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/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.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 <linux/seq_file.h>
  31 #include <linux/mount.h>
  32 #include <asm/uaccess.h>
  33 #include "ext2.h"
  34 #include "xattr.h"
  35 #include "acl.h"
  36 #include "xip.h"
  37
  38 static void ext2_sync_super(struct super_block *sb,
  39                             struct ext2_super_block *es);
  40 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  41 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  42
  43 void ext2_error (struct super_block * sb, const char * function,
  44                  const char * fmt, ...)
  45 {
  46         va_list args;
  47         struct ext2_sb_info *sbi = EXT2_SB(sb);
  48         struct ext2_super_block *es = sbi->s_es;
  49
  50         if (!(sb->s_flags & MS_RDONLY)) {
  51                 sbi->s_mount_state |= EXT2_ERROR_FS;
  52                 es->s_state =
  53                         cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
  54                 ext2_sync_super(sb, es);
  55         }
  56
  57         va_start(args, fmt);
  58         printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
  59         vprintk(fmt, args);
  60         printk("\n");
  61         va_end(args);
  62
  63         if (test_opt(sb, ERRORS_PANIC))
  64                 panic("EXT2-fs panic from previous error\n");
  65         if (test_opt(sb, ERRORS_RO)) {
  66                 printk("Remounting filesystem read-only\n");
  67                 sb->s_flags |= MS_RDONLY;
  68         }
  69 }
  70
  71 void ext2_warning (struct super_block * sb, const char * function,
  72                    const char * fmt, ...)
  73 {
  74         va_list args;
  75
  76         va_start(args, fmt);
  77         printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
  78                sb->s_id, function);
  79         vprintk(fmt, args);
  80         printk("\n");
  81         va_end(args);
  82 }
  83
  84 void ext2_update_dynamic_rev(struct super_block *sb)
  85 {
  86         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
  87
  88         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
  89                 return;
  90
  91         ext2_warning(sb, __FUNCTION__,
  92                      "updating to rev %d because of new feature flag, "
  93                      "running e2fsck is recommended",
  94                      EXT2_DYNAMIC_REV);
  95
  96         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
  97         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
  98         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
  99         /* leave es->s_feature_*compat flags alone */
 100         /* es->s_uuid will be set by e2fsck if empty */
 101
 102         /*
 103          * The rest of the superblock fields should be zero, and if not it
 104          * means they are likely already in use, so leave them alone.  We
 105          * can leave it up to e2fsck to clean up any inconsistencies there.
 106          */
 107 }
 108
 109 static void ext2_put_super (struct super_block * sb)
 110 {
 111         int db_count;
 112         int i;
 113         struct ext2_sb_info *sbi = EXT2_SB(sb);
 114
 115         ext2_xattr_put_super(sb);
 116         if (!(sb->s_flags & MS_RDONLY)) {
 117                 struct ext2_super_block *es = sbi->s_es;
 118
 119                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 120                 ext2_sync_super(sb, es);
 121         }
 122         db_count = sbi->s_gdb_count;
 123         for (i = 0; i < db_count; i++)
 124                 if (sbi->s_group_desc[i])
 125                         brelse (sbi->s_group_desc[i]);
 126         kfree(sbi->s_group_desc);
 127         kfree(sbi->s_debts);
 128         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 129         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 130         percpu_counter_destroy(&sbi->s_dirs_counter);
 131         brelse (sbi->s_sbh);
 132         sb->s_fs_info = NULL;
 133         kfree(sbi);
 134
 135         return;
 136 }
 137
 138 static struct kmem_cache * ext2_inode_cachep;
 139
 140 static struct inode *ext2_alloc_inode(struct super_block *sb)
 141 {
 142         struct ext2_inode_info *ei;
 143         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 144         if (!ei)
 145                 return NULL;
 146 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 147         ei->i_acl = EXT2_ACL_NOT_CACHED;
 148         ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 149 #endif
 150         ei->vfs_inode.i_version = 1;
 151         return &ei->vfs_inode;
 152 }
 153
 154 static void ext2_destroy_inode(struct inode *inode)
 155 {
 156         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 157 }
 158
 159 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
 160 {
 161         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 162
 163         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 164             SLAB_CTOR_CONSTRUCTOR) {
 165                 rwlock_init(&ei->i_meta_lock);
 166 #ifdef CONFIG_EXT2_FS_XATTR
 167                 init_rwsem(&ei->xattr_sem);
 168 #endif
 169                 inode_init_once(&ei->vfs_inode);
 170         }
 171 }
 172
 173 static int init_inodecache(void)
 174 {
 175         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 176                                              sizeof(struct ext2_inode_info),
 177                                              0, (SLAB_RECLAIM_ACCOUNT|
 178                                                 SLAB_MEM_SPREAD),
 179                                              init_once, NULL);
 180         if (ext2_inode_cachep == NULL)
 181                 return -ENOMEM;
 182         return 0;
 183 }
 184
 185 static void destroy_inodecache(void)
 186 {
 187         kmem_cache_destroy(ext2_inode_cachep);
 188 }
 189
 190 static void ext2_clear_inode(struct inode *inode)
 191 {
 192 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 193         struct ext2_inode_info *ei = EXT2_I(inode);
 194
 195         if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
 196                 posix_acl_release(ei->i_acl);
 197                 ei->i_acl = EXT2_ACL_NOT_CACHED;
 198         }
 199         if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
 200                 posix_acl_release(ei->i_default_acl);
 201                 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 202         }
 203 #endif
 204 }
 205
 206 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
 207 {
 208         struct ext2_sb_info *sbi = EXT2_SB(vfs->mnt_sb);
 209
 210         if (sbi->s_mount_opt & EXT2_MOUNT_GRPID)
 211                 seq_puts(seq, ",grpid");
 212
 213 #if defined(CONFIG_QUOTA)
 214         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 215                 seq_puts(seq, ",usrquota");
 216
 217         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 218                 seq_puts(seq, ",grpquota");
 219 #endif
 220
 221 #if defined(CONFIG_EXT2_FS_XIP)
 222         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 223                 seq_puts(seq, ",xip");
 224 #endif
 225
 226         return 0;
 227 }
 228
 229 #ifdef CONFIG_QUOTA
 230 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 231 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 232 #endif
 233
 234 static struct super_operations ext2_sops = {
 235         .alloc_inode    = ext2_alloc_inode,
 236         .destroy_inode  = ext2_destroy_inode,
 237         .read_inode     = ext2_read_inode,
 238         .write_inode    = ext2_write_inode,
 239         .put_inode      = ext2_put_inode,
 240         .delete_inode   = ext2_delete_inode,
 241         .put_super      = ext2_put_super,
 242         .write_super    = ext2_write_super,
 243         .statfs         = ext2_statfs,
 244         .remount_fs     = ext2_remount,
 245         .clear_inode    = ext2_clear_inode,
 246         .show_options   = ext2_show_options,
 247 #ifdef CONFIG_QUOTA
 248         .quota_read     = ext2_quota_read,
 249         .quota_write    = ext2_quota_write,
 250 #endif
 251 };
 252
 253 static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
 254 {
 255         __u32 *objp = vobjp;
 256         unsigned long ino = objp[0];
 257         __u32 generation = objp[1];
 258         struct inode *inode;
 259         struct dentry *result;
 260
 261         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 262                 return ERR_PTR(-ESTALE);
 263         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 264                 return ERR_PTR(-ESTALE);
 265
 266         /* iget isn't really right if the inode is currently unallocated!!
 267          * ext2_read_inode currently does appropriate checks, but
 268          * it might be "neater" to call ext2_get_inode first and check
 269          * if the inode is valid.....
 270          */
 271         inode = iget(sb, ino);
 272         if (inode == NULL)
 273                 return ERR_PTR(-ENOMEM);
 274         if (is_bad_inode(inode) ||
 275             (generation && inode->i_generation != generation)) {
 276                 /* we didn't find the right inode.. */
 277                 iput(inode);
 278                 return ERR_PTR(-ESTALE);
 279         }
 280         /* now to find a dentry.
 281          * If possible, get a well-connected one
 282          */
 283         result = d_alloc_anon(inode);
 284         if (!result) {
 285                 iput(inode);
 286                 return ERR_PTR(-ENOMEM);
 287         }
 288         return result;
 289 }
 290
 291 /* Yes, most of these are left as NULL!!
 292  * A NULL value implies the default, which works with ext2-like file
 293  * systems, but can be improved upon.
 294  * Currently only get_parent is required.
 295  */
 296 static struct export_operations ext2_export_ops = {
 297         .get_parent = ext2_get_parent,
 298         .get_dentry = ext2_get_dentry,
 299 };
 300
 301 static unsigned long get_sb_block(void **data)
 302 {
 303         unsigned long   sb_block;
 304         char            *options = (char *) *data;
 305
 306         if (!options || strncmp(options, "sb=", 3) != 0)
 307                 return 1;       /* Default location */
 308         options += 3;
 309         sb_block = simple_strtoul(options, &options, 0);
 310         if (*options && *options != ',') {
 311                 printk("EXT2-fs: Invalid sb specification: %s\n",
 312                        (char *) *data);
 313                 return 1;
 314         }
 315         if (*options == ',')
 316                 options++;
 317         *data = (void *) options;
 318         return sb_block;
 319 }
 320
 321 enum {
 322         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 323         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 324         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 325         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 326         Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 327         Opt_usrquota, Opt_grpquota, Opt_tag, Opt_notag, Opt_tagid
 328 };
 329
 330 static match_table_t tokens = {
 331         {Opt_bsd_df, "bsddf"},
 332         {Opt_minix_df, "minixdf"},
 333         {Opt_grpid, "grpid"},
 334         {Opt_grpid, "bsdgroups"},
 335         {Opt_nogrpid, "nogrpid"},
 336         {Opt_nogrpid, "sysvgroups"},
 337         {Opt_resgid, "resgid=%u"},
 338         {Opt_resuid, "resuid=%u"},
 339         {Opt_sb, "sb=%u"},
 340         {Opt_err_cont, "errors=continue"},
 341         {Opt_err_panic, "errors=panic"},
 342         {Opt_err_ro, "errors=remount-ro"},
 343         {Opt_nouid32, "nouid32"},
 344         {Opt_nocheck, "check=none"},
 345         {Opt_nocheck, "nocheck"},
 346         {Opt_debug, "debug"},
 347         {Opt_oldalloc, "oldalloc"},
 348         {Opt_orlov, "orlov"},
 349         {Opt_nobh, "nobh"},
 350         {Opt_user_xattr, "user_xattr"},
 351         {Opt_nouser_xattr, "nouser_xattr"},
 352         {Opt_acl, "acl"},
 353         {Opt_noacl, "noacl"},
 354         {Opt_xip, "xip"},
 355         {Opt_tag, "tag"},
 356         {Opt_notag, "notag"},
 357         {Opt_tagid, "tagid=%u"},
 358         {Opt_tag, "tagxid"},
 359         {Opt_grpquota, "grpquota"},
 360         {Opt_ignore, "noquota"},
 361         {Opt_quota, "quota"},
 362         {Opt_usrquota, "usrquota"},
 363         {Opt_err, NULL}
 364 };
 365
 366 static int parse_options (char * options,
 367                           struct ext2_sb_info *sbi)
 368 {
 369         char * p;
 370         substring_t args[MAX_OPT_ARGS];
 371         int option;
 372
 373         if (!options)
 374                 return 1;
 375
 376         while ((p = strsep (&options, ",")) != NULL) {
 377                 int token;
 378                 if (!*p)
 379                         continue;
 380
 381                 token = match_token(p, tokens, args);
 382                 switch (token) {
 383                 case Opt_bsd_df:
 384                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 385                         break;
 386                 case Opt_minix_df:
 387                         set_opt (sbi->s_mount_opt, MINIX_DF);
 388                         break;
 389                 case Opt_grpid:
 390                         set_opt (sbi->s_mount_opt, GRPID);
 391                         break;
 392                 case Opt_nogrpid:
 393                         clear_opt (sbi->s_mount_opt, GRPID);
 394                         break;
 395                 case Opt_resuid:
 396                         if (match_int(&args[0], &option))
 397                                 return 0;
 398                         sbi->s_resuid = option;
 399                         break;
 400                 case Opt_resgid:
 401                         if (match_int(&args[0], &option))
 402                                 return 0;
 403                         sbi->s_resgid = option;
 404                         break;
 405                 case Opt_sb:
 406                         /* handled by get_sb_block() instead of here */
 407                         /* *sb_block = match_int(&args[0]); */
 408                         break;
 409                 case Opt_err_panic:
 410                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 411                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 412                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 413                         break;
 414                 case Opt_err_ro:
 415                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 416                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 417                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 418                         break;
 419                 case Opt_err_cont:
 420                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 421                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 422                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 423                         break;
 424                 case Opt_nouid32:
 425                         set_opt (sbi->s_mount_opt, NO_UID32);
 426                         break;
 427 #ifndef CONFIG_TAGGING_NONE
 428                 case Opt_tag:
 429                         set_opt (sbi->s_mount_opt, TAGGED);
 430                         break;
 431                 case Opt_notag:
 432                         clear_opt (sbi->s_mount_opt, TAGGED);
 433                         break;
 434 #endif
 435 #ifdef CONFIG_PROPAGATE
 436                 case Opt_tagid:
 437                         /* use args[0] */
 438                         set_opt (sbi->s_mount_opt, TAGGED);
 439                         break;
 440 #endif
 441                 case Opt_nocheck:
 442                         clear_opt (sbi->s_mount_opt, CHECK);
 443                         break;
 444                 case Opt_debug:
 445                         set_opt (sbi->s_mount_opt, DEBUG);
 446                         break;
 447                 case Opt_oldalloc:
 448                         set_opt (sbi->s_mount_opt, OLDALLOC);
 449                         break;
 450                 case Opt_orlov:
 451                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 452                         break;
 453                 case Opt_nobh:
 454                         set_opt (sbi->s_mount_opt, NOBH);
 455                         break;
 456 #ifdef CONFIG_EXT2_FS_XATTR
 457                 case Opt_user_xattr:
 458                         set_opt (sbi->s_mount_opt, XATTR_USER);
 459                         break;
 460                 case Opt_nouser_xattr:
 461                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 462                         break;
 463 #else
 464                 case Opt_user_xattr:
 465                 case Opt_nouser_xattr:
 466                         printk("EXT2 (no)user_xattr options not supported\n");
 467                         break;
 468 #endif
 469 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 470                 case Opt_acl:
 471                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 472                         break;
 473                 case Opt_noacl:
 474                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 475                         break;
 476 #else
 477                 case Opt_acl:
 478                 case Opt_noacl:
 479                         printk("EXT2 (no)acl options not supported\n");
 480                         break;
 481 #endif
 482                 case Opt_xip:
 483 #ifdef CONFIG_EXT2_FS_XIP
 484                         set_opt (sbi->s_mount_opt, XIP);
 485 #else
 486                         printk("EXT2 xip option not supported\n");
 487 #endif
 488                         break;
 489
 490 #if defined(CONFIG_QUOTA)
 491                 case Opt_quota:
 492                 case Opt_usrquota:
 493                         set_opt(sbi->s_mount_opt, USRQUOTA);
 494                         break;
 495
 496                 case Opt_grpquota:
 497                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 498                         break;
 499 #else
 500                 case Opt_quota:
 501                 case Opt_usrquota:
 502                 case Opt_grpquota:
 503                         printk(KERN_ERR
 504                                 "EXT2-fs: quota operations not supported.\n");
 505
 506                         break;
 507 #endif
 508
 509                 case Opt_ignore:
 510                         break;
 511                 default:
 512                         return 0;
 513                 }
 514         }
 515         return 1;
 516 }
 517
 518 static int ext2_setup_super (struct super_block * sb,
 519                               struct ext2_super_block * es,
 520                               int read_only)
 521 {
 522         int res = 0;
 523         struct ext2_sb_info *sbi = EXT2_SB(sb);
 524
 525         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 526                 printk ("EXT2-fs warning: revision level too high, "
 527                         "forcing read-only mode\n");
 528                 res = MS_RDONLY;
 529         }
 530         if (read_only)
 531                 return res;
 532         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 533                 printk ("EXT2-fs warning: mounting unchecked fs, "
 534                         "running e2fsck is recommended\n");
 535         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 536                 printk ("EXT2-fs warning: mounting fs with errors, "
 537                         "running e2fsck is recommended\n");
 538         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 539                  le16_to_cpu(es->s_mnt_count) >=
 540                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 541                 printk ("EXT2-fs warning: maximal mount count reached, "
 542                         "running e2fsck is recommended\n");
 543         else if (le32_to_cpu(es->s_checkinterval) &&
 544                 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 545                 printk ("EXT2-fs warning: checktime reached, "
 546                         "running e2fsck is recommended\n");
 547         if (!le16_to_cpu(es->s_max_mnt_count))
 548                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 549         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
 550         ext2_write_super(sb);
 551         if (test_opt (sb, DEBUG))
 552                 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
 553                         "bpg=%lu, ipg=%lu, mo=%04lx]\n",
 554                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 555                         sbi->s_frag_size,
 556                         sbi->s_groups_count,
 557                         EXT2_BLOCKS_PER_GROUP(sb),
 558                         EXT2_INODES_PER_GROUP(sb),
 559                         sbi->s_mount_opt);
 560         return res;
 561 }
 562
 563 static int ext2_check_descriptors (struct super_block * sb)
 564 {
 565         int i;
 566         int desc_block = 0;
 567         struct ext2_sb_info *sbi = EXT2_SB(sb);
 568         unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
 569         unsigned long last_block;
 570         struct ext2_group_desc * gdp = NULL;
 571
 572         ext2_debug ("Checking group descriptors");
 573
 574         for (i = 0; i < sbi->s_groups_count; i++)
 575         {
 576                 if (i == sbi->s_groups_count - 1)
 577                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 578                 else
 579                         last_block = first_block +
 580                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 581
 582                 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
 583                         gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
 584                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 585                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 586                 {
 587                         ext2_error (sb, "ext2_check_descriptors",
 588                                     "Block bitmap for group %d"
 589                                     " not in group (block %lu)!",
 590                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 591                         return 0;
 592                 }
 593                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 594                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 595                 {
 596                         ext2_error (sb, "ext2_check_descriptors",
 597                                     "Inode bitmap for group %d"
 598                                     " not in group (block %lu)!",
 599                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 600                         return 0;
 601                 }
 602                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 603                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >
 604                     last_block)
 605                 {
 606                         ext2_error (sb, "ext2_check_descriptors",
 607                                     "Inode table for group %d"
 608                                     " not in group (block %lu)!",
 609                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 610                         return 0;
 611                 }
 612                 first_block += EXT2_BLOCKS_PER_GROUP(sb);
 613                 gdp++;
 614         }
 615         return 1;
 616 }
 617
 618 /*
 619  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 620  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 621  * We need to be 1 filesystem block less than the 2^32 sector limit.
 622  */
 623 static loff_t ext2_max_size(int bits)
 624 {
 625         loff_t res = EXT2_NDIR_BLOCKS;
 626         /* This constant is calculated to be the largest file size for a
 627          * dense, 4k-blocksize file such that the total number of
 628          * sectors in the file, including data and all indirect blocks,
 629          * does not exceed 2^32. */
 630         const loff_t upper_limit = 0x1ff7fffd000LL;
 631
 632         res += 1LL << (bits-2);
 633         res += 1LL << (2*(bits-2));
 634         res += 1LL << (3*(bits-2));
 635         res <<= bits;
 636         if (res > upper_limit)
 637                 res = upper_limit;
 638         return res;
 639 }
 640
 641 static unsigned long descriptor_loc(struct super_block *sb,
 642                                     unsigned long logic_sb_block,
 643                                     int nr)
 644 {
 645         struct ext2_sb_info *sbi = EXT2_SB(sb);
 646         unsigned long bg, first_data_block, first_meta_bg;
 647         int has_super = 0;
 648
 649         first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
 650         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 651
 652         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 653             nr < first_meta_bg)
 654                 return (logic_sb_block + nr + 1);
 655         bg = sbi->s_desc_per_block * nr;
 656         if (ext2_bg_has_super(sb, bg))
 657                 has_super = 1;
 658         return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
 659 }
 660
 661 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 662 {
 663         struct buffer_head * bh;
 664         struct ext2_sb_info * sbi;
 665         struct ext2_super_block * es;
 666         struct inode *root;
 667         unsigned long block;
 668         unsigned long sb_block = get_sb_block(&data);
 669         unsigned long logic_sb_block;
 670         unsigned long offset = 0;
 671         unsigned long def_mount_opts;
 672         int blocksize = BLOCK_SIZE;
 673         int db_count;
 674         int i, j;
 675         __le32 features;
 676
 677         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 678         if (!sbi)
 679                 return -ENOMEM;
 680         sb->s_fs_info = sbi;
 681
 682         /*
 683          * See what the current blocksize for the device is, and
 684          * use that as the blocksize.  Otherwise (or if the blocksize
 685          * is smaller than the default) use the default.
 686          * This is important for devices that have a hardware
 687          * sectorsize that is larger than the default.
 688          */
 689         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 690         if (!blocksize) {
 691                 printk ("EXT2-fs: unable to set blocksize\n");
 692                 goto failed_sbi;
 693         }
 694
 695         /*
 696          * If the superblock doesn't start on a hardware sector boundary,
 697          * calculate the offset.
 698          */
 699         if (blocksize != BLOCK_SIZE) {
 700                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 701                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 702         } else {
 703                 logic_sb_block = sb_block;
 704         }
 705
 706         if (!(bh = sb_bread(sb, logic_sb_block))) {
 707                 printk ("EXT2-fs: unable to read superblock\n");
 708                 goto failed_sbi;
 709         }
 710         /*
 711          * Note: s_es must be initialized as soon as possible because
 712          *       some ext2 macro-instructions depend on its value
 713          */
 714         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 715         sbi->s_es = es;
 716         sb->s_magic = le16_to_cpu(es->s_magic);
 717
 718         if (sb->s_magic != EXT2_SUPER_MAGIC)
 719                 goto cantfind_ext2;
 720
 721         /* Set defaults before we parse the mount options */
 722         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 723         if (def_mount_opts & EXT2_DEFM_DEBUG)
 724                 set_opt(sbi->s_mount_opt, DEBUG);
 725         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 726                 set_opt(sbi->s_mount_opt, GRPID);
 727         if (def_mount_opts & EXT2_DEFM_UID16)
 728                 set_opt(sbi->s_mount_opt, NO_UID32);
 729 #ifdef CONFIG_EXT2_FS_XATTR
 730         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 731                 set_opt(sbi->s_mount_opt, XATTR_USER);
 732 #endif
 733 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 734         if (def_mount_opts & EXT2_DEFM_ACL)
 735                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 736 #endif
 737
 738         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 739                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 740         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
 741                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 742         else
 743                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 744
 745         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 746         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 747
 748         if (!parse_options ((char *) data, sbi))
 749                 goto failed_mount;
 750
 751         if (EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_TAGGED)
 752                 sb->s_flags |= MS_TAGGED;
 753         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 754                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 755                  MS_POSIXACL : 0);
 756
 757         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 758                                     EXT2_MOUNT_XIP if not */
 759
 760         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 761             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 762              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 763              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 764                 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
 765                        "running e2fsck is recommended\n");
 766         /*
 767          * Check feature flags regardless of the revision level, since we
 768          * previously didn't change the revision level when setting the flags,
 769          * so there is a chance incompat flags are set on a rev 0 filesystem.
 770          */
 771         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 772         if (features) {
 773                 printk("EXT2-fs: %s: couldn't mount because of "
 774                        "unsupported optional features (%x).\n",
 775                        sb->s_id, le32_to_cpu(features));
 776                 goto failed_mount;
 777         }
 778         if (!(sb->s_flags & MS_RDONLY) &&
 779             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 780                 printk("EXT2-fs: %s: couldn't mount RDWR because of "
 781                        "unsupported optional features (%x).\n",
 782                        sb->s_id, le32_to_cpu(features));
 783                 goto failed_mount;
 784         }
 785
 786         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 787
 788         if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
 789                                   (sb->s_blocksize != blocksize))) {
 790                 if (!silent)
 791                         printk("XIP: Unsupported blocksize\n");
 792                 goto failed_mount;
 793         }
 794
 795         /* If the blocksize doesn't match, re-read the thing.. */
 796         if (sb->s_blocksize != blocksize) {
 797                 brelse(bh);
 798
 799                 if (!sb_set_blocksize(sb, blocksize)) {
 800                         printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
 801                         goto failed_sbi;
 802                 }
 803
 804                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 805                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 806                 bh = sb_bread(sb, logic_sb_block);
 807                 if(!bh) {
 808                         printk("EXT2-fs: Couldn't read superblock on "
 809                                "2nd try.\n");
 810                         goto failed_sbi;
 811                 }
 812                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 813                 sbi->s_es = es;
 814                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 815                         printk ("EXT2-fs: Magic mismatch, very weird !\n");
 816                         goto failed_mount;
 817                 }
 818         }
 819
 820         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 821
 822         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 823                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 824                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 825         } else {
 826                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 827                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 828                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 829                     (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
 830                     (sbi->s_inode_size > blocksize)) {
 831                         printk ("EXT2-fs: unsupported inode size: %d\n",
 832                                 sbi->s_inode_size);
 833                         goto failed_mount;
 834                 }
 835         }
 836
 837         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 838                                    le32_to_cpu(es->s_log_frag_size);
 839         if (sbi->s_frag_size == 0)
 840                 goto cantfind_ext2;
 841         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 842
 843         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 844         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 845         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 846
 847         if (EXT2_INODE_SIZE(sb) == 0)
 848                 goto cantfind_ext2;
 849         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 850         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 851                 goto cantfind_ext2;
 852         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 853                                         sbi->s_inodes_per_block;
 854         sbi->s_desc_per_block = sb->s_blocksize /
 855                                         sizeof (struct ext2_group_desc);
 856         sbi->s_sbh = bh;
 857         sbi->s_mount_state = le16_to_cpu(es->s_state);
 858         sbi->s_addr_per_block_bits =
 859                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 860         sbi->s_desc_per_block_bits =
 861                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
 862
 863         if (sb->s_magic != EXT2_SUPER_MAGIC)
 864                 goto cantfind_ext2;
 865
 866         if (sb->s_blocksize != bh->b_size) {
 867                 if (!silent)
 868                         printk ("VFS: Unsupported blocksize on dev "
 869                                 "%s.\n", sb->s_id);
 870                 goto failed_mount;
 871         }
 872
 873         if (sb->s_blocksize != sbi->s_frag_size) {
 874                 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
 875                         sbi->s_frag_size, sb->s_blocksize);
 876                 goto failed_mount;
 877         }
 878
 879         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 880                 printk ("EXT2-fs: #blocks per group too big: %lu\n",
 881                         sbi->s_blocks_per_group);
 882                 goto failed_mount;
 883         }
 884         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 885                 printk ("EXT2-fs: #fragments per group too big: %lu\n",
 886                         sbi->s_frags_per_group);
 887                 goto failed_mount;
 888         }
 889         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 890                 printk ("EXT2-fs: #inodes per group too big: %lu\n",
 891                         sbi->s_inodes_per_group);
 892                 goto failed_mount;
 893         }
 894
 895         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 896                 goto cantfind_ext2;
 897         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
 898                                 le32_to_cpu(es->s_first_data_block) - 1)
 899                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
 900         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 901                    EXT2_DESC_PER_BLOCK(sb);
 902         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
 903         if (sbi->s_group_desc == NULL) {
 904                 printk ("EXT2-fs: not enough memory\n");
 905                 goto failed_mount;
 906         }
 907         bgl_lock_init(&sbi->s_blockgroup_lock);
 908         sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(*sbi->s_debts),
 909                                GFP_KERNEL);
 910         if (!sbi->s_debts) {
 911                 printk ("EXT2-fs: not enough memory\n");
 912                 goto failed_mount_group_desc;
 913         }
 914         memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(*sbi->s_debts));
 915         for (i = 0; i < db_count; i++) {
 916                 block = descriptor_loc(sb, logic_sb_block, i);
 917                 sbi->s_group_desc[i] = sb_bread(sb, block);
 918                 if (!sbi->s_group_desc[i]) {
 919                         for (j = 0; j < i; j++)
 920                                 brelse (sbi->s_group_desc[j]);
 921                         printk ("EXT2-fs: unable to read group descriptors\n");
 922                         goto failed_mount_group_desc;
 923                 }
 924         }
 925         if (!ext2_check_descriptors (sb)) {
 926                 printk ("EXT2-fs: group descriptors corrupted!\n");
 927                 goto failed_mount2;
 928         }
 929         sbi->s_gdb_count = db_count;
 930         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 931         spin_lock_init(&sbi->s_next_gen_lock);
 932
 933         percpu_counter_init(&sbi->s_freeblocks_counter,
 934                                 ext2_count_free_blocks(sb));
 935         percpu_counter_init(&sbi->s_freeinodes_counter,
 936                                 ext2_count_free_inodes(sb));
 937         percpu_counter_init(&sbi->s_dirs_counter,
 938                                 ext2_count_dirs(sb));
 939         /*
 940          * set up enough so that it can read an inode
 941          */
 942         sb->s_op = &ext2_sops;
 943         sb->s_export_op = &ext2_export_ops;
 944         sb->s_xattr = ext2_xattr_handlers;
 945         root = iget(sb, EXT2_ROOT_INO);
 946         sb->s_root = d_alloc_root(root);
 947         if (!sb->s_root) {
 948                 iput(root);
 949                 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
 950                 goto failed_mount3;
 951         }
 952         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
 953                 dput(sb->s_root);
 954                 sb->s_root = NULL;
 955                 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
 956                 goto failed_mount3;
 957         }
 958         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 959                 ext2_warning(sb, __FUNCTION__,
 960                         "mounting ext3 filesystem as ext2");
 961         ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
 962         return 0;
 963
 964 cantfind_ext2:
 965         if (!silent)
 966                 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
 967                        sb->s_id);
 968         goto failed_mount;
 969 failed_mount3:
 970         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 971         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 972         percpu_counter_destroy(&sbi->s_dirs_counter);
 973 failed_mount2:
 974         for (i = 0; i < db_count; i++)
 975                 brelse(sbi->s_group_desc[i]);
 976 failed_mount_group_desc:
 977         kfree(sbi->s_group_desc);
 978         kfree(sbi->s_debts);
 979 failed_mount:
 980         brelse(bh);
 981 failed_sbi:
 982         sb->s_fs_info = NULL;
 983         kfree(sbi);
 984         return -EINVAL;
 985 }
 986
 987 static void ext2_commit_super (struct super_block * sb,
 988                                struct ext2_super_block * es)
 989 {
 990         es->s_wtime = cpu_to_le32(get_seconds());
 991         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
 992         sb->s_dirt = 0;
 993 }
 994
 995 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
 996 {
 997         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
 998         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
 999         es->s_wtime = cpu_to_le32(get_seconds());
1000         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1001         sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1002         sb->s_dirt = 0;
1003 }
1004
1005 /*
1006  * In the second extended file system, it is not necessary to
1007  * write the super block since we use a mapping of the
1008  * disk super block in a buffer.
1009  *
1010  * However, this function is still used to set the fs valid
1011  * flags to 0.  We need to set this flag to 0 since the fs
1012  * may have been checked while mounted and e2fsck may have
1013  * set s_state to EXT2_VALID_FS after some corrections.
1014  */
1015
1016 void ext2_write_super (struct super_block * sb)
1017 {
1018         struct ext2_super_block * es;
1019         lock_kernel();
1020         if (!(sb->s_flags & MS_RDONLY)) {
1021                 es = EXT2_SB(sb)->s_es;
1022
1023                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
1024                         ext2_debug ("setting valid to 0\n");
1025                         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
1026                                                   ~EXT2_VALID_FS);
1027                         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1028                         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1029                         es->s_mtime = cpu_to_le32(get_seconds());
1030                         ext2_sync_super(sb, es);
1031                 } else
1032                         ext2_commit_super (sb, es);
1033         }
1034         sb->s_dirt = 0;
1035         unlock_kernel();
1036 }
1037
1038 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1039 {
1040         struct ext2_sb_info * sbi = EXT2_SB(sb);
1041         struct ext2_super_block * es;
1042         unsigned long old_mount_opt = sbi->s_mount_opt;
1043         struct ext2_mount_options old_opts;
1044         unsigned long old_sb_flags;
1045         int err;
1046
1047         /* Store the old options */
1048         old_sb_flags = sb->s_flags;
1049         old_opts.s_mount_opt = sbi->s_mount_opt;
1050         old_opts.s_resuid = sbi->s_resuid;
1051         old_opts.s_resgid = sbi->s_resgid;
1052
1053         /*
1054          * Allow the "check" option to be passed as a remount option.
1055          */
1056         if (!parse_options (data, sbi)) {
1057                 err = -EINVAL;
1058                 goto restore_opts;
1059         }
1060
1061         if ((sbi->s_mount_opt & EXT2_MOUNT_TAGGED) &&
1062                 !(sb->s_flags & MS_TAGGED)) {
1063                 printk("EXT2-fs: %s: tagging not permitted on remount.\n",
1064                        sb->s_id);
1065                 return -EINVAL;
1066         }
1067
1068         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1069                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1070
1071         es = sbi->s_es;
1072         if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1073             (old_mount_opt & EXT2_MOUNT_XIP)) &&
1074             invalidate_inodes(sb))
1075                 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1076                              "xip remain in cache (no functional problem)");
1077         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1078                 return 0;
1079         if (*flags & MS_RDONLY) {
1080                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1081                     !(sbi->s_mount_state & EXT2_VALID_FS))
1082                         return 0;
1083                 /*
1084                  * OK, we are remounting a valid rw partition rdonly, so set
1085                  * the rdonly flag and then mark the partition as valid again.
1086                  */
1087                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1088                 es->s_mtime = cpu_to_le32(get_seconds());
1089         } else {
1090                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1091                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1092                 if (ret) {
1093                         printk("EXT2-fs: %s: couldn't remount RDWR because of "
1094                                "unsupported optional features (%x).\n",
1095                                sb->s_id, le32_to_cpu(ret));
1096                         err = -EROFS;
1097                         goto restore_opts;
1098                 }
1099                 /*
1100                  * Mounting a RDONLY partition read-write, so reread and
1101                  * store the current valid flag.  (It may have been changed
1102                  * by e2fsck since we originally mounted the partition.)
1103                  */
1104                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1105                 if (!ext2_setup_super (sb, es, 0))
1106                         sb->s_flags &= ~MS_RDONLY;
1107         }
1108         ext2_sync_super(sb, es);
1109         return 0;
1110 restore_opts:
1111         sbi->s_mount_opt = old_opts.s_mount_opt;
1112         sbi->s_resuid = old_opts.s_resuid;
1113         sbi->s_resgid = old_opts.s_resgid;
1114         sb->s_flags = old_sb_flags;
1115         return err;
1116 }
1117
1118 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1119 {
1120         struct super_block *sb = dentry->d_sb;
1121         struct ext2_sb_info *sbi = EXT2_SB(sb);
1122         struct ext2_super_block *es = sbi->s_es;
1123         unsigned long overhead;
1124         int i;
1125         u64 fsid;
1126
1127         if (test_opt (sb, MINIX_DF))
1128                 overhead = 0;
1129         else {
1130                 /*
1131                  * Compute the overhead (FS structures)
1132                  */
1133
1134                 /*
1135                  * All of the blocks before first_data_block are
1136                  * overhead
1137                  */
1138                 overhead = le32_to_cpu(es->s_first_data_block);
1139
1140                 /*
1141                  * Add the overhead attributed to the superblock and
1142                  * block group descriptors.  If the sparse superblocks
1143                  * feature is turned on, then not all groups have this.
1144                  */
1145                 for (i = 0; i < sbi->s_groups_count; i++)
1146                         overhead += ext2_bg_has_super(sb, i) +
1147                                 ext2_bg_num_gdb(sb, i);
1148
1149                 /*
1150                  * Every block group has an inode bitmap, a block
1151                  * bitmap, and an inode table.
1152                  */
1153                 overhead += (sbi->s_groups_count *
1154                              (2 + sbi->s_itb_per_group));
1155         }
1156
1157         buf->f_type = EXT2_SUPER_MAGIC;
1158         buf->f_bsize = sb->s_blocksize;
1159         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - overhead;
1160         buf->f_bfree = ext2_count_free_blocks(sb);
1161         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1162         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1163                 buf->f_bavail = 0;
1164         buf->f_files = le32_to_cpu(es->s_inodes_count);
1165         buf->f_ffree = ext2_count_free_inodes(sb);
1166         buf->f_namelen = EXT2_NAME_LEN;
1167         fsid = le64_to_cpup((void *)es->s_uuid) ^
1168                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1169         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1170         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1171         return 0;
1172 }
1173
1174 static int ext2_get_sb(struct file_system_type *fs_type,
1175         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1176 {
1177         return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1178 }
1179
1180 #ifdef CONFIG_QUOTA
1181
1182 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1183  * acquiring the locks... As quota files are never truncated and quota code
1184  * itself serializes the operations (and noone else should touch the files)
1185  * we don't have to be afraid of races */
1186 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1187                                size_t len, loff_t off)
1188 {
1189         struct inode *inode = sb_dqopt(sb)->files[type];
1190         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1191         int err = 0;
1192         int offset = off & (sb->s_blocksize - 1);
1193         int tocopy;
1194         size_t toread;
1195         struct buffer_head tmp_bh;
1196         struct buffer_head *bh;
1197         loff_t i_size = i_size_read(inode);
1198
1199         if (off > i_size)
1200                 return 0;
1201         if (off+len > i_size)
1202                 len = i_size-off;
1203         toread = len;
1204         while (toread > 0) {
1205                 tocopy = sb->s_blocksize - offset < toread ?
1206                                 sb->s_blocksize - offset : toread;
1207
1208                 tmp_bh.b_state = 0;
1209                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1210                 if (err)
1211                         return err;
1212                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1213                         memset(data, 0, tocopy);
1214                 else {
1215                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1216                         if (!bh)
1217                                 return -EIO;
1218                         memcpy(data, bh->b_data+offset, tocopy);
1219                         brelse(bh);
1220                 }
1221                 offset = 0;
1222                 toread -= tocopy;
1223                 data += tocopy;
1224                 blk++;
1225         }
1226         return len;
1227 }
1228
1229 /* Write to quotafile */
1230 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1231                                 const char *data, size_t len, loff_t off)
1232 {
1233         struct inode *inode = sb_dqopt(sb)->files[type];
1234         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1235         int err = 0;
1236         int offset = off & (sb->s_blocksize - 1);
1237         int tocopy;
1238         size_t towrite = len;
1239         struct buffer_head tmp_bh;
1240         struct buffer_head *bh;
1241
1242         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1243         while (towrite > 0) {
1244                 tocopy = sb->s_blocksize - offset < towrite ?
1245                                 sb->s_blocksize - offset : towrite;
1246
1247                 tmp_bh.b_state = 0;
1248                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1249                 if (err)
1250                         goto out;
1251                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1252                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1253                 else
1254                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1255                 if (!bh) {
1256                         err = -EIO;
1257                         goto out;
1258                 }
1259                 lock_buffer(bh);
1260                 memcpy(bh->b_data+offset, data, tocopy);
1261                 flush_dcache_page(bh->b_page);
1262                 set_buffer_uptodate(bh);
1263                 mark_buffer_dirty(bh);
1264                 unlock_buffer(bh);
1265                 brelse(bh);
1266                 offset = 0;
1267                 towrite -= tocopy;
1268                 data += tocopy;
1269                 blk++;
1270         }
1271 out:
1272         if (len == towrite)
1273                 return err;
1274         if (inode->i_size < off+len-towrite)
1275                 i_size_write(inode, off+len-towrite);
1276         inode->i_version++;
1277         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1278         mark_inode_dirty(inode);
1279         mutex_unlock(&inode->i_mutex);
1280         return len - towrite;
1281 }
1282
1283 #endif
1284
1285 static struct file_system_type ext2_fs_type = {
1286         .owner          = THIS_MODULE,
1287         .name           = "ext2",
1288         .get_sb         = ext2_get_sb,
1289         .kill_sb        = kill_block_super,
1290         .fs_flags       = FS_REQUIRES_DEV,
1291 };
1292
1293 static int __init init_ext2_fs(void)
1294 {
1295         int err = init_ext2_xattr();
1296         if (err)
1297                 return err;
1298         err = init_inodecache();
1299         if (err)
1300                 goto out1;
1301         err = register_filesystem(&ext2_fs_type);
1302         if (err)
1303                 goto out;
1304         return 0;
1305 out:
1306         destroy_inodecache();
1307 out1:
1308         exit_ext2_xattr();
1309         return err;
1310 }
1311
1312 static void __exit exit_ext2_fs(void)
1313 {
1314         unregister_filesystem(&ext2_fs_type);
1315         destroy_inodecache();
1316         exit_ext2_xattr();
1317 }
1318
1319 module_init(init_ext2_fs)
1320 module_exit(exit_ext2_fs)