fs/ext2/super.c

   1 /*
   2  *  linux/fs/ext2/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card ([email protected])
   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 ([email protected]), 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 #include "xip.h"
  39
  40 static void ext2_sync_super(struct super_block *sb,
  41                             struct ext2_super_block *es, int wait);
  42 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  43 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  44 static int ext2_sync_fs(struct super_block *sb, int wait);
  45 static int ext2_freeze(struct super_block *sb);
  46 static int ext2_unfreeze(struct super_block *sb);
  47
  48 void ext2_error(struct super_block *sb, const char *function,
  49                 const char *fmt, ...)
  50 {
  51         struct va_format vaf;
  52         va_list args;
  53         struct ext2_sb_info *sbi = EXT2_SB(sb);
  54         struct ext2_super_block *es = sbi->s_es;
  55
  56         if (!(sb->s_flags & MS_RDONLY)) {
  57                 spin_lock(&sbi->s_lock);
  58                 sbi->s_mount_state |= EXT2_ERROR_FS;
  59                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  60                 spin_unlock(&sbi->s_lock);
  61                 ext2_sync_super(sb, es, 1);
  62         }
  63
  64         va_start(args, fmt);
  65
  66         vaf.fmt = fmt;
  67         vaf.va = &args;
  68
  69         printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  70                sb->s_id, function, &vaf);
  71
  72         va_end(args);
  73
  74         if (test_opt(sb, ERRORS_PANIC))
  75                 panic("EXT2-fs: panic from previous error\n");
  76         if (test_opt(sb, ERRORS_RO)) {
  77                 ext2_msg(sb, KERN_CRIT,
  78                              "error: remounting filesystem read-only");
  79                 sb->s_flags |= MS_RDONLY;
  80         }
  81 }
  82
  83 void ext2_msg(struct super_block *sb, const char *prefix,
  84                 const char *fmt, ...)
  85 {
  86         struct va_format vaf;
  87         va_list args;
  88
  89         va_start(args, fmt);
  90
  91         vaf.fmt = fmt;
  92         vaf.va = &args;
  93
  94         printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  95
  96         va_end(args);
  97 }
  98
  99 /*
 100  * This must be called with sbi->s_lock held.
 101  */
 102 void ext2_update_dynamic_rev(struct super_block *sb)
 103 {
 104         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 105
 106         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 107                 return;
 108
 109         ext2_msg(sb, KERN_WARNING,
 110                      "warning: updating to rev %d because of "
 111                      "new feature flag, running e2fsck is recommended",
 112                      EXT2_DYNAMIC_REV);
 113
 114         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 115         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 116         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 117         /* leave es->s_feature_*compat flags alone */
 118         /* es->s_uuid will be set by e2fsck if empty */
 119
 120         /*
 121          * The rest of the superblock fields should be zero, and if not it
 122          * means they are likely already in use, so leave them alone.  We
 123          * can leave it up to e2fsck to clean up any inconsistencies there.
 124          */
 125 }
 126
 127 static void ext2_put_super (struct super_block * sb)
 128 {
 129         int db_count;
 130         int i;
 131         struct ext2_sb_info *sbi = EXT2_SB(sb);
 132
 133         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 134
 135         ext2_xattr_put_super(sb);
 136         if (!(sb->s_flags & MS_RDONLY)) {
 137                 struct ext2_super_block *es = sbi->s_es;
 138
 139                 spin_lock(&sbi->s_lock);
 140                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 141                 spin_unlock(&sbi->s_lock);
 142                 ext2_sync_super(sb, es, 1);
 143         }
 144         db_count = sbi->s_gdb_count;
 145         for (i = 0; i < db_count; i++)
 146                 if (sbi->s_group_desc[i])
 147                         brelse (sbi->s_group_desc[i]);
 148         kfree(sbi->s_group_desc);
 149         kfree(sbi->s_debts);
 150         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 151         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 152         percpu_counter_destroy(&sbi->s_dirs_counter);
 153         brelse (sbi->s_sbh);
 154         sb->s_fs_info = NULL;
 155         kfree(sbi->s_blockgroup_lock);
 156         kfree(sbi);
 157 }
 158
 159 static struct kmem_cache * ext2_inode_cachep;
 160
 161 static struct inode *ext2_alloc_inode(struct super_block *sb)
 162 {
 163         struct ext2_inode_info *ei;
 164         ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 165         if (!ei)
 166                 return NULL;
 167         ei->i_block_alloc_info = NULL;
 168         ei->vfs_inode.i_version = 1;
 169 #ifdef CONFIG_QUOTA
 170         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 171 #endif
 172
 173         return &ei->vfs_inode;
 174 }
 175
 176 static void ext2_i_callback(struct rcu_head *head)
 177 {
 178         struct inode *inode = container_of(head, struct inode, i_rcu);
 179         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 180 }
 181
 182 static void ext2_destroy_inode(struct inode *inode)
 183 {
 184         call_rcu(&inode->i_rcu, ext2_i_callback);
 185 }
 186
 187 static void init_once(void *foo)
 188 {
 189         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 190
 191         rwlock_init(&ei->i_meta_lock);
 192 #ifdef CONFIG_EXT2_FS_XATTR
 193         init_rwsem(&ei->xattr_sem);
 194 #endif
 195         mutex_init(&ei->truncate_mutex);
 196         inode_init_once(&ei->vfs_inode);
 197 }
 198
 199 static int __init init_inodecache(void)
 200 {
 201         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 202                                              sizeof(struct ext2_inode_info),
 203                                              0, (SLAB_RECLAIM_ACCOUNT|
 204                                                 SLAB_MEM_SPREAD),
 205                                              init_once);
 206         if (ext2_inode_cachep == NULL)
 207                 return -ENOMEM;
 208         return 0;
 209 }
 210
 211 static void destroy_inodecache(void)
 212 {
 213         /*
 214          * Make sure all delayed rcu free inodes are flushed before we
 215          * destroy cache.
 216          */
 217         rcu_barrier();
 218         kmem_cache_destroy(ext2_inode_cachep);
 219 }
 220
 221 static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 222 {
 223         struct super_block *sb = root->d_sb;
 224         struct ext2_sb_info *sbi = EXT2_SB(sb);
 225         struct ext2_super_block *es = sbi->s_es;
 226         unsigned long def_mount_opts;
 227
 228         spin_lock(&sbi->s_lock);
 229         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 230
 231         if (sbi->s_sb_block != 1)
 232                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 233         if (test_opt(sb, MINIX_DF))
 234                 seq_puts(seq, ",minixdf");
 235         if (test_opt(sb, GRPID))
 236                 seq_puts(seq, ",grpid");
 237         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 238                 seq_puts(seq, ",nogrpid");
 239         if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 240             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 241                 seq_printf(seq, ",resuid=%u",
 242                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
 243         }
 244         if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 245             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 246                 seq_printf(seq, ",resgid=%u",
 247                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
 248         }
 249         if (test_opt(sb, ERRORS_RO)) {
 250                 int def_errors = le16_to_cpu(es->s_errors);
 251
 252                 if (def_errors == EXT2_ERRORS_PANIC ||
 253                     def_errors == EXT2_ERRORS_CONTINUE) {
 254                         seq_puts(seq, ",errors=remount-ro");
 255                 }
 256         }
 257         if (test_opt(sb, ERRORS_CONT))
 258                 seq_puts(seq, ",errors=continue");
 259         if (test_opt(sb, ERRORS_PANIC))
 260                 seq_puts(seq, ",errors=panic");
 261         if (test_opt(sb, NO_UID32))
 262                 seq_puts(seq, ",nouid32");
 263         if (test_opt(sb, DEBUG))
 264                 seq_puts(seq, ",debug");
 265         if (test_opt(sb, OLDALLOC))
 266                 seq_puts(seq, ",oldalloc");
 267
 268 #ifdef CONFIG_EXT2_FS_XATTR
 269         if (test_opt(sb, XATTR_USER))
 270                 seq_puts(seq, ",user_xattr");
 271         if (!test_opt(sb, XATTR_USER) &&
 272             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 273                 seq_puts(seq, ",nouser_xattr");
 274         }
 275 #endif
 276
 277 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 278         if (test_opt(sb, POSIX_ACL))
 279                 seq_puts(seq, ",acl");
 280         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 281                 seq_puts(seq, ",noacl");
 282 #endif
 283
 284         if (test_opt(sb, NOBH))
 285                 seq_puts(seq, ",nobh");
 286
 287 #if defined(CONFIG_QUOTA)
 288         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 289                 seq_puts(seq, ",usrquota");
 290
 291         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 292                 seq_puts(seq, ",grpquota");
 293 #endif
 294
 295 #if defined(CONFIG_EXT2_FS_XIP)
 296         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 297                 seq_puts(seq, ",xip");
 298 #endif
 299
 300         if (!test_opt(sb, RESERVATION))
 301                 seq_puts(seq, ",noreservation");
 302
 303         spin_unlock(&sbi->s_lock);
 304         return 0;
 305 }
 306
 307 #ifdef CONFIG_QUOTA
 308 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 309 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 310 static struct dquot **ext2_get_dquots(struct inode *inode)
 311 {
 312         return EXT2_I(inode)->i_dquot;
 313 }
 314 #endif
 315
 316 static const struct super_operations ext2_sops = {
 317         .alloc_inode    = ext2_alloc_inode,
 318         .destroy_inode  = ext2_destroy_inode,
 319         .write_inode    = ext2_write_inode,
 320         .evict_inode    = ext2_evict_inode,
 321         .put_super      = ext2_put_super,
 322         .sync_fs        = ext2_sync_fs,
 323         .freeze_fs      = ext2_freeze,
 324         .unfreeze_fs    = ext2_unfreeze,
 325         .statfs         = ext2_statfs,
 326         .remount_fs     = ext2_remount,
 327         .show_options   = ext2_show_options,
 328 #ifdef CONFIG_QUOTA
 329         .quota_read     = ext2_quota_read,
 330         .quota_write    = ext2_quota_write,
 331         .get_dquots     = ext2_get_dquots,
 332 #endif
 333 };
 334
 335 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 336                 u64 ino, u32 generation)
 337 {
 338         struct inode *inode;
 339
 340         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 341                 return ERR_PTR(-ESTALE);
 342         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 343                 return ERR_PTR(-ESTALE);
 344
 345         /*
 346          * ext2_iget isn't quite right if the inode is currently unallocated!
 347          * However ext2_iget currently does appropriate checks to handle stale
 348          * inodes so everything is OK.
 349          */
 350         inode = ext2_iget(sb, ino);
 351         if (IS_ERR(inode))
 352                 return ERR_CAST(inode);
 353         if (generation && inode->i_generation != generation) {
 354                 /* we didn't find the right inode.. */
 355                 iput(inode);
 356                 return ERR_PTR(-ESTALE);
 357         }
 358         return inode;
 359 }
 360
 361 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 362                 int fh_len, int fh_type)
 363 {
 364         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 365                                     ext2_nfs_get_inode);
 366 }
 367
 368 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 369                 int fh_len, int fh_type)
 370 {
 371         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 372                                     ext2_nfs_get_inode);
 373 }
 374
 375 static const struct export_operations ext2_export_ops = {
 376         .fh_to_dentry = ext2_fh_to_dentry,
 377         .fh_to_parent = ext2_fh_to_parent,
 378         .get_parent = ext2_get_parent,
 379 };
 380
 381 static unsigned long get_sb_block(void **data)
 382 {
 383         unsigned long   sb_block;
 384         char            *options = (char *) *data;
 385
 386         if (!options || strncmp(options, "sb=", 3) != 0)
 387                 return 1;       /* Default location */
 388         options += 3;
 389         sb_block = simple_strtoul(options, &options, 0);
 390         if (*options && *options != ',') {
 391                 printk("EXT2-fs: Invalid sb specification: %s\n",
 392                        (char *) *data);
 393                 return 1;
 394         }
 395         if (*options == ',')
 396                 options++;
 397         *data = (void *) options;
 398         return sb_block;
 399 }
 400
 401 enum {
 402         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 403         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 404         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 405         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 406         Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 407         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 408 };
 409
 410 static const match_table_t tokens = {
 411         {Opt_bsd_df, "bsddf"},
 412         {Opt_minix_df, "minixdf"},
 413         {Opt_grpid, "grpid"},
 414         {Opt_grpid, "bsdgroups"},
 415         {Opt_nogrpid, "nogrpid"},
 416         {Opt_nogrpid, "sysvgroups"},
 417         {Opt_resgid, "resgid=%u"},
 418         {Opt_resuid, "resuid=%u"},
 419         {Opt_sb, "sb=%u"},
 420         {Opt_err_cont, "errors=continue"},
 421         {Opt_err_panic, "errors=panic"},
 422         {Opt_err_ro, "errors=remount-ro"},
 423         {Opt_nouid32, "nouid32"},
 424         {Opt_nocheck, "check=none"},
 425         {Opt_nocheck, "nocheck"},
 426         {Opt_debug, "debug"},
 427         {Opt_oldalloc, "oldalloc"},
 428         {Opt_orlov, "orlov"},
 429         {Opt_nobh, "nobh"},
 430         {Opt_user_xattr, "user_xattr"},
 431         {Opt_nouser_xattr, "nouser_xattr"},
 432         {Opt_acl, "acl"},
 433         {Opt_noacl, "noacl"},
 434         {Opt_xip, "xip"},
 435         {Opt_grpquota, "grpquota"},
 436         {Opt_ignore, "noquota"},
 437         {Opt_quota, "quota"},
 438         {Opt_usrquota, "usrquota"},
 439         {Opt_reservation, "reservation"},
 440         {Opt_noreservation, "noreservation"},
 441         {Opt_err, NULL}
 442 };
 443
 444 static int parse_options(char *options, struct super_block *sb)
 445 {
 446         char *p;
 447         struct ext2_sb_info *sbi = EXT2_SB(sb);
 448         substring_t args[MAX_OPT_ARGS];
 449         int option;
 450         kuid_t uid;
 451         kgid_t gid;
 452
 453         if (!options)
 454                 return 1;
 455
 456         while ((p = strsep (&options, ",")) != NULL) {
 457                 int token;
 458                 if (!*p)
 459                         continue;
 460
 461                 token = match_token(p, tokens, args);
 462                 switch (token) {
 463                 case Opt_bsd_df:
 464                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 465                         break;
 466                 case Opt_minix_df:
 467                         set_opt (sbi->s_mount_opt, MINIX_DF);
 468                         break;
 469                 case Opt_grpid:
 470                         set_opt (sbi->s_mount_opt, GRPID);
 471                         break;
 472                 case Opt_nogrpid:
 473                         clear_opt (sbi->s_mount_opt, GRPID);
 474                         break;
 475                 case Opt_resuid:
 476                         if (match_int(&args[0], &option))
 477                                 return 0;
 478                         uid = make_kuid(current_user_ns(), option);
 479                         if (!uid_valid(uid)) {
 480                                 ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 481                                 return 0;
 482
 483                         }
 484                         sbi->s_resuid = uid;
 485                         break;
 486                 case Opt_resgid:
 487                         if (match_int(&args[0], &option))
 488                                 return 0;
 489                         gid = make_kgid(current_user_ns(), option);
 490                         if (!gid_valid(gid)) {
 491                                 ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 492                                 return 0;
 493                         }
 494                         sbi->s_resgid = gid;
 495                         break;
 496                 case Opt_sb:
 497                         /* handled by get_sb_block() instead of here */
 498                         /* *sb_block = match_int(&args[0]); */
 499                         break;
 500                 case Opt_err_panic:
 501                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 502                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 503                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 504                         break;
 505                 case Opt_err_ro:
 506                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 507                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 508                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 509                         break;
 510                 case Opt_err_cont:
 511                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 512                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 513                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 514                         break;
 515                 case Opt_nouid32:
 516                         set_opt (sbi->s_mount_opt, NO_UID32);
 517                         break;
 518                 case Opt_nocheck:
 519                         clear_opt (sbi->s_mount_opt, CHECK);
 520                         break;
 521                 case Opt_debug:
 522                         set_opt (sbi->s_mount_opt, DEBUG);
 523                         break;
 524                 case Opt_oldalloc:
 525                         set_opt (sbi->s_mount_opt, OLDALLOC);
 526                         break;
 527                 case Opt_orlov:
 528                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 529                         break;
 530                 case Opt_nobh:
 531                         set_opt (sbi->s_mount_opt, NOBH);
 532                         break;
 533 #ifdef CONFIG_EXT2_FS_XATTR
 534                 case Opt_user_xattr:
 535                         set_opt (sbi->s_mount_opt, XATTR_USER);
 536                         break;
 537                 case Opt_nouser_xattr:
 538                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 539                         break;
 540 #else
 541                 case Opt_user_xattr:
 542                 case Opt_nouser_xattr:
 543                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 544                                 "not supported");
 545                         break;
 546 #endif
 547 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 548                 case Opt_acl:
 549                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 550                         break;
 551                 case Opt_noacl:
 552                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 553                         break;
 554 #else
 555                 case Opt_acl:
 556                 case Opt_noacl:
 557                         ext2_msg(sb, KERN_INFO,
 558                                 "(no)acl options not supported");
 559                         break;
 560 #endif
 561                 case Opt_xip:
 562 #ifdef CONFIG_EXT2_FS_XIP
 563                         set_opt (sbi->s_mount_opt, XIP);
 564 #else
 565                         ext2_msg(sb, KERN_INFO, "xip option not supported");
 566 #endif
 567                         break;
 568
 569 #if defined(CONFIG_QUOTA)
 570                 case Opt_quota:
 571                 case Opt_usrquota:
 572                         set_opt(sbi->s_mount_opt, USRQUOTA);
 573                         break;
 574
 575                 case Opt_grpquota:
 576                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 577                         break;
 578 #else
 579                 case Opt_quota:
 580                 case Opt_usrquota:
 581                 case Opt_grpquota:
 582                         ext2_msg(sb, KERN_INFO,
 583                                 "quota operations not supported");
 584                         break;
 585 #endif
 586
 587                 case Opt_reservation:
 588                         set_opt(sbi->s_mount_opt, RESERVATION);
 589                         ext2_msg(sb, KERN_INFO, "reservations ON");
 590                         break;
 591                 case Opt_noreservation:
 592                         clear_opt(sbi->s_mount_opt, RESERVATION);
 593                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 594                         break;
 595                 case Opt_ignore:
 596                         break;
 597                 default:
 598                         return 0;
 599                 }
 600         }
 601         return 1;
 602 }
 603
 604 static int ext2_setup_super (struct super_block * sb,
 605                               struct ext2_super_block * es,
 606                               int read_only)
 607 {
 608         int res = 0;
 609         struct ext2_sb_info *sbi = EXT2_SB(sb);
 610
 611         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 612                 ext2_msg(sb, KERN_ERR,
 613                         "error: revision level too high, "
 614                         "forcing read-only mode");
 615                 res = MS_RDONLY;
 616         }
 617         if (read_only)
 618                 return res;
 619         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 620                 ext2_msg(sb, KERN_WARNING,
 621                         "warning: mounting unchecked fs, "
 622                         "running e2fsck is recommended");
 623         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 624                 ext2_msg(sb, KERN_WARNING,
 625                         "warning: mounting fs with errors, "
 626                         "running e2fsck is recommended");
 627         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 628                  le16_to_cpu(es->s_mnt_count) >=
 629                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 630                 ext2_msg(sb, KERN_WARNING,
 631                         "warning: maximal mount count reached, "
 632                         "running e2fsck is recommended");
 633         else if (le32_to_cpu(es->s_checkinterval) &&
 634                 (le32_to_cpu(es->s_lastcheck) +
 635                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 636                 ext2_msg(sb, KERN_WARNING,
 637                         "warning: checktime reached, "
 638                         "running e2fsck is recommended");
 639         if (!le16_to_cpu(es->s_max_mnt_count))
 640                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 641         le16_add_cpu(&es->s_mnt_count, 1);
 642         if (test_opt (sb, DEBUG))
 643                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 644                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 645                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 646                         sbi->s_frag_size,
 647                         sbi->s_groups_count,
 648                         EXT2_BLOCKS_PER_GROUP(sb),
 649                         EXT2_INODES_PER_GROUP(sb),
 650                         sbi->s_mount_opt);
 651         return res;
 652 }
 653
 654 static int ext2_check_descriptors(struct super_block *sb)
 655 {
 656         int i;
 657         struct ext2_sb_info *sbi = EXT2_SB(sb);
 658
 659         ext2_debug ("Checking group descriptors");
 660
 661         for (i = 0; i < sbi->s_groups_count; i++) {
 662                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 663                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 664                 ext2_fsblk_t last_block;
 665
 666                 if (i == sbi->s_groups_count - 1)
 667                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 668                 else
 669                         last_block = first_block +
 670                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 671
 672                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 673                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 674                 {
 675                         ext2_error (sb, "ext2_check_descriptors",
 676                                     "Block bitmap for group %d"
 677                                     " not in group (block %lu)!",
 678                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 679                         return 0;
 680                 }
 681                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 682                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 683                 {
 684                         ext2_error (sb, "ext2_check_descriptors",
 685                                     "Inode bitmap for group %d"
 686                                     " not in group (block %lu)!",
 687                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 688                         return 0;
 689                 }
 690                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 691                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 692                     last_block)
 693                 {
 694                         ext2_error (sb, "ext2_check_descriptors",
 695                                     "Inode table for group %d"
 696                                     " not in group (block %lu)!",
 697                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 698                         return 0;
 699                 }
 700         }
 701         return 1;
 702 }
 703
 704 /*
 705  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 706  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 707  * We need to be 1 filesystem block less than the 2^32 sector limit.
 708  */
 709 static loff_t ext2_max_size(int bits)
 710 {
 711         loff_t res = EXT2_NDIR_BLOCKS;
 712         int meta_blocks;
 713         loff_t upper_limit;
 714
 715         /* This is calculated to be the largest file size for a
 716          * dense, file such that the total number of
 717          * sectors in the file, including data and all indirect blocks,
 718          * does not exceed 2^32 -1
 719          * __u32 i_blocks representing the total number of
 720          * 512 bytes blocks of the file
 721          */
 722         upper_limit = (1LL << 32) - 1;
 723
 724         /* total blocks in file system block size */
 725         upper_limit >>= (bits - 9);
 726
 727
 728         /* indirect blocks */
 729         meta_blocks = 1;
 730         /* double indirect blocks */
 731         meta_blocks += 1 + (1LL << (bits-2));
 732         /* tripple indirect blocks */
 733         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 734
 735         upper_limit -= meta_blocks;
 736         upper_limit <<= bits;
 737
 738         res += 1LL << (bits-2);
 739         res += 1LL << (2*(bits-2));
 740         res += 1LL << (3*(bits-2));
 741         res <<= bits;
 742         if (res > upper_limit)
 743                 res = upper_limit;
 744
 745         if (res > MAX_LFS_FILESIZE)
 746                 res = MAX_LFS_FILESIZE;
 747
 748         return res;
 749 }
 750
 751 static unsigned long descriptor_loc(struct super_block *sb,
 752                                     unsigned long logic_sb_block,
 753                                     int nr)
 754 {
 755         struct ext2_sb_info *sbi = EXT2_SB(sb);
 756         unsigned long bg, first_meta_bg;
 757         int has_super = 0;
 758
 759         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 760
 761         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 762             nr < first_meta_bg)
 763                 return (logic_sb_block + nr + 1);
 764         bg = sbi->s_desc_per_block * nr;
 765         if (ext2_bg_has_super(sb, bg))
 766                 has_super = 1;
 767
 768         return ext2_group_first_block_no(sb, bg) + has_super;
 769 }
 770
 771 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 772 {
 773         struct buffer_head * bh;
 774         struct ext2_sb_info * sbi;
 775         struct ext2_super_block * es;
 776         struct inode *root;
 777         unsigned long block;
 778         unsigned long sb_block = get_sb_block(&data);
 779         unsigned long logic_sb_block;
 780         unsigned long offset = 0;
 781         unsigned long def_mount_opts;
 782         long ret = -EINVAL;
 783         int blocksize = BLOCK_SIZE;
 784         int db_count;
 785         int i, j;
 786         __le32 features;
 787         int err;
 788
 789         err = -ENOMEM;
 790         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 791         if (!sbi)
 792                 goto failed;
 793
 794         sbi->s_blockgroup_lock =
 795                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 796         if (!sbi->s_blockgroup_lock) {
 797                 kfree(sbi);
 798                 goto failed;
 799         }
 800         sb->s_fs_info = sbi;
 801         sbi->s_sb_block = sb_block;
 802
 803         spin_lock_init(&sbi->s_lock);
 804
 805         /*
 806          * See what the current blocksize for the device is, and
 807          * use that as the blocksize.  Otherwise (or if the blocksize
 808          * is smaller than the default) use the default.
 809          * This is important for devices that have a hardware
 810          * sectorsize that is larger than the default.
 811          */
 812         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 813         if (!blocksize) {
 814                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 815                 goto failed_sbi;
 816         }
 817
 818         /*
 819          * If the superblock doesn't start on a hardware sector boundary,
 820          * calculate the offset.
 821          */
 822         if (blocksize != BLOCK_SIZE) {
 823                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 824                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 825         } else {
 826                 logic_sb_block = sb_block;
 827         }
 828
 829         if (!(bh = sb_bread(sb, logic_sb_block))) {
 830                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 831                 goto failed_sbi;
 832         }
 833         /*
 834          * Note: s_es must be initialized as soon as possible because
 835          *       some ext2 macro-instructions depend on its value
 836          */
 837         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 838         sbi->s_es = es;
 839         sb->s_magic = le16_to_cpu(es->s_magic);
 840
 841         if (sb->s_magic != EXT2_SUPER_MAGIC)
 842                 goto cantfind_ext2;
 843
 844         /* Set defaults before we parse the mount options */
 845         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 846         if (def_mount_opts & EXT2_DEFM_DEBUG)
 847                 set_opt(sbi->s_mount_opt, DEBUG);
 848         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 849                 set_opt(sbi->s_mount_opt, GRPID);
 850         if (def_mount_opts & EXT2_DEFM_UID16)
 851                 set_opt(sbi->s_mount_opt, NO_UID32);
 852 #ifdef CONFIG_EXT2_FS_XATTR
 853         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 854                 set_opt(sbi->s_mount_opt, XATTR_USER);
 855 #endif
 856 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 857         if (def_mount_opts & EXT2_DEFM_ACL)
 858                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 859 #endif
 860
 861         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 862                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 863         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 864                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 865         else
 866                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 867
 868         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 869         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 870
 871         set_opt(sbi->s_mount_opt, RESERVATION);
 872
 873         if (!parse_options((char *) data, sb))
 874                 goto failed_mount;
 875
 876         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 877                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 878                  MS_POSIXACL : 0);
 879
 880         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 881                                     EXT2_MOUNT_XIP if not */
 882
 883         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 884             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 885              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 886              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 887                 ext2_msg(sb, KERN_WARNING,
 888                         "warning: feature flags set on rev 0 fs, "
 889                         "running e2fsck is recommended");
 890         /*
 891          * Check feature flags regardless of the revision level, since we
 892          * previously didn't change the revision level when setting the flags,
 893          * so there is a chance incompat flags are set on a rev 0 filesystem.
 894          */
 895         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 896         if (features) {
 897                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 898                        "unsupported optional features (%x)",
 899                         le32_to_cpu(features));
 900                 goto failed_mount;
 901         }
 902         if (!(sb->s_flags & MS_RDONLY) &&
 903             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 904                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 905                        "unsupported optional features (%x)",
 906                        le32_to_cpu(features));
 907                 goto failed_mount;
 908         }
 909
 910         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 911
 912         if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
 913                 if (!silent)
 914                         ext2_msg(sb, KERN_ERR,
 915                                 "error: unsupported blocksize for xip");
 916                 goto failed_mount;
 917         }
 918
 919         /* If the blocksize doesn't match, re-read the thing.. */
 920         if (sb->s_blocksize != blocksize) {
 921                 brelse(bh);
 922
 923                 if (!sb_set_blocksize(sb, blocksize)) {
 924                         ext2_msg(sb, KERN_ERR,
 925                                 "error: bad blocksize %d", blocksize);
 926                         goto failed_sbi;
 927                 }
 928
 929                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 930                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 931                 bh = sb_bread(sb, logic_sb_block);
 932                 if(!bh) {
 933                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 934                                 "superblock on 2nd try");
 935                         goto failed_sbi;
 936                 }
 937                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 938                 sbi->s_es = es;
 939                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 940                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 941                         goto failed_mount;
 942                 }
 943         }
 944
 945         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 946         sb->s_max_links = EXT2_LINK_MAX;
 947
 948         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 949                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 950                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 951         } else {
 952                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 953                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 954                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 955                     !is_power_of_2(sbi->s_inode_size) ||
 956                     (sbi->s_inode_size > blocksize)) {
 957                         ext2_msg(sb, KERN_ERR,
 958                                 "error: unsupported inode size: %d",
 959                                 sbi->s_inode_size);
 960                         goto failed_mount;
 961                 }
 962         }
 963
 964         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 965                                    le32_to_cpu(es->s_log_frag_size);
 966         if (sbi->s_frag_size == 0)
 967                 goto cantfind_ext2;
 968         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 969
 970         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 971         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 972         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 973
 974         if (EXT2_INODE_SIZE(sb) == 0)
 975                 goto cantfind_ext2;
 976         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 977         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 978                 goto cantfind_ext2;
 979         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 980                                         sbi->s_inodes_per_block;
 981         sbi->s_desc_per_block = sb->s_blocksize /
 982                                         sizeof (struct ext2_group_desc);
 983         sbi->s_sbh = bh;
 984         sbi->s_mount_state = le16_to_cpu(es->s_state);
 985         sbi->s_addr_per_block_bits =
 986                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 987         sbi->s_desc_per_block_bits =
 988                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
 989
 990         if (sb->s_magic != EXT2_SUPER_MAGIC)
 991                 goto cantfind_ext2;
 992
 993         if (sb->s_blocksize != bh->b_size) {
 994                 if (!silent)
 995                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
 996                 goto failed_mount;
 997         }
 998
 999         if (sb->s_blocksize != sbi->s_frag_size) {
1000                 ext2_msg(sb, KERN_ERR,
1001                         "error: fragsize %lu != blocksize %lu"
1002                         "(not supported yet)",
1003                         sbi->s_frag_size, sb->s_blocksize);
1004                 goto failed_mount;
1005         }
1006
1007         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1008                 ext2_msg(sb, KERN_ERR,
1009                         "error: #blocks per group too big: %lu",
1010                         sbi->s_blocks_per_group);
1011                 goto failed_mount;
1012         }
1013         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1014                 ext2_msg(sb, KERN_ERR,
1015                         "error: #fragments per group too big: %lu",
1016                         sbi->s_frags_per_group);
1017                 goto failed_mount;
1018         }
1019         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1020                 ext2_msg(sb, KERN_ERR,
1021                         "error: #inodes per group too big: %lu",
1022                         sbi->s_inodes_per_group);
1023                 goto failed_mount;
1024         }
1025
1026         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1027                 goto cantfind_ext2;
1028         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1029                                 le32_to_cpu(es->s_first_data_block) - 1)
1030                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1031         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1032                    EXT2_DESC_PER_BLOCK(sb);
1033         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1034         if (sbi->s_group_desc == NULL) {
1035                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1036                 goto failed_mount;
1037         }
1038         bgl_lock_init(sbi->s_blockgroup_lock);
1039         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1040         if (!sbi->s_debts) {
1041                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1042                 goto failed_mount_group_desc;
1043         }
1044         for (i = 0; i < db_count; i++) {
1045                 block = descriptor_loc(sb, logic_sb_block, i);
1046                 sbi->s_group_desc[i] = sb_bread(sb, block);
1047                 if (!sbi->s_group_desc[i]) {
1048                         for (j = 0; j < i; j++)
1049                                 brelse (sbi->s_group_desc[j]);
1050                         ext2_msg(sb, KERN_ERR,
1051                                 "error: unable to read group descriptors");
1052                         goto failed_mount_group_desc;
1053                 }
1054         }
1055         if (!ext2_check_descriptors (sb)) {
1056                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1057                 goto failed_mount2;
1058         }
1059         sbi->s_gdb_count = db_count;
1060         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1061         spin_lock_init(&sbi->s_next_gen_lock);
1062
1063         /* per fileystem reservation list head & lock */
1064         spin_lock_init(&sbi->s_rsv_window_lock);
1065         sbi->s_rsv_window_root = RB_ROOT;
1066         /*
1067          * Add a single, static dummy reservation to the start of the
1068          * reservation window list --- it gives us a placeholder for
1069          * append-at-start-of-list which makes the allocation logic
1070          * _much_ simpler.
1071          */
1072         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1073         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1074         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1075         sbi->s_rsv_window_head.rsv_goal_size = 0;
1076         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1077
1078         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1079                                 ext2_count_free_blocks(sb), GFP_KERNEL);
1080         if (!err) {
1081                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1082                                 ext2_count_free_inodes(sb), GFP_KERNEL);
1083         }
1084         if (!err) {
1085                 err = percpu_counter_init(&sbi->s_dirs_counter,
1086                                 ext2_count_dirs(sb), GFP_KERNEL);
1087         }
1088         if (err) {
1089                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1090                 goto failed_mount3;
1091         }
1092         /*
1093          * set up enough so that it can read an inode
1094          */
1095         sb->s_op = &ext2_sops;
1096         sb->s_export_op = &ext2_export_ops;
1097         sb->s_xattr = ext2_xattr_handlers;
1098
1099 #ifdef CONFIG_QUOTA
1100         sb->dq_op = &dquot_operations;
1101         sb->s_qcop = &dquot_quotactl_ops;
1102         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1103 #endif
1104
1105         root = ext2_iget(sb, EXT2_ROOT_INO);
1106         if (IS_ERR(root)) {
1107                 ret = PTR_ERR(root);
1108                 goto failed_mount3;
1109         }
1110         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1111                 iput(root);
1112                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1113                 goto failed_mount3;
1114         }
1115
1116         sb->s_root = d_make_root(root);
1117         if (!sb->s_root) {
1118                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1119                 ret = -ENOMEM;
1120                 goto failed_mount3;
1121         }
1122         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1123                 ext2_msg(sb, KERN_WARNING,
1124                         "warning: mounting ext3 filesystem as ext2");
1125         if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1126                 sb->s_flags |= MS_RDONLY;
1127         ext2_write_super(sb);
1128         return 0;
1129
1130 cantfind_ext2:
1131         if (!silent)
1132                 ext2_msg(sb, KERN_ERR,
1133                         "error: can't find an ext2 filesystem on dev %s.",
1134                         sb->s_id);
1135         goto failed_mount;
1136 failed_mount3:
1137         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1138         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1139         percpu_counter_destroy(&sbi->s_dirs_counter);
1140 failed_mount2:
1141         for (i = 0; i < db_count; i++)
1142                 brelse(sbi->s_group_desc[i]);
1143 failed_mount_group_desc:
1144         kfree(sbi->s_group_desc);
1145         kfree(sbi->s_debts);
1146 failed_mount:
1147         brelse(bh);
1148 failed_sbi:
1149         sb->s_fs_info = NULL;
1150         kfree(sbi->s_blockgroup_lock);
1151         kfree(sbi);
1152 failed:
1153         return ret;
1154 }
1155
1156 static void ext2_clear_super_error(struct super_block *sb)
1157 {
1158         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1159
1160         if (buffer_write_io_error(sbh)) {
1161                 /*
1162                  * Oh, dear.  A previous attempt to write the
1163                  * superblock failed.  This could happen because the
1164                  * USB device was yanked out.  Or it could happen to
1165                  * be a transient write error and maybe the block will
1166                  * be remapped.  Nothing we can do but to retry the
1167                  * write and hope for the best.
1168                  */
1169                 ext2_msg(sb, KERN_ERR,
1170                        "previous I/O error to superblock detected\n");
1171                 clear_buffer_write_io_error(sbh);
1172                 set_buffer_uptodate(sbh);
1173         }
1174 }
1175
1176 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1177                             int wait)
1178 {
1179         ext2_clear_super_error(sb);
1180         spin_lock(&EXT2_SB(sb)->s_lock);
1181         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1182         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1183         es->s_wtime = cpu_to_le32(get_seconds());
1184         /* unlock before we do IO */
1185         spin_unlock(&EXT2_SB(sb)->s_lock);
1186         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1187         if (wait)
1188                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1189 }
1190
1191 /*
1192  * In the second extended file system, it is not necessary to
1193  * write the super block since we use a mapping of the
1194  * disk super block in a buffer.
1195  *
1196  * However, this function is still used to set the fs valid
1197  * flags to 0.  We need to set this flag to 0 since the fs
1198  * may have been checked while mounted and e2fsck may have
1199  * set s_state to EXT2_VALID_FS after some corrections.
1200  */
1201 static int ext2_sync_fs(struct super_block *sb, int wait)
1202 {
1203         struct ext2_sb_info *sbi = EXT2_SB(sb);
1204         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1205
1206         /*
1207          * Write quota structures to quota file, sync_blockdev() will write
1208          * them to disk later
1209          */
1210         dquot_writeback_dquots(sb, -1);
1211
1212         spin_lock(&sbi->s_lock);
1213         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1214                 ext2_debug("setting valid to 0\n");
1215                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1216         }
1217         spin_unlock(&sbi->s_lock);
1218         ext2_sync_super(sb, es, wait);
1219         return 0;
1220 }
1221
1222 static int ext2_freeze(struct super_block *sb)
1223 {
1224         struct ext2_sb_info *sbi = EXT2_SB(sb);
1225
1226         /*
1227          * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1228          * because we have unattached inodes and thus filesystem is not fully
1229          * consistent.
1230          */
1231         if (atomic_long_read(&sb->s_remove_count)) {
1232                 ext2_sync_fs(sb, 1);
1233                 return 0;
1234         }
1235         /* Set EXT2_FS_VALID flag */
1236         spin_lock(&sbi->s_lock);
1237         sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1238         spin_unlock(&sbi->s_lock);
1239         ext2_sync_super(sb, sbi->s_es, 1);
1240
1241         return 0;
1242 }
1243
1244 static int ext2_unfreeze(struct super_block *sb)
1245 {
1246         /* Just write sb to clear EXT2_VALID_FS flag */
1247         ext2_write_super(sb);
1248
1249         return 0;
1250 }
1251
1252 void ext2_write_super(struct super_block *sb)
1253 {
1254         if (!(sb->s_flags & MS_RDONLY))
1255                 ext2_sync_fs(sb, 1);
1256 }
1257
1258 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1259 {
1260         struct ext2_sb_info * sbi = EXT2_SB(sb);
1261         struct ext2_super_block * es;
1262         unsigned long old_mount_opt = sbi->s_mount_opt;
1263         struct ext2_mount_options old_opts;
1264         unsigned long old_sb_flags;
1265         int err;
1266
1267         sync_filesystem(sb);
1268         spin_lock(&sbi->s_lock);
1269
1270         /* Store the old options */
1271         old_sb_flags = sb->s_flags;
1272         old_opts.s_mount_opt = sbi->s_mount_opt;
1273         old_opts.s_resuid = sbi->s_resuid;
1274         old_opts.s_resgid = sbi->s_resgid;
1275
1276         /*
1277          * Allow the "check" option to be passed as a remount option.
1278          */
1279         if (!parse_options(data, sb)) {
1280                 err = -EINVAL;
1281                 goto restore_opts;
1282         }
1283
1284         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1285                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1286
1287         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1288                                     EXT2_MOUNT_XIP if not */
1289
1290         if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1291                 ext2_msg(sb, KERN_WARNING,
1292                         "warning: unsupported blocksize for xip");
1293                 err = -EINVAL;
1294                 goto restore_opts;
1295         }
1296
1297         es = sbi->s_es;
1298         if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
1299                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1300                          "xip flag with busy inodes while remounting");
1301                 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1302                 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1303         }
1304         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1305                 spin_unlock(&sbi->s_lock);
1306                 return 0;
1307         }
1308         if (*flags & MS_RDONLY) {
1309                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1310                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
1311                         spin_unlock(&sbi->s_lock);
1312                         return 0;
1313                 }
1314
1315                 /*
1316                  * OK, we are remounting a valid rw partition rdonly, so set
1317                  * the rdonly flag and then mark the partition as valid again.
1318                  */
1319                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1320                 es->s_mtime = cpu_to_le32(get_seconds());
1321                 spin_unlock(&sbi->s_lock);
1322
1323                 err = dquot_suspend(sb, -1);
1324                 if (err < 0) {
1325                         spin_lock(&sbi->s_lock);
1326                         goto restore_opts;
1327                 }
1328
1329                 ext2_sync_super(sb, es, 1);
1330         } else {
1331                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1332                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1333                 if (ret) {
1334                         ext2_msg(sb, KERN_WARNING,
1335                                 "warning: couldn't remount RDWR because of "
1336                                 "unsupported optional features (%x).",
1337                                 le32_to_cpu(ret));
1338                         err = -EROFS;
1339                         goto restore_opts;
1340                 }
1341                 /*
1342                  * Mounting a RDONLY partition read-write, so reread and
1343                  * store the current valid flag.  (It may have been changed
1344                  * by e2fsck since we originally mounted the partition.)
1345                  */
1346                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1347                 if (!ext2_setup_super (sb, es, 0))
1348                         sb->s_flags &= ~MS_RDONLY;
1349                 spin_unlock(&sbi->s_lock);
1350
1351                 ext2_write_super(sb);
1352
1353                 dquot_resume(sb, -1);
1354         }
1355
1356         return 0;
1357 restore_opts:
1358         sbi->s_mount_opt = old_opts.s_mount_opt;
1359         sbi->s_resuid = old_opts.s_resuid;
1360         sbi->s_resgid = old_opts.s_resgid;
1361         sb->s_flags = old_sb_flags;
1362         spin_unlock(&sbi->s_lock);
1363         return err;
1364 }
1365
1366 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1367 {
1368         struct super_block *sb = dentry->d_sb;
1369         struct ext2_sb_info *sbi = EXT2_SB(sb);
1370         struct ext2_super_block *es = sbi->s_es;
1371         u64 fsid;
1372
1373         spin_lock(&sbi->s_lock);
1374
1375         if (test_opt (sb, MINIX_DF))
1376                 sbi->s_overhead_last = 0;
1377         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1378                 unsigned long i, overhead = 0;
1379                 smp_rmb();
1380
1381                 /*
1382                  * Compute the overhead (FS structures). This is constant
1383                  * for a given filesystem unless the number of block groups
1384                  * changes so we cache the previous value until it does.
1385                  */
1386
1387                 /*
1388                  * All of the blocks before first_data_block are
1389                  * overhead
1390                  */
1391                 overhead = le32_to_cpu(es->s_first_data_block);
1392
1393                 /*
1394                  * Add the overhead attributed to the superblock and
1395                  * block group descriptors.  If the sparse superblocks
1396                  * feature is turned on, then not all groups have this.
1397                  */
1398                 for (i = 0; i < sbi->s_groups_count; i++)
1399                         overhead += ext2_bg_has_super(sb, i) +
1400                                 ext2_bg_num_gdb(sb, i);
1401
1402                 /*
1403                  * Every block group has an inode bitmap, a block
1404                  * bitmap, and an inode table.
1405                  */
1406                 overhead += (sbi->s_groups_count *
1407                              (2 + sbi->s_itb_per_group));
1408                 sbi->s_overhead_last = overhead;
1409                 smp_wmb();
1410                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1411         }
1412
1413         buf->f_type = EXT2_SUPER_MAGIC;
1414         buf->f_bsize = sb->s_blocksize;
1415         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1416         buf->f_bfree = ext2_count_free_blocks(sb);
1417         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1418         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1419         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1420                 buf->f_bavail = 0;
1421         buf->f_files = le32_to_cpu(es->s_inodes_count);
1422         buf->f_ffree = ext2_count_free_inodes(sb);
1423         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1424         buf->f_namelen = EXT2_NAME_LEN;
1425         fsid = le64_to_cpup((void *)es->s_uuid) ^
1426                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1427         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1428         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1429         spin_unlock(&sbi->s_lock);
1430         return 0;
1431 }
1432
1433 static struct dentry *ext2_mount(struct file_system_type *fs_type,
1434         int flags, const char *dev_name, void *data)
1435 {
1436         return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1437 }
1438
1439 #ifdef CONFIG_QUOTA
1440
1441 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1442  * acquiring the locks... As quota files are never truncated and quota code
1443  * itself serializes the operations (and no one else should touch the files)
1444  * we don't have to be afraid of races */
1445 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1446                                size_t len, loff_t off)
1447 {
1448         struct inode *inode = sb_dqopt(sb)->files[type];
1449         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1450         int err = 0;
1451         int offset = off & (sb->s_blocksize - 1);
1452         int tocopy;
1453         size_t toread;
1454         struct buffer_head tmp_bh;
1455         struct buffer_head *bh;
1456         loff_t i_size = i_size_read(inode);
1457
1458         if (off > i_size)
1459                 return 0;
1460         if (off+len > i_size)
1461                 len = i_size-off;
1462         toread = len;
1463         while (toread > 0) {
1464                 tocopy = sb->s_blocksize - offset < toread ?
1465                                 sb->s_blocksize - offset : toread;
1466
1467                 tmp_bh.b_state = 0;
1468                 tmp_bh.b_size = sb->s_blocksize;
1469                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1470                 if (err < 0)
1471                         return err;
1472                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1473                         memset(data, 0, tocopy);
1474                 else {
1475                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1476                         if (!bh)
1477                                 return -EIO;
1478                         memcpy(data, bh->b_data+offset, tocopy);
1479                         brelse(bh);
1480                 }
1481                 offset = 0;
1482                 toread -= tocopy;
1483                 data += tocopy;
1484                 blk++;
1485         }
1486         return len;
1487 }
1488
1489 /* Write to quotafile */
1490 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1491                                 const char *data, size_t len, loff_t off)
1492 {
1493         struct inode *inode = sb_dqopt(sb)->files[type];
1494         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1495         int err = 0;
1496         int offset = off & (sb->s_blocksize - 1);
1497         int tocopy;
1498         size_t towrite = len;
1499         struct buffer_head tmp_bh;
1500         struct buffer_head *bh;
1501
1502         while (towrite > 0) {
1503                 tocopy = sb->s_blocksize - offset < towrite ?
1504                                 sb->s_blocksize - offset : towrite;
1505
1506                 tmp_bh.b_state = 0;
1507                 tmp_bh.b_size = sb->s_blocksize;
1508                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1509                 if (err < 0)
1510                         goto out;
1511                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1512                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1513                 else
1514                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1515                 if (unlikely(!bh)) {
1516                         err = -EIO;
1517                         goto out;
1518                 }
1519                 lock_buffer(bh);
1520                 memcpy(bh->b_data+offset, data, tocopy);
1521                 flush_dcache_page(bh->b_page);
1522                 set_buffer_uptodate(bh);
1523                 mark_buffer_dirty(bh);
1524                 unlock_buffer(bh);
1525                 brelse(bh);
1526                 offset = 0;
1527                 towrite -= tocopy;
1528                 data += tocopy;
1529                 blk++;
1530         }
1531 out:
1532         if (len == towrite)
1533                 return err;
1534         if (inode->i_size < off+len-towrite)
1535                 i_size_write(inode, off+len-towrite);
1536         inode->i_version++;
1537         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1538         mark_inode_dirty(inode);
1539         return len - towrite;
1540 }
1541
1542 #endif
1543
1544 static struct file_system_type ext2_fs_type = {
1545         .owner          = THIS_MODULE,
1546         .name           = "ext2",
1547         .mount          = ext2_mount,
1548         .kill_sb        = kill_block_super,
1549         .fs_flags       = FS_REQUIRES_DEV,
1550 };
1551 MODULE_ALIAS_FS("ext2");
1552
1553 static int __init init_ext2_fs(void)
1554 {
1555         int err = init_ext2_xattr();
1556         if (err)
1557                 return err;
1558         err = init_inodecache();
1559         if (err)
1560                 goto out1;
1561         err = register_filesystem(&ext2_fs_type);
1562         if (err)
1563                 goto out;
1564         return 0;
1565 out:
1566         destroy_inodecache();
1567 out1:
1568         exit_ext2_xattr();
1569         return err;
1570 }
1571
1572 static void __exit exit_ext2_fs(void)
1573 {
1574         unregister_filesystem(&ext2_fs_type);
1575         destroy_inodecache();
1576         exit_ext2_xattr();
1577 }
1578
1579 MODULE_AUTHOR("Remy Card and others");
1580 MODULE_DESCRIPTION("Second Extended Filesystem");
1581 MODULE_LICENSE("GPL");
1582 module_init(init_ext2_fs)
1583 module_exit(exit_ext2_fs)