (data, sbi)) {
 953                 err = -EINVAL;
 954                 goto restore_opts;
 955         }
 956
 957         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 958                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
 959
 960         es = sbi->s_es;
 961         if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
 962             (old_mount_opt & EXT2_MOUNT_XIP)) &&
 963             invalidate_inodes(sb))
 964                 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
 965                              "xip remain in cache (no functional problem)");
 966         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 967                 return 0;
 968         if (*flags & MS_RDONLY) {
 969                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
 970                     !(sbi->s_mount_state & EXT2_VALID_FS))
 971                         return 0;
 972                 /*
 973                  * OK, we are remounting a valid rw partition rdonly, so set
 974                  * the rdonly flag and then mark the partition as valid again.
 975                  */
 976                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 977                 es->s_mtime = cpu_to_le32(get_seconds());
 978         } else {
 979                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
 980                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
 981                 if (ret) {
 982                         printk("EXT2-fs: %s: couldn't remount RDWR because of "
 983                                "unsupported optional features (%x).\n",
 984                                sb->s_id, le32_to_cpu(ret));
 985                         err = -EROFS;
 986                         goto restore_opts;
 987                 }
 988                 /*
 989                  * Mounting a RDONLY partition read-write, so reread and
 990                  * store the current valid flag.  (It may have been changed
 991                  * by e2fsck since we originally mounted the partition.)
 992                  */
 993                 sbi->s_mount_state = le16_to_cpu(es->s_state);
 994                 if (!ext2_setup_super (sb, es, 0))
 995                         sb->s_flags &= ~MS_RDONLY;
 996         }
 997         ext2_sync_super(sb, es);
 998         return 0;
 999 restore_opts:
1000         sbi->s_mount_opt = old_opts.s_mount_opt;
1001         sbi->s_resuid = old_opts.s_resuid;
1002         sbi->s_resgid = old_opts.s_resgid;
1003         sb->s_flags = old_sb_flags;
1004         return err;
1005 }
1006
1007 static int ext2_statfs (struct super_block * sb, struct kstatfs * buf)
1008 {
1009         struct ext2_sb_info *sbi = EXT2_SB(sb);
1010         unsigned long overhead;
1011         int i;
1012
1013         if (test_opt (sb, MINIX_DF))
1014                 overhead = 0;
1015         else {
1016                 /*
1017                  * Compute the overhead (FS structures)
1018                  */
1019
1020                 /*
1021                  * All of the blocks before first_data_block are
1022                  * overhead
1023                  */
1024                 overhead = le32_to_cpu(sbi->s_es->s_first_data_block);
1025
1026                 /*
1027                  * Add the overhead attributed to the superblock and
1028                  * block group descriptors.  If the sparse superblocks
1029                  * feature is turned on, then not all groups have this.
1030                  */
1031                 for (i = 0; i < sbi->s_groups_count; i++)
1032                         overhead += ext2_bg_has_super(sb, i) +
1033                                 ext2_bg_num_gdb(sb, i);
1034
1035                 /*
1036                  * Every block group has an inode bitmap, a block
1037                  * bitmap, and an inode table.
1038                  */
1039                 overhead += (sbi->s_groups_count *
1040                              (2 + sbi->s_itb_per_group));
1041         }
1042
1043         buf->f_type = EXT2_SUPER_MAGIC;
1044         buf->f_bsize = sb->s_blocksize;
1045         buf->f_blocks = le32_to_cpu(sbi->s_es->s_blocks_count) - overhead;
1046         buf->f_bfree = ext2_count_free_blocks(sb);
1047         buf->f_bavail = buf->f_bfree - le32_to_cpu(sbi->s_es->s_r_blocks_count);
1048         if (buf->f_bfree < le32_to_cpu(sbi->s_es->s_r_blocks_count))
1049                 buf->f_bavail = 0;
1050         buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count);
1051         buf->f_ffree = ext2_count_free_inodes (sb);
1052         buf->f_namelen = EXT2_NAME_LEN;
1053         return 0;
1054 }
1055
1056 static struct super_block *ext2_get_sb(struct file_system_type *fs_type,
1057         int flags, const char *dev_name, void *data)
1058 {
1059         return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1060 }
1061
1062 #ifdef CONFIG_QUOTA
1063
1064 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1065  * acquiring the locks... As quota files are never truncated and quota code
1066  * itself serializes the operations (and noone else should touch the files)
1067  * we don't have to be afraid of races */
1068 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1069                                size_t len, loff_t off)
1070 {
1071         struct inode *inode = sb_dqopt(sb)->files[type];
1072         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1073         int err = 0;
1074         int offset = off & (sb->s_blocksize - 1);
1075         int tocopy;
1076         size_t toread;
1077         struct buffer_head tmp_bh;
1078         struct buffer_head *bh;
1079         loff_t i_size = i_size_read(inode);
1080
1081         if (off > i_size)
1082                 return 0;
1083         if (off+len > i_size)
1084                 len = i_size-off;
1085         toread = len;
1086         while (toread > 0) {
1087                 tocopy = sb->s_blocksize - offset < toread ?
1088                                 sb->s_blocksize - offset : toread;
1089
1090                 tmp_bh.b_state = 0;
1091                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1092                 if (err)
1093                         return err;
1094                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1095                         memset(data, 0, tocopy);
1096                 else {
1097                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1098                         if (!bh)
1099                                 return -EIO;
1100                         memcpy(data, bh->b_data+offset, tocopy);
1101                         brelse(bh);
1102                 }
1103                 offset = 0;
1104                 toread -= tocopy;
1105                 data += tocopy;
1106                 blk++;
1107         }
1108         return len;
1109 }
1110
1111 /* Write to quotafile */
1112 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1113                                 const char *data, size_t len, loff_t off)
1114 {
1115         struct inode *inode = sb_dqopt(sb)->files[type];
1116         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1117         int err = 0;
1118         int offset = off & (sb->s_blocksize - 1);
1119         int tocopy;
1120         size_t towrite = len;
1121         struct buffer_head tmp_bh;
1122         struct buffer_head *bh;
1123
1124         down(&inode->i_sem);
1125         while (towrite > 0) {
1126                 tocopy = sb->s_blocksize - offset < towrite ?
1127                                 sb->s_blocksize - offset : towrite;
1128
1129                 tmp_bh.b_state = 0;
1130                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1131                 if (err)
1132                         goto out;
1133                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1134                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1135                 else
1136                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1137                 if (!bh) {
1138                         err = -EIO;
1139                         goto out;
1140                 }
1141                 lock_buffer(bh);
1142                 memcpy(bh->b_data+offset, data, tocopy);
1143                 flush_dcache_page(bh->b_page);
1144                 set_buffer_uptodate(bh);
1145                 mark_buffer_dirty(bh);
1146                 unlock_buffer(bh);
1147                 brelse(bh);
1148                 offset = 0;
1149                 towrite -= tocopy;
1150                 data += tocopy;
1151                 blk++;
1152         }
1153 out:
1154         if (len == towrite)
1155                 return err;
1156         if (inode->i_size < off+len-towrite)
1157                 i_size_write(inode, off+len-towrite);
1158         inode->i_version++;
1159         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1160         mark_inode_dirty(inode);
1161         up(&inode->i_sem);
1162         return len - towrite;
1163 }
1164
1165 #endif
1166
1167 static struct file_system_type ext2_fs_type = {
1168         .owner          = THIS_MODULE,
1169         .name           = "ext2",
1170         .get_sb         = ext2_get_sb,
1171         .kill_sb        = kill_block_super,
1172         .fs_flags       = FS_REQUIRES_DEV,
1173 };
1174
1175 static int __init init_ext2_fs(void)
1176 {
1177         int err = init_ext2_xattr();
1178         if (err)
1179                 return err;
1180         err = init_inodecache();
1181         if (err)
1182                 goto out1;
1183         err = register_filesystem(&ext2_fs_type);
1184         if (err)
1185                 goto out;
1186         return 0;
1187 out:
1188         destroy_inodecache();
1189 out1:
1190         exit_ext2_xattr();
1191         return err;
1192 }
1193
1194 static void __exit exit_ext2_fs(void)
1195 {
1196         unregister_filesystem(&ext2_fs_type);
1197         destroy_inodecache();
1198         exit_ext2_xattr();
1199 }
1200
1201 module_init(init_ext2_fs)
1202 module_exit(exit_ext2_fs)