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 <linux/uaccess.h>
  35 #include "ext2.h"
  36 #include "xattr.h"
  37 #include "acl.h"
  38
  39 static void ext2_write_super(struct super_block *sb);
  40 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  41 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  42 static int ext2_sync_fs(struct super_block *sb, int wait);
  43 static int ext2_freeze(struct super_block *sb);
  44 static int ext2_unfreeze(struct super_block *sb);
  45
  46 void ext2_error(struct super_block *sb, const char *function,
  47                 const char *fmt, ...)
  48 {
  49         struct va_format vaf;
  50         va_list args;
  51         struct ext2_sb_info *sbi = EXT2_SB(sb);
  52         struct ext2_super_block *es = sbi->s_es;
  53
  54         if (!(sb->s_flags & MS_RDONLY)) {
  55                 spin_lock(&sbi->s_lock);
  56                 sbi->s_mount_state |= EXT2_ERROR_FS;
  57                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  58                 spin_unlock(&sbi->s_lock);
  59                 ext2_sync_super(sb, es, 1);
  60         }
  61
  62         va_start(args, fmt);
  63
  64         vaf.fmt = fmt;
  65         vaf.va = &args;
  66
  67         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  68                sb->s_id, function, &vaf);
  69
  70         va_end(args);
  71
  72         if (test_opt(sb, ERRORS_PANIC))
  73                 panic("EXT2-fs: panic from previous error\n");
  74         if (test_opt(sb, ERRORS_RO)) {
  75                 ext2_msg(sb, KERN_CRIT,
  76                              "error: remounting filesystem read-only");
  77                 sb->s_flags |= MS_RDONLY;
  78         }
  79 }
  80
  81 void ext2_msg(struct super_block *sb, const char *prefix,
  82                 const char *fmt, ...)
  83 {
  84         struct va_format vaf;
  85         va_list args;
  86
  87         va_start(args, fmt);
  88
  89         vaf.fmt = fmt;
  90         vaf.va = &args;
  91
  92         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  93
  94         va_end(args);
  95 }
  96
  97 /*
  98  * This must be called with sbi->s_lock held.
  99  */
 100 void ext2_update_dynamic_rev(struct super_block *sb)
 101 {
 102         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 103
 104         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 105                 return;
 106
 107         ext2_msg(sb, KERN_WARNING,
 108                      "warning: updating to rev %d because of "
 109                      "new feature flag, running e2fsck is recommended",
 110                      EXT2_DYNAMIC_REV);
 111
 112         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 113         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 114         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 115         /* leave es->s_feature_*compat flags alone */
 116         /* es->s_uuid will be set by e2fsck if empty */
 117
 118         /*
 119          * The rest of the superblock fields should be zero, and if not it
 120          * means they are likely already in use, so leave them alone.  We
 121          * can leave it up to e2fsck to clean up any inconsistencies there.
 122          */
 123 }
 124
 125 #ifdef CONFIG_QUOTA
 126 static int ext2_quota_off(struct super_block *sb, int type);
 127
 128 static void ext2_quota_off_umount(struct super_block *sb)
 129 {
 130         int type;
 131
 132         for (type = 0; type < MAXQUOTAS; type++)
 133                 ext2_quota_off(sb, type);
 134 }
 135 #else
 136 static inline void ext2_quota_off_umount(struct super_block *sb)
 137 {
 138 }
 139 #endif
 140
 141 static void ext2_put_super (struct super_block * sb)
 142 {
 143         int db_count;
 144         int i;
 145         struct ext2_sb_info *sbi = EXT2_SB(sb);
 146
 147         ext2_quota_off_umount(sb);
 148
 149         if (sbi->s_mb_cache) {
 150                 ext2_xattr_destroy_cache(sbi->s_mb_cache);
 151                 sbi->s_mb_cache = NULL;
 152         }
 153         if (!(sb->s_flags & MS_RDONLY)) {
 154                 struct ext2_super_block *es = sbi->s_es;
 155
 156                 spin_lock(&sbi->s_lock);
 157                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 158                 spin_unlock(&sbi->s_lock);
 159                 ext2_sync_super(sb, es, 1);
 160         }
 161         db_count = sbi->s_gdb_count;
 162         for (i = 0; i < db_count; i++)
 163                 if (sbi->s_group_desc[i])
 164                         brelse (sbi->s_group_desc[i]);
 165         kfree(sbi->s_group_desc);
 166         kfree(sbi->s_debts);
 167         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 168         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 169         percpu_counter_destroy(&sbi->s_dirs_counter);
 170         brelse (sbi->s_sbh);
 171         sb->s_fs_info = NULL;
 172         kfree(sbi->s_blockgroup_lock);
 173         kfree(sbi);
 174 }
 175
 176 static struct kmem_cache * ext2_inode_cachep;
 177
 178 static struct inode *ext2_alloc_inode(struct super_block *sb)
 179 {
 180         struct ext2_inode_info *ei;
 181         ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 182         if (!ei)
 183                 return NULL;
 184         ei->i_block_alloc_info = NULL;
 185         ei->vfs_inode.i_version = 1;
 186 #ifdef CONFIG_QUOTA
 187         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 188 #endif
 189
 190         return &ei->vfs_inode;
 191 }
 192
 193 static void ext2_i_callback(struct rcu_head *head)
 194 {
 195         struct inode *inode = container_of(head, struct inode, i_rcu);
 196         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 197 }
 198
 199 static void ext2_destroy_inode(struct inode *inode)
 200 {
 201         call_rcu(&inode->i_rcu, ext2_i_callback);
 202 }
 203
 204 static void init_once(void *foo)
 205 {
 206         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 207
 208         rwlock_init(&ei->i_meta_lock);
 209 #ifdef CONFIG_EXT2_FS_XATTR
 210         init_rwsem(&ei->xattr_sem);
 211 #endif
 212         mutex_init(&ei->truncate_mutex);
 213 #ifdef CONFIG_FS_DAX
 214         init_rwsem(&ei->dax_sem);
 215 #endif
 216         inode_init_once(&ei->vfs_inode);
 217 }
 218
 219 static int __init init_inodecache(void)
 220 {
 221         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 222                                              sizeof(struct ext2_inode_info),
 223                                              0, (SLAB_RECLAIM_ACCOUNT|
 224                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 225                                              init_once);
 226         if (ext2_inode_cachep == NULL)
 227                 return -ENOMEM;
 228         return 0;
 229 }
 230
 231 static void destroy_inodecache(void)
 232 {
 233         /*
 234          * Make sure all delayed rcu free inodes are flushed before we
 235          * destroy cache.
 236          */
 237         rcu_barrier();
 238         kmem_cache_destroy(ext2_inode_cachep);
 239 }
 240
 241 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 242 {
 243         struct super_block *sb = root->d_sb;
 244         struct ext2_sb_info *sbi = EXT2_SB(sb);
 245         struct ext2_super_block *es = sbi->s_es;
 246         unsigned long def_mount_opts;
 247
 248         spin_lock(&sbi->s_lock);
 249         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 250
 251         if (sbi->s_sb_block != 1)
 252                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 253         if (test_opt(sb, MINIX_DF))
 254                 seq_puts(seq, ",minixdf");
 255         if (test_opt(sb, GRPID))
 256                 seq_puts(seq, ",grpid");
 257         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 258                 seq_puts(seq, ",nogrpid");
 259         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 260             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 261                 seq_printf(seq, ",resuid=%u",
 262                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 263         }
 264         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 265             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 266                 seq_printf(seq, ",resgid=%u",
 267                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 268         }
 269         if (test_opt(sb, ERRORS_RO)) {
 270                 int def_errors = le16_to_cpu(es->s_errors);
 271
 272                 if (def_errors == EXT2_ERRORS_PANIC ||
 273                     def_errors == EXT2_ERRORS_CONTINUE) {
 274                         seq_puts(seq, ",errors=remount-ro");
 275                 }
 276         }
 277         if (test_opt(sb, ERRORS_CONT))
 278                 seq_puts(seq, ",errors=continue");
 279         if (test_opt(sb, ERRORS_PANIC))
 280                 seq_puts(seq, ",errors=panic");
 281         if (test_opt(sb, NO_UID32))
 282                 seq_puts(seq, ",nouid32");
 283         if (test_opt(sb, DEBUG))
 284                 seq_puts(seq, ",debug");
 285         if (test_opt(sb, OLDALLOC))
 286                 seq_puts(seq, ",oldalloc");
 287
 288 #ifdef CONFIG_EXT2_FS_XATTR
 289         if (test_opt(sb, XATTR_USER))
 290                 seq_puts(seq, ",user_xattr");
 291         if (!test_opt(sb, XATTR_USER) &&
 292             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 293                 seq_puts(seq, ",nouser_xattr");
 294         }
 295 #endif
 296
 297 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 298         if (test_opt(sb, POSIX_ACL))
 299                 seq_puts(seq, ",acl");
 300         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 301                 seq_puts(seq, ",noacl");
 302 #endif
 303
 304         if (test_opt(sb, NOBH))
 305                 seq_puts(seq, ",nobh");
 306
 307 #if defined(CONFIG_QUOTA)
 308         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 309                 seq_puts(seq, ",usrquota");
 310
 311         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 312                 seq_puts(seq, ",grpquota");
 313 #endif
 314
 315 #ifdef CONFIG_FS_DAX
 316         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 317                 seq_puts(seq, ",xip");
 318         if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
 319                 seq_puts(seq, ",dax");
 320 #endif
 321
 322         if (!test_opt(sb, RESERVATION))
 323                 seq_puts(seq, ",noreservation");
 324
 325         spin_unlock(&sbi->s_lock);
 326         return 0;
 327 }
 328
 329 #ifdef CONFIG_QUOTA
 330 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 331 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 332 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 333                          const struct path *path);
 334 static struct dquot **ext2_get_dquots(struct inode *inode)
 335 {
 336         return EXT2_I(inode)->i_dquot;
 337 }
 338
 339 static const struct quotactl_ops ext2_quotactl_ops = {
 340         .quota_on       = ext2_quota_on,
 341         .quota_off      = ext2_quota_off,
 342         .quota_sync     = dquot_quota_sync,
 343         .get_state      = dquot_get_state,
 344         .set_info       = dquot_set_dqinfo,
 345         .get_dqblk      = dquot_get_dqblk,
 346         .set_dqblk      = dquot_set_dqblk,
 347         .get_nextdqblk  = dquot_get_next_dqblk,
 348 };
 349 #endif
 350
 351 static const struct super_operations ext2_sops = {
 352         .alloc_inode    = ext2_alloc_inode,
 353         .destroy_inode  = ext2_destroy_inode,
 354         .write_inode    = ext2_write_inode,
 355         .evict_inode    = ext2_evict_inode,
 356         .put_super      = ext2_put_super,
 357         .sync_fs        = ext2_sync_fs,
 358         .freeze_fs      = ext2_freeze,
 359         .unfreeze_fs    = ext2_unfreeze,
 360         .statfs         = ext2_statfs,
 361         .remount_fs     = ext2_remount,
 362         .show_options   = ext2_show_options,
 363 #ifdef CONFIG_QUOTA
 364         .quota_read     = ext2_quota_read,
 365         .quota_write    = ext2_quota_write,
 366         .get_dquots     = ext2_get_dquots,
 367 #endif
 368 };
 369
 370 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 371                 u64 ino, u32 generation)
 372 {
 373         struct inode *inode;
 374
 375         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 376                 return ERR_PTR(-ESTALE);
 377         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 378                 return ERR_PTR(-ESTALE);
 379
 380         /*
 381          * ext2_iget isn't quite right if the inode is currently unallocated!
 382          * However ext2_iget currently does appropriate checks to handle stale
 383          * inodes so everything is OK.
 384          */
 385         inode = ext2_iget(sb, ino);
 386         if (IS_ERR(inode))
 387                 return ERR_CAST(inode);
 388         if (generation && inode->i_generation != generation) {
 389                 /* we didn't find the right inode.. */
 390                 iput(inode);
 391                 return ERR_PTR(-ESTALE);
 392         }
 393         return inode;
 394 }
 395
 396 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 397                 int fh_len, int fh_type)
 398 {
 399         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 400                                     ext2_nfs_get_inode);
 401 }
 402
 403 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 404                 int fh_len, int fh_type)
 405 {
 406         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 407                                     ext2_nfs_get_inode);
 408 }
 409
 410 static const struct export_operations ext2_export_ops = {
 411         .fh_to_dentry = ext2_fh_to_dentry,
 412         .fh_to_parent = ext2_fh_to_parent,
 413         .get_parent = ext2_get_parent,
 414 };
 415
 416 static unsigned long get_sb_block(void **data)
 417 {
 418         unsigned long   sb_block;
 419         char            *options = (char *) *data;
 420
 421         if (!options || strncmp(options, "sb=", 3) != 0)
 422                 return 1;       /* Default location */
 423         options += 3;
 424         sb_block = simple_strtoul(options, &options, 0);
 425         if (*options && *options != ',') {
 426                 printk("EXT2-fs: Invalid sb specification: %s\n",
 427                        (char *) *data);
 428                 return 1;
 429         }
 430         if (*options == ',')
 431                 options++;
 432         *data = (void *) options;
 433         return sb_block;
 434 }
 435
 436 enum {
 437         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 438         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 439         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 440         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 441         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 442         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 443 };
 444
 445 static const match_table_t tokens = {
 446         {Opt_bsd_df, "bsddf"},
 447         {Opt_minix_df, "minixdf"},
 448         {Opt_grpid, "grpid"},
 449         {Opt_grpid, "bsdgroups"},
 450         {Opt_nogrpid, "nogrpid"},
 451         {Opt_nogrpid, "sysvgroups"},
 452         {Opt_resgid, "resgid=%u"},
 453         {Opt_resuid, "resuid=%u"},
 454         {Opt_sb, "sb=%u"},
 455         {Opt_err_cont, "errors=continue"},
 456         {Opt_err_panic, "errors=panic"},
 457         {Opt_err_ro, "errors=remount-ro"},
 458         {Opt_nouid32, "nouid32"},
 459         {Opt_nocheck, "check=none"},
 460         {Opt_nocheck, "nocheck"},
 461         {Opt_debug, "debug"},
 462         {Opt_oldalloc, "oldalloc"},
 463         {Opt_orlov, "orlov"},
 464         {Opt_nobh, "nobh"},
 465         {Opt_user_xattr, "user_xattr"},
 466         {Opt_nouser_xattr, "nouser_xattr"},
 467         {Opt_acl, "acl"},
 468         {Opt_noacl, "noacl"},
 469         {Opt_xip, "xip"},
 470         {Opt_dax, "dax"},
 471         {Opt_grpquota, "grpquota"},
 472         {Opt_ignore, "noquota"},
 473         {Opt_quota, "quota"},
 474         {Opt_usrquota, "usrquota"},
 475         {Opt_reservation, "reservation"},
 476         {Opt_noreservation, "noreservation"},
 477         {Opt_err, NULL}
 478 };
 479
 480 static int parse_options(char *options, struct super_block *sb)
 481 {
 482         char *p;
 483         struct ext2_sb_info *sbi = EXT2_SB(sb);
 484         substring_t args[MAX_OPT_ARGS];
 485         int option;
 486         kuid_t uid;
 487         kgid_t gid;
 488
 489         if (!options)
 490                 return 1;
 491
 492         while ((p = strsep (&options, ",")) != NULL) {
 493                 int token;
 494                 if (!*p)
 495                         continue;
 496
 497                 token = match_token(p, tokens, args);
 498                 switch (token) {
 499                 case Opt_bsd_df:
 500                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 501                         break;
 502                 case Opt_minix_df:
 503                         set_opt (sbi->s_mount_opt, MINIX_DF);
 504                         break;
 505                 case Opt_grpid:
 506                         set_opt (sbi->s_mount_opt, GRPID);
 507                         break;
 508                 case Opt_nogrpid:
 509                         clear_opt (sbi->s_mount_opt, GRPID);
 510                         break;
 511                 case Opt_resuid:
 512                         if (match_int(&args[0], &option))
 513                                 return 0;
 514                         uid = make_kuid(current_user_ns(), option);
 515                         if (!uid_valid(uid)) {
 516                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 517                                 return 0;
 518
 519                         }
 520                         sbi->s_resuid = uid;
 521                         break;
 522                 case Opt_resgid:
 523                         if (match_int(&args[0], &option))
 524                                 return 0;
 525                         gid = make_kgid(current_user_ns(), option);
 526                         if (!gid_valid(gid)) {
 527                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 528                                 return 0;
 529                         }
 530                         sbi->s_resgid = gid;
 531                         break;
 532                 case Opt_sb:
 533                         /* handled by get_sb_block() instead of here */
 534                         /* *sb_block = match_int(&args[0]); */
 535                         break;
 536                 case Opt_err_panic:
 537                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 538                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 539                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 540                         break;
 541                 case Opt_err_ro:
 542                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 543                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 544                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 545                         break;
 546                 case Opt_err_cont:
 547                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 548                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 549                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 550                         break;
 551                 case Opt_nouid32:
 552                         set_opt (sbi->s_mount_opt, NO_UID32);
 553                         break;
 554                 case Opt_nocheck:
 555                         clear_opt (sbi->s_mount_opt, CHECK);
 556                         break;
 557                 case Opt_debug:
 558                         set_opt (sbi->s_mount_opt, DEBUG);
 559                         break;
 560                 case Opt_oldalloc:
 561                         set_opt (sbi->s_mount_opt, OLDALLOC);
 562                         break;
 563                 case Opt_orlov:
 564                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 565                         break;
 566                 case Opt_nobh:
 567                         set_opt (sbi->s_mount_opt, NOBH);
 568                         break;
 569 #ifdef CONFIG_EXT2_FS_XATTR
 570                 case Opt_user_xattr:
 571                         set_opt (sbi->s_mount_opt, XATTR_USER);
 572                         break;
 573                 case Opt_nouser_xattr:
 574                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 575                         break;
 576 #else
 577                 case Opt_user_xattr:
 578                 case Opt_nouser_xattr:
 579                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 580                                 "not supported");
 581                         break;
 582 #endif
 583 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 584                 case Opt_acl:
 585                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 586                         break;
 587                 case Opt_noacl:
 588                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 589                         break;
 590 #else
 591                 case Opt_acl:
 592                 case Opt_noacl:
 593                         ext2_msg(sb, KERN_INFO,
 594                                 "(no)acl options not supported");
 595                         break;
 596 #endif
 597                 case Opt_xip:
 598                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 599                         set_opt(sbi->s_mount_opt, XIP);
 600                         /* Fall through */
 601                 case Opt_dax:
 602 #ifdef CONFIG_FS_DAX
 603                         ext2_msg(sb, KERN_WARNING,
 604                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 605                         set_opt(sbi->s_mount_opt, DAX);
 606 #else
 607                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 608 #endif
 609                         break;
 610
 611 #if defined(CONFIG_QUOTA)
 612                 case Opt_quota:
 613                 case Opt_usrquota:
 614                         set_opt(sbi->s_mount_opt, USRQUOTA);
 615                         break;
 616
 617                 case Opt_grpquota:
 618                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 619                         break;
 620 #else
 621                 case Opt_quota:
 622                 case Opt_usrquota:
 623                 case Opt_grpquota:
 624                         ext2_msg(sb, KERN_INFO,
 625                                 "quota operations not supported");
 626                         break;
 627 #endif
 628
 629                 case Opt_reservation:
 630                         set_opt(sbi->s_mount_opt, RESERVATION);
 631                         ext2_msg(sb, KERN_INFO, "reservations ON");
 632                         break;
 633                 case Opt_noreservation:
 634                         clear_opt(sbi->s_mount_opt, RESERVATION);
 635                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 636                         break;
 637                 case Opt_ignore:
 638                         break;
 639                 default:
 640                         return 0;
 641                 }
 642         }
 643         return 1;
 644 }
 645
 646 static int ext2_setup_super (struct super_block * sb,
 647                               struct ext2_super_block * es,
 648                               int read_only)
 649 {
 650         int res = 0;
 651         struct ext2_sb_info *sbi = EXT2_SB(sb);
 652
 653         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 654                 ext2_msg(sb, KERN_ERR,
 655                         "error: revision level too high, "
 656                         "forcing read-only mode");
 657                 res = MS_RDONLY;
 658         }
 659         if (read_only)
 660                 return res;
 661         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 662                 ext2_msg(sb, KERN_WARNING,
 663                         "warning: mounting unchecked fs, "
 664                         "running e2fsck is recommended");
 665         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 666                 ext2_msg(sb, KERN_WARNING,
 667                         "warning: mounting fs with errors, "
 668                         "running e2fsck is recommended");
 669         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 670                  le16_to_cpu(es->s_mnt_count) >=
 671                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 672                 ext2_msg(sb, KERN_WARNING,
 673                         "warning: maximal mount count reached, "
 674                         "running e2fsck is recommended");
 675         else if (le32_to_cpu(es->s_checkinterval) &&
 676                 (le32_to_cpu(es->s_lastcheck) +
 677                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 678                 ext2_msg(sb, KERN_WARNING,
 679                         "warning: checktime reached, "
 680                         "running e2fsck is recommended");
 681         if (!le16_to_cpu(es->s_max_mnt_count))
 682                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 683         le16_add_cpu(&es->s_mnt_count, 1);
 684         if (test_opt (sb, DEBUG))
 685                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 686                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 687                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 688                         sbi->s_frag_size,
 689                         sbi->s_groups_count,
 690                         EXT2_BLOCKS_PER_GROUP(sb),
 691                         EXT2_INODES_PER_GROUP(sb),
 692                         sbi->s_mount_opt);
 693         return res;
 694 }
 695
 696 static int ext2_check_descriptors(struct super_block *sb)
 697 {
 698         int i;
 699         struct ext2_sb_info *sbi = EXT2_SB(sb);
 700
 701         ext2_debug ("Checking group descriptors");
 702
 703         for (i = 0; i < sbi->s_groups_count; i++) {
 704                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 705                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 706                 ext2_fsblk_t last_block;
 707
 708                 if (i == sbi->s_groups_count - 1)
 709                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 710                 else
 711                         last_block = first_block +
 712                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 713
 714                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 715                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 716                 {
 717                         ext2_error (sb, "ext2_check_descriptors",
 718                                     "Block bitmap for group %d"
 719                                     " not in group (block %lu)!",
 720                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 721                         return 0;
 722                 }
 723                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 724                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 725                 {
 726                         ext2_error (sb, "ext2_check_descriptors",
 727                                     "Inode bitmap for group %d"
 728                                     " not in group (block %lu)!",
 729                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 730                         return 0;
 731                 }
 732                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 733                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 734                     last_block)
 735                 {
 736                         ext2_error (sb, "ext2_check_descriptors",
 737                                     "Inode table for group %d"
 738                                     " not in group (block %lu)!",
 739                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 740                         return 0;
 741                 }
 742         }
 743         return 1;
 744 }
 745
 746 /*
 747  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 748  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 749  * We need to be 1 filesystem block less than the 2^32 sector limit.
 750  */
 751 static loff_t ext2_max_size(int bits)
 752 {
 753         loff_t res = EXT2_NDIR_BLOCKS;
 754         int meta_blocks;
 755         loff_t upper_limit;
 756
 757         /* This is calculated to be the largest file size for a
 758          * dense, file such that the total number of
 759          * sectors in the file, including data and all indirect blocks,
 760          * does not exceed 2^32 -1
 761          * __u32 i_blocks representing the total number of
 762          * 512 bytes blocks of the file
 763          */
 764         upper_limit = (1LL << 32) - 1;
 765
 766         /* total blocks in file system block size */
 767         upper_limit >>= (bits - 9);
 768
 769
 770         /* indirect blocks */
 771         meta_blocks = 1;
 772         /* double indirect blocks */
 773         meta_blocks += 1 + (1LL << (bits-2));
 774         /* tripple indirect blocks */
 775         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 776
 777         upper_limit -= meta_blocks;
 778         upper_limit <<= bits;
 779
 780         res += 1LL << (bits-2);
 781         res += 1LL << (2*(bits-2));
 782         res += 1LL << (3*(bits-2));
 783         res <<= bits;
 784         if (res > upper_limit)
 785                 res = upper_limit;
 786
 787         if (res > MAX_LFS_FILESIZE)
 788                 res = MAX_LFS_FILESIZE;
 789
 790         return res;
 791 }
 792
 793 static unsigned long descriptor_loc(struct super_block *sb,
 794                                     unsigned long logic_sb_block,
 795                                     int nr)
 796 {
 797         struct ext2_sb_info *sbi = EXT2_SB(sb);
 798         unsigned long bg, first_meta_bg;
 799         int has_super = 0;
 800
 801         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 802
 803         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 804             nr < first_meta_bg)
 805                 return (logic_sb_block + nr + 1);
 806         bg = sbi->s_desc_per_block * nr;
 807         if (ext2_bg_has_super(sb, bg))
 808                 has_super = 1;
 809
 810         return ext2_group_first_block_no(sb, bg) + has_super;
 811 }
 812
 813 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 814 {
 815         struct buffer_head * bh;
 816         struct ext2_sb_info * sbi;
 817         struct ext2_super_block * es;
 818         struct inode *root;
 819         unsigned long block;
 820         unsigned long sb_block = get_sb_block(&data);
 821         unsigned long logic_sb_block;
 822         unsigned long offset = 0;
 823         unsigned long def_mount_opts;
 824         long ret = -EINVAL;
 825         int blocksize = BLOCK_SIZE;
 826         int db_count;
 827         int i, j;
 828         __le32 features;
 829         int err;
 830
 831         err = -ENOMEM;
 832         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 833         if (!sbi)
 834                 goto failed;
 835
 836         sbi->s_blockgroup_lock =
 837                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 838         if (!sbi->s_blockgroup_lock) {
 839                 kfree(sbi);
 840                 goto failed;
 841         }
 842         sb->s_fs_info = sbi;
 843         sbi->s_sb_block = sb_block;
 844
 845         spin_lock_init(&sbi->s_lock);
 846
 847         /*
 848          * See what the current blocksize for the device is, and
 849          * use that as the blocksize.  Otherwise (or if the blocksize
 850          * is smaller than the default) use the default.
 851          * This is important for devices that have a hardware
 852          * sectorsize that is larger than the default.
 853          */
 854         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 855         if (!blocksize) {
 856                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 857                 goto failed_sbi;
 858         }
 859
 860         /*
 861          * If the superblock doesn't start on a hardware sector boundary,
 862          * calculate the offset.
 863          */
 864         if (blocksize != BLOCK_SIZE) {
 865                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 866                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 867         } else {
 868                 logic_sb_block = sb_block;
 869         }
 870
 871         if (!(bh = sb_bread(sb, logic_sb_block))) {
 872                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 873                 goto failed_sbi;
 874         }
 875         /*
 876          * Note: s_es must be initialized as soon as possible because
 877          *       some ext2 macro-instructions depend on its value
 878          */
 879         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 880         sbi->s_es = es;
 881         sb->s_magic = le16_to_cpu(es->s_magic);
 882
 883         if (sb->s_magic != EXT2_SUPER_MAGIC)
 884                 goto cantfind_ext2;
 885
 886         /* Set defaults before we parse the mount options */
 887         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 888         if (def_mount_opts & EXT2_DEFM_DEBUG)
 889                 set_opt(sbi->s_mount_opt, DEBUG);
 890         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 891                 set_opt(sbi->s_mount_opt, GRPID);
 892         if (def_mount_opts & EXT2_DEFM_UID16)
 893                 set_opt(sbi->s_mount_opt, NO_UID32);
 894 #ifdef CONFIG_EXT2_FS_XATTR
 895         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 896                 set_opt(sbi->s_mount_opt, XATTR_USER);
 897 #endif
 898 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 899         if (def_mount_opts & EXT2_DEFM_ACL)
 900                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 901 #endif
 902
 903         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 904                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 905         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 906                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 907         else
 908                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 909
 910         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 911         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 912
 913         set_opt(sbi->s_mount_opt, RESERVATION);
 914
 915         if (!parse_options((char *) data, sb))
 916                 goto failed_mount;
 917
 918         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 919                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 920                  MS_POSIXACL : 0);
 921         sb->s_iflags |= SB_I_CGROUPWB;
 922
 923         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 924             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 925              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 926              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 927                 ext2_msg(sb, KERN_WARNING,
 928                         "warning: feature flags set on rev 0 fs, "
 929                         "running e2fsck is recommended");
 930         /*
 931          * Check feature flags regardless of the revision level, since we
 932          * previously didn't change the revision level when setting the flags,
 933          * so there is a chance incompat flags are set on a rev 0 filesystem.
 934          */
 935         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 936         if (features) {
 937                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 938                        "unsupported optional features (%x)",
 939                         le32_to_cpu(features));
 940                 goto failed_mount;
 941         }
 942         if (!(sb->s_flags & MS_RDONLY) &&
 943             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 944                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 945                        "unsupported optional features (%x)",
 946                        le32_to_cpu(features));
 947                 goto failed_mount;
 948         }
 949
 950         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 951
 952         if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
 953                 err = bdev_dax_supported(sb, blocksize);
 954                 if (err)
 955                         goto failed_mount;
 956         }
 957
 958         /* If the blocksize doesn't match, re-read the thing.. */
 959         if (sb->s_blocksize != blocksize) {
 960                 brelse(bh);
 961
 962                 if (!sb_set_blocksize(sb, blocksize)) {
 963                         ext2_msg(sb, KERN_ERR,
 964                                 "error: bad blocksize %d", blocksize);
 965                         goto failed_sbi;
 966                 }
 967
 968                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 969                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 970                 bh = sb_bread(sb, logic_sb_block);
 971                 if(!bh) {
 972                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 973                                 "superblock on 2nd try");
 974                         goto failed_sbi;
 975                 }
 976                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 977                 sbi->s_es = es;
 978                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 979                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 980                         goto failed_mount;
 981                 }
 982         }
 983
 984         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 985         sb->s_max_links = EXT2_LINK_MAX;
 986
 987         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 988                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 989                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 990         } else {
 991                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 992                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 993                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 994                     !is_power_of_2(sbi->s_inode_size) ||
 995                     (sbi->s_inode_size > blocksize)) {
 996                         ext2_msg(sb, KERN_ERR,
 997                                 "error: unsupported inode size: %d",
 998                                 sbi->s_inode_size);
 999                         goto failed_mount;
1000                 }
1001         }
1002
1003         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1004                                    le32_to_cpu(es->s_log_frag_size);
1005         if (sbi->s_frag_size == 0)
1006                 goto cantfind_ext2;
1007         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1008
1009         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1010         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1011         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1012
1013         if (EXT2_INODE_SIZE(sb) == 0)
1014                 goto cantfind_ext2;
1015         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1016         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1017                 goto cantfind_ext2;
1018         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1019                                         sbi->s_inodes_per_block;
1020         sbi->s_desc_per_block = sb->s_blocksize /
1021                                         sizeof (struct ext2_group_desc);
1022         sbi->s_sbh = bh;
1023         sbi->s_mount_state = le16_to_cpu(es->s_state);
1024         sbi->s_addr_per_block_bits =
1025                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1026         sbi->s_desc_per_block_bits =
1027                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1028
1029         if (sb->s_magic != EXT2_SUPER_MAGIC)
1030                 goto cantfind_ext2;
1031
1032         if (sb->s_blocksize != bh->b_size) {
1033                 if (!silent)
1034                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1035                 goto failed_mount;
1036         }
1037
1038         if (sb->s_blocksize != sbi->s_frag_size) {
1039                 ext2_msg(sb, KERN_ERR,
1040                         "error: fragsize %lu != blocksize %lu"
1041                         "(not supported yet)",
1042                         sbi->s_frag_size, sb->s_blocksize);
1043                 goto failed_mount;
1044         }
1045
1046         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1047                 ext2_msg(sb, KERN_ERR,
1048                         "error: #blocks per group too big: %lu",
1049                         sbi->s_blocks_per_group);
1050                 goto failed_mount;
1051         }
1052         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1053                 ext2_msg(sb, KERN_ERR,
1054                         "error: #fragments per group too big: %lu",
1055                         sbi->s_frags_per_group);
1056                 goto failed_mount;
1057         }
1058         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1059                 ext2_msg(sb, KERN_ERR,
1060                         "error: #inodes per group too big: %lu",
1061                         sbi->s_inodes_per_group);
1062                 goto failed_mount;
1063         }
1064
1065         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1066                 goto cantfind_ext2;
1067         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1068                                 le32_to_cpu(es->s_first_data_block) - 1)
1069                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1070         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1071                    EXT2_DESC_PER_BLOCK(sb);
1072         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1073         if (sbi->s_group_desc == NULL) {
1074                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1075                 goto failed_mount;
1076         }
1077         bgl_lock_init(sbi->s_blockgroup_lock);
1078         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1079         if (!sbi->s_debts) {
1080                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1081                 goto failed_mount_group_desc;
1082         }
1083         for (i = 0; i < db_count; i++) {
1084                 block = descriptor_loc(sb, logic_sb_block, i);
1085                 sbi->s_group_desc[i] = sb_bread(sb, block);
1086                 if (!sbi->s_group_desc[i]) {
1087                         for (j = 0; j < i; j++)
1088                                 brelse (sbi->s_group_desc[j]);
1089                         ext2_msg(sb, KERN_ERR,
1090                                 "error: unable to read group descriptors");
1091                         goto failed_mount_group_desc;
1092                 }
1093         }
1094         if (!ext2_check_descriptors (sb)) {
1095                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1096                 goto failed_mount2;
1097         }
1098         sbi->s_gdb_count = db_count;
1099         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1100         spin_lock_init(&sbi->s_next_gen_lock);
1101
1102         /* per fileystem reservation list head & lock */
1103         spin_lock_init(&sbi->s_rsv_window_lock);
1104         sbi->s_rsv_window_root = RB_ROOT;
1105         /*
1106          * Add a single, static dummy reservation to the start of the
1107          * reservation window list --- it gives us a placeholder for
1108          * append-at-start-of-list which makes the allocation logic
1109          * _much_ simpler.
1110          */
1111         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1112         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1113         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1114         sbi->s_rsv_window_head.rsv_goal_size = 0;
1115         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1116
1117         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1118                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1119         if (!err) {
1120                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1121                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1122         }
1123         if (!err) {
1124                 err = percpu_counter_init(&sbi->s_dirs_counter,
1125                                 ext2_count_dirs(sb), GFP_KERNEL);
1126         }
1127         if (err) {
1128                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1129                 goto failed_mount3;
1130         }
1131
1132 #ifdef CONFIG_EXT2_FS_XATTR
1133         sbi->s_mb_cache = ext2_xattr_create_cache();
1134         if (!sbi->s_mb_cache) {
1135                 ext2_msg(sb, KERN_ERR, "Failed to create an mb_cache");
1136                 goto failed_mount3;
1137         }
1138 #endif
1139         /*
1140          * set up enough so that it can read an inode
1141          */
1142         sb->s_op = &ext2_sops;
1143         sb->s_export_op = &ext2_export_ops;
1144         sb->s_xattr = ext2_xattr_handlers;
1145
1146 #ifdef CONFIG_QUOTA
1147         sb->dq_op = &dquot_operations;
1148         sb->s_qcop = &ext2_quotactl_ops;
1149         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1150 #endif
1151
1152         root = ext2_iget(sb, EXT2_ROOT_INO);
1153         if (IS_ERR(root)) {
1154                 ret = PTR_ERR(root);
1155                 goto failed_mount3;
1156         }
1157         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1158                 iput(root);
1159                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1160                 goto failed_mount3;
1161         }
1162
1163         sb->s_root = d_make_root(root);
1164         if (!sb->s_root) {
1165                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1166                 ret = -ENOMEM;
1167                 goto failed_mount3;
1168         }
1169         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1170                 ext2_msg(sb, KERN_WARNING,
1171                         "warning: mounting ext3 filesystem as ext2");
1172         if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1173                 sb->s_flags |= MS_RDONLY;
1174         ext2_write_super(sb);
1175         return 0;
1176
1177 cantfind_ext2:
1178         if (!silent)
1179                 ext2_msg(sb, KERN_ERR,
1180                         "error: can't find an ext2 filesystem on dev %s.",
1181                         sb->s_id);
1182         goto failed_mount;
1183 failed_mount3:
1184         if (sbi->s_mb_cache)
1185                 ext2_xattr_destroy_cache(sbi->s_mb_cache);
1186         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1187         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1188         percpu_counter_destroy(&sbi->s_dirs_counter);
1189 failed_mount2:
1190         for (i = 0; i < db_count; i++)
1191                 brelse(sbi->s_group_desc[i]);
1192 failed_mount_group_desc:
1193         kfree(sbi->s_group_desc);
1194         kfree(sbi->s_debts);
1195 failed_mount:
1196         brelse(bh);
1197 failed_sbi:
1198         sb->s_fs_info = NULL;
1199         kfree(sbi->s_blockgroup_lock);
1200         kfree(sbi);
1201 failed:
1202         return ret;
1203 }
1204
1205 static void ext2_clear_super_error(struct super_block *sb)
1206 {
1207         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1208
1209         if (buffer_write_io_error(sbh)) {
1210                 /*
1211                  * Oh, dear.  A previous attempt to write the
1212                  * superblock failed.  This could happen because the
1213                  * USB device was yanked out.  Or it could happen to
1214                  * be a transient write error and maybe the block will
1215                  * be remapped.  Nothing we can do but to retry the
1216                  * write and hope for the best.
1217                  */
1218                 ext2_msg(sb, KERN_ERR,
1219                        "previous I/O error to superblock detected\n");
1220                 clear_buffer_write_io_error(sbh);
1221                 set_buffer_uptodate(sbh);
1222         }
1223 }
1224
1225 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1226                      int wait)
1227 {
1228         ext2_clear_super_error(sb);
1229         spin_lock(&EXT2_SB(sb)->s_lock);
1230         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1231         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1232         es->s_wtime = cpu_to_le32(get_seconds());
1233         /* unlock before we do IO */
1234         spin_unlock(&EXT2_SB(sb)->s_lock);
1235         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1236         if (wait)
1237                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1238 }
1239
1240 /*
1241  * In the second extended file system, it is not necessary to
1242  * write the super block since we use a mapping of the
1243  * disk super block in a buffer.
1244  *
1245  * However, this function is still used to set the fs valid
1246  * flags to 0.  We need to set this flag to 0 since the fs
1247  * may have been checked while mounted and e2fsck may have
1248  * set s_state to EXT2_VALID_FS after some corrections.
1249  */
1250 static int ext2_sync_fs(struct super_block *sb, int wait)
1251 {
1252         struct ext2_sb_info *sbi = EXT2_SB(sb);
1253         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1254
1255         /*
1256          * Write quota structures to quota file, sync_blockdev() will write
1257          * them to disk later
1258          */
1259         dquot_writeback_dquots(sb, -1);
1260
1261         spin_lock(&sbi->s_lock);
1262         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1263                 ext2_debug("setting valid to 0\n");
1264                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1265         }
1266         spin_unlock(&sbi->s_lock);
1267         ext2_sync_super(sb, es, wait);
1268         return 0;
1269 }
1270
1271 static int ext2_freeze(struct super_block *sb)
1272 {
1273         struct ext2_sb_info *sbi = EXT2_SB(sb);
1274
1275         /*
1276          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1277          * because we have unattached inodes and thus filesystem is not fully
1278          * consistent.
1279          */
1280         if (atomic_long_read(&sb->s_remove_count)) {
1281                 ext2_sync_fs(sb, 1);
1282                 return 0;
1283         }
1284         /* Set EXT2_FS_VALID flag */
1285         spin_lock(&sbi->s_lock);
1286         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1287         spin_unlock(&sbi->s_lock);
1288         ext2_sync_super(sb, sbi->s_es, 1);
1289
1290         return 0;
1291 }
1292
1293 static int ext2_unfreeze(struct super_block *sb)
1294 {
1295         /* Just write sb to clear EXT2_VALID_FS flag */
1296         ext2_write_super(sb);
1297
1298         return 0;
1299 }
1300
1301 static void ext2_write_super(struct super_block *sb)
1302 {
1303         if (!(sb->s_flags & MS_RDONLY))
1304                 ext2_sync_fs(sb, 1);
1305 }
1306
1307 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1308 {
1309         struct ext2_sb_info * sbi = EXT2_SB(sb);
1310         struct ext2_super_block * es;
1311         struct ext2_mount_options old_opts;
1312         unsigned long old_sb_flags;
1313         int err;
1314
1315         sync_filesystem(sb);
1316         spin_lock(&sbi->s_lock);
1317
1318         /* Store the old options */
1319         old_sb_flags = sb->s_flags;
1320         old_opts.s_mount_opt = sbi->s_mount_opt;
1321         old_opts.s_resuid = sbi->s_resuid;
1322         old_opts.s_resgid = sbi->s_resgid;
1323
1324         /*
1325          * Allow the "check" option to be passed as a remount option.
1326          */
1327         if (!parse_options(data, sb)) {
1328                 err = -EINVAL;
1329                 goto restore_opts;
1330         }
1331
1332         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1333                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1334
1335         es = sbi->s_es;
1336         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1337                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1338                          "dax flag with busy inodes while remounting");
1339                 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1340         }
1341         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1342                 spin_unlock(&sbi->s_lock);
1343                 return 0;
1344         }
1345         if (*flags & MS_RDONLY) {
1346                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1347                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
1348                         spin_unlock(&sbi->s_lock);
1349                         return 0;
1350                 }
1351
1352                 /*
1353                  * OK, we are remounting a valid rw partition rdonly, so set
1354                  * the rdonly flag and then mark the partition as valid again.
1355                  */
1356                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1357                 es->s_mtime = cpu_to_le32(get_seconds());
1358                 spin_unlock(&sbi->s_lock);
1359
1360                 err = dquot_suspend(sb, -1);
1361                 if (err < 0) {
1362                         spin_lock(&sbi->s_lock);
1363                         goto restore_opts;
1364                 }
1365
1366                 ext2_sync_super(sb, es, 1);
1367         } else {
1368                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1369                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1370                 if (ret) {
1371                         ext2_msg(sb, KERN_WARNING,
1372                                 "warning: couldn't remount RDWR because of "
1373                                 "unsupported optional features (%x).",
1374                                 le32_to_cpu(ret));
1375                         err = -EROFS;
1376                         goto restore_opts;
1377                 }
1378                 /*
1379                  * Mounting a RDONLY partition read-write, so reread and
1380                  * store the current valid flag.  (It may have been changed
1381                  * by e2fsck since we originally mounted the partition.)
1382                  */
1383                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1384                 if (!ext2_setup_super (sb, es, 0))
1385                         sb->s_flags &= ~MS_RDONLY;
1386                 spin_unlock(&sbi->s_lock);
1387
1388                 ext2_write_super(sb);
1389
1390                 dquot_resume(sb, -1);
1391         }
1392
1393         return 0;
1394 restore_opts:
1395         sbi->s_mount_opt = old_opts.s_mount_opt;
1396         sbi->s_resuid = old_opts.s_resuid;
1397         sbi->s_resgid = old_opts.s_resgid;
1398         sb->s_flags = old_sb_flags;
1399         spin_unlock(&sbi->s_lock);
1400         return err;
1401 }
1402
1403 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1404 {
1405         struct super_block *sb = dentry->d_sb;
1406         struct ext2_sb_info *sbi = EXT2_SB(sb);
1407         struct ext2_super_block *es = sbi->s_es;
1408         u64 fsid;
1409
1410         spin_lock(&sbi->s_lock);
1411
1412         if (test_opt (sb, MINIX_DF))
1413                 sbi->s_overhead_last = 0;
1414         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1415                 unsigned long i, overhead = 0;
1416                 smp_rmb();
1417
1418                 /*
1419                  * Compute the overhead (FS structures). This is constant
1420                  * for a given filesystem unless the number of block groups
1421                  * changes so we cache the previous value until it does.
1422                  */
1423
1424                 /*
1425                  * All of the blocks before first_data_block are
1426                  * overhead
1427                  */
1428                 overhead = le32_to_cpu(es->s_first_data_block);
1429
1430                 /*
1431                  * Add the overhead attributed to the superblock and
1432                  * block group descriptors.  If the sparse superblocks
1433                  * feature is turned on, then not all groups have this.
1434                  */
1435                 for (i = 0; i < sbi->s_groups_count; i++)
1436                         overhead += ext2_bg_has_super(sb, i) +
1437                                 ext2_bg_num_gdb(sb, i);
1438
1439                 /*
1440                  * Every block group has an inode bitmap, a block
1441                  * bitmap, and an inode table.
1442                  */
1443                 overhead += (sbi->s_groups_count *
1444                              (2 + sbi->s_itb_per_group));
1445                 sbi->s_overhead_last = overhead;
1446                 smp_wmb();
1447                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1448         }
1449
1450         buf->f_type = EXT2_SUPER_MAGIC;
1451         buf->f_bsize = sb->s_blocksize;
1452         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1453         buf->f_bfree = ext2_count_free_blocks(sb);
1454         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1455         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1456         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1457                 buf->f_bavail = 0;
1458         buf->f_files = le32_to_cpu(es->s_inodes_count);
1459         buf->f_ffree = ext2_count_free_inodes(sb);
1460         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1461         buf->f_namelen = EXT2_NAME_LEN;
1462         fsid = le64_to_cpup((void *)es->s_uuid) ^
1463                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1464         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1465         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1466         spin_unlock(&sbi->s_lock);
1467         return 0;
1468 }
1469
1470 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1471         int flags, const char *dev_name, void *data)
1472 {
1473         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1474 }
1475
1476 #ifdef CONFIG_QUOTA
1477
1478 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1479  * acquiring the locks... As quota files are never truncated and quota code
1480  * itself serializes the operations (and no one else should touch the files)
1481  * we don't have to be afraid of races */
1482 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1483                                size_t len, loff_t off)
1484 {
1485         struct inode *inode = sb_dqopt(sb)->files[type];
1486         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1487         int err = 0;
1488         int offset = off & (sb->s_blocksize - 1);
1489         int tocopy;
1490         size_t toread;
1491         struct buffer_head tmp_bh;
1492         struct buffer_head *bh;
1493         loff_t i_size = i_size_read(inode);
1494
1495         if (off > i_size)
1496                 return 0;
1497         if (off+len > i_size)
1498                 len = i_size-off;
1499         toread = len;
1500         while (toread > 0) {
1501                 tocopy = sb->s_blocksize - offset < toread ?
1502                                 sb->s_blocksize - offset : toread;
1503
1504                 tmp_bh.b_state = 0;
1505                 tmp_bh.b_size = sb->s_blocksize;
1506                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1507                 if (err < 0)
1508                         return err;
1509                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1510                         memset(data, 0, tocopy);
1511                 else {
1512                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1513                         if (!bh)
1514                                 return -EIO;
1515                         memcpy(data, bh->b_data+offset, tocopy);
1516                         brelse(bh);
1517                 }
1518                 offset = 0;
1519                 toread -= tocopy;
1520                 data += tocopy;
1521                 blk++;
1522         }
1523         return len;
1524 }
1525
1526 /* Write to quotafile */
1527 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1528                                 const char *data, size_t len, loff_t off)
1529 {
1530         struct inode *inode = sb_dqopt(sb)->files[type];
1531         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1532         int err = 0;
1533         int offset = off & (sb->s_blocksize - 1);
1534         int tocopy;
1535         size_t towrite = len;
1536         struct buffer_head tmp_bh;
1537         struct buffer_head *bh;
1538
1539         while (towrite > 0) {
1540                 tocopy = sb->s_blocksize - offset < towrite ?
1541                                 sb->s_blocksize - offset : towrite;
1542
1543                 tmp_bh.b_state = 0;
1544                 tmp_bh.b_size = sb->s_blocksize;
1545                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1546                 if (err < 0)
1547                         goto out;
1548                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1549                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1550                 else
1551                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1552                 if (unlikely(!bh)) {
1553                         err = -EIO;
1554                         goto out;
1555                 }
1556                 lock_buffer(bh);
1557                 memcpy(bh->b_data+offset, data, tocopy);
1558                 flush_dcache_page(bh->b_page);
1559                 set_buffer_uptodate(bh);
1560                 mark_buffer_dirty(bh);
1561                 unlock_buffer(bh);
1562                 brelse(bh);
1563                 offset = 0;
1564                 towrite -= tocopy;
1565                 data += tocopy;
1566                 blk++;
1567         }
1568 out:
1569         if (len == towrite)
1570                 return err;
1571         if (inode->i_size < off+len-towrite)
1572                 i_size_write(inode, off+len-towrite);
1573         inode->i_version++;
1574         inode->i_mtime = inode->i_ctime = current_time(inode);
1575         mark_inode_dirty(inode);
1576         return len - towrite;
1577 }
1578
1579 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1580                          const struct path *path)
1581 {
1582         int err;
1583         struct inode *inode;
1584
1585         err = dquot_quota_on(sb, type, format_id, path);
1586         if (err)
1587                 return err;
1588
1589         inode = d_inode(path->dentry);
1590         inode_lock(inode);
1591         EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1592         inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1593                         S_NOATIME | S_IMMUTABLE);
1594         inode_unlock(inode);
1595         mark_inode_dirty(inode);
1596
1597         return 0;
1598 }
1599
1600 static int ext2_quota_off(struct super_block *sb, int type)
1601 {
1602         struct inode *inode = sb_dqopt(sb)->files[type];
1603         int err;
1604
1605         if (!inode || !igrab(inode))
1606                 goto out;
1607
1608         err = dquot_quota_off(sb, type);
1609         if (err)
1610                 goto out_put;
1611
1612         inode_lock(inode);
1613         EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1614         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1615         inode_unlock(inode);
1616         mark_inode_dirty(inode);
1617 out_put:
1618         iput(inode);
1619         return err;
1620 out:
1621         return dquot_quota_off(sb, type);
1622 }
1623
1624 #endif
1625
1626 static struct file_system_type ext2_fs_type = {
1627         .owner          = THIS_MODULE,
1628         .name           = "ext2",
1629         .mount          = ext2_mount,
1630         .kill_sb        = kill_block_super,
1631         .fs_flags       = FS_REQUIRES_DEV,
1632 };
1633 MODULE_ALIAS_FS("ext2");
1634
1635 static int __init init_ext2_fs(void)
1636 {
1637         int err;
1638
1639         err = init_inodecache();
1640         if (err)
1641                 return err;
1642         err = register_filesystem(&ext2_fs_type);
1643         if (err)
1644                 goto out;
1645         return 0;
1646 out:
1647         destroy_inodecache();
1648         return err;
1649 }
1650
1651 static void __exit exit_ext2_fs(void)
1652 {
1653         unregister_filesystem(&ext2_fs_type);
1654         destroy_inodecache();
1655 }
1656
1657 MODULE_AUTHOR("Remy Card and others");
1658 MODULE_DESCRIPTION("Second Extended Filesystem");
1659 MODULE_LICENSE("GPL");
1660 module_init(init_ext2_fs)
1661 module_exit(exit_ext2_fs)