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