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/smp_lock.h>
  30 #include <linux/vfs.h>
  31 #include <linux/seq_file.h>
  32 #include <linux/mount.h>
  33 #include <linux/log2.h>
  34 #include <linux/quotaops.h>
  35 #include <asm/uaccess.h>
  36 #include "ext2.h"
  37 #include "xattr.h"
  38 #include "acl.h"
  39 #include "xip.h"
  40
  41 static void ext2_sync_super(struct super_block *sb,
  42                             struct ext2_super_block *es);
  43 static int ext2_remount (struct super_block * sb, int * flags, char * data);
  44 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  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                 sbi->s_mount_state |= EXT2_ERROR_FS;
  55                 es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  56                 ext2_sync_super(sb, es);
  57         }
  58
  59         va_start(args, fmt);
  60         printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
  61         vprintk(fmt, args);
  62         printk("\n");
  63         va_end(args);
  64
  65         if (test_opt(sb, ERRORS_PANIC))
  66                 panic("EXT2-fs panic from previous error\n");
  67         if (test_opt(sb, ERRORS_RO)) {
  68                 printk("Remounting filesystem read-only\n");
  69                 sb->s_flags |= MS_RDONLY;
  70         }
  71 }
  72
  73 void ext2_warning (struct super_block * sb, const char * function,
  74                    const char * fmt, ...)
  75 {
  76         va_list args;
  77
  78         va_start(args, fmt);
  79         printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
  80                sb->s_id, function);
  81         vprintk(fmt, args);
  82         printk("\n");
  83         va_end(args);
  84 }
  85
  86 void ext2_update_dynamic_rev(struct super_block *sb)
  87 {
  88         struct ext2_super_block *es = EXT2_SB(sb)->s_es;
  89
  90         if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
  91                 return;
  92
  93         ext2_warning(sb, __func__,
  94                      "updating to rev %d because of new feature flag, "
  95                      "running e2fsck is recommended",
  96                      EXT2_DYNAMIC_REV);
  97
  98         es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
  99         es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 100         es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 101         /* leave es->s_feature_*compat flags alone */
 102         /* es->s_uuid will be set by e2fsck if empty */
 103
 104         /*
 105          * The rest of the superblock fields should be zero, and if not it
 106          * means they are likely already in use, so leave them alone.  We
 107          * can leave it up to e2fsck to clean up any inconsistencies there.
 108          */
 109 }
 110
 111 static void ext2_put_super (struct super_block * sb)
 112 {
 113         int db_count;
 114         int i;
 115         struct ext2_sb_info *sbi = EXT2_SB(sb);
 116
 117         ext2_xattr_put_super(sb);
 118         if (!(sb->s_flags & MS_RDONLY)) {
 119                 struct ext2_super_block *es = sbi->s_es;
 120
 121                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 122                 ext2_sync_super(sb, es);
 123         }
 124         db_count = sbi->s_gdb_count;
 125         for (i = 0; i < db_count; i++)
 126                 if (sbi->s_group_desc[i])
 127                         brelse (sbi->s_group_desc[i]);
 128         kfree(sbi->s_group_desc);
 129         kfree(sbi->s_debts);
 130         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 131         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 132         percpu_counter_destroy(&sbi->s_dirs_counter);
 133         brelse (sbi->s_sbh);
 134         sb->s_fs_info = NULL;
 135         kfree(sbi->s_blockgroup_lock);
 136         kfree(sbi);
 137
 138         return;
 139 }
 140
 141 static struct kmem_cache * ext2_inode_cachep;
 142
 143 static struct inode *ext2_alloc_inode(struct super_block *sb)
 144 {
 145         struct ext2_inode_info *ei;
 146         ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 147         if (!ei)
 148                 return NULL;
 149 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 150         ei->i_acl = EXT2_ACL_NOT_CACHED;
 151         ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 152 #endif
 153         ei->i_block_alloc_info = NULL;
 154         ei->vfs_inode.i_version = 1;
 155         return &ei->vfs_inode;
 156 }
 157
 158 static void ext2_destroy_inode(struct inode *inode)
 159 {
 160         remove_extent_mappings(&EXT2_I(inode)->extent_tree, 0, (u64)-1);
 161         kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 162 }
 163
 164 static void init_once(void *foo)
 165 {
 166         struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 167
 168         rwlock_init(&ei->i_meta_lock);
 169 #ifdef CONFIG_EXT2_FS_XATTR
 170         init_rwsem(&ei->xattr_sem);
 171 #endif
 172         mutex_init(&ei->truncate_mutex);
 173         extent_map_tree_init(&ei->extent_tree);
 174         inode_init_once(&ei->vfs_inode);
 175 }
 176
 177 static int init_inodecache(void)
 178 {
 179         ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 180                                              sizeof(struct ext2_inode_info),
 181                                              0, (SLAB_RECLAIM_ACCOUNT|
 182                                                 SLAB_MEM_SPREAD),
 183                                              init_once);
 184         if (ext2_inode_cachep == NULL)
 185                 return -ENOMEM;
 186         return 0;
 187 }
 188
 189 static void destroy_inodecache(void)
 190 {
 191         kmem_cache_destroy(ext2_inode_cachep);
 192 }
 193
 194 static void ext2_clear_inode(struct inode *inode)
 195 {
 196         struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
 197 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 198         struct ext2_inode_info *ei = EXT2_I(inode);
 199
 200         if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
 201                 posix_acl_release(ei->i_acl);
 202                 ei->i_acl = EXT2_ACL_NOT_CACHED;
 203         }
 204         if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
 205                 posix_acl_release(ei->i_default_acl);
 206                 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 207         }
 208 #endif
 209         ext2_discard_reservation(inode);
 210         EXT2_I(inode)->i_block_alloc_info = NULL;
 211         if (unlikely(rsv))
 212                 kfree(rsv);
 213 }
 214
 215 static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
 216 {
 217         struct super_block *sb = vfs->mnt_sb;
 218         struct ext2_sb_info *sbi = EXT2_SB(sb);
 219         struct ext2_super_block *es = sbi->s_es;
 220         unsigned long def_mount_opts;
 221
 222         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 223
 224         if (sbi->s_sb_block != 1)
 225                 seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 226         if (test_opt(sb, MINIX_DF))
 227                 seq_puts(seq, ",minixdf");
 228         if (test_opt(sb, GRPID))
 229                 seq_puts(seq, ",grpid");
 230         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 231                 seq_puts(seq, ",nogrpid");
 232         if (sbi->s_resuid != EXT2_DEF_RESUID ||
 233             le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 234                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 235         }
 236         if (sbi->s_resgid != EXT2_DEF_RESGID ||
 237             le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 238                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 239         }
 240         if (test_opt(sb, ERRORS_RO)) {
 241                 int def_errors = le16_to_cpu(es->s_errors);
 242
 243                 if (def_errors == EXT2_ERRORS_PANIC ||
 244                     def_errors == EXT2_ERRORS_CONTINUE) {
 245                         seq_puts(seq, ",errors=remount-ro");
 246                 }
 247         }
 248         if (test_opt(sb, ERRORS_CONT))
 249                 seq_puts(seq, ",errors=continue");
 250         if (test_opt(sb, ERRORS_PANIC))
 251                 seq_puts(seq, ",errors=panic");
 252         if (test_opt(sb, NO_UID32))
 253                 seq_puts(seq, ",nouid32");
 254         if (test_opt(sb, DEBUG))
 255                 seq_puts(seq, ",debug");
 256         if (test_opt(sb, OLDALLOC))
 257                 seq_puts(seq, ",oldalloc");
 258
 259 #ifdef CONFIG_EXT2_FS_XATTR
 260         if (test_opt(sb, XATTR_USER))
 261                 seq_puts(seq, ",user_xattr");
 262         if (!test_opt(sb, XATTR_USER) &&
 263             (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 264                 seq_puts(seq, ",nouser_xattr");
 265         }
 266 #endif
 267
 268 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 269         if (test_opt(sb, POSIX_ACL))
 270                 seq_puts(seq, ",acl");
 271         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 272                 seq_puts(seq, ",noacl");
 273 #endif
 274
 275         if (test_opt(sb, NOBH))
 276                 seq_puts(seq, ",nobh");
 277
 278 #if defined(CONFIG_QUOTA)
 279         if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 280                 seq_puts(seq, ",usrquota");
 281
 282         if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 283                 seq_puts(seq, ",grpquota");
 284 #endif
 285
 286 #if defined(CONFIG_EXT2_FS_XIP)
 287         if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 288                 seq_puts(seq, ",xip");
 289 #endif
 290
 291         if (!test_opt(sb, RESERVATION))
 292                 seq_puts(seq, ",noreservation");
 293
 294         return 0;
 295 }
 296
 297 #ifdef CONFIG_QUOTA
 298 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 299 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 300 #endif
 301
 302 static const struct super_operations ext2_sops = {
 303         .alloc_inode    = ext2_alloc_inode,
 304         .destroy_inode  = ext2_destroy_inode,
 305         .write_inode    = ext2_write_inode,
 306         .delete_inode   = ext2_delete_inode,
 307         .put_super      = ext2_put_super,
 308         .write_super    = ext2_write_super,
 309         .statfs         = ext2_statfs,
 310         .remount_fs     = ext2_remount,
 311         .clear_inode    = ext2_clear_inode,
 312         .show_options   = ext2_show_options,
 313 #ifdef CONFIG_QUOTA
 314         .quota_read     = ext2_quota_read,
 315         .quota_write    = ext2_quota_write,
 316 #endif
 317 };
 318
 319 static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 320                 u64 ino, u32 generation)
 321 {
 322         struct inode *inode;
 323
 324         if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 325                 return ERR_PTR(-ESTALE);
 326         if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 327                 return ERR_PTR(-ESTALE);
 328
 329         /* iget isn't really right if the inode is currently unallocated!!
 330          * ext2_read_inode currently does appropriate checks, but
 331          * it might be "neater" to call ext2_get_inode first and check
 332          * if the inode is valid.....
 333          */
 334         inode = ext2_iget(sb, ino);
 335         if (IS_ERR(inode))
 336                 return ERR_CAST(inode);
 337         if (generation && inode->i_generation != generation) {
 338                 /* we didn't find the right inode.. */
 339                 iput(inode);
 340                 return ERR_PTR(-ESTALE);
 341         }
 342         return inode;
 343 }
 344
 345 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 346                 int fh_len, int fh_type)
 347 {
 348         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 349                                     ext2_nfs_get_inode);
 350 }
 351
 352 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 353                 int fh_len, int fh_type)
 354 {
 355         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 356                                     ext2_nfs_get_inode);
 357 }
 358
 359 /* Yes, most of these are left as NULL!!
 360  * A NULL value implies the default, which works with ext2-like file
 361  * systems, but can be improved upon.
 362  * Currently only get_parent is required.
 363  */
 364 static const struct export_operations ext2_export_ops = {
 365         .fh_to_dentry = ext2_fh_to_dentry,
 366         .fh_to_parent = ext2_fh_to_parent,
 367         .get_parent = ext2_get_parent,
 368 };
 369
 370 static unsigned long get_sb_block(void **data)
 371 {
 372         unsigned long   sb_block;
 373         char            *options = (char *) *data;
 374
 375         if (!options || strncmp(options, "sb=", 3) != 0)
 376                 return 1;       /* Default location */
 377         options += 3;
 378         sb_block = simple_strtoul(options, &options, 0);
 379         if (*options && *options != ',') {
 380                 printk("EXT2-fs: Invalid sb specification: %s\n",
 381                        (char *) *data);
 382                 return 1;
 383         }
 384         if (*options == ',')
 385                 options++;
 386         *data = (void *) options;
 387         return sb_block;
 388 }
 389
 390 enum {
 391         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 392         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 393         Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 394         Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 395         Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 396         Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 397 };
 398
 399 static const match_table_t tokens = {
 400         {Opt_bsd_df, "bsddf"},
 401         {Opt_minix_df, "minixdf"},
 402         {Opt_grpid, "grpid"},
 403         {Opt_grpid, "bsdgroups"},
 404         {Opt_nogrpid, "nogrpid"},
 405         {Opt_nogrpid, "sysvgroups"},
 406         {Opt_resgid, "resgid=%u"},
 407         {Opt_resuid, "resuid=%u"},
 408         {Opt_sb, "sb=%u"},
 409         {Opt_err_cont, "errors=continue"},
 410         {Opt_err_panic, "errors=panic"},
 411         {Opt_err_ro, "errors=remount-ro"},
 412         {Opt_nouid32, "nouid32"},
 413         {Opt_nocheck, "check=none"},
 414         {Opt_nocheck, "nocheck"},
 415         {Opt_debug, "debug"},
 416         {Opt_oldalloc, "oldalloc"},
 417         {Opt_orlov, "orlov"},
 418         {Opt_nobh, "nobh"},
 419         {Opt_user_xattr, "user_xattr"},
 420         {Opt_nouser_xattr, "nouser_xattr"},
 421         {Opt_acl, "acl"},
 422         {Opt_noacl, "noacl"},
 423         {Opt_xip, "xip"},
 424         {Opt_grpquota, "grpquota"},
 425         {Opt_ignore, "noquota"},
 426         {Opt_quota, "quota"},
 427         {Opt_usrquota, "usrquota"},
 428         {Opt_reservation, "reservation"},
 429         {Opt_noreservation, "noreservation"},
 430         {Opt_err, NULL}
 431 };
 432
 433 static int parse_options (char * options,
 434                           struct ext2_sb_info *sbi)
 435 {
 436         char * p;
 437         substring_t args[MAX_OPT_ARGS];
 438         int option;
 439
 440         if (!options)
 441                 return 1;
 442
 443         while ((p = strsep (&options, ",")) != NULL) {
 444                 int token;
 445                 if (!*p)
 446                         continue;
 447
 448                 token = match_token(p, tokens, args);
 449                 switch (token) {
 450                 case Opt_bsd_df:
 451                         clear_opt (sbi->s_mount_opt, MINIX_DF);
 452                         break;
 453                 case Opt_minix_df:
 454                         set_opt (sbi->s_mount_opt, MINIX_DF);
 455                         break;
 456                 case Opt_grpid:
 457                         set_opt (sbi->s_mount_opt, GRPID);
 458                         break;
 459                 case Opt_nogrpid:
 460                         clear_opt (sbi->s_mount_opt, GRPID);
 461                         break;
 462                 case Opt_resuid:
 463                         if (match_int(&args[0], &option))
 464                                 return 0;
 465                         sbi->s_resuid = option;
 466                         break;
 467                 case Opt_resgid:
 468                         if (match_int(&args[0], &option))
 469                                 return 0;
 470                         sbi->s_resgid = option;
 471                         break;
 472                 case Opt_sb:
 473                         /* handled by get_sb_block() instead of here */
 474                         /* *sb_block = match_int(&args[0]); */
 475                         break;
 476                 case Opt_err_panic:
 477                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 478                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 479                         set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 480                         break;
 481                 case Opt_err_ro:
 482                         clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 483                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 484                         set_opt (sbi->s_mount_opt, ERRORS_RO);
 485                         break;
 486                 case Opt_err_cont:
 487                         clear_opt (sbi->s_mount_opt, ERRORS_RO);
 488                         clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 489                         set_opt (sbi->s_mount_opt, ERRORS_CONT);
 490                         break;
 491                 case Opt_nouid32:
 492                         set_opt (sbi->s_mount_opt, NO_UID32);
 493                         break;
 494                 case Opt_nocheck:
 495                         clear_opt (sbi->s_mount_opt, CHECK);
 496                         break;
 497                 case Opt_debug:
 498                         set_opt (sbi->s_mount_opt, DEBUG);
 499                         break;
 500                 case Opt_oldalloc:
 501                         set_opt (sbi->s_mount_opt, OLDALLOC);
 502                         break;
 503                 case Opt_orlov:
 504                         clear_opt (sbi->s_mount_opt, OLDALLOC);
 505                         break;
 506                 case Opt_nobh:
 507                         set_opt (sbi->s_mount_opt, NOBH);
 508                         break;
 509 #ifdef CONFIG_EXT2_FS_XATTR
 510                 case Opt_user_xattr:
 511                         set_opt (sbi->s_mount_opt, XATTR_USER);
 512                         break;
 513                 case Opt_nouser_xattr:
 514                         clear_opt (sbi->s_mount_opt, XATTR_USER);
 515                         break;
 516 #else
 517                 case Opt_user_xattr:
 518                 case Opt_nouser_xattr:
 519                         printk("EXT2 (no)user_xattr options not supported\n");
 520                         break;
 521 #endif
 522 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 523                 case Opt_acl:
 524                         set_opt(sbi->s_mount_opt, POSIX_ACL);
 525                         break;
 526                 case Opt_noacl:
 527                         clear_opt(sbi->s_mount_opt, POSIX_ACL);
 528                         break;
 529 #else
 530                 case Opt_acl:
 531                 case Opt_noacl:
 532                         printk("EXT2 (no)acl options not supported\n");
 533                         break;
 534 #endif
 535                 case Opt_xip:
 536 #ifdef CONFIG_EXT2_FS_XIP
 537                         set_opt (sbi->s_mount_opt, XIP);
 538 #else
 539                         printk("EXT2 xip option not supported\n");
 540 #endif
 541                         break;
 542
 543 #if defined(CONFIG_QUOTA)
 544                 case Opt_quota:
 545                 case Opt_usrquota:
 546                         set_opt(sbi->s_mount_opt, USRQUOTA);
 547                         break;
 548
 549                 case Opt_grpquota:
 550                         set_opt(sbi->s_mount_opt, GRPQUOTA);
 551                         break;
 552 #else
 553                 case Opt_quota:
 554                 case Opt_usrquota:
 555                 case Opt_grpquota:
 556                         printk(KERN_ERR
 557                                 "EXT2-fs: quota operations not supported.\n");
 558
 559                         break;
 560 #endif
 561
 562                 case Opt_reservation:
 563                         set_opt(sbi->s_mount_opt, RESERVATION);
 564                         printk("reservations ON\n");
 565                         break;
 566                 case Opt_noreservation:
 567                         clear_opt(sbi->s_mount_opt, RESERVATION);
 568                         printk("reservations OFF\n");
 569                         break;
 570                 case Opt_ignore:
 571                         break;
 572                 default:
 573                         return 0;
 574                 }
 575         }
 576         return 1;
 577 }
 578
 579 static int ext2_setup_super (struct super_block * sb,
 580                               struct ext2_super_block * es,
 581                               int read_only)
 582 {
 583         int res = 0;
 584         struct ext2_sb_info *sbi = EXT2_SB(sb);
 585
 586         if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 587                 printk ("EXT2-fs warning: revision level too high, "
 588                         "forcing read-only mode\n");
 589                 res = MS_RDONLY;
 590         }
 591         if (read_only)
 592                 return res;
 593         if (!(sbi->s_mount_state & EXT2_VALID_FS))
 594                 printk ("EXT2-fs warning: mounting unchecked fs, "
 595                         "running e2fsck is recommended\n");
 596         else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 597                 printk ("EXT2-fs warning: mounting fs with errors, "
 598                         "running e2fsck is recommended\n");
 599         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 600                  le16_to_cpu(es->s_mnt_count) >=
 601                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 602                 printk ("EXT2-fs warning: maximal mount count reached, "
 603                         "running e2fsck is recommended\n");
 604         else if (le32_to_cpu(es->s_checkinterval) &&
 605                 (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 606                 printk ("EXT2-fs warning: checktime reached, "
 607                         "running e2fsck is recommended\n");
 608         if (!le16_to_cpu(es->s_max_mnt_count))
 609                 es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 610         le16_add_cpu(&es->s_mnt_count, 1);
 611         ext2_write_super(sb);
 612         if (test_opt (sb, DEBUG))
 613                 printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
 614                         "bpg=%lu, ipg=%lu, mo=%04lx]\n",
 615                         EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 616                         sbi->s_frag_size,
 617                         sbi->s_groups_count,
 618                         EXT2_BLOCKS_PER_GROUP(sb),
 619                         EXT2_INODES_PER_GROUP(sb),
 620                         sbi->s_mount_opt);
 621         return res;
 622 }
 623
 624 static int ext2_check_descriptors(struct super_block *sb)
 625 {
 626         int i;
 627         struct ext2_sb_info *sbi = EXT2_SB(sb);
 628
 629         ext2_debug ("Checking group descriptors");
 630
 631         for (i = 0; i < sbi->s_groups_count; i++) {
 632                 struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 633                 ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 634                 ext2_fsblk_t last_block;
 635
 636                 if (i == sbi->s_groups_count - 1)
 637                         last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 638                 else
 639                         last_block = first_block +
 640                                 (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 641
 642                 if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 643                     le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 644                 {
 645                         ext2_error (sb, "ext2_check_descriptors",
 646                                     "Block bitmap for group %d"
 647                                     " not in group (block %lu)!",
 648                                     i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 649                         return 0;
 650                 }
 651                 if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 652                     le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 653                 {
 654                         ext2_error (sb, "ext2_check_descriptors",
 655                                     "Inode bitmap for group %d"
 656                                     " not in group (block %lu)!",
 657                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 658                         return 0;
 659                 }
 660                 if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 661                     le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 662                     last_block)
 663                 {
 664                         ext2_error (sb, "ext2_check_descriptors",
 665                                     "Inode table for group %d"
 666                                     " not in group (block %lu)!",
 667                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 668                         return 0;
 669                 }
 670         }
 671         return 1;
 672 }
 673
 674 /*
 675  * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 676  * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 677  * We need to be 1 filesystem block less than the 2^32 sector limit.
 678  */
 679 static loff_t ext2_max_size(int bits)
 680 {
 681         loff_t res = EXT2_NDIR_BLOCKS;
 682         int meta_blocks;
 683         loff_t upper_limit;
 684
 685         /* This is calculated to be the largest file size for a
 686          * dense, file such that the total number of
 687          * sectors in the file, including data and all indirect blocks,
 688          * does not exceed 2^32 -1
 689          * __u32 i_blocks representing the total number of
 690          * 512 bytes blocks of the file
 691          */
 692         upper_limit = (1LL << 32) - 1;
 693
 694         /* total blocks in file system block size */
 695         upper_limit >>= (bits - 9);
 696
 697
 698         /* indirect blocks */
 699         meta_blocks = 1;
 700         /* double indirect blocks */
 701         meta_blocks += 1 + (1LL << (bits-2));
 702         /* tripple indirect blocks */
 703         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 704
 705         upper_limit -= meta_blocks;
 706         upper_limit <<= bits;
 707
 708         res += 1LL << (bits-2);
 709         res += 1LL << (2*(bits-2));
 710         res += 1LL << (3*(bits-2));
 711         res <<= bits;
 712         if (res > upper_limit)
 713                 res = upper_limit;
 714
 715         if (res > MAX_LFS_FILESIZE)
 716                 res = MAX_LFS_FILESIZE;
 717
 718         return res;
 719 }
 720
 721 static unsigned long descriptor_loc(struct super_block *sb,
 722                                     unsigned long logic_sb_block,
 723                                     int nr)
 724 {
 725         struct ext2_sb_info *sbi = EXT2_SB(sb);
 726         unsigned long bg, first_meta_bg;
 727         int has_super = 0;
 728
 729         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 730
 731         if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 732             nr < first_meta_bg)
 733                 return (logic_sb_block + nr + 1);
 734         bg = sbi->s_desc_per_block * nr;
 735         if (ext2_bg_has_super(sb, bg))
 736                 has_super = 1;
 737
 738         return ext2_group_first_block_no(sb, bg) + has_super;
 739 }
 740
 741 static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 742 {
 743         struct buffer_head * bh;
 744         struct ext2_sb_info * sbi;
 745         struct ext2_super_block * es;
 746         struct inode *root;
 747         unsigned long block;
 748         unsigned long sb_block = get_sb_block(&data);
 749         unsigned long logic_sb_block;
 750         unsigned long offset = 0;
 751         unsigned long def_mount_opts;
 752         long ret = -EINVAL;
 753         int blocksize = BLOCK_SIZE;
 754         int db_count;
 755         int i, j;
 756         __le32 features;
 757         int err;
 758
 759         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 760         if (!sbi)
 761                 return -ENOMEM;
 762
 763         sbi->s_blockgroup_lock =
 764                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 765         if (!sbi->s_blockgroup_lock) {
 766                 kfree(sbi);
 767                 return -ENOMEM;
 768         }
 769         sb->s_fs_info = sbi;
 770         sbi->s_sb_block = sb_block;
 771
 772         /*
 773          * See what the current blocksize for the device is, and
 774          * use that as the blocksize.  Otherwise (or if the blocksize
 775          * is smaller than the default) use the default.
 776          * This is important for devices that have a hardware
 777          * sectorsize that is larger than the default.
 778          */
 779         blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 780         if (!blocksize) {
 781                 printk ("EXT2-fs: unable to set blocksize\n");
 782                 goto failed_sbi;
 783         }
 784
 785         /*
 786          * If the superblock doesn't start on a hardware sector boundary,
 787          * calculate the offset.
 788          */
 789         if (blocksize != BLOCK_SIZE) {
 790                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 791                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 792         } else {
 793                 logic_sb_block = sb_block;
 794         }
 795
 796         if (!(bh = sb_bread(sb, logic_sb_block))) {
 797                 printk ("EXT2-fs: unable to read superblock\n");
 798                 goto failed_sbi;
 799         }
 800         /*
 801          * Note: s_es must be initialized as soon as possible because
 802          *       some ext2 macro-instructions depend on its value
 803          */
 804         es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 805         sbi->s_es = es;
 806         sb->s_magic = le16_to_cpu(es->s_magic);
 807
 808         if (sb->s_magic != EXT2_SUPER_MAGIC)
 809                 goto cantfind_ext2;
 810
 811         /* Set defaults before we parse the mount options */
 812         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 813         if (def_mount_opts & EXT2_DEFM_DEBUG)
 814                 set_opt(sbi->s_mount_opt, DEBUG);
 815         if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 816                 set_opt(sbi->s_mount_opt, GRPID);
 817         if (def_mount_opts & EXT2_DEFM_UID16)
 818                 set_opt(sbi->s_mount_opt, NO_UID32);
 819 #ifdef CONFIG_EXT2_FS_XATTR
 820         if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 821                 set_opt(sbi->s_mount_opt, XATTR_USER);
 822 #endif
 823 #ifdef CONFIG_EXT2_FS_POSIX_ACL
 824         if (def_mount_opts & EXT2_DEFM_ACL)
 825                 set_opt(sbi->s_mount_opt, POSIX_ACL);
 826 #endif
 827
 828         if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 829                 set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 830         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 831                 set_opt(sbi->s_mount_opt, ERRORS_CONT);
 832         else
 833                 set_opt(sbi->s_mount_opt, ERRORS_RO);
 834
 835         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 836         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 837
 838         set_opt(sbi->s_mount_opt, RESERVATION);
 839
 840         if (!parse_options ((char *) data, sbi))
 841                 goto failed_mount;
 842
 843         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 844                 ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 845                  MS_POSIXACL : 0);
 846
 847         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 848                                     EXT2_MOUNT_XIP if not */
 849
 850         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 851             (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 852              EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 853              EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 854                 printk("EXT2-fs warning: feature flags set on rev 0 fs, "
 855                        "running e2fsck is recommended\n");
 856         /*
 857          * Check feature flags regardless of the revision level, since we
 858          * previously didn't change the revision level when setting the flags,
 859          * so there is a chance incompat flags are set on a rev 0 filesystem.
 860          */
 861         features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 862         if (features) {
 863                 printk("EXT2-fs: %s: couldn't mount because of "
 864                        "unsupported optional features (%x).\n",
 865                        sb->s_id, le32_to_cpu(features));
 866                 goto failed_mount;
 867         }
 868         if (!(sb->s_flags & MS_RDONLY) &&
 869             (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 870                 printk("EXT2-fs: %s: couldn't mount RDWR because of "
 871                        "unsupported optional features (%x).\n",
 872                        sb->s_id, le32_to_cpu(features));
 873                 goto failed_mount;
 874         }
 875
 876         blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 877
 878         if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
 879                 if (!silent)
 880                         printk("XIP: Unsupported blocksize\n");
 881                 goto failed_mount;
 882         }
 883
 884         /* If the blocksize doesn't match, re-read the thing.. */
 885         if (sb->s_blocksize != blocksize) {
 886                 brelse(bh);
 887
 888                 if (!sb_set_blocksize(sb, blocksize)) {
 889                         printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
 890                         goto failed_sbi;
 891                 }
 892
 893                 logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 894                 offset = (sb_block*BLOCK_SIZE) % blocksize;
 895                 bh = sb_bread(sb, logic_sb_block);
 896                 if(!bh) {
 897                         printk("EXT2-fs: Couldn't read superblock on "
 898                                "2nd try.\n");
 899                         goto failed_sbi;
 900                 }
 901                 es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 902                 sbi->s_es = es;
 903                 if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 904                         printk ("EXT2-fs: Magic mismatch, very weird !\n");
 905                         goto failed_mount;
 906                 }
 907         }
 908
 909         sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 910
 911         if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 912                 sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 913                 sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 914         } else {
 915                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 916                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 917                 if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 918                     !is_power_of_2(sbi->s_inode_size) ||
 919                     (sbi->s_inode_size > blocksize)) {
 920                         printk ("EXT2-fs: unsupported inode size: %d\n",
 921                                 sbi->s_inode_size);
 922                         goto failed_mount;
 923                 }
 924         }
 925
 926         sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 927                                    le32_to_cpu(es->s_log_frag_size);
 928         if (sbi->s_frag_size == 0)
 929                 goto cantfind_ext2;
 930         sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 931
 932         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 933         sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 934         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 935
 936         if (EXT2_INODE_SIZE(sb) == 0)
 937                 goto cantfind_ext2;
 938         sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 939         if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 940                 goto cantfind_ext2;
 941         sbi->s_itb_per_group = sbi->s_inodes_per_group /
 942                                         sbi->s_inodes_per_block;
 943         sbi->s_desc_per_block = sb->s_blocksize /
 944                                         sizeof (struct ext2_group_desc);
 945         sbi->s_sbh = bh;
 946         sbi->s_mount_state = le16_to_cpu(es->s_state);
 947         sbi->s_addr_per_block_bits =
 948                 ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 949         sbi->s_desc_per_block_bits =
 950                 ilog2 (EXT2_DESC_PER_BLOCK(sb));
 951
 952         if (sb->s_magic != EXT2_SUPER_MAGIC)
 953                 goto cantfind_ext2;
 954
 955         if (sb->s_blocksize != bh->b_size) {
 956                 if (!silent)
 957                         printk ("VFS: Unsupported blocksize on dev "
 958                                 "%s.\n", sb->s_id);
 959                 goto failed_mount;
 960         }
 961
 962         if (sb->s_blocksize != sbi->s_frag_size) {
 963                 printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
 964                         sbi->s_frag_size, sb->s_blocksize);
 965                 goto failed_mount;
 966         }
 967
 968         if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 969                 printk ("EXT2-fs: #blocks per group too big: %lu\n",
 970                         sbi->s_blocks_per_group);
 971                 goto failed_mount;
 972         }
 973         if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 974                 printk ("EXT2-fs: #fragments per group too big: %lu\n",
 975                         sbi->s_frags_per_group);
 976                 goto failed_mount;
 977         }
 978         if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 979                 printk ("EXT2-fs: #inodes per group too big: %lu\n",
 980                         sbi->s_inodes_per_group);
 981                 goto failed_mount;
 982         }
 983
 984         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 985                 goto cantfind_ext2;
 986         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
 987                                 le32_to_cpu(es->s_first_data_block) - 1)
 988                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
 989         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 990                    EXT2_DESC_PER_BLOCK(sb);
 991         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
 992         if (sbi->s_group_desc == NULL) {
 993                 printk ("EXT2-fs: not enough memory\n");
 994                 goto failed_mount;
 995         }
 996         bgl_lock_init(sbi->s_blockgroup_lock);
 997         sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
 998         if (!sbi->s_debts) {
 999                 printk ("EXT2-fs: not enough memory\n");
1000                 goto failed_mount_group_desc;
1001         }
1002         for (i = 0; i < db_count; i++) {
1003                 block = descriptor_loc(sb, logic_sb_block, i);
1004                 sbi->s_group_desc[i] = sb_bread(sb, block);
1005                 if (!sbi->s_group_desc[i]) {
1006                         for (j = 0; j < i; j++)
1007                                 brelse (sbi->s_group_desc[j]);
1008                         printk ("EXT2-fs: unable to read group descriptors\n");
1009                         goto failed_mount_group_desc;
1010                 }
1011         }
1012         if (!ext2_check_descriptors (sb)) {
1013                 printk ("EXT2-fs: group descriptors corrupted!\n");
1014                 goto failed_mount2;
1015         }
1016         sbi->s_gdb_count = db_count;
1017         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1018         spin_lock_init(&sbi->s_next_gen_lock);
1019
1020         /* per fileystem reservation list head & lock */
1021         spin_lock_init(&sbi->s_rsv_window_lock);
1022         sbi->s_rsv_window_root = RB_ROOT;
1023         /*
1024          * Add a single, static dummy reservation to the start of the
1025          * reservation window list --- it gives us a placeholder for
1026          * append-at-start-of-list which makes the allocation logic
1027          * _much_ simpler.
1028          */
1029         sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1030         sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1031         sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1032         sbi->s_rsv_window_head.rsv_goal_size = 0;
1033         ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1034
1035         err = percpu_counter_init(&sbi->s_freeblocks_counter,
1036                                 ext2_count_free_blocks(sb));
1037         if (!err) {
1038                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
1039                                 ext2_count_free_inodes(sb));
1040         }
1041         if (!err) {
1042                 err = percpu_counter_init(&sbi->s_dirs_counter,
1043                                 ext2_count_dirs(sb));
1044         }
1045         if (err) {
1046                 printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1047                 goto failed_mount3;
1048         }
1049         /*
1050          * set up enough so that it can read an inode
1051          */
1052         sb->s_op = &ext2_sops;
1053         sb->s_export_op = &ext2_export_ops;
1054         sb->s_xattr = ext2_xattr_handlers;
1055         root = ext2_iget(sb, EXT2_ROOT_INO);
1056         if (IS_ERR(root)) {
1057                 ret = PTR_ERR(root);
1058                 goto failed_mount3;
1059         }
1060         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1061                 iput(root);
1062                 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1063                 goto failed_mount3;
1064         }
1065
1066         sb->s_root = d_alloc_root(root);
1067         if (!sb->s_root) {
1068                 iput(root);
1069                 printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1070                 ret = -ENOMEM;
1071                 goto failed_mount3;
1072         }
1073         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1074                 ext2_warning(sb, __func__,
1075                         "mounting ext3 filesystem as ext2");
1076         ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1077         return 0;
1078
1079 cantfind_ext2:
1080         if (!silent)
1081                 printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1082                        sb->s_id);
1083         goto failed_mount;
1084 failed_mount3:
1085         percpu_counter_destroy(&sbi->s_freeblocks_counter);
1086         percpu_counter_destroy(&sbi->s_freeinodes_counter);
1087         percpu_counter_destroy(&sbi->s_dirs_counter);
1088 failed_mount2:
1089         for (i = 0; i < db_count; i++)
1090                 brelse(sbi->s_group_desc[i]);
1091 failed_mount_group_desc:
1092         kfree(sbi->s_group_desc);
1093         kfree(sbi->s_debts);
1094 failed_mount:
1095         brelse(bh);
1096 failed_sbi:
1097         sb->s_fs_info = NULL;
1098         kfree(sbi);
1099         return ret;
1100 }
1101
1102 static void ext2_commit_super (struct super_block * sb,
1103                                struct ext2_super_block * es)
1104 {
1105         es->s_wtime = cpu_to_le32(get_seconds());
1106         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1107         sb->s_dirt = 0;
1108 }
1109
1110 static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1111 {
1112         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1113         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1114         es->s_wtime = cpu_to_le32(get_seconds());
1115         mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1116         sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1117         sb->s_dirt = 0;
1118 }
1119
1120 /*
1121  * In the second extended file system, it is not necessary to
1122  * write the super block since we use a mapping of the
1123  * disk super block in a buffer.
1124  *
1125  * However, this function is still used to set the fs valid
1126  * flags to 0.  We need to set this flag to 0 since the fs
1127  * may have been checked while mounted and e2fsck may have
1128  * set s_state to EXT2_VALID_FS after some corrections.
1129  */
1130
1131 void ext2_write_super (struct super_block * sb)
1132 {
1133         struct ext2_super_block * es;
1134         lock_kernel();
1135         if (!(sb->s_flags & MS_RDONLY)) {
1136                 es = EXT2_SB(sb)->s_es;
1137
1138                 if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1139                         ext2_debug ("setting valid to 0\n");
1140                         es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1141                         es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1142                         es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1143                         es->s_mtime = cpu_to_le32(get_seconds());
1144                         ext2_sync_super(sb, es);
1145                 } else
1146                         ext2_commit_super (sb, es);
1147         }
1148         sb->s_dirt = 0;
1149         unlock_kernel();
1150 }
1151
1152 static int ext2_remount (struct super_block * sb, int * flags, char * data)
1153 {
1154         struct ext2_sb_info * sbi = EXT2_SB(sb);
1155         struct ext2_super_block * es;
1156         unsigned long old_mount_opt = sbi->s_mount_opt;
1157         struct ext2_mount_options old_opts;
1158         unsigned long old_sb_flags;
1159         int err;
1160
1161         /* Store the old options */
1162         old_sb_flags = sb->s_flags;
1163         old_opts.s_mount_opt = sbi->s_mount_opt;
1164         old_opts.s_resuid = sbi->s_resuid;
1165         old_opts.s_resgid = sbi->s_resgid;
1166
1167         /*
1168          * Allow the "check" option to be passed as a remount option.
1169          */
1170         if (!parse_options (data, sbi)) {
1171                 err = -EINVAL;
1172                 goto restore_opts;
1173         }
1174
1175         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1176                 ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1177
1178         ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1179                                     EXT2_MOUNT_XIP if not */
1180
1181         if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1182                 printk("XIP: Unsupported blocksize\n");
1183                 err = -EINVAL;
1184                 goto restore_opts;
1185         }
1186
1187         es = sbi->s_es;
1188         if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1189             (old_mount_opt & EXT2_MOUNT_XIP)) &&
1190             invalidate_inodes(sb)) {
1191                 ext2_warning(sb, __func__, "refusing change of xip flag "
1192                              "with busy inodes while remounting");
1193                 sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1194                 sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1195         }
1196         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1197                 return 0;
1198         if (*flags & MS_RDONLY) {
1199                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1200                     !(sbi->s_mount_state & EXT2_VALID_FS))
1201                         return 0;
1202                 /*
1203                  * OK, we are remounting a valid rw partition rdonly, so set
1204                  * the rdonly flag and then mark the partition as valid again.
1205                  */
1206                 es->s_state = cpu_to_le16(sbi->s_mount_state);
1207                 es->s_mtime = cpu_to_le32(get_seconds());
1208         } else {
1209                 __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1210                                                ~EXT2_FEATURE_RO_COMPAT_SUPP);
1211                 if (ret) {
1212                         printk("EXT2-fs: %s: couldn't remount RDWR because of "
1213                                "unsupported optional features (%x).\n",
1214                                sb->s_id, le32_to_cpu(ret));
1215                         err = -EROFS;
1216                         goto restore_opts;
1217                 }
1218                 /*
1219                  * Mounting a RDONLY partition read-write, so reread and
1220                  * store the current valid flag.  (It may have been changed
1221                  * by e2fsck since we originally mounted the partition.)
1222                  */
1223                 sbi->s_mount_state = le16_to_cpu(es->s_state);
1224                 if (!ext2_setup_super (sb, es, 0))
1225                         sb->s_flags &= ~MS_RDONLY;
1226         }
1227         ext2_sync_super(sb, es);
1228         return 0;
1229 restore_opts:
1230         sbi->s_mount_opt = old_opts.s_mount_opt;
1231         sbi->s_resuid = old_opts.s_resuid;
1232         sbi->s_resgid = old_opts.s_resgid;
1233         sb->s_flags = old_sb_flags;
1234         return err;
1235 }
1236
1237 static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1238 {
1239         struct super_block *sb = dentry->d_sb;
1240         struct ext2_sb_info *sbi = EXT2_SB(sb);
1241         struct ext2_super_block *es = sbi->s_es;
1242         u64 fsid;
1243
1244         if (test_opt (sb, MINIX_DF))
1245                 sbi->s_overhead_last = 0;
1246         else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1247                 unsigned long i, overhead = 0;
1248                 smp_rmb();
1249
1250                 /*
1251                  * Compute the overhead (FS structures). This is constant
1252                  * for a given filesystem unless the number of block groups
1253                  * changes so we cache the previous value until it does.
1254                  */
1255
1256                 /*
1257                  * All of the blocks before first_data_block are
1258                  * overhead
1259                  */
1260                 overhead = le32_to_cpu(es->s_first_data_block);
1261
1262                 /*
1263                  * Add the overhead attributed to the superblock and
1264                  * block group descriptors.  If the sparse superblocks
1265                  * feature is turned on, then not all groups have this.
1266                  */
1267                 for (i = 0; i < sbi->s_groups_count; i++)
1268                         overhead += ext2_bg_has_super(sb, i) +
1269                                 ext2_bg_num_gdb(sb, i);
1270
1271                 /*
1272                  * Every block group has an inode bitmap, a block
1273                  * bitmap, and an inode table.
1274                  */
1275                 overhead += (sbi->s_groups_count *
1276                              (2 + sbi->s_itb_per_group));
1277                 sbi->s_overhead_last = overhead;
1278                 smp_wmb();
1279                 sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1280         }
1281
1282         buf->f_type = EXT2_SUPER_MAGIC;
1283         buf->f_bsize = sb->s_blocksize;
1284         buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1285         buf->f_bfree = ext2_count_free_blocks(sb);
1286         es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1287         buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1288         if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1289                 buf->f_bavail = 0;
1290         buf->f_files = le32_to_cpu(es->s_inodes_count);
1291         buf->f_ffree = ext2_count_free_inodes(sb);
1292         es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1293         buf->f_namelen = EXT2_NAME_LEN;
1294         fsid = le64_to_cpup((void *)es->s_uuid) ^
1295                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1296         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1297         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1298         return 0;
1299 }
1300
1301 static int ext2_get_sb(struct file_system_type *fs_type,
1302         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1303 {
1304         return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1305 }
1306
1307 #ifdef CONFIG_QUOTA
1308
1309 /* Read data from quotafile - avoid pagecache and such because we cannot afford
1310  * acquiring the locks... As quota files are never truncated and quota code
1311  * itself serializes the operations (and noone else should touch the files)
1312  * we don't have to be afraid of races */
1313 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1314                                size_t len, loff_t off)
1315 {
1316         struct inode *inode = sb_dqopt(sb)->files[type];
1317         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1318         int err = 0;
1319         int offset = off & (sb->s_blocksize - 1);
1320         int tocopy;
1321         size_t toread;
1322         struct buffer_head tmp_bh;
1323         struct buffer_head *bh;
1324         loff_t i_size = i_size_read(inode);
1325
1326         if (off > i_size)
1327                 return 0;
1328         if (off+len > i_size)
1329                 len = i_size-off;
1330         toread = len;
1331         while (toread > 0) {
1332                 tocopy = sb->s_blocksize - offset < toread ?
1333                                 sb->s_blocksize - offset : toread;
1334
1335                 tmp_bh.b_state = 0;
1336                 err = ext2_get_block(inode, blk, &tmp_bh, 0);
1337                 if (err < 0)
1338                         return err;
1339                 if (!buffer_mapped(&tmp_bh))    /* A hole? */
1340                         memset(data, 0, tocopy);
1341                 else {
1342                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1343                         if (!bh)
1344                                 return -EIO;
1345                         memcpy(data, bh->b_data+offset, tocopy);
1346                         brelse(bh);
1347                 }
1348                 offset = 0;
1349                 toread -= tocopy;
1350                 data += tocopy;
1351                 blk++;
1352         }
1353         return len;
1354 }
1355
1356 /* Write to quotafile */
1357 static ssize_t ext2_quota_write(struct super_block *sb, int type,
1358                                 const char *data, size_t len, loff_t off)
1359 {
1360         struct inode *inode = sb_dqopt(sb)->files[type];
1361         sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1362         int err = 0;
1363         int offset = off & (sb->s_blocksize - 1);
1364         int tocopy;
1365         size_t towrite = len;
1366         struct buffer_head tmp_bh;
1367         struct buffer_head *bh;
1368
1369         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1370         while (towrite > 0) {
1371                 tocopy = sb->s_blocksize - offset < towrite ?
1372                                 sb->s_blocksize - offset : towrite;
1373
1374                 tmp_bh.b_state = 0;
1375                 err = ext2_get_block(inode, blk, &tmp_bh, 1);
1376                 if (err < 0)
1377                         goto out;
1378                 if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1379                         bh = sb_bread(sb, tmp_bh.b_blocknr);
1380                 else
1381                         bh = sb_getblk(sb, tmp_bh.b_blocknr);
1382                 if (!bh) {
1383                         err = -EIO;
1384                         goto out;
1385                 }
1386                 lock_buffer(bh);
1387                 memcpy(bh->b_data+offset, data, tocopy);
1388                 flush_dcache_page(bh->b_page);
1389                 set_buffer_uptodate(bh);
1390                 mark_buffer_dirty(bh);
1391                 unlock_buffer(bh);
1392                 brelse(bh);
1393                 offset = 0;
1394                 towrite -= tocopy;
1395                 data += tocopy;
1396                 blk++;
1397         }
1398 out:
1399         if (len == towrite)
1400                 return err;
1401         if (inode->i_size < off+len-towrite)
1402                 i_size_write(inode, off+len-towrite);
1403         inode->i_version++;
1404         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1405         mark_inode_dirty(inode);
1406         mutex_unlock(&inode->i_mutex);
1407         return len - towrite;
1408 }
1409
1410 #endif
1411
1412 static struct file_system_type ext2_fs_type = {
1413         .owner          = THIS_MODULE,
1414         .name           = "ext2",
1415         .get_sb         = ext2_get_sb,
1416         .kill_sb        = kill_block_super,
1417         .fs_flags       = FS_REQUIRES_DEV,
1418 };
1419
1420 static int __init init_ext2_fs(void)
1421 {
1422         int err = init_ext2_xattr();
1423         if (err)
1424                 return err;
1425         err = init_inodecache();
1426         if (err)
1427                 goto out1;
1428         err = register_filesystem(&ext2_fs_type);
1429         if (err)
1430                 goto out;
1431         return 0;
1432 out:
1433         destroy_inodecache();
1434 out1:
1435         exit_ext2_xattr();
1436         return err;
1437 }
1438
1439 static void __exit exit_ext2_fs(void)
1440 {
1441         unregister_filesystem(&ext2_fs_type);
1442         destroy_inodecache();
1443         exit_ext2_xattr();
1444 }
1445
1446 module_init(init_ext2_fs)
1447 module_exit(exit_ext2_fs)