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 <asm/uaccess.h>
  35#include "ext2.h"
  36#include "xattr.h"
  37#include "acl.h"
  38#include "xip.h"
  39
  40static void ext2_sync_super(struct super_block *sb,
  41                            struct ext2_super_block *es);
  42static int ext2_remount (struct super_block * sb, int * flags, char * data);
  43static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  44
  45void ext2_error (struct super_block * sb, const char * function,
  46                 const char * fmt, ...)
  47{
  48        va_list args;
  49        struct ext2_sb_info *sbi = EXT2_SB(sb);
  50        struct ext2_super_block *es = sbi->s_es;
  51
  52        if (!(sb->s_flags & MS_RDONLY)) {
  53                sbi->s_mount_state |= EXT2_ERROR_FS;
  54                es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  55                ext2_sync_super(sb, es);
  56        }
  57
  58        va_start(args, fmt);
  59        printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
  60        vprintk(fmt, args);
  61        printk("\n");
  62        va_end(args);
  63
  64        if (test_opt(sb, ERRORS_PANIC))
  65                panic("EXT2-fs panic from previous error\n");
  66        if (test_opt(sb, ERRORS_RO)) {
  67                printk("Remounting filesystem read-only\n");
  68                sb->s_flags |= MS_RDONLY;
  69        }
  70}
  71
  72void ext2_warning (struct super_block * sb, const char * function,
  73                   const char * fmt, ...)
  74{
  75        va_list args;
  76
  77        va_start(args, fmt);
  78        printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
  79               sb->s_id, function);
  80        vprintk(fmt, args);
  81        printk("\n");
  82        va_end(args);
  83}
  84
  85void ext2_update_dynamic_rev(struct super_block *sb)
  86{
  87        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
  88
  89        if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
  90                return;
  91
  92        ext2_warning(sb, __func__,
  93                     "updating to rev %d because of new feature flag, "
  94                     "running e2fsck is recommended",
  95                     EXT2_DYNAMIC_REV);
  96
  97        es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
  98        es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
  99        es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 100        /* leave es->s_feature_*compat flags alone */
 101        /* es->s_uuid will be set by e2fsck if empty */
 102
 103        /*
 104         * The rest of the superblock fields should be zero, and if not it
 105         * means they are likely already in use, so leave them alone.  We
 106         * can leave it up to e2fsck to clean up any inconsistencies there.
 107         */
 108}
 109
 110static void ext2_put_super (struct super_block * sb)
 111{
 112        int db_count;
 113        int i;
 114        struct ext2_sb_info *sbi = EXT2_SB(sb);
 115
 116        ext2_xattr_put_super(sb);
 117        if (!(sb->s_flags & MS_RDONLY)) {
 118                struct ext2_super_block *es = sbi->s_es;
 119
 120                es->s_state = cpu_to_le16(sbi->s_mount_state);
 121                ext2_sync_super(sb, es);
 122        }
 123        db_count = sbi->s_gdb_count;
 124        for (i = 0; i < db_count; i++)
 125                if (sbi->s_group_desc[i])
 126                        brelse (sbi->s_group_desc[i]);
 127        kfree(sbi->s_group_desc);
 128        kfree(sbi->s_debts);
 129        percpu_counter_destroy(&sbi->s_freeblocks_counter);
 130        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 131        percpu_counter_destroy(&sbi->s_dirs_counter);
 132        brelse (sbi->s_sbh);
 133        sb->s_fs_info = NULL;
 134        kfree(sbi);
 135
 136        return;
 137}
 138
 139static struct kmem_cache * ext2_inode_cachep;
 140
 141static struct inode *ext2_alloc_inode(struct super_block *sb)
 142{
 143        struct ext2_inode_info *ei;
 144        ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 145        if (!ei)
 146                return NULL;
 147#ifdef CONFIG_EXT2_FS_POSIX_ACL
 148        ei->i_acl = EXT2_ACL_NOT_CACHED;
 149        ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 150#endif
 151        ei->i_block_alloc_info = NULL;
 152        ei->vfs_inode.i_version = 1;
 153        return &ei->vfs_inode;
 154}
 155
 156static void ext2_destroy_inode(struct inode *inode)
 157{
 158        kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 159}
 160
 161static void init_once(struct kmem_cache * cachep, void *foo)
 162{
 163        struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 164
 165        rwlock_init(&ei->i_meta_lock);
 166#ifdef CONFIG_EXT2_FS_XATTR
 167        init_rwsem(&ei->xattr_sem);
 168#endif
 169        mutex_init(&ei->truncate_mutex);
 170        inode_init_once(&ei->vfs_inode);
 171}
 172
 173static int init_inodecache(void)
 174{
 175        ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 176                                             sizeof(struct ext2_inode_info),
 177                                             0, (SLAB_RECLAIM_ACCOUNT|
 178                                                SLAB_MEM_SPREAD),
 179                                             init_once);
 180        if (ext2_inode_cachep == NULL)
 181                return -ENOMEM;
 182        return 0;
 183}
 184
 185static void destroy_inodecache(void)
 186{
 187        kmem_cache_destroy(ext2_inode_cachep);
 188}
 189
 190static void ext2_clear_inode(struct inode *inode)
 191{
 192        struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
 193#ifdef CONFIG_EXT2_FS_POSIX_ACL
 194        struct ext2_inode_info *ei = EXT2_I(inode);
 195
 196        if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
 197                posix_acl_release(ei->i_acl);
 198                ei->i_acl = EXT2_ACL_NOT_CACHED;
 199        }
 200        if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
 201                posix_acl_release(ei->i_default_acl);
 202                ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 203        }
 204#endif
 205        ext2_discard_reservation(inode);
 206        EXT2_I(inode)->i_block_alloc_info = NULL;
 207        if (unlikely(rsv))
 208                kfree(rsv);
 209}
 210
 211static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
 212{
 213        struct super_block *sb = vfs->mnt_sb;
 214        struct ext2_sb_info *sbi = EXT2_SB(sb);
 215        struct ext2_super_block *es = sbi->s_es;
 216        unsigned long def_mount_opts;
 217
 218        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 219
 220        if (sbi->s_sb_block != 1)
 221                seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 222        if (test_opt(sb, MINIX_DF))
 223                seq_puts(seq, ",minixdf");
 224        if (test_opt(sb, GRPID))
 225                seq_puts(seq, ",grpid");
 226        if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 227                seq_puts(seq, ",nogrpid");
 228        if (sbi->s_resuid != EXT2_DEF_RESUID ||
 229            le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 230                seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 231        }
 232        if (sbi->s_resgid != EXT2_DEF_RESGID ||
 233            le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 234                seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 235        }
 236        if (test_opt(sb, ERRORS_RO)) {
 237                int def_errors = le16_to_cpu(es->s_errors);
 238
 239                if (def_errors == EXT2_ERRORS_PANIC ||
 240                    def_errors == EXT2_ERRORS_CONTINUE) {
 241                        seq_puts(seq, ",errors=remount-ro");
 242                }
 243        }
 244        if (test_opt(sb, ERRORS_CONT))
 245                seq_puts(seq, ",errors=continue");
 246        if (test_opt(sb, ERRORS_PANIC))
 247                seq_puts(seq, ",errors=panic");
 248        if (test_opt(sb, NO_UID32))
 249                seq_puts(seq, ",nouid32");
 250        if (test_opt(sb, DEBUG))
 251                seq_puts(seq, ",debug");
 252        if (test_opt(sb, OLDALLOC))
 253                seq_puts(seq, ",oldalloc");
 254
 255#ifdef CONFIG_EXT2_FS_XATTR
 256        if (test_opt(sb, XATTR_USER))
 257                seq_puts(seq, ",user_xattr");
 258        if (!test_opt(sb, XATTR_USER) &&
 259            (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 260                seq_puts(seq, ",nouser_xattr");
 261        }
 262#endif
 263
 264#ifdef CONFIG_EXT2_FS_POSIX_ACL
 265        if (test_opt(sb, POSIX_ACL))
 266                seq_puts(seq, ",acl");
 267        if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 268                seq_puts(seq, ",noacl");
 269#endif
 270
 271        if (test_opt(sb, NOBH))
 272                seq_puts(seq, ",nobh");
 273
 274#if defined(CONFIG_QUOTA)
 275        if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 276                seq_puts(seq, ",usrquota");
 277
 278        if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 279                seq_puts(seq, ",grpquota");
 280#endif
 281
 282#if defined(CONFIG_EXT2_FS_XIP)
 283        if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 284                seq_puts(seq, ",xip");
 285#endif
 286
 287        if (!test_opt(sb, RESERVATION))
 288                seq_puts(seq, ",noreservation");
 289
 290        return 0;
 291}
 292
 293#ifdef CONFIG_QUOTA
 294static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 295static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 296#endif
 297
 298static const struct super_operations ext2_sops = {
 299        .alloc_inode    = ext2_alloc_inode,
 300        .destroy_inode  = ext2_destroy_inode,
 301        .write_inode    = ext2_write_inode,
 302        .delete_inode   = ext2_delete_inode,
 303        .put_super      = ext2_put_super,
 304        .write_super    = ext2_write_super,
 305        .statfs         = ext2_statfs,
 306        .remount_fs     = ext2_remount,
 307        .clear_inode    = ext2_clear_inode,
 308        .show_options   = ext2_show_options,
 309#ifdef CONFIG_QUOTA
 310        .quota_read     = ext2_quota_read,
 311        .quota_write    = ext2_quota_write,
 312#endif
 313};
 314
 315static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 316                u64 ino, u32 generation)
 317{
 318        struct inode *inode;
 319
 320        if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 321                return ERR_PTR(-ESTALE);
 322        if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 323                return ERR_PTR(-ESTALE);
 324
 325        /* iget isn't really right if the inode is currently unallocated!!
 326         * ext2_read_inode currently does appropriate checks, but
 327         * it might be "neater" to call ext2_get_inode first and check
 328         * if the inode is valid.....
 329         */
 330        inode = ext2_iget(sb, ino);
 331        if (IS_ERR(inode))
 332                return ERR_CAST(inode);
 333        if (generation && inode->i_generation != generation) {
 334                /* we didn't find the right inode.. */
 335                iput(inode);
 336                return ERR_PTR(-ESTALE);
 337        }
 338        return inode;
 339}
 340
 341static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 342                int fh_len, int fh_type)
 343{
 344        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 345                                    ext2_nfs_get_inode);
 346}
 347
 348static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 349                int fh_len, int fh_type)
 350{
 351        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 352                                    ext2_nfs_get_inode);
 353}
 354
 355/* Yes, most of these are left as NULL!!
 356 * A NULL value implies the default, which works with ext2-like file
 357 * systems, but can be improved upon.
 358 * Currently only get_parent is required.
 359 */
 360static const struct export_operations ext2_export_ops = {
 361        .fh_to_dentry = ext2_fh_to_dentry,
 362        .fh_to_parent = ext2_fh_to_parent,
 363        .get_parent = ext2_get_parent,
 364};
 365
 366static unsigned long get_sb_block(void **data)
 367{
 368        unsigned long   sb_block;
 369        char            *options = (char *) *data;
 370
 371        if (!options || strncmp(options, "sb=", 3) != 0)
 372                return 1;       /* Default location */
 373        options += 3;
 374        sb_block = simple_strtoul(options, &options, 0);
 375        if (*options && *options != ',') {
 376                printk("EXT2-fs: Invalid sb specification: %s\n",
 377                       (char *) *data);
 378                return 1;
 379        }
 380        if (*options == ',')
 381                options++;
 382        *data = (void *) options;
 383        return sb_block;
 384}
 385
 386enum {
 387        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 388        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 389        Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 390        Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 391        Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 392        Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 393};
 394
 395static match_table_t tokens = {
 396        {Opt_bsd_df, "bsddf"},
 397        {Opt_minix_df, "minixdf"},
 398        {Opt_grpid, "grpid"},
 399        {Opt_grpid, "bsdgroups"},
 400        {Opt_nogrpid, "nogrpid"},
 401        {Opt_nogrpid, "sysvgroups"},
 402        {Opt_resgid, "resgid=%u"},
 403        {Opt_resuid, "resuid=%u"},
 404        {Opt_sb, "sb=%u"},
 405        {Opt_err_cont, "errors=continue"},
 406        {Opt_err_panic, "errors=panic"},
 407        {Opt_err_ro, "errors=remount-ro"},
 408        {Opt_nouid32, "nouid32"},
 409        {Opt_nocheck, "check=none"},
 410        {Opt_nocheck, "nocheck"},
 411        {Opt_debug, "debug"},
 412        {Opt_oldalloc, "oldalloc"},
 413        {Opt_orlov, "orlov"},
 414        {Opt_nobh, "nobh"},
 415        {Opt_user_xattr, "user_xattr"},
 416        {Opt_nouser_xattr, "nouser_xattr"},
 417        {Opt_acl, "acl"},
 418        {Opt_noacl, "noacl"},
 419        {Opt_xip, "xip"},
 420        {Opt_grpquota, "grpquota"},
 421        {Opt_ignore, "noquota"},
 422        {Opt_quota, "quota"},
 423        {Opt_usrquota, "usrquota"},
 424        {Opt_reservation, "reservation"},
 425        {Opt_noreservation, "noreservation"},
 426        {Opt_err, NULL}
 427};
 428
 429static int parse_options (char * options,
 430                          struct ext2_sb_info *sbi)
 431{
 432        char * p;
 433        substring_t args[MAX_OPT_ARGS];
 434        int option;
 435
 436        if (!options)
 437                return 1;
 438
 439        while ((p = strsep (&options, ",")) != NULL) {
 440                int token;
 441                if (!*p)
 442                        continue;
 443
 444                token = match_token(p, tokens, args);
 445                switch (token) {
 446                case Opt_bsd_df:
 447                        clear_opt (sbi->s_mount_opt, MINIX_DF);
 448                        break;
 449                case Opt_minix_df:
 450                        set_opt (sbi->s_mount_opt, MINIX_DF);
 451                        break;
 452                case Opt_grpid:
 453                        set_opt (sbi->s_mount_opt, GRPID);
 454                        break;
 455                case Opt_nogrpid:
 456                        clear_opt (sbi->s_mount_opt, GRPID);
 457                        break;
 458                case Opt_resuid:
 459                        if (match_int(&args[0], &option))
 460                                return 0;
 461                        sbi->s_resuid = option;
 462                        break;
 463                case Opt_resgid:
 464                        if (match_int(&args[0], &option))
 465                                return 0;
 466                        sbi->s_resgid = option;
 467                        break;
 468                case Opt_sb:
 469                        /* handled by get_sb_block() instead of here */
 470                        /* *sb_block = match_int(&args[0]); */
 471                        break;
 472                case Opt_err_panic:
 473                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 474                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 475                        set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 476                        break;
 477                case Opt_err_ro:
 478                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 479                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 480                        set_opt (sbi->s_mount_opt, ERRORS_RO);
 481                        break;
 482                case Opt_err_cont:
 483                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 484                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 485                        set_opt (sbi->s_mount_opt, ERRORS_CONT);
 486                        break;
 487                case Opt_nouid32:
 488                        set_opt (sbi->s_mount_opt, NO_UID32);
 489                        break;
 490                case Opt_nocheck:
 491                        clear_opt (sbi->s_mount_opt, CHECK);
 492                        break;
 493                case Opt_debug:
 494                        set_opt (sbi->s_mount_opt, DEBUG);
 495                        break;
 496                case Opt_oldalloc:
 497                        set_opt (sbi->s_mount_opt, OLDALLOC);
 498                        break;
 499                case Opt_orlov:
 500                        clear_opt (sbi->s_mount_opt, OLDALLOC);
 501                        break;
 502                case Opt_nobh:
 503                        set_opt (sbi->s_mount_opt, NOBH);
 504                        break;
 505#ifdef CONFIG_EXT2_FS_XATTR
 506                case Opt_user_xattr:
 507                        set_opt (sbi->s_mount_opt, XATTR_USER);
 508                        break;
 509                case Opt_nouser_xattr:
 510                        clear_opt (sbi->s_mount_opt, XATTR_USER);
 511                        break;
 512#else
 513                case Opt_user_xattr:
 514                case Opt_nouser_xattr:
 515                        printk("EXT2 (no)user_xattr options not supported\n");
 516                        break;
 517#endif
 518#ifdef CONFIG_EXT2_FS_POSIX_ACL
 519                case Opt_acl:
 520                        set_opt(sbi->s_mount_opt, POSIX_ACL);
 521                        break;
 522                case Opt_noacl:
 523                        clear_opt(sbi->s_mount_opt, POSIX_ACL);
 524                        break;
 525#else
 526                case Opt_acl:
 527                case Opt_noacl:
 528                        printk("EXT2 (no)acl options not supported\n");
 529                        break;
 530#endif
 531                case Opt_xip:
 532#ifdef CONFIG_EXT2_FS_XIP
 533                        set_opt (sbi->s_mount_opt, XIP);
 534#else
 535                        printk("EXT2 xip option not supported\n");
 536#endif
 537                        break;
 538
 539#if defined(CONFIG_QUOTA)
 540                case Opt_quota:
 541                case Opt_usrquota:
 542                        set_opt(sbi->s_mount_opt, USRQUOTA);
 543                        break;
 544
 545                case Opt_grpquota:
 546                        set_opt(sbi->s_mount_opt, GRPQUOTA);
 547                        break;
 548#else
 549                case Opt_quota:
 550                case Opt_usrquota:
 551                case Opt_grpquota:
 552                        printk(KERN_ERR
 553                                "EXT2-fs: quota operations not supported.\n");
 554
 555                        break;
 556#endif
 557
 558                case Opt_reservation:
 559                        set_opt(sbi->s_mount_opt, RESERVATION);
 560                        printk("reservations ON\n");
 561                        break;
 562                case Opt_noreservation:
 563                        clear_opt(sbi->s_mount_opt, RESERVATION);
 564                        printk("reservations OFF\n");
 565                        break;
 566                case Opt_ignore:
 567                        break;
 568                default:
 569                        return 0;
 570                }
 571        }
 572        return 1;
 573}
 574
 575static int ext2_setup_super (struct super_block * sb,
 576                              struct ext2_super_block * es,
 577                              int read_only)
 578{
 579        int res = 0;
 580        struct ext2_sb_info *sbi = EXT2_SB(sb);
 581
 582        if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 583                printk ("EXT2-fs warning: revision level too high, "
 584                        "forcing read-only mode\n");
 585                res = MS_RDONLY;
 586        }
 587        if (read_only)
 588                return res;
 589        if (!(sbi->s_mount_state & EXT2_VALID_FS))
 590                printk ("EXT2-fs warning: mounting unchecked fs, "
 591                        "running e2fsck is recommended\n");
 592        else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 593                printk ("EXT2-fs warning: mounting fs with errors, "
 594                        "running e2fsck is recommended\n");
 595        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 596                 le16_to_cpu(es->s_mnt_count) >=
 597                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 598                printk ("EXT2-fs warning: maximal mount count reached, "
 599                        "running e2fsck is recommended\n");
 600        else if (le32_to_cpu(es->s_checkinterval) &&
 601                (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 602                printk ("EXT2-fs warning: checktime reached, "
 603                        "running e2fsck is recommended\n");
 604        if (!le16_to_cpu(es->s_max_mnt_count))
 605                es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 606        le16_add_cpu(&es->s_mnt_count, 1);
 607        ext2_write_super(sb);
 608        if (test_opt (sb, DEBUG))
 609                printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
 610                        "bpg=%lu, ipg=%lu, mo=%04lx]\n",
 611                        EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 612                        sbi->s_frag_size,
 613                        sbi->s_groups_count,
 614                        EXT2_BLOCKS_PER_GROUP(sb),
 615                        EXT2_INODES_PER_GROUP(sb),
 616                        sbi->s_mount_opt);
 617        return res;
 618}
 619
 620static int ext2_check_descriptors(struct super_block *sb)
 621{
 622        int i;
 623        struct ext2_sb_info *sbi = EXT2_SB(sb);
 624
 625        ext2_debug ("Checking group descriptors");
 626
 627        for (i = 0; i < sbi->s_groups_count; i++) {
 628                struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 629                ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 630                ext2_fsblk_t last_block;
 631
 632                if (i == sbi->s_groups_count - 1)
 633                        last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 634                else
 635                        last_block = first_block +
 636                                (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 637
 638                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 639                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 640                {
 641                        ext2_error (sb, "ext2_check_descriptors",
 642                                    "Block bitmap for group %d"
 643                                    " not in group (block %lu)!",
 644                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 645                        return 0;
 646                }
 647                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 648                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 649                {
 650                        ext2_error (sb, "ext2_check_descriptors",
 651                                    "Inode bitmap for group %d"
 652                                    " not in group (block %lu)!",
 653                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 654                        return 0;
 655                }
 656                if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 657                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 658                    last_block)
 659                {
 660                        ext2_error (sb, "ext2_check_descriptors",
 661                                    "Inode table for group %d"
 662                                    " not in group (block %lu)!",
 663                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 664                        return 0;
 665                }
 666        }
 667        return 1;
 668}
 669
 670/*
 671 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 672 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 673 * We need to be 1 filesystem block less than the 2^32 sector limit.
 674 */
 675static loff_t ext2_max_size(int bits)
 676{
 677        loff_t res = EXT2_NDIR_BLOCKS;
 678        int meta_blocks;
 679        loff_t upper_limit;
 680
 681        /* This is calculated to be the largest file size for a
 682         * dense, file such that the total number of
 683         * sectors in the file, including data and all indirect blocks,
 684         * does not exceed 2^32 -1
 685         * __u32 i_blocks representing the total number of
 686         * 512 bytes blocks of the file
 687         */
 688        upper_limit = (1LL << 32) - 1;
 689
 690        /* total blocks in file system block size */
 691        upper_limit >>= (bits - 9);
 692
 693
 694        /* indirect blocks */
 695        meta_blocks = 1;
 696        /* double indirect blocks */
 697        meta_blocks += 1 + (1LL << (bits-2));
 698        /* tripple indirect blocks */
 699        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 700
 701        upper_limit -= meta_blocks;
 702        upper_limit <<= bits;
 703
 704        res += 1LL << (bits-2);
 705        res += 1LL << (2*(bits-2));
 706        res += 1LL << (3*(bits-2));
 707        res <<= bits;
 708        if (res > upper_limit)
 709                res = upper_limit;
 710
 711        if (res > MAX_LFS_FILESIZE)
 712                res = MAX_LFS_FILESIZE;
 713
 714        return res;
 715}
 716
 717static unsigned long descriptor_loc(struct super_block *sb,
 718                                    unsigned long logic_sb_block,
 719                                    int nr)
 720{
 721        struct ext2_sb_info *sbi = EXT2_SB(sb);
 722        unsigned long bg, first_meta_bg;
 723        int has_super = 0;
 724        
 725        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 726
 727        if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 728            nr < first_meta_bg)
 729                return (logic_sb_block + nr + 1);
 730        bg = sbi->s_desc_per_block * nr;
 731        if (ext2_bg_has_super(sb, bg))
 732                has_super = 1;
 733
 734        return ext2_group_first_block_no(sb, bg) + has_super;
 735}
 736
 737static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 738{
 739        struct buffer_head * bh;
 740        struct ext2_sb_info * sbi;
 741        struct ext2_super_block * es;
 742        struct inode *root;
 743        unsigned long block;
 744        unsigned long sb_block = get_sb_block(&data);
 745        unsigned long logic_sb_block;
 746        unsigned long offset = 0;
 747        unsigned long def_mount_opts;
 748        long ret = -EINVAL;
 749        int blocksize = BLOCK_SIZE;
 750        int db_count;
 751        int i, j;
 752        __le32 features;
 753        int err;
 754
 755        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 756        if (!sbi)
 757                return -ENOMEM;
 758        sb->s_fs_info = sbi;
 759        sbi->s_sb_block = sb_block;
 760
 761        /*
 762         * See what the current blocksize for the device is, and
 763         * use that as the blocksize.  Otherwise (or if the blocksize
 764         * is smaller than the default) use the default.
 765         * This is important for devices that have a hardware
 766         * sectorsize that is larger than the default.
 767         */
 768        blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 769        if (!blocksize) {
 770                printk ("EXT2-fs: unable to set blocksize\n");
 771                goto failed_sbi;
 772        }
 773
 774        /*
 775         * If the superblock doesn't start on a hardware sector boundary,
 776         * calculate the offset.  
 777         */
 778        if (blocksize != BLOCK_SIZE) {
 779                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 780                offset = (sb_block*BLOCK_SIZE) % blocksize;
 781        } else {
 782                logic_sb_block = sb_block;
 783        }
 784
 785        if (!(bh = sb_bread(sb, logic_sb_block))) {
 786                printk ("EXT2-fs: unable to read superblock\n");
 787                goto failed_sbi;
 788        }
 789        /*
 790         * Note: s_es must be initialized as soon as possible because
 791         *       some ext2 macro-instructions depend on its value
 792         */
 793        es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 794        sbi->s_es = es;
 795        sb->s_magic = le16_to_cpu(es->s_magic);
 796
 797        if (sb->s_magic != EXT2_SUPER_MAGIC)
 798                goto cantfind_ext2;
 799
 800        /* Set defaults before we parse the mount options */
 801        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 802        if (def_mount_opts & EXT2_DEFM_DEBUG)
 803                set_opt(sbi->s_mount_opt, DEBUG);
 804        if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 805                set_opt(sbi->s_mount_opt, GRPID);
 806        if (def_mount_opts & EXT2_DEFM_UID16)
 807                set_opt(sbi->s_mount_opt, NO_UID32);
 808#ifdef CONFIG_EXT2_FS_XATTR
 809        if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 810                set_opt(sbi->s_mount_opt, XATTR_USER);
 811#endif
 812#ifdef CONFIG_EXT2_FS_POSIX_ACL
 813        if (def_mount_opts & EXT2_DEFM_ACL)
 814                set_opt(sbi->s_mount_opt, POSIX_ACL);
 815#endif
 816        
 817        if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 818                set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 819        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 820                set_opt(sbi->s_mount_opt, ERRORS_CONT);
 821        else
 822                set_opt(sbi->s_mount_opt, ERRORS_RO);
 823
 824        sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 825        sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 826        
 827        set_opt(sbi->s_mount_opt, RESERVATION);
 828
 829        if (!parse_options ((char *) data, sbi))
 830                goto failed_mount;
 831
 832        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 833                ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 834                 MS_POSIXACL : 0);
 835
 836        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 837                                    EXT2_MOUNT_XIP if not */
 838
 839        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 840            (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 841             EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 842             EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 843                printk("EXT2-fs warning: feature flags set on rev 0 fs, "
 844                       "running e2fsck is recommended\n");
 845        /*
 846         * Check feature flags regardless of the revision level, since we
 847         * previously didn't change the revision level when setting the flags,
 848         * so there is a chance incompat flags are set on a rev 0 filesystem.
 849         */
 850        features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 851        if (features) {
 852                printk("EXT2-fs: %s: couldn't mount because of "
 853                       "unsupported optional features (%x).\n",
 854                       sb->s_id, le32_to_cpu(features));
 855                goto failed_mount;
 856        }
 857        if (!(sb->s_flags & MS_RDONLY) &&
 858            (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 859                printk("EXT2-fs: %s: couldn't mount RDWR because of "
 860                       "unsupported optional features (%x).\n",
 861                       sb->s_id, le32_to_cpu(features));
 862                goto failed_mount;
 863        }
 864
 865        blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 866
 867        if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
 868                if (!silent)
 869                        printk("XIP: Unsupported blocksize\n");
 870                goto failed_mount;
 871        }
 872
 873        /* If the blocksize doesn't match, re-read the thing.. */
 874        if (sb->s_blocksize != blocksize) {
 875                brelse(bh);
 876
 877                if (!sb_set_blocksize(sb, blocksize)) {
 878                        printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
 879                        goto failed_sbi;
 880                }
 881
 882                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 883                offset = (sb_block*BLOCK_SIZE) % blocksize;
 884                bh = sb_bread(sb, logic_sb_block);
 885                if(!bh) {
 886                        printk("EXT2-fs: Couldn't read superblock on "
 887                               "2nd try.\n");
 888                        goto failed_sbi;
 889                }
 890                es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 891                sbi->s_es = es;
 892                if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 893                        printk ("EXT2-fs: Magic mismatch, very weird !\n");
 894                        goto failed_mount;
 895                }
 896        }
 897
 898        sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 899
 900        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 901                sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 902                sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 903        } else {
 904                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 905                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 906                if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 907                    !is_power_of_2(sbi->s_inode_size) ||
 908                    (sbi->s_inode_size > blocksize)) {
 909                        printk ("EXT2-fs: unsupported inode size: %d\n",
 910                                sbi->s_inode_size);
 911                        goto failed_mount;
 912                }
 913        }
 914
 915        sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 916                                   le32_to_cpu(es->s_log_frag_size);
 917        if (sbi->s_frag_size == 0)
 918                goto cantfind_ext2;
 919        sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 920
 921        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 922        sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 923        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 924
 925        if (EXT2_INODE_SIZE(sb) == 0)
 926                goto cantfind_ext2;
 927        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 928        if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 929                goto cantfind_ext2;
 930        sbi->s_itb_per_group = sbi->s_inodes_per_group /
 931                                        sbi->s_inodes_per_block;
 932        sbi->s_desc_per_block = sb->s_blocksize /
 933                                        sizeof (struct ext2_group_desc);
 934        sbi->s_sbh = bh;
 935        sbi->s_mount_state = le16_to_cpu(es->s_state);
 936        sbi->s_addr_per_block_bits =
 937                ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 938        sbi->s_desc_per_block_bits =
 939                ilog2 (EXT2_DESC_PER_BLOCK(sb));
 940
 941        if (sb->s_magic != EXT2_SUPER_MAGIC)
 942                goto cantfind_ext2;
 943
 944        if (sb->s_blocksize != bh->b_size) {
 945                if (!silent)
 946                        printk ("VFS: Unsupported blocksize on dev "
 947                                "%s.\n", sb->s_id);
 948                goto failed_mount;
 949        }
 950
 951        if (sb->s_blocksize != sbi->s_frag_size) {
 952                printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
 953                        sbi->s_frag_size, sb->s_blocksize);
 954                goto failed_mount;
 955        }
 956
 957        if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 958                printk ("EXT2-fs: #blocks per group too big: %lu\n",
 959                        sbi->s_blocks_per_group);
 960                goto failed_mount;
 961        }
 962        if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 963                printk ("EXT2-fs: #fragments per group too big: %lu\n",
 964                        sbi->s_frags_per_group);
 965                goto failed_mount;
 966        }
 967        if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 968                printk ("EXT2-fs: #inodes per group too big: %lu\n",
 969                        sbi->s_inodes_per_group);
 970                goto failed_mount;
 971        }
 972
 973        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 974                goto cantfind_ext2;
 975        sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
 976                                le32_to_cpu(es->s_first_data_block) - 1)
 977                                        / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
 978        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 979                   EXT2_DESC_PER_BLOCK(sb);
 980        sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
 981        if (sbi->s_group_desc == NULL) {
 982                printk ("EXT2-fs: not enough memory\n");
 983                goto failed_mount;
 984        }
 985        bgl_lock_init(&sbi->s_blockgroup_lock);
 986        sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
 987        if (!sbi->s_debts) {
 988                printk ("EXT2-fs: not enough memory\n");
 989                goto failed_mount_group_desc;
 990        }
 991        for (i = 0; i < db_count; i++) {
 992                block = descriptor_loc(sb, logic_sb_block, i);
 993                sbi->s_group_desc[i] = sb_bread(sb, block);
 994                if (!sbi->s_group_desc[i]) {
 995                        for (j = 0; j < i; j++)
 996                                brelse (sbi->s_group_desc[j]);
 997                        printk ("EXT2-fs: unable to read group descriptors\n");
 998                        goto failed_mount_group_desc;
 999                }
1000        }
1001        if (!ext2_check_descriptors (sb)) {
1002                printk ("EXT2-fs: group descriptors corrupted!\n");
1003                goto failed_mount2;
1004        }
1005        sbi->s_gdb_count = db_count;
1006        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1007        spin_lock_init(&sbi->s_next_gen_lock);
1008
1009        /* per fileystem reservation list head & lock */
1010        spin_lock_init(&sbi->s_rsv_window_lock);
1011        sbi->s_rsv_window_root = RB_ROOT;
1012        /*
1013         * Add a single, static dummy reservation to the start of the
1014         * reservation window list --- it gives us a placeholder for
1015         * append-at-start-of-list which makes the allocation logic
1016         * _much_ simpler.
1017         */
1018        sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1019        sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1020        sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1021        sbi->s_rsv_window_head.rsv_goal_size = 0;
1022        ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1023
1024        err = percpu_counter_init(&sbi->s_freeblocks_counter,
1025                                ext2_count_free_blocks(sb));
1026        if (!err) {
1027                err = percpu_counter_init(&sbi->s_freeinodes_counter,
1028                                ext2_count_free_inodes(sb));
1029        }
1030        if (!err) {
1031                err = percpu_counter_init(&sbi->s_dirs_counter,
1032                                ext2_count_dirs(sb));
1033        }
1034        if (err) {
1035                printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1036                goto failed_mount3;
1037        }
1038        /*
1039         * set up enough so that it can read an inode
1040         */
1041        sb->s_op = &ext2_sops;
1042        sb->s_export_op = &ext2_export_ops;
1043        sb->s_xattr = ext2_xattr_handlers;
1044        root = ext2_iget(sb, EXT2_ROOT_INO);
1045        if (IS_ERR(root)) {
1046                ret = PTR_ERR(root);
1047                goto failed_mount3;
1048        }
1049        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1050                iput(root);
1051                printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1052                goto failed_mount3;
1053        }
1054
1055        sb->s_root = d_alloc_root(root);
1056        if (!sb->s_root) {
1057                iput(root);
1058                printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1059                ret = -ENOMEM;
1060                goto failed_mount3;
1061        }
1062        if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1063                ext2_warning(sb, __func__,
1064                        "mounting ext3 filesystem as ext2");
1065        ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1066        return 0;
1067
1068cantfind_ext2:
1069        if (!silent)
1070                printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1071                       sb->s_id);
1072        goto failed_mount;
1073failed_mount3:
1074        percpu_counter_destroy(&sbi->s_freeblocks_counter);
1075        percpu_counter_destroy(&sbi->s_freeinodes_counter);
1076        percpu_counter_destroy(&sbi->s_dirs_counter);
1077failed_mount2:
1078        for (i = 0; i < db_count; i++)
1079                brelse(sbi->s_group_desc[i]);
1080failed_mount_group_desc:
1081        kfree(sbi->s_group_desc);
1082        kfree(sbi->s_debts);
1083failed_mount:
1084        brelse(bh);
1085failed_sbi:
1086        sb->s_fs_info = NULL;
1087        kfree(sbi);
1088        return ret;
1089}
1090
1091static void ext2_commit_super (struct super_block * sb,
1092                               struct ext2_super_block * es)
1093{
1094        es->s_wtime = cpu_to_le32(get_seconds());
1095        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1096        sb->s_dirt = 0;
1097}
1098
1099static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1100{
1101        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1102        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1103        es->s_wtime = cpu_to_le32(get_seconds());
1104        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1105        sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1106        sb->s_dirt = 0;
1107}
1108
1109/*
1110 * In the second extended file system, it is not necessary to
1111 * write the super block since we use a mapping of the
1112 * disk super block in a buffer.
1113 *
1114 * However, this function is still used to set the fs valid
1115 * flags to 0.  We need to set this flag to 0 since the fs
1116 * may have been checked while mounted and e2fsck may have
1117 * set s_state to EXT2_VALID_FS after some corrections.
1118 */
1119
1120void ext2_write_super (struct super_block * sb)
1121{
1122        struct ext2_super_block * es;
1123        lock_kernel();
1124        if (!(sb->s_flags & MS_RDONLY)) {
1125                es = EXT2_SB(sb)->s_es;
1126
1127                if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1128                        ext2_debug ("setting valid to 0\n");
1129                        es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1130                        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1131                        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1132                        es->s_mtime = cpu_to_le32(get_seconds());
1133                        ext2_sync_super(sb, es);
1134                } else
1135                        ext2_commit_super (sb, es);
1136        }
1137        sb->s_dirt = 0;
1138        unlock_kernel();
1139}
1140
1141static int ext2_remount (struct super_block * sb, int * flags, char * data)
1142{
1143        struct ext2_sb_info * sbi = EXT2_SB(sb);
1144        struct ext2_super_block * es;
1145        unsigned long old_mount_opt = sbi->s_mount_opt;
1146        struct ext2_mount_options old_opts;
1147        unsigned long old_sb_flags;
1148        int err;
1149
1150        /* Store the old options */
1151        old_sb_flags = sb->s_flags;
1152        old_opts.s_mount_opt = sbi->s_mount_opt;
1153        old_opts.s_resuid = sbi->s_resuid;
1154        old_opts.s_resgid = sbi->s_resgid;
1155
1156        /*
1157         * Allow the "check" option to be passed as a remount option.
1158         */
1159        if (!parse_options (data, sbi)) {
1160                err = -EINVAL;
1161                goto restore_opts;
1162        }
1163
1164        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1165                ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1166
1167        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1168                                    EXT2_MOUNT_XIP if not */
1169
1170        if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1171                printk("XIP: Unsupported blocksize\n");
1172                err = -EINVAL;
1173                goto restore_opts;
1174        }
1175
1176        es = sbi->s_es;
1177        if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1178            (old_mount_opt & EXT2_MOUNT_XIP)) &&
1179            invalidate_inodes(sb))
1180                ext2_warning(sb, __func__, "busy inodes while remounting "\
1181                             "xip remain in cache (no functional problem)");
1182        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1183                return 0;
1184        if (*flags & MS_RDONLY) {
1185                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1186                    !(sbi->s_mount_state & EXT2_VALID_FS))
1187                        return 0;
1188                /*
1189                 * OK, we are remounting a valid rw partition rdonly, so set
1190                 * the rdonly flag and then mark the partition as valid again.
1191                 */
1192                es->s_state = cpu_to_le16(sbi->s_mount_state);
1193                es->s_mtime = cpu_to_le32(get_seconds());
1194        } else {
1195                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1196                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
1197                if (ret) {
1198                        printk("EXT2-fs: %s: couldn't remount RDWR because of "
1199                               "unsupported optional features (%x).\n",
1200                               sb->s_id, le32_to_cpu(ret));
1201                        err = -EROFS;
1202                        goto restore_opts;
1203                }
1204                /*
1205                 * Mounting a RDONLY partition read-write, so reread and
1206                 * store the current valid flag.  (It may have been changed
1207                 * by e2fsck since we originally mounted the partition.)
1208                 */
1209                sbi->s_mount_state = le16_to_cpu(es->s_state);
1210                if (!ext2_setup_super (sb, es, 0))
1211                        sb->s_flags &= ~MS_RDONLY;
1212        }
1213        ext2_sync_super(sb, es);
1214        return 0;
1215restore_opts:
1216        sbi->s_mount_opt = old_opts.s_mount_opt;
1217        sbi->s_resuid = old_opts.s_resuid;
1218        sbi->s_resgid = old_opts.s_resgid;
1219        sb->s_flags = old_sb_flags;
1220        return err;
1221}
1222
1223static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1224{
1225        struct super_block *sb = dentry->d_sb;
1226        struct ext2_sb_info *sbi = EXT2_SB(sb);
1227        struct ext2_super_block *es = sbi->s_es;
1228        u64 fsid;
1229
1230        if (test_opt (sb, MINIX_DF))
1231                sbi->s_overhead_last = 0;
1232        else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1233                unsigned long i, overhead = 0;
1234                smp_rmb();
1235
1236                /*
1237                 * Compute the overhead (FS structures). This is constant
1238                 * for a given filesystem unless the number of block groups
1239                 * changes so we cache the previous value until it does.
1240                 */
1241
1242                /*
1243                 * All of the blocks before first_data_block are
1244                 * overhead
1245                 */
1246                overhead = le32_to_cpu(es->s_first_data_block);
1247
1248                /*
1249                 * Add the overhead attributed to the superblock and
1250                 * block group descriptors.  If the sparse superblocks
1251                 * feature is turned on, then not all groups have this.
1252                 */
1253                for (i = 0; i < sbi->s_groups_count; i++)
1254                        overhead += ext2_bg_has_super(sb, i) +
1255                                ext2_bg_num_gdb(sb, i);
1256
1257                /*
1258                 * Every block group has an inode bitmap, a block
1259                 * bitmap, and an inode table.
1260                 */
1261                overhead += (sbi->s_groups_count *
1262                             (2 + sbi->s_itb_per_group));
1263                sbi->s_overhead_last = overhead;
1264                smp_wmb();
1265                sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1266        }
1267
1268        buf->f_type = EXT2_SUPER_MAGIC;
1269        buf->f_bsize = sb->s_blocksize;
1270        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1271        buf->f_bfree = ext2_count_free_blocks(sb);
1272        es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1273        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1274        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1275                buf->f_bavail = 0;
1276        buf->f_files = le32_to_cpu(es->s_inodes_count);
1277        buf->f_ffree = ext2_count_free_inodes(sb);
1278        es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1279        buf->f_namelen = EXT2_NAME_LEN;
1280        fsid = le64_to_cpup((void *)es->s_uuid) ^
1281               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1282        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1283        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1284        return 0;
1285}
1286
1287static int ext2_get_sb(struct file_system_type *fs_type,
1288        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1289{
1290        return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1291}
1292
1293#ifdef CONFIG_QUOTA
1294
1295/* Read data from quotafile - avoid pagecache and such because we cannot afford
1296 * acquiring the locks... As quota files are never truncated and quota code
1297 * itself serializes the operations (and noone else should touch the files)
1298 * we don't have to be afraid of races */
1299static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1300                               size_t len, loff_t off)
1301{
1302        struct inode *inode = sb_dqopt(sb)->files[type];
1303        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1304        int err = 0;
1305        int offset = off & (sb->s_blocksize - 1);
1306        int tocopy;
1307        size_t toread;
1308        struct buffer_head tmp_bh;
1309        struct buffer_head *bh;
1310        loff_t i_size = i_size_read(inode);
1311
1312        if (off > i_size)
1313                return 0;
1314        if (off+len > i_size)
1315                len = i_size-off;
1316        toread = len;
1317        while (toread > 0) {
1318                tocopy = sb->s_blocksize - offset < toread ?
1319                                sb->s_blocksize - offset : toread;
1320
1321                tmp_bh.b_state = 0;
1322                err = ext2_get_block(inode, blk, &tmp_bh, 0);
1323                if (err < 0)
1324                        return err;
1325                if (!buffer_mapped(&tmp_bh))    /* A hole? */
1326                        memset(data, 0, tocopy);
1327                else {
1328                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1329                        if (!bh)
1330                                return -EIO;
1331                        memcpy(data, bh->b_data+offset, tocopy);
1332                        brelse(bh);
1333                }
1334                offset = 0;
1335                toread -= tocopy;
1336                data += tocopy;
1337                blk++;
1338        }
1339        return len;
1340}
1341
1342/* Write to quotafile */
1343static ssize_t ext2_quota_write(struct super_block *sb, int type,
1344                                const char *data, size_t len, loff_t off)
1345{
1346        struct inode *inode = sb_dqopt(sb)->files[type];
1347        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1348        int err = 0;
1349        int offset = off & (sb->s_blocksize - 1);
1350        int tocopy;
1351        size_t towrite = len;
1352        struct buffer_head tmp_bh;
1353        struct buffer_head *bh;
1354
1355        mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1356        while (towrite > 0) {
1357                tocopy = sb->s_blocksize - offset < towrite ?
1358                                sb->s_blocksize - offset : towrite;
1359
1360                tmp_bh.b_state = 0;
1361                err = ext2_get_block(inode, blk, &tmp_bh, 1);
1362                if (err < 0)
1363                        goto out;
1364                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1365                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1366                else
1367                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
1368                if (!bh) {
1369                        err = -EIO;
1370                        goto out;
1371                }
1372                lock_buffer(bh);
1373                memcpy(bh->b_data+offset, data, tocopy);
1374                flush_dcache_page(bh->b_page);
1375                set_buffer_uptodate(bh);
1376                mark_buffer_dirty(bh);
1377                unlock_buffer(bh);
1378                brelse(bh);
1379                offset = 0;
1380                towrite -= tocopy;
1381                data += tocopy;
1382                blk++;
1383        }
1384out:
1385        if (len == towrite)
1386                return err;
1387        if (inode->i_size < off+len-towrite)
1388                i_size_write(inode, off+len-towrite);
1389        inode->i_version++;
1390        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1391        mark_inode_dirty(inode);
1392        mutex_unlock(&inode->i_mutex);
1393        return len - towrite;
1394}
1395
1396#endif
1397
1398static struct file_system_type ext2_fs_type = {
1399        .owner          = THIS_MODULE,
1400        .name           = "ext2",
1401        .get_sb         = ext2_get_sb,
1402        .kill_sb        = kill_block_super,
1403        .fs_flags       = FS_REQUIRES_DEV,
1404};
1405
1406static int __init init_ext2_fs(void)
1407{
1408        int err = init_ext2_xattr();
1409        if (err)
1410                return err;
1411        err = init_inodecache();
1412        if (err)
1413                goto out1;
1414        err = register_filesystem(&ext2_fs_type);
1415        if (err)
1416                goto out;
1417        return 0;
1418out:
1419        destroy_inodecache();
1420out1:
1421        exit_ext2_xattr();
1422        return err;
1423}
1424
1425static void __exit exit_ext2_fs(void)
1426{
1427        unregister_filesystem(&ext2_fs_type);
1428        destroy_inodecache();
1429        exit_ext2_xattr();
1430}
1431
1432module_init(init_ext2_fs)
1433module_exit(exit_ext2_fs)
1434
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