kernel/fs/ext2/super.c

   1 /*
   2  *  linux/fs/ext2/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/slab.h>
  23 #include <linux/init.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/parser.h>
  26 #include <linux/random.h>
  27 #include <linux/buffer_head.h>
  28 #include <linux/exportfs.h>
  29 #include <linux/vfs.h>
  30 #include <linux/seq_file.h>
  31 #include <linux/mount.h>
  32 #include <linux/log2.h>
  33 #include <linux/quotaops.h>
  34 #include <asm/uaccess.h>
  35 #include "ext2.h"
  36 #include "xattr.h"
  37 #include "acl.h"
  38
  39 static void ext2_sync_super(struct super_block *sb,
  40                             struct ext2_super_block *es, int wait);
  41 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  42 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  43 static int ext2_sync_fs(struct super_block *sb, int wait);
  44 static int ext2_freeze(struct super_block *sb);
  45 static int ext2_unfreeze(struct super_block *sb);
  46
  47 void ext2_error(struct super_block *sb, const char *function,
  48                 const char *fmt, ...)
  49 {
  50         struct va_format vaf;
  51         va_list args;
  52         struct ext2_sb_info *sbi = EXT2_SB(sb);
  53         struct ext2_super_block *es = sbi->s_es;
  54
  55         if (!(sb->s_flags & MS_RDONLY)) {
  56                 spin_lock(&sbi->s_lock);
  57                 sbi->s_mount_state |= EXT2_ERROR_FS;
  58                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  59                 spin_unlock(&sbi->s_lock);
  60                 ext2_sync_super(sb, es, 1);
  61         }
  62
  63         va_start(args, fmt);
  64
  65         vaf.fmt = fmt;
  66         vaf.va = &args;
  67
  68         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  69                sb->s_id, function, &vaf);
  70
  71         va_end(args);
  72
  73         if (test_opt(sb, ERRORS_PANIC))
  74                 panic("EXT2-fs: panic from previous error\n");
  75         if (test_opt(sb, ERRORS_RO)) {
  76                 ext2_msg(sb, KERN_CRIT,
  77                              "error: remounting filesystem read-only");
  78                 sb->s_flags |= MS_RDONLY;
  79         }
  80 }
  81
  82 void ext2_msg(struct super_block *sb, const char *prefix,
  83                 const char *fmt, ...)
  84 {
  85         struct va_format vaf;
  86         va_list args;
  87
  88         va_start(args, fmt);
  89
  90         vaf.fmt = fmt;
  91         vaf.va = &args;
  92
  93         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  94
  95         va_end(args);
  96 }
  97
  98 /*
  99  * This must be called with sbi->s_lock held.
 100  */
 101 void ext2_update_dynamic_rev(struct super_block *sb)
 102 {
 103         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 104
 105         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 106                 return;
 107
 108         ext2_msg(sb, KERN_WARNING,
 109                      "warning: updating to rev %d because of "
 110                      "new feature flag, running e2fsck is recommended",
 111                      EXT2_DYNAMIC_REV);
 112
 113         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 114         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 115         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 116         /* leave es->s_feature_*compat flags alone */
 117         /* es->s_uuid will be set by e2fsck if empty */
 118
 119         /*
 120          * The rest of the superblock fields should be zero, and if not it
 121          * means they are likely already in use, so leave them alone.  We
 122          * can leave it up to e2fsck to clean up any inconsistencies there.
 123          */
 124 }
 125
 126 static void ext2_put_super (struct super_block * sb)
 127 {
 128         int db_count;
 129         int i;
 130         struct ext2_sb_info *sbi = EXT2_SB(sb);
 131
 132         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 133
 134         ext2_xattr_put_super(sb);
 135         if (!(sb->s_flags & MS_RDONLY)) {
 136                 struct ext2_super_block *es = sbi->s_es;
 137
 138                 spin_lock(&sbi->s_lock);
 139                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 140                 spin_unlock(&sbi->s_lock);
 141                 ext2_sync_super(sb, es, 1);
 142         }
 143         db_count = sbi->s_gdb_count;
 144         for (i = 0; i < db_count; i++)
 145                 if (sbi->s_group_desc[i])
 146                         brelse (sbi->s_group_desc[i]);
 147         kfree(sbi->s_group_desc);
 148         kfree(sbi->s_debts);
 149         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 150         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 151         percpu_counter_destroy(&sbi->s_dirs_counter);
 152         brelse (sbi->s_sbh);
 153         sb->s_fs_info = NULL;
 154         kfree(sbi->s_blockgroup_lock);
 155         kfree(sbi);
 156 }
 157
 158 static struct kmem_cache * ext2_inode_cachep;
 159
 160 static struct inode *ext2_alloc_inode(struct super_block *sb)
 161 {
 162         struct ext2_inode_info *ei;
 163         ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 164         if (!ei)
 165                 return NULL;
 166         ei->i_block_alloc_info = NULL;
 167         ei->vfs_inode.i_version = 1;
 168 #ifdef CONFIG_QUOTA
 169         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 170 #endif
 171
 172         return &ei->vfs_inode;
 173 }
 174
 175 static void ext2_i_callback(struct rcu_head *head)
 176 {
 177         struct inode *inode = container_of(head, struct inode, i_rcu);
 178         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 179 }
 180
 181 static void ext2_destroy_inode(struct inode *inode)
 182 {
 183         call_rcu(&inode->i_rcu, ext2_i_callback);
 184 }
 185
 186 static void init_once(void *foo)
 187 {
 188         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 189
 190         rwlock_init(&ei->i_meta_lock);
 191 #ifdef CONFIG_EXT2_FS_XATTR
 192         init_rwsem(&ei->xattr_sem);
 193 #endif
 194         mutex_init(&ei->truncate_mutex);
 195         inode_init_once(&ei->vfs_inode);
 196 }
 197
 198 static int __init init_inodecache(void)
 199 {
 200         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 201                                              sizeof(struct ext2_inode_info),
 202                                              0, (SLAB_RECLAIM_ACCOUNT|
 203                                                 SLAB_MEM_SPREAD),
 204                                              init_once);
 205         if (ext2_inode_cachep == NULL)
 206                 return -ENOMEM;
 207         return 0;
 208 }
 209
 210 static void destroy_inodecache(void)
 211 {
 212         /*
 213          * Make sure all delayed rcu free inodes are flushed before we
 214          * destroy cache.
 215          */
 216         rcu_barrier();
 217         kmem_cache_destroy(ext2_inode_cachep);
 218 }
 219
 220 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 221 {
 222         struct super_block *sb = root->d_sb;
 223         struct ext2_sb_info *sbi = EXT2_SB(sb);
 224         struct ext2_super_block *es = sbi->s_es;
 225         unsigned long def_mount_opts;
 226
 227         spin_lock(&sbi->s_lock);
 228         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 229
 230         if (sbi->s_sb_block != 1)
 231                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 232         if (test_opt(sb, MINIX_DF))
 233                 seq_puts(seq, ",minixdf");
 234         if (test_opt(sb, GRPID))
 235                 seq_puts(seq, ",grpid");
 236         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 237                 seq_puts(seq, ",nogrpid");
 238         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 239             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 240                 seq_printf(seq, ",resuid=%u",
 241                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 242         }
 243         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 244             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 245                 seq_printf(seq, ",resgid=%u",
 246                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 247         }
 248         if (test_opt(sb, ERRORS_RO)) {
 249                 int def_errors = le16_to_cpu(es->s_errors);
 250
 251                 if (def_errors == EXT2_ERRORS_PANIC ||
 252                     def_errors == EXT2_ERRORS_CONTINUE) {
 253                         seq_puts(seq, ",errors=remount-ro");
 254                 }
 255         }
 256         if (test_opt(sb, ERRORS_CONT))
 257                 seq_puts(seq, ",errors=continue");
 258         if (test_opt(sb, ERRORS_PANIC))
 259                 seq_puts(seq, ",errors=panic");
 260         if (test_opt(sb, NO_UID32))
 261                 seq_puts(seq, ",nouid32");
 262         if (test_opt(sb, DEBUG))
 263                 seq_puts(seq, ",debug");
 264         if (test_opt(sb, OLDALLOC))
 265                 seq_puts(seq, ",oldalloc");
 266
 267 #ifdef CONFIG_EXT2_FS_XATTR
 268         if (test_opt(sb, XATTR_USER))
 269                 seq_puts(seq, ",user_xattr");
 270         if (!test_opt(sb, XATTR_USER) &&
 271             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 272                 seq_puts(seq, ",nouser_xattr");
 273         }
 274 #endif
 275
 276 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 277         if (test_opt(sb, POSIX_ACL))
 278                 seq_puts(seq, ",acl");
 279         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 280                 seq_puts(seq, ",noacl");
 281 #endif
 282
 283         if (test_opt(sb, NOBH))
 284                 seq_puts(seq, ",nobh");
 285
 286 #if defined(CONFIG_QUOTA)
 287         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 288                 seq_puts(seq, ",usrquota");
 289
 290         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 291                 seq_puts(seq, ",grpquota");
 292 #endif
 293
 294 #ifdef CONFIG_FS_DAX
 295         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 296                 seq_puts(seq, ",xip");
 297         if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
 298                 seq_puts(seq, ",dax");
 299 #endif
 300
 301         if (!test_opt(sb, RESERVATION))
 302                 seq_puts(seq, ",noreservation");
 303
 304         spin_unlock(&sbi->s_lock);
 305         return 0;
 306 }
 307
 308 #ifdef CONFIG_QUOTA
 309 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 310 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 311 static struct dquot **ext2_get_dquots(struct inode *inode)
 312 {
 313         return EXT2_I(inode)->i_dquot;
 314 }
 315 #endif
 316
 317 static const struct super_operations ext2_sops = {
 318         .alloc_inode    = ext2_alloc_inode,
 319         .destroy_inode  = ext2_destroy_inode,
 320         .write_inode    = ext2_write_inode,
 321         .evict_inode    = ext2_evict_inode,
 322         .put_super      = ext2_put_super,
 323         .sync_fs        = ext2_sync_fs,
 324         .freeze_fs      = ext2_freeze,
 325         .unfreeze_fs    = ext2_unfreeze,
 326         .statfs         = ext2_statfs,
 327         .remount_fs     = ext2_remount,
 328         .show_options   = ext2_show_options,
 329 #ifdef CONFIG_QUOTA
 330         .quota_read     = ext2_quota_read,
 331         .quota_write    = ext2_quota_write,
 332         .get_dquots     = ext2_get_dquots,
 333 #endif
 334 };
 335
 336 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 337                 u64 ino, u32 generation)
 338 {
 339         struct inode *inode;
 340
 341         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 342                 return ERR_PTR(-ESTALE);
 343         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 344                 return ERR_PTR(-ESTALE);
 345
 346         /*
 347          * ext2_iget isn't quite right if the inode is currently unallocated!
 348          * However ext2_iget currently does appropriate checks to handle stale
 349          * inodes so everything is OK.
 350          */
 351         inode = ext2_iget(sb, ino);
 352         if (IS_ERR(inode))
 353                 return ERR_CAST(inode);
 354         if (generation && inode->i_generation != generation) {
 355                 /* we didn't find the right inode.. */
 356                 iput(inode);
 357                 return ERR_PTR(-ESTALE);
 358         }
 359         return inode;
 360 }
 361
 362 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 363                 int fh_len, int fh_type)
 364 {
 365         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 366                                     ext2_nfs_get_inode);
 367 }
 368
 369 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 370                 int fh_len, int fh_type)
 371 {
 372         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 373                                     ext2_nfs_get_inode);
 374 }
 375
 376 static const struct export_operations ext2_export_ops = {
 377         .fh_to_dentry = ext2_fh_to_dentry,
 378         .fh_to_parent = ext2_fh_to_parent,
 379         .get_parent = ext2_get_parent,
 380 };
 381
 382 static unsigned long get_sb_block(void **data)
 383 {
 384         unsigned long   sb_block;
 385         char            *options = (char *) *data;
 386
 387         if (!options || strncmp(options, "sb=", 3) != 0)
 388                 return 1;       /* Default location */
 389         options += 3;
 390         sb_block = simple_strtoul(options, &options, 0);
 391         if (*options && *options != ',') {
 392                 printk("EXT2-fs: Invalid sb specification: %s\n",
 393                        (char *) *data);
 394                 return 1;
 395         }
 396         if (*options == ',')
 397                 options++;
 398         *data = (void *) options;
 399         return sb_block;
 400 }
 401
 402 enum {
 403         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 404         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 405         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 406         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 407         Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 408         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 409 };
 410
 411 static const match_table_t tokens = {
 412         {Opt_bsd_df, "bsddf"},
 413         {Opt_minix_df, "minixdf"},
 414         {Opt_grpid, "grpid"},
 415         {Opt_grpid, "bsdgroups"},
 416         {Opt_nogrpid, "nogrpid"},
 417         {Opt_nogrpid, "sysvgroups"},
 418         {Opt_resgid, "resgid=%u"},
 419         {Opt_resuid, "resuid=%u"},
 420         {Opt_sb, "sb=%u"},
 421         {Opt_err_cont, "errors=continue"},
 422         {Opt_err_panic, "errors=panic"},
 423         {Opt_err_ro, "errors=remount-ro"},
 424         {Opt_nouid32, "nouid32"},
 425         {Opt_nocheck, "check=none"},
 426         {Opt_nocheck, "nocheck"},
 427         {Opt_debug, "debug"},
 428         {Opt_oldalloc, "oldalloc"},
 429         {Opt_orlov, "orlov"},
 430         {Opt_nobh, "nobh"},
 431         {Opt_user_xattr, "user_xattr"},
 432         {Opt_nouser_xattr, "nouser_xattr"},
 433         {Opt_acl, "acl"},
 434         {Opt_noacl, "noacl"},
 435         {Opt_xip, "xip"},
 436         {Opt_dax, "dax"},
 437         {Opt_grpquota, "grpquota"},
 438         {Opt_ignore, "noquota"},
 439         {Opt_quota, "quota"},
 440         {Opt_usrquota, "usrquota"},
 441         {Opt_reservation, "reservation"},
 442         {Opt_noreservation, "noreservation"},
 443         {Opt_err, NULL}
 444 };
 445
 446 static int parse_options(char *options, struct super_block *sb)
 447 {
 448         char *p;
 449         struct ext2_sb_info *sbi = EXT2_SB(sb);
 450         substring_t args[MAX_OPT_ARGS];
 451         int option;
 452         kuid_t uid;
 453         kgid_t gid;
 454
 455         if (!options)
 456                 return 1;
 457
 458         while ((p = strsep (&options, ",")) != NULL) {
 459                 int token;
 460                 if (!*p)
 461                         continue;
 462
 463                 token = match_token(p, tokens, args);
 464                 switch (token) {
 465                 case Opt_bsd_df:
 466                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 467                         break;
 468                 case Opt_minix_df:
 469                         set_opt (sbi->s_mount_opt, MINIX_DF);
 470                         break;
 471                 case Opt_grpid:
 472                         set_opt (sbi->s_mount_opt, GRPID);
 473                         break;
 474                 case Opt_nogrpid:
 475                         clear_opt (sbi->s_mount_opt, GRPID);
 476                         break;
 477                 case Opt_resuid:
 478                         if (match_int(&args[0], &option))
 479                                 return 0;
 480                         uid = make_kuid(current_user_ns(), option);
 481                         if (!uid_valid(uid)) {
 482                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 483                                 return 0;
 484
 485                         }
 486                         sbi->s_resuid = uid;
 487                         break;
 488                 case Opt_resgid:
 489                         if (match_int(&args[0], &option))
 490                                 return 0;
 491                         gid = make_kgid(current_user_ns(), option);
 492                         if (!gid_valid(gid)) {
 493                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 494                                 return 0;
 495                         }
 496                         sbi->s_resgid = gid;
 497                         break;
 498                 case Opt_sb:
 499                         /* handled by get_sb_block() instead of here */
 500                         /* *sb_block = match_int(&args[0]); */
 501                         break;
 502                 case Opt_err_panic:
 503                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 504                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 505                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 506                         break;
 507                 case Opt_err_ro:
 508                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 509                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 510                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 511                         break;
 512                 case Opt_err_cont:
 513                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 514                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 515                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 516                         break;
 517                 case Opt_nouid32:
 518                         set_opt (sbi->s_mount_opt, NO_UID32);
 519                         break;
 520                 case Opt_nocheck:
 521                         clear_opt (sbi->s_mount_opt, CHECK);
 522                         break;
 523                 case Opt_debug:
 524                         set_opt (sbi->s_mount_opt, DEBUG);
 525                         break;
 526                 case Opt_oldalloc:
 527                         set_opt (sbi->s_mount_opt, OLDALLOC);
 528                         break;
 529                 case Opt_orlov:
 530                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 531                         break;
 532                 case Opt_nobh:
 533                         set_opt (sbi->s_mount_opt, NOBH);
 534                         break;
 535 #ifdef CONFIG_EXT2_FS_XATTR
 536                 case Opt_user_xattr:
 537                         set_opt (sbi->s_mount_opt, XATTR_USER);
 538                         break;
 539                 case Opt_nouser_xattr:
 540                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 541                         break;
 542 #else
 543                 case Opt_user_xattr:
 544                 case Opt_nouser_xattr:
 545                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 546                                 "not supported");
 547                         break;
 548 #endif
 549 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 550                 case Opt_acl:
 551                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 552                         break;
 553                 case Opt_noacl:
 554                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 555                         break;
 556 #else
 557                 case Opt_acl:
 558                 case Opt_noacl:
 559                         ext2_msg(sb, KERN_INFO,
 560                                 "(no)acl options not supported");
 561                         break;
 562 #endif
 563                 case Opt_xip:
 564                         ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 565                         set_opt(sbi->s_mount_opt, XIP);
 566                         /* Fall through */
 567                 case Opt_dax:
 568 #ifdef CONFIG_FS_DAX
 569                         set_opt(sbi->s_mount_opt, DAX);
 570 #else
 571                         ext2_msg(sb, KERN_INFO, "dax option not supported");
 572 #endif
 573                         break;
 574
 575 #if defined(CONFIG_QUOTA)
 576                 case Opt_quota:
 577                 case Opt_usrquota:
 578                         set_opt(sbi->s_mount_opt, USRQUOTA);
 579                         break;
 580
 581                 case Opt_grpquota:
 582                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 583                         break;
 584 #else
 585                 case Opt_quota:
 586                 case Opt_usrquota:
 587                 case Opt_grpquota:
 588                         ext2_msg(sb, KERN_INFO,
 589                                 "quota operations not supported");
 590                         break;
 591 #endif
 592
 593                 case Opt_reservation:
 594                         set_opt(sbi->s_mount_opt, RESERVATION);
 595                         ext2_msg(sb, KERN_INFO, "reservations ON");
 596                         break;
 597                 case Opt_noreservation:
 598                         clear_opt(sbi->s_mount_opt, RESERVATION);
 599                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 600                         break;
 601                 case Opt_ignore:
 602                         break;
 603                 default:
 604                         return 0;
 605                 }
 606         }
 607         return 1;
 608 }
 609
 610 static int ext2_setup_super (struct super_block * sb,
 611                               struct ext2_super_block * es,
 612                               int read_only)
 613 {
 614         int res = 0;
 615         struct ext2_sb_info *sbi = EXT2_SB(sb);
 616
 617         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 618                 ext2_msg(sb, KERN_ERR,
 619                         "error: revision level too high, "
 620                         "forcing read-only mode");
 621                 res = MS_RDONLY;
 622         }
 623         if (read_only)
 624                 return res;
 625         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 626                 ext2_msg(sb, KERN_WARNING,
 627                         "warning: mounting unchecked fs, "
 628                         "running e2fsck is recommended");
 629         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 630                 ext2_msg(sb, KERN_WARNING,
 631                         "warning: mounting fs with errors, "
 632                         "running e2fsck is recommended");
 633         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 634                  le16_to_cpu(es->s_mnt_count) >=
 635                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 636                 ext2_msg(sb, KERN_WARNING,
 637                         "warning: maximal mount count reached, "
 638                         "running e2fsck is recommended");
 639         else if (le32_to_cpu(es->s_checkinterval) &&
 640                 (le32_to_cpu(es->s_lastcheck) +
 641                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 642                 ext2_msg(sb, KERN_WARNING,
 643                         "warning: checktime reached, "
 644                         "running e2fsck is recommended");
 645         if (!le16_to_cpu(es->s_max_mnt_count))
 646                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 647         le16_add_cpu(&es->s_mnt_count, 1);
 648         if (test_opt (sb, DEBUG))
 649                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 650                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 651                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 652                         sbi->s_frag_size,
 653                         sbi->s_groups_count,
 654                         EXT2_BLOCKS_PER_GROUP(sb),
 655                         EXT2_INODES_PER_GROUP(sb),
 656                         sbi->s_mount_opt);
 657         return res;
 658 }
 659
 660 static int ext2_check_descriptors(struct super_block *sb)
 661 {
 662         int i;
 663         struct ext2_sb_info *sbi = EXT2_SB(sb);
 664
 665         ext2_debug ("Checking group descriptors");
 666
 667         for (i = 0; i < sbi->s_groups_count; i++) {
 668                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 669                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 670                 ext2_fsblk_t last_block;
 671
 672                 if (i == sbi->s_groups_count - 1)
 673                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 674                 else
 675                         last_block = first_block +
 676                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 677
 678                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 679                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 680                 {
 681                         ext2_error (sb, "ext2_check_descriptors",
 682                                     "Block bitmap for group %d"
 683                                     " not in group (block %lu)!",
 684                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 685                         return 0;
 686                 }
 687                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 688                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 689                 {
 690                         ext2_error (sb, "ext2_check_descriptors",
 691                                     "Inode bitmap for group %d"
 692                                     " not in group (block %lu)!",
 693                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 694                         return 0;
 695                 }
 696                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 697                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 698                     last_block)
 699                 {
 700                         ext2_error (sb, "ext2_check_descriptors",
 701                                     "Inode table for group %d"
 702                                     " not in group (block %lu)!",
 703                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 704                         return 0;
 705                 }
 706         }
 707         return 1;
 708 }
 709
 710 /*
 711  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 712  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 713  * We need to be 1 filesystem block less than the 2^32 sector limit.
 714  */
 715 static loff_t ext2_max_size(int bits)
 716 {
 717         loff_t res = EXT2_NDIR_BLOCKS;
 718         int meta_blocks;
 719         loff_t upper_limit;
 720
 721         /* This is calculated to be the largest file size for a
 722          * dense, file such that the total number of
 723          * sectors in the file, including data and all indirect blocks,
 724          * does not exceed 2^32 -1
 725          * __u32 i_blocks representing the total number of
 726          * 512 bytes blocks of the file
 727          */
 728         upper_limit = (1LL << 32) - 1;
 729
 730         /* total blocks in file system block size */
 731         upper_limit >>= (bits - 9);
 732
 733
 734         /* indirect blocks */
 735         meta_blocks = 1;
 736         /* double indirect blocks */
 737         meta_blocks += 1 + (1LL << (bits-2));
 738         /* tripple indirect blocks */
 739         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 740
 741         upper_limit -= meta_blocks;
 742         upper_limit <<= bits;
 743
 744         res += 1LL << (bits-2);
 745         res += 1LL << (2*(bits-2));
 746         res += 1LL << (3*(bits-2));
 747         res <<= bits;
 748         if (res > upper_limit)
 749                 res = upper_limit;
 750
 751         if (res > MAX_LFS_FILESIZE)
 752                 res = MAX_LFS_FILESIZE;
 753
 754         return res;
 755 }
 756
 757 static unsigned long descriptor_loc(struct super_block *sb,
 758                                     unsigned long logic_sb_block,
 759                                     int nr)
 760 {
 761         struct ext2_sb_info *sbi = EXT2_SB(sb);
 762         unsigned long bg, first_meta_bg;
 763         int has_super = 0;
 764
 765         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 766
 767         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 768             nr < first_meta_bg)
 769                 return (logic_sb_block + nr + 1);
 770         bg = sbi->s_desc_per_block * nr;
 771         if (ext2_bg_has_super(sb, bg))
 772                 has_super = 1;
 773
 774         return ext2_group_first_block_no(sb, bg) + has_super;
 775 }
 776
 777 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 778 {
 779         struct buffer_head * bh;
 780         struct ext2_sb_info * sbi;
 781         struct ext2_super_block * es;
 782         struct inode *root;
 783         unsigned long block;
 784         unsigned long sb_block = get_sb_block(&data);
 785         unsigned long logic_sb_block;
 786         unsigned long offset = 0;
 787         unsigned long def_mount_opts;
 788         long ret = -EINVAL;
 789         int blocksize = BLOCK_SIZE;
 790         int db_count;
 791         int i, j;
 792         __le32 features;
 793         int err;
 794
 795         err = -ENOMEM;
 796         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 797         if (!sbi)
 798                 goto failed;
 799
 800         sbi->s_blockgroup_lock =
 801                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 802         if (!sbi->s_blockgroup_lock) {
 803                 kfree(sbi);
 804                 goto failed;
 805         }
 806         sb->s_fs_info = sbi;
 807         sbi->s_sb_block = sb_block;
 808
 809         spin_lock_init(&sbi->s_lock);
 810
 811         /*
 812          * See what the current blocksize for the device is, and
 813          * use that as the blocksize.  Otherwise (or if the blocksize
 814          * is smaller than the default) use the default.
 815          * This is important for devices that have a hardware
 816          * sectorsize that is larger than the default.
 817          */
 818         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 819         if (!blocksize) {
 820                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 821                 goto failed_sbi;
 822         }
 823
 824         /*
 825          * If the superblock doesn't start on a hardware sector boundary,
 826          * calculate the offset.
 827          */
 828         if (blocksize != BLOCK_SIZE) {
 829                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 830                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 831         } else {
 832                 logic_sb_block = sb_block;
 833         }
 834
 835         if (!(bh = sb_bread(sb, logic_sb_block))) {
 836                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 837                 goto failed_sbi;
 838         }
 839         /*
 840          * Note: s_es must be initialized as soon as possible because
 841          *       some ext2 macro-instructions depend on its value
 842          */
 843         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 844         sbi->s_es = es;
 845         sb->s_magic = le16_to_cpu(es->s_magic);
 846
 847         if (sb->s_magic != EXT2_SUPER_MAGIC)
 848                 goto cantfind_ext2;
 849
 850         /* Set defaults before we parse the mount options */
 851         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 852         if (def_mount_opts & EXT2_DEFM_DEBUG)
 853                 set_opt(sbi->s_mount_opt, DEBUG);
 854         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 855                 set_opt(sbi->s_mount_opt, GRPID);
 856         if (def_mount_opts & EXT2_DEFM_UID16)
 857                 set_opt(sbi->s_mount_opt, NO_UID32);
 858 #ifdef CONFIG_EXT2_FS_XATTR
 859         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 860                 set_opt(sbi->s_mount_opt, XATTR_USER);
 861 #endif
 862 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 863         if (def_mount_opts & EXT2_DEFM_ACL)
 864                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 865 #endif
 866
 867         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 868                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 869         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 870                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 871         else
 872                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 873
 874         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 875         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 876
 877         set_opt(sbi->s_mount_opt, RESERVATION);
 878
 879         if (!parse_options((char *) data, sb))
 880                 goto failed_mount;
 881
 882         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 883                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 884                  MS_POSIXACL : 0);
 885
 886         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 887             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 888              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 889              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 890                 ext2_msg(sb, KERN_WARNING,
 891                         "warning: feature flags set on rev 0 fs, "
 892                         "running e2fsck is recommended");
 893         /*
 894          * Check feature flags regardless of the revision level, since we
 895          * previously didn't change the revision level when setting the flags,
 896          * so there is a chance incompat flags are set on a rev 0 filesystem.
 897          */
 898         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 899         if (features) {
 900                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 901                        "unsupported optional features (%x)",
 902                         le32_to_cpu(features));
 903                 goto failed_mount;
 904         }
 905         if (!(sb->s_flags & MS_RDONLY) &&
 906             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 907                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 908                        "unsupported optional features (%x)",
 909                        le32_to_cpu(features));
 910                 goto failed_mount;
 911         }
 912
 913         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 914
 915         if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
 916                 if (blocksize != PAGE_SIZE) {
 917                         ext2_msg(sb, KERN_ERR,
 918                                         "error: unsupported blocksize for dax");
 919                         goto failed_mount;
 920                 }
 921                 if (!sb->s_bdev->bd_disk->fops->direct_access) {
 922                         ext2_msg(sb, KERN_ERR,
 923                                         "error: device does not support dax");
 924                         goto failed_mount;
 925                 }
 926         }
 927
 928         /* If the blocksize doesn't match, re-read the thing.. */
 929         if (sb->s_blocksize != blocksize) {
 930                 brelse(bh);
 931
 932                 if (!sb_set_blocksize(sb, blocksize)) {
 933                         ext2_msg(sb, KERN_ERR,
 934                                 "error: bad blocksize %d", blocksize);
 935                         goto failed_sbi;
 936                 }
 937
 938                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 939                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 940                 bh = sb_bread(sb, logic_sb_block);
 941                 if(!bh) {
 942                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 943                                 "superblock on 2nd try");
 944                         goto failed_sbi;
 945                 }
 946                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 947                 sbi->s_es = es;
 948                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 949                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 950                         goto failed_mount;
 951                 }
 952         }
 953
 954         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 955         sb->s_max_links = EXT2_LINK_MAX;
 956
 957         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 958                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 959                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 960         } else {
 961                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 962                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 963                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 964                     !is_power_of_2(sbi->s_inode_size) ||
 965                     (sbi->s_inode_size > blocksize)) {
 966                         ext2_msg(sb, KERN_ERR,
 967                                 "error: unsupported inode size: %d",
 968                                 sbi->s_inode_size);
 969                         goto failed_mount;
 970                 }
 971         }
 972
 973         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 974                                    le32_to_cpu(es->s_log_frag_size);
 975         if (sbi->s_frag_size == 0)
 976                 goto cantfind_ext2;
 977         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 978
 979         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 980         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 981         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 982
 983         if (EXT2_INODE_SIZE(sb) == 0)
 984                 goto cantfind_ext2;
 985         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 986         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 987                 goto cantfind_ext2;
 988         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 989                                         sbi->s_inodes_per_block;
 990         sbi->s_desc_per_block = sb->s_blocksize /
 991                                         sizeof (struct ext2_group_desc);
 992         sbi->s_sbh = bh;
 993         sbi->s_mount_state = le16_to_cpu(es->s_state);
 994         sbi->s_addr_per_block_bits =
 995                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 996         sbi->s_desc_per_block_bits =
 997                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
 998
 999         if (sb->s_magic != EXT2_SUPER_MAGIC)
1000                 goto cantfind_ext2;
1001
1002         if (sb->s_blocksize != bh->b_size) {
1003                 if (!silent)
1004                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1005                 goto failed_mount;
1006         }
1007
1008         if (sb->s_blocksize != sbi->s_frag_size) {
1009                 ext2_msg(sb, KERN_ERR,
1010                         "error: fragsize %lu != blocksize %lu"
1011                         "(not supported yet)",
1012                         sbi->s_frag_size, sb->s_blocksize);
1013                 goto failed_mount;
1014         }
1015
1016         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1017                 ext2_msg(sb, KERN_ERR,
1018                         "error: #blocks per group too big: %lu",
1019                         sbi->s_blocks_per_group);
1020                 goto failed_mount;
1021         }
1022         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1023                 ext2_msg(sb, KERN_ERR,
1024                         "error: #fragments per group too big: %lu",
1025                         sbi->s_frags_per_group);
1026                 goto failed_mount;
1027         }
1028         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1029                 ext2_msg(sb, KERN_ERR,
1030                         "error: #inodes per group too big: %lu",
1031                         sbi->s_inodes_per_group);
1032                 goto failed_mount;
1033         }
1034
1035         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1036                 goto cantfind_ext2;
1037         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1038                                 le32_to_cpu(es->s_first_data_block) - 1)
1039                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1040         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1041                    EXT2_DESC_PER_BLOCK(sb);
1042         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1043         if (sbi->s_group_desc == NULL) {
1044                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1045                 goto failed_mount;
1046         }
1047         bgl_lock_init(sbi->s_blockgroup_lock);
1048         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1049         if (!sbi->s_debts) {
1050                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1051                 goto failed_mount_group_desc;
1052         }
1053         for (i = 0; i < db_count; i++) {
1054                 block = descriptor_loc(sb, logic_sb_block, i);
1055                 sbi->s_group_desc[i] = sb_bread(sb, block);
1056                 if (!sbi->s_group_desc[i]) {
1057                         for (j = 0; j < i; j++)
1058                                 brelse (sbi->s_group_desc[j]);
1059                         ext2_msg(sb, KERN_ERR,
1060                                 "error: unable to read group descriptors");
1061                         goto failed_mount_group_desc;
1062                 }
1063         }
1064         if (!ext2_check_descriptors (sb)) {
1065                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1066                 goto failed_mount2;
1067         }
1068         sbi->s_gdb_count = db_count;
1069         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1070         spin_lock_init(&sbi->s_next_gen_lock);
1071
1072         /* per fileystem reservation list head & lock */
1073         spin_lock_init(&sbi->s_rsv_window_lock);
1074         sbi->s_rsv_window_root = RB_ROOT;
1075         /*
1076          * Add a single, static dummy reservation to the start of the
1077          * reservation window list --- it gives us a placeholder for
1078          * append-at-start-of-list which makes the allocation logic
1079          * _much_ simpler.
1080          */
1081         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1082         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1083         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1084         sbi->s_rsv_window_head.rsv_goal_size = 0;
1085         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1086
1087         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1088                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1089         if (!err) {
1090                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1091                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1092         }
1093         if (!err) {
1094                 err = percpu_counter_init(&sbi->s_dirs_counter,
1095                                 ext2_count_dirs(sb), GFP_KERNEL);
1096         }
1097         if (err) {
1098                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1099                 goto failed_mount3;
1100         }
1101         /*
1102          * set up enough so that it can read an inode
1103          */
1104         sb->s_op = &ext2_sops;
1105         sb->s_export_op = &ext2_export_ops;
1106         sb->s_xattr = ext2_xattr_handlers;
1107
1108 #ifdef CONFIG_QUOTA
1109         sb->dq_op = &dquot_operations;
1110         sb->s_qcop = &dquot_quotactl_ops;
1111         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1112 #endif
1113
1114         root = ext2_iget(sb, EXT2_ROOT_INO);
1115         if (IS_ERR(root)) {
1116                 ret = PTR_ERR(root);
1117                 goto failed_mount3;
1118         }
1119         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1120                 iput(root);
1121                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1122                 goto failed_mount3;
1123         }
1124
1125         sb->s_root = d_make_root(root);
1126         if (!sb->s_root) {
1127                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1128                 ret = -ENOMEM;
1129                 goto failed_mount3;
1130         }
1131         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1132                 ext2_msg(sb, KERN_WARNING,
1133                         "warning: mounting ext3 filesystem as ext2");
1134         if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1135                 sb->s_flags |= MS_RDONLY;
1136         ext2_write_super(sb);
1137         return 0;
1138
1139 cantfind_ext2:
1140         if (!silent)
1141                 ext2_msg(sb, KERN_ERR,
1142                         "error: can't find an ext2 filesystem on dev %s.",
1143                         sb->s_id);
1144         goto failed_mount;
1145 failed_mount3:
1146         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1147         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1148         percpu_counter_destroy(&sbi->s_dirs_counter);
1149 failed_mount2:
1150         for (i = 0; i < db_count; i++)
1151                 brelse(sbi->s_group_desc[i]);
1152 failed_mount_group_desc:
1153         kfree(sbi->s_group_desc);
1154         kfree(sbi->s_debts);
1155 failed_mount:
1156         brelse(bh);
1157 failed_sbi:
1158         sb->s_fs_info = NULL;
1159         kfree(sbi->s_blockgroup_lock);
1160         kfree(sbi);
1161 failed:
1162         return ret;
1163 }
1164
1165 static void ext2_clear_super_error(struct super_block *sb)
1166 {
1167         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1168
1169         if (buffer_write_io_error(sbh)) {
1170                 /*
1171                  * Oh, dear.  A previous attempt to write the
1172                  * superblock failed.  This could happen because the
1173                  * USB device was yanked out.  Or it could happen to
1174                  * be a transient write error and maybe the block will
1175                  * be remapped.  Nothing we can do but to retry the
1176                  * write and hope for the best.
1177                  */
1178                 ext2_msg(sb, KERN_ERR,
1179                        "previous I/O error to superblock detected\n");
1180                 clear_buffer_write_io_error(sbh);
1181                 set_buffer_uptodate(sbh);
1182         }
1183 }
1184
1185 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1186                             int wait)
1187 {
1188         ext2_clear_super_error(sb);
1189         spin_lock(&EXT2_SB(sb)->s_lock);
1190         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1191         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1192         es->s_wtime = cpu_to_le32(get_seconds());
1193         /* unlock before we do IO */
1194         spin_unlock(&EXT2_SB(sb)->s_lock);
1195         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1196         if (wait)
1197                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1198 }
1199
1200 /*
1201  * In the second extended file system, it is not necessary to
1202  * write the super block since we use a mapping of the
1203  * disk super block in a buffer.
1204  *
1205  * However, this function is still used to set the fs valid
1206  * flags to 0.  We need to set this flag to 0 since the fs
1207  * may have been checked while mounted and e2fsck may have
1208  * set s_state to EXT2_VALID_FS after some corrections.
1209  */
1210 static int ext2_sync_fs(struct super_block *sb, int wait)
1211 {
1212         struct ext2_sb_info *sbi = EXT2_SB(sb);
1213         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1214
1215         /*
1216          * Write quota structures to quota file, sync_blockdev() will write
1217          * them to disk later
1218          */
1219         dquot_writeback_dquots(sb, -1);
1220
1221         spin_lock(&sbi->s_lock);
1222         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1223                 ext2_debug("setting valid to 0\n");
1224                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1225         }
1226         spin_unlock(&sbi->s_lock);
1227         ext2_sync_super(sb, es, wait);
1228         return 0;
1229 }
1230
1231 static int ext2_freeze(struct super_block *sb)
1232 {
1233         struct ext2_sb_info *sbi = EXT2_SB(sb);
1234
1235         /*
1236          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1237          * because we have unattached inodes and thus filesystem is not fully
1238          * consistent.
1239          */
1240         if (atomic_long_read(&sb->s_remove_count)) {
1241                 ext2_sync_fs(sb, 1);
1242                 return 0;
1243         }
1244         /* Set EXT2_FS_VALID flag */
1245         spin_lock(&sbi->s_lock);
1246         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1247         spin_unlock(&sbi->s_lock);
1248         ext2_sync_super(sb, sbi->s_es, 1);
1249
1250         return 0;
1251 }
1252
1253 static int ext2_unfreeze(struct super_block *sb)
1254 {
1255         /* Just write sb to clear EXT2_VALID_FS flag */
1256         ext2_write_super(sb);
1257
1258         return 0;
1259 }
1260
1261 void ext2_write_super(struct super_block *sb)
1262 {
1263         if (!(sb->s_flags & MS_RDONLY))
1264                 ext2_sync_fs(sb, 1);
1265 }
1266
1267 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1268 {
1269         struct ext2_sb_info * sbi = EXT2_SB(sb);
1270         struct ext2_super_block * es;
1271         struct ext2_mount_options old_opts;
1272         unsigned long old_sb_flags;
1273         int err;
1274
1275         sync_filesystem(sb);
1276         spin_lock(&sbi->s_lock);
1277
1278         /* Store the old options */
1279         old_sb_flags = sb->s_flags;
1280         old_opts.s_mount_opt = sbi->s_mount_opt;
1281         old_opts.s_resuid = sbi->s_resuid;
1282         old_opts.s_resgid = sbi->s_resgid;
1283
1284         /*
1285          * Allow the "check" option to be passed as a remount option.
1286          */
1287         if (!parse_options(data, sb)) {
1288                 err = -EINVAL;
1289                 goto restore_opts;
1290         }
1291
1292         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1293                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1294
1295         es = sbi->s_es;
1296         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1297                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1298                          "dax flag with busy inodes while remounting");
1299                 sbi->s_mount_opt ^= EXT2_MOUNT_DAX;
1300         }
1301         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1302                 spin_unlock(&sbi->s_lock);
1303                 return 0;
1304         }
1305         if (*flags & MS_RDONLY) {
1306                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1307                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
1308                         spin_unlock(&sbi->s_lock);
1309                         return 0;
1310                 }
1311
1312                 /*
1313                  * OK, we are remounting a valid rw partition rdonly, so set
1314                  * the rdonly flag and then mark the partition as valid again.
1315                  */
1316                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1317                 es->s_mtime = cpu_to_le32(get_seconds());
1318                 spin_unlock(&sbi->s_lock);
1319
1320                 err = dquot_suspend(sb, -1);
1321                 if (err < 0) {
1322                         spin_lock(&sbi->s_lock);
1323                         goto restore_opts;
1324                 }
1325
1326                 ext2_sync_super(sb, es, 1);
1327         } else {
1328                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1329                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1330                 if (ret) {
1331                         ext2_msg(sb, KERN_WARNING,
1332                                 "warning: couldn't remount RDWR because of "
1333                                 "unsupported optional features (%x).",
1334                                 le32_to_cpu(ret));
1335                         err = -EROFS;
1336                         goto restore_opts;
1337                 }
1338                 /*
1339                  * Mounting a RDONLY partition read-write, so reread and
1340                  * store the current valid flag.  (It may have been changed
1341                  * by e2fsck since we originally mounted the partition.)
1342                  */
1343                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1344                 if (!ext2_setup_super (sb, es, 0))
1345                         sb->s_flags &= ~MS_RDONLY;
1346                 spin_unlock(&sbi->s_lock);
1347
1348                 ext2_write_super(sb);
1349
1350                 dquot_resume(sb, -1);
1351         }
1352
1353         return 0;
1354 restore_opts:
1355         sbi->s_mount_opt = old_opts.s_mount_opt;
1356         sbi->s_resuid = old_opts.s_resuid;
1357         sbi->s_resgid = old_opts.s_resgid;
1358         sb->s_flags = old_sb_flags;
1359         spin_unlock(&sbi->s_lock);
1360         return err;
1361 }
1362
1363 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1364 {
1365         struct super_block *sb = dentry->d_sb;
1366         struct ext2_sb_info *sbi = EXT2_SB(sb);
1367         struct ext2_super_block *es = sbi->s_es;
1368         u64 fsid;
1369
1370         spin_lock(&sbi->s_lock);
1371
1372         if (test_opt (sb, MINIX_DF))
1373                 sbi->s_overhead_last = 0;
1374         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1375                 unsigned long i, overhead = 0;
1376                 smp_rmb();
1377
1378                 /*
1379                  * Compute the overhead (FS structures). This is constant
1380                  * for a given filesystem unless the number of block groups
1381                  * changes so we cache the previous value until it does.
1382                  */
1383
1384                 /*
1385                  * All of the blocks before first_data_block are
1386                  * overhead
1387                  */
1388                 overhead = le32_to_cpu(es->s_first_data_block);
1389
1390                 /*
1391                  * Add the overhead attributed to the superblock and
1392                  * block group descriptors.  If the sparse superblocks
1393                  * feature is turned on, then not all groups have this.
1394                  */
1395                 for (i = 0; i < sbi->s_groups_count; i++)
1396                         overhead += ext2_bg_has_super(sb, i) +
1397                                 ext2_bg_num_gdb(sb, i);
1398
1399                 /*
1400                  * Every block group has an inode bitmap, a block
1401                  * bitmap, and an inode table.
1402                  */
1403                 overhead += (sbi->s_groups_count *
1404                              (2 + sbi->s_itb_per_group));
1405                 sbi->s_overhead_last = overhead;
1406                 smp_wmb();
1407                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1408         }
1409
1410         buf->f_type = EXT2_SUPER_MAGIC;
1411         buf->f_bsize = sb->s_blocksize;
1412         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1413         buf->f_bfree = ext2_count_free_blocks(sb);
1414         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1415         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1416         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1417                 buf->f_bavail = 0;
1418         buf->f_files = le32_to_cpu(es->s_inodes_count);
1419         buf->f_ffree = ext2_count_free_inodes(sb);
1420         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1421         buf->f_namelen = EXT2_NAME_LEN;
1422         fsid = le64_to_cpup((void *)es->s_uuid) ^
1423                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1424         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1425         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1426         spin_unlock(&sbi->s_lock);
1427         return 0;
1428 }
1429
1430 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1431         int flags, const char *dev_name, void *data)
1432 {
1433         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1434 }
1435
1436 #ifdef CONFIG_QUOTA
1437
1438 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1439  * acquiring the locks... As quota files are never truncated and quota code
1440  * itself serializes the operations (and no one else should touch the files)
1441  * we don't have to be afraid of races */
1442 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1443                                size_t len, loff_t off)
1444 {
1445         struct inode *inode = sb_dqopt(sb)->files[type];
1446         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1447         int err = 0;
1448         int offset = off & (sb->s_blocksize - 1);
1449         int tocopy;
1450         size_t toread;
1451         struct buffer_head tmp_bh;
1452         struct buffer_head *bh;
1453         loff_t i_size = i_size_read(inode);
1454
1455         if (off > i_size)
1456                 return 0;
1457         if (off+len > i_size)
1458                 len = i_size-off;
1459         toread = len;
1460         while (toread > 0) {
1461                 tocopy = sb->s_blocksize - offset < toread ?
1462                                 sb->s_blocksize - offset : toread;
1463
1464                 tmp_bh.b_state = 0;
1465                 tmp_bh.b_size = sb->s_blocksize;
1466                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1467                 if (err < 0)
1468                         return err;
1469                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1470                         memset(data, 0, tocopy);
1471                 else {
1472                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1473                         if (!bh)
1474                                 return -EIO;
1475                         memcpy(data, bh->b_data+offset, tocopy);
1476                         brelse(bh);
1477                 }
1478                 offset = 0;
1479                 toread -= tocopy;
1480                 data += tocopy;
1481                 blk++;
1482         }
1483         return len;
1484 }
1485
1486 /* Write to quotafile */
1487 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1488                                 const char *data, size_t len, loff_t off)
1489 {
1490         struct inode *inode = sb_dqopt(sb)->files[type];
1491         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1492         int err = 0;
1493         int offset = off & (sb->s_blocksize - 1);
1494         int tocopy;
1495         size_t towrite = len;
1496         struct buffer_head tmp_bh;
1497         struct buffer_head *bh;
1498
1499         while (towrite > 0) {
1500                 tocopy = sb->s_blocksize - offset < towrite ?
1501                                 sb->s_blocksize - offset : towrite;
1502
1503                 tmp_bh.b_state = 0;
1504                 tmp_bh.b_size = sb->s_blocksize;
1505                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1506                 if (err < 0)
1507                         goto out;
1508                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1509                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1510                 else
1511                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1512                 if (unlikely(!bh)) {
1513                         err = -EIO;
1514                         goto out;
1515                 }
1516                 lock_buffer(bh);
1517                 memcpy(bh->b_data+offset, data, tocopy);
1518                 flush_dcache_page(bh->b_page);
1519                 set_buffer_uptodate(bh);
1520                 mark_buffer_dirty(bh);
1521                 unlock_buffer(bh);
1522                 brelse(bh);
1523                 offset = 0;
1524                 towrite -= tocopy;
1525                 data += tocopy;
1526                 blk++;
1527         }
1528 out:
1529         if (len == towrite)
1530                 return err;
1531         if (inode->i_size < off+len-towrite)
1532                 i_size_write(inode, off+len-towrite);
1533         inode->i_version++;
1534         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1535         mark_inode_dirty(inode);
1536         return len - towrite;
1537 }
1538
1539 #endif
1540
1541 static struct file_system_type ext2_fs_type = {
1542         .owner          = THIS_MODULE,
1543         .name           = "ext2",
1544         .mount          = ext2_mount,
1545         .kill_sb        = kill_block_super,
1546         .fs_flags       = FS_REQUIRES_DEV,
1547 };
1548 MODULE_ALIAS_FS("ext2");
1549
1550 static int __init init_ext2_fs(void)
1551 {
1552         int err = init_ext2_xattr();
1553         if (err)
1554                 return err;
1555         err = init_inodecache();
1556         if (err)
1557                 goto out1;
1558         err = register_filesystem(&ext2_fs_type);
1559         if (err)
1560                 goto out;
1561         return 0;
1562 out:
1563         destroy_inodecache();
1564 out1:
1565         exit_ext2_xattr();
1566         return err;
1567 }
1568
1569 static void __exit exit_ext2_fs(void)
1570 {
1571         unregister_filesystem(&ext2_fs_type);
1572         destroy_inodecache();
1573         exit_ext2_xattr();
1574 }
1575
1576 MODULE_AUTHOR("Remy Card and others");
1577 MODULE_DESCRIPTION("Second Extended Filesystem");
1578 MODULE_LICENSE("GPL");
1579 module_init(init_ext2_fs)
1580 module_exit(exit_ext2_fs)