linux/fs/ext2/super.c
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   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
  41static void ext2_sync_super(struct super_block *sb,
  42                            struct ext2_super_block *es);
  43static int ext2_remount (struct super_block * sb, int * flags, char * data);
  44static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  45
  46void 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
  73void 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
  86void 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
 111static 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
 141static struct kmem_cache * ext2_inode_cachep;
 142
 143static 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
 158static void ext2_destroy_inode(struct inode *inode)
 159{
 160        kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 161}
 162
 163static void init_once(void *foo)
 164{
 165        struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 166
 167        rwlock_init(&ei->i_meta_lock);
 168#ifdef CONFIG_EXT2_FS_XATTR
 169        init_rwsem(&ei->xattr_sem);
 170#endif
 171        mutex_init(&ei->truncate_mutex);
 172        inode_init_once(&ei->vfs_inode);
 173}
 174
 175static int init_inodecache(void)
 176{
 177        ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 178                                             sizeof(struct ext2_inode_info),
 179                                             0, (SLAB_RECLAIM_ACCOUNT|
 180                                                SLAB_MEM_SPREAD),
 181                                             init_once);
 182        if (ext2_inode_cachep == NULL)
 183                return -ENOMEM;
 184        return 0;
 185}
 186
 187static void destroy_inodecache(void)
 188{
 189        kmem_cache_destroy(ext2_inode_cachep);
 190}
 191
 192static void ext2_clear_inode(struct inode *inode)
 193{
 194        struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
 195#ifdef CONFIG_EXT2_FS_POSIX_ACL
 196        struct ext2_inode_info *ei = EXT2_I(inode);
 197
 198        if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
 199                posix_acl_release(ei->i_acl);
 200                ei->i_acl = EXT2_ACL_NOT_CACHED;
 201        }
 202        if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
 203                posix_acl_release(ei->i_default_acl);
 204                ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 205        }
 206#endif
 207        ext2_discard_reservation(inode);
 208        EXT2_I(inode)->i_block_alloc_info = NULL;
 209        if (unlikely(rsv))
 210                kfree(rsv);
 211}
 212
 213static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
 214{
 215        struct super_block *sb = vfs->mnt_sb;
 216        struct ext2_sb_info *sbi = EXT2_SB(sb);
 217        struct ext2_super_block *es = sbi->s_es;
 218        unsigned long def_mount_opts;
 219
 220        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 221
 222        if (sbi->s_sb_block != 1)
 223                seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 224        if (test_opt(sb, MINIX_DF))
 225                seq_puts(seq, ",minixdf");
 226        if (test_opt(sb, GRPID))
 227                seq_puts(seq, ",grpid");
 228        if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 229                seq_puts(seq, ",nogrpid");
 230        if (sbi->s_resuid != EXT2_DEF_RESUID ||
 231            le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 232                seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 233        }
 234        if (sbi->s_resgid != EXT2_DEF_RESGID ||
 235            le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 236                seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 237        }
 238        if (test_opt(sb, ERRORS_RO)) {
 239                int def_errors = le16_to_cpu(es->s_errors);
 240
 241                if (def_errors == EXT2_ERRORS_PANIC ||
 242                    def_errors == EXT2_ERRORS_CONTINUE) {
 243                        seq_puts(seq, ",errors=remount-ro");
 244                }
 245        }
 246        if (test_opt(sb, ERRORS_CONT))
 247                seq_puts(seq, ",errors=continue");
 248        if (test_opt(sb, ERRORS_PANIC))
 249                seq_puts(seq, ",errors=panic");
 250        if (test_opt(sb, NO_UID32))
 251                seq_puts(seq, ",nouid32");
 252        if (test_opt(sb, DEBUG))
 253                seq_puts(seq, ",debug");
 254        if (test_opt(sb, OLDALLOC))
 255                seq_puts(seq, ",oldalloc");
 256
 257#ifdef CONFIG_EXT2_FS_XATTR
 258        if (test_opt(sb, XATTR_USER))
 259                seq_puts(seq, ",user_xattr");
 260        if (!test_opt(sb, XATTR_USER) &&
 261            (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 262                seq_puts(seq, ",nouser_xattr");
 263        }
 264#endif
 265
 266#ifdef CONFIG_EXT2_FS_POSIX_ACL
 267        if (test_opt(sb, POSIX_ACL))
 268                seq_puts(seq, ",acl");
 269        if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 270                seq_puts(seq, ",noacl");
 271#endif
 272
 273        if (test_opt(sb, NOBH))
 274                seq_puts(seq, ",nobh");
 275
 276#if defined(CONFIG_QUOTA)
 277        if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 278                seq_puts(seq, ",usrquota");
 279
 280        if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 281                seq_puts(seq, ",grpquota");
 282#endif
 283
 284#if defined(CONFIG_EXT2_FS_XIP)
 285        if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 286                seq_puts(seq, ",xip");
 287#endif
 288
 289        if (!test_opt(sb, RESERVATION))
 290                seq_puts(seq, ",noreservation");
 291
 292        return 0;
 293}
 294
 295#ifdef CONFIG_QUOTA
 296static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 297static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 298#endif
 299
 300static const struct super_operations ext2_sops = {
 301        .alloc_inode    = ext2_alloc_inode,
 302        .destroy_inode  = ext2_destroy_inode,
 303        .write_inode    = ext2_write_inode,
 304        .delete_inode   = ext2_delete_inode,
 305        .put_super      = ext2_put_super,
 306        .write_super    = ext2_write_super,
 307        .statfs         = ext2_statfs,
 308        .remount_fs     = ext2_remount,
 309        .clear_inode    = ext2_clear_inode,
 310        .show_options   = ext2_show_options,
 311#ifdef CONFIG_QUOTA
 312        .quota_read     = ext2_quota_read,
 313        .quota_write    = ext2_quota_write,
 314#endif
 315};
 316
 317static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 318                u64 ino, u32 generation)
 319{
 320        struct inode *inode;
 321
 322        if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 323                return ERR_PTR(-ESTALE);
 324        if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 325                return ERR_PTR(-ESTALE);
 326
 327        /* iget isn't really right if the inode is currently unallocated!!
 328         * ext2_read_inode currently does appropriate checks, but
 329         * it might be "neater" to call ext2_get_inode first and check
 330         * if the inode is valid.....
 331         */
 332        inode = ext2_iget(sb, ino);
 333        if (IS_ERR(inode))
 334                return ERR_CAST(inode);
 335        if (generation && inode->i_generation != generation) {
 336                /* we didn't find the right inode.. */
 337                iput(inode);
 338                return ERR_PTR(-ESTALE);
 339        }
 340        return inode;
 341}
 342
 343static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 344                int fh_len, int fh_type)
 345{
 346        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 347                                    ext2_nfs_get_inode);
 348}
 349
 350static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 351                int fh_len, int fh_type)
 352{
 353        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 354                                    ext2_nfs_get_inode);
 355}
 356
 357/* Yes, most of these are left as NULL!!
 358 * A NULL value implies the default, which works with ext2-like file
 359 * systems, but can be improved upon.
 360 * Currently only get_parent is required.
 361 */
 362static const struct export_operations ext2_export_ops = {
 363        .fh_to_dentry = ext2_fh_to_dentry,
 364        .fh_to_parent = ext2_fh_to_parent,
 365        .get_parent = ext2_get_parent,
 366};
 367
 368static unsigned long get_sb_block(void **data)
 369{
 370        unsigned long   sb_block;
 371        char            *options = (char *) *data;
 372
 373        if (!options || strncmp(options, "sb=", 3) != 0)
 374                return 1;       /* Default location */
 375        options += 3;
 376        sb_block = simple_strtoul(options, &options, 0);
 377        if (*options && *options != ',') {
 378                printk("EXT2-fs: Invalid sb specification: %s\n",
 379                       (char *) *data);
 380                return 1;
 381        }
 382        if (*options == ',')
 383                options++;
 384        *data = (void *) options;
 385        return sb_block;
 386}
 387
 388enum {
 389        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 390        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 391        Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 392        Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 393        Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 394        Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 395};
 396
 397static const match_table_t tokens = {
 398        {Opt_bsd_df, "bsddf"},
 399        {Opt_minix_df, "minixdf"},
 400        {Opt_grpid, "grpid"},
 401        {Opt_grpid, "bsdgroups"},
 402        {Opt_nogrpid, "nogrpid"},
 403        {Opt_nogrpid, "sysvgroups"},
 404        {Opt_resgid, "resgid=%u"},
 405        {Opt_resuid, "resuid=%u"},
 406        {Opt_sb, "sb=%u"},
 407        {Opt_err_cont, "errors=continue"},
 408        {Opt_err_panic, "errors=panic"},
 409        {Opt_err_ro, "errors=remount-ro"},
 410        {Opt_nouid32, "nouid32"},
 411        {Opt_nocheck, "check=none"},
 412        {Opt_nocheck, "nocheck"},
 413        {Opt_debug, "debug"},
 414        {Opt_oldalloc, "oldalloc"},
 415        {Opt_orlov, "orlov"},
 416        {Opt_nobh, "nobh"},
 417        {Opt_user_xattr, "user_xattr"},
 418        {Opt_nouser_xattr, "nouser_xattr"},
 419        {Opt_acl, "acl"},
 420        {Opt_noacl, "noacl"},
 421        {Opt_xip, "xip"},
 422        {Opt_grpquota, "grpquota"},
 423        {Opt_ignore, "noquota"},
 424        {Opt_quota, "quota"},
 425        {Opt_usrquota, "usrquota"},
 426        {Opt_reservation, "reservation"},
 427        {Opt_noreservation, "noreservation"},
 428        {Opt_err, NULL}
 429};
 430
 431static int parse_options (char * options,
 432                          struct ext2_sb_info *sbi)
 433{
 434        char * p;
 435        substring_t args[MAX_OPT_ARGS];
 436        int option;
 437
 438        if (!options)
 439                return 1;
 440
 441        while ((p = strsep (&options, ",")) != NULL) {
 442                int token;
 443                if (!*p)
 444                        continue;
 445
 446                token = match_token(p, tokens, args);
 447                switch (token) {
 448                case Opt_bsd_df:
 449                        clear_opt (sbi->s_mount_opt, MINIX_DF);
 450                        break;
 451                case Opt_minix_df:
 452                        set_opt (sbi->s_mount_opt, MINIX_DF);
 453                        break;
 454                case Opt_grpid:
 455                        set_opt (sbi->s_mount_opt, GRPID);
 456                        break;
 457                case Opt_nogrpid:
 458                        clear_opt (sbi->s_mount_opt, GRPID);
 459                        break;
 460                case Opt_resuid:
 461                        if (match_int(&args[0], &option))
 462                                return 0;
 463                        sbi->s_resuid = option;
 464                        break;
 465                case Opt_resgid:
 466                        if (match_int(&args[0], &option))
 467                                return 0;
 468                        sbi->s_resgid = option;
 469                        break;
 470                case Opt_sb:
 471                        /* handled by get_sb_block() instead of here */
 472                        /* *sb_block = match_int(&args[0]); */
 473                        break;
 474                case Opt_err_panic:
 475                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 476                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 477                        set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 478                        break;
 479                case Opt_err_ro:
 480                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 481                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 482                        set_opt (sbi->s_mount_opt, ERRORS_RO);
 483                        break;
 484                case Opt_err_cont:
 485                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 486                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 487                        set_opt (sbi->s_mount_opt, ERRORS_CONT);
 488                        break;
 489                case Opt_nouid32:
 490                        set_opt (sbi->s_mount_opt, NO_UID32);
 491                        break;
 492                case Opt_nocheck:
 493                        clear_opt (sbi->s_mount_opt, CHECK);
 494                        break;
 495                case Opt_debug:
 496                        set_opt (sbi->s_mount_opt, DEBUG);
 497                        break;
 498                case Opt_oldalloc:
 499                        set_opt (sbi->s_mount_opt, OLDALLOC);
 500                        break;
 501                case Opt_orlov:
 502                        clear_opt (sbi->s_mount_opt, OLDALLOC);
 503                        break;
 504                case Opt_nobh:
 505                        set_opt (sbi->s_mount_opt, NOBH);
 506                        break;
 507#ifdef CONFIG_EXT2_FS_XATTR
 508                case Opt_user_xattr:
 509                        set_opt (sbi->s_mount_opt, XATTR_USER);
 510                        break;
 511                case Opt_nouser_xattr:
 512                        clear_opt (sbi->s_mount_opt, XATTR_USER);
 513                        break;
 514#else
 515                case Opt_user_xattr:
 516                case Opt_nouser_xattr:
 517                        printk("EXT2 (no)user_xattr options not supported\n");
 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                        printk("EXT2 (no)acl options not supported\n");
 531                        break;
 532#endif
 533                case Opt_xip:
 534#ifdef CONFIG_EXT2_FS_XIP
 535                        set_opt (sbi->s_mount_opt, XIP);
 536#else
 537                        printk("EXT2 xip option not supported\n");
 538#endif
 539                        break;
 540
 541#if defined(CONFIG_QUOTA)
 542                case Opt_quota:
 543                case Opt_usrquota:
 544                        set_opt(sbi->s_mount_opt, USRQUOTA);
 545                        break;
 546
 547                case Opt_grpquota:
 548                        set_opt(sbi->s_mount_opt, GRPQUOTA);
 549                        break;
 550#else
 551                case Opt_quota:
 552                case Opt_usrquota:
 553                case Opt_grpquota:
 554                        printk(KERN_ERR
 555                                "EXT2-fs: quota operations not supported.\n");
 556
 557                        break;
 558#endif
 559
 560                case Opt_reservation:
 561                        set_opt(sbi->s_mount_opt, RESERVATION);
 562                        printk("reservations ON\n");
 563                        break;
 564                case Opt_noreservation:
 565                        clear_opt(sbi->s_mount_opt, RESERVATION);
 566                        printk("reservations OFF\n");
 567                        break;
 568                case Opt_ignore:
 569                        break;
 570                default:
 571                        return 0;
 572                }
 573        }
 574        return 1;
 575}
 576
 577static 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                printk ("EXT2-fs warning: revision level too high, "
 586                        "forcing read-only mode\n");
 587                res = MS_RDONLY;
 588        }
 589        if (read_only)
 590                return res;
 591        if (!(sbi->s_mount_state & EXT2_VALID_FS))
 592                printk ("EXT2-fs warning: mounting unchecked fs, "
 593                        "running e2fsck is recommended\n");
 594        else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 595                printk ("EXT2-fs warning: mounting fs with errors, "
 596                        "running e2fsck is recommended\n");
 597        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 598                 le16_to_cpu(es->s_mnt_count) >=
 599                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 600                printk ("EXT2-fs warning: maximal mount count reached, "
 601                        "running e2fsck is recommended\n");
 602        else if (le32_to_cpu(es->s_checkinterval) &&
 603                (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 604                printk ("EXT2-fs warning: checktime reached, "
 605                        "running e2fsck is recommended\n");
 606        if (!le16_to_cpu(es->s_max_mnt_count))
 607                es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 608        le16_add_cpu(&es->s_mnt_count, 1);
 609        ext2_write_super(sb);
 610        if (test_opt (sb, DEBUG))
 611                printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
 612                        "bpg=%lu, ipg=%lu, mo=%04lx]\n",
 613                        EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 614                        sbi->s_frag_size,
 615                        sbi->s_groups_count,
 616                        EXT2_BLOCKS_PER_GROUP(sb),
 617                        EXT2_INODES_PER_GROUP(sb),
 618                        sbi->s_mount_opt);
 619        return res;
 620}
 621
 622static int ext2_check_descriptors(struct super_block *sb)
 623{
 624        int i;
 625        struct ext2_sb_info *sbi = EXT2_SB(sb);
 626
 627        ext2_debug ("Checking group descriptors");
 628
 629        for (i = 0; i < sbi->s_groups_count; i++) {
 630                struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 631                ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 632                ext2_fsblk_t last_block;
 633
 634                if (i == sbi->s_groups_count - 1)
 635                        last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 636                else
 637                        last_block = first_block +
 638                                (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 639
 640                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 641                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 642                {
 643                        ext2_error (sb, "ext2_check_descriptors",
 644                                    "Block bitmap for group %d"
 645                                    " not in group (block %lu)!",
 646                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 647                        return 0;
 648                }
 649                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 650                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 651                {
 652                        ext2_error (sb, "ext2_check_descriptors",
 653                                    "Inode bitmap for group %d"
 654                                    " not in group (block %lu)!",
 655                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 656                        return 0;
 657                }
 658                if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 659                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 660                    last_block)
 661                {
 662                        ext2_error (sb, "ext2_check_descriptors",
 663                                    "Inode table for group %d"
 664                                    " not in group (block %lu)!",
 665                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 666                        return 0;
 667                }
 668        }
 669        return 1;
 670}
 671
 672/*
 673 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 674 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 675 * We need to be 1 filesystem block less than the 2^32 sector limit.
 676 */
 677static loff_t ext2_max_size(int bits)
 678{
 679        loff_t res = EXT2_NDIR_BLOCKS;
 680        int meta_blocks;
 681        loff_t upper_limit;
 682
 683        /* This is calculated to be the largest file size for a
 684         * dense, file such that the total number of
 685         * sectors in the file, including data and all indirect blocks,
 686         * does not exceed 2^32 -1
 687         * __u32 i_blocks representing the total number of
 688         * 512 bytes blocks of the file
 689         */
 690        upper_limit = (1LL << 32) - 1;
 691
 692        /* total blocks in file system block size */
 693        upper_limit >>= (bits - 9);
 694
 695
 696        /* indirect blocks */
 697        meta_blocks = 1;
 698        /* double indirect blocks */
 699        meta_blocks += 1 + (1LL << (bits-2));
 700        /* tripple indirect blocks */
 701        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 702
 703        upper_limit -= meta_blocks;
 704        upper_limit <<= bits;
 705
 706        res += 1LL << (bits-2);
 707        res += 1LL << (2*(bits-2));
 708        res += 1LL << (3*(bits-2));
 709        res <<= bits;
 710        if (res > upper_limit)
 711                res = upper_limit;
 712
 713        if (res > MAX_LFS_FILESIZE)
 714                res = MAX_LFS_FILESIZE;
 715
 716        return res;
 717}
 718
 719static unsigned long descriptor_loc(struct super_block *sb,
 720                                    unsigned long logic_sb_block,
 721                                    int nr)
 722{
 723        struct ext2_sb_info *sbi = EXT2_SB(sb);
 724        unsigned long bg, first_meta_bg;
 725        int has_super = 0;
 726        
 727        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 728
 729        if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 730            nr < first_meta_bg)
 731                return (logic_sb_block + nr + 1);
 732        bg = sbi->s_desc_per_block * nr;
 733        if (ext2_bg_has_super(sb, bg))
 734                has_super = 1;
 735
 736        return ext2_group_first_block_no(sb, bg) + has_super;
 737}
 738
 739static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 740{
 741        struct buffer_head * bh;
 742        struct ext2_sb_info * sbi;
 743        struct ext2_super_block * es;
 744        struct inode *root;
 745        unsigned long block;
 746        unsigned long sb_block = get_sb_block(&data);
 747        unsigned long logic_sb_block;
 748        unsigned long offset = 0;
 749        unsigned long def_mount_opts;
 750        long ret = -EINVAL;
 751        int blocksize = BLOCK_SIZE;
 752        int db_count;
 753        int i, j;
 754        __le32 features;
 755        int err;
 756
 757        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 758        if (!sbi)
 759                return -ENOMEM;
 760
 761        sbi->s_blockgroup_lock =
 762                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 763        if (!sbi->s_blockgroup_lock) {
 764                kfree(sbi);
 765                return -ENOMEM;
 766        }
 767        sb->s_fs_info = sbi;
 768        sbi->s_sb_block = sb_block;
 769
 770        /*
 771         * See what the current blocksize for the device is, and
 772         * use that as the blocksize.  Otherwise (or if the blocksize
 773         * is smaller than the default) use the default.
 774         * This is important for devices that have a hardware
 775         * sectorsize that is larger than the default.
 776         */
 777        blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 778        if (!blocksize) {
 779                printk ("EXT2-fs: unable to set blocksize\n");
 780                goto failed_sbi;
 781        }
 782
 783        /*
 784         * If the superblock doesn't start on a hardware sector boundary,
 785         * calculate the offset.  
 786         */
 787        if (blocksize != BLOCK_SIZE) {
 788                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 789                offset = (sb_block*BLOCK_SIZE) % blocksize;
 790        } else {
 791                logic_sb_block = sb_block;
 792        }
 793
 794        if (!(bh = sb_bread(sb, logic_sb_block))) {
 795                printk ("EXT2-fs: unable to read superblock\n");
 796                goto failed_sbi;
 797        }
 798        /*
 799         * Note: s_es must be initialized as soon as possible because
 800         *       some ext2 macro-instructions depend on its value
 801         */
 802        es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 803        sbi->s_es = es;
 804        sb->s_magic = le16_to_cpu(es->s_magic);
 805
 806        if (sb->s_magic != EXT2_SUPER_MAGIC)
 807                goto cantfind_ext2;
 808
 809        /* Set defaults before we parse the mount options */
 810        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 811        if (def_mount_opts & EXT2_DEFM_DEBUG)
 812                set_opt(sbi->s_mount_opt, DEBUG);
 813        if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 814                set_opt(sbi->s_mount_opt, GRPID);
 815        if (def_mount_opts & EXT2_DEFM_UID16)
 816                set_opt(sbi->s_mount_opt, NO_UID32);
 817#ifdef CONFIG_EXT2_FS_XATTR
 818        if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 819                set_opt(sbi->s_mount_opt, XATTR_USER);
 820#endif
 821#ifdef CONFIG_EXT2_FS_POSIX_ACL
 822        if (def_mount_opts & EXT2_DEFM_ACL)
 823                set_opt(sbi->s_mount_opt, POSIX_ACL);
 824#endif
 825        
 826        if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 827                set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 828        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 829                set_opt(sbi->s_mount_opt, ERRORS_CONT);
 830        else
 831                set_opt(sbi->s_mount_opt, ERRORS_RO);
 832
 833        sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 834        sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 835        
 836        set_opt(sbi->s_mount_opt, RESERVATION);
 837
 838        if (!parse_options ((char *) data, sbi))
 839                goto failed_mount;
 840
 841        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 842                ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 843                 MS_POSIXACL : 0);
 844
 845        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 846                                    EXT2_MOUNT_XIP if not */
 847
 848        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 849            (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 850             EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 851             EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 852                printk("EXT2-fs warning: feature flags set on rev 0 fs, "
 853                       "running e2fsck is recommended\n");
 854        /*
 855         * Check feature flags regardless of the revision level, since we
 856         * previously didn't change the revision level when setting the flags,
 857         * so there is a chance incompat flags are set on a rev 0 filesystem.
 858         */
 859        features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 860        if (features) {
 861                printk("EXT2-fs: %s: couldn't mount because of "
 862                       "unsupported optional features (%x).\n",
 863                       sb->s_id, le32_to_cpu(features));
 864                goto failed_mount;
 865        }
 866        if (!(sb->s_flags & MS_RDONLY) &&
 867            (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 868                printk("EXT2-fs: %s: couldn't mount RDWR because of "
 869                       "unsupported optional features (%x).\n",
 870                       sb->s_id, le32_to_cpu(features));
 871                goto failed_mount;
 872        }
 873
 874        blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 875
 876        if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
 877                if (!silent)
 878                        printk("XIP: Unsupported blocksize\n");
 879                goto failed_mount;
 880        }
 881
 882        /* If the blocksize doesn't match, re-read the thing.. */
 883        if (sb->s_blocksize != blocksize) {
 884                brelse(bh);
 885
 886                if (!sb_set_blocksize(sb, blocksize)) {
 887                        printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
 888                        goto failed_sbi;
 889                }
 890
 891                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 892                offset = (sb_block*BLOCK_SIZE) % blocksize;
 893                bh = sb_bread(sb, logic_sb_block);
 894                if(!bh) {
 895                        printk("EXT2-fs: Couldn't read superblock on "
 896                               "2nd try.\n");
 897                        goto failed_sbi;
 898                }
 899                es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 900                sbi->s_es = es;
 901                if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 902                        printk ("EXT2-fs: Magic mismatch, very weird !\n");
 903                        goto failed_mount;
 904                }
 905        }
 906
 907        sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 908
 909        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 910                sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 911                sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 912        } else {
 913                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 914                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 915                if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 916                    !is_power_of_2(sbi->s_inode_size) ||
 917                    (sbi->s_inode_size > blocksize)) {
 918                        printk ("EXT2-fs: unsupported inode size: %d\n",
 919                                sbi->s_inode_size);
 920                        goto failed_mount;
 921                }
 922        }
 923
 924        sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 925                                   le32_to_cpu(es->s_log_frag_size);
 926        if (sbi->s_frag_size == 0)
 927                goto cantfind_ext2;
 928        sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 929
 930        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 931        sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 932        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 933
 934        if (EXT2_INODE_SIZE(sb) == 0)
 935                goto cantfind_ext2;
 936        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 937        if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 938                goto cantfind_ext2;
 939        sbi->s_itb_per_group = sbi->s_inodes_per_group /
 940                                        sbi->s_inodes_per_block;
 941        sbi->s_desc_per_block = sb->s_blocksize /
 942                                        sizeof (struct ext2_group_desc);
 943        sbi->s_sbh = bh;
 944        sbi->s_mount_state = le16_to_cpu(es->s_state);
 945        sbi->s_addr_per_block_bits =
 946                ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 947        sbi->s_desc_per_block_bits =
 948                ilog2 (EXT2_DESC_PER_BLOCK(sb));
 949
 950        if (sb->s_magic != EXT2_SUPER_MAGIC)
 951                goto cantfind_ext2;
 952
 953        if (sb->s_blocksize != bh->b_size) {
 954                if (!silent)
 955                        printk ("VFS: Unsupported blocksize on dev "
 956                                "%s.\n", sb->s_id);
 957                goto failed_mount;
 958        }
 959
 960        if (sb->s_blocksize != sbi->s_frag_size) {
 961                printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
 962                        sbi->s_frag_size, sb->s_blocksize);
 963                goto failed_mount;
 964        }
 965
 966        if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 967                printk ("EXT2-fs: #blocks per group too big: %lu\n",
 968                        sbi->s_blocks_per_group);
 969                goto failed_mount;
 970        }
 971        if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 972                printk ("EXT2-fs: #fragments per group too big: %lu\n",
 973                        sbi->s_frags_per_group);
 974                goto failed_mount;
 975        }
 976        if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 977                printk ("EXT2-fs: #inodes per group too big: %lu\n",
 978                        sbi->s_inodes_per_group);
 979                goto failed_mount;
 980        }
 981
 982        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 983                goto cantfind_ext2;
 984        sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
 985                                le32_to_cpu(es->s_first_data_block) - 1)
 986                                        / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
 987        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 988                   EXT2_DESC_PER_BLOCK(sb);
 989        sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
 990        if (sbi->s_group_desc == NULL) {
 991                printk ("EXT2-fs: not enough memory\n");
 992                goto failed_mount;
 993        }
 994        bgl_lock_init(sbi->s_blockgroup_lock);
 995        sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
 996        if (!sbi->s_debts) {
 997                printk ("EXT2-fs: not enough memory\n");
 998                goto failed_mount_group_desc;
 999        }
1000        for (i = 0; i < db_count; i++) {
1001                block = descriptor_loc(sb, logic_sb_block, i);
1002                sbi->s_group_desc[i] = sb_bread(sb, block);
1003                if (!sbi->s_group_desc[i]) {
1004                        for (j = 0; j < i; j++)
1005                                brelse (sbi->s_group_desc[j]);
1006                        printk ("EXT2-fs: unable to read group descriptors\n");
1007                        goto failed_mount_group_desc;
1008                }
1009        }
1010        if (!ext2_check_descriptors (sb)) {
1011                printk ("EXT2-fs: group descriptors corrupted!\n");
1012                goto failed_mount2;
1013        }
1014        sbi->s_gdb_count = db_count;
1015        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1016        spin_lock_init(&sbi->s_next_gen_lock);
1017
1018        /* per fileystem reservation list head & lock */
1019        spin_lock_init(&sbi->s_rsv_window_lock);
1020        sbi->s_rsv_window_root = RB_ROOT;
1021        /*
1022         * Add a single, static dummy reservation to the start of the
1023         * reservation window list --- it gives us a placeholder for
1024         * append-at-start-of-list which makes the allocation logic
1025         * _much_ simpler.
1026         */
1027        sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1028        sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1029        sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1030        sbi->s_rsv_window_head.rsv_goal_size = 0;
1031        ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1032
1033        err = percpu_counter_init(&sbi->s_freeblocks_counter,
1034                                ext2_count_free_blocks(sb));
1035        if (!err) {
1036                err = percpu_counter_init(&sbi->s_freeinodes_counter,
1037                                ext2_count_free_inodes(sb));
1038        }
1039        if (!err) {
1040                err = percpu_counter_init(&sbi->s_dirs_counter,
1041                                ext2_count_dirs(sb));
1042        }
1043        if (err) {
1044                printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1045                goto failed_mount3;
1046        }
1047        /*
1048         * set up enough so that it can read an inode
1049         */
1050        sb->s_op = &ext2_sops;
1051        sb->s_export_op = &ext2_export_ops;
1052        sb->s_xattr = ext2_xattr_handlers;
1053        root = ext2_iget(sb, EXT2_ROOT_INO);
1054        if (IS_ERR(root)) {
1055                ret = PTR_ERR(root);
1056                goto failed_mount3;
1057        }
1058        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1059                iput(root);
1060                printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1061                goto failed_mount3;
1062        }
1063
1064        sb->s_root = d_alloc_root(root);
1065        if (!sb->s_root) {
1066                iput(root);
1067                printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1068                ret = -ENOMEM;
1069                goto failed_mount3;
1070        }
1071        if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1072                ext2_warning(sb, __func__,
1073                        "mounting ext3 filesystem as ext2");
1074        ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1075        return 0;
1076
1077cantfind_ext2:
1078        if (!silent)
1079                printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1080                       sb->s_id);
1081        goto failed_mount;
1082failed_mount3:
1083        percpu_counter_destroy(&sbi->s_freeblocks_counter);
1084        percpu_counter_destroy(&sbi->s_freeinodes_counter);
1085        percpu_counter_destroy(&sbi->s_dirs_counter);
1086failed_mount2:
1087        for (i = 0; i < db_count; i++)
1088                brelse(sbi->s_group_desc[i]);
1089failed_mount_group_desc:
1090        kfree(sbi->s_group_desc);
1091        kfree(sbi->s_debts);
1092failed_mount:
1093        brelse(bh);
1094failed_sbi:
1095        sb->s_fs_info = NULL;
1096        kfree(sbi);
1097        return ret;
1098}
1099
1100static void ext2_commit_super (struct super_block * sb,
1101                               struct ext2_super_block * es)
1102{
1103        es->s_wtime = cpu_to_le32(get_seconds());
1104        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1105        sb->s_dirt = 0;
1106}
1107
1108static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1109{
1110        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1111        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1112        es->s_wtime = cpu_to_le32(get_seconds());
1113        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1114        sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1115        sb->s_dirt = 0;
1116}
1117
1118/*
1119 * In the second extended file system, it is not necessary to
1120 * write the super block since we use a mapping of the
1121 * disk super block in a buffer.
1122 *
1123 * However, this function is still used to set the fs valid
1124 * flags to 0.  We need to set this flag to 0 since the fs
1125 * may have been checked while mounted and e2fsck may have
1126 * set s_state to EXT2_VALID_FS after some corrections.
1127 */
1128
1129void ext2_write_super (struct super_block * sb)
1130{
1131        struct ext2_super_block * es;
1132        lock_kernel();
1133        if (!(sb->s_flags & MS_RDONLY)) {
1134                es = EXT2_SB(sb)->s_es;
1135
1136                if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1137                        ext2_debug ("setting valid to 0\n");
1138                        es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1139                        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1140                        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1141                        es->s_mtime = cpu_to_le32(get_seconds());
1142                        ext2_sync_super(sb, es);
1143                } else
1144                        ext2_commit_super (sb, es);
1145        }
1146        sb->s_dirt = 0;
1147        unlock_kernel();
1148}
1149
1150static int ext2_remount (struct super_block * sb, int * flags, char * data)
1151{
1152        struct ext2_sb_info * sbi = EXT2_SB(sb);
1153        struct ext2_super_block * es;
1154        unsigned long old_mount_opt = sbi->s_mount_opt;
1155        struct ext2_mount_options old_opts;
1156        unsigned long old_sb_flags;
1157        int err;
1158
1159        /* Store the old options */
1160        old_sb_flags = sb->s_flags;
1161        old_opts.s_mount_opt = sbi->s_mount_opt;
1162        old_opts.s_resuid = sbi->s_resuid;
1163        old_opts.s_resgid = sbi->s_resgid;
1164
1165        /*
1166         * Allow the "check" option to be passed as a remount option.
1167         */
1168        if (!parse_options (data, sbi)) {
1169                err = -EINVAL;
1170                goto restore_opts;
1171        }
1172
1173        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1174                ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1175
1176        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1177                                    EXT2_MOUNT_XIP if not */
1178
1179        if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1180                printk("XIP: Unsupported blocksize\n");
1181                err = -EINVAL;
1182                goto restore_opts;
1183        }
1184
1185        es = sbi->s_es;
1186        if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1187            (old_mount_opt & EXT2_MOUNT_XIP)) &&
1188            invalidate_inodes(sb)) {
1189                ext2_warning(sb, __func__, "refusing change of xip flag "
1190                             "with busy inodes while remounting");
1191                sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1192                sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1193        }
1194        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1195                return 0;
1196        if (*flags & MS_RDONLY) {
1197                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1198                    !(sbi->s_mount_state & EXT2_VALID_FS))
1199                        return 0;
1200                /*
1201                 * OK, we are remounting a valid rw partition rdonly, so set
1202                 * the rdonly flag and then mark the partition as valid again.
1203                 */
1204                es->s_state = cpu_to_le16(sbi->s_mount_state);
1205                es->s_mtime = cpu_to_le32(get_seconds());
1206        } else {
1207                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1208                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
1209                if (ret) {
1210                        printk("EXT2-fs: %s: couldn't remount RDWR because of "
1211                               "unsupported optional features (%x).\n",
1212                               sb->s_id, le32_to_cpu(ret));
1213                        err = -EROFS;
1214                        goto restore_opts;
1215                }
1216                /*
1217                 * Mounting a RDONLY partition read-write, so reread and
1218                 * store the current valid flag.  (It may have been changed
1219                 * by e2fsck since we originally mounted the partition.)
1220                 */
1221                sbi->s_mount_state = le16_to_cpu(es->s_state);
1222                if (!ext2_setup_super (sb, es, 0))
1223                        sb->s_flags &= ~MS_RDONLY;
1224        }
1225        ext2_sync_super(sb, es);
1226        return 0;
1227restore_opts:
1228        sbi->s_mount_opt = old_opts.s_mount_opt;
1229        sbi->s_resuid = old_opts.s_resuid;
1230        sbi->s_resgid = old_opts.s_resgid;
1231        sb->s_flags = old_sb_flags;
1232        return err;
1233}
1234
1235static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1236{
1237        struct super_block *sb = dentry->d_sb;
1238        struct ext2_sb_info *sbi = EXT2_SB(sb);
1239        struct ext2_super_block *es = sbi->s_es;
1240        u64 fsid;
1241
1242        if (test_opt (sb, MINIX_DF))
1243                sbi->s_overhead_last = 0;
1244        else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1245                unsigned long i, overhead = 0;
1246                smp_rmb();
1247
1248                /*
1249                 * Compute the overhead (FS structures). This is constant
1250                 * for a given filesystem unless the number of block groups
1251                 * changes so we cache the previous value until it does.
1252                 */
1253
1254                /*
1255                 * All of the blocks before first_data_block are
1256                 * overhead
1257                 */
1258                overhead = le32_to_cpu(es->s_first_data_block);
1259
1260                /*
1261                 * Add the overhead attributed to the superblock and
1262                 * block group descriptors.  If the sparse superblocks
1263                 * feature is turned on, then not all groups have this.
1264                 */
1265                for (i = 0; i < sbi->s_groups_count; i++)
1266                        overhead += ext2_bg_has_super(sb, i) +
1267                                ext2_bg_num_gdb(sb, i);
1268
1269                /*
1270                 * Every block group has an inode bitmap, a block
1271                 * bitmap, and an inode table.
1272                 */
1273                overhead += (sbi->s_groups_count *
1274                             (2 + sbi->s_itb_per_group));
1275                sbi->s_overhead_last = overhead;
1276                smp_wmb();
1277                sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1278        }
1279
1280        buf->f_type = EXT2_SUPER_MAGIC;
1281        buf->f_bsize = sb->s_blocksize;
1282        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1283        buf->f_bfree = ext2_count_free_blocks(sb);
1284        es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1285        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1286        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1287                buf->f_bavail = 0;
1288        buf->f_files = le32_to_cpu(es->s_inodes_count);
1289        buf->f_ffree = ext2_count_free_inodes(sb);
1290        es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1291        buf->f_namelen = EXT2_NAME_LEN;
1292        fsid = le64_to_cpup((void *)es->s_uuid) ^
1293               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1294        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1295        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1296        return 0;
1297}
1298
1299static int ext2_get_sb(struct file_system_type *fs_type,
1300        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1301{
1302        return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1303}
1304
1305#ifdef CONFIG_QUOTA
1306
1307/* Read data from quotafile - avoid pagecache and such because we cannot afford
1308 * acquiring the locks... As quota files are never truncated and quota code
1309 * itself serializes the operations (and noone else should touch the files)
1310 * we don't have to be afraid of races */
1311static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1312                               size_t len, loff_t off)
1313{
1314        struct inode *inode = sb_dqopt(sb)->files[type];
1315        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1316        int err = 0;
1317        int offset = off & (sb->s_blocksize - 1);
1318        int tocopy;
1319        size_t toread;
1320        struct buffer_head tmp_bh;
1321        struct buffer_head *bh;
1322        loff_t i_size = i_size_read(inode);
1323
1324        if (off > i_size)
1325                return 0;
1326        if (off+len > i_size)
1327                len = i_size-off;
1328        toread = len;
1329        while (toread > 0) {
1330                tocopy = sb->s_blocksize - offset < toread ?
1331                                sb->s_blocksize - offset : toread;
1332
1333                tmp_bh.b_state = 0;
1334                err = ext2_get_block(inode, blk, &tmp_bh, 0);
1335                if (err < 0)
1336                        return err;
1337                if (!buffer_mapped(&tmp_bh))    /* A hole? */
1338                        memset(data, 0, tocopy);
1339                else {
1340                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1341                        if (!bh)
1342                                return -EIO;
1343                        memcpy(data, bh->b_data+offset, tocopy);
1344                        brelse(bh);
1345                }
1346                offset = 0;
1347                toread -= tocopy;
1348                data += tocopy;
1349                blk++;
1350        }
1351        return len;
1352}
1353
1354/* Write to quotafile */
1355static ssize_t ext2_quota_write(struct super_block *sb, int type,
1356                                const char *data, size_t len, loff_t off)
1357{
1358        struct inode *inode = sb_dqopt(sb)->files[type];
1359        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1360        int err = 0;
1361        int offset = off & (sb->s_blocksize - 1);
1362        int tocopy;
1363        size_t towrite = len;
1364        struct buffer_head tmp_bh;
1365        struct buffer_head *bh;
1366
1367        mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1368        while (towrite > 0) {
1369                tocopy = sb->s_blocksize - offset < towrite ?
1370                                sb->s_blocksize - offset : towrite;
1371
1372                tmp_bh.b_state = 0;
1373                err = ext2_get_block(inode, blk, &tmp_bh, 1);
1374                if (err < 0)
1375                        goto out;
1376                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1377                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1378                else
1379                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
1380                if (!bh) {
1381                        err = -EIO;
1382                        goto out;
1383                }
1384                lock_buffer(bh);
1385                memcpy(bh->b_data+offset, data, tocopy);
1386                flush_dcache_page(bh->b_page);
1387                set_buffer_uptodate(bh);
1388                mark_buffer_dirty(bh);
1389                unlock_buffer(bh);
1390                brelse(bh);
1391                offset = 0;
1392                towrite -= tocopy;
1393                data += tocopy;
1394                blk++;
1395        }
1396out:
1397        if (len == towrite)
1398                return err;
1399        if (inode->i_size < off+len-towrite)
1400                i_size_write(inode, off+len-towrite);
1401        inode->i_version++;
1402        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1403        mark_inode_dirty(inode);
1404        mutex_unlock(&inode->i_mutex);
1405        return len - towrite;
1406}
1407
1408#endif
1409
1410static struct file_system_type ext2_fs_type = {
1411        .owner          = THIS_MODULE,
1412        .name           = "ext2",
1413        .get_sb         = ext2_get_sb,
1414        .kill_sb        = kill_block_super,
1415        .fs_flags       = FS_REQUIRES_DEV,
1416};
1417
1418static int __init init_ext2_fs(void)
1419{
1420        int err = init_ext2_xattr();
1421        if (err)
1422                return err;
1423        err = init_inodecache();
1424        if (err)
1425                goto out1;
1426        err = register_filesystem(&ext2_fs_type);
1427        if (err)
1428                goto out;
1429        return 0;
1430out:
1431        destroy_inodecache();
1432out1:
1433        exit_ext2_xattr();
1434        return err;
1435}
1436
1437static void __exit exit_ext2_fs(void)
1438{
1439        unregister_filesystem(&ext2_fs_type);
1440        destroy_inodecache();
1441        exit_ext2_xattr();
1442}
1443
1444module_init(init_ext2_fs)
1445module_exit(exit_ext2_fs)
1446
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