kernel/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
  39 static void ext2_sync_super(struct super_block *sb,
  40                             struct ext2_super_block *es, int wait);
  41 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  42 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  43 static int ext2_sync_fs(struct super_block *sb, int wait);
  44 static int ext2_freeze(struct super_block *sb);
  45 static int ext2_unfreeze(struct super_block *sb);
  46
  47 void ext2_error(struct super_block *sb, const char *function,
  48                 const char *fmt, ...)
  49 {
  50         struct va_format vaf;
  51         va_list args;
  52         struct ext2_sb_info *sbi = EXT2_SB(sb);
  53         struct ext2_super_block *es = sbi->s_es;
  54
  55         if (!(sb->s_flags & MS_RDONLY)) {
  56                 spin_lock(&sbi->s_lock);
  57                 sbi->s_mount_state |= EXT2_ERROR_FS;
  58                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  59                 spin_unlock(&sbi->s_lock);
  60                 ext2_sync_super(sb, es, 1);
  61         }
  62
  63         va_start(args, fmt);
  64
  65         vaf.fmt = fmt;
  66         vaf.va = &args;
  67
  68         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  69                sb->s_id, function, &vaf);
  70
  71         va_end(args);
  72
  73         if (test_opt(sb, ERRORS_PANIC))
  74                 panic("EXT2-fs: panic from previous error\n");
  75         if (test_opt(sb, ERRORS_RO)) {
  76                 ext2_msg(sb, KERN_CRIT,
  77                              "error: remounting filesystem read-only");
  78                 sb->s_flags |= MS_RDONLY;
  79         }
  80 }
  81
  82 void ext2_msg(struct super_block *sb, const char *prefix,
  83                 const char *fmt, ...)
  84 {
  85         struct va_format vaf;
  86         va_list args;
  87
  88         va_start(args, fmt);
  89
  90         vaf.fmt = fmt;
  91         vaf.va = &args;
  92
  93         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  94
  95         va_end(args);
  96 }
  97
  98 /*
  99  * This must be called with sbi->s_lock held.
 100  */
 101 void ext2_update_dynamic_rev(struct super_block *sb)
 102 {
 103         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 104
 105         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 106                 return;
 107
 108         ext2_msg(sb, KERN_WARNING,
 109                      "warning: updating to rev %d because of "
 110                      "new feature flag, running e2fsck is recommended",
 111                      EXT2_DYNAMIC_REV);
 112
 113         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 114         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 115         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 116         /* leave es->s_feature_*compat flags alone */
 117         /* es->s_uuid will be set by e2fsck if empty */
 118
 119         /*
 120          * The rest of the superblock fields should be zero, and if not it
 121          * means they are likely already in use, so leave them alone.  We
 122          * can leave it up to e2fsck to clean up any inconsistencies there.
 123          */
 124 }
 125
 126 static void ext2_put_super (struct super_block * sb)
 127 {
 128         int db_count;
 129         int i;
 130         struct ext2_sb_info *sbi = EXT2_SB(sb);
 131
 132         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 133
 134         ext2_xattr_put_super(sb);
 135         if (!(sb->s_flags & MS_RDONLY)) {
 136                 struct ext2_super_block *es = sbi->s_es;
 137
 138                 spin_lock(&sbi->s_lock);
 139                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 140                 spin_unlock(&sbi->s_lock);
 141                 ext2_sync_super(sb, es, 1);
 142         }
 143         db_count = sbi->s_gdb_count;
 144         for (i = 0; i < db_count; i++)
 145                 if (sbi->s_group_desc[i])
 146                         brelse (sbi->s_group_desc[i]);
 147         kfree(sbi->s_group_desc);
 148         kfree(sbi->s_debts);
 149         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 150         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 151         percpu_counter_destroy(&sbi->s_dirs_counter);
 152         brelse (sbi->s_sbh);
 153         sb->s_fs_info = NULL;
 154         kfree(sbi->s_blockgroup_lock);
 155         kfree(sbi);
 156 }
 157
 158 static struct kmem_cache * ext2_inode_cachep;
 159
 160 static struct inode *ext2_alloc_inode(struct super_block *sb)
 161 {
 162         struct ext2_inode_info *ei;
 163         ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 164         if (!ei)
 165                 return NULL;
 166         ei->i_block_alloc_info = NULL;
 167         ei->vfs_inode.i_version = 1;
 168 #ifdef CONFIG_QUOTA
 169         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 170 #endif
 171
 172         return &ei->vfs_inode;
 173 }
 174
 175 static void ext2_i_callback(struct rcu_head *head)
 176 {
 177         struct inode *inode = container_of(head, struct inode, i_rcu);
 178         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 179 }
 180
 181 static void ext2_destroy_inode(struct inode *inode)
 182 {
 183         call_rcu(&inode->i_rcu, ext2_i_callback);
 184 }
 185
 186 static void init_once(void *foo)
 187 {
 188         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 189
 190         rwlock_init(&ei->i_meta_lock);
 191 #ifdef CONFIG_EXT2_FS_XATTR
 192         init_rwsem(&ei->xattr_sem);
 193 #endif
 194         mutex_init(&ei->truncate_mutex);
 195 #ifdef CONFIG_FS_DAX
 196         init_rwsem(&ei->dax_sem);
 197 #endif
 198         inode_init_once(&ei->vfs_inode);
 199 }
 200
 201 static int __init init_inodecache(void)
 202 {
 203         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 204                                              sizeof(struct ext2_inode_info),
 205                                              0, (SLAB_RECLAIM_ACCOUNT|
 206                                                 SLAB_MEM_SPREAD),
 207                                              init_once);
 208         if (ext2_inode_cachep == NULL)
 209                 return -ENOMEM;
 210         return 0;
 211 }
 212
 213 static void destroy_inodecache(void)
 214 {
 215         /*
 216          * Make sure all delayed rcu free inodes are flushed before we
 217          * destroy cache.
 218          */
 219         rcu_barrier();
 220         kmem_cache_destroy(ext2_inode_cachep);
 221 }
 222
 223 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 224 {
 225         struct super_block *sb = root->d_sb;
 226         struct ext2_sb_info *sbi = EXT2_SB(sb);
 227         struct ext2_super_block *es = sbi->s_es;
 228         unsigned long def_mount_opts;
 229
 230         spin_lock(&sbi->s_lock);
 231         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 232
 233         if (sbi->s_sb_block != 1)
 234                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 235         if (test_opt(sb, MINIX_DF))
 236                 seq_puts(seq, ",minixdf");
 237         if (test_opt(sb, GRPID))
 238                 seq_puts(seq, ",grpid");
 239         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 240                 seq_puts(seq, ",nogrpid");
 241         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 242             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 243                 seq_printf(seq, ",resuid=%u",
 244                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 245         }
 246         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 247             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 248                 seq_printf(seq, ",resgid=%u",
 249                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 250         }
 251         if (test_opt(sb, ERRORS_RO)) {
 252                 int def_errors = le16_to_cpu(es->s_errors);
 253
 254                 if (def_errors == EXT2_ERRORS_PANIC ||
 255                     def_errors == EXT2_ERRORS_CONTINUE) {
 256                         seq_puts(seq, ",errors=remount-ro");
 257                 }
 258         }
 259         if (test_opt(sb, ERRORS_CONT))
 260                 seq_puts(seq, ",errors=continue");
 261         if (test_opt(sb, ERRORS_PANIC))
 262                 seq_puts(seq, ",errors=panic");
 263         if (test_opt(sb, NO_UID32))
 264                 seq_puts(seq, ",nouid32");
 265         if (test_opt(sb, DEBUG))
 266                 seq_puts(seq, ",debug");
 267         if (test_opt(sb, OLDALLOC))
 268                 seq_puts(seq, ",oldalloc");
 269
 270 #ifdef CONFIG_EXT2_FS_XATTR
 271         if (test_opt(sb, XATTR_USER))
 272                 seq_puts(seq, ",user_xattr");
 273         if (!test_opt(sb, XATTR_USER) &&
 274             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 275                 seq_puts(seq, ",nouser_xattr");
 276         }
 277 #endif
 278
 279 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 280         if (test_opt(sb, POSIX_ACL))
 281                 seq_puts(seq, ",acl");
 282         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 283                 seq_puts(seq, ",noacl");
 284 #endif
 285
 286         if (test_opt(sb, NOBH))
 287                 seq_puts(seq, ",nobh");
 288
 289 #if defined(CONFIG_QUOTA)
 290         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 291                 seq_puts(seq, ",usrquota");
 292
 293         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 294                 seq_puts(seq, ",grpquota");
 295 #endif
 296
 297 #ifdef CONFIG_FS_DAX
 298         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 299                 seq_puts(seq, ",xip");
 300         if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
 301                 seq_puts(seq, ",dax");
 302 #endif
 303
 304         if (!test_opt(sb, RESERVATION))
 305                 seq_puts(seq, ",noreservation");
 306
 307         spin_unlock(&sbi->s_lock);
 308         return 0;
 309 }
 310
 311 #ifdef CONFIG_QUOTA
 312 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 313 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 314 static struct dquot **ext2_get_dquots(struct inode *inode)
 315 {
 316         return EXT2_I(inode)->i_dquot;
 317 }
 318 #endif
 319
 320 static const struct super_operations ext2_sops = {
 321         .alloc_inode    = ext2_alloc_inode,
 322         .destroy_inode  = ext2_destroy_inode,
 323         .write_inode    = ext2_write_inode,
 324         .evict_inode    = ext2_evict_inode,
 325         .put_super      = ext2_put_super,
 326         .sync_fs        = ext2_sync_fs,
 327         .freeze_fs      = ext2_freeze,
 328         .unfreeze_fs    = ext2_unfreeze,
 329         .statfs         = ext2_statfs,
 330         .remount_fs     = ext2_remount,
 331         .show_options   = ext2_show_options,
 332 #ifdef CONFIG_QUOTA
 333         .quota_read     = ext2_quota_read,
 334         .quota_write    = ext2_quota_write,
 335         .get_dquots     = ext2_get_dquots,
 336 #endif
 337 };
 338
 339 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 340                 u64 ino, u32 generation)
 341 {
 342         struct inode *inode;
 343
 344         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 345                 return ERR_PTR(-ESTALE);
 346         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 347                 return ERR_PTR(-ESTALE);
 348
 349         /*
 350          * ext2_iget isn't quite right if the inode is currently unallocated!
 351          * However ext2_iget currently does appropriate checks to handle stale
 352          * inodes so everything is OK.
 353          */
 354         inode = ext2_iget(sb, ino);
 355         if (IS_ERR(inode))
 356                 return ERR_CAST(inode);
 357         if (generation && inode->i_generation != generation) {
 358                 /* we didn't find the right inode.. */
 359                 iput(inode);
 360                 return ERR_PTR(-ESTALE);
 361         }
 362         return inode;
 363 }
 364
 365 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 366                 int fh_len, int fh_type)
 367 {
 368         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 369                                     ext2_nfs_get_inode);
 370 }
 371
 372 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 373                 int fh_len, int fh_type)
 374 {
 375         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 376                                     ext2_nfs_get_inode);
 377 }
 378
 379 static const struct export_operations ext2_export_ops = {
 380         .fh_to_dentry = ext2_fh_to_dentry,
 381         .fh_to_parent = ext2_fh_to_parent,
 382         .get_parent = ext2_get_parent,
 383 };
 384
 385 static unsigned long get_sb_block(void **data)
 386 {
 387         unsigned long   sb_block;
 388         char            *options = (char *) *data;
 389
 390         if (!options || strncmp(options, "sb=", 3) != 0)
 391                 return 1;       /* Default location */
 392         options += 3;
 393         sb_block = simple_strtoul(options, &options, 0);
 394         if (*options && *options != ',') {
 395                 printk("EXT2-fs: Invalid sb specification: %s\n",
 396                        (char *) *data);
 397                 return 1;
 398         }
 399         if (*options == ',')
 400                 options++;
 401         *data = (void *) options;
 402         return sb_block;
 403 }
 404
 405 enum {
 406         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 407         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 408         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 409         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 410         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 411         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 412 };
 413
 414 static const match_table_t tokens = {
 415         {Opt_bsd_df, "bsddf"},
 416         {Opt_minix_df, "minixdf"},
 417         {Opt_grpid, "grpid"},
 418         {Opt_grpid, "bsdgroups"},
 419         {Opt_nogrpid, "nogrpid"},
 420         {Opt_nogrpid, "sysvgroups"},
 421         {Opt_resgid, "resgid=%u"},
 422         {Opt_resuid, "resuid=%u"},
 423         {Opt_sb, "sb=%u"},
 424         {Opt_err_cont, "errors=continue"},
 425         {Opt_err_panic, "errors=panic"},
 426         {Opt_err_ro, "errors=remount-ro"},
 427         {Opt_nouid32, "nouid32"},
 428         {Opt_nocheck, "check=none"},
 429         {Opt_nocheck, "nocheck"},
 430         {Opt_debug, "debug"},
 431         {Opt_oldalloc, "oldalloc"},
 432         {Opt_orlov, "orlov"},
 433         {Opt_nobh, "nobh"},
 434         {Opt_user_xattr, "user_xattr"},
 435         {Opt_nouser_xattr, "nouser_xattr"},
 436         {Opt_acl, "acl"},
 437         {Opt_noacl, "noacl"},
 438         {Opt_xip, "xip"},
 439         {Opt_dax, "dax"},
 440         {Opt_grpquota, "grpquota"},
 441         {Opt_ignore, "noquota"},
 442         {Opt_quota, "quota"},
 443         {Opt_usrquota, "usrquota"},
 444         {Opt_reservation, "reservation"},
 445         {Opt_noreservation, "noreservation"},
 446         {Opt_err, NULL}
 447 };
 448
 449 static int parse_options(char *options, struct super_block *sb)
 450 {
 451         char *p;
 452         struct ext2_sb_info *sbi = EXT2_SB(sb);
 453         substring_t args[MAX_OPT_ARGS];
 454         int option;
 455         kuid_t uid;
 456         kgid_t gid;
 457
 458         if (!options)
 459                 return 1;
 460
 461         while ((p = strsep (&options, ",")) != NULL) {
 462                 int token;
 463                 if (!*p)
 464                         continue;
 465
 466                 token = match_token(p, tokens, args);
 467                 switch (token) {
 468                 case Opt_bsd_df:
 469                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 470                         break;
 471                 case Opt_minix_df:
 472                         set_opt (sbi->s_mount_opt, MINIX_DF);
 473                         break;
 474                 case Opt_grpid:
 475                         set_opt (sbi->s_mount_opt, GRPID);
 476                         break;
 477                 case Opt_nogrpid:
 478                         clear_opt (sbi->s_mount_opt, GRPID);
 479                         break;
 480                 case Opt_resuid:
 481                         if (match_int(&args[0], &option))
 482                                 return 0;
 483                         uid = make_kuid(current_user_ns(), option);
 484                         if (!uid_valid(uid)) {
 485                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 486                                 return 0;
 487
 488                         }
 489                         sbi->s_resuid = uid;
 490                         break;
 491                 case Opt_resgid:
 492                         if (match_int(&args[0], &option))
 493                                 return 0;
 494                         gid = make_kgid(current_user_ns(), option);
 495                         if (!gid_valid(gid)) {
 496                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 497                                 return 0;
 498                         }
 499                         sbi->s_resgid = gid;
 500                         break;
 501                 case Opt_sb:
 502                         /* handled by get_sb_block() instead of here */
 503                         /* *sb_block = match_int(&args[0]); */
 504                         break;
 505                 case Opt_err_panic:
 506                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 507                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 508                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 509                         break;
 510                 case Opt_err_ro:
 511                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 512                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 513                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 514                         break;
 515                 case Opt_err_cont:
 516                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 517                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 518                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 519                         break;
 520                 case Opt_nouid32:
 521                         set_opt (sbi->s_mount_opt, NO_UID32);
 522                         break;
 523                 case Opt_nocheck:
 524                         clear_opt (sbi->s_mount_opt, CHECK);
 525                         break;
 526                 case Opt_debug:
 527                         set_opt (sbi->s_mount_opt, DEBUG);
 528                         break;
 529                 case Opt_oldalloc:
 530                         set_opt (sbi->s_mount_opt, OLDALLOC);
 531                         break;
 532                 case Opt_orlov:
 533                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 534                         break;
 535                 case Opt_nobh:
 536                         set_opt (sbi->s_mount_opt, NOBH);
 537                         break;
 538 #ifdef CONFIG_EXT2_FS_XATTR
 539                 case Opt_user_xattr:
 540                         set_opt (sbi->s_mount_opt, XATTR_USER);
 541                         break;
 542                 case Opt_nouser_xattr:
 543                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 544                         break;
 545 #else
 546                 case Opt_user_xattr:
 547                 case Opt_nouser_xattr:
 548                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 549                                 "not supported");
 550                         break;
 551 #endif
 552 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 553                 case Opt_acl:
 554                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 555                         break;
 556                 case Opt_noacl:
 557                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 558                         break;
 559 #else
 560                 case Opt_acl:
 561                 case Opt_noacl:
 562                         ext2_msg(sb, KERN_INFO,
 563                                 "(no)acl options not supported");
 564                         break;
 565 #endif
 566                 case Opt_xip:
 567                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 568                         set_opt(sbi->s_mount_opt, XIP);
 569                         /* Fall through */
 570                 case Opt_dax:
 571 #ifdef CONFIG_FS_DAX
 572                         ext2_msg(sb, KERN_WARNING,
 573                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 574                         set_opt(sbi->s_mount_opt, DAX);
 575 #else
 576                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 577 #endif
 578                         break;
 579
 580 #if defined(CONFIG_QUOTA)
 581                 case Opt_quota:
 582                 case Opt_usrquota:
 583                         set_opt(sbi->s_mount_opt, USRQUOTA);
 584                         break;
 585
 586                 case Opt_grpquota:
 587                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 588                         break;
 589 #else
 590                 case Opt_quota:
 591                 case Opt_usrquota:
 592                 case Opt_grpquota:
 593                         ext2_msg(sb, KERN_INFO,
 594                                 "quota operations not supported");
 595                         break;
 596 #endif
 597
 598                 case Opt_reservation:
 599                         set_opt(sbi->s_mount_opt, RESERVATION);
 600                         ext2_msg(sb, KERN_INFO, "reservations ON");
 601                         break;
 602                 case Opt_noreservation:
 603                         clear_opt(sbi->s_mount_opt, RESERVATION);
 604                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 605                         break;
 606                 case Opt_ignore:
 607                         break;
 608                 default:
 609                         return 0;
 610                 }
 611         }
 612         return 1;
 613 }
 614
 615 static int ext2_setup_super (struct super_block * sb,
 616                               struct ext2_super_block * es,
 617                               int read_only)
 618 {
 619         int res = 0;
 620         struct ext2_sb_info *sbi = EXT2_SB(sb);
 621
 622         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 623                 ext2_msg(sb, KERN_ERR,
 624                         "error: revision level too high, "
 625                         "forcing read-only mode");
 626                 res = MS_RDONLY;
 627         }
 628         if (read_only)
 629                 return res;
 630         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 631                 ext2_msg(sb, KERN_WARNING,
 632                         "warning: mounting unchecked fs, "
 633                         "running e2fsck is recommended");
 634         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 635                 ext2_msg(sb, KERN_WARNING,
 636                         "warning: mounting fs with errors, "
 637                         "running e2fsck is recommended");
 638         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 639                  le16_to_cpu(es->s_mnt_count) >=
 640                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 641                 ext2_msg(sb, KERN_WARNING,
 642                         "warning: maximal mount count reached, "
 643                         "running e2fsck is recommended");
 644         else if (le32_to_cpu(es->s_checkinterval) &&
 645                 (le32_to_cpu(es->s_lastcheck) +
 646                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 647                 ext2_msg(sb, KERN_WARNING,
 648                         "warning: checktime reached, "
 649                         "running e2fsck is recommended");
 650         if (!le16_to_cpu(es->s_max_mnt_count))
 651                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 652         le16_add_cpu(&es->s_mnt_count, 1);
 653         if (test_opt (sb, DEBUG))
 654                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 655                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 656                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 657                         sbi->s_frag_size,
 658                         sbi->s_groups_count,
 659                         EXT2_BLOCKS_PER_GROUP(sb),
 660                         EXT2_INODES_PER_GROUP(sb),
 661                         sbi->s_mount_opt);
 662         return res;
 663 }
 664
 665 static int ext2_check_descriptors(struct super_block *sb)
 666 {
 667         int i;
 668         struct ext2_sb_info *sbi = EXT2_SB(sb);
 669
 670         ext2_debug ("Checking group descriptors");
 671
 672         for (i = 0; i < sbi->s_groups_count; i++) {
 673                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 674                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 675                 ext2_fsblk_t last_block;
 676
 677                 if (i == sbi->s_groups_count - 1)
 678                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 679                 else
 680                         last_block = first_block +
 681                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 682
 683                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 684                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 685                 {
 686                         ext2_error (sb, "ext2_check_descriptors",
 687                                     "Block bitmap for group %d"
 688                                     " not in group (block %lu)!",
 689                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 690                         return 0;
 691                 }
 692                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 693                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 694                 {
 695                         ext2_error (sb, "ext2_check_descriptors",
 696                                     "Inode bitmap for group %d"
 697                                     " not in group (block %lu)!",
 698                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 699                         return 0;
 700                 }
 701                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 702                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 703                     last_block)
 704                 {
 705                         ext2_error (sb, "ext2_check_descriptors",
 706                                     "Inode table for group %d"
 707                                     " not in group (block %lu)!",
 708                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 709                         return 0;
 710                 }
 711         }
 712         return 1;
 713 }
 714
 715 /*
 716  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 717  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 718  * We need to be 1 filesystem block less than the 2^32 sector limit.
 719  */
 720 static loff_t ext2_max_size(int bits)
 721 {
 722         loff_t res = EXT2_NDIR_BLOCKS;
 723         int meta_blocks;
 724         loff_t upper_limit;
 725
 726         /* This is calculated to be the largest file size for a
 727          * dense, file such that the total number of
 728          * sectors in the file, including data and all indirect blocks,
 729          * does not exceed 2^32 -1
 730          * __u32 i_blocks representing the total number of
 731          * 512 bytes blocks of the file
 732          */
 733         upper_limit = (1LL << 32) - 1;
 734
 735         /* total blocks in file system block size */
 736         upper_limit >>= (bits - 9);
 737
 738
 739         /* indirect blocks */
 740         meta_blocks = 1;
 741         /* double indirect blocks */
 742         meta_blocks += 1 + (1LL << (bits-2));
 743         /* tripple indirect blocks */
 744         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 745
 746         upper_limit -= meta_blocks;
 747         upper_limit <<= bits;
 748
 749         res += 1LL << (bits-2);
 750         res += 1LL << (2*(bits-2));
 751         res += 1LL << (3*(bits-2));
 752         res <<= bits;
 753         if (res > upper_limit)
 754                 res = upper_limit;
 755
 756         if (res > MAX_LFS_FILESIZE)
 757                 res = MAX_LFS_FILESIZE;
 758
 759         return res;
 760 }
 761
 762 static unsigned long descriptor_loc(struct super_block *sb,
 763                                     unsigned long logic_sb_block,
 764                                     int nr)
 765 {
 766         struct ext2_sb_info *sbi = EXT2_SB(sb);
 767         unsigned long bg, first_meta_bg;
 768         int has_super = 0;
 769
 770         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 771
 772         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 773             nr < first_meta_bg)
 774                 return (logic_sb_block + nr + 1);
 775         bg = sbi->s_desc_per_block * nr;
 776         if (ext2_bg_has_super(sb, bg))
 777                 has_super = 1;
 778
 779         return ext2_group_first_block_no(sb, bg) + has_super;
 780 }
 781
 782 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 783 {
 784         struct buffer_head * bh;
 785         struct ext2_sb_info * sbi;
 786         struct ext2_super_block * es;
 787         struct inode *root;
 788         unsigned long block;
 789         unsigned long sb_block = get_sb_block(&data);
 790         unsigned long logic_sb_block;
 791         unsigned long offset = 0;
 792         unsigned long def_mount_opts;
 793         long ret = -EINVAL;
 794         int blocksize = BLOCK_SIZE;
 795         int db_count;
 796         int i, j;
 797         __le32 features;
 798         int err;
 799
 800         err = -ENOMEM;
 801         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 802         if (!sbi)
 803                 goto failed;
 804
 805         sbi->s_blockgroup_lock =
 806                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 807         if (!sbi->s_blockgroup_lock) {
 808                 kfree(sbi);
 809                 goto failed;
 810         }
 811         sb->s_fs_info = sbi;
 812         sbi->s_sb_block = sb_block;
 813
 814         spin_lock_init(&sbi->s_lock);
 815
 816         /*
 817          * See what the current blocksize for the device is, and
 818          * use that as the blocksize.  Otherwise (or if the blocksize
 819          * is smaller than the default) use the default.
 820          * This is important for devices that have a hardware
 821          * sectorsize that is larger than the default.
 822          */
 823         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 824         if (!blocksize) {
 825                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 826                 goto failed_sbi;
 827         }
 828
 829         /*
 830          * If the superblock doesn't start on a hardware sector boundary,
 831          * calculate the offset.
 832          */
 833         if (blocksize != BLOCK_SIZE) {
 834                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 835                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 836         } else {
 837                 logic_sb_block = sb_block;
 838         }
 839
 840         if (!(bh = sb_bread(sb, logic_sb_block))) {
 841                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 842                 goto failed_sbi;
 843         }
 844         /*
 845          * Note: s_es must be initialized as soon as possible because
 846          *       some ext2 macro-instructions depend on its value
 847          */
 848         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 849         sbi->s_es = es;
 850         sb->s_magic = le16_to_cpu(es->s_magic);
 851
 852         if (sb->s_magic != EXT2_SUPER_MAGIC)
 853                 goto cantfind_ext2;
 854
 855         /* Set defaults before we parse the mount options */
 856         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 857         if (def_mount_opts & EXT2_DEFM_DEBUG)
 858                 set_opt(sbi->s_mount_opt, DEBUG);
 859         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 860                 set_opt(sbi->s_mount_opt, GRPID);
 861         if (def_mount_opts & EXT2_DEFM_UID16)
 862                 set_opt(sbi->s_mount_opt, NO_UID32);
 863 #ifdef CONFIG_EXT2_FS_XATTR
 864         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 865                 set_opt(sbi->s_mount_opt, XATTR_USER);
 866 #endif
 867 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 868         if (def_mount_opts & EXT2_DEFM_ACL)
 869                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 870 #endif
 871
 872         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 873                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 874         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 875                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 876         else
 877                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 878
 879         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 880         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 881
 882         set_opt(sbi->s_mount_opt, RESERVATION);
 883
 884         if (!parse_options((char *) data, sb))
 885                 goto failed_mount;
 886
 887         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 888                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 889                  MS_POSIXACL : 0);
 890         sb->s_iflags |= SB_I_CGROUPWB;
 891
 892         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 893             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 894              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 895              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 896                 ext2_msg(sb, KERN_WARNING,
 897                         "warning: feature flags set on rev 0 fs, "
 898                         "running e2fsck is recommended");
 899         /*
 900          * Check feature flags regardless of the revision level, since we
 901          * previously didn't change the revision level when setting the flags,
 902          * so there is a chance incompat flags are set on a rev 0 filesystem.
 903          */
 904         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 905         if (features) {
 906                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 907                        "unsupported optional features (%x)",
 908                         le32_to_cpu(features));
 909                 goto failed_mount;
 910         }
 911         if (!(sb->s_flags & MS_RDONLY) &&
 912             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 913                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 914                        "unsupported optional features (%x)",
 915                        le32_to_cpu(features));
 916                 goto failed_mount;
 917         }
 918
 919         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 920
 921         if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
 922                 if (blocksize != PAGE_SIZE) {
 923                         ext2_msg(sb, KERN_ERR,
 924                                         "error: unsupported blocksize for dax");
 925                         goto failed_mount;
 926                 }
 927                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
 928                         ext2_msg(sb, KERN_ERR,
 929                                         "error: device does not support dax");
 930                         goto failed_mount;
 931                 }
 932         }
 933
 934         /* If the blocksize doesn't match, re-read the thing.. */
 935         if (sb->s_blocksize != blocksize) {
 936                 brelse(bh);
 937
 938                 if (!sb_set_blocksize(sb, blocksize)) {
 939                         ext2_msg(sb, KERN_ERR,
 940                                 "error: bad blocksize %d", blocksize);
 941                         goto failed_sbi;
 942                 }
 943
 944                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 945                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 946                 bh = sb_bread(sb, logic_sb_block);
 947                 if(!bh) {
 948                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 949                                 "superblock on 2nd try");
 950                         goto failed_sbi;
 951                 }
 952                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 953                 sbi->s_es = es;
 954                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 955                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 956                         goto failed_mount;
 957                 }
 958         }
 959
 960         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 961         sb->s_max_links = EXT2_LINK_MAX;
 962
 963         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 964                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 965                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 966         } else {
 967                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 968                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 969                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 970                     !is_power_of_2(sbi->s_inode_size) ||
 971                     (sbi->s_inode_size > blocksize)) {
 972                         ext2_msg(sb, KERN_ERR,
 973                                 "error: unsupported inode size: %d",
 974                                 sbi->s_inode_size);
 975                         goto failed_mount;
 976                 }
 977         }
 978
 979         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 980                                    le32_to_cpu(es->s_log_frag_size);
 981         if (sbi->s_frag_size == 0)
 982                 goto cantfind_ext2;
 983         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 984
 985         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 986         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 987         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 988
 989         if (EXT2_INODE_SIZE(sb) == 0)
 990                 goto cantfind_ext2;
 991         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 992         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 993                 goto cantfind_ext2;
 994         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 995                                         sbi->s_inodes_per_block;
 996         sbi->s_desc_per_block = sb->s_blocksize /
 997                                         sizeof (struct ext2_group_desc);
 998         sbi->s_sbh = bh;
 999         sbi->s_mount_state = le16_to_cpu(es->s_state);
1000         sbi->s_addr_per_block_bits =
1001                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1002         sbi->s_desc_per_block_bits =
1003                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1004
1005         if (sb->s_magic != EXT2_SUPER_MAGIC)
1006                 goto cantfind_ext2;
1007
1008         if (sb->s_blocksize != bh->b_size) {
1009                 if (!silent)
1010                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1011                 goto failed_mount;
1012         }
1013
1014         if (sb->s_blocksize != sbi->s_frag_size) {
1015                 ext2_msg(sb, KERN_ERR,
1016                         "error: fragsize %lu != blocksize %lu"
1017                         "(not supported yet)",
1018                         sbi->s_frag_size, sb->s_blocksize);
1019                 goto failed_mount;
1020         }
1021
1022         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1023                 ext2_msg(sb, KERN_ERR,
1024                         "error: #blocks per group too big: %lu",
1025                         sbi->s_blocks_per_group);
1026                 goto failed_mount;
1027         }
1028         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1029                 ext2_msg(sb, KERN_ERR,
1030                         "error: #fragments per group too big: %lu",
1031                         sbi->s_frags_per_group);
1032                 goto failed_mount;
1033         }
1034         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1035                 ext2_msg(sb, KERN_ERR,
1036                         "error: #inodes per group too big: %lu",
1037                         sbi->s_inodes_per_group);
1038                 goto failed_mount;
1039         }
1040
1041         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1042                 goto cantfind_ext2;
1043         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1044                                 le32_to_cpu(es->s_first_data_block) - 1)
1045                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1046         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1047                    EXT2_DESC_PER_BLOCK(sb);
1048         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1049         if (sbi->s_group_desc == NULL) {
1050                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1051                 goto failed_mount;
1052         }
1053         bgl_lock_init(sbi->s_blockgroup_lock);
1054         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1055         if (!sbi->s_debts) {
1056                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1057                 goto failed_mount_group_desc;
1058         }
1059         for (i = 0; i < db_count; i++) {
1060                 block = descriptor_loc(sb, logic_sb_block, i);
1061                 sbi->s_group_desc[i] = sb_bread(sb, block);
1062                 if (!sbi->s_group_desc[i]) {
1063                         for (j = 0; j < i; j++)
1064                                 brelse (sbi->s_group_desc[j]);
1065                         ext2_msg(sb, KERN_ERR,
1066                                 "error: unable to read group descriptors");
1067                         goto failed_mount_group_desc;
1068                 }
1069         }
1070         if (!ext2_check_descriptors (sb)) {
1071                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1072                 goto failed_mount2;
1073         }
1074         sbi->s_gdb_count = db_count;
1075         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1076         spin_lock_init(&sbi->s_next_gen_lock);
1077
1078         /* per fileystem reservation list head & lock */
1079         spin_lock_init(&sbi->s_rsv_window_lock);
1080         sbi->s_rsv_window_root = RB_ROOT;
1081         /*
1082          * Add a single, static dummy reservation to the start of the
1083          * reservation window list --- it gives us a placeholder for
1084          * append-at-start-of-list which makes the allocation logic
1085          * _much_ simpler.
1086          */
1087         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1088         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1089         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1090         sbi->s_rsv_window_head.rsv_goal_size = 0;
1091         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1092
1093         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1094                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1095         if (!err) {
1096                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1097                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1098         }
1099         if (!err) {
1100                 err = percpu_counter_init(&sbi->s_dirs_counter,
1101                                 ext2_count_dirs(sb), GFP_KERNEL);
1102         }
1103         if (err) {
1104                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1105                 goto failed_mount3;
1106         }
1107         /*
1108          * set up enough so that it can read an inode
1109          */
1110         sb->s_op = &ext2_sops;
1111         sb->s_export_op = &ext2_export_ops;
1112         sb->s_xattr = ext2_xattr_handlers;
1113
1114 #ifdef CONFIG_QUOTA
1115         sb->dq_op = &dquot_operations;
1116         sb->s_qcop = &dquot_quotactl_ops;
1117         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1118 #endif
1119
1120         root = ext2_iget(sb, EXT2_ROOT_INO);
1121         if (IS_ERR(root)) {
1122                 ret = PTR_ERR(root);
1123                 goto failed_mount3;
1124         }
1125         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1126                 iput(root);
1127                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1128                 goto failed_mount3;
1129         }
1130
1131         sb->s_root = d_make_root(root);
1132         if (!sb->s_root) {
1133                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1134                 ret = -ENOMEM;
1135                 goto failed_mount3;
1136         }
1137         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1138                 ext2_msg(sb, KERN_WARNING,
1139                         "warning: mounting ext3 filesystem as ext2");
1140         if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1141                 sb->s_flags |= MS_RDONLY;
1142         ext2_write_super(sb);
1143         return 0;
1144
1145 cantfind_ext2:
1146         if (!silent)
1147                 ext2_msg(sb, KERN_ERR,
1148                         "error: can't find an ext2 filesystem on dev %s.",
1149                         sb->s_id);
1150         goto failed_mount;
1151 failed_mount3:
1152         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1153         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1154         percpu_counter_destroy(&sbi->s_dirs_counter);
1155 failed_mount2:
1156         for (i = 0; i < db_count; i++)
1157                 brelse(sbi->s_group_desc[i]);
1158 failed_mount_group_desc:
1159         kfree(sbi->s_group_desc);
1160         kfree(sbi->s_debts);
1161 failed_mount:
1162         brelse(bh);
1163 failed_sbi:
1164         sb->s_fs_info = NULL;
1165         kfree(sbi->s_blockgroup_lock);
1166         kfree(sbi);
1167 failed:
1168         return ret;
1169 }
1170
1171 static void ext2_clear_super_error(struct super_block *sb)
1172 {
1173         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1174
1175         if (buffer_write_io_error(sbh)) {
1176                 /*
1177                  * Oh, dear.  A previous attempt to write the
1178                  * superblock failed.  This could happen because the
1179                  * USB device was yanked out.  Or it could happen to
1180                  * be a transient write error and maybe the block will
1181                  * be remapped.  Nothing we can do but to retry the
1182                  * write and hope for the best.
1183                  */
1184                 ext2_msg(sb, KERN_ERR,
1185                        "previous I/O error to superblock detected\n");
1186                 clear_buffer_write_io_error(sbh);
1187                 set_buffer_uptodate(sbh);
1188         }
1189 }
1190
1191 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1192                             int wait)
1193 {
1194         ext2_clear_super_error(sb);
1195         spin_lock(&EXT2_SB(sb)->s_lock);
1196         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1197         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1198         es->s_wtime = cpu_to_le32(get_seconds());
1199         /* unlock before we do IO */
1200         spin_unlock(&EXT2_SB(sb)->s_lock);
1201         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1202         if (wait)
1203                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1204 }
1205
1206 /*
1207  * In the second extended file system, it is not necessary to
1208  * write the super block since we use a mapping of the
1209  * disk super block in a buffer.
1210  *
1211  * However, this function is still used to set the fs valid
1212  * flags to 0.  We need to set this flag to 0 since the fs
1213  * may have been checked while mounted and e2fsck may have
1214  * set s_state to EXT2_VALID_FS after some corrections.
1215  */
1216 static int ext2_sync_fs(struct super_block *sb, int wait)
1217 {
1218         struct ext2_sb_info *sbi = EXT2_SB(sb);
1219         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1220
1221         /*
1222          * Write quota structures to quota file, sync_blockdev() will write
1223          * them to disk later
1224          */
1225         dquot_writeback_dquots(sb, -1);
1226
1227         spin_lock(&sbi->s_lock);
1228         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1229                 ext2_debug("setting valid to 0\n");
1230                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1231         }
1232         spin_unlock(&sbi->s_lock);
1233         ext2_sync_super(sb, es, wait);
1234         return 0;
1235 }
1236
1237 static int ext2_freeze(struct super_block *sb)
1238 {
1239         struct ext2_sb_info *sbi = EXT2_SB(sb);
1240
1241         /*
1242          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1243          * because we have unattached inodes and thus filesystem is not fully
1244          * consistent.
1245          */
1246         if (atomic_long_read(&sb->s_remove_count)) {
1247                 ext2_sync_fs(sb, 1);
1248                 return 0;
1249         }
1250         /* Set EXT2_FS_VALID flag */
1251         spin_lock(&sbi->s_lock);
1252         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1253         spin_unlock(&sbi->s_lock);
1254         ext2_sync_super(sb, sbi->s_es, 1);
1255
1256         return 0;
1257 }
1258
1259 static int ext2_unfreeze(struct super_block *sb)
1260 {
1261         /* Just write sb to clear EXT2_VALID_FS flag */
1262         ext2_write_super(sb);
1263
1264         return 0;
1265 }
1266
1267 void ext2_write_super(struct super_block *sb)
1268 {
1269         if (!(sb->s_flags & MS_RDONLY))
1270                 ext2_sync_fs(sb, 1);
1271 }
1272
1273 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1274 {
1275         struct ext2_sb_info * sbi = EXT2_SB(sb);
1276         struct ext2_super_block * es;
1277         struct ext2_mount_options old_opts;
1278         unsigned long old_sb_flags;
1279         int err;
1280
1281         sync_filesystem(sb);
1282         spin_lock(&sbi->s_lock);
1283
1284         /* Store the old options */
1285         old_sb_flags = sb->s_flags;
1286         old_opts.s_mount_opt = sbi->s_mount_opt;
1287         old_opts.s_resuid = sbi->s_resuid;
1288         old_opts.s_resgid = sbi->s_resgid;
1289
1290         /*
1291          * Allow the "check" option to be passed as a remount option.
1292          */
1293         if (!parse_options(data, sb)) {
1294                 err = -EINVAL;
1295                 goto restore_opts;
1296         }
1297
1298         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1299                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1300
1301         es = sbi->s_es;
1302         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1303                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1304                          "dax flag with busy inodes while remounting");
1305                 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1306         }
1307         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1308                 spin_unlock(&sbi->s_lock);
1309                 return 0;
1310         }
1311         if (*flags & MS_RDONLY) {
1312                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1313                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
1314                         spin_unlock(&sbi->s_lock);
1315                         return 0;
1316                 }
1317
1318                 /*
1319                  * OK, we are remounting a valid rw partition rdonly, so set
1320                  * the rdonly flag and then mark the partition as valid again.
1321                  */
1322                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1323                 es->s_mtime = cpu_to_le32(get_seconds());
1324                 spin_unlock(&sbi->s_lock);
1325
1326                 err = dquot_suspend(sb, -1);
1327                 if (err < 0) {
1328                         spin_lock(&sbi->s_lock);
1329                         goto restore_opts;
1330                 }
1331
1332                 ext2_sync_super(sb, es, 1);
1333         } else {
1334                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1335                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1336                 if (ret) {
1337                         ext2_msg(sb, KERN_WARNING,
1338                                 "warning: couldn't remount RDWR because of "
1339                                 "unsupported optional features (%x).",
1340                                 le32_to_cpu(ret));
1341                         err = -EROFS;
1342                         goto restore_opts;
1343                 }
1344                 /*
1345                  * Mounting a RDONLY partition read-write, so reread and
1346                  * store the current valid flag.  (It may have been changed
1347                  * by e2fsck since we originally mounted the partition.)
1348                  */
1349                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1350                 if (!ext2_setup_super (sb, es, 0))
1351                         sb->s_flags &= ~MS_RDONLY;
1352                 spin_unlock(&sbi->s_lock);
1353
1354                 ext2_write_super(sb);
1355
1356                 dquot_resume(sb, -1);
1357         }
1358
1359         return 0;
1360 restore_opts:
1361         sbi->s_mount_opt = old_opts.s_mount_opt;
1362         sbi->s_resuid = old_opts.s_resuid;
1363         sbi->s_resgid = old_opts.s_resgid;
1364         sb->s_flags = old_sb_flags;
1365         spin_unlock(&sbi->s_lock);
1366         return err;
1367 }
1368
1369 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1370 {
1371         struct super_block *sb = dentry->d_sb;
1372         struct ext2_sb_info *sbi = EXT2_SB(sb);
1373         struct ext2_super_block *es = sbi->s_es;
1374         u64 fsid;
1375
1376         spin_lock(&sbi->s_lock);
1377
1378         if (test_opt (sb, MINIX_DF))
1379                 sbi->s_overhead_last = 0;
1380         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1381                 unsigned long i, overhead = 0;
1382                 smp_rmb();
1383
1384                 /*
1385                  * Compute the overhead (FS structures). This is constant
1386                  * for a given filesystem unless the number of block groups
1387                  * changes so we cache the previous value until it does.
1388                  */
1389
1390                 /*
1391                  * All of the blocks before first_data_block are
1392                  * overhead
1393                  */
1394                 overhead = le32_to_cpu(es->s_first_data_block);
1395
1396                 /*
1397                  * Add the overhead attributed to the superblock and
1398                  * block group descriptors.  If the sparse superblocks
1399                  * feature is turned on, then not all groups have this.
1400                  */
1401                 for (i = 0; i < sbi->s_groups_count; i++)
1402                         overhead += ext2_bg_has_super(sb, i) +
1403                                 ext2_bg_num_gdb(sb, i);
1404
1405                 /*
1406                  * Every block group has an inode bitmap, a block
1407                  * bitmap, and an inode table.
1408                  */
1409                 overhead += (sbi->s_groups_count *
1410                              (2 + sbi->s_itb_per_group));
1411                 sbi->s_overhead_last = overhead;
1412                 smp_wmb();
1413                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1414         }
1415
1416         buf->f_type = EXT2_SUPER_MAGIC;
1417         buf->f_bsize = sb->s_blocksize;
1418         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1419         buf->f_bfree = ext2_count_free_blocks(sb);
1420         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1421         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1422         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1423                 buf->f_bavail = 0;
1424         buf->f_files = le32_to_cpu(es->s_inodes_count);
1425         buf->f_ffree = ext2_count_free_inodes(sb);
1426         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1427         buf->f_namelen = EXT2_NAME_LEN;
1428         fsid = le64_to_cpup((void *)es->s_uuid) ^
1429                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1430         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1431         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1432         spin_unlock(&sbi->s_lock);
1433         return 0;
1434 }
1435
1436 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1437         int flags, const char *dev_name, void *data)
1438 {
1439         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1440 }
1441
1442 #ifdef CONFIG_QUOTA
1443
1444 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1445  * acquiring the locks... As quota files are never truncated and quota code
1446  * itself serializes the operations (and no one else should touch the files)
1447  * we don't have to be afraid of races */
1448 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1449                                size_t len, loff_t off)
1450 {
1451         struct inode *inode = sb_dqopt(sb)->files[type];
1452         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1453         int err = 0;
1454         int offset = off & (sb->s_blocksize - 1);
1455         int tocopy;
1456         size_t toread;
1457         struct buffer_head tmp_bh;
1458         struct buffer_head *bh;
1459         loff_t i_size = i_size_read(inode);
1460
1461         if (off > i_size)
1462                 return 0;
1463         if (off+len > i_size)
1464                 len = i_size-off;
1465         toread = len;
1466         while (toread > 0) {
1467                 tocopy = sb->s_blocksize - offset < toread ?
1468                                 sb->s_blocksize - offset : toread;
1469
1470                 tmp_bh.b_state = 0;
1471                 tmp_bh.b_size = sb->s_blocksize;
1472                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1473                 if (err < 0)
1474                         return err;
1475                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1476                         memset(data, 0, tocopy);
1477                 else {
1478                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1479                         if (!bh)
1480                                 return -EIO;
1481                         memcpy(data, bh->b_data+offset, tocopy);
1482                         brelse(bh);
1483                 }
1484                 offset = 0;
1485                 toread -= tocopy;
1486                 data += tocopy;
1487                 blk++;
1488         }
1489         return len;
1490 }
1491
1492 /* Write to quotafile */
1493 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1494                                 const char *data, size_t len, loff_t off)
1495 {
1496         struct inode *inode = sb_dqopt(sb)->files[type];
1497         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1498         int err = 0;
1499         int offset = off & (sb->s_blocksize - 1);
1500         int tocopy;
1501         size_t towrite = len;
1502         struct buffer_head tmp_bh;
1503         struct buffer_head *bh;
1504
1505         while (towrite > 0) {
1506                 tocopy = sb->s_blocksize - offset < towrite ?
1507                                 sb->s_blocksize - offset : towrite;
1508
1509                 tmp_bh.b_state = 0;
1510                 tmp_bh.b_size = sb->s_blocksize;
1511                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1512                 if (err < 0)
1513                         goto out;
1514                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1515                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1516                 else
1517                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1518                 if (unlikely(!bh)) {
1519                         err = -EIO;
1520                         goto out;
1521                 }
1522                 lock_buffer(bh);
1523                 memcpy(bh->b_data+offset, data, tocopy);
1524                 flush_dcache_page(bh->b_page);
1525                 set_buffer_uptodate(bh);
1526                 mark_buffer_dirty(bh);
1527                 unlock_buffer(bh);
1528                 brelse(bh);
1529                 offset = 0;
1530                 towrite -= tocopy;
1531                 data += tocopy;
1532                 blk++;
1533         }
1534 out:
1535         if (len == towrite)
1536                 return err;
1537         if (inode->i_size < off+len-towrite)
1538                 i_size_write(inode, off+len-towrite);
1539         inode->i_version++;
1540         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1541         mark_inode_dirty(inode);
1542         return len - towrite;
1543 }
1544
1545 #endif
1546
1547 static struct file_system_type ext2_fs_type = {
1548         .owner          = THIS_MODULE,
1549         .name           = "ext2",
1550         .mount          = ext2_mount,
1551         .kill_sb        = kill_block_super,
1552         .fs_flags       = FS_REQUIRES_DEV,
1553 };
1554 MODULE_ALIAS_FS("ext2");
1555
1556 static int __init init_ext2_fs(void)
1557 {
1558         int err = init_ext2_xattr();
1559         if (err)
1560                 return err;
1561         err = init_inodecache();
1562         if (err)
1563                 goto out1;
1564         err = register_filesystem(&ext2_fs_type);
1565         if (err)
1566                 goto out;
1567         return 0;
1568 out:
1569         destroy_inodecache();
1570 out1:
1571         exit_ext2_xattr();
1572         return err;
1573 }
1574
1575 static void __exit exit_ext2_fs(void)
1576 {
1577         unregister_filesystem(&ext2_fs_type);
1578         destroy_inodecache();
1579         exit_ext2_xattr();
1580 }
1581
1582 MODULE_AUTHOR("Remy Card and others");
1583 MODULE_DESCRIPTION("Second Extended Filesystem");
1584 MODULE_LICENSE("GPL");
1585 module_init(init_ext2_fs)
1586 module_exit(exit_ext2_fs)