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 #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
  46 void ext2_error (struct super_block * sb, const char * function,
  47                  const char * fmt, ...)
  48 {
  49         va_list args;
  50         struct ext2_sb_info *sbi = EXT2_SB(sb);
  51         struct ext2_super_block *es = sbi->s_es;
  52
  53         if (!(sb->s_flags & MS_RDONLY)) {
  54                 spin_lock(&sbi->s_lock);
  55                 sbi->s_mount_state |= EXT2_ERROR_FS;
  56                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  57                 spin_unlock(&sbi->s_lock);
  58                 ext2_sync_super(sb, es, 1);
  59         }
  60
  61         va_start(args, fmt);
  62         printk(KERN_CRIT "EXT2-fs (%s): error: %s: ", sb->s_id, function);
  63         vprintk(fmt, args);
  64         printk("\n");
  65         va_end(args);
  66
  67         if (test_opt(sb, ERRORS_PANIC))
  68                 panic("EXT2-fs: panic from previous error\n");
  69         if (test_opt(sb, ERRORS_RO)) {
  70                 ext2_msg(sb, KERN_CRIT,
  71                              "error: remounting filesystem read-only");
  72                 sb->s_flags |= MS_RDONLY;
  73         }
  74 }
  75
  76 void ext2_msg(struct super_block *sb, const char *prefix,
  77                 const char *fmt, ...)
  78 {
  79         va_list args;
  80
  81         va_start(args, fmt);
  82         printk("%sEXT2-fs (%s): ", prefix, sb->s_id);
  83         vprintk(fmt, args);
  84         printk("\n");
  85         va_end(args);
  86 }
  87
  88 /*
  89  * This must be called with sbi->s_lock held.
  90  */
  91 void ext2_update_dynamic_rev(struct super_block *sb)
  92 {
  93         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
  94
  95         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
  96                 return;
  97
  98         ext2_msg(sb, KERN_WARNING,
  99                      "warning: updating to rev %d because of "
 100                      "new feature flag, running e2fsck is recommended",
 101                      EXT2_DYNAMIC_REV);
 102
 103         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 104         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 105         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 106         /* leave es->s_feature_*compat flags alone */
 107         /* es->s_uuid will be set by e2fsck if empty */
 108
 109         /*
 110          * The rest of the superblock fields should be zero, and if not it
 111          * means they are likely already in use, so leave them alone.  We
 112          * can leave it up to e2fsck to clean up any inconsistencies there.
 113          */
 114 }
 115
 116 static void ext2_put_super (struct super_block * sb)
 117 {
 118         int db_count;
 119         int i;
 120         struct ext2_sb_info *sbi = EXT2_SB(sb);
 121
 122         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 123
 124         if (sb->s_dirt)
 125                 ext2_write_super(sb);
 126
 127         ext2_xattr_put_super(sb);
 128         if (!(sb->s_flags & MS_RDONLY)) {
 129                 struct ext2_super_block *es = sbi->s_es;
 130
 131                 spin_lock(&sbi->s_lock);
 132                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 133                 spin_unlock(&sbi->s_lock);
 134                 ext2_sync_super(sb, es, 1);
 135         }
 136         db_count = sbi->s_gdb_count;
 137         for (i = 0; i < db_count; i++)
 138                 if (sbi->s_group_desc[i])
 139                         brelse (sbi->s_group_desc[i]);
 140         kfree(sbi->s_group_desc);
 141         kfree(sbi->s_debts);
 142         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 143         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 144         percpu_counter_destroy(&sbi->s_dirs_counter);
 145         brelse (sbi->s_sbh);
 146         sb->s_fs_info = NULL;
 147         kfree(sbi->s_blockgroup_lock);
 148         kfree(sbi);
 149 }
 150
 151 static struct kmem_cache * ext2_inode_cachep;
 152
 153 static struct inode *ext2_alloc_inode(struct super_block *sb)
 154 {
 155         struct ext2_inode_info *ei;
 156         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 157         if (!ei)
 158                 return NULL;
 159         ei->i_block_alloc_info = NULL;
 160         ei->vfs_inode.i_version = 1;
 161         return &ei->vfs_inode;
 162 }
 163
 164 static void ext2_destroy_inode(struct inode *inode)
 165 {
 166         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 167 }
 168
 169 static void init_once(void *foo)
 170 {
 171         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 172
 173         rwlock_init(&ei->i_meta_lock);
 174 #ifdef CONFIG_EXT2_FS_XATTR
 175         init_rwsem(&ei->xattr_sem);
 176 #endif
 177         mutex_init(&ei->truncate_mutex);
 178         inode_init_once(&ei->vfs_inode);
 179 }
 180
 181 static int init_inodecache(void)
 182 {
 183         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 184                                              sizeof(struct ext2_inode_info),
 185                                              0, (SLAB_RECLAIM_ACCOUNT|
 186                                                 SLAB_MEM_SPREAD),
 187                                              init_once);
 188         if (ext2_inode_cachep == NULL)
 189                 return -ENOMEM;
 190         return 0;
 191 }
 192
 193 static void destroy_inodecache(void)
 194 {
 195         kmem_cache_destroy(ext2_inode_cachep);
 196 }
 197
 198 static void ext2_clear_inode(struct inode *inode)
 199 {
 200         struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
 201
 202         dquot_drop(inode);
 203         ext2_discard_reservation(inode);
 204         EXT2_I(inode)->i_block_alloc_info = NULL;
 205         if (unlikely(rsv))
 206                 kfree(rsv);
 207 }
 208
 209 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
 210 {
 211         struct super_block *sb = vfs->mnt_sb;
 212         struct ext2_sb_info *sbi = EXT2_SB(sb);
 213         struct ext2_super_block *es = sbi->s_es;
 214         unsigned long def_mount_opts;
 215
 216         spin_lock(&sbi->s_lock);
 217         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 218
 219         if (sbi->s_sb_block != 1)
 220                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 221         if (test_opt(sb, MINIX_DF))
 222                 seq_puts(seq, ",minixdf");
 223         if (test_opt(sb, GRPID))
 224                 seq_puts(seq, ",grpid");
 225         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 226                 seq_puts(seq, ",nogrpid");
 227         if (sbi->s_resuid != EXT2_DEF_RESUID ||
 228             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 229                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 230         }
 231         if (sbi->s_resgid != EXT2_DEF_RESGID ||
 232             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 233                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 234         }
 235         if (test_opt(sb, ERRORS_RO)) {
 236                 int def_errors = le16_to_cpu(es->s_errors);
 237
 238                 if (def_errors == EXT2_ERRORS_PANIC ||
 239                     def_errors == EXT2_ERRORS_CONTINUE) {
 240                         seq_puts(seq, ",errors=remount-ro");
 241                 }
 242         }
 243         if (test_opt(sb, ERRORS_CONT))
 244                 seq_puts(seq, ",errors=continue");
 245         if (test_opt(sb, ERRORS_PANIC))
 246                 seq_puts(seq, ",errors=panic");
 247         if (test_opt(sb, NO_UID32))
 248                 seq_puts(seq, ",nouid32");
 249         if (test_opt(sb, DEBUG))
 250                 seq_puts(seq, ",debug");
 251         if (test_opt(sb, OLDALLOC))
 252                 seq_puts(seq, ",oldalloc");
 253
 254 #ifdef CONFIG_EXT2_FS_XATTR
 255         if (test_opt(sb, XATTR_USER))
 256                 seq_puts(seq, ",user_xattr");
 257         if (!test_opt(sb, XATTR_USER) &&
 258             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 259                 seq_puts(seq, ",nouser_xattr");
 260         }
 261 #endif
 262
 263 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 264         if (test_opt(sb, POSIX_ACL))
 265                 seq_puts(seq, ",acl");
 266         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 267                 seq_puts(seq, ",noacl");
 268 #endif
 269
 270         if (test_opt(sb, NOBH))
 271                 seq_puts(seq, ",nobh");
 272
 273 #if defined(CONFIG_QUOTA)
 274         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 275                 seq_puts(seq, ",usrquota");
 276
 277         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 278                 seq_puts(seq, ",grpquota");
 279 #endif
 280
 281 #if defined(CONFIG_EXT2_FS_XIP)
 282         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 283                 seq_puts(seq, ",xip");
 284 #endif
 285
 286         if (!test_opt(sb, RESERVATION))
 287                 seq_puts(seq, ",noreservation");
 288
 289         spin_unlock(&sbi->s_lock);
 290         return 0;
 291 }
 292
 293 #ifdef CONFIG_QUOTA
 294 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 295 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 296 #endif
 297
 298 static const struct super_operations ext2_sops = {
 299         .alloc_inode    = ext2_alloc_inode,
 300         .destroy_inode  = ext2_destroy_inode,
 301         .write_inode    = ext2_write_inode,
 302         .delete_inode   = ext2_delete_inode,
 303         .put_super      = ext2_put_super,
 304         .write_super    = ext2_write_super,
 305         .sync_fs        = ext2_sync_fs,
 306         .statfs         = ext2_statfs,
 307         .remount_fs     = ext2_remount,
 308         .clear_inode    = ext2_clear_inode,
 309         .show_options   = ext2_show_options,
 310 #ifdef CONFIG_QUOTA
 311         .quota_read     = ext2_quota_read,
 312         .quota_write    = ext2_quota_write,
 313 #endif
 314 };
 315
 316 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 317                 u64 ino, u32 generation)
 318 {
 319         struct inode *inode;
 320
 321         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 322                 return ERR_PTR(-ESTALE);
 323         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 324                 return ERR_PTR(-ESTALE);
 325
 326         /* iget isn't really right if the inode is currently unallocated!!
 327          * ext2_read_inode currently does appropriate checks, but
 328          * it might be "neater" to call ext2_get_inode first and check
 329          * if the inode is valid.....
 330          */
 331         inode = ext2_iget(sb, ino);
 332         if (IS_ERR(inode))
 333                 return ERR_CAST(inode);
 334         if (generation && inode->i_generation != generation) {
 335                 /* we didn't find the right inode.. */
 336                 iput(inode);
 337                 return ERR_PTR(-ESTALE);
 338         }
 339         return inode;
 340 }
 341
 342 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 343                 int fh_len, int fh_type)
 344 {
 345         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 346                                     ext2_nfs_get_inode);
 347 }
 348
 349 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 350                 int fh_len, int fh_type)
 351 {
 352         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 353                                     ext2_nfs_get_inode);
 354 }
 355
 356 /* Yes, most of these are left as NULL!!
 357  * A NULL value implies the default, which works with ext2-like file
 358  * systems, but can be improved upon.
 359  * Currently only get_parent is required.
 360  */
 361 static const struct export_operations ext2_export_ops = {
 362         .fh_to_dentry = ext2_fh_to_dentry,
 363         .fh_to_parent = ext2_fh_to_parent,
 364         .get_parent = ext2_get_parent,
 365 };
 366
 367 static unsigned long get_sb_block(void **data)
 368 {
 369         unsigned long   sb_block;
 370         char            *options = (char *) *data;
 371
 372         if (!options || strncmp(options, "sb=", 3) != 0)
 373                 return 1;       /* Default location */
 374         options += 3;
 375         sb_block = simple_strtoul(options, &options, 0);
 376         if (*options && *options != ',') {
 377                 printk("EXT2-fs: Invalid sb specification: %s\n",
 378                        (char *) *data);
 379                 return 1;
 380         }
 381         if (*options == ',')
 382                 options++;
 383         *data = (void *) options;
 384         return sb_block;
 385 }
 386
 387 enum {
 388         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 389         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 390         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 391         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 392         Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 393         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 394 };
 395
 396 static const match_table_t tokens = {
 397         {Opt_bsd_df, "bsddf"},
 398         {Opt_minix_df, "minixdf"},
 399         {Opt_grpid, "grpid"},
 400         {Opt_grpid, "bsdgroups"},
 401         {Opt_nogrpid, "nogrpid"},
 402         {Opt_nogrpid, "sysvgroups"},
 403         {Opt_resgid, "resgid=%u"},
 404         {Opt_resuid, "resuid=%u"},
 405         {Opt_sb, "sb=%u"},
 406         {Opt_err_cont, "errors=continue"},
 407         {Opt_err_panic, "errors=panic"},
 408         {Opt_err_ro, "errors=remount-ro"},
 409         {Opt_nouid32, "nouid32"},
 410         {Opt_nocheck, "check=none"},
 411         {Opt_nocheck, "nocheck"},
 412         {Opt_debug, "debug"},
 413         {Opt_oldalloc, "oldalloc"},
 414         {Opt_orlov, "orlov"},
 415         {Opt_nobh, "nobh"},
 416         {Opt_user_xattr, "user_xattr"},
 417         {Opt_nouser_xattr, "nouser_xattr"},
 418         {Opt_acl, "acl"},
 419         {Opt_noacl, "noacl"},
 420         {Opt_xip, "xip"},
 421         {Opt_grpquota, "grpquota"},
 422         {Opt_ignore, "noquota"},
 423         {Opt_quota, "quota"},
 424         {Opt_usrquota, "usrquota"},
 425         {Opt_reservation, "reservation"},
 426         {Opt_noreservation, "noreservation"},
 427         {Opt_err, NULL}
 428 };
 429
 430 static int parse_options(char *options, struct super_block *sb)
 431 {
 432         char *p;
 433         struct ext2_sb_info *sbi = EXT2_SB(sb);
 434         substring_t args[MAX_OPT_ARGS];
 435         int option;
 436
 437         if (!options)
 438                 return 1;
 439
 440         while ((p = strsep (&options, ",")) != NULL) {
 441                 int token;
 442                 if (!*p)
 443                         continue;
 444
 445                 token = match_token(p, tokens, args);
 446                 switch (token) {
 447                 case Opt_bsd_df:
 448                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 449                         break;
 450                 case Opt_minix_df:
 451                         set_opt (sbi->s_mount_opt, MINIX_DF);
 452                         break;
 453                 case Opt_grpid:
 454                         set_opt (sbi->s_mount_opt, GRPID);
 455                         break;
 456                 case Opt_nogrpid:
 457                         clear_opt (sbi->s_mount_opt, GRPID);
 458                         break;
 459                 case Opt_resuid:
 460                         if (match_int(&args[0], &option))
 461                                 return 0;
 462                         sbi->s_resuid = option;
 463                         break;
 464                 case Opt_resgid:
 465                         if (match_int(&args[0], &option))
 466                                 return 0;
 467                         sbi->s_resgid = option;
 468                         break;
 469                 case Opt_sb:
 470                         /* handled by get_sb_block() instead of here */
 471                         /* *sb_block = match_int(&args[0]); */
 472                         break;
 473                 case Opt_err_panic:
 474                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 475                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 476                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 477                         break;
 478                 case Opt_err_ro:
 479                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 480                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 481                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 482                         break;
 483                 case Opt_err_cont:
 484                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 485                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 486                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 487                         break;
 488                 case Opt_nouid32:
 489                         set_opt (sbi->s_mount_opt, NO_UID32);
 490                         break;
 491                 case Opt_nocheck:
 492                         clear_opt (sbi->s_mount_opt, CHECK);
 493                         break;
 494                 case Opt_debug:
 495                         set_opt (sbi->s_mount_opt, DEBUG);
 496                         break;
 497                 case Opt_oldalloc:
 498                         set_opt (sbi->s_mount_opt, OLDALLOC);
 499                         break;
 500                 case Opt_orlov:
 501                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 502                         break;
 503                 case Opt_nobh:
 504                         set_opt (sbi->s_mount_opt, NOBH);
 505                         break;
 506 #ifdef CONFIG_EXT2_FS_XATTR
 507                 case Opt_user_xattr:
 508                         set_opt (sbi->s_mount_opt, XATTR_USER);
 509                         break;
 510                 case Opt_nouser_xattr:
 511                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 512                         break;
 513 #else
 514                 case Opt_user_xattr:
 515                 case Opt_nouser_xattr:
 516                         ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 517                                 "not supported");
 518                         break;
 519 #endif
 520 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 521                 case Opt_acl:
 522                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 523                         break;
 524                 case Opt_noacl:
 525                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 526                         break;
 527 #else
 528                 case Opt_acl:
 529                 case Opt_noacl:
 530                         ext2_msg(sb, KERN_INFO,
 531                                 "(no)acl options not supported");
 532                         break;
 533 #endif
 534                 case Opt_xip:
 535 #ifdef CONFIG_EXT2_FS_XIP
 536                         set_opt (sbi->s_mount_opt, XIP);
 537 #else
 538                         ext2_msg(sb, KERN_INFO, "xip option not supported");
 539 #endif
 540                         break;
 541
 542 #if defined(CONFIG_QUOTA)
 543                 case Opt_quota:
 544                 case Opt_usrquota:
 545                         set_opt(sbi->s_mount_opt, USRQUOTA);
 546                         break;
 547
 548                 case Opt_grpquota:
 549                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 550                         break;
 551 #else
 552                 case Opt_quota:
 553                 case Opt_usrquota:
 554                 case Opt_grpquota:
 555                         ext2_msg(sb, KERN_INFO,
 556                                 "quota operations not supported");
 557                         break;
 558 #endif
 559
 560                 case Opt_reservation:
 561                         set_opt(sbi->s_mount_opt, RESERVATION);
 562                         ext2_msg(sb, KERN_INFO, "reservations ON");
 563                         break;
 564                 case Opt_noreservation:
 565                         clear_opt(sbi->s_mount_opt, RESERVATION);
 566                         ext2_msg(sb, KERN_INFO, "reservations OFF");
 567                         break;
 568                 case Opt_ignore:
 569                         break;
 570                 default:
 571                         return 0;
 572                 }
 573         }
 574         return 1;
 575 }
 576
 577 static int ext2_setup_super (struct super_block * sb,
 578                               struct ext2_super_block * es,
 579                               int read_only)
 580 {
 581         int res = 0;
 582         struct ext2_sb_info *sbi = EXT2_SB(sb);
 583
 584         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 585                 ext2_msg(sb, KERN_ERR,
 586                         "error: revision level too high, "
 587                         "forcing read-only mode");
 588                 res = MS_RDONLY;
 589         }
 590         if (read_only)
 591                 return res;
 592         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 593                 ext2_msg(sb, KERN_WARNING,
 594                         "warning: mounting unchecked fs, "
 595                         "running e2fsck is recommended");
 596         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 597                 ext2_msg(sb, KERN_WARNING,
 598                         "warning: mounting fs with errors, "
 599                         "running e2fsck is recommended");
 600         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 601                  le16_to_cpu(es->s_mnt_count) >=
 602                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 603                 ext2_msg(sb, KERN_WARNING,
 604                         "warning: maximal mount count reached, "
 605                         "running e2fsck is recommended");
 606         else if (le32_to_cpu(es->s_checkinterval) &&
 607                 (le32_to_cpu(es->s_lastcheck) +
 608                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 609                 ext2_msg(sb, KERN_WARNING,
 610                         "warning: checktime reached, "
 611                         "running e2fsck is recommended");
 612         if (!le16_to_cpu(es->s_max_mnt_count))
 613                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 614         le16_add_cpu(&es->s_mnt_count, 1);
 615         if (test_opt (sb, DEBUG))
 616                 ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 617                         "bpg=%lu, ipg=%lu, mo=%04lx]",
 618                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 619                         sbi->s_frag_size,
 620                         sbi->s_groups_count,
 621                         EXT2_BLOCKS_PER_GROUP(sb),
 622                         EXT2_INODES_PER_GROUP(sb),
 623                         sbi->s_mount_opt);
 624         return res;
 625 }
 626
 627 static int ext2_check_descriptors(struct super_block *sb)
 628 {
 629         int i;
 630         struct ext2_sb_info *sbi = EXT2_SB(sb);
 631
 632         ext2_debug ("Checking group descriptors");
 633
 634         for (i = 0; i < sbi->s_groups_count; i++) {
 635                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 636                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 637                 ext2_fsblk_t last_block;
 638
 639                 if (i == sbi->s_groups_count - 1)
 640                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 641                 else
 642                         last_block = first_block +
 643                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 644
 645                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 646                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 647                 {
 648                         ext2_error (sb, "ext2_check_descriptors",
 649                                     "Block bitmap for group %d"
 650                                     " not in group (block %lu)!",
 651                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 652                         return 0;
 653                 }
 654                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 655                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 656                 {
 657                         ext2_error (sb, "ext2_check_descriptors",
 658                                     "Inode bitmap for group %d"
 659                                     " not in group (block %lu)!",
 660                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 661                         return 0;
 662                 }
 663                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 664                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 665                     last_block)
 666                 {
 667                         ext2_error (sb, "ext2_check_descriptors",
 668                                     "Inode table for group %d"
 669                                     " not in group (block %lu)!",
 670                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 671                         return 0;
 672                 }
 673         }
 674         return 1;
 675 }
 676
 677 /*
 678  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 679  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 680  * We need to be 1 filesystem block less than the 2^32 sector limit.
 681  */
 682 static loff_t ext2_max_size(int bits)
 683 {
 684         loff_t res = EXT2_NDIR_BLOCKS;
 685         int meta_blocks;
 686         loff_t upper_limit;
 687
 688         /* This is calculated to be the largest file size for a
 689          * dense, file such that the total number of
 690          * sectors in the file, including data and all indirect blocks,
 691          * does not exceed 2^32 -1
 692          * __u32 i_blocks representing the total number of
 693          * 512 bytes blocks of the file
 694          */
 695         upper_limit = (1LL << 32) - 1;
 696
 697         /* total blocks in file system block size */
 698         upper_limit >>= (bits - 9);
 699
 700
 701         /* indirect blocks */
 702         meta_blocks = 1;
 703         /* double indirect blocks */
 704         meta_blocks += 1 + (1LL << (bits-2));
 705         /* tripple indirect blocks */
 706         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 707
 708         upper_limit -= meta_blocks;
 709         upper_limit <<= bits;
 710
 711         res += 1LL << (bits-2);
 712         res += 1LL << (2*(bits-2));
 713         res += 1LL << (3*(bits-2));
 714         res <<= bits;
 715         if (res > upper_limit)
 716                 res = upper_limit;
 717
 718         if (res > MAX_LFS_FILESIZE)
 719                 res = MAX_LFS_FILESIZE;
 720
 721         return res;
 722 }
 723
 724 static unsigned long descriptor_loc(struct super_block *sb,
 725                                     unsigned long logic_sb_block,
 726                                     int nr)
 727 {
 728         struct ext2_sb_info *sbi = EXT2_SB(sb);
 729         unsigned long bg, first_meta_bg;
 730         int has_super = 0;
 731
 732         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 733
 734         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 735             nr < first_meta_bg)
 736                 return (logic_sb_block + nr + 1);
 737         bg = sbi->s_desc_per_block * nr;
 738         if (ext2_bg_has_super(sb, bg))
 739                 has_super = 1;
 740
 741         return ext2_group_first_block_no(sb, bg) + has_super;
 742 }
 743
 744 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 745 {
 746         struct buffer_head * bh;
 747         struct ext2_sb_info * sbi;
 748         struct ext2_super_block * es;
 749         struct inode *root;
 750         unsigned long block;
 751         unsigned long sb_block = get_sb_block(&data);
 752         unsigned long logic_sb_block;
 753         unsigned long offset = 0;
 754         unsigned long def_mount_opts;
 755         long ret = -EINVAL;
 756         int blocksize = BLOCK_SIZE;
 757         int db_count;
 758         int i, j;
 759         __le32 features;
 760         int err;
 761
 762         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 763         if (!sbi)
 764                 return -ENOMEM;
 765
 766         sbi->s_blockgroup_lock =
 767                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 768         if (!sbi->s_blockgroup_lock) {
 769                 kfree(sbi);
 770                 return -ENOMEM;
 771         }
 772         sb->s_fs_info = sbi;
 773         sbi->s_sb_block = sb_block;
 774
 775         spin_lock_init(&sbi->s_lock);
 776
 777         /*
 778          * See what the current blocksize for the device is, and
 779          * use that as the blocksize.  Otherwise (or if the blocksize
 780          * is smaller than the default) use the default.
 781          * This is important for devices that have a hardware
 782          * sectorsize that is larger than the default.
 783          */
 784         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 785         if (!blocksize) {
 786                 ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 787                 goto failed_sbi;
 788         }
 789
 790         /*
 791          * If the superblock doesn't start on a hardware sector boundary,
 792          * calculate the offset.
 793          */
 794         if (blocksize != BLOCK_SIZE) {
 795                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 796                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 797         } else {
 798                 logic_sb_block = sb_block;
 799         }
 800
 801         if (!(bh = sb_bread(sb, logic_sb_block))) {
 802                 ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 803                 goto failed_sbi;
 804         }
 805         /*
 806          * Note: s_es must be initialized as soon as possible because
 807          *       some ext2 macro-instructions depend on its value
 808          */
 809         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 810         sbi->s_es = es;
 811         sb->s_magic = le16_to_cpu(es->s_magic);
 812
 813         if (sb->s_magic != EXT2_SUPER_MAGIC)
 814                 goto cantfind_ext2;
 815
 816         /* Set defaults before we parse the mount options */
 817         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 818         if (def_mount_opts & EXT2_DEFM_DEBUG)
 819                 set_opt(sbi->s_mount_opt, DEBUG);
 820         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 821                 set_opt(sbi->s_mount_opt, GRPID);
 822         if (def_mount_opts & EXT2_DEFM_UID16)
 823                 set_opt(sbi->s_mount_opt, NO_UID32);
 824 #ifdef CONFIG_EXT2_FS_XATTR
 825         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 826                 set_opt(sbi->s_mount_opt, XATTR_USER);
 827 #endif
 828 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 829         if (def_mount_opts & EXT2_DEFM_ACL)
 830                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 831 #endif
 832
 833         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 834                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 835         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 836                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 837         else
 838                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 839
 840         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 841         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 842
 843         set_opt(sbi->s_mount_opt, RESERVATION);
 844
 845         if (!parse_options((char *) data, sb))
 846                 goto failed_mount;
 847
 848         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 849                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 850                  MS_POSIXACL : 0);
 851
 852         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 853                                     EXT2_MOUNT_XIP if not */
 854
 855         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 856             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 857              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 858              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 859                 ext2_msg(sb, KERN_WARNING,
 860                         "warning: feature flags set on rev 0 fs, "
 861                         "running e2fsck is recommended");
 862         /*
 863          * Check feature flags regardless of the revision level, since we
 864          * previously didn't change the revision level when setting the flags,
 865          * so there is a chance incompat flags are set on a rev 0 filesystem.
 866          */
 867         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 868         if (features) {
 869                 ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 870                        "unsupported optional features (%x)",
 871                         le32_to_cpu(features));
 872                 goto failed_mount;
 873         }
 874         if (!(sb->s_flags & MS_RDONLY) &&
 875             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 876                 ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 877                        "unsupported optional features (%x)",
 878                        le32_to_cpu(features));
 879                 goto failed_mount;
 880         }
 881
 882         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 883
 884         if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
 885                 if (!silent)
 886                         ext2_msg(sb, KERN_ERR,
 887                                 "error: unsupported blocksize for xip");
 888                 goto failed_mount;
 889         }
 890
 891         /* If the blocksize doesn't match, re-read the thing.. */
 892         if (sb->s_blocksize != blocksize) {
 893                 brelse(bh);
 894
 895                 if (!sb_set_blocksize(sb, blocksize)) {
 896                         ext2_msg(sb, KERN_ERR, "error: blocksize is too small");
 897                         goto failed_sbi;
 898                 }
 899
 900                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 901                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 902                 bh = sb_bread(sb, logic_sb_block);
 903                 if(!bh) {
 904                         ext2_msg(sb, KERN_ERR, "error: couldn't read"
 905                                 "superblock on 2nd try");
 906                         goto failed_sbi;
 907                 }
 908                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 909                 sbi->s_es = es;
 910                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 911                         ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 912                         goto failed_mount;
 913                 }
 914         }
 915
 916         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 917
 918         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 919                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 920                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 921         } else {
 922                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 923                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 924                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 925                     !is_power_of_2(sbi->s_inode_size) ||
 926                     (sbi->s_inode_size > blocksize)) {
 927                         ext2_msg(sb, KERN_ERR,
 928                                 "error: unsupported inode size: %d",
 929                                 sbi->s_inode_size);
 930                         goto failed_mount;
 931                 }
 932         }
 933
 934         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 935                                    le32_to_cpu(es->s_log_frag_size);
 936         if (sbi->s_frag_size == 0)
 937                 goto cantfind_ext2;
 938         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 939
 940         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 941         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 942         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 943
 944         if (EXT2_INODE_SIZE(sb) == 0)
 945                 goto cantfind_ext2;
 946         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 947         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 948                 goto cantfind_ext2;
 949         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 950                                         sbi->s_inodes_per_block;
 951         sbi->s_desc_per_block = sb->s_blocksize /
 952                                         sizeof (struct ext2_group_desc);
 953         sbi->s_sbh = bh;
 954         sbi->s_mount_state = le16_to_cpu(es->s_state);
 955         sbi->s_addr_per_block_bits =
 956                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 957         sbi->s_desc_per_block_bits =
 958                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
 959
 960         if (sb->s_magic != EXT2_SUPER_MAGIC)
 961                 goto cantfind_ext2;
 962
 963         if (sb->s_blocksize != bh->b_size) {
 964                 if (!silent)
 965                         ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
 966                 goto failed_mount;
 967         }
 968
 969         if (sb->s_blocksize != sbi->s_frag_size) {
 970                 ext2_msg(sb, KERN_ERR,
 971                         "error: fragsize %lu != blocksize %lu"
 972                         "(not supported yet)",
 973                         sbi->s_frag_size, sb->s_blocksize);
 974                 goto failed_mount;
 975         }
 976
 977         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 978                 ext2_msg(sb, KERN_ERR,
 979                         "error: #blocks per group too big: %lu",
 980                         sbi->s_blocks_per_group);
 981                 goto failed_mount;
 982         }
 983         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 984                 ext2_msg(sb, KERN_ERR,
 985                         "error: #fragments per group too big: %lu",
 986                         sbi->s_frags_per_group);
 987                 goto failed_mount;
 988         }
 989         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 990                 ext2_msg(sb, KERN_ERR,
 991                         "error: #inodes per group too big: %lu",
 992                         sbi->s_inodes_per_group);
 993                 goto failed_mount;
 994         }
 995
 996         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 997                 goto cantfind_ext2;
 998         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
 999                                 le32_to_cpu(es->s_first_data_block) - 1)
1000                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1001         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1002                    EXT2_DESC_PER_BLOCK(sb);
1003         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1004         if (sbi->s_group_desc == NULL) {
1005                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1006                 goto failed_mount;
1007         }
1008         bgl_lock_init(sbi->s_blockgroup_lock);
1009         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1010         if (!sbi->s_debts) {
1011                 ext2_msg(sb, KERN_ERR, "error: not enough memory");
1012                 goto failed_mount_group_desc;
1013         }
1014         for (i = 0; i < db_count; i++) {
1015                 block = descriptor_loc(sb, logic_sb_block, i);
1016                 sbi->s_group_desc[i] = sb_bread(sb, block);
1017                 if (!sbi->s_group_desc[i]) {
1018                         for (j = 0; j < i; j++)
1019                                 brelse (sbi->s_group_desc[j]);
1020                         ext2_msg(sb, KERN_ERR,
1021                                 "error: unable to read group descriptors");
1022                         goto failed_mount_group_desc;
1023                 }
1024         }
1025         if (!ext2_check_descriptors (sb)) {
1026                 ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1027                 goto failed_mount2;
1028         }
1029         sbi->s_gdb_count = db_count;
1030         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1031         spin_lock_init(&sbi->s_next_gen_lock);
1032
1033         /* per fileystem reservation list head & lock */
1034         spin_lock_init(&sbi->s_rsv_window_lock);
1035         sbi->s_rsv_window_root = RB_ROOT;
1036         /*
1037          * Add a single, static dummy reservation to the start of the
1038          * reservation window list --- it gives us a placeholder for
1039          * append-at-start-of-list which makes the allocation logic
1040          * _much_ simpler.
1041          */
1042         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1043         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1044         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1045         sbi->s_rsv_window_head.rsv_goal_size = 0;
1046         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1047
1048         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1049                                 ext2_count_free_blocks(sb));
1050         if (!err) {
1051                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1052                                 ext2_count_free_inodes(sb));
1053         }
1054         if (!err) {
1055                 err = percpu_counter_init(&sbi->s_dirs_counter,
1056                                 ext2_count_dirs(sb));
1057         }
1058         if (err) {
1059                 ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1060                 goto failed_mount3;
1061         }
1062         /*
1063          * set up enough so that it can read an inode
1064          */
1065         sb->s_op = &ext2_sops;
1066         sb->s_export_op = &ext2_export_ops;
1067         sb->s_xattr = ext2_xattr_handlers;
1068         root = ext2_iget(sb, EXT2_ROOT_INO);
1069         if (IS_ERR(root)) {
1070                 ret = PTR_ERR(root);
1071                 goto failed_mount3;
1072         }
1073         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1074                 iput(root);
1075                 ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1076                 goto failed_mount3;
1077         }
1078
1079         sb->s_root = d_alloc_root(root);
1080         if (!sb->s_root) {
1081                 iput(root);
1082                 ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1083                 ret = -ENOMEM;
1084                 goto failed_mount3;
1085         }
1086         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1087                 ext2_msg(sb, KERN_WARNING,
1088                         "warning: mounting ext3 filesystem as ext2");
1089         if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1090                 sb->s_flags |= MS_RDONLY;
1091         ext2_write_super(sb);
1092         return 0;
1093
1094 cantfind_ext2:
1095         if (!silent)
1096                 ext2_msg(sb, KERN_ERR,
1097                         "error: can't find an ext2 filesystem on dev %s.",
1098                         sb->s_id);
1099         goto failed_mount;
1100 failed_mount3:
1101         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1102         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1103         percpu_counter_destroy(&sbi->s_dirs_counter);
1104 failed_mount2:
1105         for (i = 0; i < db_count; i++)
1106                 brelse(sbi->s_group_desc[i]);
1107 failed_mount_group_desc:
1108         kfree(sbi->s_group_desc);
1109         kfree(sbi->s_debts);
1110 failed_mount:
1111         brelse(bh);
1112 failed_sbi:
1113         sb->s_fs_info = NULL;
1114         kfree(sbi->s_blockgroup_lock);
1115         kfree(sbi);
1116         return ret;
1117 }
1118
1119 static void ext2_clear_super_error(struct super_block *sb)
1120 {
1121         struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1122
1123         if (buffer_write_io_error(sbh)) {
1124                 /*
1125                  * Oh, dear.  A previous attempt to write the
1126                  * superblock failed.  This could happen because the
1127                  * USB device was yanked out.  Or it could happen to
1128                  * be a transient write error and maybe the block will
1129                  * be remapped.  Nothing we can do but to retry the
1130                  * write and hope for the best.
1131                  */
1132                 ext2_msg(sb, KERN_ERR,
1133                        "previous I/O error to superblock detected\n");
1134                 clear_buffer_write_io_error(sbh);
1135                 set_buffer_uptodate(sbh);
1136         }
1137 }
1138
1139 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1140                             int wait)
1141 {
1142         ext2_clear_super_error(sb);
1143         spin_lock(&EXT2_SB(sb)->s_lock);
1144         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1145         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1146         es->s_wtime = cpu_to_le32(get_seconds());
1147         /* unlock before we do IO */
1148         spin_unlock(&EXT2_SB(sb)->s_lock);
1149         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1150         if (wait)
1151                 sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1152         sb->s_dirt = 0;
1153 }
1154
1155 /*
1156  * In the second extended file system, it is not necessary to
1157  * write the super block since we use a mapping of the
1158  * disk super block in a buffer.
1159  *
1160  * However, this function is still used to set the fs valid
1161  * flags to 0.  We need to set this flag to 0 since the fs
1162  * may have been checked while mounted and e2fsck may have
1163  * set s_state to EXT2_VALID_FS after some corrections.
1164  */
1165 static int ext2_sync_fs(struct super_block *sb, int wait)
1166 {
1167         struct ext2_sb_info *sbi = EXT2_SB(sb);
1168         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1169
1170         spin_lock(&sbi->s_lock);
1171         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1172                 ext2_debug("setting valid to 0\n");
1173                 es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1174         }
1175         spin_unlock(&sbi->s_lock);
1176         ext2_sync_super(sb, es, wait);
1177         return 0;
1178 }
1179
1180
1181 void ext2_write_super(struct super_block *sb)
1182 {
1183         if (!(sb->s_flags & MS_RDONLY))
1184                 ext2_sync_fs(sb, 1);
1185         else
1186                 sb->s_dirt = 0;
1187 }
1188
1189 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1190 {
1191         struct ext2_sb_info * sbi = EXT2_SB(sb);
1192         struct ext2_super_block * es;
1193         unsigned long old_mount_opt = sbi->s_mount_opt;
1194         struct ext2_mount_options old_opts;
1195         unsigned long old_sb_flags;
1196         int err;
1197
1198         spin_lock(&sbi->s_lock);
1199
1200         /* Store the old options */
1201         old_sb_flags = sb->s_flags;
1202         old_opts.s_mount_opt = sbi->s_mount_opt;
1203         old_opts.s_resuid = sbi->s_resuid;
1204         old_opts.s_resgid = sbi->s_resgid;
1205
1206         /*
1207          * Allow the "check" option to be passed as a remount option.
1208          */
1209         if (!parse_options(data, sb)) {
1210                 err = -EINVAL;
1211                 goto restore_opts;
1212         }
1213
1214         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1215                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1216
1217         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1218                                     EXT2_MOUNT_XIP if not */
1219
1220         if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1221                 ext2_msg(sb, KERN_WARNING,
1222                         "warning: unsupported blocksize for xip");
1223                 err = -EINVAL;
1224                 goto restore_opts;
1225         }
1226
1227         es = sbi->s_es;
1228         if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1229             (old_mount_opt & EXT2_MOUNT_XIP)) &&
1230             invalidate_inodes(sb)) {
1231                 ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1232                          "xip flag with busy inodes while remounting");
1233                 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1234                 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1235         }
1236         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1237                 spin_unlock(&sbi->s_lock);
1238                 return 0;
1239         }
1240         if (*flags & MS_RDONLY) {
1241                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1242                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
1243                         spin_unlock(&sbi->s_lock);
1244                         return 0;
1245                 }
1246
1247                 /*
1248                  * OK, we are remounting a valid rw partition rdonly, so set
1249                  * the rdonly flag and then mark the partition as valid again.
1250                  */
1251                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1252                 es->s_mtime = cpu_to_le32(get_seconds());
1253                 spin_unlock(&sbi->s_lock);
1254
1255                 err = dquot_suspend(sb, -1);
1256                 if (err < 0) {
1257                         spin_lock(&sbi->s_lock);
1258                         goto restore_opts;
1259                 }
1260
1261                 ext2_sync_super(sb, es, 1);
1262         } else {
1263                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1264                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1265                 if (ret) {
1266                         ext2_msg(sb, KERN_WARNING,
1267                                 "warning: couldn't remount RDWR because of "
1268                                 "unsupported optional features (%x).",
1269                                 le32_to_cpu(ret));
1270                         err = -EROFS;
1271                         goto restore_opts;
1272                 }
1273                 /*
1274                  * Mounting a RDONLY partition read-write, so reread and
1275                  * store the current valid flag.  (It may have been changed
1276                  * by e2fsck since we originally mounted the partition.)
1277                  */
1278                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1279                 if (!ext2_setup_super (sb, es, 0))
1280                         sb->s_flags &= ~MS_RDONLY;
1281                 spin_unlock(&sbi->s_lock);
1282
1283                 ext2_write_super(sb);
1284
1285                 dquot_resume(sb, -1);
1286         }
1287
1288         return 0;
1289 restore_opts:
1290         sbi->s_mount_opt = old_opts.s_mount_opt;
1291         sbi->s_resuid = old_opts.s_resuid;
1292         sbi->s_resgid = old_opts.s_resgid;
1293         sb->s_flags = old_sb_flags;
1294         spin_unlock(&sbi->s_lock);
1295         return err;
1296 }
1297
1298 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1299 {
1300         struct super_block *sb = dentry->d_sb;
1301         struct ext2_sb_info *sbi = EXT2_SB(sb);
1302         struct ext2_super_block *es = sbi->s_es;
1303         u64 fsid;
1304
1305         spin_lock(&sbi->s_lock);
1306
1307         if (test_opt (sb, MINIX_DF))
1308                 sbi->s_overhead_last = 0;
1309         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1310                 unsigned long i, overhead = 0;
1311                 smp_rmb();
1312
1313                 /*
1314                  * Compute the overhead (FS structures). This is constant
1315                  * for a given filesystem unless the number of block groups
1316                  * changes so we cache the previous value until it does.
1317                  */
1318
1319                 /*
1320                  * All of the blocks before first_data_block are
1321                  * overhead
1322                  */
1323                 overhead = le32_to_cpu(es->s_first_data_block);
1324
1325                 /*
1326                  * Add the overhead attributed to the superblock and
1327                  * block group descriptors.  If the sparse superblocks
1328                  * feature is turned on, then not all groups have this.
1329                  */
1330                 for (i = 0; i < sbi->s_groups_count; i++)
1331                         overhead += ext2_bg_has_super(sb, i) +
1332                                 ext2_bg_num_gdb(sb, i);
1333
1334                 /*
1335                  * Every block group has an inode bitmap, a block
1336                  * bitmap, and an inode table.
1337                  */
1338                 overhead += (sbi->s_groups_count *
1339                              (2 + sbi->s_itb_per_group));
1340                 sbi->s_overhead_last = overhead;
1341                 smp_wmb();
1342                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1343         }
1344
1345         buf->f_type = EXT2_SUPER_MAGIC;
1346         buf->f_bsize = sb->s_blocksize;
1347         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1348         buf->f_bfree = ext2_count_free_blocks(sb);
1349         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1350         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1351         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1352                 buf->f_bavail = 0;
1353         buf->f_files = le32_to_cpu(es->s_inodes_count);
1354         buf->f_ffree = ext2_count_free_inodes(sb);
1355         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1356         buf->f_namelen = EXT2_NAME_LEN;
1357         fsid = le64_to_cpup((void *)es->s_uuid) ^
1358                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1359         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1360         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1361         spin_unlock(&sbi->s_lock);
1362         return 0;
1363 }
1364
1365 static int ext2_get_sb(struct file_system_type *fs_type,
1366         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1367 {
1368         return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1369 }
1370
1371 #ifdef CONFIG_QUOTA
1372
1373 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1374  * acquiring the locks... As quota files are never truncated and quota code
1375  * itself serializes the operations (and noone else should touch the files)
1376  * we don't have to be afraid of races */
1377 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1378                                size_t len, loff_t off)
1379 {
1380         struct inode *inode = sb_dqopt(sb)->files[type];
1381         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1382         int err = 0;
1383         int offset = off & (sb->s_blocksize - 1);
1384         int tocopy;
1385         size_t toread;
1386         struct buffer_head tmp_bh;
1387         struct buffer_head *bh;
1388         loff_t i_size = i_size_read(inode);
1389
1390         if (off > i_size)
1391                 return 0;
1392         if (off+len > i_size)
1393                 len = i_size-off;
1394         toread = len;
1395         while (toread > 0) {
1396                 tocopy = sb->s_blocksize - offset < toread ?
1397                                 sb->s_blocksize - offset : toread;
1398
1399                 tmp_bh.b_state = 0;
1400                 tmp_bh.b_size = sb->s_blocksize;
1401                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1402                 if (err < 0)
1403                         return err;
1404                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1405                         memset(data, 0, tocopy);
1406                 else {
1407                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1408                         if (!bh)
1409                                 return -EIO;
1410                         memcpy(data, bh->b_data+offset, tocopy);
1411                         brelse(bh);
1412                 }
1413                 offset = 0;
1414                 toread -= tocopy;
1415                 data += tocopy;
1416                 blk++;
1417         }
1418         return len;
1419 }
1420
1421 /* Write to quotafile */
1422 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1423                                 const char *data, size_t len, loff_t off)
1424 {
1425         struct inode *inode = sb_dqopt(sb)->files[type];
1426         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1427         int err = 0;
1428         int offset = off & (sb->s_blocksize - 1);
1429         int tocopy;
1430         size_t towrite = len;
1431         struct buffer_head tmp_bh;
1432         struct buffer_head *bh;
1433
1434         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1435         while (towrite > 0) {
1436                 tocopy = sb->s_blocksize - offset < towrite ?
1437                                 sb->s_blocksize - offset : towrite;
1438
1439                 tmp_bh.b_state = 0;
1440                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1441                 if (err < 0)
1442                         goto out;
1443                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1444                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1445                 else
1446                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1447                 if (!bh) {
1448                         err = -EIO;
1449                         goto out;
1450                 }
1451                 lock_buffer(bh);
1452                 memcpy(bh->b_data+offset, data, tocopy);
1453                 flush_dcache_page(bh->b_page);
1454                 set_buffer_uptodate(bh);
1455                 mark_buffer_dirty(bh);
1456                 unlock_buffer(bh);
1457                 brelse(bh);
1458                 offset = 0;
1459                 towrite -= tocopy;
1460                 data += tocopy;
1461                 blk++;
1462         }
1463 out:
1464         if (len == towrite) {
1465                 mutex_unlock(&inode->i_mutex);
1466                 return err;
1467         }
1468         if (inode->i_size < off+len-towrite)
1469                 i_size_write(inode, off+len-towrite);
1470         inode->i_version++;
1471         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1472         mark_inode_dirty(inode);
1473         mutex_unlock(&inode->i_mutex);
1474         return len - towrite;
1475 }
1476
1477 #endif
1478
1479 static struct file_system_type ext2_fs_type = {
1480         .owner          = THIS_MODULE,
1481         .name           = "ext2",
1482         .get_sb         = ext2_get_sb,
1483         .kill_sb        = kill_block_super,
1484         .fs_flags       = FS_REQUIRES_DEV,
1485 };
1486
1487 static int __init init_ext2_fs(void)
1488 {
1489         int err = init_ext2_xattr();
1490         if (err)
1491                 return err;
1492         err = init_inodecache();
1493         if (err)
1494                 goto out1;
1495         err = register_filesystem(&ext2_fs_type);
1496         if (err)
1497                 goto out;
1498         return 0;
1499 out:
1500         destroy_inodecache();
1501 out1:
1502         exit_ext2_xattr();
1503         return err;
1504 }
1505
1506 static void __exit exit_ext2_fs(void)
1507 {
1508         unregister_filesystem(&ext2_fs_type);
1509         destroy_inodecache();
1510         exit_ext2_xattr();
1511 }
1512
1513 module_init(init_ext2_fs)
1514 module_exit(exit_ext2_fs)