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 <asm/uaccess.h>
  35 #include "ext2.h"
  36 #include "xattr.h"
  37 #include "acl.h"
  38 #include "xip.h"
  39
  40 static void ext2_sync_super(struct super_block *sb,
  41                             struct ext2_super_block *es);
  42 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  43 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  44
  45 void ext2_error (struct super_block * sb, const char * function,
  46                  const char * fmt, ...)
  47 {
  48         va_list args;
  49         struct ext2_sb_info *sbi = EXT2_SB(sb);
  50         struct ext2_super_block *es = sbi->s_es;
  51
  52         if (!(sb->s_flags & MS_RDONLY)) {
  53                 sbi->s_mount_state |= EXT2_ERROR_FS;
  54                 es->s_state =
  55                         cpu_to_le16(le16_to_cpu(es->s_state) | 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, __FUNCTION__,
  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         ext2_xattr_put_super(sb);
 118         if (!(sb->s_flags & MS_RDONLY)) {
 119                 struct ext2_super_block *es = sbi->s_es;
 120
 121                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 122                 ext2_sync_super(sb, es);
 123         }
 124         db_count = sbi->s_gdb_count;
 125         for (i = 0; i < db_count; i++)
 126                 if (sbi->s_group_desc[i])
 127                         brelse (sbi->s_group_desc[i]);
 128         kfree(sbi->s_group_desc);
 129         kfree(sbi->s_debts);
 130         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 131         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 132         percpu_counter_destroy(&sbi->s_dirs_counter);
 133         brelse (sbi->s_sbh);
 134         sb->s_fs_info = NULL;
 135         kfree(sbi);
 136
 137         return;
 138 }
 139
 140 static struct kmem_cache * ext2_inode_cachep;
 141
 142 static struct inode *ext2_alloc_inode(struct super_block *sb)
 143 {
 144         struct ext2_inode_info *ei;
 145         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 146         if (!ei)
 147                 return NULL;
 148 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 149         ei->i_acl = EXT2_ACL_NOT_CACHED;
 150         ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 151 #endif
 152         ei->i_block_alloc_info = NULL;
 153         ei->vfs_inode.i_version = 1;
 154         return &ei->vfs_inode;
 155 }
 156
 157 static void ext2_destroy_inode(struct inode *inode)
 158 {
 159         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 160 }
 161
 162 static void init_once(struct kmem_cache * cachep, void *foo)
 163 {
 164         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 165
 166         rwlock_init(&ei->i_meta_lock);
 167 #ifdef CONFIG_EXT2_FS_XATTR
 168         init_rwsem(&ei->xattr_sem);
 169 #endif
 170         mutex_init(&ei->truncate_mutex);
 171         inode_init_once(&ei->vfs_inode);
 172 }
 173
 174 static int init_inodecache(void)
 175 {
 176         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 177                                              sizeof(struct ext2_inode_info),
 178                                              0, (SLAB_RECLAIM_ACCOUNT|
 179                                                 SLAB_MEM_SPREAD),
 180                                              init_once);
 181         if (ext2_inode_cachep == NULL)
 182                 return -ENOMEM;
 183         return 0;
 184 }
 185
 186 static void destroy_inodecache(void)
 187 {
 188         kmem_cache_destroy(ext2_inode_cachep);
 189 }
 190
 191 static void ext2_clear_inode(struct inode *inode)
 192 {
 193         struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
 194 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 195         struct ext2_inode_info *ei = EXT2_I(inode);
 196
 197         if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
 198                 posix_acl_release(ei->i_acl);
 199                 ei->i_acl = EXT2_ACL_NOT_CACHED;
 200         }
 201         if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
 202                 posix_acl_release(ei->i_default_acl);
 203                 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 204         }
 205 #endif
 206         ext2_discard_reservation(inode);
 207         EXT2_I(inode)->i_block_alloc_info = NULL;
 208         if (unlikely(rsv))
 209                 kfree(rsv);
 210 }
 211
 212 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
 213 {
 214         struct super_block *sb = vfs->mnt_sb;
 215         struct ext2_sb_info *sbi = EXT2_SB(sb);
 216         struct ext2_super_block *es = sbi->s_es;
 217         unsigned long def_mount_opts;
 218
 219         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 220
 221         if (sbi->s_sb_block != 1)
 222                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 223         if (test_opt(sb, MINIX_DF))
 224                 seq_puts(seq, ",minixdf");
 225         if (test_opt(sb, GRPID))
 226                 seq_puts(seq, ",grpid");
 227         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 228                 seq_puts(seq, ",nogrpid");
 229         if (sbi->s_resuid != EXT2_DEF_RESUID ||
 230             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 231                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 232         }
 233         if (sbi->s_resgid != EXT2_DEF_RESGID ||
 234             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 235                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 236         }
 237         if (test_opt(sb, ERRORS_CONT)) {
 238                 int def_errors = le16_to_cpu(es->s_errors);
 239
 240                 if (def_errors == EXT2_ERRORS_PANIC ||
 241                     def_errors == EXT2_ERRORS_RO) {
 242                         seq_puts(seq, ",errors=continue");
 243                 }
 244         }
 245         if (test_opt(sb, ERRORS_RO))
 246                 seq_puts(seq, ",errors=remount-ro");
 247         if (test_opt(sb, ERRORS_PANIC))
 248                 seq_puts(seq, ",errors=panic");
 249         if (test_opt(sb, NO_UID32))
 250                 seq_puts(seq, ",nouid32");
 251         if (test_opt(sb, DEBUG))
 252                 seq_puts(seq, ",debug");
 253         if (test_opt(sb, OLDALLOC))
 254                 seq_puts(seq, ",oldalloc");
 255
 256 #ifdef CONFIG_EXT2_FS_XATTR
 257         if (test_opt(sb, XATTR_USER))
 258                 seq_puts(seq, ",user_xattr");
 259         if (!test_opt(sb, XATTR_USER) &&
 260             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 261                 seq_puts(seq, ",nouser_xattr");
 262         }
 263 #endif
 264
 265 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 266         if (test_opt(sb, POSIX_ACL))
 267                 seq_puts(seq, ",acl");
 268         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 269                 seq_puts(seq, ",noacl");
 270 #endif
 271
 272         if (test_opt(sb, NOBH))
 273                 seq_puts(seq, ",nobh");
 274
 275 #if defined(CONFIG_QUOTA)
 276         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 277                 seq_puts(seq, ",usrquota");
 278
 279         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 280                 seq_puts(seq, ",grpquota");
 281 #endif
 282
 283 #if defined(CONFIG_EXT2_FS_XIP)
 284         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 285                 seq_puts(seq, ",xip");
 286 #endif
 287
 288         return 0;
 289 }
 290
 291 #ifdef CONFIG_QUOTA
 292 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 293 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 294 #endif
 295
 296 static const struct super_operations ext2_sops = {
 297         .alloc_inode    = ext2_alloc_inode,
 298         .destroy_inode  = ext2_destroy_inode,
 299         .read_inode     = ext2_read_inode,
 300         .write_inode    = ext2_write_inode,
 301         .delete_inode   = ext2_delete_inode,
 302         .put_super      = ext2_put_super,
 303         .write_super    = ext2_write_super,
 304         .statfs         = ext2_statfs,
 305         .remount_fs     = ext2_remount,
 306         .clear_inode    = ext2_clear_inode,
 307         .show_options   = ext2_show_options,
 308 #ifdef CONFIG_QUOTA
 309         .quota_read     = ext2_quota_read,
 310         .quota_write    = ext2_quota_write,
 311 #endif
 312 };
 313
 314 static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
 315 {
 316         __u32 *objp = vobjp;
 317         unsigned long ino = objp[0];
 318         __u32 generation = objp[1];
 319         struct inode *inode;
 320         struct dentry *result;
 321
 322         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 323                 return ERR_PTR(-ESTALE);
 324         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 325                 return ERR_PTR(-ESTALE);
 326
 327         /* iget isn't really right if the inode is currently unallocated!!
 328          * ext2_read_inode currently does appropriate checks, but
 329          * it might be "neater" to call ext2_get_inode first and check
 330          * if the inode is valid.....
 331          */
 332         inode = iget(sb, ino);
 333         if (inode == NULL)
 334                 return ERR_PTR(-ENOMEM);
 335         if (is_bad_inode(inode) ||
 336             (generation && inode->i_generation != generation)) {
 337                 /* we didn't find the right inode.. */
 338                 iput(inode);
 339                 return ERR_PTR(-ESTALE);
 340         }
 341         /* now to find a dentry.
 342          * If possible, get a well-connected one
 343          */
 344         result = d_alloc_anon(inode);
 345         if (!result) {
 346                 iput(inode);
 347                 return ERR_PTR(-ENOMEM);
 348         }
 349         return result;
 350 }
 351
 352 /* Yes, most of these are left as NULL!!
 353  * A NULL value implies the default, which works with ext2-like file
 354  * systems, but can be improved upon.
 355  * Currently only get_parent is required.
 356  */
 357 static struct export_operations ext2_export_ops = {
 358         .get_parent = ext2_get_parent,
 359         .get_dentry = ext2_get_dentry,
 360 };
 361
 362 static unsigned long get_sb_block(void **data)
 363 {
 364         unsigned long   sb_block;
 365         char            *options = (char *) *data;
 366
 367         if (!options || strncmp(options, "sb=", 3) != 0)
 368                 return 1;       /* Default location */
 369         options += 3;
 370         sb_block = simple_strtoul(options, &options, 0);
 371         if (*options && *options != ',') {
 372                 printk("EXT2-fs: Invalid sb specification: %s\n",
 373                        (char *) *data);
 374                 return 1;
 375         }
 376         if (*options == ',')
 377                 options++;
 378         *data = (void *) options;
 379         return sb_block;
 380 }
 381
 382 enum {
 383         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 384         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 385         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 386         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 387         Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 388         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 389 };
 390
 391 static match_table_t tokens = {
 392         {Opt_bsd_df, "bsddf"},
 393         {Opt_minix_df, "minixdf"},
 394         {Opt_grpid, "grpid"},
 395         {Opt_grpid, "bsdgroups"},
 396         {Opt_nogrpid, "nogrpid"},
 397         {Opt_nogrpid, "sysvgroups"},
 398         {Opt_resgid, "resgid=%u"},
 399         {Opt_resuid, "resuid=%u"},
 400         {Opt_sb, "sb=%u"},
 401         {Opt_err_cont, "errors=continue"},
 402         {Opt_err_panic, "errors=panic"},
 403         {Opt_err_ro, "errors=remount-ro"},
 404         {Opt_nouid32, "nouid32"},
 405         {Opt_nocheck, "check=none"},
 406         {Opt_nocheck, "nocheck"},
 407         {Opt_debug, "debug"},
 408         {Opt_oldalloc, "oldalloc"},
 409         {Opt_orlov, "orlov"},
 410         {Opt_nobh, "nobh"},
 411         {Opt_user_xattr, "user_xattr"},
 412         {Opt_nouser_xattr, "nouser_xattr"},
 413         {Opt_acl, "acl"},
 414         {Opt_noacl, "noacl"},
 415         {Opt_xip, "xip"},
 416         {Opt_grpquota, "grpquota"},
 417         {Opt_ignore, "noquota"},
 418         {Opt_quota, "quota"},
 419         {Opt_usrquota, "usrquota"},
 420         {Opt_reservation, "reservation"},
 421         {Opt_noreservation, "noreservation"},
 422         {Opt_err, NULL}
 423 };
 424
 425 static int parse_options (char * options,
 426                           struct ext2_sb_info *sbi)
 427 {
 428         char * p;
 429         substring_t args[MAX_OPT_ARGS];
 430         int option;
 431
 432         if (!options)
 433                 return 1;
 434
 435         while ((p = strsep (&options, ",")) != NULL) {
 436                 int token;
 437                 if (!*p)
 438                         continue;
 439
 440                 token = match_token(p, tokens, args);
 441                 switch (token) {
 442                 case Opt_bsd_df:
 443                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 444                         break;
 445                 case Opt_minix_df:
 446                         set_opt (sbi->s_mount_opt, MINIX_DF);
 447                         break;
 448                 case Opt_grpid:
 449                         set_opt (sbi->s_mount_opt, GRPID);
 450                         break;
 451                 case Opt_nogrpid:
 452                         clear_opt (sbi->s_mount_opt, GRPID);
 453                         break;
 454                 case Opt_resuid:
 455                         if (match_int(&args[0], &option))
 456                                 return 0;
 457                         sbi->s_resuid = option;
 458                         break;
 459                 case Opt_resgid:
 460                         if (match_int(&args[0], &option))
 461                                 return 0;
 462                         sbi->s_resgid = option;
 463                         break;
 464                 case Opt_sb:
 465                         /* handled by get_sb_block() instead of here */
 466                         /* *sb_block = match_int(&args[0]); */
 467                         break;
 468                 case Opt_err_panic:
 469                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 470                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 471                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 472                         break;
 473                 case Opt_err_ro:
 474                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 475                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 476                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 477                         break;
 478                 case Opt_err_cont:
 479                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 480                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 481                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 482                         break;
 483                 case Opt_nouid32:
 484                         set_opt (sbi->s_mount_opt, NO_UID32);
 485                         break;
 486                 case Opt_nocheck:
 487                         clear_opt (sbi->s_mount_opt, CHECK);
 488                         break;
 489                 case Opt_debug:
 490                         set_opt (sbi->s_mount_opt, DEBUG);
 491                         break;
 492                 case Opt_oldalloc:
 493                         set_opt (sbi->s_mount_opt, OLDALLOC);
 494                         break;
 495                 case Opt_orlov:
 496                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 497                         break;
 498                 case Opt_nobh:
 499                         set_opt (sbi->s_mount_opt, NOBH);
 500                         break;
 501 #ifdef CONFIG_EXT2_FS_XATTR
 502                 case Opt_user_xattr:
 503                         set_opt (sbi->s_mount_opt, XATTR_USER);
 504                         break;
 505                 case Opt_nouser_xattr:
 506                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 507                         break;
 508 #else
 509                 case Opt_user_xattr:
 510                 case Opt_nouser_xattr:
 511                         printk("EXT2 (no)user_xattr options not supported\n");
 512                         break;
 513 #endif
 514 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 515                 case Opt_acl:
 516                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 517                         break;
 518                 case Opt_noacl:
 519                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 520                         break;
 521 #else
 522                 case Opt_acl:
 523                 case Opt_noacl:
 524                         printk("EXT2 (no)acl options not supported\n");
 525                         break;
 526 #endif
 527                 case Opt_xip:
 528 #ifdef CONFIG_EXT2_FS_XIP
 529                         set_opt (sbi->s_mount_opt, XIP);
 530 #else
 531                         printk("EXT2 xip option not supported\n");
 532 #endif
 533                         break;
 534
 535 #if defined(CONFIG_QUOTA)
 536                 case Opt_quota:
 537                 case Opt_usrquota:
 538                         set_opt(sbi->s_mount_opt, USRQUOTA);
 539                         break;
 540
 541                 case Opt_grpquota:
 542                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 543                         break;
 544 #else
 545                 case Opt_quota:
 546                 case Opt_usrquota:
 547                 case Opt_grpquota:
 548                         printk(KERN_ERR
 549                                 "EXT2-fs: quota operations not supported.\n");
 550
 551                         break;
 552 #endif
 553
 554                 case Opt_reservation:
 555                         set_opt(sbi->s_mount_opt, RESERVATION);
 556                         printk("reservations ON\n");
 557                         break;
 558                 case Opt_noreservation:
 559                         clear_opt(sbi->s_mount_opt, RESERVATION);
 560                         printk("reservations OFF\n");
 561                         break;
 562                 case Opt_ignore:
 563                         break;
 564                 default:
 565                         return 0;
 566                 }
 567         }
 568         return 1;
 569 }
 570
 571 static int ext2_setup_super (struct super_block * sb,
 572                               struct ext2_super_block * es,
 573                               int read_only)
 574 {
 575         int res = 0;
 576         struct ext2_sb_info *sbi = EXT2_SB(sb);
 577
 578         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 579                 printk ("EXT2-fs warning: revision level too high, "
 580                         "forcing read-only mode\n");
 581                 res = MS_RDONLY;
 582         }
 583         if (read_only)
 584                 return res;
 585         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 586                 printk ("EXT2-fs warning: mounting unchecked fs, "
 587                         "running e2fsck is recommended\n");
 588         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 589                 printk ("EXT2-fs warning: mounting fs with errors, "
 590                         "running e2fsck is recommended\n");
 591         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 592                  le16_to_cpu(es->s_mnt_count) >=
 593                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 594                 printk ("EXT2-fs warning: maximal mount count reached, "
 595                         "running e2fsck is recommended\n");
 596         else if (le32_to_cpu(es->s_checkinterval) &&
 597                 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 598                 printk ("EXT2-fs warning: checktime reached, "
 599                         "running e2fsck is recommended\n");
 600         if (!le16_to_cpu(es->s_max_mnt_count))
 601                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 602         es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
 603         ext2_write_super(sb);
 604         if (test_opt (sb, DEBUG))
 605                 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
 606                         "bpg=%lu, ipg=%lu, mo=%04lx]\n",
 607                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 608                         sbi->s_frag_size,
 609                         sbi->s_groups_count,
 610                         EXT2_BLOCKS_PER_GROUP(sb),
 611                         EXT2_INODES_PER_GROUP(sb),
 612                         sbi->s_mount_opt);
 613         return res;
 614 }
 615
 616 static int ext2_check_descriptors (struct super_block * sb)
 617 {
 618         int i;
 619         int desc_block = 0;
 620         struct ext2_sb_info *sbi = EXT2_SB(sb);
 621         unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
 622         unsigned long last_block;
 623         struct ext2_group_desc * gdp = NULL;
 624
 625         ext2_debug ("Checking group descriptors");
 626
 627         for (i = 0; i < sbi->s_groups_count; i++)
 628         {
 629                 if (i == sbi->s_groups_count - 1)
 630                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 631                 else
 632                         last_block = first_block +
 633                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 634
 635                 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
 636                         gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
 637                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 638                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 639                 {
 640                         ext2_error (sb, "ext2_check_descriptors",
 641                                     "Block bitmap for group %d"
 642                                     " not in group (block %lu)!",
 643                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 644                         return 0;
 645                 }
 646                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 647                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 648                 {
 649                         ext2_error (sb, "ext2_check_descriptors",
 650                                     "Inode bitmap for group %d"
 651                                     " not in group (block %lu)!",
 652                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 653                         return 0;
 654                 }
 655                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 656                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 657                     last_block)
 658                 {
 659                         ext2_error (sb, "ext2_check_descriptors",
 660                                     "Inode table for group %d"
 661                                     " not in group (block %lu)!",
 662                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 663                         return 0;
 664                 }
 665                 first_block += EXT2_BLOCKS_PER_GROUP(sb);
 666                 gdp++;
 667         }
 668         return 1;
 669 }
 670
 671 /*
 672  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 673  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 674  * We need to be 1 filesystem block less than the 2^32 sector limit.
 675  */
 676 static loff_t ext2_max_size(int bits)
 677 {
 678         loff_t res = EXT2_NDIR_BLOCKS;
 679         /* This constant is calculated to be the largest file size for a
 680          * dense, 4k-blocksize file such that the total number of
 681          * sectors in the file, including data and all indirect blocks,
 682          * does not exceed 2^32. */
 683         const loff_t upper_limit = 0x1ff7fffd000LL;
 684
 685         res += 1LL << (bits-2);
 686         res += 1LL << (2*(bits-2));
 687         res += 1LL << (3*(bits-2));
 688         res <<= bits;
 689         if (res > upper_limit)
 690                 res = upper_limit;
 691         return res;
 692 }
 693
 694 static unsigned long descriptor_loc(struct super_block *sb,
 695                                     unsigned long logic_sb_block,
 696                                     int nr)
 697 {
 698         struct ext2_sb_info *sbi = EXT2_SB(sb);
 699         unsigned long bg, first_data_block, first_meta_bg;
 700         int has_super = 0;
 701
 702         first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
 703         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 704
 705         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 706             nr < first_meta_bg)
 707                 return (logic_sb_block + nr + 1);
 708         bg = sbi->s_desc_per_block * nr;
 709         if (ext2_bg_has_super(sb, bg))
 710                 has_super = 1;
 711         return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
 712 }
 713
 714 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 715 {
 716         struct buffer_head * bh;
 717         struct ext2_sb_info * sbi;
 718         struct ext2_super_block * es;
 719         struct inode *root;
 720         unsigned long block;
 721         unsigned long sb_block = get_sb_block(&data);
 722         unsigned long logic_sb_block;
 723         unsigned long offset = 0;
 724         unsigned long def_mount_opts;
 725         int blocksize = BLOCK_SIZE;
 726         int db_count;
 727         int i, j;
 728         __le32 features;
 729         int err;
 730
 731         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 732         if (!sbi)
 733                 return -ENOMEM;
 734         sb->s_fs_info = sbi;
 735         sbi->s_sb_block = sb_block;
 736
 737         /*
 738          * See what the current blocksize for the device is, and
 739          * use that as the blocksize.  Otherwise (or if the blocksize
 740          * is smaller than the default) use the default.
 741          * This is important for devices that have a hardware
 742          * sectorsize that is larger than the default.
 743          */
 744         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 745         if (!blocksize) {
 746                 printk ("EXT2-fs: unable to set blocksize\n");
 747                 goto failed_sbi;
 748         }
 749
 750         /*
 751          * If the superblock doesn't start on a hardware sector boundary,
 752          * calculate the offset.
 753          */
 754         if (blocksize != BLOCK_SIZE) {
 755                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 756                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 757         } else {
 758                 logic_sb_block = sb_block;
 759         }
 760
 761         if (!(bh = sb_bread(sb, logic_sb_block))) {
 762                 printk ("EXT2-fs: unable to read superblock\n");
 763                 goto failed_sbi;
 764         }
 765         /*
 766          * Note: s_es must be initialized as soon as possible because
 767          *       some ext2 macro-instructions depend on its value
 768          */
 769         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 770         sbi->s_es = es;
 771         sb->s_magic = le16_to_cpu(es->s_magic);
 772
 773         if (sb->s_magic != EXT2_SUPER_MAGIC)
 774                 goto cantfind_ext2;
 775
 776         /* Set defaults before we parse the mount options */
 777         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 778         if (def_mount_opts & EXT2_DEFM_DEBUG)
 779                 set_opt(sbi->s_mount_opt, DEBUG);
 780         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 781                 set_opt(sbi->s_mount_opt, GRPID);
 782         if (def_mount_opts & EXT2_DEFM_UID16)
 783                 set_opt(sbi->s_mount_opt, NO_UID32);
 784 #ifdef CONFIG_EXT2_FS_XATTR
 785         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 786                 set_opt(sbi->s_mount_opt, XATTR_USER);
 787 #endif
 788 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 789         if (def_mount_opts & EXT2_DEFM_ACL)
 790                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 791 #endif
 792
 793         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 794                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 795         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
 796                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 797         else
 798                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 799
 800         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 801         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 802
 803         set_opt(sbi->s_mount_opt, RESERVATION);
 804
 805         if (!parse_options ((char *) data, sbi))
 806                 goto failed_mount;
 807
 808         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 809                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 810                  MS_POSIXACL : 0);
 811
 812         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 813                                     EXT2_MOUNT_XIP if not */
 814
 815         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 816             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 817              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 818              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 819                 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
 820                        "running e2fsck is recommended\n");
 821         /*
 822          * Check feature flags regardless of the revision level, since we
 823          * previously didn't change the revision level when setting the flags,
 824          * so there is a chance incompat flags are set on a rev 0 filesystem.
 825          */
 826         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 827         if (features) {
 828                 printk("EXT2-fs: %s: couldn't mount because of "
 829                        "unsupported optional features (%x).\n",
 830                        sb->s_id, le32_to_cpu(features));
 831                 goto failed_mount;
 832         }
 833         if (!(sb->s_flags & MS_RDONLY) &&
 834             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 835                 printk("EXT2-fs: %s: couldn't mount RDWR because of "
 836                        "unsupported optional features (%x).\n",
 837                        sb->s_id, le32_to_cpu(features));
 838                 goto failed_mount;
 839         }
 840
 841         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 842
 843         if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
 844                                   (sb->s_blocksize != blocksize))) {
 845                 if (!silent)
 846                         printk("XIP: Unsupported blocksize\n");
 847                 goto failed_mount;
 848         }
 849
 850         /* If the blocksize doesn't match, re-read the thing.. */
 851         if (sb->s_blocksize != blocksize) {
 852                 brelse(bh);
 853
 854                 if (!sb_set_blocksize(sb, blocksize)) {
 855                         printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
 856                         goto failed_sbi;
 857                 }
 858
 859                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 860                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 861                 bh = sb_bread(sb, logic_sb_block);
 862                 if(!bh) {
 863                         printk("EXT2-fs: Couldn't read superblock on "
 864                                "2nd try.\n");
 865                         goto failed_sbi;
 866                 }
 867                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 868                 sbi->s_es = es;
 869                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 870                         printk ("EXT2-fs: Magic mismatch, very weird !\n");
 871                         goto failed_mount;
 872                 }
 873         }
 874
 875         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 876
 877         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 878                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 879                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 880         } else {
 881                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 882                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 883                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 884                     !is_power_of_2(sbi->s_inode_size) ||
 885                     (sbi->s_inode_size > blocksize)) {
 886                         printk ("EXT2-fs: unsupported inode size: %d\n",
 887                                 sbi->s_inode_size);
 888                         goto failed_mount;
 889                 }
 890         }
 891
 892         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 893                                    le32_to_cpu(es->s_log_frag_size);
 894         if (sbi->s_frag_size == 0)
 895                 goto cantfind_ext2;
 896         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 897
 898         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 899         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 900         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 901
 902         if (EXT2_INODE_SIZE(sb) == 0)
 903                 goto cantfind_ext2;
 904         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 905         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 906                 goto cantfind_ext2;
 907         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 908                                         sbi->s_inodes_per_block;
 909         sbi->s_desc_per_block = sb->s_blocksize /
 910                                         sizeof (struct ext2_group_desc);
 911         sbi->s_sbh = bh;
 912         sbi->s_mount_state = le16_to_cpu(es->s_state);
 913         sbi->s_addr_per_block_bits =
 914                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 915         sbi->s_desc_per_block_bits =
 916                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
 917
 918         if (sb->s_magic != EXT2_SUPER_MAGIC)
 919                 goto cantfind_ext2;
 920
 921         if (sb->s_blocksize != bh->b_size) {
 922                 if (!silent)
 923                         printk ("VFS: Unsupported blocksize on dev "
 924                                 "%s.\n", sb->s_id);
 925                 goto failed_mount;
 926         }
 927
 928         if (sb->s_blocksize != sbi->s_frag_size) {
 929                 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
 930                         sbi->s_frag_size, sb->s_blocksize);
 931                 goto failed_mount;
 932         }
 933
 934         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 935                 printk ("EXT2-fs: #blocks per group too big: %lu\n",
 936                         sbi->s_blocks_per_group);
 937                 goto failed_mount;
 938         }
 939         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 940                 printk ("EXT2-fs: #fragments per group too big: %lu\n",
 941                         sbi->s_frags_per_group);
 942                 goto failed_mount;
 943         }
 944         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 945                 printk ("EXT2-fs: #inodes per group too big: %lu\n",
 946                         sbi->s_inodes_per_group);
 947                 goto failed_mount;
 948         }
 949
 950         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 951                 goto cantfind_ext2;
 952         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
 953                                 le32_to_cpu(es->s_first_data_block) - 1)
 954                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
 955         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 956                    EXT2_DESC_PER_BLOCK(sb);
 957         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
 958         if (sbi->s_group_desc == NULL) {
 959                 printk ("EXT2-fs: not enough memory\n");
 960                 goto failed_mount;
 961         }
 962         bgl_lock_init(&sbi->s_blockgroup_lock);
 963         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
 964         if (!sbi->s_debts) {
 965                 printk ("EXT2-fs: not enough memory\n");
 966                 goto failed_mount_group_desc;
 967         }
 968         for (i = 0; i < db_count; i++) {
 969                 block = descriptor_loc(sb, logic_sb_block, i);
 970                 sbi->s_group_desc[i] = sb_bread(sb, block);
 971                 if (!sbi->s_group_desc[i]) {
 972                         for (j = 0; j < i; j++)
 973                                 brelse (sbi->s_group_desc[j]);
 974                         printk ("EXT2-fs: unable to read group descriptors\n");
 975                         goto failed_mount_group_desc;
 976                 }
 977         }
 978         if (!ext2_check_descriptors (sb)) {
 979                 printk ("EXT2-fs: group descriptors corrupted!\n");
 980                 goto failed_mount2;
 981         }
 982         sbi->s_gdb_count = db_count;
 983         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 984         spin_lock_init(&sbi->s_next_gen_lock);
 985
 986         /* per fileystem reservation list head & lock */
 987         spin_lock_init(&sbi->s_rsv_window_lock);
 988         sbi->s_rsv_window_root = RB_ROOT;
 989         /*
 990          * Add a single, static dummy reservation to the start of the
 991          * reservation window list --- it gives us a placeholder for
 992          * append-at-start-of-list which makes the allocation logic
 993          * _much_ simpler.
 994          */
 995         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
 996         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
 997         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
 998         sbi->s_rsv_window_head.rsv_goal_size = 0;
 999         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1000
1001         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1002                                 ext2_count_free_blocks(sb));
1003         if (!err) {
1004                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1005                                 ext2_count_free_inodes(sb));
1006         }
1007         if (!err) {
1008                 err = percpu_counter_init(&sbi->s_dirs_counter,
1009                                 ext2_count_dirs(sb));
1010         }
1011         if (err) {
1012                 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1013                 goto failed_mount3;
1014         }
1015         /*
1016          * set up enough so that it can read an inode
1017          */
1018         sb->s_op = &ext2_sops;
1019         sb->s_export_op = &ext2_export_ops;
1020         sb->s_xattr = ext2_xattr_handlers;
1021         root = iget(sb, EXT2_ROOT_INO);
1022         sb->s_root = d_alloc_root(root);
1023         if (!sb->s_root) {
1024                 iput(root);
1025                 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1026                 goto failed_mount3;
1027         }
1028         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1029                 dput(sb->s_root);
1030                 sb->s_root = NULL;
1031                 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1032                 goto failed_mount3;
1033         }
1034         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1035                 ext2_warning(sb, __FUNCTION__,
1036                         "mounting ext3 filesystem as ext2");
1037         ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1038         return 0;
1039
1040 cantfind_ext2:
1041         if (!silent)
1042                 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1043                        sb->s_id);
1044         goto failed_mount;
1045 failed_mount3:
1046         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1047         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1048         percpu_counter_destroy(&sbi->s_dirs_counter);
1049 failed_mount2:
1050         for (i = 0; i < db_count; i++)
1051                 brelse(sbi->s_group_desc[i]);
1052 failed_mount_group_desc:
1053         kfree(sbi->s_group_desc);
1054         kfree(sbi->s_debts);
1055 failed_mount:
1056         brelse(bh);
1057 failed_sbi:
1058         sb->s_fs_info = NULL;
1059         kfree(sbi);
1060         return -EINVAL;
1061 }
1062
1063 static void ext2_commit_super (struct super_block * sb,
1064                                struct ext2_super_block * es)
1065 {
1066         es->s_wtime = cpu_to_le32(get_seconds());
1067         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1068         sb->s_dirt = 0;
1069 }
1070
1071 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1072 {
1073         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1074         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1075         es->s_wtime = cpu_to_le32(get_seconds());
1076         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1077         sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1078         sb->s_dirt = 0;
1079 }
1080
1081 /*
1082  * In the second extended file system, it is not necessary to
1083  * write the super block since we use a mapping of the
1084  * disk super block in a buffer.
1085  *
1086  * However, this function is still used to set the fs valid
1087  * flags to 0.  We need to set this flag to 0 since the fs
1088  * may have been checked while mounted and e2fsck may have
1089  * set s_state to EXT2_VALID_FS after some corrections.
1090  */
1091
1092 void ext2_write_super (struct super_block * sb)
1093 {
1094         struct ext2_super_block * es;
1095         lock_kernel();
1096         if (!(sb->s_flags & MS_RDONLY)) {
1097                 es = EXT2_SB(sb)->s_es;
1098
1099                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
1100                         ext2_debug ("setting valid to 0\n");
1101                         es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
1102                                                   ~EXT2_VALID_FS);
1103                         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1104                         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1105                         es->s_mtime = cpu_to_le32(get_seconds());
1106                         ext2_sync_super(sb, es);
1107                 } else
1108                         ext2_commit_super (sb, es);
1109         }
1110         sb->s_dirt = 0;
1111         unlock_kernel();
1112 }
1113
1114 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1115 {
1116         struct ext2_sb_info * sbi = EXT2_SB(sb);
1117         struct ext2_super_block * es;
1118         unsigned long old_mount_opt = sbi->s_mount_opt;
1119         struct ext2_mount_options old_opts;
1120         unsigned long old_sb_flags;
1121         int err;
1122
1123         /* Store the old options */
1124         old_sb_flags = sb->s_flags;
1125         old_opts.s_mount_opt = sbi->s_mount_opt;
1126         old_opts.s_resuid = sbi->s_resuid;
1127         old_opts.s_resgid = sbi->s_resgid;
1128
1129         /*
1130          * Allow the "check" option to be passed as a remount option.
1131          */
1132         if (!parse_options (data, sbi)) {
1133                 err = -EINVAL;
1134                 goto restore_opts;
1135         }
1136
1137         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1138                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1139
1140         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1141                                     EXT2_MOUNT_XIP if not */
1142
1143         if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1144                 printk("XIP: Unsupported blocksize\n");
1145                 err = -EINVAL;
1146                 goto restore_opts;
1147         }
1148
1149         es = sbi->s_es;
1150         if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1151             (old_mount_opt & EXT2_MOUNT_XIP)) &&
1152             invalidate_inodes(sb))
1153                 ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1154                              "xip remain in cache (no functional problem)");
1155         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1156                 return 0;
1157         if (*flags & MS_RDONLY) {
1158                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1159                     !(sbi->s_mount_state & EXT2_VALID_FS))
1160                         return 0;
1161                 /*
1162                  * OK, we are remounting a valid rw partition rdonly, so set
1163                  * the rdonly flag and then mark the partition as valid again.
1164                  */
1165                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1166                 es->s_mtime = cpu_to_le32(get_seconds());
1167         } else {
1168                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1169                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1170                 if (ret) {
1171                         printk("EXT2-fs: %s: couldn't remount RDWR because of "
1172                                "unsupported optional features (%x).\n",
1173                                sb->s_id, le32_to_cpu(ret));
1174                         err = -EROFS;
1175                         goto restore_opts;
1176                 }
1177                 /*
1178                  * Mounting a RDONLY partition read-write, so reread and
1179                  * store the current valid flag.  (It may have been changed
1180                  * by e2fsck since we originally mounted the partition.)
1181                  */
1182                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1183                 if (!ext2_setup_super (sb, es, 0))
1184                         sb->s_flags &= ~MS_RDONLY;
1185         }
1186         ext2_sync_super(sb, es);
1187         return 0;
1188 restore_opts:
1189         sbi->s_mount_opt = old_opts.s_mount_opt;
1190         sbi->s_resuid = old_opts.s_resuid;
1191         sbi->s_resgid = old_opts.s_resgid;
1192         sb->s_flags = old_sb_flags;
1193         return err;
1194 }
1195
1196 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1197 {
1198         struct super_block *sb = dentry->d_sb;
1199         struct ext2_sb_info *sbi = EXT2_SB(sb);
1200         struct ext2_super_block *es = sbi->s_es;
1201         u64 fsid;
1202
1203         if (test_opt (sb, MINIX_DF))
1204                 sbi->s_overhead_last = 0;
1205         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1206                 unsigned long i, overhead = 0;
1207                 smp_rmb();
1208
1209                 /*
1210                  * Compute the overhead (FS structures). This is constant
1211                  * for a given filesystem unless the number of block groups
1212                  * changes so we cache the previous value until it does.
1213                  */
1214
1215                 /*
1216                  * All of the blocks before first_data_block are
1217                  * overhead
1218                  */
1219                 overhead = le32_to_cpu(es->s_first_data_block);
1220
1221                 /*
1222                  * Add the overhead attributed to the superblock and
1223                  * block group descriptors.  If the sparse superblocks
1224                  * feature is turned on, then not all groups have this.
1225                  */
1226                 for (i = 0; i < sbi->s_groups_count; i++)
1227                         overhead += ext2_bg_has_super(sb, i) +
1228                                 ext2_bg_num_gdb(sb, i);
1229
1230                 /*
1231                  * Every block group has an inode bitmap, a block
1232                  * bitmap, and an inode table.
1233                  */
1234                 overhead += (sbi->s_groups_count *
1235                              (2 + sbi->s_itb_per_group));
1236                 sbi->s_overhead_last = overhead;
1237                 smp_wmb();
1238                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1239         }
1240
1241         buf->f_type = EXT2_SUPER_MAGIC;
1242         buf->f_bsize = sb->s_blocksize;
1243         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1244         buf->f_bfree = ext2_count_free_blocks(sb);
1245         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1246         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1247         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1248                 buf->f_bavail = 0;
1249         buf->f_files = le32_to_cpu(es->s_inodes_count);
1250         buf->f_ffree = ext2_count_free_inodes(sb);
1251         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1252         buf->f_namelen = EXT2_NAME_LEN;
1253         fsid = le64_to_cpup((void *)es->s_uuid) ^
1254                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1255         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1256         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1257         return 0;
1258 }
1259
1260 static int ext2_get_sb(struct file_system_type *fs_type,
1261         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1262 {
1263         return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1264 }
1265
1266 #ifdef CONFIG_QUOTA
1267
1268 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1269  * acquiring the locks... As quota files are never truncated and quota code
1270  * itself serializes the operations (and noone else should touch the files)
1271  * we don't have to be afraid of races */
1272 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1273                                size_t len, loff_t off)
1274 {
1275         struct inode *inode = sb_dqopt(sb)->files[type];
1276         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1277         int err = 0;
1278         int offset = off & (sb->s_blocksize - 1);
1279         int tocopy;
1280         size_t toread;
1281         struct buffer_head tmp_bh;
1282         struct buffer_head *bh;
1283         loff_t i_size = i_size_read(inode);
1284
1285         if (off > i_size)
1286                 return 0;
1287         if (off+len > i_size)
1288                 len = i_size-off;
1289         toread = len;
1290         while (toread > 0) {
1291                 tocopy = sb->s_blocksize - offset < toread ?
1292                                 sb->s_blocksize - offset : toread;
1293
1294                 tmp_bh.b_state = 0;
1295                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1296                 if (err < 0)
1297                         return err;
1298                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1299                         memset(data, 0, tocopy);
1300                 else {
1301                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1302                         if (!bh)
1303                                 return -EIO;
1304                         memcpy(data, bh->b_data+offset, tocopy);
1305                         brelse(bh);
1306                 }
1307                 offset = 0;
1308                 toread -= tocopy;
1309                 data += tocopy;
1310                 blk++;
1311         }
1312         return len;
1313 }
1314
1315 /* Write to quotafile */
1316 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1317                                 const char *data, size_t len, loff_t off)
1318 {
1319         struct inode *inode = sb_dqopt(sb)->files[type];
1320         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1321         int err = 0;
1322         int offset = off & (sb->s_blocksize - 1);
1323         int tocopy;
1324         size_t towrite = len;
1325         struct buffer_head tmp_bh;
1326         struct buffer_head *bh;
1327
1328         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1329         while (towrite > 0) {
1330                 tocopy = sb->s_blocksize - offset < towrite ?
1331                                 sb->s_blocksize - offset : towrite;
1332
1333                 tmp_bh.b_state = 0;
1334                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1335                 if (err < 0)
1336                         goto out;
1337                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1338                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1339                 else
1340                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1341                 if (!bh) {
1342                         err = -EIO;
1343                         goto out;
1344                 }
1345                 lock_buffer(bh);
1346                 memcpy(bh->b_data+offset, data, tocopy);
1347                 flush_dcache_page(bh->b_page);
1348                 set_buffer_uptodate(bh);
1349                 mark_buffer_dirty(bh);
1350                 unlock_buffer(bh);
1351                 brelse(bh);
1352                 offset = 0;
1353                 towrite -= tocopy;
1354                 data += tocopy;
1355                 blk++;
1356         }
1357 out:
1358         if (len == towrite)
1359                 return err;
1360         if (inode->i_size < off+len-towrite)
1361                 i_size_write(inode, off+len-towrite);
1362         inode->i_version++;
1363         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1364         mark_inode_dirty(inode);
1365         mutex_unlock(&inode->i_mutex);
1366         return len - towrite;
1367 }
1368
1369 #endif
1370
1371 static struct file_system_type ext2_fs_type = {
1372         .owner          = THIS_MODULE,
1373         .name           = "ext2",
1374         .get_sb         = ext2_get_sb,
1375         .kill_sb        = kill_block_super,
1376         .fs_flags       = FS_REQUIRES_DEV,
1377 };
1378
1379 static int __init init_ext2_fs(void)
1380 {
1381         int err = init_ext2_xattr();
1382         if (err)
1383                 return err;
1384         err = init_inodecache();
1385         if (err)
1386                 goto out1;
1387         err = register_filesystem(&ext2_fs_type);
1388         if (err)
1389                 goto out;
1390         return 0;
1391 out:
1392         destroy_inodecache();
1393 out1:
1394         exit_ext2_xattr();
1395         return err;
1396 }
1397
1398 static void __exit exit_ext2_fs(void)
1399 {
1400         unregister_filesystem(&ext2_fs_type);
1401         destroy_inodecache();
1402         exit_ext2_xattr();
1403 }
1404
1405 module_init(init_ext2_fs)
1406 module_exit(exit_ext2_fs)