SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/exportfs.h>
  29 #include <linux/smp_lock.h>
  30 #include <linux/vfs.h>
  31 #include <linux/seq_file.h>
  32 #include <linux/mount.h>
  33 #include <linux/log2.h>
  34 #include <linux/quotaops.h>
  35 #include <asm/uaccess.h>
  36 #include "ext2.h"
  37 #include "xattr.h"
  38 #include "acl.h"
  39 #include "xip.h"
  40
  41 static void ext2_sync_super(struct super_block *sb,
  42                             struct ext2_super_block *es);
  43 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  44 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  45
  46 void ext2_error (struct super_block * sb, const char * function,
  47                  const char * fmt, ...)
  48 {
  49         va_list args;
  50         struct ext2_sb_info *sbi = EXT2_SB(sb);
  51         struct ext2_super_block *es = sbi->s_es;
  52
  53         if (!(sb->s_flags & MS_RDONLY)) {
  54                 sbi->s_mount_state |= EXT2_ERROR_FS;
  55                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  56                 ext2_sync_super(sb, es);
  57         }
  58
  59         va_start(args, fmt);
  60         printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
  61         vprintk(fmt, args);
  62         printk("\n");
  63         va_end(args);
  64
  65         if (test_opt(sb, ERRORS_PANIC))
  66                 panic("EXT2-fs panic from previous error\n");
  67         if (test_opt(sb, ERRORS_RO)) {
  68                 printk("Remounting filesystem read-only\n");
  69                 sb->s_flags |= MS_RDONLY;
  70         }
  71 }
  72
  73 void ext2_warning (struct super_block * sb, const char * function,
  74                    const char * fmt, ...)
  75 {
  76         va_list args;
  77
  78         va_start(args, fmt);
  79         printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
  80                sb->s_id, function);
  81         vprintk(fmt, args);
  82         printk("\n");
  83         va_end(args);
  84 }
  85
  86 void ext2_update_dynamic_rev(struct super_block *sb)
  87 {
  88         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
  89
  90         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
  91                 return;
  92
  93         ext2_warning(sb, __func__,
  94                      "updating to rev %d because of new feature flag, "
  95                      "running e2fsck is recommended",
  96                      EXT2_DYNAMIC_REV);
  97
  98         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
  99         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 100         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 101         /* leave es->s_feature_*compat flags alone */
 102         /* es->s_uuid will be set by e2fsck if empty */
 103
 104         /*
 105          * The rest of the superblock fields should be zero, and if not it
 106          * means they are likely already in use, so leave them alone.  We
 107          * can leave it up to e2fsck to clean up any inconsistencies there.
 108          */
 109 }
 110
 111 static void ext2_put_super (struct super_block * sb)
 112 {
 113         int db_count;
 114         int i;
 115         struct ext2_sb_info *sbi = EXT2_SB(sb);
 116
 117         if (sb->s_dirt)
 118                 ext2_write_super(sb);
 119
 120         ext2_xattr_put_super(sb);
 121         if (!(sb->s_flags & MS_RDONLY)) {
 122                 struct ext2_super_block *es = sbi->s_es;
 123
 124                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 125                 ext2_sync_super(sb, es);
 126         }
 127         db_count = sbi->s_gdb_count;
 128         for (i = 0; i < db_count; i++)
 129                 if (sbi->s_group_desc[i])
 130                         brelse (sbi->s_group_desc[i]);
 131         kfree(sbi->s_group_desc);
 132         kfree(sbi->s_debts);
 133         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 134         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 135         percpu_counter_destroy(&sbi->s_dirs_counter);
 136         brelse (sbi->s_sbh);
 137         sb->s_fs_info = NULL;
 138         kfree(sbi->s_blockgroup_lock);
 139         kfree(sbi);
 140
 141         return;
 142 }
 143
 144 static struct kmem_cache * ext2_inode_cachep;
 145
 146 static struct inode *ext2_alloc_inode(struct super_block *sb)
 147 {
 148         struct ext2_inode_info *ei;
 149         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 150         if (!ei)
 151                 return NULL;
 152 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 153         ei->i_acl = EXT2_ACL_NOT_CACHED;
 154         ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 155 #endif
 156         ei->i_block_alloc_info = NULL;
 157         ei->vfs_inode.i_version = 1;
 158         return &ei->vfs_inode;
 159 }
 160
 161 static void ext2_destroy_inode(struct inode *inode)
 162 {
 163         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 164 }
 165
 166 static void init_once(void *foo)
 167 {
 168         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 169
 170         rwlock_init(&ei->i_meta_lock);
 171 #ifdef CONFIG_EXT2_FS_XATTR
 172         init_rwsem(&ei->xattr_sem);
 173 #endif
 174         mutex_init(&ei->truncate_mutex);
 175         inode_init_once(&ei->vfs_inode);
 176 }
 177
 178 static int init_inodecache(void)
 179 {
 180         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 181                                              sizeof(struct ext2_inode_info),
 182                                              0, (SLAB_RECLAIM_ACCOUNT|
 183                                                 SLAB_MEM_SPREAD),
 184                                              init_once);
 185         if (ext2_inode_cachep == NULL)
 186                 return -ENOMEM;
 187         return 0;
 188 }
 189
 190 static void destroy_inodecache(void)
 191 {
 192         kmem_cache_destroy(ext2_inode_cachep);
 193 }
 194
 195 static void ext2_clear_inode(struct inode *inode)
 196 {
 197         struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
 198 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 199         struct ext2_inode_info *ei = EXT2_I(inode);
 200
 201         if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
 202                 posix_acl_release(ei->i_acl);
 203                 ei->i_acl = EXT2_ACL_NOT_CACHED;
 204         }
 205         if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
 206                 posix_acl_release(ei->i_default_acl);
 207                 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 208         }
 209 #endif
 210         ext2_discard_reservation(inode);
 211         EXT2_I(inode)->i_block_alloc_info = NULL;
 212         if (unlikely(rsv))
 213                 kfree(rsv);
 214 }
 215
 216 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
 217 {
 218         struct super_block *sb = vfs->mnt_sb;
 219         struct ext2_sb_info *sbi = EXT2_SB(sb);
 220         struct ext2_super_block *es = sbi->s_es;
 221         unsigned long def_mount_opts;
 222
 223         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 224
 225         if (sbi->s_sb_block != 1)
 226                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 227         if (test_opt(sb, MINIX_DF))
 228                 seq_puts(seq, ",minixdf");
 229         if (test_opt(sb, GRPID))
 230                 seq_puts(seq, ",grpid");
 231         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 232                 seq_puts(seq, ",nogrpid");
 233         if (sbi->s_resuid != EXT2_DEF_RESUID ||
 234             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 235                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 236         }
 237         if (sbi->s_resgid != EXT2_DEF_RESGID ||
 238             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 239                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 240         }
 241         if (test_opt(sb, ERRORS_RO)) {
 242                 int def_errors = le16_to_cpu(es->s_errors);
 243
 244                 if (def_errors == EXT2_ERRORS_PANIC ||
 245                     def_errors == EXT2_ERRORS_CONTINUE) {
 246                         seq_puts(seq, ",errors=remount-ro");
 247                 }
 248         }
 249         if (test_opt(sb, ERRORS_CONT))
 250                 seq_puts(seq, ",errors=continue");
 251         if (test_opt(sb, ERRORS_PANIC))
 252                 seq_puts(seq, ",errors=panic");
 253         if (test_opt(sb, NO_UID32))
 254                 seq_puts(seq, ",nouid32");
 255         if (test_opt(sb, DEBUG))
 256                 seq_puts(seq, ",debug");
 257         if (test_opt(sb, OLDALLOC))
 258                 seq_puts(seq, ",oldalloc");
 259
 260 #ifdef CONFIG_EXT2_FS_XATTR
 261         if (test_opt(sb, XATTR_USER))
 262                 seq_puts(seq, ",user_xattr");
 263         if (!test_opt(sb, XATTR_USER) &&
 264             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 265                 seq_puts(seq, ",nouser_xattr");
 266         }
 267 #endif
 268
 269 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 270         if (test_opt(sb, POSIX_ACL))
 271                 seq_puts(seq, ",acl");
 272         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 273                 seq_puts(seq, ",noacl");
 274 #endif
 275
 276         if (test_opt(sb, NOBH))
 277                 seq_puts(seq, ",nobh");
 278
 279 #if defined(CONFIG_QUOTA)
 280         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 281                 seq_puts(seq, ",usrquota");
 282
 283         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 284                 seq_puts(seq, ",grpquota");
 285 #endif
 286
 287 #if defined(CONFIG_EXT2_FS_XIP)
 288         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 289                 seq_puts(seq, ",xip");
 290 #endif
 291
 292         if (!test_opt(sb, RESERVATION))
 293                 seq_puts(seq, ",noreservation");
 294
 295         return 0;
 296 }
 297
 298 #ifdef CONFIG_QUOTA
 299 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 300 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 301 #endif
 302
 303 static const struct super_operations ext2_sops = {
 304         .alloc_inode    = ext2_alloc_inode,
 305         .destroy_inode  = ext2_destroy_inode,
 306         .write_inode    = ext2_write_inode,
 307         .delete_inode   = ext2_delete_inode,
 308         .put_super      = ext2_put_super,
 309         .write_super    = ext2_write_super,
 310         .statfs         = ext2_statfs,
 311         .remount_fs     = ext2_remount,
 312         .clear_inode    = ext2_clear_inode,
 313         .show_options   = ext2_show_options,
 314 #ifdef CONFIG_QUOTA
 315         .quota_read     = ext2_quota_read,
 316         .quota_write    = ext2_quota_write,
 317 #endif
 318 };
 319
 320 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 321                 u64 ino, u32 generation)
 322 {
 323         struct inode *inode;
 324
 325         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 326                 return ERR_PTR(-ESTALE);
 327         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 328                 return ERR_PTR(-ESTALE);
 329
 330         /* iget isn't really right if the inode is currently unallocated!!
 331          * ext2_read_inode currently does appropriate checks, but
 332          * it might be "neater" to call ext2_get_inode first and check
 333          * if the inode is valid.....
 334          */
 335         inode = ext2_iget(sb, ino);
 336         if (IS_ERR(inode))
 337                 return ERR_CAST(inode);
 338         if (generation && inode->i_generation != generation) {
 339                 /* we didn't find the right inode.. */
 340                 iput(inode);
 341                 return ERR_PTR(-ESTALE);
 342         }
 343         return inode;
 344 }
 345
 346 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 347                 int fh_len, int fh_type)
 348 {
 349         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 350                                     ext2_nfs_get_inode);
 351 }
 352
 353 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 354                 int fh_len, int fh_type)
 355 {
 356         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 357                                     ext2_nfs_get_inode);
 358 }
 359
 360 /* Yes, most of these are left as NULL!!
 361  * A NULL value implies the default, which works with ext2-like file
 362  * systems, but can be improved upon.
 363  * Currently only get_parent is required.
 364  */
 365 static const struct export_operations ext2_export_ops = {
 366         .fh_to_dentry = ext2_fh_to_dentry,
 367         .fh_to_parent = ext2_fh_to_parent,
 368         .get_parent = ext2_get_parent,
 369 };
 370
 371 static unsigned long get_sb_block(void **data)
 372 {
 373         unsigned long   sb_block;
 374         char            *options = (char *) *data;
 375
 376         if (!options || strncmp(options, "sb=", 3) != 0)
 377                 return 1;       /* Default location */
 378         options += 3;
 379         sb_block = simple_strtoul(options, &options, 0);
 380         if (*options && *options != ',') {
 381                 printk("EXT2-fs: Invalid sb specification: %s\n",
 382                        (char *) *data);
 383                 return 1;
 384         }
 385         if (*options == ',')
 386                 options++;
 387         *data = (void *) options;
 388         return sb_block;
 389 }
 390
 391 enum {
 392         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 393         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 394         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 395         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 396         Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 397         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 398 };
 399
 400 static const match_table_t tokens = {
 401         {Opt_bsd_df, "bsddf"},
 402         {Opt_minix_df, "minixdf"},
 403         {Opt_grpid, "grpid"},
 404         {Opt_grpid, "bsdgroups"},
 405         {Opt_nogrpid, "nogrpid"},
 406         {Opt_nogrpid, "sysvgroups"},
 407         {Opt_resgid, "resgid=%u"},
 408         {Opt_resuid, "resuid=%u"},
 409         {Opt_sb, "sb=%u"},
 410         {Opt_err_cont, "errors=continue"},
 411         {Opt_err_panic, "errors=panic"},
 412         {Opt_err_ro, "errors=remount-ro"},
 413         {Opt_nouid32, "nouid32"},
 414         {Opt_nocheck, "check=none"},
 415         {Opt_nocheck, "nocheck"},
 416         {Opt_debug, "debug"},
 417         {Opt_oldalloc, "oldalloc"},
 418         {Opt_orlov, "orlov"},
 419         {Opt_nobh, "nobh"},
 420         {Opt_user_xattr, "user_xattr"},
 421         {Opt_nouser_xattr, "nouser_xattr"},
 422         {Opt_acl, "acl"},
 423         {Opt_noacl, "noacl"},
 424         {Opt_xip, "xip"},
 425         {Opt_grpquota, "grpquota"},
 426         {Opt_ignore, "noquota"},
 427         {Opt_quota, "quota"},
 428         {Opt_usrquota, "usrquota"},
 429         {Opt_reservation, "reservation"},
 430         {Opt_noreservation, "noreservation"},
 431         {Opt_err, NULL}
 432 };
 433
 434 static int parse_options (char * options,
 435                           struct ext2_sb_info *sbi)
 436 {
 437         char * p;
 438         substring_t args[MAX_OPT_ARGS];
 439         int option;
 440
 441         if (!options)
 442                 return 1;
 443
 444         while ((p = strsep (&options, ",")) != NULL) {
 445                 int token;
 446                 if (!*p)
 447                         continue;
 448
 449                 token = match_token(p, tokens, args);
 450                 switch (token) {
 451                 case Opt_bsd_df:
 452                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 453                         break;
 454                 case Opt_minix_df:
 455                         set_opt (sbi->s_mount_opt, MINIX_DF);
 456                         break;
 457                 case Opt_grpid:
 458                         set_opt (sbi->s_mount_opt, GRPID);
 459                         break;
 460                 case Opt_nogrpid:
 461                         clear_opt (sbi->s_mount_opt, GRPID);
 462                         break;
 463                 case Opt_resuid:
 464                         if (match_int(&args[0], &option))
 465                                 return 0;
 466                         sbi->s_resuid = option;
 467                         break;
 468                 case Opt_resgid:
 469                         if (match_int(&args[0], &option))
 470                                 return 0;
 471                         sbi->s_resgid = option;
 472                         break;
 473                 case Opt_sb:
 474                         /* handled by get_sb_block() instead of here */
 475                         /* *sb_block = match_int(&args[0]); */
 476                         break;
 477                 case Opt_err_panic:
 478                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 479                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 480                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 481                         break;
 482                 case Opt_err_ro:
 483                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 484                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 485                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 486                         break;
 487                 case Opt_err_cont:
 488                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 489                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 490                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 491                         break;
 492                 case Opt_nouid32:
 493                         set_opt (sbi->s_mount_opt, NO_UID32);
 494                         break;
 495                 case Opt_nocheck:
 496                         clear_opt (sbi->s_mount_opt, CHECK);
 497                         break;
 498                 case Opt_debug:
 499                         set_opt (sbi->s_mount_opt, DEBUG);
 500                         break;
 501                 case Opt_oldalloc:
 502                         set_opt (sbi->s_mount_opt, OLDALLOC);
 503                         break;
 504                 case Opt_orlov:
 505                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 506                         break;
 507                 case Opt_nobh:
 508                         set_opt (sbi->s_mount_opt, NOBH);
 509                         break;
 510 #ifdef CONFIG_EXT2_FS_XATTR
 511                 case Opt_user_xattr:
 512                         set_opt (sbi->s_mount_opt, XATTR_USER);
 513                         break;
 514                 case Opt_nouser_xattr:
 515                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 516                         break;
 517 #else
 518                 case Opt_user_xattr:
 519                 case Opt_nouser_xattr:
 520                         printk("EXT2 (no)user_xattr options not supported\n");
 521                         break;
 522 #endif
 523 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 524                 case Opt_acl:
 525                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 526                         break;
 527                 case Opt_noacl:
 528                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 529                         break;
 530 #else
 531                 case Opt_acl:
 532                 case Opt_noacl:
 533                         printk("EXT2 (no)acl options not supported\n");
 534                         break;
 535 #endif
 536                 case Opt_xip:
 537 #ifdef CONFIG_EXT2_FS_XIP
 538                         set_opt (sbi->s_mount_opt, XIP);
 539 #else
 540                         printk("EXT2 xip option not supported\n");
 541 #endif
 542                         break;
 543
 544 #if defined(CONFIG_QUOTA)
 545                 case Opt_quota:
 546                 case Opt_usrquota:
 547                         set_opt(sbi->s_mount_opt, USRQUOTA);
 548                         break;
 549
 550                 case Opt_grpquota:
 551                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 552                         break;
 553 #else
 554                 case Opt_quota:
 555                 case Opt_usrquota:
 556                 case Opt_grpquota:
 557                         printk(KERN_ERR
 558                                 "EXT2-fs: quota operations not supported.\n");
 559
 560                         break;
 561 #endif
 562
 563                 case Opt_reservation:
 564                         set_opt(sbi->s_mount_opt, RESERVATION);
 565                         printk("reservations ON\n");
 566                         break;
 567                 case Opt_noreservation:
 568                         clear_opt(sbi->s_mount_opt, RESERVATION);
 569                         printk("reservations OFF\n");
 570                         break;
 571                 case Opt_ignore:
 572                         break;
 573                 default:
 574                         return 0;
 575                 }
 576         }
 577         return 1;
 578 }
 579
 580 static int ext2_setup_super (struct super_block * sb,
 581                               struct ext2_super_block * es,
 582                               int read_only)
 583 {
 584         int res = 0;
 585         struct ext2_sb_info *sbi = EXT2_SB(sb);
 586
 587         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 588                 printk ("EXT2-fs warning: revision level too high, "
 589                         "forcing read-only mode\n");
 590                 res = MS_RDONLY;
 591         }
 592         if (read_only)
 593                 return res;
 594         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 595                 printk ("EXT2-fs warning: mounting unchecked fs, "
 596                         "running e2fsck is recommended\n");
 597         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 598                 printk ("EXT2-fs warning: mounting fs with errors, "
 599                         "running e2fsck is recommended\n");
 600         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 601                  le16_to_cpu(es->s_mnt_count) >=
 602                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 603                 printk ("EXT2-fs warning: maximal mount count reached, "
 604                         "running e2fsck is recommended\n");
 605         else if (le32_to_cpu(es->s_checkinterval) &&
 606                 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 607                 printk ("EXT2-fs warning: checktime reached, "
 608                         "running e2fsck is recommended\n");
 609         if (!le16_to_cpu(es->s_max_mnt_count))
 610                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 611         le16_add_cpu(&es->s_mnt_count, 1);
 612         ext2_write_super(sb);
 613         if (test_opt (sb, DEBUG))
 614                 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
 615                         "bpg=%lu, ipg=%lu, mo=%04lx]\n",
 616                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 617                         sbi->s_frag_size,
 618                         sbi->s_groups_count,
 619                         EXT2_BLOCKS_PER_GROUP(sb),
 620                         EXT2_INODES_PER_GROUP(sb),
 621                         sbi->s_mount_opt);
 622         return res;
 623 }
 624
 625 static int ext2_check_descriptors(struct super_block *sb)
 626 {
 627         int i;
 628         struct ext2_sb_info *sbi = EXT2_SB(sb);
 629
 630         ext2_debug ("Checking group descriptors");
 631
 632         for (i = 0; i < sbi->s_groups_count; i++) {
 633                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 634                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 635                 ext2_fsblk_t last_block;
 636
 637                 if (i == sbi->s_groups_count - 1)
 638                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 639                 else
 640                         last_block = first_block +
 641                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 642
 643                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 644                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 645                 {
 646                         ext2_error (sb, "ext2_check_descriptors",
 647                                     "Block bitmap for group %d"
 648                                     " not in group (block %lu)!",
 649                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 650                         return 0;
 651                 }
 652                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 653                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 654                 {
 655                         ext2_error (sb, "ext2_check_descriptors",
 656                                     "Inode bitmap for group %d"
 657                                     " not in group (block %lu)!",
 658                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 659                         return 0;
 660                 }
 661                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 662                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 663                     last_block)
 664                 {
 665                         ext2_error (sb, "ext2_check_descriptors",
 666                                     "Inode table for group %d"
 667                                     " not in group (block %lu)!",
 668                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 669                         return 0;
 670                 }
 671         }
 672         return 1;
 673 }
 674
 675 /*
 676  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 677  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 678  * We need to be 1 filesystem block less than the 2^32 sector limit.
 679  */
 680 static loff_t ext2_max_size(int bits)
 681 {
 682         loff_t res = EXT2_NDIR_BLOCKS;
 683         int meta_blocks;
 684         loff_t upper_limit;
 685
 686         /* This is calculated to be the largest file size for a
 687          * dense, file such that the total number of
 688          * sectors in the file, including data and all indirect blocks,
 689          * does not exceed 2^32 -1
 690          * __u32 i_blocks representing the total number of
 691          * 512 bytes blocks of the file
 692          */
 693         upper_limit = (1LL << 32) - 1;
 694
 695         /* total blocks in file system block size */
 696         upper_limit >>= (bits - 9);
 697
 698
 699         /* indirect blocks */
 700         meta_blocks = 1;
 701         /* double indirect blocks */
 702         meta_blocks += 1 + (1LL << (bits-2));
 703         /* tripple indirect blocks */
 704         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 705
 706         upper_limit -= meta_blocks;
 707         upper_limit <<= bits;
 708
 709         res += 1LL << (bits-2);
 710         res += 1LL << (2*(bits-2));
 711         res += 1LL << (3*(bits-2));
 712         res <<= bits;
 713         if (res > upper_limit)
 714                 res = upper_limit;
 715
 716         if (res > MAX_LFS_FILESIZE)
 717                 res = MAX_LFS_FILESIZE;
 718
 719         return res;
 720 }
 721
 722 static unsigned long descriptor_loc(struct super_block *sb,
 723                                     unsigned long logic_sb_block,
 724                                     int nr)
 725 {
 726         struct ext2_sb_info *sbi = EXT2_SB(sb);
 727         unsigned long bg, first_meta_bg;
 728         int has_super = 0;
 729
 730         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 731
 732         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 733             nr < first_meta_bg)
 734                 return (logic_sb_block + nr + 1);
 735         bg = sbi->s_desc_per_block * nr;
 736         if (ext2_bg_has_super(sb, bg))
 737                 has_super = 1;
 738
 739         return ext2_group_first_block_no(sb, bg) + has_super;
 740 }
 741
 742 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 743 {
 744         struct buffer_head * bh;
 745         struct ext2_sb_info * sbi;
 746         struct ext2_super_block * es;
 747         struct inode *root;
 748         unsigned long block;
 749         unsigned long sb_block = get_sb_block(&data);
 750         unsigned long logic_sb_block;
 751         unsigned long offset = 0;
 752         unsigned long def_mount_opts;
 753         long ret = -EINVAL;
 754         int blocksize = BLOCK_SIZE;
 755         int db_count;
 756         int i, j;
 757         __le32 features;
 758         int err;
 759
 760         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 761         if (!sbi)
 762                 return -ENOMEM;
 763
 764         sbi->s_blockgroup_lock =
 765                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 766         if (!sbi->s_blockgroup_lock) {
 767                 kfree(sbi);
 768                 return -ENOMEM;
 769         }
 770         sb->s_fs_info = sbi;
 771         sbi->s_sb_block = sb_block;
 772
 773         /*
 774          * See what the current blocksize for the device is, and
 775          * use that as the blocksize.  Otherwise (or if the blocksize
 776          * is smaller than the default) use the default.
 777          * This is important for devices that have a hardware
 778          * sectorsize that is larger than the default.
 779          */
 780         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 781         if (!blocksize) {
 782                 printk ("EXT2-fs: unable to set blocksize\n");
 783                 goto failed_sbi;
 784         }
 785
 786         /*
 787          * If the superblock doesn't start on a hardware sector boundary,
 788          * calculate the offset.
 789          */
 790         if (blocksize != BLOCK_SIZE) {
 791                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 792                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 793         } else {
 794                 logic_sb_block = sb_block;
 795         }
 796
 797         if (!(bh = sb_bread(sb, logic_sb_block))) {
 798                 printk ("EXT2-fs: unable to read superblock\n");
 799                 goto failed_sbi;
 800         }
 801         /*
 802          * Note: s_es must be initialized as soon as possible because
 803          *       some ext2 macro-instructions depend on its value
 804          */
 805         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 806         sbi->s_es = es;
 807         sb->s_magic = le16_to_cpu(es->s_magic);
 808
 809         if (sb->s_magic != EXT2_SUPER_MAGIC)
 810                 goto cantfind_ext2;
 811
 812         /* Set defaults before we parse the mount options */
 813         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 814         if (def_mount_opts & EXT2_DEFM_DEBUG)
 815                 set_opt(sbi->s_mount_opt, DEBUG);
 816         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 817                 set_opt(sbi->s_mount_opt, GRPID);
 818         if (def_mount_opts & EXT2_DEFM_UID16)
 819                 set_opt(sbi->s_mount_opt, NO_UID32);
 820 #ifdef CONFIG_EXT2_FS_XATTR
 821         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 822                 set_opt(sbi->s_mount_opt, XATTR_USER);
 823 #endif
 824 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 825         if (def_mount_opts & EXT2_DEFM_ACL)
 826                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 827 #endif
 828
 829         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 830                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 831         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 832                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 833         else
 834                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 835
 836         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 837         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 838
 839         set_opt(sbi->s_mount_opt, RESERVATION);
 840
 841         if (!parse_options ((char *) data, sbi))
 842                 goto failed_mount;
 843
 844         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 845                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 846                  MS_POSIXACL : 0);
 847
 848         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 849                                     EXT2_MOUNT_XIP if not */
 850
 851         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 852             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 853              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 854              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 855                 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
 856                        "running e2fsck is recommended\n");
 857         /*
 858          * Check feature flags regardless of the revision level, since we
 859          * previously didn't change the revision level when setting the flags,
 860          * so there is a chance incompat flags are set on a rev 0 filesystem.
 861          */
 862         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 863         if (features) {
 864                 printk("EXT2-fs: %s: couldn't mount because of "
 865                        "unsupported optional features (%x).\n",
 866                        sb->s_id, le32_to_cpu(features));
 867                 goto failed_mount;
 868         }
 869         if (!(sb->s_flags & MS_RDONLY) &&
 870             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 871                 printk("EXT2-fs: %s: couldn't mount RDWR because of "
 872                        "unsupported optional features (%x).\n",
 873                        sb->s_id, le32_to_cpu(features));
 874                 goto failed_mount;
 875         }
 876
 877         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 878
 879         if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
 880                 if (!silent)
 881                         printk("XIP: Unsupported blocksize\n");
 882                 goto failed_mount;
 883         }
 884
 885         /* If the blocksize doesn't match, re-read the thing.. */
 886         if (sb->s_blocksize != blocksize) {
 887                 brelse(bh);
 888
 889                 if (!sb_set_blocksize(sb, blocksize)) {
 890                         printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
 891                         goto failed_sbi;
 892                 }
 893
 894                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 895                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 896                 bh = sb_bread(sb, logic_sb_block);
 897                 if(!bh) {
 898                         printk("EXT2-fs: Couldn't read superblock on "
 899                                "2nd try.\n");
 900                         goto failed_sbi;
 901                 }
 902                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 903                 sbi->s_es = es;
 904                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 905                         printk ("EXT2-fs: Magic mismatch, very weird !\n");
 906                         goto failed_mount;
 907                 }
 908         }
 909
 910         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 911
 912         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 913                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 914                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 915         } else {
 916                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 917                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 918                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 919                     !is_power_of_2(sbi->s_inode_size) ||
 920                     (sbi->s_inode_size > blocksize)) {
 921                         printk ("EXT2-fs: unsupported inode size: %d\n",
 922                                 sbi->s_inode_size);
 923                         goto failed_mount;
 924                 }
 925         }
 926
 927         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 928                                    le32_to_cpu(es->s_log_frag_size);
 929         if (sbi->s_frag_size == 0)
 930                 goto cantfind_ext2;
 931         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 932
 933         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 934         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 935         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 936
 937         if (EXT2_INODE_SIZE(sb) == 0)
 938                 goto cantfind_ext2;
 939         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 940         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 941                 goto cantfind_ext2;
 942         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 943                                         sbi->s_inodes_per_block;
 944         sbi->s_desc_per_block = sb->s_blocksize /
 945                                         sizeof (struct ext2_group_desc);
 946         sbi->s_sbh = bh;
 947         sbi->s_mount_state = le16_to_cpu(es->s_state);
 948         sbi->s_addr_per_block_bits =
 949                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 950         sbi->s_desc_per_block_bits =
 951                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
 952
 953         if (sb->s_magic != EXT2_SUPER_MAGIC)
 954                 goto cantfind_ext2;
 955
 956         if (sb->s_blocksize != bh->b_size) {
 957                 if (!silent)
 958                         printk ("VFS: Unsupported blocksize on dev "
 959                                 "%s.\n", sb->s_id);
 960                 goto failed_mount;
 961         }
 962
 963         if (sb->s_blocksize != sbi->s_frag_size) {
 964                 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
 965                         sbi->s_frag_size, sb->s_blocksize);
 966                 goto failed_mount;
 967         }
 968
 969         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 970                 printk ("EXT2-fs: #blocks per group too big: %lu\n",
 971                         sbi->s_blocks_per_group);
 972                 goto failed_mount;
 973         }
 974         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 975                 printk ("EXT2-fs: #fragments per group too big: %lu\n",
 976                         sbi->s_frags_per_group);
 977                 goto failed_mount;
 978         }
 979         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 980                 printk ("EXT2-fs: #inodes per group too big: %lu\n",
 981                         sbi->s_inodes_per_group);
 982                 goto failed_mount;
 983         }
 984
 985         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 986                 goto cantfind_ext2;
 987         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
 988                                 le32_to_cpu(es->s_first_data_block) - 1)
 989                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
 990         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 991                    EXT2_DESC_PER_BLOCK(sb);
 992         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
 993         if (sbi->s_group_desc == NULL) {
 994                 printk ("EXT2-fs: not enough memory\n");
 995                 goto failed_mount;
 996         }
 997         bgl_lock_init(sbi->s_blockgroup_lock);
 998         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
 999         if (!sbi->s_debts) {
1000                 printk ("EXT2-fs: not enough memory\n");
1001                 goto failed_mount_group_desc;
1002         }
1003         for (i = 0; i < db_count; i++) {
1004                 block = descriptor_loc(sb, logic_sb_block, i);
1005                 sbi->s_group_desc[i] = sb_bread(sb, block);
1006                 if (!sbi->s_group_desc[i]) {
1007                         for (j = 0; j < i; j++)
1008                                 brelse (sbi->s_group_desc[j]);
1009                         printk ("EXT2-fs: unable to read group descriptors\n");
1010                         goto failed_mount_group_desc;
1011                 }
1012         }
1013         if (!ext2_check_descriptors (sb)) {
1014                 printk ("EXT2-fs: group descriptors corrupted!\n");
1015                 goto failed_mount2;
1016         }
1017         sbi->s_gdb_count = db_count;
1018         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1019         spin_lock_init(&sbi->s_next_gen_lock);
1020
1021         /* per fileystem reservation list head & lock */
1022         spin_lock_init(&sbi->s_rsv_window_lock);
1023         sbi->s_rsv_window_root = RB_ROOT;
1024         /*
1025          * Add a single, static dummy reservation to the start of the
1026          * reservation window list --- it gives us a placeholder for
1027          * append-at-start-of-list which makes the allocation logic
1028          * _much_ simpler.
1029          */
1030         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1031         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1032         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1033         sbi->s_rsv_window_head.rsv_goal_size = 0;
1034         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1035
1036         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1037                                 ext2_count_free_blocks(sb));
1038         if (!err) {
1039                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1040                                 ext2_count_free_inodes(sb));
1041         }
1042         if (!err) {
1043                 err = percpu_counter_init(&sbi->s_dirs_counter,
1044                                 ext2_count_dirs(sb));
1045         }
1046         if (err) {
1047                 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1048                 goto failed_mount3;
1049         }
1050         /*
1051          * set up enough so that it can read an inode
1052          */
1053         sb->s_op = &ext2_sops;
1054         sb->s_export_op = &ext2_export_ops;
1055         sb->s_xattr = ext2_xattr_handlers;
1056         root = ext2_iget(sb, EXT2_ROOT_INO);
1057         if (IS_ERR(root)) {
1058                 ret = PTR_ERR(root);
1059                 goto failed_mount3;
1060         }
1061         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1062                 iput(root);
1063                 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1064                 goto failed_mount3;
1065         }
1066
1067         sb->s_root = d_alloc_root(root);
1068         if (!sb->s_root) {
1069                 iput(root);
1070                 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1071                 ret = -ENOMEM;
1072                 goto failed_mount3;
1073         }
1074         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1075                 ext2_warning(sb, __func__,
1076                         "mounting ext3 filesystem as ext2");
1077         ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1078         return 0;
1079
1080 cantfind_ext2:
1081         if (!silent)
1082                 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1083                        sb->s_id);
1084         goto failed_mount;
1085 failed_mount3:
1086         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1087         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1088         percpu_counter_destroy(&sbi->s_dirs_counter);
1089 failed_mount2:
1090         for (i = 0; i < db_count; i++)
1091                 brelse(sbi->s_group_desc[i]);
1092 failed_mount_group_desc:
1093         kfree(sbi->s_group_desc);
1094         kfree(sbi->s_debts);
1095 failed_mount:
1096         brelse(bh);
1097 failed_sbi:
1098         sb->s_fs_info = NULL;
1099         kfree(sbi->s_blockgroup_lock);
1100         kfree(sbi);
1101         return ret;
1102 }
1103
1104 static void ext2_commit_super (struct super_block * sb,
1105                                struct ext2_super_block * es)
1106 {
1107         es->s_wtime = cpu_to_le32(get_seconds());
1108         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1109         sb->s_dirt = 0;
1110 }
1111
1112 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1113 {
1114         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1115         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1116         es->s_wtime = cpu_to_le32(get_seconds());
1117         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1118         sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1119         sb->s_dirt = 0;
1120 }
1121
1122 /*
1123  * In the second extended file system, it is not necessary to
1124  * write the super block since we use a mapping of the
1125  * disk super block in a buffer.
1126  *
1127  * However, this function is still used to set the fs valid
1128  * flags to 0.  We need to set this flag to 0 since the fs
1129  * may have been checked while mounted and e2fsck may have
1130  * set s_state to EXT2_VALID_FS after some corrections.
1131  */
1132
1133 void ext2_write_super (struct super_block * sb)
1134 {
1135         struct ext2_super_block * es;
1136         lock_kernel();
1137         if (!(sb->s_flags & MS_RDONLY)) {
1138                 es = EXT2_SB(sb)->s_es;
1139
1140                 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1141                         ext2_debug ("setting valid to 0\n");
1142                         es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1143                         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1144                         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1145                         es->s_mtime = cpu_to_le32(get_seconds());
1146                         ext2_sync_super(sb, es);
1147                 } else
1148                         ext2_commit_super (sb, es);
1149         }
1150         sb->s_dirt = 0;
1151         unlock_kernel();
1152 }
1153
1154 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1155 {
1156         struct ext2_sb_info * sbi = EXT2_SB(sb);
1157         struct ext2_super_block * es;
1158         unsigned long old_mount_opt = sbi->s_mount_opt;
1159         struct ext2_mount_options old_opts;
1160         unsigned long old_sb_flags;
1161         int err;
1162
1163         /* Store the old options */
1164         old_sb_flags = sb->s_flags;
1165         old_opts.s_mount_opt = sbi->s_mount_opt;
1166         old_opts.s_resuid = sbi->s_resuid;
1167         old_opts.s_resgid = sbi->s_resgid;
1168
1169         /*
1170          * Allow the "check" option to be passed as a remount option.
1171          */
1172         if (!parse_options (data, sbi)) {
1173                 err = -EINVAL;
1174                 goto restore_opts;
1175         }
1176
1177         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1178                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1179
1180         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1181                                     EXT2_MOUNT_XIP if not */
1182
1183         if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1184                 printk("XIP: Unsupported blocksize\n");
1185                 err = -EINVAL;
1186                 goto restore_opts;
1187         }
1188
1189         es = sbi->s_es;
1190         if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1191             (old_mount_opt & EXT2_MOUNT_XIP)) &&
1192             invalidate_inodes(sb)) {
1193                 ext2_warning(sb, __func__, "refusing change of xip flag "
1194                              "with busy inodes while remounting");
1195                 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1196                 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1197         }
1198         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1199                 return 0;
1200         if (*flags & MS_RDONLY) {
1201                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1202                     !(sbi->s_mount_state & EXT2_VALID_FS))
1203                         return 0;
1204                 /*
1205                  * OK, we are remounting a valid rw partition rdonly, so set
1206                  * the rdonly flag and then mark the partition as valid again.
1207                  */
1208                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1209                 es->s_mtime = cpu_to_le32(get_seconds());
1210         } else {
1211                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1212                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1213                 if (ret) {
1214                         printk("EXT2-fs: %s: couldn't remount RDWR because of "
1215                                "unsupported optional features (%x).\n",
1216                                sb->s_id, le32_to_cpu(ret));
1217                         err = -EROFS;
1218                         goto restore_opts;
1219                 }
1220                 /*
1221                  * Mounting a RDONLY partition read-write, so reread and
1222                  * store the current valid flag.  (It may have been changed
1223                  * by e2fsck since we originally mounted the partition.)
1224                  */
1225                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1226                 if (!ext2_setup_super (sb, es, 0))
1227                         sb->s_flags &= ~MS_RDONLY;
1228         }
1229         ext2_sync_super(sb, es);
1230         return 0;
1231 restore_opts:
1232         sbi->s_mount_opt = old_opts.s_mount_opt;
1233         sbi->s_resuid = old_opts.s_resuid;
1234         sbi->s_resgid = old_opts.s_resgid;
1235         sb->s_flags = old_sb_flags;
1236         return err;
1237 }
1238
1239 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1240 {
1241         struct super_block *sb = dentry->d_sb;
1242         struct ext2_sb_info *sbi = EXT2_SB(sb);
1243         struct ext2_super_block *es = sbi->s_es;
1244         u64 fsid;
1245
1246         if (test_opt (sb, MINIX_DF))
1247                 sbi->s_overhead_last = 0;
1248         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1249                 unsigned long i, overhead = 0;
1250                 smp_rmb();
1251
1252                 /*
1253                  * Compute the overhead (FS structures). This is constant
1254                  * for a given filesystem unless the number of block groups
1255                  * changes so we cache the previous value until it does.
1256                  */
1257
1258                 /*
1259                  * All of the blocks before first_data_block are
1260                  * overhead
1261                  */
1262                 overhead = le32_to_cpu(es->s_first_data_block);
1263
1264                 /*
1265                  * Add the overhead attributed to the superblock and
1266                  * block group descriptors.  If the sparse superblocks
1267                  * feature is turned on, then not all groups have this.
1268                  */
1269                 for (i = 0; i < sbi->s_groups_count; i++)
1270                         overhead += ext2_bg_has_super(sb, i) +
1271                                 ext2_bg_num_gdb(sb, i);
1272
1273                 /*
1274                  * Every block group has an inode bitmap, a block
1275                  * bitmap, and an inode table.
1276                  */
1277                 overhead += (sbi->s_groups_count *
1278                              (2 + sbi->s_itb_per_group));
1279                 sbi->s_overhead_last = overhead;
1280                 smp_wmb();
1281                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1282         }
1283
1284         buf->f_type = EXT2_SUPER_MAGIC;
1285         buf->f_bsize = sb->s_blocksize;
1286         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1287         buf->f_bfree = ext2_count_free_blocks(sb);
1288         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1289         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1290         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1291                 buf->f_bavail = 0;
1292         buf->f_files = le32_to_cpu(es->s_inodes_count);
1293         buf->f_ffree = ext2_count_free_inodes(sb);
1294         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1295         buf->f_namelen = EXT2_NAME_LEN;
1296         fsid = le64_to_cpup((void *)es->s_uuid) ^
1297                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1298         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1299         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1300         return 0;
1301 }
1302
1303 static int ext2_get_sb(struct file_system_type *fs_type,
1304         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1305 {
1306         return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1307 }
1308
1309 #ifdef CONFIG_QUOTA
1310
1311 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1312  * acquiring the locks... As quota files are never truncated and quota code
1313  * itself serializes the operations (and noone else should touch the files)
1314  * we don't have to be afraid of races */
1315 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1316                                size_t len, loff_t off)
1317 {
1318         struct inode *inode = sb_dqopt(sb)->files[type];
1319         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1320         int err = 0;
1321         int offset = off & (sb->s_blocksize - 1);
1322         int tocopy;
1323         size_t toread;
1324         struct buffer_head tmp_bh;
1325         struct buffer_head *bh;
1326         loff_t i_size = i_size_read(inode);
1327
1328         if (off > i_size)
1329                 return 0;
1330         if (off+len > i_size)
1331                 len = i_size-off;
1332         toread = len;
1333         while (toread > 0) {
1334                 tocopy = sb->s_blocksize - offset < toread ?
1335                                 sb->s_blocksize - offset : toread;
1336
1337                 tmp_bh.b_state = 0;
1338                 tmp_bh.b_size = sb->s_blocksize;
1339                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1340                 if (err < 0)
1341                         return err;
1342                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1343                         memset(data, 0, tocopy);
1344                 else {
1345                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1346                         if (!bh)
1347                                 return -EIO;
1348                         memcpy(data, bh->b_data+offset, tocopy);
1349                         brelse(bh);
1350                 }
1351                 offset = 0;
1352                 toread -= tocopy;
1353                 data += tocopy;
1354                 blk++;
1355         }
1356         return len;
1357 }
1358
1359 /* Write to quotafile */
1360 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1361                                 const char *data, size_t len, loff_t off)
1362 {
1363         struct inode *inode = sb_dqopt(sb)->files[type];
1364         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1365         int err = 0;
1366         int offset = off & (sb->s_blocksize - 1);
1367         int tocopy;
1368         size_t towrite = len;
1369         struct buffer_head tmp_bh;
1370         struct buffer_head *bh;
1371
1372         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1373         while (towrite > 0) {
1374                 tocopy = sb->s_blocksize - offset < towrite ?
1375                                 sb->s_blocksize - offset : towrite;
1376
1377                 tmp_bh.b_state = 0;
1378                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1379                 if (err < 0)
1380                         goto out;
1381                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1382                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1383                 else
1384                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1385                 if (!bh) {
1386                         err = -EIO;
1387                         goto out;
1388                 }
1389                 lock_buffer(bh);
1390                 memcpy(bh->b_data+offset, data, tocopy);
1391                 flush_dcache_page(bh->b_page);
1392                 set_buffer_uptodate(bh);
1393                 mark_buffer_dirty(bh);
1394                 unlock_buffer(bh);
1395                 brelse(bh);
1396                 offset = 0;
1397                 towrite -= tocopy;
1398                 data += tocopy;
1399                 blk++;
1400         }
1401 out:
1402         if (len == towrite) {
1403                 mutex_unlock(&inode->i_mutex);
1404                 return err;
1405         }
1406         if (inode->i_size < off+len-towrite)
1407                 i_size_write(inode, off+len-towrite);
1408         inode->i_version++;
1409         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1410         mark_inode_dirty(inode);
1411         mutex_unlock(&inode->i_mutex);
1412         return len - towrite;
1413 }
1414
1415 #endif
1416
1417 static struct file_system_type ext2_fs_type = {
1418         .owner          = THIS_MODULE,
1419         .name           = "ext2",
1420         .get_sb         = ext2_get_sb,
1421         .kill_sb        = kill_block_super,
1422         .fs_flags       = FS_REQUIRES_DEV,
1423 };
1424
1425 static int __init init_ext2_fs(void)
1426 {
1427         int err = init_ext2_xattr();
1428         if (err)
1429                 return err;
1430         err = init_inodecache();
1431         if (err)
1432                 goto out1;
1433         err = register_filesystem(&ext2_fs_type);
1434         if (err)
1435                 goto out;
1436         return 0;
1437 out:
1438         destroy_inodecache();
1439 out1:
1440         exit_ext2_xattr();
1441         return err;
1442 }
1443
1444 static void __exit exit_ext2_fs(void)
1445 {
1446         unregister_filesystem(&ext2_fs_type);
1447         destroy_inodecache();
1448         exit_ext2_xattr();
1449 }
1450
1451 module_init(init_ext2_fs)
1452 module_exit(exit_ext2_fs)