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                         set_opt(sbi->s_mount_opt, DAX);
 573 #else
 574                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 575 #endif
 576                         break;
 577
 578 #if defined(CONFIG_QUOTA)
 579                 case Opt_quota:
 580                 case Opt_usrquota:
 581                         set_opt(sbi->s_mount_opt, USRQUOTA);
 582                         break;
 583
 584                 case Opt_grpquota:
 585                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 586                         break;
 587 #else
 588                 case Opt_quota:
 589                 case Opt_usrquota:
 590                 case Opt_grpquota:
 591                         ext2_msg(sb, KERN_INFO,
 592                                 "quota operations not supported");
 593                         break;
 594 #endif
 595
 596                 case Opt_reservation:
 597                         set_opt(sbi->s_mount_opt, RESERVATION);
 598                         ext2_msg(sb, KERN_INFO, "reservations ON");
 599                         break;
 600                 case Opt_noreservation:
 601                         clear_opt(sbi->s_mount_opt, RESERVATION);
 602                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 603                         break;
 604                 case Opt_ignore:
 605                         break;
 606                 default:
 607                         return 0;
 608                 }
 609         }
 610         return 1;
 611 }
 612
 613 static int ext2_setup_super (struct super_block * sb,
 614                               struct ext2_super_block * es,
 615                               int read_only)
 616 {
 617         int res = 0;
 618         struct ext2_sb_info *sbi = EXT2_SB(sb);
 619
 620         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 621                 ext2_msg(sb, KERN_ERR,
 622                         "error: revision level too high, "
 623                         "forcing read-only mode");
 624                 res = MS_RDONLY;
 625         }
 626         if (read_only)
 627                 return res;
 628         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 629                 ext2_msg(sb, KERN_WARNING,
 630                         "warning: mounting unchecked fs, "
 631                         "running e2fsck is recommended");
 632         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 633                 ext2_msg(sb, KERN_WARNING,
 634                         "warning: mounting fs with errors, "
 635                         "running e2fsck is recommended");
 636         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 637                  le16_to_cpu(es->s_mnt_count) >=
 638                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 639                 ext2_msg(sb, KERN_WARNING,
 640                         "warning: maximal mount count reached, "
 641                         "running e2fsck is recommended");
 642         else if (le32_to_cpu(es->s_checkinterval) &&
 643                 (le32_to_cpu(es->s_lastcheck) +
 644                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 645                 ext2_msg(sb, KERN_WARNING,
 646                         "warning: checktime reached, "
 647                         "running e2fsck is recommended");
 648         if (!le16_to_cpu(es->s_max_mnt_count))
 649                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 650         le16_add_cpu(&es->s_mnt_count, 1);
 651         if (test_opt (sb, DEBUG))
 652                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 653                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 654                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 655                         sbi->s_frag_size,
 656                         sbi->s_groups_count,
 657                         EXT2_BLOCKS_PER_GROUP(sb),
 658                         EXT2_INODES_PER_GROUP(sb),
 659                         sbi->s_mount_opt);
 660         return res;
 661 }
 662
 663 static int ext2_check_descriptors(struct super_block *sb)
 664 {
 665         int i;
 666         struct ext2_sb_info *sbi = EXT2_SB(sb);
 667
 668         ext2_debug ("Checking group descriptors");
 669
 670         for (i = 0; i < sbi->s_groups_count; i++) {
 671                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 672                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 673                 ext2_fsblk_t last_block;
 674
 675                 if (i == sbi->s_groups_count - 1)
 676                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 677                 else
 678                         last_block = first_block +
 679                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 680
 681                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 682                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 683                 {
 684                         ext2_error (sb, "ext2_check_descriptors",
 685                                     "Block bitmap for group %d"
 686                                     " not in group (block %lu)!",
 687                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 688                         return 0;
 689                 }
 690                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 691                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 692                 {
 693                         ext2_error (sb, "ext2_check_descriptors",
 694                                     "Inode bitmap for group %d"
 695                                     " not in group (block %lu)!",
 696                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 697                         return 0;
 698                 }
 699                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 700                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 701                     last_block)
 702                 {
 703                         ext2_error (sb, "ext2_check_descriptors",
 704                                     "Inode table for group %d"
 705                                     " not in group (block %lu)!",
 706                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 707                         return 0;
 708                 }
 709         }
 710         return 1;
 711 }
 712
 713 /*
 714  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 715  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 716  * We need to be 1 filesystem block less than the 2^32 sector limit.
 717  */
 718 static loff_t ext2_max_size(int bits)
 719 {
 720         loff_t res = EXT2_NDIR_BLOCKS;
 721         int meta_blocks;
 722         loff_t upper_limit;
 723
 724         /* This is calculated to be the largest file size for a
 725          * dense, file such that the total number of
 726          * sectors in the file, including data and all indirect blocks,
 727          * does not exceed 2^32 -1
 728          * __u32 i_blocks representing the total number of
 729          * 512 bytes blocks of the file
 730          */
 731         upper_limit = (1LL << 32) - 1;
 732
 733         /* total blocks in file system block size */
 734         upper_limit >>= (bits - 9);
 735
 736
 737         /* indirect blocks */
 738         meta_blocks = 1;
 739         /* double indirect blocks */
 740         meta_blocks += 1 + (1LL << (bits-2));
 741         /* tripple indirect blocks */
 742         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 743
 744         upper_limit -= meta_blocks;
 745         upper_limit <<= bits;
 746
 747         res += 1LL << (bits-2);
 748         res += 1LL << (2*(bits-2));
 749         res += 1LL << (3*(bits-2));
 750         res <<= bits;
 751         if (res > upper_limit)
 752                 res = upper_limit;
 753
 754         if (res > MAX_LFS_FILESIZE)
 755                 res = MAX_LFS_FILESIZE;
 756
 757         return res;
 758 }
 759
 760 static unsigned long descriptor_loc(struct super_block *sb,
 761                                     unsigned long logic_sb_block,
 762                                     int nr)
 763 {
 764         struct ext2_sb_info *sbi = EXT2_SB(sb);
 765         unsigned long bg, first_meta_bg;
 766         int has_super = 0;
 767
 768         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 769
 770         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 771             nr < first_meta_bg)
 772                 return (logic_sb_block + nr + 1);
 773         bg = sbi->s_desc_per_block * nr;
 774         if (ext2_bg_has_super(sb, bg))
 775                 has_super = 1;
 776
 777         return ext2_group_first_block_no(sb, bg) + has_super;
 778 }
 779
 780 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 781 {
 782         struct buffer_head * bh;
 783         struct ext2_sb_info * sbi;
 784         struct ext2_super_block * es;
 785         struct inode *root;
 786         unsigned long block;
 787         unsigned long sb_block = get_sb_block(&data);
 788         unsigned long logic_sb_block;
 789         unsigned long offset = 0;
 790         unsigned long def_mount_opts;
 791         long ret = -EINVAL;
 792         int blocksize = BLOCK_SIZE;
 793         int db_count;
 794         int i, j;
 795         __le32 features;
 796         int err;
 797
 798         err = -ENOMEM;
 799         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 800         if (!sbi)
 801                 goto failed;
 802
 803         sbi->s_blockgroup_lock =
 804                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 805         if (!sbi->s_blockgroup_lock) {
 806                 kfree(sbi);
 807                 goto failed;
 808         }
 809         sb->s_fs_info = sbi;
 810         sbi->s_sb_block = sb_block;
 811
 812         spin_lock_init(&sbi->s_lock);
 813
 814         /*
 815          * See what the current blocksize for the device is, and
 816          * use that as the blocksize.  Otherwise (or if the blocksize
 817          * is smaller than the default) use the default.
 818          * This is important for devices that have a hardware
 819          * sectorsize that is larger than the default.
 820          */
 821         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 822         if (!blocksize) {
 823                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 824                 goto failed_sbi;
 825         }
 826
 827         /*
 828          * If the superblock doesn't start on a hardware sector boundary,
 829          * calculate the offset.
 830          */
 831         if (blocksize != BLOCK_SIZE) {
 832                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 833                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 834         } else {
 835                 logic_sb_block = sb_block;
 836         }
 837
 838         if (!(bh = sb_bread(sb, logic_sb_block))) {
 839                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 840                 goto failed_sbi;
 841         }
 842         /*
 843          * Note: s_es must be initialized as soon as possible because
 844          *       some ext2 macro-instructions depend on its value
 845          */
 846         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 847         sbi->s_es = es;
 848         sb->s_magic = le16_to_cpu(es->s_magic);
 849
 850         if (sb->s_magic != EXT2_SUPER_MAGIC)
 851                 goto cantfind_ext2;
 852
 853         /* Set defaults before we parse the mount options */
 854         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 855         if (def_mount_opts & EXT2_DEFM_DEBUG)
 856                 set_opt(sbi->s_mount_opt, DEBUG);
 857         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 858                 set_opt(sbi->s_mount_opt, GRPID);
 859         if (def_mount_opts & EXT2_DEFM_UID16)
 860                 set_opt(sbi->s_mount_opt, NO_UID32);
 861 #ifdef CONFIG_EXT2_FS_XATTR
 862         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 863                 set_opt(sbi->s_mount_opt, XATTR_USER);
 864 #endif
 865 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 866         if (def_mount_opts & EXT2_DEFM_ACL)
 867                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 868 #endif
 869
 870         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 871                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 872         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 873                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 874         else
 875                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 876
 877         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 878         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 879
 880         set_opt(sbi->s_mount_opt, RESERVATION);
 881
 882         if (!parse_options((char *) data, sb))
 883                 goto failed_mount;
 884
 885         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 886                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 887                  MS_POSIXACL : 0);
 888         sb->s_iflags |= SB_I_CGROUPWB;
 889
 890         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 891             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 892              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 893              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 894                 ext2_msg(sb, KERN_WARNING,
 895                         "warning: feature flags set on rev 0 fs, "
 896                         "running e2fsck is recommended");
 897         /*
 898          * Check feature flags regardless of the revision level, since we
 899          * previously didn't change the revision level when setting the flags,
 900          * so there is a chance incompat flags are set on a rev 0 filesystem.
 901          */
 902         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 903         if (features) {
 904                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 905                        "unsupported optional features (%x)",
 906                         le32_to_cpu(features));
 907                 goto failed_mount;
 908         }
 909         if (!(sb->s_flags & MS_RDONLY) &&
 910             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 911                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 912                        "unsupported optional features (%x)",
 913                        le32_to_cpu(features));
 914                 goto failed_mount;
 915         }
 916
 917         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 918
 919         if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
 920                 if (blocksize != PAGE_SIZE) {
 921                         ext2_msg(sb, KERN_ERR,
 922                                         "error: unsupported blocksize for dax");
 923                         goto failed_mount;
 924                 }
 925                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
 926                         ext2_msg(sb, KERN_ERR,
 927                                         "error: device does not support dax");
 928                         goto failed_mount;
 929                 }
 930         }
 931
 932         /* If the blocksize doesn't match, re-read the thing.. */
 933         if (sb->s_blocksize != blocksize) {
 934                 brelse(bh);
 935
 936                 if (!sb_set_blocksize(sb, blocksize)) {
 937                         ext2_msg(sb, KERN_ERR,
 938                                 "error: bad blocksize %d", blocksize);
 939                         goto failed_sbi;
 940                 }
 941
 942                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 943                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 944                 bh = sb_bread(sb, logic_sb_block);
 945                 if(!bh) {
 946                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 947                                 "superblock on 2nd try");
 948                         goto failed_sbi;
 949                 }
 950                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 951                 sbi->s_es = es;
 952                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 953                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 954                         goto failed_mount;
 955                 }
 956         }
 957
 958         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 959         sb->s_max_links = EXT2_LINK_MAX;
 960
 961         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 962                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 963                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 964         } else {
 965                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 966                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 967                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 968                     !is_power_of_2(sbi->s_inode_size) ||
 969                     (sbi->s_inode_size > blocksize)) {
 970                         ext2_msg(sb, KERN_ERR,
 971                                 "error: unsupported inode size: %d",
 972                                 sbi->s_inode_size);
 973                         goto failed_mount;
 974                 }
 975         }
 976
 977         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 978                                    le32_to_cpu(es->s_log_frag_size);
 979         if (sbi->s_frag_size == 0)
 980                 goto cantfind_ext2;
 981         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 982
 983         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 984         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 985         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 986
 987         if (EXT2_INODE_SIZE(sb) == 0)
 988                 goto cantfind_ext2;
 989         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 990         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 991                 goto cantfind_ext2;
 992         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 993                                         sbi->s_inodes_per_block;
 994         sbi->s_desc_per_block = sb->s_blocksize /
 995                                         sizeof (struct ext2_group_desc);
 996         sbi->s_sbh = bh;
 997         sbi->s_mount_state = le16_to_cpu(es->s_state);
 998         sbi->s_addr_per_block_bits =
 999                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1000         sbi->s_desc_per_block_bits =
1001                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1002
1003         if (sb->s_magic != EXT2_SUPER_MAGIC)
1004                 goto cantfind_ext2;
1005
1006         if (sb->s_blocksize != bh->b_size) {
1007                 if (!silent)
1008                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1009                 goto failed_mount;
1010         }
1011
1012         if (sb->s_blocksize != sbi->s_frag_size) {
1013                 ext2_msg(sb, KERN_ERR,
1014                         "error: fragsize %lu != blocksize %lu"
1015                         "(not supported yet)",
1016                         sbi->s_frag_size, sb->s_blocksize);
1017                 goto failed_mount;
1018         }
1019
1020         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1021                 ext2_msg(sb, KERN_ERR,
1022                         "error: #blocks per group too big: %lu",
1023                         sbi->s_blocks_per_group);
1024                 goto failed_mount;
1025         }
1026         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1027                 ext2_msg(sb, KERN_ERR,
1028                         "error: #fragments per group too big: %lu",
1029                         sbi->s_frags_per_group);
1030                 goto failed_mount;
1031         }
1032         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1033                 ext2_msg(sb, KERN_ERR,
1034                         "error: #inodes per group too big: %lu",
1035                         sbi->s_inodes_per_group);
1036                 goto failed_mount;
1037         }
1038
1039         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1040                 goto cantfind_ext2;
1041         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1042                                 le32_to_cpu(es->s_first_data_block) - 1)
1043                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1044         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1045                    EXT2_DESC_PER_BLOCK(sb);
1046         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1047         if (sbi->s_group_desc == NULL) {
1048                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1049                 goto failed_mount;
1050         }
1051         bgl_lock_init(sbi->s_blockgroup_lock);
1052         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1053         if (!sbi->s_debts) {
1054                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1055                 goto failed_mount_group_desc;
1056         }
1057         for (i = 0; i < db_count; i++) {
1058                 block = descriptor_loc(sb, logic_sb_block, i);
1059                 sbi->s_group_desc[i] = sb_bread(sb, block);
1060                 if (!sbi->s_group_desc[i]) {
1061                         for (j = 0; j < i; j++)
1062                                 brelse (sbi->s_group_desc[j]);
1063                         ext2_msg(sb, KERN_ERR,
1064                                 "error: unable to read group descriptors");
1065                         goto failed_mount_group_desc;
1066                 }
1067         }
1068         if (!ext2_check_descriptors (sb)) {
1069                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1070                 goto failed_mount2;
1071         }
1072         sbi->s_gdb_count = db_count;
1073         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1074         spin_lock_init(&sbi->s_next_gen_lock);
1075
1076         /* per fileystem reservation list head & lock */
1077         spin_lock_init(&sbi->s_rsv_window_lock);
1078         sbi->s_rsv_window_root = RB_ROOT;
1079         /*
1080          * Add a single, static dummy reservation to the start of the
1081          * reservation window list --- it gives us a placeholder for
1082          * append-at-start-of-list which makes the allocation logic
1083          * _much_ simpler.
1084          */
1085         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1086         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1087         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1088         sbi->s_rsv_window_head.rsv_goal_size = 0;
1089         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1090
1091         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1092                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1093         if (!err) {
1094                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1095                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1096         }
1097         if (!err) {
1098                 err = percpu_counter_init(&sbi->s_dirs_counter,
1099                                 ext2_count_dirs(sb), GFP_KERNEL);
1100         }
1101         if (err) {
1102                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1103                 goto failed_mount3;
1104         }
1105         /*
1106          * set up enough so that it can read an inode
1107          */
1108         sb->s_op = &ext2_sops;
1109         sb->s_export_op = &ext2_export_ops;
1110         sb->s_xattr = ext2_xattr_handlers;
1111
1112 #ifdef CONFIG_QUOTA
1113         sb->dq_op = &dquot_operations;
1114         sb->s_qcop = &dquot_quotactl_ops;
1115         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1116 #endif
1117
1118         root = ext2_iget(sb, EXT2_ROOT_INO);
1119         if (IS_ERR(root)) {
1120                 ret = PTR_ERR(root);
1121                 goto failed_mount3;
1122         }
1123         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1124                 iput(root);
1125                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1126                 goto failed_mount3;
1127         }
1128
1129         sb->s_root = d_make_root(root);
1130         if (!sb->s_root) {
1131                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1132                 ret = -ENOMEM;
1133                 goto failed_mount3;
1134         }
1135         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1136                 ext2_msg(sb, KERN_WARNING,
1137                         "warning: mounting ext3 filesystem as ext2");
1138         if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1139                 sb->s_flags |= MS_RDONLY;
1140         ext2_write_super(sb);
1141         return 0;
1142
1143 cantfind_ext2:
1144         if (!silent)
1145                 ext2_msg(sb, KERN_ERR,
1146                         "error: can't find an ext2 filesystem on dev %s.",
1147                         sb->s_id);
1148         goto failed_mount;
1149 failed_mount3:
1150         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1151         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1152         percpu_counter_destroy(&sbi->s_dirs_counter);
1153 failed_mount2:
1154         for (i = 0; i < db_count; i++)
1155                 brelse(sbi->s_group_desc[i]);
1156 failed_mount_group_desc:
1157         kfree(sbi->s_group_desc);
1158         kfree(sbi->s_debts);
1159 failed_mount:
1160         brelse(bh);
1161 failed_sbi:
1162         sb->s_fs_info = NULL;
1163         kfree(sbi->s_blockgroup_lock);
1164         kfree(sbi);
1165 failed:
1166         return ret;
1167 }
1168
1169 static void ext2_clear_super_error(struct super_block *sb)
1170 {
1171         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1172
1173         if (buffer_write_io_error(sbh)) {
1174                 /*
1175                  * Oh, dear.  A previous attempt to write the
1176                  * superblock failed.  This could happen because the
1177                  * USB device was yanked out.  Or it could happen to
1178                  * be a transient write error and maybe the block will
1179                  * be remapped.  Nothing we can do but to retry the
1180                  * write and hope for the best.
1181                  */
1182                 ext2_msg(sb, KERN_ERR,
1183                        "previous I/O error to superblock detected\n");
1184                 clear_buffer_write_io_error(sbh);
1185                 set_buffer_uptodate(sbh);
1186         }
1187 }
1188
1189 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1190                             int wait)
1191 {
1192         ext2_clear_super_error(sb);
1193         spin_lock(&EXT2_SB(sb)->s_lock);
1194         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1195         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1196         es->s_wtime = cpu_to_le32(get_seconds());
1197         /* unlock before we do IO */
1198         spin_unlock(&EXT2_SB(sb)->s_lock);
1199         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1200         if (wait)
1201                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1202 }
1203
1204 /*
1205  * In the second extended file system, it is not necessary to
1206  * write the super block since we use a mapping of the
1207  * disk super block in a buffer.
1208  *
1209  * However, this function is still used to set the fs valid
1210  * flags to 0.  We need to set this flag to 0 since the fs
1211  * may have been checked while mounted and e2fsck may have
1212  * set s_state to EXT2_VALID_FS after some corrections.
1213  */
1214 static int ext2_sync_fs(struct super_block *sb, int wait)
1215 {
1216         struct ext2_sb_info *sbi = EXT2_SB(sb);
1217         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1218
1219         /*
1220          * Write quota structures to quota file, sync_blockdev() will write
1221          * them to disk later
1222          */
1223         dquot_writeback_dquots(sb, -1);
1224
1225         spin_lock(&sbi->s_lock);
1226         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1227                 ext2_debug("setting valid to 0\n");
1228                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1229         }
1230         spin_unlock(&sbi->s_lock);
1231         ext2_sync_super(sb, es, wait);
1232         return 0;
1233 }
1234
1235 static int ext2_freeze(struct super_block *sb)
1236 {
1237         struct ext2_sb_info *sbi = EXT2_SB(sb);
1238
1239         /*
1240          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1241          * because we have unattached inodes and thus filesystem is not fully
1242          * consistent.
1243          */
1244         if (atomic_long_read(&sb->s_remove_count)) {
1245                 ext2_sync_fs(sb, 1);
1246                 return 0;
1247         }
1248         /* Set EXT2_FS_VALID flag */
1249         spin_lock(&sbi->s_lock);
1250         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1251         spin_unlock(&sbi->s_lock);
1252         ext2_sync_super(sb, sbi->s_es, 1);
1253
1254         return 0;
1255 }
1256
1257 static int ext2_unfreeze(struct super_block *sb)
1258 {
1259         /* Just write sb to clear EXT2_VALID_FS flag */
1260         ext2_write_super(sb);
1261
1262         return 0;
1263 }
1264
1265 void ext2_write_super(struct super_block *sb)
1266 {
1267         if (!(sb->s_flags & MS_RDONLY))
1268                 ext2_sync_fs(sb, 1);
1269 }
1270
1271 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1272 {
1273         struct ext2_sb_info * sbi = EXT2_SB(sb);
1274         struct ext2_super_block * es;
1275         struct ext2_mount_options old_opts;
1276         unsigned long old_sb_flags;
1277         int err;
1278
1279         sync_filesystem(sb);
1280         spin_lock(&sbi->s_lock);
1281
1282         /* Store the old options */
1283         old_sb_flags = sb->s_flags;
1284         old_opts.s_mount_opt = sbi->s_mount_opt;
1285         old_opts.s_resuid = sbi->s_resuid;
1286         old_opts.s_resgid = sbi->s_resgid;
1287
1288         /*
1289          * Allow the "check" option to be passed as a remount option.
1290          */
1291         if (!parse_options(data, sb)) {
1292                 err = -EINVAL;
1293                 goto restore_opts;
1294         }
1295
1296         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1297                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1298
1299         es = sbi->s_es;
1300         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1301                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1302                          "dax flag with busy inodes while remounting");
1303                 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1304         }
1305         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1306                 spin_unlock(&sbi->s_lock);
1307                 return 0;
1308         }
1309         if (*flags & MS_RDONLY) {
1310                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1311                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
1312                         spin_unlock(&sbi->s_lock);
1313                         return 0;
1314                 }
1315
1316                 /*
1317                  * OK, we are remounting a valid rw partition rdonly, so set
1318                  * the rdonly flag and then mark the partition as valid again.
1319                  */
1320                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1321                 es->s_mtime = cpu_to_le32(get_seconds());
1322                 spin_unlock(&sbi->s_lock);
1323
1324                 err = dquot_suspend(sb, -1);
1325                 if (err < 0) {
1326                         spin_lock(&sbi->s_lock);
1327                         goto restore_opts;
1328                 }
1329
1330                 ext2_sync_super(sb, es, 1);
1331         } else {
1332                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1333                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1334                 if (ret) {
1335                         ext2_msg(sb, KERN_WARNING,
1336                                 "warning: couldn't remount RDWR because of "
1337                                 "unsupported optional features (%x).",
1338                                 le32_to_cpu(ret));
1339                         err = -EROFS;
1340                         goto restore_opts;
1341                 }
1342                 /*
1343                  * Mounting a RDONLY partition read-write, so reread and
1344                  * store the current valid flag.  (It may have been changed
1345                  * by e2fsck since we originally mounted the partition.)
1346                  */
1347                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1348                 if (!ext2_setup_super (sb, es, 0))
1349                         sb->s_flags &= ~MS_RDONLY;
1350                 spin_unlock(&sbi->s_lock);
1351
1352                 ext2_write_super(sb);
1353
1354                 dquot_resume(sb, -1);
1355         }
1356
1357         return 0;
1358 restore_opts:
1359         sbi->s_mount_opt = old_opts.s_mount_opt;
1360         sbi->s_resuid = old_opts.s_resuid;
1361         sbi->s_resgid = old_opts.s_resgid;
1362         sb->s_flags = old_sb_flags;
1363         spin_unlock(&sbi->s_lock);
1364         return err;
1365 }
1366
1367 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1368 {
1369         struct super_block *sb = dentry->d_sb;
1370         struct ext2_sb_info *sbi = EXT2_SB(sb);
1371         struct ext2_super_block *es = sbi->s_es;
1372         u64 fsid;
1373
1374         spin_lock(&sbi->s_lock);
1375
1376         if (test_opt (sb, MINIX_DF))
1377                 sbi->s_overhead_last = 0;
1378         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1379                 unsigned long i, overhead = 0;
1380                 smp_rmb();
1381
1382                 /*
1383                  * Compute the overhead (FS structures). This is constant
1384                  * for a given filesystem unless the number of block groups
1385                  * changes so we cache the previous value until it does.
1386                  */
1387
1388                 /*
1389                  * All of the blocks before first_data_block are
1390                  * overhead
1391                  */
1392                 overhead = le32_to_cpu(es->s_first_data_block);
1393
1394                 /*
1395                  * Add the overhead attributed to the superblock and
1396                  * block group descriptors.  If the sparse superblocks
1397                  * feature is turned on, then not all groups have this.
1398                  */
1399                 for (i = 0; i < sbi->s_groups_count; i++)
1400                         overhead += ext2_bg_has_super(sb, i) +
1401                                 ext2_bg_num_gdb(sb, i);
1402
1403                 /*
1404                  * Every block group has an inode bitmap, a block
1405                  * bitmap, and an inode table.
1406                  */
1407                 overhead += (sbi->s_groups_count *
1408                              (2 + sbi->s_itb_per_group));
1409                 sbi->s_overhead_last = overhead;
1410                 smp_wmb();
1411                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1412         }
1413
1414         buf->f_type = EXT2_SUPER_MAGIC;
1415         buf->f_bsize = sb->s_blocksize;
1416         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1417         buf->f_bfree = ext2_count_free_blocks(sb);
1418         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1419         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1420         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1421                 buf->f_bavail = 0;
1422         buf->f_files = le32_to_cpu(es->s_inodes_count);
1423         buf->f_ffree = ext2_count_free_inodes(sb);
1424         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1425         buf->f_namelen = EXT2_NAME_LEN;
1426         fsid = le64_to_cpup((void *)es->s_uuid) ^
1427                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1428         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1429         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1430         spin_unlock(&sbi->s_lock);
1431         return 0;
1432 }
1433
1434 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1435         int flags, const char *dev_name, void *data)
1436 {
1437         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1438 }
1439
1440 #ifdef CONFIG_QUOTA
1441
1442 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1443  * acquiring the locks... As quota files are never truncated and quota code
1444  * itself serializes the operations (and no one else should touch the files)
1445  * we don't have to be afraid of races */
1446 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1447                                size_t len, loff_t off)
1448 {
1449         struct inode *inode = sb_dqopt(sb)->files[type];
1450         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1451         int err = 0;
1452         int offset = off & (sb->s_blocksize - 1);
1453         int tocopy;
1454         size_t toread;
1455         struct buffer_head tmp_bh;
1456         struct buffer_head *bh;
1457         loff_t i_size = i_size_read(inode);
1458
1459         if (off > i_size)
1460                 return 0;
1461         if (off+len > i_size)
1462                 len = i_size-off;
1463         toread = len;
1464         while (toread > 0) {
1465                 tocopy = sb->s_blocksize - offset < toread ?
1466                                 sb->s_blocksize - offset : toread;
1467
1468                 tmp_bh.b_state = 0;
1469                 tmp_bh.b_size = sb->s_blocksize;
1470                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1471                 if (err < 0)
1472                         return err;
1473                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1474                         memset(data, 0, tocopy);
1475                 else {
1476                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1477                         if (!bh)
1478                                 return -EIO;
1479                         memcpy(data, bh->b_data+offset, tocopy);
1480                         brelse(bh);
1481                 }
1482                 offset = 0;
1483                 toread -= tocopy;
1484                 data += tocopy;
1485                 blk++;
1486         }
1487         return len;
1488 }
1489
1490 /* Write to quotafile */
1491 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1492                                 const char *data, size_t len, loff_t off)
1493 {
1494         struct inode *inode = sb_dqopt(sb)->files[type];
1495         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1496         int err = 0;
1497         int offset = off & (sb->s_blocksize - 1);
1498         int tocopy;
1499         size_t towrite = len;
1500         struct buffer_head tmp_bh;
1501         struct buffer_head *bh;
1502
1503         while (towrite > 0) {
1504                 tocopy = sb->s_blocksize - offset < towrite ?
1505                                 sb->s_blocksize - offset : towrite;
1506
1507                 tmp_bh.b_state = 0;
1508                 tmp_bh.b_size = sb->s_blocksize;
1509                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1510                 if (err < 0)
1511                         goto out;
1512                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1513                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1514                 else
1515                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1516                 if (unlikely(!bh)) {
1517                         err = -EIO;
1518                         goto out;
1519                 }
1520                 lock_buffer(bh);
1521                 memcpy(bh->b_data+offset, data, tocopy);
1522                 flush_dcache_page(bh->b_page);
1523                 set_buffer_uptodate(bh);
1524                 mark_buffer_dirty(bh);
1525                 unlock_buffer(bh);
1526                 brelse(bh);
1527                 offset = 0;
1528                 towrite -= tocopy;
1529                 data += tocopy;
1530                 blk++;
1531         }
1532 out:
1533         if (len == towrite)
1534                 return err;
1535         if (inode->i_size < off+len-towrite)
1536                 i_size_write(inode, off+len-towrite);
1537         inode->i_version++;
1538         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1539         mark_inode_dirty(inode);
1540         return len - towrite;
1541 }
1542
1543 #endif
1544
1545 static struct file_system_type ext2_fs_type = {
1546         .owner          = THIS_MODULE,
1547         .name           = "ext2",
1548         .mount          = ext2_mount,
1549         .kill_sb        = kill_block_super,
1550         .fs_flags       = FS_REQUIRES_DEV,
1551 };
1552 MODULE_ALIAS_FS("ext2");
1553
1554 static int __init init_ext2_fs(void)
1555 {
1556         int err = init_ext2_xattr();
1557         if (err)
1558                 return err;
1559         err = init_inodecache();
1560         if (err)
1561                 goto out1;
1562         err = register_filesystem(&ext2_fs_type);
1563         if (err)
1564                 goto out;
1565         return 0;
1566 out:
1567         destroy_inodecache();
1568 out1:
1569         exit_ext2_xattr();
1570         return err;
1571 }
1572
1573 static void __exit exit_ext2_fs(void)
1574 {
1575         unregister_filesystem(&ext2_fs_type);
1576         destroy_inodecache();
1577         exit_ext2_xattr();
1578 }
1579
1580 MODULE_AUTHOR("Remy Card and others");
1581 MODULE_DESCRIPTION("Second Extended Filesystem");
1582 MODULE_LICENSE("GPL");
1583 module_init(init_ext2_fs)
1584 module_exit(exit_ext2_fs)