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/vfs.h>
  30 #include <linux/seq_file.h>
  31 #include <linux/mount.h>
  32 #include <linux/log2.h>
  33 #include <linux/quotaops.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, int wait);
  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 static int ext2_sync_fs(struct super_block *sb, int wait);
  45 static int ext2_freeze(struct super_block *sb);
  46 static int ext2_unfreeze(struct super_block *sb);
  47
  48 void ext2_error(struct super_block *sb, const char *function,
  49                 const char *fmt, ...)
  50 {
  51         struct va_format vaf;
  52         va_list args;
  53         struct ext2_sb_info *sbi = EXT2_SB(sb);
  54         struct ext2_super_block *es = sbi->s_es;
  55
  56         if (!(sb->s_flags & MS_RDONLY)) {
  57                 spin_lock(&sbi->s_lock);
  58                 sbi->s_mount_state |= EXT2_ERROR_FS;
  59                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  60                 spin_unlock(&sbi->s_lock);
  61                 ext2_sync_super(sb, es, 1);
  62         }
  63
  64         va_start(args, fmt);
  65
  66         vaf.fmt = fmt;
  67         vaf.va = &args;
  68
  69         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  70                sb->s_id, function, &vaf);
  71
  72         va_end(args);
  73
  74         if (test_opt(sb, ERRORS_PANIC))
  75                 panic("EXT2-fs: panic from previous error\n");
  76         if (test_opt(sb, ERRORS_RO)) {
  77                 ext2_msg(sb, KERN_CRIT,
  78                              "error: remounting filesystem read-only");
  79                 sb->s_flags |= MS_RDONLY;
  80         }
  81 }
  82
  83 void ext2_msg(struct super_block *sb, const char *prefix,
  84                 const char *fmt, ...)
  85 {
  86         struct va_format vaf;
  87         va_list args;
  88
  89         va_start(args, fmt);
  90
  91         vaf.fmt = fmt;
  92         vaf.va = &args;
  93
  94         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  95
  96         va_end(args);
  97 }
  98
  99 /*
 100  * This must be called with sbi->s_lock held.
 101  */
 102 void ext2_update_dynamic_rev(struct super_block *sb)
 103 {
 104         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 105
 106         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 107                 return;
 108
 109         ext2_msg(sb, KERN_WARNING,
 110                      "warning: updating to rev %d because of "
 111                      "new feature flag, running e2fsck is recommended",
 112                      EXT2_DYNAMIC_REV);
 113
 114         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 115         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 116         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 117         /* leave es->s_feature_*compat flags alone */
 118         /* es->s_uuid will be set by e2fsck if empty */
 119
 120         /*
 121          * The rest of the superblock fields should be zero, and if not it
 122          * means they are likely already in use, so leave them alone.  We
 123          * can leave it up to e2fsck to clean up any inconsistencies there.
 124          */
 125 }
 126
 127 static void ext2_put_super (struct super_block * sb)
 128 {
 129         int db_count;
 130         int i;
 131         struct ext2_sb_info *sbi = EXT2_SB(sb);
 132
 133         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 134
 135         ext2_xattr_put_super(sb);
 136         if (!(sb->s_flags & MS_RDONLY)) {
 137                 struct ext2_super_block *es = sbi->s_es;
 138
 139                 spin_lock(&sbi->s_lock);
 140                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 141                 spin_unlock(&sbi->s_lock);
 142                 ext2_sync_super(sb, es, 1);
 143         }
 144         db_count = sbi->s_gdb_count;
 145         for (i = 0; i < db_count; i++)
 146                 if (sbi->s_group_desc[i])
 147                         brelse (sbi->s_group_desc[i]);
 148         kfree(sbi->s_group_desc);
 149         kfree(sbi->s_debts);
 150         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 151         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 152         percpu_counter_destroy(&sbi->s_dirs_counter);
 153         brelse (sbi->s_sbh);
 154         sb->s_fs_info = NULL;
 155         kfree(sbi->s_blockgroup_lock);
 156         kfree(sbi);
 157 }
 158
 159 static struct kmem_cache * ext2_inode_cachep;
 160
 161 static struct inode *ext2_alloc_inode(struct super_block *sb)
 162 {
 163         struct ext2_inode_info *ei;
 164         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 165         if (!ei)
 166                 return NULL;
 167         ei->i_block_alloc_info = NULL;
 168         ei->vfs_inode.i_version = 1;
 169         return &ei->vfs_inode;
 170 }
 171
 172 static void ext2_i_callback(struct rcu_head *head)
 173 {
 174         struct inode *inode = container_of(head, struct inode, i_rcu);
 175         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 176 }
 177
 178 static void ext2_destroy_inode(struct inode *inode)
 179 {
 180         call_rcu(&inode->i_rcu, ext2_i_callback);
 181 }
 182
 183 static void init_once(void *foo)
 184 {
 185         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 186
 187         rwlock_init(&ei->i_meta_lock);
 188 #ifdef CONFIG_EXT2_FS_XATTR
 189         init_rwsem(&ei->xattr_sem);
 190 #endif
 191         mutex_init(&ei->truncate_mutex);
 192         inode_init_once(&ei->vfs_inode);
 193 }
 194
 195 static int __init init_inodecache(void)
 196 {
 197         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 198                                              sizeof(struct ext2_inode_info),
 199                                              0, (SLAB_RECLAIM_ACCOUNT|
 200                                                 SLAB_MEM_SPREAD),
 201                                              init_once);
 202         if (ext2_inode_cachep == NULL)
 203                 return -ENOMEM;
 204         return 0;
 205 }
 206
 207 static void destroy_inodecache(void)
 208 {
 209         /*
 210          * Make sure all delayed rcu free inodes are flushed before we
 211          * destroy cache.
 212          */
 213         rcu_barrier();
 214         kmem_cache_destroy(ext2_inode_cachep);
 215 }
 216
 217 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 218 {
 219         struct super_block *sb = root->d_sb;
 220         struct ext2_sb_info *sbi = EXT2_SB(sb);
 221         struct ext2_super_block *es = sbi->s_es;
 222         unsigned long def_mount_opts;
 223
 224         spin_lock(&sbi->s_lock);
 225         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 226
 227         if (sbi->s_sb_block != 1)
 228                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 229         if (test_opt(sb, MINIX_DF))
 230                 seq_puts(seq, ",minixdf");
 231         if (test_opt(sb, GRPID))
 232                 seq_puts(seq, ",grpid");
 233         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 234                 seq_puts(seq, ",nogrpid");
 235         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 236             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 237                 seq_printf(seq, ",resuid=%u",
 238                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 239         }
 240         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 241             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 242                 seq_printf(seq, ",resgid=%u",
 243                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 244         }
 245         if (test_opt(sb, ERRORS_RO)) {
 246                 int def_errors = le16_to_cpu(es->s_errors);
 247
 248                 if (def_errors == EXT2_ERRORS_PANIC ||
 249                     def_errors == EXT2_ERRORS_CONTINUE) {
 250                         seq_puts(seq, ",errors=remount-ro");
 251                 }
 252         }
 253         if (test_opt(sb, ERRORS_CONT))
 254                 seq_puts(seq, ",errors=continue");
 255         if (test_opt(sb, ERRORS_PANIC))
 256                 seq_puts(seq, ",errors=panic");
 257         if (test_opt(sb, NO_UID32))
 258                 seq_puts(seq, ",nouid32");
 259         if (test_opt(sb, DEBUG))
 260                 seq_puts(seq, ",debug");
 261         if (test_opt(sb, OLDALLOC))
 262                 seq_puts(seq, ",oldalloc");
 263
 264 #ifdef CONFIG_EXT2_FS_XATTR
 265         if (test_opt(sb, XATTR_USER))
 266                 seq_puts(seq, ",user_xattr");
 267         if (!test_opt(sb, XATTR_USER) &&
 268             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 269                 seq_puts(seq, ",nouser_xattr");
 270         }
 271 #endif
 272
 273 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 274         if (test_opt(sb, POSIX_ACL))
 275                 seq_puts(seq, ",acl");
 276         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 277                 seq_puts(seq, ",noacl");
 278 #endif
 279
 280         if (test_opt(sb, NOBH))
 281                 seq_puts(seq, ",nobh");
 282
 283 #if defined(CONFIG_QUOTA)
 284         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 285                 seq_puts(seq, ",usrquota");
 286
 287         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 288                 seq_puts(seq, ",grpquota");
 289 #endif
 290
 291 #if defined(CONFIG_EXT2_FS_XIP)
 292         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 293                 seq_puts(seq, ",xip");
 294 #endif
 295
 296         if (!test_opt(sb, RESERVATION))
 297                 seq_puts(seq, ",noreservation");
 298
 299         spin_unlock(&sbi->s_lock);
 300         return 0;
 301 }
 302
 303 #ifdef CONFIG_QUOTA
 304 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 305 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 306 #endif
 307
 308 static const struct super_operations ext2_sops = {
 309         .alloc_inode    = ext2_alloc_inode,
 310         .destroy_inode  = ext2_destroy_inode,
 311         .write_inode    = ext2_write_inode,
 312         .evict_inode    = ext2_evict_inode,
 313         .put_super      = ext2_put_super,
 314         .sync_fs        = ext2_sync_fs,
 315         .freeze_fs      = ext2_freeze,
 316         .unfreeze_fs    = ext2_unfreeze,
 317         .statfs         = ext2_statfs,
 318         .remount_fs     = ext2_remount,
 319         .show_options   = ext2_show_options,
 320 #ifdef CONFIG_QUOTA
 321         .quota_read     = ext2_quota_read,
 322         .quota_write    = ext2_quota_write,
 323 #endif
 324 };
 325
 326 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 327                 u64 ino, u32 generation)
 328 {
 329         struct inode *inode;
 330
 331         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 332                 return ERR_PTR(-ESTALE);
 333         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 334                 return ERR_PTR(-ESTALE);
 335
 336         /*
 337          * ext2_iget isn't quite right if the inode is currently unallocated!
 338          * However ext2_iget currently does appropriate checks to handle stale
 339          * inodes so everything is OK.
 340          */
 341         inode = ext2_iget(sb, ino);
 342         if (IS_ERR(inode))
 343                 return ERR_CAST(inode);
 344         if (generation && inode->i_generation != generation) {
 345                 /* we didn't find the right inode.. */
 346                 iput(inode);
 347                 return ERR_PTR(-ESTALE);
 348         }
 349         return inode;
 350 }
 351
 352 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 353                 int fh_len, int fh_type)
 354 {
 355         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 356                                     ext2_nfs_get_inode);
 357 }
 358
 359 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 360                 int fh_len, int fh_type)
 361 {
 362         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 363                                     ext2_nfs_get_inode);
 364 }
 365
 366 static const struct export_operations ext2_export_ops = {
 367         .fh_to_dentry = ext2_fh_to_dentry,
 368         .fh_to_parent = ext2_fh_to_parent,
 369         .get_parent = ext2_get_parent,
 370 };
 371
 372 static unsigned long get_sb_block(void **data)
 373 {
 374         unsigned long   sb_block;
 375         char            *options = (char *) *data;
 376
 377         if (!options || strncmp(options, "sb=", 3) != 0)
 378                 return 1;       /* Default location */
 379         options += 3;
 380         sb_block = simple_strtoul(options, &options, 0);
 381         if (*options && *options != ',') {
 382                 printk("EXT2-fs: Invalid sb specification: %s\n",
 383                        (char *) *data);
 384                 return 1;
 385         }
 386         if (*options == ',')
 387                 options++;
 388         *data = (void *) options;
 389         return sb_block;
 390 }
 391
 392 enum {
 393         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 394         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 395         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 396         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 397         Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 398         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 399 };
 400
 401 static const match_table_t tokens = {
 402         {Opt_bsd_df, "bsddf"},
 403         {Opt_minix_df, "minixdf"},
 404         {Opt_grpid, "grpid"},
 405         {Opt_grpid, "bsdgroups"},
 406         {Opt_nogrpid, "nogrpid"},
 407         {Opt_nogrpid, "sysvgroups"},
 408         {Opt_resgid, "resgid=%u"},
 409         {Opt_resuid, "resuid=%u"},
 410         {Opt_sb, "sb=%u"},
 411         {Opt_err_cont, "errors=continue"},
 412         {Opt_err_panic, "errors=panic"},
 413         {Opt_err_ro, "errors=remount-ro"},
 414         {Opt_nouid32, "nouid32"},
 415         {Opt_nocheck, "check=none"},
 416         {Opt_nocheck, "nocheck"},
 417         {Opt_debug, "debug"},
 418         {Opt_oldalloc, "oldalloc"},
 419         {Opt_orlov, "orlov"},
 420         {Opt_nobh, "nobh"},
 421         {Opt_user_xattr, "user_xattr"},
 422         {Opt_nouser_xattr, "nouser_xattr"},
 423         {Opt_acl, "acl"},
 424         {Opt_noacl, "noacl"},
 425         {Opt_xip, "xip"},
 426         {Opt_grpquota, "grpquota"},
 427         {Opt_ignore, "noquota"},
 428         {Opt_quota, "quota"},
 429         {Opt_usrquota, "usrquota"},
 430         {Opt_reservation, "reservation"},
 431         {Opt_noreservation, "noreservation"},
 432         {Opt_err, NULL}
 433 };
 434
 435 static int parse_options(char *options, struct super_block *sb)
 436 {
 437         char *p;
 438         struct ext2_sb_info *sbi = EXT2_SB(sb);
 439         substring_t args[MAX_OPT_ARGS];
 440         int option;
 441         kuid_t uid;
 442         kgid_t gid;
 443
 444         if (!options)
 445                 return 1;
 446
 447         while ((p = strsep (&options, ",")) != NULL) {
 448                 int token;
 449                 if (!*p)
 450                         continue;
 451
 452                 token = match_token(p, tokens, args);
 453                 switch (token) {
 454                 case Opt_bsd_df:
 455                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 456                         break;
 457                 case Opt_minix_df:
 458                         set_opt (sbi->s_mount_opt, MINIX_DF);
 459                         break;
 460                 case Opt_grpid:
 461                         set_opt (sbi->s_mount_opt, GRPID);
 462                         break;
 463                 case Opt_nogrpid:
 464                         clear_opt (sbi->s_mount_opt, GRPID);
 465                         break;
 466                 case Opt_resuid:
 467                         if (match_int(&args[0], &option))
 468                                 return 0;
 469                         uid = make_kuid(current_user_ns(), option);
 470                         if (!uid_valid(uid)) {
 471                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 472                                 return 0;
 473
 474                         }
 475                         sbi->s_resuid = uid;
 476                         break;
 477                 case Opt_resgid:
 478                         if (match_int(&args[0], &option))
 479                                 return 0;
 480                         gid = make_kgid(current_user_ns(), option);
 481                         if (!gid_valid(gid)) {
 482                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 483                                 return 0;
 484                         }
 485                         sbi->s_resgid = gid;
 486                         break;
 487                 case Opt_sb:
 488                         /* handled by get_sb_block() instead of here */
 489                         /* *sb_block = match_int(&args[0]); */
 490                         break;
 491                 case Opt_err_panic:
 492                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 493                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 494                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 495                         break;
 496                 case Opt_err_ro:
 497                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 498                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 499                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 500                         break;
 501                 case Opt_err_cont:
 502                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 503                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 504                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 505                         break;
 506                 case Opt_nouid32:
 507                         set_opt (sbi->s_mount_opt, NO_UID32);
 508                         break;
 509                 case Opt_nocheck:
 510                         clear_opt (sbi->s_mount_opt, CHECK);
 511                         break;
 512                 case Opt_debug:
 513                         set_opt (sbi->s_mount_opt, DEBUG);
 514                         break;
 515                 case Opt_oldalloc:
 516                         set_opt (sbi->s_mount_opt, OLDALLOC);
 517                         break;
 518                 case Opt_orlov:
 519                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 520                         break;
 521                 case Opt_nobh:
 522                         set_opt (sbi->s_mount_opt, NOBH);
 523                         break;
 524 #ifdef CONFIG_EXT2_FS_XATTR
 525                 case Opt_user_xattr:
 526                         set_opt (sbi->s_mount_opt, XATTR_USER);
 527                         break;
 528                 case Opt_nouser_xattr:
 529                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 530                         break;
 531 #else
 532                 case Opt_user_xattr:
 533                 case Opt_nouser_xattr:
 534                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 535                                 "not supported");
 536                         break;
 537 #endif
 538 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 539                 case Opt_acl:
 540                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 541                         break;
 542                 case Opt_noacl:
 543                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 544                         break;
 545 #else
 546                 case Opt_acl:
 547                 case Opt_noacl:
 548                         ext2_msg(sb, KERN_INFO,
 549                                 "(no)acl options not supported");
 550                         break;
 551 #endif
 552                 case Opt_xip:
 553 #ifdef CONFIG_EXT2_FS_XIP
 554                         set_opt (sbi->s_mount_opt, XIP);
 555 #else
 556                         ext2_msg(sb, KERN_INFO, "xip option not supported");
 557 #endif
 558                         break;
 559
 560 #if defined(CONFIG_QUOTA)
 561                 case Opt_quota:
 562                 case Opt_usrquota:
 563                         set_opt(sbi->s_mount_opt, USRQUOTA);
 564                         break;
 565
 566                 case Opt_grpquota:
 567                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 568                         break;
 569 #else
 570                 case Opt_quota:
 571                 case Opt_usrquota:
 572                 case Opt_grpquota:
 573                         ext2_msg(sb, KERN_INFO,
 574                                 "quota operations not supported");
 575                         break;
 576 #endif
 577
 578                 case Opt_reservation:
 579                         set_opt(sbi->s_mount_opt, RESERVATION);
 580                         ext2_msg(sb, KERN_INFO, "reservations ON");
 581                         break;
 582                 case Opt_noreservation:
 583                         clear_opt(sbi->s_mount_opt, RESERVATION);
 584                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 585                         break;
 586                 case Opt_ignore:
 587                         break;
 588                 default:
 589                         return 0;
 590                 }
 591         }
 592         return 1;
 593 }
 594
 595 static int ext2_setup_super (struct super_block * sb,
 596                               struct ext2_super_block * es,
 597                               int read_only)
 598 {
 599         int res = 0;
 600         struct ext2_sb_info *sbi = EXT2_SB(sb);
 601
 602         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 603                 ext2_msg(sb, KERN_ERR,
 604                         "error: revision level too high, "
 605                         "forcing read-only mode");
 606                 res = MS_RDONLY;
 607         }
 608         if (read_only)
 609                 return res;
 610         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 611                 ext2_msg(sb, KERN_WARNING,
 612                         "warning: mounting unchecked fs, "
 613                         "running e2fsck is recommended");
 614         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 615                 ext2_msg(sb, KERN_WARNING,
 616                         "warning: mounting fs with errors, "
 617                         "running e2fsck is recommended");
 618         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 619                  le16_to_cpu(es->s_mnt_count) >=
 620                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 621                 ext2_msg(sb, KERN_WARNING,
 622                         "warning: maximal mount count reached, "
 623                         "running e2fsck is recommended");
 624         else if (le32_to_cpu(es->s_checkinterval) &&
 625                 (le32_to_cpu(es->s_lastcheck) +
 626                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 627                 ext2_msg(sb, KERN_WARNING,
 628                         "warning: checktime reached, "
 629                         "running e2fsck is recommended");
 630         if (!le16_to_cpu(es->s_max_mnt_count))
 631                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 632         le16_add_cpu(&es->s_mnt_count, 1);
 633         if (test_opt (sb, DEBUG))
 634                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 635                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 636                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 637                         sbi->s_frag_size,
 638                         sbi->s_groups_count,
 639                         EXT2_BLOCKS_PER_GROUP(sb),
 640                         EXT2_INODES_PER_GROUP(sb),
 641                         sbi->s_mount_opt);
 642         return res;
 643 }
 644
 645 static int ext2_check_descriptors(struct super_block *sb)
 646 {
 647         int i;
 648         struct ext2_sb_info *sbi = EXT2_SB(sb);
 649
 650         ext2_debug ("Checking group descriptors");
 651
 652         for (i = 0; i < sbi->s_groups_count; i++) {
 653                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 654                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 655                 ext2_fsblk_t last_block;
 656
 657                 if (i == sbi->s_groups_count - 1)
 658                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 659                 else
 660                         last_block = first_block +
 661                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 662
 663                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 664                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 665                 {
 666                         ext2_error (sb, "ext2_check_descriptors",
 667                                     "Block bitmap for group %d"
 668                                     " not in group (block %lu)!",
 669                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 670                         return 0;
 671                 }
 672                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 673                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 674                 {
 675                         ext2_error (sb, "ext2_check_descriptors",
 676                                     "Inode bitmap for group %d"
 677                                     " not in group (block %lu)!",
 678                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 679                         return 0;
 680                 }
 681                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 682                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 683                     last_block)
 684                 {
 685                         ext2_error (sb, "ext2_check_descriptors",
 686                                     "Inode table for group %d"
 687                                     " not in group (block %lu)!",
 688                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 689                         return 0;
 690                 }
 691         }
 692         return 1;
 693 }
 694
 695 /*
 696  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 697  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 698  * We need to be 1 filesystem block less than the 2^32 sector limit.
 699  */
 700 static loff_t ext2_max_size(int bits)
 701 {
 702         loff_t res = EXT2_NDIR_BLOCKS;
 703         int meta_blocks;
 704         loff_t upper_limit;
 705
 706         /* This is calculated to be the largest file size for a
 707          * dense, file such that the total number of
 708          * sectors in the file, including data and all indirect blocks,
 709          * does not exceed 2^32 -1
 710          * __u32 i_blocks representing the total number of
 711          * 512 bytes blocks of the file
 712          */
 713         upper_limit = (1LL << 32) - 1;
 714
 715         /* total blocks in file system block size */
 716         upper_limit >>= (bits - 9);
 717
 718
 719         /* indirect blocks */
 720         meta_blocks = 1;
 721         /* double indirect blocks */
 722         meta_blocks += 1 + (1LL << (bits-2));
 723         /* tripple indirect blocks */
 724         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 725
 726         upper_limit -= meta_blocks;
 727         upper_limit <<= bits;
 728
 729         res += 1LL << (bits-2);
 730         res += 1LL << (2*(bits-2));
 731         res += 1LL << (3*(bits-2));
 732         res <<= bits;
 733         if (res > upper_limit)
 734                 res = upper_limit;
 735
 736         if (res > MAX_LFS_FILESIZE)
 737                 res = MAX_LFS_FILESIZE;
 738
 739         return res;
 740 }
 741
 742 static unsigned long descriptor_loc(struct super_block *sb,
 743                                     unsigned long logic_sb_block,
 744                                     int nr)
 745 {
 746         struct ext2_sb_info *sbi = EXT2_SB(sb);
 747         unsigned long bg, first_meta_bg;
 748         int has_super = 0;
 749
 750         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 751
 752         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 753             nr < first_meta_bg)
 754                 return (logic_sb_block + nr + 1);
 755         bg = sbi->s_desc_per_block * nr;
 756         if (ext2_bg_has_super(sb, bg))
 757                 has_super = 1;
 758
 759         return ext2_group_first_block_no(sb, bg) + has_super;
 760 }
 761
 762 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 763 {
 764         struct buffer_head * bh;
 765         struct ext2_sb_info * sbi;
 766         struct ext2_super_block * es;
 767         struct inode *root;
 768         unsigned long block;
 769         unsigned long sb_block = get_sb_block(&data);
 770         unsigned long logic_sb_block;
 771         unsigned long offset = 0;
 772         unsigned long def_mount_opts;
 773         long ret = -EINVAL;
 774         int blocksize = BLOCK_SIZE;
 775         int db_count;
 776         int i, j;
 777         __le32 features;
 778         int err;
 779
 780         err = -ENOMEM;
 781         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 782         if (!sbi)
 783                 goto failed;
 784
 785         sbi->s_blockgroup_lock =
 786                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 787         if (!sbi->s_blockgroup_lock) {
 788                 kfree(sbi);
 789                 goto failed;
 790         }
 791         sb->s_fs_info = sbi;
 792         sbi->s_sb_block = sb_block;
 793
 794         spin_lock_init(&sbi->s_lock);
 795
 796         /*
 797          * See what the current blocksize for the device is, and
 798          * use that as the blocksize.  Otherwise (or if the blocksize
 799          * is smaller than the default) use the default.
 800          * This is important for devices that have a hardware
 801          * sectorsize that is larger than the default.
 802          */
 803         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 804         if (!blocksize) {
 805                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 806                 goto failed_sbi;
 807         }
 808
 809         /*
 810          * If the superblock doesn't start on a hardware sector boundary,
 811          * calculate the offset.
 812          */
 813         if (blocksize != BLOCK_SIZE) {
 814                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 815                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 816         } else {
 817                 logic_sb_block = sb_block;
 818         }
 819
 820         if (!(bh = sb_bread(sb, logic_sb_block))) {
 821                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 822                 goto failed_sbi;
 823         }
 824         /*
 825          * Note: s_es must be initialized as soon as possible because
 826          *       some ext2 macro-instructions depend on its value
 827          */
 828         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 829         sbi->s_es = es;
 830         sb->s_magic = le16_to_cpu(es->s_magic);
 831
 832         if (sb->s_magic != EXT2_SUPER_MAGIC)
 833                 goto cantfind_ext2;
 834
 835         /* Set defaults before we parse the mount options */
 836         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 837         if (def_mount_opts & EXT2_DEFM_DEBUG)
 838                 set_opt(sbi->s_mount_opt, DEBUG);
 839         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 840                 set_opt(sbi->s_mount_opt, GRPID);
 841         if (def_mount_opts & EXT2_DEFM_UID16)
 842                 set_opt(sbi->s_mount_opt, NO_UID32);
 843 #ifdef CONFIG_EXT2_FS_XATTR
 844         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 845                 set_opt(sbi->s_mount_opt, XATTR_USER);
 846 #endif
 847 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 848         if (def_mount_opts & EXT2_DEFM_ACL)
 849                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 850 #endif
 851
 852         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 853                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 854         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 855                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 856         else
 857                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 858
 859         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 860         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 861
 862         set_opt(sbi->s_mount_opt, RESERVATION);
 863
 864         if (!parse_options((char *) data, sb))
 865                 goto failed_mount;
 866
 867         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 868                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 869                  MS_POSIXACL : 0);
 870
 871         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 872                                     EXT2_MOUNT_XIP if not */
 873
 874         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 875             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 876              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 877              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 878                 ext2_msg(sb, KERN_WARNING,
 879                         "warning: feature flags set on rev 0 fs, "
 880                         "running e2fsck is recommended");
 881         /*
 882          * Check feature flags regardless of the revision level, since we
 883          * previously didn't change the revision level when setting the flags,
 884          * so there is a chance incompat flags are set on a rev 0 filesystem.
 885          */
 886         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 887         if (features) {
 888                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 889                        "unsupported optional features (%x)",
 890                         le32_to_cpu(features));
 891                 goto failed_mount;
 892         }
 893         if (!(sb->s_flags & MS_RDONLY) &&
 894             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 895                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 896                        "unsupported optional features (%x)",
 897                        le32_to_cpu(features));
 898                 goto failed_mount;
 899         }
 900
 901         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 902
 903         if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
 904                 if (!silent)
 905                         ext2_msg(sb, KERN_ERR,
 906                                 "error: unsupported blocksize for xip");
 907                 goto failed_mount;
 908         }
 909
 910         /* If the blocksize doesn't match, re-read the thing.. */
 911         if (sb->s_blocksize != blocksize) {
 912                 brelse(bh);
 913
 914                 if (!sb_set_blocksize(sb, blocksize)) {
 915                         ext2_msg(sb, KERN_ERR,
 916                                 "error: bad blocksize %d", blocksize);
 917                         goto failed_sbi;
 918                 }
 919
 920                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 921                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 922                 bh = sb_bread(sb, logic_sb_block);
 923                 if(!bh) {
 924                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 925                                 "superblock on 2nd try");
 926                         goto failed_sbi;
 927                 }
 928                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 929                 sbi->s_es = es;
 930                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 931                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 932                         goto failed_mount;
 933                 }
 934         }
 935
 936         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 937         sb->s_max_links = EXT2_LINK_MAX;
 938
 939         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 940                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 941                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 942         } else {
 943                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 944                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 945                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 946                     !is_power_of_2(sbi->s_inode_size) ||
 947                     (sbi->s_inode_size > blocksize)) {
 948                         ext2_msg(sb, KERN_ERR,
 949                                 "error: unsupported inode size: %d",
 950                                 sbi->s_inode_size);
 951                         goto failed_mount;
 952                 }
 953         }
 954
 955         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 956                                    le32_to_cpu(es->s_log_frag_size);
 957         if (sbi->s_frag_size == 0)
 958                 goto cantfind_ext2;
 959         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 960
 961         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 962         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 963         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 964
 965         if (EXT2_INODE_SIZE(sb) == 0)
 966                 goto cantfind_ext2;
 967         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 968         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 969                 goto cantfind_ext2;
 970         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 971                                         sbi->s_inodes_per_block;
 972         sbi->s_desc_per_block = sb->s_blocksize /
 973                                         sizeof (struct ext2_group_desc);
 974         sbi->s_sbh = bh;
 975         sbi->s_mount_state = le16_to_cpu(es->s_state);
 976         sbi->s_addr_per_block_bits =
 977                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 978         sbi->s_desc_per_block_bits =
 979                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
 980
 981         if (sb->s_magic != EXT2_SUPER_MAGIC)
 982                 goto cantfind_ext2;
 983
 984         if (sb->s_blocksize != bh->b_size) {
 985                 if (!silent)
 986                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
 987                 goto failed_mount;
 988         }
 989
 990         if (sb->s_blocksize != sbi->s_frag_size) {
 991                 ext2_msg(sb, KERN_ERR,
 992                         "error: fragsize %lu != blocksize %lu"
 993                         "(not supported yet)",
 994                         sbi->s_frag_size, sb->s_blocksize);
 995                 goto failed_mount;
 996         }
 997
 998         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 999                 ext2_msg(sb, KERN_ERR,
1000                         "error: #blocks per group too big: %lu",
1001                         sbi->s_blocks_per_group);
1002                 goto failed_mount;
1003         }
1004         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1005                 ext2_msg(sb, KERN_ERR,
1006                         "error: #fragments per group too big: %lu",
1007                         sbi->s_frags_per_group);
1008                 goto failed_mount;
1009         }
1010         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1011                 ext2_msg(sb, KERN_ERR,
1012                         "error: #inodes per group too big: %lu",
1013                         sbi->s_inodes_per_group);
1014                 goto failed_mount;
1015         }
1016
1017         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1018                 goto cantfind_ext2;
1019         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1020                                 le32_to_cpu(es->s_first_data_block) - 1)
1021                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1022         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1023                    EXT2_DESC_PER_BLOCK(sb);
1024         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1025         if (sbi->s_group_desc == NULL) {
1026                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1027                 goto failed_mount;
1028         }
1029         bgl_lock_init(sbi->s_blockgroup_lock);
1030         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1031         if (!sbi->s_debts) {
1032                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1033                 goto failed_mount_group_desc;
1034         }
1035         for (i = 0; i < db_count; i++) {
1036                 block = descriptor_loc(sb, logic_sb_block, i);
1037                 sbi->s_group_desc[i] = sb_bread(sb, block);
1038                 if (!sbi->s_group_desc[i]) {
1039                         for (j = 0; j < i; j++)
1040                                 brelse (sbi->s_group_desc[j]);
1041                         ext2_msg(sb, KERN_ERR,
1042                                 "error: unable to read group descriptors");
1043                         goto failed_mount_group_desc;
1044                 }
1045         }
1046         if (!ext2_check_descriptors (sb)) {
1047                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1048                 goto failed_mount2;
1049         }
1050         sbi->s_gdb_count = db_count;
1051         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1052         spin_lock_init(&sbi->s_next_gen_lock);
1053
1054         /* per fileystem reservation list head & lock */
1055         spin_lock_init(&sbi->s_rsv_window_lock);
1056         sbi->s_rsv_window_root = RB_ROOT;
1057         /*
1058          * Add a single, static dummy reservation to the start of the
1059          * reservation window list --- it gives us a placeholder for
1060          * append-at-start-of-list which makes the allocation logic
1061          * _much_ simpler.
1062          */
1063         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1064         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1065         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1066         sbi->s_rsv_window_head.rsv_goal_size = 0;
1067         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1068
1069         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1070                                 ext2_count_free_blocks(sb));
1071         if (!err) {
1072                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1073                                 ext2_count_free_inodes(sb));
1074         }
1075         if (!err) {
1076                 err = percpu_counter_init(&sbi->s_dirs_counter,
1077                                 ext2_count_dirs(sb));
1078         }
1079         if (err) {
1080                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1081                 goto failed_mount3;
1082         }
1083         /*
1084          * set up enough so that it can read an inode
1085          */
1086         sb->s_op = &ext2_sops;
1087         sb->s_export_op = &ext2_export_ops;
1088         sb->s_xattr = ext2_xattr_handlers;
1089
1090 #ifdef CONFIG_QUOTA
1091         sb->dq_op = &dquot_operations;
1092         sb->s_qcop = &dquot_quotactl_ops;
1093 #endif
1094
1095         root = ext2_iget(sb, EXT2_ROOT_INO);
1096         if (IS_ERR(root)) {
1097                 ret = PTR_ERR(root);
1098                 goto failed_mount3;
1099         }
1100         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1101                 iput(root);
1102                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1103                 goto failed_mount3;
1104         }
1105
1106         sb->s_root = d_make_root(root);
1107         if (!sb->s_root) {
1108                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1109                 ret = -ENOMEM;
1110                 goto failed_mount3;
1111         }
1112         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1113                 ext2_msg(sb, KERN_WARNING,
1114                         "warning: mounting ext3 filesystem as ext2");
1115         if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1116                 sb->s_flags |= MS_RDONLY;
1117         ext2_write_super(sb);
1118         return 0;
1119
1120 cantfind_ext2:
1121         if (!silent)
1122                 ext2_msg(sb, KERN_ERR,
1123                         "error: can't find an ext2 filesystem on dev %s.",
1124                         sb->s_id);
1125         goto failed_mount;
1126 failed_mount3:
1127         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1128         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1129         percpu_counter_destroy(&sbi->s_dirs_counter);
1130 failed_mount2:
1131         for (i = 0; i < db_count; i++)
1132                 brelse(sbi->s_group_desc[i]);
1133 failed_mount_group_desc:
1134         kfree(sbi->s_group_desc);
1135         kfree(sbi->s_debts);
1136 failed_mount:
1137         brelse(bh);
1138 failed_sbi:
1139         sb->s_fs_info = NULL;
1140         kfree(sbi->s_blockgroup_lock);
1141         kfree(sbi);
1142 failed:
1143         return ret;
1144 }
1145
1146 static void ext2_clear_super_error(struct super_block *sb)
1147 {
1148         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1149
1150         if (buffer_write_io_error(sbh)) {
1151                 /*
1152                  * Oh, dear.  A previous attempt to write the
1153                  * superblock failed.  This could happen because the
1154                  * USB device was yanked out.  Or it could happen to
1155                  * be a transient write error and maybe the block will
1156                  * be remapped.  Nothing we can do but to retry the
1157                  * write and hope for the best.
1158                  */
1159                 ext2_msg(sb, KERN_ERR,
1160                        "previous I/O error to superblock detected\n");
1161                 clear_buffer_write_io_error(sbh);
1162                 set_buffer_uptodate(sbh);
1163         }
1164 }
1165
1166 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1167                             int wait)
1168 {
1169         ext2_clear_super_error(sb);
1170         spin_lock(&EXT2_SB(sb)->s_lock);
1171         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1172         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1173         es->s_wtime = cpu_to_le32(get_seconds());
1174         /* unlock before we do IO */
1175         spin_unlock(&EXT2_SB(sb)->s_lock);
1176         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1177         if (wait)
1178                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1179 }
1180
1181 /*
1182  * In the second extended file system, it is not necessary to
1183  * write the super block since we use a mapping of the
1184  * disk super block in a buffer.
1185  *
1186  * However, this function is still used to set the fs valid
1187  * flags to 0.  We need to set this flag to 0 since the fs
1188  * may have been checked while mounted and e2fsck may have
1189  * set s_state to EXT2_VALID_FS after some corrections.
1190  */
1191 static int ext2_sync_fs(struct super_block *sb, int wait)
1192 {
1193         struct ext2_sb_info *sbi = EXT2_SB(sb);
1194         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1195
1196         /*
1197          * Write quota structures to quota file, sync_blockdev() will write
1198          * them to disk later
1199          */
1200         dquot_writeback_dquots(sb, -1);
1201
1202         spin_lock(&sbi->s_lock);
1203         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1204                 ext2_debug("setting valid to 0\n");
1205                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1206         }
1207         spin_unlock(&sbi->s_lock);
1208         ext2_sync_super(sb, es, wait);
1209         return 0;
1210 }
1211
1212 static int ext2_freeze(struct super_block *sb)
1213 {
1214         struct ext2_sb_info *sbi = EXT2_SB(sb);
1215
1216         /*
1217          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1218          * because we have unattached inodes and thus filesystem is not fully
1219          * consistent.
1220          */
1221         if (atomic_long_read(&sb->s_remove_count)) {
1222                 ext2_sync_fs(sb, 1);
1223                 return 0;
1224         }
1225         /* Set EXT2_FS_VALID flag */
1226         spin_lock(&sbi->s_lock);
1227         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1228         spin_unlock(&sbi->s_lock);
1229         ext2_sync_super(sb, sbi->s_es, 1);
1230
1231         return 0;
1232 }
1233
1234 static int ext2_unfreeze(struct super_block *sb)
1235 {
1236         /* Just write sb to clear EXT2_VALID_FS flag */
1237         ext2_write_super(sb);
1238
1239         return 0;
1240 }
1241
1242 void ext2_write_super(struct super_block *sb)
1243 {
1244         if (!(sb->s_flags & MS_RDONLY))
1245                 ext2_sync_fs(sb, 1);
1246 }
1247
1248 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1249 {
1250         struct ext2_sb_info * sbi = EXT2_SB(sb);
1251         struct ext2_super_block * es;
1252         unsigned long old_mount_opt = sbi->s_mount_opt;
1253         struct ext2_mount_options old_opts;
1254         unsigned long old_sb_flags;
1255         int err;
1256
1257         sync_filesystem(sb);
1258         spin_lock(&sbi->s_lock);
1259
1260         /* Store the old options */
1261         old_sb_flags = sb->s_flags;
1262         old_opts.s_mount_opt = sbi->s_mount_opt;
1263         old_opts.s_resuid = sbi->s_resuid;
1264         old_opts.s_resgid = sbi->s_resgid;
1265
1266         /*
1267          * Allow the "check" option to be passed as a remount option.
1268          */
1269         if (!parse_options(data, sb)) {
1270                 err = -EINVAL;
1271                 goto restore_opts;
1272         }
1273
1274         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1275                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1276
1277         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1278                                     EXT2_MOUNT_XIP if not */
1279
1280         if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1281                 ext2_msg(sb, KERN_WARNING,
1282                         "warning: unsupported blocksize for xip");
1283                 err = -EINVAL;
1284                 goto restore_opts;
1285         }
1286
1287         es = sbi->s_es;
1288         if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
1289                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1290                          "xip flag with busy inodes while remounting");
1291                 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1292                 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1293         }
1294         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1295                 spin_unlock(&sbi->s_lock);
1296                 return 0;
1297         }
1298         if (*flags & MS_RDONLY) {
1299                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1300                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
1301                         spin_unlock(&sbi->s_lock);
1302                         return 0;
1303                 }
1304
1305                 /*
1306                  * OK, we are remounting a valid rw partition rdonly, so set
1307                  * the rdonly flag and then mark the partition as valid again.
1308                  */
1309                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1310                 es->s_mtime = cpu_to_le32(get_seconds());
1311                 spin_unlock(&sbi->s_lock);
1312
1313                 err = dquot_suspend(sb, -1);
1314                 if (err < 0) {
1315                         spin_lock(&sbi->s_lock);
1316                         goto restore_opts;
1317                 }
1318
1319                 ext2_sync_super(sb, es, 1);
1320         } else {
1321                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1322                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1323                 if (ret) {
1324                         ext2_msg(sb, KERN_WARNING,
1325                                 "warning: couldn't remount RDWR because of "
1326                                 "unsupported optional features (%x).",
1327                                 le32_to_cpu(ret));
1328                         err = -EROFS;
1329                         goto restore_opts;
1330                 }
1331                 /*
1332                  * Mounting a RDONLY partition read-write, so reread and
1333                  * store the current valid flag.  (It may have been changed
1334                  * by e2fsck since we originally mounted the partition.)
1335                  */
1336                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1337                 if (!ext2_setup_super (sb, es, 0))
1338                         sb->s_flags &= ~MS_RDONLY;
1339                 spin_unlock(&sbi->s_lock);
1340
1341                 ext2_write_super(sb);
1342
1343                 dquot_resume(sb, -1);
1344         }
1345
1346         return 0;
1347 restore_opts:
1348         sbi->s_mount_opt = old_opts.s_mount_opt;
1349         sbi->s_resuid = old_opts.s_resuid;
1350         sbi->s_resgid = old_opts.s_resgid;
1351         sb->s_flags = old_sb_flags;
1352         spin_unlock(&sbi->s_lock);
1353         return err;
1354 }
1355
1356 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1357 {
1358         struct super_block *sb = dentry->d_sb;
1359         struct ext2_sb_info *sbi = EXT2_SB(sb);
1360         struct ext2_super_block *es = sbi->s_es;
1361         u64 fsid;
1362
1363         spin_lock(&sbi->s_lock);
1364
1365         if (test_opt (sb, MINIX_DF))
1366                 sbi->s_overhead_last = 0;
1367         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1368                 unsigned long i, overhead = 0;
1369                 smp_rmb();
1370
1371                 /*
1372                  * Compute the overhead (FS structures). This is constant
1373                  * for a given filesystem unless the number of block groups
1374                  * changes so we cache the previous value until it does.
1375                  */
1376
1377                 /*
1378                  * All of the blocks before first_data_block are
1379                  * overhead
1380                  */
1381                 overhead = le32_to_cpu(es->s_first_data_block);
1382
1383                 /*
1384                  * Add the overhead attributed to the superblock and
1385                  * block group descriptors.  If the sparse superblocks
1386                  * feature is turned on, then not all groups have this.
1387                  */
1388                 for (i = 0; i < sbi->s_groups_count; i++)
1389                         overhead += ext2_bg_has_super(sb, i) +
1390                                 ext2_bg_num_gdb(sb, i);
1391
1392                 /*
1393                  * Every block group has an inode bitmap, a block
1394                  * bitmap, and an inode table.
1395                  */
1396                 overhead += (sbi->s_groups_count *
1397                              (2 + sbi->s_itb_per_group));
1398                 sbi->s_overhead_last = overhead;
1399                 smp_wmb();
1400                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1401         }
1402
1403         buf->f_type = EXT2_SUPER_MAGIC;
1404         buf->f_bsize = sb->s_blocksize;
1405         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1406         buf->f_bfree = ext2_count_free_blocks(sb);
1407         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1408         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1409         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1410                 buf->f_bavail = 0;
1411         buf->f_files = le32_to_cpu(es->s_inodes_count);
1412         buf->f_ffree = ext2_count_free_inodes(sb);
1413         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1414         buf->f_namelen = EXT2_NAME_LEN;
1415         fsid = le64_to_cpup((void *)es->s_uuid) ^
1416                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1417         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1418         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1419         spin_unlock(&sbi->s_lock);
1420         return 0;
1421 }
1422
1423 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1424         int flags, const char *dev_name, void *data)
1425 {
1426         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1427 }
1428
1429 #ifdef CONFIG_QUOTA
1430
1431 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1432  * acquiring the locks... As quota files are never truncated and quota code
1433  * itself serializes the operations (and no one else should touch the files)
1434  * we don't have to be afraid of races */
1435 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1436                                size_t len, loff_t off)
1437 {
1438         struct inode *inode = sb_dqopt(sb)->files[type];
1439         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1440         int err = 0;
1441         int offset = off & (sb->s_blocksize - 1);
1442         int tocopy;
1443         size_t toread;
1444         struct buffer_head tmp_bh;
1445         struct buffer_head *bh;
1446         loff_t i_size = i_size_read(inode);
1447
1448         if (off > i_size)
1449                 return 0;
1450         if (off+len > i_size)
1451                 len = i_size-off;
1452         toread = len;
1453         while (toread > 0) {
1454                 tocopy = sb->s_blocksize - offset < toread ?
1455                                 sb->s_blocksize - offset : toread;
1456
1457                 tmp_bh.b_state = 0;
1458                 tmp_bh.b_size = sb->s_blocksize;
1459                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1460                 if (err < 0)
1461                         return err;
1462                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1463                         memset(data, 0, tocopy);
1464                 else {
1465                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1466                         if (!bh)
1467                                 return -EIO;
1468                         memcpy(data, bh->b_data+offset, tocopy);
1469                         brelse(bh);
1470                 }
1471                 offset = 0;
1472                 toread -= tocopy;
1473                 data += tocopy;
1474                 blk++;
1475         }
1476         return len;
1477 }
1478
1479 /* Write to quotafile */
1480 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1481                                 const char *data, size_t len, loff_t off)
1482 {
1483         struct inode *inode = sb_dqopt(sb)->files[type];
1484         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1485         int err = 0;
1486         int offset = off & (sb->s_blocksize - 1);
1487         int tocopy;
1488         size_t towrite = len;
1489         struct buffer_head tmp_bh;
1490         struct buffer_head *bh;
1491
1492         while (towrite > 0) {
1493                 tocopy = sb->s_blocksize - offset < towrite ?
1494                                 sb->s_blocksize - offset : towrite;
1495
1496                 tmp_bh.b_state = 0;
1497                 tmp_bh.b_size = sb->s_blocksize;
1498                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1499                 if (err < 0)
1500                         goto out;
1501                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1502                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1503                 else
1504                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1505                 if (unlikely(!bh)) {
1506                         err = -EIO;
1507                         goto out;
1508                 }
1509                 lock_buffer(bh);
1510                 memcpy(bh->b_data+offset, data, tocopy);
1511                 flush_dcache_page(bh->b_page);
1512                 set_buffer_uptodate(bh);
1513                 mark_buffer_dirty(bh);
1514                 unlock_buffer(bh);
1515                 brelse(bh);
1516                 offset = 0;
1517                 towrite -= tocopy;
1518                 data += tocopy;
1519                 blk++;
1520         }
1521 out:
1522         if (len == towrite)
1523                 return err;
1524         if (inode->i_size < off+len-towrite)
1525                 i_size_write(inode, off+len-towrite);
1526         inode->i_version++;
1527         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1528         mark_inode_dirty(inode);
1529         return len - towrite;
1530 }
1531
1532 #endif
1533
1534 static struct file_system_type ext2_fs_type = {
1535         .owner          = THIS_MODULE,
1536         .name           = "ext2",
1537         .mount          = ext2_mount,
1538         .kill_sb        = kill_block_super,
1539         .fs_flags       = FS_REQUIRES_DEV,
1540 };
1541 MODULE_ALIAS_FS("ext2");
1542
1543 static int __init init_ext2_fs(void)
1544 {
1545         int err = init_ext2_xattr();
1546         if (err)
1547                 return err;
1548         err = init_inodecache();
1549         if (err)
1550                 goto out1;
1551         err = register_filesystem(&ext2_fs_type);
1552         if (err)
1553                 goto out;
1554         return 0;
1555 out:
1556         destroy_inodecache();
1557 out1:
1558         exit_ext2_xattr();
1559         return err;
1560 }
1561
1562 static void __exit exit_ext2_fs(void)
1563 {
1564         unregister_filesystem(&ext2_fs_type);
1565         destroy_inodecache();
1566         exit_ext2_xattr();
1567 }
1568
1569 MODULE_AUTHOR("Remy Card and others");
1570 MODULE_DESCRIPTION("Second Extended Filesystem");
1571 MODULE_LICENSE("GPL");
1572 module_init(init_ext2_fs)
1573 module_exit(exit_ext2_fs)