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 <linux/dax.h>
  36 #include "ext2.h"
  37 #include "xattr.h"
  38 #include "acl.h"
  39
  40 static void ext2_write_super(struct super_block *sb);
  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 #ifdef CONFIG_QUOTA
 127 static int ext2_quota_off(struct super_block *sb, int type);
 128
 129 static void ext2_quota_off_umount(struct super_block *sb)
 130 {
 131         int type;
 132
 133         for (type = 0; type < MAXQUOTAS; type++)
 134                 ext2_quota_off(sb, type);
 135 }
 136 #else
 137 static inline void ext2_quota_off_umount(struct super_block *sb)
 138 {
 139 }
 140 #endif
 141
 142 static void ext2_put_super (struct super_block * sb)
 143 {
 144         int db_count;
 145         int i;
 146         struct ext2_sb_info *sbi = EXT2_SB(sb);
 147
 148         ext2_quota_off_umount(sb);
 149
 150         if (sbi->s_mb_cache) {
 151                 ext2_xattr_destroy_cache(sbi->s_mb_cache);
 152                 sbi->s_mb_cache = NULL;
 153         }
 154         if (!(sb->s_flags & MS_RDONLY)) {
 155                 struct ext2_super_block *es = sbi->s_es;
 156
 157                 spin_lock(&sbi->s_lock);
 158                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 159                 spin_unlock(&sbi->s_lock);
 160                 ext2_sync_super(sb, es, 1);
 161         }
 162         db_count = sbi->s_gdb_count;
 163         for (i = 0; i < db_count; i++)
 164                 if (sbi->s_group_desc[i])
 165                         brelse (sbi->s_group_desc[i]);
 166         kfree(sbi->s_group_desc);
 167         kfree(sbi->s_debts);
 168         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 169         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 170         percpu_counter_destroy(&sbi->s_dirs_counter);
 171         brelse (sbi->s_sbh);
 172         sb->s_fs_info = NULL;
 173         kfree(sbi->s_blockgroup_lock);
 174         kfree(sbi);
 175 }
 176
 177 static struct kmem_cache * ext2_inode_cachep;
 178
 179 static struct inode *ext2_alloc_inode(struct super_block *sb)
 180 {
 181         struct ext2_inode_info *ei;
 182         ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 183         if (!ei)
 184                 return NULL;
 185         ei->i_block_alloc_info = NULL;
 186         ei->vfs_inode.i_version = 1;
 187 #ifdef CONFIG_QUOTA
 188         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 189 #endif
 190
 191         return &ei->vfs_inode;
 192 }
 193
 194 static void ext2_i_callback(struct rcu_head *head)
 195 {
 196         struct inode *inode = container_of(head, struct inode, i_rcu);
 197         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 198 }
 199
 200 static void ext2_destroy_inode(struct inode *inode)
 201 {
 202         call_rcu(&inode->i_rcu, ext2_i_callback);
 203 }
 204
 205 static void init_once(void *foo)
 206 {
 207         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 208
 209         rwlock_init(&ei->i_meta_lock);
 210 #ifdef CONFIG_EXT2_FS_XATTR
 211         init_rwsem(&ei->xattr_sem);
 212 #endif
 213         mutex_init(&ei->truncate_mutex);
 214 #ifdef CONFIG_FS_DAX
 215         init_rwsem(&ei->dax_sem);
 216 #endif
 217         inode_init_once(&ei->vfs_inode);
 218 }
 219
 220 static int __init init_inodecache(void)
 221 {
 222         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 223                                              sizeof(struct ext2_inode_info),
 224                                              0, (SLAB_RECLAIM_ACCOUNT|
 225                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 226                                              init_once);
 227         if (ext2_inode_cachep == NULL)
 228                 return -ENOMEM;
 229         return 0;
 230 }
 231
 232 static void destroy_inodecache(void)
 233 {
 234         /*
 235          * Make sure all delayed rcu free inodes are flushed before we
 236          * destroy cache.
 237          */
 238         rcu_barrier();
 239         kmem_cache_destroy(ext2_inode_cachep);
 240 }
 241
 242 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 243 {
 244         struct super_block *sb = root->d_sb;
 245         struct ext2_sb_info *sbi = EXT2_SB(sb);
 246         struct ext2_super_block *es = sbi->s_es;
 247         unsigned long def_mount_opts;
 248
 249         spin_lock(&sbi->s_lock);
 250         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 251
 252         if (sbi->s_sb_block != 1)
 253                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 254         if (test_opt(sb, MINIX_DF))
 255                 seq_puts(seq, ",minixdf");
 256         if (test_opt(sb, GRPID))
 257                 seq_puts(seq, ",grpid");
 258         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 259                 seq_puts(seq, ",nogrpid");
 260         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 261             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 262                 seq_printf(seq, ",resuid=%u",
 263                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 264         }
 265         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 266             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 267                 seq_printf(seq, ",resgid=%u",
 268                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 269         }
 270         if (test_opt(sb, ERRORS_RO)) {
 271                 int def_errors = le16_to_cpu(es->s_errors);
 272
 273                 if (def_errors == EXT2_ERRORS_PANIC ||
 274                     def_errors == EXT2_ERRORS_CONTINUE) {
 275                         seq_puts(seq, ",errors=remount-ro");
 276                 }
 277         }
 278         if (test_opt(sb, ERRORS_CONT))
 279                 seq_puts(seq, ",errors=continue");
 280         if (test_opt(sb, ERRORS_PANIC))
 281                 seq_puts(seq, ",errors=panic");
 282         if (test_opt(sb, NO_UID32))
 283                 seq_puts(seq, ",nouid32");
 284         if (test_opt(sb, DEBUG))
 285                 seq_puts(seq, ",debug");
 286         if (test_opt(sb, OLDALLOC))
 287                 seq_puts(seq, ",oldalloc");
 288
 289 #ifdef CONFIG_EXT2_FS_XATTR
 290         if (test_opt(sb, XATTR_USER))
 291                 seq_puts(seq, ",user_xattr");
 292         if (!test_opt(sb, XATTR_USER) &&
 293             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 294                 seq_puts(seq, ",nouser_xattr");
 295         }
 296 #endif
 297
 298 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 299         if (test_opt(sb, POSIX_ACL))
 300                 seq_puts(seq, ",acl");
 301         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 302                 seq_puts(seq, ",noacl");
 303 #endif
 304
 305         if (test_opt(sb, NOBH))
 306                 seq_puts(seq, ",nobh");
 307
 308 #if defined(CONFIG_QUOTA)
 309         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 310                 seq_puts(seq, ",usrquota");
 311
 312         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 313                 seq_puts(seq, ",grpquota");
 314 #endif
 315
 316 #ifdef CONFIG_FS_DAX
 317         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 318                 seq_puts(seq, ",xip");
 319         if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
 320                 seq_puts(seq, ",dax");
 321 #endif
 322
 323         if (!test_opt(sb, RESERVATION))
 324                 seq_puts(seq, ",noreservation");
 325
 326         spin_unlock(&sbi->s_lock);
 327         return 0;
 328 }
 329
 330 #ifdef CONFIG_QUOTA
 331 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 332 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 333 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 334                          const struct path *path);
 335 static struct dquot **ext2_get_dquots(struct inode *inode)
 336 {
 337         return EXT2_I(inode)->i_dquot;
 338 }
 339
 340 static const struct quotactl_ops ext2_quotactl_ops = {
 341         .quota_on       = ext2_quota_on,
 342         .quota_off      = ext2_quota_off,
 343         .quota_sync     = dquot_quota_sync,
 344         .get_state      = dquot_get_state,
 345         .set_info       = dquot_set_dqinfo,
 346         .get_dqblk      = dquot_get_dqblk,
 347         .set_dqblk      = dquot_set_dqblk,
 348         .get_nextdqblk  = dquot_get_next_dqblk,
 349 };
 350 #endif
 351
 352 static const struct super_operations ext2_sops = {
 353         .alloc_inode    = ext2_alloc_inode,
 354         .destroy_inode  = ext2_destroy_inode,
 355         .write_inode    = ext2_write_inode,
 356         .evict_inode    = ext2_evict_inode,
 357         .put_super      = ext2_put_super,
 358         .sync_fs        = ext2_sync_fs,
 359         .freeze_fs      = ext2_freeze,
 360         .unfreeze_fs    = ext2_unfreeze,
 361         .statfs         = ext2_statfs,
 362         .remount_fs     = ext2_remount,
 363         .show_options   = ext2_show_options,
 364 #ifdef CONFIG_QUOTA
 365         .quota_read     = ext2_quota_read,
 366         .quota_write    = ext2_quota_write,
 367         .get_dquots     = ext2_get_dquots,
 368 #endif
 369 };
 370
 371 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 372                 u64 ino, u32 generation)
 373 {
 374         struct inode *inode;
 375
 376         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 377                 return ERR_PTR(-ESTALE);
 378         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 379                 return ERR_PTR(-ESTALE);
 380
 381         /*
 382          * ext2_iget isn't quite right if the inode is currently unallocated!
 383          * However ext2_iget currently does appropriate checks to handle stale
 384          * inodes so everything is OK.
 385          */
 386         inode = ext2_iget(sb, ino);
 387         if (IS_ERR(inode))
 388                 return ERR_CAST(inode);
 389         if (generation && inode->i_generation != generation) {
 390                 /* we didn't find the right inode.. */
 391                 iput(inode);
 392                 return ERR_PTR(-ESTALE);
 393         }
 394         return inode;
 395 }
 396
 397 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 398                 int fh_len, int fh_type)
 399 {
 400         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 401                                     ext2_nfs_get_inode);
 402 }
 403
 404 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 405                 int fh_len, int fh_type)
 406 {
 407         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 408                                     ext2_nfs_get_inode);
 409 }
 410
 411 static const struct export_operations ext2_export_ops = {
 412         .fh_to_dentry = ext2_fh_to_dentry,
 413         .fh_to_parent = ext2_fh_to_parent,
 414         .get_parent = ext2_get_parent,
 415 };
 416
 417 static unsigned long get_sb_block(void **data)
 418 {
 419         unsigned long   sb_block;
 420         char            *options = (char *) *data;
 421
 422         if (!options || strncmp(options, "sb=", 3) != 0)
 423                 return 1;       /* Default location */
 424         options += 3;
 425         sb_block = simple_strtoul(options, &options, 0);
 426         if (*options && *options != ',') {
 427                 printk("EXT2-fs: Invalid sb specification: %s\n",
 428                        (char *) *data);
 429                 return 1;
 430         }
 431         if (*options == ',')
 432                 options++;
 433         *data = (void *) options;
 434         return sb_block;
 435 }
 436
 437 enum {
 438         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 439         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 440         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 441         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 442         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 443         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 444 };
 445
 446 static const match_table_t tokens = {
 447         {Opt_bsd_df, "bsddf"},
 448         {Opt_minix_df, "minixdf"},
 449         {Opt_grpid, "grpid"},
 450         {Opt_grpid, "bsdgroups"},
 451         {Opt_nogrpid, "nogrpid"},
 452         {Opt_nogrpid, "sysvgroups"},
 453         {Opt_resgid, "resgid=%u"},
 454         {Opt_resuid, "resuid=%u"},
 455         {Opt_sb, "sb=%u"},
 456         {Opt_err_cont, "errors=continue"},
 457         {Opt_err_panic, "errors=panic"},
 458         {Opt_err_ro, "errors=remount-ro"},
 459         {Opt_nouid32, "nouid32"},
 460         {Opt_nocheck, "check=none"},
 461         {Opt_nocheck, "nocheck"},
 462         {Opt_debug, "debug"},
 463         {Opt_oldalloc, "oldalloc"},
 464         {Opt_orlov, "orlov"},
 465         {Opt_nobh, "nobh"},
 466         {Opt_user_xattr, "user_xattr"},
 467         {Opt_nouser_xattr, "nouser_xattr"},
 468         {Opt_acl, "acl"},
 469         {Opt_noacl, "noacl"},
 470         {Opt_xip, "xip"},
 471         {Opt_dax, "dax"},
 472         {Opt_grpquota, "grpquota"},
 473         {Opt_ignore, "noquota"},
 474         {Opt_quota, "quota"},
 475         {Opt_usrquota, "usrquota"},
 476         {Opt_reservation, "reservation"},
 477         {Opt_noreservation, "noreservation"},
 478         {Opt_err, NULL}
 479 };
 480
 481 static int parse_options(char *options, struct super_block *sb)
 482 {
 483         char *p;
 484         struct ext2_sb_info *sbi = EXT2_SB(sb);
 485         substring_t args[MAX_OPT_ARGS];
 486         int option;
 487         kuid_t uid;
 488         kgid_t gid;
 489
 490         if (!options)
 491                 return 1;
 492
 493         while ((p = strsep (&options, ",")) != NULL) {
 494                 int token;
 495                 if (!*p)
 496                         continue;
 497
 498                 token = match_token(p, tokens, args);
 499                 switch (token) {
 500                 case Opt_bsd_df:
 501                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 502                         break;
 503                 case Opt_minix_df:
 504                         set_opt (sbi->s_mount_opt, MINIX_DF);
 505                         break;
 506                 case Opt_grpid:
 507                         set_opt (sbi->s_mount_opt, GRPID);
 508                         break;
 509                 case Opt_nogrpid:
 510                         clear_opt (sbi->s_mount_opt, GRPID);
 511                         break;
 512                 case Opt_resuid:
 513                         if (match_int(&args[0], &option))
 514                                 return 0;
 515                         uid = make_kuid(current_user_ns(), option);
 516                         if (!uid_valid(uid)) {
 517                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 518                                 return 0;
 519
 520                         }
 521                         sbi->s_resuid = uid;
 522                         break;
 523                 case Opt_resgid:
 524                         if (match_int(&args[0], &option))
 525                                 return 0;
 526                         gid = make_kgid(current_user_ns(), option);
 527                         if (!gid_valid(gid)) {
 528                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 529                                 return 0;
 530                         }
 531                         sbi->s_resgid = gid;
 532                         break;
 533                 case Opt_sb:
 534                         /* handled by get_sb_block() instead of here */
 535                         /* *sb_block = match_int(&args[0]); */
 536                         break;
 537                 case Opt_err_panic:
 538                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 539                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 540                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 541                         break;
 542                 case Opt_err_ro:
 543                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 544                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 545                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 546                         break;
 547                 case Opt_err_cont:
 548                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 549                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 550                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 551                         break;
 552                 case Opt_nouid32:
 553                         set_opt (sbi->s_mount_opt, NO_UID32);
 554                         break;
 555                 case Opt_nocheck:
 556                         clear_opt (sbi->s_mount_opt, CHECK);
 557                         break;
 558                 case Opt_debug:
 559                         set_opt (sbi->s_mount_opt, DEBUG);
 560                         break;
 561                 case Opt_oldalloc:
 562                         set_opt (sbi->s_mount_opt, OLDALLOC);
 563                         break;
 564                 case Opt_orlov:
 565                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 566                         break;
 567                 case Opt_nobh:
 568                         set_opt (sbi->s_mount_opt, NOBH);
 569                         break;
 570 #ifdef CONFIG_EXT2_FS_XATTR
 571                 case Opt_user_xattr:
 572                         set_opt (sbi->s_mount_opt, XATTR_USER);
 573                         break;
 574                 case Opt_nouser_xattr:
 575                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 576                         break;
 577 #else
 578                 case Opt_user_xattr:
 579                 case Opt_nouser_xattr:
 580                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 581                                 "not supported");
 582                         break;
 583 #endif
 584 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 585                 case Opt_acl:
 586                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 587                         break;
 588                 case Opt_noacl:
 589                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 590                         break;
 591 #else
 592                 case Opt_acl:
 593                 case Opt_noacl:
 594                         ext2_msg(sb, KERN_INFO,
 595                                 "(no)acl options not supported");
 596                         break;
 597 #endif
 598                 case Opt_xip:
 599                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 600                         set_opt(sbi->s_mount_opt, XIP);
 601                         /* Fall through */
 602                 case Opt_dax:
 603 #ifdef CONFIG_FS_DAX
 604                         ext2_msg(sb, KERN_WARNING,
 605                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 606                         set_opt(sbi->s_mount_opt, DAX);
 607 #else
 608                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 609 #endif
 610                         break;
 611
 612 #if defined(CONFIG_QUOTA)
 613                 case Opt_quota:
 614                 case Opt_usrquota:
 615                         set_opt(sbi->s_mount_opt, USRQUOTA);
 616                         break;
 617
 618                 case Opt_grpquota:
 619                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 620                         break;
 621 #else
 622                 case Opt_quota:
 623                 case Opt_usrquota:
 624                 case Opt_grpquota:
 625                         ext2_msg(sb, KERN_INFO,
 626                                 "quota operations not supported");
 627                         break;
 628 #endif
 629
 630                 case Opt_reservation:
 631                         set_opt(sbi->s_mount_opt, RESERVATION);
 632                         ext2_msg(sb, KERN_INFO, "reservations ON");
 633                         break;
 634                 case Opt_noreservation:
 635                         clear_opt(sbi->s_mount_opt, RESERVATION);
 636                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 637                         break;
 638                 case Opt_ignore:
 639                         break;
 640                 default:
 641                         return 0;
 642                 }
 643         }
 644         return 1;
 645 }
 646
 647 static int ext2_setup_super (struct super_block * sb,
 648                               struct ext2_super_block * es,
 649                               int read_only)
 650 {
 651         int res = 0;
 652         struct ext2_sb_info *sbi = EXT2_SB(sb);
 653
 654         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 655                 ext2_msg(sb, KERN_ERR,
 656                         "error: revision level too high, "
 657                         "forcing read-only mode");
 658                 res = MS_RDONLY;
 659         }
 660         if (read_only)
 661                 return res;
 662         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 663                 ext2_msg(sb, KERN_WARNING,
 664                         "warning: mounting unchecked fs, "
 665                         "running e2fsck is recommended");
 666         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 667                 ext2_msg(sb, KERN_WARNING,
 668                         "warning: mounting fs with errors, "
 669                         "running e2fsck is recommended");
 670         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 671                  le16_to_cpu(es->s_mnt_count) >=
 672                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 673                 ext2_msg(sb, KERN_WARNING,
 674                         "warning: maximal mount count reached, "
 675                         "running e2fsck is recommended");
 676         else if (le32_to_cpu(es->s_checkinterval) &&
 677                 (le32_to_cpu(es->s_lastcheck) +
 678                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 679                 ext2_msg(sb, KERN_WARNING,
 680                         "warning: checktime reached, "
 681                         "running e2fsck is recommended");
 682         if (!le16_to_cpu(es->s_max_mnt_count))
 683                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 684         le16_add_cpu(&es->s_mnt_count, 1);
 685         if (test_opt (sb, DEBUG))
 686                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 687                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 688                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 689                         sbi->s_frag_size,
 690                         sbi->s_groups_count,
 691                         EXT2_BLOCKS_PER_GROUP(sb),
 692                         EXT2_INODES_PER_GROUP(sb),
 693                         sbi->s_mount_opt);
 694         return res;
 695 }
 696
 697 static int ext2_check_descriptors(struct super_block *sb)
 698 {
 699         int i;
 700         struct ext2_sb_info *sbi = EXT2_SB(sb);
 701
 702         ext2_debug ("Checking group descriptors");
 703
 704         for (i = 0; i < sbi->s_groups_count; i++) {
 705                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 706                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 707                 ext2_fsblk_t last_block;
 708
 709                 if (i == sbi->s_groups_count - 1)
 710                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 711                 else
 712                         last_block = first_block +
 713                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 714
 715                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 716                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 717                 {
 718                         ext2_error (sb, "ext2_check_descriptors",
 719                                     "Block bitmap for group %d"
 720                                     " not in group (block %lu)!",
 721                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 722                         return 0;
 723                 }
 724                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 725                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 726                 {
 727                         ext2_error (sb, "ext2_check_descriptors",
 728                                     "Inode bitmap for group %d"
 729                                     " not in group (block %lu)!",
 730                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 731                         return 0;
 732                 }
 733                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 734                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 735                     last_block)
 736                 {
 737                         ext2_error (sb, "ext2_check_descriptors",
 738                                     "Inode table for group %d"
 739                                     " not in group (block %lu)!",
 740                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 741                         return 0;
 742                 }
 743         }
 744         return 1;
 745 }
 746
 747 /*
 748  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 749  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 750  * We need to be 1 filesystem block less than the 2^32 sector limit.
 751  */
 752 static loff_t ext2_max_size(int bits)
 753 {
 754         loff_t res = EXT2_NDIR_BLOCKS;
 755         int meta_blocks;
 756         loff_t upper_limit;
 757
 758         /* This is calculated to be the largest file size for a
 759          * dense, file such that the total number of
 760          * sectors in the file, including data and all indirect blocks,
 761          * does not exceed 2^32 -1
 762          * __u32 i_blocks representing the total number of
 763          * 512 bytes blocks of the file
 764          */
 765         upper_limit = (1LL << 32) - 1;
 766
 767         /* total blocks in file system block size */
 768         upper_limit >>= (bits - 9);
 769
 770
 771         /* indirect blocks */
 772         meta_blocks = 1;
 773         /* double indirect blocks */
 774         meta_blocks += 1 + (1LL << (bits-2));
 775         /* tripple indirect blocks */
 776         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 777
 778         upper_limit -= meta_blocks;
 779         upper_limit <<= bits;
 780
 781         res += 1LL << (bits-2);
 782         res += 1LL << (2*(bits-2));
 783         res += 1LL << (3*(bits-2));
 784         res <<= bits;
 785         if (res > upper_limit)
 786                 res = upper_limit;
 787
 788         if (res > MAX_LFS_FILESIZE)
 789                 res = MAX_LFS_FILESIZE;
 790
 791         return res;
 792 }
 793
 794 static unsigned long descriptor_loc(struct super_block *sb,
 795                                     unsigned long logic_sb_block,
 796                                     int nr)
 797 {
 798         struct ext2_sb_info *sbi = EXT2_SB(sb);
 799         unsigned long bg, first_meta_bg;
 800         int has_super = 0;
 801
 802         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 803
 804         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 805             nr < first_meta_bg)
 806                 return (logic_sb_block + nr + 1);
 807         bg = sbi->s_desc_per_block * nr;
 808         if (ext2_bg_has_super(sb, bg))
 809                 has_super = 1;
 810
 811         return ext2_group_first_block_no(sb, bg) + has_super;
 812 }
 813
 814 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 815 {
 816         struct buffer_head * bh;
 817         struct ext2_sb_info * sbi;
 818         struct ext2_super_block * es;
 819         struct inode *root;
 820         unsigned long block;
 821         unsigned long sb_block = get_sb_block(&data);
 822         unsigned long logic_sb_block;
 823         unsigned long offset = 0;
 824         unsigned long def_mount_opts;
 825         long ret = -EINVAL;
 826         int blocksize = BLOCK_SIZE;
 827         int db_count;
 828         int i, j;
 829         __le32 features;
 830         int err;
 831
 832         err = -ENOMEM;
 833         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 834         if (!sbi)
 835                 goto failed;
 836
 837         sbi->s_blockgroup_lock =
 838                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 839         if (!sbi->s_blockgroup_lock) {
 840                 kfree(sbi);
 841                 goto failed;
 842         }
 843         sb->s_fs_info = sbi;
 844         sbi->s_sb_block = sb_block;
 845
 846         spin_lock_init(&sbi->s_lock);
 847
 848         /*
 849          * See what the current blocksize for the device is, and
 850          * use that as the blocksize.  Otherwise (or if the blocksize
 851          * is smaller than the default) use the default.
 852          * This is important for devices that have a hardware
 853          * sectorsize that is larger than the default.
 854          */
 855         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 856         if (!blocksize) {
 857                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 858                 goto failed_sbi;
 859         }
 860
 861         /*
 862          * If the superblock doesn't start on a hardware sector boundary,
 863          * calculate the offset.
 864          */
 865         if (blocksize != BLOCK_SIZE) {
 866                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 867                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 868         } else {
 869                 logic_sb_block = sb_block;
 870         }
 871
 872         if (!(bh = sb_bread(sb, logic_sb_block))) {
 873                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 874                 goto failed_sbi;
 875         }
 876         /*
 877          * Note: s_es must be initialized as soon as possible because
 878          *       some ext2 macro-instructions depend on its value
 879          */
 880         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 881         sbi->s_es = es;
 882         sb->s_magic = le16_to_cpu(es->s_magic);
 883
 884         if (sb->s_magic != EXT2_SUPER_MAGIC)
 885                 goto cantfind_ext2;
 886
 887         /* Set defaults before we parse the mount options */
 888         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 889         if (def_mount_opts & EXT2_DEFM_DEBUG)
 890                 set_opt(sbi->s_mount_opt, DEBUG);
 891         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 892                 set_opt(sbi->s_mount_opt, GRPID);
 893         if (def_mount_opts & EXT2_DEFM_UID16)
 894                 set_opt(sbi->s_mount_opt, NO_UID32);
 895 #ifdef CONFIG_EXT2_FS_XATTR
 896         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 897                 set_opt(sbi->s_mount_opt, XATTR_USER);
 898 #endif
 899 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 900         if (def_mount_opts & EXT2_DEFM_ACL)
 901                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 902 #endif
 903
 904         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 905                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 906         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 907                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 908         else
 909                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 910
 911         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 912         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 913
 914         set_opt(sbi->s_mount_opt, RESERVATION);
 915
 916         if (!parse_options((char *) data, sb))
 917                 goto failed_mount;
 918
 919         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 920                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 921                  MS_POSIXACL : 0);
 922         sb->s_iflags |= SB_I_CGROUPWB;
 923
 924         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 925             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 926              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 927              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 928                 ext2_msg(sb, KERN_WARNING,
 929                         "warning: feature flags set on rev 0 fs, "
 930                         "running e2fsck is recommended");
 931         /*
 932          * Check feature flags regardless of the revision level, since we
 933          * previously didn't change the revision level when setting the flags,
 934          * so there is a chance incompat flags are set on a rev 0 filesystem.
 935          */
 936         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 937         if (features) {
 938                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 939                        "unsupported optional features (%x)",
 940                         le32_to_cpu(features));
 941                 goto failed_mount;
 942         }
 943         if (!(sb->s_flags & MS_RDONLY) &&
 944             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 945                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 946                        "unsupported optional features (%x)",
 947                        le32_to_cpu(features));
 948                 goto failed_mount;
 949         }
 950
 951         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 952
 953         if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
 954                 err = bdev_dax_supported(sb, blocksize);
 955                 if (err)
 956                         goto failed_mount;
 957         }
 958
 959         /* If the blocksize doesn't match, re-read the thing.. */
 960         if (sb->s_blocksize != blocksize) {
 961                 brelse(bh);
 962
 963                 if (!sb_set_blocksize(sb, blocksize)) {
 964                         ext2_msg(sb, KERN_ERR,
 965                                 "error: bad blocksize %d", blocksize);
 966                         goto failed_sbi;
 967                 }
 968
 969                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 970                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 971                 bh = sb_bread(sb, logic_sb_block);
 972                 if(!bh) {
 973                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 974                                 "superblock on 2nd try");
 975                         goto failed_sbi;
 976                 }
 977                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 978                 sbi->s_es = es;
 979                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 980                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 981                         goto failed_mount;
 982                 }
 983         }
 984
 985         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 986         sb->s_max_links = EXT2_LINK_MAX;
 987
 988         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 989                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 990                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 991         } else {
 992                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 993                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 994                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 995                     !is_power_of_2(sbi->s_inode_size) ||
 996                     (sbi->s_inode_size > blocksize)) {
 997                         ext2_msg(sb, KERN_ERR,
 998                                 "error: unsupported inode size: %d",
 999                                 sbi->s_inode_size);
1000                         goto failed_mount;
1001                 }
1002         }
1003
1004         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1005                                    le32_to_cpu(es->s_log_frag_size);
1006         if (sbi->s_frag_size == 0)
1007                 goto cantfind_ext2;
1008         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1009
1010         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1011         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1012         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1013
1014         if (EXT2_INODE_SIZE(sb) == 0)
1015                 goto cantfind_ext2;
1016         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1017         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1018                 goto cantfind_ext2;
1019         sbi->s_itb_per_group = sbi->s_inodes_per_group /
1020                                         sbi->s_inodes_per_block;
1021         sbi->s_desc_per_block = sb->s_blocksize /
1022                                         sizeof (struct ext2_group_desc);
1023         sbi->s_sbh = bh;
1024         sbi->s_mount_state = le16_to_cpu(es->s_state);
1025         sbi->s_addr_per_block_bits =
1026                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1027         sbi->s_desc_per_block_bits =
1028                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
1029
1030         if (sb->s_magic != EXT2_SUPER_MAGIC)
1031                 goto cantfind_ext2;
1032
1033         if (sb->s_blocksize != bh->b_size) {
1034                 if (!silent)
1035                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1036                 goto failed_mount;
1037         }
1038
1039         if (sb->s_blocksize != sbi->s_frag_size) {
1040                 ext2_msg(sb, KERN_ERR,
1041                         "error: fragsize %lu != blocksize %lu"
1042                         "(not supported yet)",
1043                         sbi->s_frag_size, sb->s_blocksize);
1044                 goto failed_mount;
1045         }
1046
1047         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1048                 ext2_msg(sb, KERN_ERR,
1049                         "error: #blocks per group too big: %lu",
1050                         sbi->s_blocks_per_group);
1051                 goto failed_mount;
1052         }
1053         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1054                 ext2_msg(sb, KERN_ERR,
1055                         "error: #fragments per group too big: %lu",
1056                         sbi->s_frags_per_group);
1057                 goto failed_mount;
1058         }
1059         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1060                 ext2_msg(sb, KERN_ERR,
1061                         "error: #inodes per group too big: %lu",
1062                         sbi->s_inodes_per_group);
1063                 goto failed_mount;
1064         }
1065
1066         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1067                 goto cantfind_ext2;
1068         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1069                                 le32_to_cpu(es->s_first_data_block) - 1)
1070                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1071         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1072                    EXT2_DESC_PER_BLOCK(sb);
1073         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1074         if (sbi->s_group_desc == NULL) {
1075                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1076                 goto failed_mount;
1077         }
1078         bgl_lock_init(sbi->s_blockgroup_lock);
1079         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1080         if (!sbi->s_debts) {
1081                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1082                 goto failed_mount_group_desc;
1083         }
1084         for (i = 0; i < db_count; i++) {
1085                 block = descriptor_loc(sb, logic_sb_block, i);
1086                 sbi->s_group_desc[i] = sb_bread(sb, block);
1087                 if (!sbi->s_group_desc[i]) {
1088                         for (j = 0; j < i; j++)
1089                                 brelse (sbi->s_group_desc[j]);
1090                         ext2_msg(sb, KERN_ERR,
1091                                 "error: unable to read group descriptors");
1092                         goto failed_mount_group_desc;
1093                 }
1094         }
1095         if (!ext2_check_descriptors (sb)) {
1096                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1097                 goto failed_mount2;
1098         }
1099         sbi->s_gdb_count = db_count;
1100         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1101         spin_lock_init(&sbi->s_next_gen_lock);
1102
1103         /* per fileystem reservation list head & lock */
1104         spin_lock_init(&sbi->s_rsv_window_lock);
1105         sbi->s_rsv_window_root = RB_ROOT;
1106         /*
1107          * Add a single, static dummy reservation to the start of the
1108          * reservation window list --- it gives us a placeholder for
1109          * append-at-start-of-list which makes the allocation logic
1110          * _much_ simpler.
1111          */
1112         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1113         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1114         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1115         sbi->s_rsv_window_head.rsv_goal_size = 0;
1116         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1117
1118         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1119                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1120         if (!err) {
1121                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1122                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1123         }
1124         if (!err) {
1125                 err = percpu_counter_init(&sbi->s_dirs_counter,
1126                                 ext2_count_dirs(sb), GFP_KERNEL);
1127         }
1128         if (err) {
1129                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1130                 goto failed_mount3;
1131         }
1132
1133 #ifdef CONFIG_EXT2_FS_XATTR
1134         sbi->s_mb_cache = ext2_xattr_create_cache();
1135         if (!sbi->s_mb_cache) {
1136                 ext2_msg(sb, KERN_ERR, "Failed to create an mb_cache");
1137                 goto failed_mount3;
1138         }
1139 #endif
1140         /*
1141          * set up enough so that it can read an inode
1142          */
1143         sb->s_op = &ext2_sops;
1144         sb->s_export_op = &ext2_export_ops;
1145         sb->s_xattr = ext2_xattr_handlers;
1146
1147 #ifdef CONFIG_QUOTA
1148         sb->dq_op = &dquot_operations;
1149         sb->s_qcop = &ext2_quotactl_ops;
1150         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1151 #endif
1152
1153         root = ext2_iget(sb, EXT2_ROOT_INO);
1154         if (IS_ERR(root)) {
1155                 ret = PTR_ERR(root);
1156                 goto failed_mount3;
1157         }
1158         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1159                 iput(root);
1160                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1161                 goto failed_mount3;
1162         }
1163
1164         sb->s_root = d_make_root(root);
1165         if (!sb->s_root) {
1166                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1167                 ret = -ENOMEM;
1168                 goto failed_mount3;
1169         }
1170         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1171                 ext2_msg(sb, KERN_WARNING,
1172                         "warning: mounting ext3 filesystem as ext2");
1173         if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1174                 sb->s_flags |= MS_RDONLY;
1175         ext2_write_super(sb);
1176         return 0;
1177
1178 cantfind_ext2:
1179         if (!silent)
1180                 ext2_msg(sb, KERN_ERR,
1181                         "error: can't find an ext2 filesystem on dev %s.",
1182                         sb->s_id);
1183         goto failed_mount;
1184 failed_mount3:
1185         if (sbi->s_mb_cache)
1186                 ext2_xattr_destroy_cache(sbi->s_mb_cache);
1187         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1188         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1189         percpu_counter_destroy(&sbi->s_dirs_counter);
1190 failed_mount2:
1191         for (i = 0; i < db_count; i++)
1192                 brelse(sbi->s_group_desc[i]);
1193 failed_mount_group_desc:
1194         kfree(sbi->s_group_desc);
1195         kfree(sbi->s_debts);
1196 failed_mount:
1197         brelse(bh);
1198 failed_sbi:
1199         sb->s_fs_info = NULL;
1200         kfree(sbi->s_blockgroup_lock);
1201         kfree(sbi);
1202 failed:
1203         return ret;
1204 }
1205
1206 static void ext2_clear_super_error(struct super_block *sb)
1207 {
1208         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1209
1210         if (buffer_write_io_error(sbh)) {
1211                 /*
1212                  * Oh, dear.  A previous attempt to write the
1213                  * superblock failed.  This could happen because the
1214                  * USB device was yanked out.  Or it could happen to
1215                  * be a transient write error and maybe the block will
1216                  * be remapped.  Nothing we can do but to retry the
1217                  * write and hope for the best.
1218                  */
1219                 ext2_msg(sb, KERN_ERR,
1220                        "previous I/O error to superblock detected\n");
1221                 clear_buffer_write_io_error(sbh);
1222                 set_buffer_uptodate(sbh);
1223         }
1224 }
1225
1226 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1227                      int wait)
1228 {
1229         ext2_clear_super_error(sb);
1230         spin_lock(&EXT2_SB(sb)->s_lock);
1231         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1232         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1233         es->s_wtime = cpu_to_le32(get_seconds());
1234         /* unlock before we do IO */
1235         spin_unlock(&EXT2_SB(sb)->s_lock);
1236         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1237         if (wait)
1238                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1239 }
1240
1241 /*
1242  * In the second extended file system, it is not necessary to
1243  * write the super block since we use a mapping of the
1244  * disk super block in a buffer.
1245  *
1246  * However, this function is still used to set the fs valid
1247  * flags to 0.  We need to set this flag to 0 since the fs
1248  * may have been checked while mounted and e2fsck may have
1249  * set s_state to EXT2_VALID_FS after some corrections.
1250  */
1251 static int ext2_sync_fs(struct super_block *sb, int wait)
1252 {
1253         struct ext2_sb_info *sbi = EXT2_SB(sb);
1254         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1255
1256         /*
1257          * Write quota structures to quota file, sync_blockdev() will write
1258          * them to disk later
1259          */
1260         dquot_writeback_dquots(sb, -1);
1261
1262         spin_lock(&sbi->s_lock);
1263         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1264                 ext2_debug("setting valid to 0\n");
1265                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1266         }
1267         spin_unlock(&sbi->s_lock);
1268         ext2_sync_super(sb, es, wait);
1269         return 0;
1270 }
1271
1272 static int ext2_freeze(struct super_block *sb)
1273 {
1274         struct ext2_sb_info *sbi = EXT2_SB(sb);
1275
1276         /*
1277          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1278          * because we have unattached inodes and thus filesystem is not fully
1279          * consistent.
1280          */
1281         if (atomic_long_read(&sb->s_remove_count)) {
1282                 ext2_sync_fs(sb, 1);
1283                 return 0;
1284         }
1285         /* Set EXT2_FS_VALID flag */
1286         spin_lock(&sbi->s_lock);
1287         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1288         spin_unlock(&sbi->s_lock);
1289         ext2_sync_super(sb, sbi->s_es, 1);
1290
1291         return 0;
1292 }
1293
1294 static int ext2_unfreeze(struct super_block *sb)
1295 {
1296         /* Just write sb to clear EXT2_VALID_FS flag */
1297         ext2_write_super(sb);
1298
1299         return 0;
1300 }
1301
1302 static void ext2_write_super(struct super_block *sb)
1303 {
1304         if (!(sb->s_flags & MS_RDONLY))
1305                 ext2_sync_fs(sb, 1);
1306 }
1307
1308 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1309 {
1310         struct ext2_sb_info * sbi = EXT2_SB(sb);
1311         struct ext2_super_block * es;
1312         struct ext2_mount_options old_opts;
1313         unsigned long old_sb_flags;
1314         int err;
1315
1316         sync_filesystem(sb);
1317         spin_lock(&sbi->s_lock);
1318
1319         /* Store the old options */
1320         old_sb_flags = sb->s_flags;
1321         old_opts.s_mount_opt = sbi->s_mount_opt;
1322         old_opts.s_resuid = sbi->s_resuid;
1323         old_opts.s_resgid = sbi->s_resgid;
1324
1325         /*
1326          * Allow the "check" option to be passed as a remount option.
1327          */
1328         if (!parse_options(data, sb)) {
1329                 err = -EINVAL;
1330                 goto restore_opts;
1331         }
1332
1333         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1334                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1335
1336         es = sbi->s_es;
1337         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1338                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1339                          "dax flag with busy inodes while remounting");
1340                 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1341         }
1342         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1343                 spin_unlock(&sbi->s_lock);
1344                 return 0;
1345         }
1346         if (*flags & MS_RDONLY) {
1347                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1348                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
1349                         spin_unlock(&sbi->s_lock);
1350                         return 0;
1351                 }
1352
1353                 /*
1354                  * OK, we are remounting a valid rw partition rdonly, so set
1355                  * the rdonly flag and then mark the partition as valid again.
1356                  */
1357                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1358                 es->s_mtime = cpu_to_le32(get_seconds());
1359                 spin_unlock(&sbi->s_lock);
1360
1361                 err = dquot_suspend(sb, -1);
1362                 if (err < 0) {
1363                         spin_lock(&sbi->s_lock);
1364                         goto restore_opts;
1365                 }
1366
1367                 ext2_sync_super(sb, es, 1);
1368         } else {
1369                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1370                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1371                 if (ret) {
1372                         ext2_msg(sb, KERN_WARNING,
1373                                 "warning: couldn't remount RDWR because of "
1374                                 "unsupported optional features (%x).",
1375                                 le32_to_cpu(ret));
1376                         err = -EROFS;
1377                         goto restore_opts;
1378                 }
1379                 /*
1380                  * Mounting a RDONLY partition read-write, so reread and
1381                  * store the current valid flag.  (It may have been changed
1382                  * by e2fsck since we originally mounted the partition.)
1383                  */
1384                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1385                 if (!ext2_setup_super (sb, es, 0))
1386                         sb->s_flags &= ~MS_RDONLY;
1387                 spin_unlock(&sbi->s_lock);
1388
1389                 ext2_write_super(sb);
1390
1391                 dquot_resume(sb, -1);
1392         }
1393
1394         return 0;
1395 restore_opts:
1396         sbi->s_mount_opt = old_opts.s_mount_opt;
1397         sbi->s_resuid = old_opts.s_resuid;
1398         sbi->s_resgid = old_opts.s_resgid;
1399         sb->s_flags = old_sb_flags;
1400         spin_unlock(&sbi->s_lock);
1401         return err;
1402 }
1403
1404 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1405 {
1406         struct super_block *sb = dentry->d_sb;
1407         struct ext2_sb_info *sbi = EXT2_SB(sb);
1408         struct ext2_super_block *es = sbi->s_es;
1409         u64 fsid;
1410
1411         spin_lock(&sbi->s_lock);
1412
1413         if (test_opt (sb, MINIX_DF))
1414                 sbi->s_overhead_last = 0;
1415         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1416                 unsigned long i, overhead = 0;
1417                 smp_rmb();
1418
1419                 /*
1420                  * Compute the overhead (FS structures). This is constant
1421                  * for a given filesystem unless the number of block groups
1422                  * changes so we cache the previous value until it does.
1423                  */
1424
1425                 /*
1426                  * All of the blocks before first_data_block are
1427                  * overhead
1428                  */
1429                 overhead = le32_to_cpu(es->s_first_data_block);
1430
1431                 /*
1432                  * Add the overhead attributed to the superblock and
1433                  * block group descriptors.  If the sparse superblocks
1434                  * feature is turned on, then not all groups have this.
1435                  */
1436                 for (i = 0; i < sbi->s_groups_count; i++)
1437                         overhead += ext2_bg_has_super(sb, i) +
1438                                 ext2_bg_num_gdb(sb, i);
1439
1440                 /*
1441                  * Every block group has an inode bitmap, a block
1442                  * bitmap, and an inode table.
1443                  */
1444                 overhead += (sbi->s_groups_count *
1445                              (2 + sbi->s_itb_per_group));
1446                 sbi->s_overhead_last = overhead;
1447                 smp_wmb();
1448                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1449         }
1450
1451         buf->f_type = EXT2_SUPER_MAGIC;
1452         buf->f_bsize = sb->s_blocksize;
1453         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1454         buf->f_bfree = ext2_count_free_blocks(sb);
1455         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1456         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1457         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1458                 buf->f_bavail = 0;
1459         buf->f_files = le32_to_cpu(es->s_inodes_count);
1460         buf->f_ffree = ext2_count_free_inodes(sb);
1461         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1462         buf->f_namelen = EXT2_NAME_LEN;
1463         fsid = le64_to_cpup((void *)es->s_uuid) ^
1464                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1465         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1466         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1467         spin_unlock(&sbi->s_lock);
1468         return 0;
1469 }
1470
1471 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1472         int flags, const char *dev_name, void *data)
1473 {
1474         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1475 }
1476
1477 #ifdef CONFIG_QUOTA
1478
1479 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1480  * acquiring the locks... As quota files are never truncated and quota code
1481  * itself serializes the operations (and no one else should touch the files)
1482  * we don't have to be afraid of races */
1483 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1484                                size_t len, loff_t off)
1485 {
1486         struct inode *inode = sb_dqopt(sb)->files[type];
1487         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1488         int err = 0;
1489         int offset = off & (sb->s_blocksize - 1);
1490         int tocopy;
1491         size_t toread;
1492         struct buffer_head tmp_bh;
1493         struct buffer_head *bh;
1494         loff_t i_size = i_size_read(inode);
1495
1496         if (off > i_size)
1497                 return 0;
1498         if (off+len > i_size)
1499                 len = i_size-off;
1500         toread = len;
1501         while (toread > 0) {
1502                 tocopy = sb->s_blocksize - offset < toread ?
1503                                 sb->s_blocksize - offset : toread;
1504
1505                 tmp_bh.b_state = 0;
1506                 tmp_bh.b_size = sb->s_blocksize;
1507                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1508                 if (err < 0)
1509                         return err;
1510                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1511                         memset(data, 0, tocopy);
1512                 else {
1513                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1514                         if (!bh)
1515                                 return -EIO;
1516                         memcpy(data, bh->b_data+offset, tocopy);
1517                         brelse(bh);
1518                 }
1519                 offset = 0;
1520                 toread -= tocopy;
1521                 data += tocopy;
1522                 blk++;
1523         }
1524         return len;
1525 }
1526
1527 /* Write to quotafile */
1528 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1529                                 const char *data, size_t len, loff_t off)
1530 {
1531         struct inode *inode = sb_dqopt(sb)->files[type];
1532         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1533         int err = 0;
1534         int offset = off & (sb->s_blocksize - 1);
1535         int tocopy;
1536         size_t towrite = len;
1537         struct buffer_head tmp_bh;
1538         struct buffer_head *bh;
1539
1540         while (towrite > 0) {
1541                 tocopy = sb->s_blocksize - offset < towrite ?
1542                                 sb->s_blocksize - offset : towrite;
1543
1544                 tmp_bh.b_state = 0;
1545                 tmp_bh.b_size = sb->s_blocksize;
1546                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1547                 if (err < 0)
1548                         goto out;
1549                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1550                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1551                 else
1552                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1553                 if (unlikely(!bh)) {
1554                         err = -EIO;
1555                         goto out;
1556                 }
1557                 lock_buffer(bh);
1558                 memcpy(bh->b_data+offset, data, tocopy);
1559                 flush_dcache_page(bh->b_page);
1560                 set_buffer_uptodate(bh);
1561                 mark_buffer_dirty(bh);
1562                 unlock_buffer(bh);
1563                 brelse(bh);
1564                 offset = 0;
1565                 towrite -= tocopy;
1566                 data += tocopy;
1567                 blk++;
1568         }
1569 out:
1570         if (len == towrite)
1571                 return err;
1572         if (inode->i_size < off+len-towrite)
1573                 i_size_write(inode, off+len-towrite);
1574         inode->i_version++;
1575         inode->i_mtime = inode->i_ctime = current_time(inode);
1576         mark_inode_dirty(inode);
1577         return len - towrite;
1578 }
1579
1580 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1581                          const struct path *path)
1582 {
1583         int err;
1584         struct inode *inode;
1585
1586         err = dquot_quota_on(sb, type, format_id, path);
1587         if (err)
1588                 return err;
1589
1590         inode = d_inode(path->dentry);
1591         inode_lock(inode);
1592         EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1593         inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1594                         S_NOATIME | S_IMMUTABLE);
1595         inode_unlock(inode);
1596         mark_inode_dirty(inode);
1597
1598         return 0;
1599 }
1600
1601 static int ext2_quota_off(struct super_block *sb, int type)
1602 {
1603         struct inode *inode = sb_dqopt(sb)->files[type];
1604         int err;
1605
1606         if (!inode || !igrab(inode))
1607                 goto out;
1608
1609         err = dquot_quota_off(sb, type);
1610         if (err)
1611                 goto out_put;
1612
1613         inode_lock(inode);
1614         EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1615         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1616         inode_unlock(inode);
1617         mark_inode_dirty(inode);
1618 out_put:
1619         iput(inode);
1620         return err;
1621 out:
1622         return dquot_quota_off(sb, type);
1623 }
1624
1625 #endif
1626
1627 static struct file_system_type ext2_fs_type = {
1628         .owner          = THIS_MODULE,
1629         .name           = "ext2",
1630         .mount          = ext2_mount,
1631         .kill_sb        = kill_block_super,
1632         .fs_flags       = FS_REQUIRES_DEV,
1633 };
1634 MODULE_ALIAS_FS("ext2");
1635
1636 static int __init init_ext2_fs(void)
1637 {
1638         int err;
1639
1640         err = init_inodecache();
1641         if (err)
1642                 return err;
1643         err = register_filesystem(&ext2_fs_type);
1644         if (err)
1645                 goto out;
1646         return 0;
1647 out:
1648         destroy_inodecache();
1649         return err;
1650 }
1651
1652 static void __exit exit_ext2_fs(void)
1653 {
1654         unregister_filesystem(&ext2_fs_type);
1655         destroy_inodecache();
1656 }
1657
1658 MODULE_AUTHOR("Remy Card and others");
1659 MODULE_DESCRIPTION("Second Extended Filesystem");
1660 MODULE_LICENSE("GPL");
1661 module_init(init_ext2_fs)
1662 module_exit(exit_ext2_fs)