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);
  45static int ext2_sync_fs(struct super_block *sb, int wait);
  46
  47void ext2_error (struct super_block * sb, const char * function,
  48                 const char * fmt, ...)
  49{
  50        va_list args;
  51        struct ext2_sb_info *sbi = EXT2_SB(sb);
  52        struct ext2_super_block *es = sbi->s_es;
  53
  54        if (!(sb->s_flags & MS_RDONLY)) {
  55                sbi->s_mount_state |= EXT2_ERROR_FS;
  56                es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  57                ext2_sync_super(sb, es);
  58        }
  59
  60        va_start(args, fmt);
  61        printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
  62        vprintk(fmt, args);
  63        printk("\n");
  64        va_end(args);
  65
  66        if (test_opt(sb, ERRORS_PANIC))
  67                panic("EXT2-fs panic from previous error\n");
  68        if (test_opt(sb, ERRORS_RO)) {
  69                printk("Remounting filesystem read-only\n");
  70                sb->s_flags |= MS_RDONLY;
  71        }
  72}
  73
  74void ext2_warning (struct super_block * sb, const char * function,
  75                   const char * fmt, ...)
  76{
  77        va_list args;
  78
  79        va_start(args, fmt);
  80        printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
  81               sb->s_id, function);
  82        vprintk(fmt, args);
  83        printk("\n");
  84        va_end(args);
  85}
  86
  87void ext2_update_dynamic_rev(struct super_block *sb)
  88{
  89        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
  90
  91        if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
  92                return;
  93
  94        ext2_warning(sb, __func__,
  95                     "updating to rev %d because of new feature flag, "
  96                     "running e2fsck is recommended",
  97                     EXT2_DYNAMIC_REV);
  98
  99        es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 100        es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 101        es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 102        /* leave es->s_feature_*compat flags alone */
 103        /* es->s_uuid will be set by e2fsck if empty */
 104
 105        /*
 106         * The rest of the superblock fields should be zero, and if not it
 107         * means they are likely already in use, so leave them alone.  We
 108         * can leave it up to e2fsck to clean up any inconsistencies there.
 109         */
 110}
 111
 112static void ext2_put_super (struct super_block * sb)
 113{
 114        int db_count;
 115        int i;
 116        struct ext2_sb_info *sbi = EXT2_SB(sb);
 117
 118        lock_kernel();
 119
 120        if (sb->s_dirt)
 121                ext2_write_super(sb);
 122
 123        ext2_xattr_put_super(sb);
 124        if (!(sb->s_flags & MS_RDONLY)) {
 125                struct ext2_super_block *es = sbi->s_es;
 126
 127                es->s_state = cpu_to_le16(sbi->s_mount_state);
 128                ext2_sync_super(sb, es);
 129        }
 130        db_count = sbi->s_gdb_count;
 131        for (i = 0; i < db_count; i++)
 132                if (sbi->s_group_desc[i])
 133                        brelse (sbi->s_group_desc[i]);
 134        kfree(sbi->s_group_desc);
 135        kfree(sbi->s_debts);
 136        percpu_counter_destroy(&sbi->s_freeblocks_counter);
 137        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 138        percpu_counter_destroy(&sbi->s_dirs_counter);
 139        brelse (sbi->s_sbh);
 140        sb->s_fs_info = NULL;
 141        kfree(sbi->s_blockgroup_lock);
 142        kfree(sbi);
 143
 144        unlock_kernel();
 145}
 146
 147static struct kmem_cache * ext2_inode_cachep;
 148
 149static struct inode *ext2_alloc_inode(struct super_block *sb)
 150{
 151        struct ext2_inode_info *ei;
 152        ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 153        if (!ei)
 154                return NULL;
 155        ei->i_block_alloc_info = NULL;
 156        ei->vfs_inode.i_version = 1;
 157        return &ei->vfs_inode;
 158}
 159
 160static void ext2_destroy_inode(struct inode *inode)
 161{
 162        kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 163}
 164
 165static void init_once(void *foo)
 166{
 167        struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 168
 169        rwlock_init(&ei->i_meta_lock);
 170#ifdef CONFIG_EXT2_FS_XATTR
 171        init_rwsem(&ei->xattr_sem);
 172#endif
 173        mutex_init(&ei->truncate_mutex);
 174        inode_init_once(&ei->vfs_inode);
 175}
 176
 177static int init_inodecache(void)
 178{
 179        ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 180                                             sizeof(struct ext2_inode_info),
 181                                             0, (SLAB_RECLAIM_ACCOUNT|
 182                                                SLAB_MEM_SPREAD),
 183                                             init_once);
 184        if (ext2_inode_cachep == NULL)
 185                return -ENOMEM;
 186        return 0;
 187}
 188
 189static void destroy_inodecache(void)
 190{
 191        kmem_cache_destroy(ext2_inode_cachep);
 192}
 193
 194static void ext2_clear_inode(struct inode *inode)
 195{
 196        struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
 197        ext2_discard_reservation(inode);
 198        EXT2_I(inode)->i_block_alloc_info = NULL;
 199        if (unlikely(rsv))
 200                kfree(rsv);
 201}
 202
 203static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
 204{
 205        struct super_block *sb = vfs->mnt_sb;
 206        struct ext2_sb_info *sbi = EXT2_SB(sb);
 207        struct ext2_super_block *es = sbi->s_es;
 208        unsigned long def_mount_opts;
 209
 210        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 211
 212        if (sbi->s_sb_block != 1)
 213                seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 214        if (test_opt(sb, MINIX_DF))
 215                seq_puts(seq, ",minixdf");
 216        if (test_opt(sb, GRPID))
 217                seq_puts(seq, ",grpid");
 218        if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 219                seq_puts(seq, ",nogrpid");
 220        if (sbi->s_resuid != EXT2_DEF_RESUID ||
 221            le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 222                seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 223        }
 224        if (sbi->s_resgid != EXT2_DEF_RESGID ||
 225            le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 226                seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 227        }
 228        if (test_opt(sb, ERRORS_RO)) {
 229                int def_errors = le16_to_cpu(es->s_errors);
 230
 231                if (def_errors == EXT2_ERRORS_PANIC ||
 232                    def_errors == EXT2_ERRORS_CONTINUE) {
 233                        seq_puts(seq, ",errors=remount-ro");
 234                }
 235        }
 236        if (test_opt(sb, ERRORS_CONT))
 237                seq_puts(seq, ",errors=continue");
 238        if (test_opt(sb, ERRORS_PANIC))
 239                seq_puts(seq, ",errors=panic");
 240        if (test_opt(sb, NO_UID32))
 241                seq_puts(seq, ",nouid32");
 242        if (test_opt(sb, DEBUG))
 243                seq_puts(seq, ",debug");
 244        if (test_opt(sb, OLDALLOC))
 245                seq_puts(seq, ",oldalloc");
 246
 247#ifdef CONFIG_EXT2_FS_XATTR
 248        if (test_opt(sb, XATTR_USER))
 249                seq_puts(seq, ",user_xattr");
 250        if (!test_opt(sb, XATTR_USER) &&
 251            (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 252                seq_puts(seq, ",nouser_xattr");
 253        }
 254#endif
 255
 256#ifdef CONFIG_EXT2_FS_POSIX_ACL
 257        if (test_opt(sb, POSIX_ACL))
 258                seq_puts(seq, ",acl");
 259        if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 260                seq_puts(seq, ",noacl");
 261#endif
 262
 263        if (test_opt(sb, NOBH))
 264                seq_puts(seq, ",nobh");
 265
 266#if defined(CONFIG_QUOTA)
 267        if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 268                seq_puts(seq, ",usrquota");
 269
 270        if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 271                seq_puts(seq, ",grpquota");
 272#endif
 273
 274#if defined(CONFIG_EXT2_FS_XIP)
 275        if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 276                seq_puts(seq, ",xip");
 277#endif
 278
 279        if (!test_opt(sb, RESERVATION))
 280                seq_puts(seq, ",noreservation");
 281
 282        return 0;
 283}
 284
 285#ifdef CONFIG_QUOTA
 286static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 287static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 288#endif
 289
 290static const struct super_operations ext2_sops = {
 291        .alloc_inode    = ext2_alloc_inode,
 292        .destroy_inode  = ext2_destroy_inode,
 293        .write_inode    = ext2_write_inode,
 294        .delete_inode   = ext2_delete_inode,
 295        .put_super      = ext2_put_super,
 296        .write_super    = ext2_write_super,
 297        .sync_fs        = ext2_sync_fs,
 298        .statfs         = ext2_statfs,
 299        .remount_fs     = ext2_remount,
 300        .clear_inode    = ext2_clear_inode,
 301        .show_options   = ext2_show_options,
 302#ifdef CONFIG_QUOTA
 303        .quota_read     = ext2_quota_read,
 304        .quota_write    = ext2_quota_write,
 305#endif
 306};
 307
 308static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 309                u64 ino, u32 generation)
 310{
 311        struct inode *inode;
 312
 313        if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 314                return ERR_PTR(-ESTALE);
 315        if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 316                return ERR_PTR(-ESTALE);
 317
 318        /* iget isn't really right if the inode is currently unallocated!!
 319         * ext2_read_inode currently does appropriate checks, but
 320         * it might be "neater" to call ext2_get_inode first and check
 321         * if the inode is valid.....
 322         */
 323        inode = ext2_iget(sb, ino);
 324        if (IS_ERR(inode))
 325                return ERR_CAST(inode);
 326        if (generation && inode->i_generation != generation) {
 327                /* we didn't find the right inode.. */
 328                iput(inode);
 329                return ERR_PTR(-ESTALE);
 330        }
 331        return inode;
 332}
 333
 334static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 335                int fh_len, int fh_type)
 336{
 337        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 338                                    ext2_nfs_get_inode);
 339}
 340
 341static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 342                int fh_len, int fh_type)
 343{
 344        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 345                                    ext2_nfs_get_inode);
 346}
 347
 348/* Yes, most of these are left as NULL!!
 349 * A NULL value implies the default, which works with ext2-like file
 350 * systems, but can be improved upon.
 351 * Currently only get_parent is required.
 352 */
 353static const struct export_operations ext2_export_ops = {
 354        .fh_to_dentry = ext2_fh_to_dentry,
 355        .fh_to_parent = ext2_fh_to_parent,
 356        .get_parent = ext2_get_parent,
 357};
 358
 359static unsigned long get_sb_block(void **data)
 360{
 361        unsigned long   sb_block;
 362        char            *options = (char *) *data;
 363
 364        if (!options || strncmp(options, "sb=", 3) != 0)
 365                return 1;       /* Default location */
 366        options += 3;
 367        sb_block = simple_strtoul(options, &options, 0);
 368        if (*options && *options != ',') {
 369                printk("EXT2-fs: Invalid sb specification: %s\n",
 370                       (char *) *data);
 371                return 1;
 372        }
 373        if (*options == ',')
 374                options++;
 375        *data = (void *) options;
 376        return sb_block;
 377}
 378
 379enum {
 380        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 381        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 382        Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 383        Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 384        Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 385        Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 386};
 387
 388static const match_table_t tokens = {
 389        {Opt_bsd_df, "bsddf"},
 390        {Opt_minix_df, "minixdf"},
 391        {Opt_grpid, "grpid"},
 392        {Opt_grpid, "bsdgroups"},
 393        {Opt_nogrpid, "nogrpid"},
 394        {Opt_nogrpid, "sysvgroups"},
 395        {Opt_resgid, "resgid=%u"},
 396        {Opt_resuid, "resuid=%u"},
 397        {Opt_sb, "sb=%u"},
 398        {Opt_err_cont, "errors=continue"},
 399        {Opt_err_panic, "errors=panic"},
 400        {Opt_err_ro, "errors=remount-ro"},
 401        {Opt_nouid32, "nouid32"},
 402        {Opt_nocheck, "check=none"},
 403        {Opt_nocheck, "nocheck"},
 404        {Opt_debug, "debug"},
 405        {Opt_oldalloc, "oldalloc"},
 406        {Opt_orlov, "orlov"},
 407        {Opt_nobh, "nobh"},
 408        {Opt_user_xattr, "user_xattr"},
 409        {Opt_nouser_xattr, "nouser_xattr"},
 410        {Opt_acl, "acl"},
 411        {Opt_noacl, "noacl"},
 412        {Opt_xip, "xip"},
 413        {Opt_grpquota, "grpquota"},
 414        {Opt_ignore, "noquota"},
 415        {Opt_quota, "quota"},
 416        {Opt_usrquota, "usrquota"},
 417        {Opt_reservation, "reservation"},
 418        {Opt_noreservation, "noreservation"},
 419        {Opt_err, NULL}
 420};
 421
 422static int parse_options (char * options,
 423                          struct ext2_sb_info *sbi)
 424{
 425        char * p;
 426        substring_t args[MAX_OPT_ARGS];
 427        int option;
 428
 429        if (!options)
 430                return 1;
 431
 432        while ((p = strsep (&options, ",")) != NULL) {
 433                int token;
 434                if (!*p)
 435                        continue;
 436
 437                token = match_token(p, tokens, args);
 438                switch (token) {
 439                case Opt_bsd_df:
 440                        clear_opt (sbi->s_mount_opt, MINIX_DF);
 441                        break;
 442                case Opt_minix_df:
 443                        set_opt (sbi->s_mount_opt, MINIX_DF);
 444                        break;
 445                case Opt_grpid:
 446                        set_opt (sbi->s_mount_opt, GRPID);
 447                        break;
 448                case Opt_nogrpid:
 449                        clear_opt (sbi->s_mount_opt, GRPID);
 450                        break;
 451                case Opt_resuid:
 452                        if (match_int(&args[0], &option))
 453                                return 0;
 454                        sbi->s_resuid = option;
 455                        break;
 456                case Opt_resgid:
 457                        if (match_int(&args[0], &option))
 458                                return 0;
 459                        sbi->s_resgid = option;
 460                        break;
 461                case Opt_sb:
 462                        /* handled by get_sb_block() instead of here */
 463                        /* *sb_block = match_int(&args[0]); */
 464                        break;
 465                case Opt_err_panic:
 466                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 467                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 468                        set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 469                        break;
 470                case Opt_err_ro:
 471                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 472                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 473                        set_opt (sbi->s_mount_opt, ERRORS_RO);
 474                        break;
 475                case Opt_err_cont:
 476                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 477                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 478                        set_opt (sbi->s_mount_opt, ERRORS_CONT);
 479                        break;
 480                case Opt_nouid32:
 481                        set_opt (sbi->s_mount_opt, NO_UID32);
 482                        break;
 483                case Opt_nocheck:
 484                        clear_opt (sbi->s_mount_opt, CHECK);
 485                        break;
 486                case Opt_debug:
 487                        set_opt (sbi->s_mount_opt, DEBUG);
 488                        break;
 489                case Opt_oldalloc:
 490                        set_opt (sbi->s_mount_opt, OLDALLOC);
 491                        break;
 492                case Opt_orlov:
 493                        clear_opt (sbi->s_mount_opt, OLDALLOC);
 494                        break;
 495                case Opt_nobh:
 496                        set_opt (sbi->s_mount_opt, NOBH);
 497                        break;
 498#ifdef CONFIG_EXT2_FS_XATTR
 499                case Opt_user_xattr:
 500                        set_opt (sbi->s_mount_opt, XATTR_USER);
 501                        break;
 502                case Opt_nouser_xattr:
 503                        clear_opt (sbi->s_mount_opt, XATTR_USER);
 504                        break;
 505#else
 506                case Opt_user_xattr:
 507                case Opt_nouser_xattr:
 508                        printk("EXT2 (no)user_xattr options not supported\n");
 509                        break;
 510#endif
 511#ifdef CONFIG_EXT2_FS_POSIX_ACL
 512                case Opt_acl:
 513                        set_opt(sbi->s_mount_opt, POSIX_ACL);
 514                        break;
 515                case Opt_noacl:
 516                        clear_opt(sbi->s_mount_opt, POSIX_ACL);
 517                        break;
 518#else
 519                case Opt_acl:
 520                case Opt_noacl:
 521                        printk("EXT2 (no)acl options not supported\n");
 522                        break;
 523#endif
 524                case Opt_xip:
 525#ifdef CONFIG_EXT2_FS_XIP
 526                        set_opt (sbi->s_mount_opt, XIP);
 527#else
 528                        printk("EXT2 xip option not supported\n");
 529#endif
 530                        break;
 531
 532#if defined(CONFIG_QUOTA)
 533                case Opt_quota:
 534                case Opt_usrquota:
 535                        set_opt(sbi->s_mount_opt, USRQUOTA);
 536                        break;
 537
 538                case Opt_grpquota:
 539                        set_opt(sbi->s_mount_opt, GRPQUOTA);
 540                        break;
 541#else
 542                case Opt_quota:
 543                case Opt_usrquota:
 544                case Opt_grpquota:
 545                        printk(KERN_ERR
 546                                "EXT2-fs: quota operations not supported.\n");
 547
 548                        break;
 549#endif
 550
 551                case Opt_reservation:
 552                        set_opt(sbi->s_mount_opt, RESERVATION);
 553                        printk("reservations ON\n");
 554                        break;
 555                case Opt_noreservation:
 556                        clear_opt(sbi->s_mount_opt, RESERVATION);
 557                        printk("reservations OFF\n");
 558                        break;
 559                case Opt_ignore:
 560                        break;
 561                default:
 562                        return 0;
 563                }
 564        }
 565        return 1;
 566}
 567
 568static int ext2_setup_super (struct super_block * sb,
 569                              struct ext2_super_block * es,
 570                              int read_only)
 571{
 572        int res = 0;
 573        struct ext2_sb_info *sbi = EXT2_SB(sb);
 574
 575        if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 576                printk ("EXT2-fs warning: revision level too high, "
 577                        "forcing read-only mode\n");
 578                res = MS_RDONLY;
 579        }
 580        if (read_only)
 581                return res;
 582        if (!(sbi->s_mount_state & EXT2_VALID_FS))
 583                printk ("EXT2-fs warning: mounting unchecked fs, "
 584                        "running e2fsck is recommended\n");
 585        else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 586                printk ("EXT2-fs warning: mounting fs with errors, "
 587                        "running e2fsck is recommended\n");
 588        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 589                 le16_to_cpu(es->s_mnt_count) >=
 590                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 591                printk ("EXT2-fs warning: maximal mount count reached, "
 592                        "running e2fsck is recommended\n");
 593        else if (le32_to_cpu(es->s_checkinterval) &&
 594                (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 595                printk ("EXT2-fs warning: checktime reached, "
 596                        "running e2fsck is recommended\n");
 597        if (!le16_to_cpu(es->s_max_mnt_count))
 598                es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 599        le16_add_cpu(&es->s_mnt_count, 1);
 600        ext2_write_super(sb);
 601        if (test_opt (sb, DEBUG))
 602                printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
 603                        "bpg=%lu, ipg=%lu, mo=%04lx]\n",
 604                        EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 605                        sbi->s_frag_size,
 606                        sbi->s_groups_count,
 607                        EXT2_BLOCKS_PER_GROUP(sb),
 608                        EXT2_INODES_PER_GROUP(sb),
 609                        sbi->s_mount_opt);
 610        return res;
 611}
 612
 613static int ext2_check_descriptors(struct super_block *sb)
 614{
 615        int i;
 616        struct ext2_sb_info *sbi = EXT2_SB(sb);
 617
 618        ext2_debug ("Checking group descriptors");
 619
 620        for (i = 0; i < sbi->s_groups_count; i++) {
 621                struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 622                ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 623                ext2_fsblk_t last_block;
 624
 625                if (i == sbi->s_groups_count - 1)
 626                        last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 627                else
 628                        last_block = first_block +
 629                                (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 630
 631                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 632                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 633                {
 634                        ext2_error (sb, "ext2_check_descriptors",
 635                                    "Block bitmap for group %d"
 636                                    " not in group (block %lu)!",
 637                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 638                        return 0;
 639                }
 640                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 641                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 642                {
 643                        ext2_error (sb, "ext2_check_descriptors",
 644                                    "Inode bitmap for group %d"
 645                                    " not in group (block %lu)!",
 646                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 647                        return 0;
 648                }
 649                if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 650                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 651                    last_block)
 652                {
 653                        ext2_error (sb, "ext2_check_descriptors",
 654                                    "Inode table for group %d"
 655                                    " not in group (block %lu)!",
 656                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 657                        return 0;
 658                }
 659        }
 660        return 1;
 661}
 662
 663/*
 664 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 665 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 666 * We need to be 1 filesystem block less than the 2^32 sector limit.
 667 */
 668static loff_t ext2_max_size(int bits)
 669{
 670        loff_t res = EXT2_NDIR_BLOCKS;
 671        int meta_blocks;
 672        loff_t upper_limit;
 673
 674        /* This is calculated to be the largest file size for a
 675         * dense, file such that the total number of
 676         * sectors in the file, including data and all indirect blocks,
 677         * does not exceed 2^32 -1
 678         * __u32 i_blocks representing the total number of
 679         * 512 bytes blocks of the file
 680         */
 681        upper_limit = (1LL << 32) - 1;
 682
 683        /* total blocks in file system block size */
 684        upper_limit >>= (bits - 9);
 685
 686
 687        /* indirect blocks */
 688        meta_blocks = 1;
 689        /* double indirect blocks */
 690        meta_blocks += 1 + (1LL << (bits-2));
 691        /* tripple indirect blocks */
 692        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 693
 694        upper_limit -= meta_blocks;
 695        upper_limit <<= bits;
 696
 697        res += 1LL << (bits-2);
 698        res += 1LL << (2*(bits-2));
 699        res += 1LL << (3*(bits-2));
 700        res <<= bits;
 701        if (res > upper_limit)
 702                res = upper_limit;
 703
 704        if (res > MAX_LFS_FILESIZE)
 705                res = MAX_LFS_FILESIZE;
 706
 707        return res;
 708}
 709
 710static unsigned long descriptor_loc(struct super_block *sb,
 711                                    unsigned long logic_sb_block,
 712                                    int nr)
 713{
 714        struct ext2_sb_info *sbi = EXT2_SB(sb);
 715        unsigned long bg, first_meta_bg;
 716        int has_super = 0;
 717        
 718        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 719
 720        if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 721            nr < first_meta_bg)
 722                return (logic_sb_block + nr + 1);
 723        bg = sbi->s_desc_per_block * nr;
 724        if (ext2_bg_has_super(sb, bg))
 725                has_super = 1;
 726
 727        return ext2_group_first_block_no(sb, bg) + has_super;
 728}
 729
 730static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 731{
 732        struct buffer_head * bh;
 733        struct ext2_sb_info * sbi;
 734        struct ext2_super_block * es;
 735        struct inode *root;
 736        unsigned long block;
 737        unsigned long sb_block = get_sb_block(&data);
 738        unsigned long logic_sb_block;
 739        unsigned long offset = 0;
 740        unsigned long def_mount_opts;
 741        long ret = -EINVAL;
 742        int blocksize = BLOCK_SIZE;
 743        int db_count;
 744        int i, j;
 745        __le32 features;
 746        int err;
 747
 748        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 749        if (!sbi)
 750                return -ENOMEM;
 751
 752        sbi->s_blockgroup_lock =
 753                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 754        if (!sbi->s_blockgroup_lock) {
 755                kfree(sbi);
 756                return -ENOMEM;
 757        }
 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->s_blockgroup_lock);
1088        kfree(sbi);
1089        return ret;
1090}
1091
1092static void ext2_commit_super (struct super_block * sb,
1093                               struct ext2_super_block * es)
1094{
1095        es->s_wtime = cpu_to_le32(get_seconds());
1096        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1097        sb->s_dirt = 0;
1098}
1099
1100static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1101{
1102        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1103        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1104        es->s_wtime = cpu_to_le32(get_seconds());
1105        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1106        sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1107        sb->s_dirt = 0;
1108}
1109
1110/*
1111 * In the second extended file system, it is not necessary to
1112 * write the super block since we use a mapping of the
1113 * disk super block in a buffer.
1114 *
1115 * However, this function is still used to set the fs valid
1116 * flags to 0.  We need to set this flag to 0 since the fs
1117 * may have been checked while mounted and e2fsck may have
1118 * set s_state to EXT2_VALID_FS after some corrections.
1119 */
1120
1121static int ext2_sync_fs(struct super_block *sb, int wait)
1122{
1123        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1124
1125        lock_kernel();
1126        if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1127                ext2_debug("setting valid to 0\n");
1128                es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1129                es->s_free_blocks_count =
1130                        cpu_to_le32(ext2_count_free_blocks(sb));
1131                es->s_free_inodes_count =
1132                        cpu_to_le32(ext2_count_free_inodes(sb));
1133                es->s_mtime = cpu_to_le32(get_seconds());
1134                ext2_sync_super(sb, es);
1135        } else {
1136                ext2_commit_super(sb, es);
1137        }
1138        sb->s_dirt = 0;
1139        unlock_kernel();
1140
1141        return 0;
1142}
1143
1144
1145void ext2_write_super(struct super_block *sb)
1146{
1147        if (!(sb->s_flags & MS_RDONLY))
1148                ext2_sync_fs(sb, 1);
1149        else
1150                sb->s_dirt = 0;
1151}
1152
1153static int ext2_remount (struct super_block * sb, int * flags, char * data)
1154{
1155        struct ext2_sb_info * sbi = EXT2_SB(sb);
1156        struct ext2_super_block * es;
1157        unsigned long old_mount_opt = sbi->s_mount_opt;
1158        struct ext2_mount_options old_opts;
1159        unsigned long old_sb_flags;
1160        int err;
1161
1162        lock_kernel();
1163
1164        /* Store the old options */
1165        old_sb_flags = sb->s_flags;
1166        old_opts.s_mount_opt = sbi->s_mount_opt;
1167        old_opts.s_resuid = sbi->s_resuid;
1168        old_opts.s_resgid = sbi->s_resgid;
1169
1170        /*
1171         * Allow the "check" option to be passed as a remount option.
1172         */
1173        if (!parse_options (data, sbi)) {
1174                err = -EINVAL;
1175                goto restore_opts;
1176        }
1177
1178        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1179                ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1180
1181        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1182                                    EXT2_MOUNT_XIP if not */
1183
1184        if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1185                printk("XIP: Unsupported blocksize\n");
1186                err = -EINVAL;
1187                goto restore_opts;
1188        }
1189
1190        es = sbi->s_es;
1191        if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1192            (old_mount_opt & EXT2_MOUNT_XIP)) &&
1193            invalidate_inodes(sb)) {
1194                ext2_warning(sb, __func__, "refusing change of xip flag "
1195                             "with busy inodes while remounting");
1196                sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1197                sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1198        }
1199        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1200                unlock_kernel();
1201                return 0;
1202        }
1203        if (*flags & MS_RDONLY) {
1204                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1205                    !(sbi->s_mount_state & EXT2_VALID_FS)) {
1206                        unlock_kernel();
1207                        return 0;
1208                }
1209                /*
1210                 * OK, we are remounting a valid rw partition rdonly, so set
1211                 * the rdonly flag and then mark the partition as valid again.
1212                 */
1213                es->s_state = cpu_to_le16(sbi->s_mount_state);
1214                es->s_mtime = cpu_to_le32(get_seconds());
1215        } else {
1216                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1217                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
1218                if (ret) {
1219                        printk("EXT2-fs: %s: couldn't remount RDWR because of "
1220                               "unsupported optional features (%x).\n",
1221                               sb->s_id, le32_to_cpu(ret));
1222                        err = -EROFS;
1223                        goto restore_opts;
1224                }
1225                /*
1226                 * Mounting a RDONLY partition read-write, so reread and
1227                 * store the current valid flag.  (It may have been changed
1228                 * by e2fsck since we originally mounted the partition.)
1229                 */
1230                sbi->s_mount_state = le16_to_cpu(es->s_state);
1231                if (!ext2_setup_super (sb, es, 0))
1232                        sb->s_flags &= ~MS_RDONLY;
1233        }
1234        ext2_sync_super(sb, es);
1235        unlock_kernel();
1236        return 0;
1237restore_opts:
1238        sbi->s_mount_opt = old_opts.s_mount_opt;
1239        sbi->s_resuid = old_opts.s_resuid;
1240        sbi->s_resgid = old_opts.s_resgid;
1241        sb->s_flags = old_sb_flags;
1242        unlock_kernel();
1243        return err;
1244}
1245
1246static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1247{
1248        struct super_block *sb = dentry->d_sb;
1249        struct ext2_sb_info *sbi = EXT2_SB(sb);
1250        struct ext2_super_block *es = sbi->s_es;
1251        u64 fsid;
1252
1253        if (test_opt (sb, MINIX_DF))
1254                sbi->s_overhead_last = 0;
1255        else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1256                unsigned long i, overhead = 0;
1257                smp_rmb();
1258
1259                /*
1260                 * Compute the overhead (FS structures). This is constant
1261                 * for a given filesystem unless the number of block groups
1262                 * changes so we cache the previous value until it does.
1263                 */
1264
1265                /*
1266                 * All of the blocks before first_data_block are
1267                 * overhead
1268                 */
1269                overhead = le32_to_cpu(es->s_first_data_block);
1270
1271                /*
1272                 * Add the overhead attributed to the superblock and
1273                 * block group descriptors.  If the sparse superblocks
1274                 * feature is turned on, then not all groups have this.
1275                 */
1276                for (i = 0; i < sbi->s_groups_count; i++)
1277                        overhead += ext2_bg_has_super(sb, i) +
1278                                ext2_bg_num_gdb(sb, i);
1279
1280                /*
1281                 * Every block group has an inode bitmap, a block
1282                 * bitmap, and an inode table.
1283                 */
1284                overhead += (sbi->s_groups_count *
1285                             (2 + sbi->s_itb_per_group));
1286                sbi->s_overhead_last = overhead;
1287                smp_wmb();
1288                sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1289        }
1290
1291        buf->f_type = EXT2_SUPER_MAGIC;
1292        buf->f_bsize = sb->s_blocksize;
1293        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1294        buf->f_bfree = ext2_count_free_blocks(sb);
1295        es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1296        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1297        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1298                buf->f_bavail = 0;
1299        buf->f_files = le32_to_cpu(es->s_inodes_count);
1300        buf->f_ffree = ext2_count_free_inodes(sb);
1301        es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1302        buf->f_namelen = EXT2_NAME_LEN;
1303        fsid = le64_to_cpup((void *)es->s_uuid) ^
1304               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1305        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1306        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1307        return 0;
1308}
1309
1310static int ext2_get_sb(struct file_system_type *fs_type,
1311        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1312{
1313        return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1314}
1315
1316#ifdef CONFIG_QUOTA
1317
1318/* Read data from quotafile - avoid pagecache and such because we cannot afford
1319 * acquiring the locks... As quota files are never truncated and quota code
1320 * itself serializes the operations (and noone else should touch the files)
1321 * we don't have to be afraid of races */
1322static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1323                               size_t len, loff_t off)
1324{
1325        struct inode *inode = sb_dqopt(sb)->files[type];
1326        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1327        int err = 0;
1328        int offset = off & (sb->s_blocksize - 1);
1329        int tocopy;
1330        size_t toread;
1331        struct buffer_head tmp_bh;
1332        struct buffer_head *bh;
1333        loff_t i_size = i_size_read(inode);
1334
1335        if (off > i_size)
1336                return 0;
1337        if (off+len > i_size)
1338                len = i_size-off;
1339        toread = len;
1340        while (toread > 0) {
1341                tocopy = sb->s_blocksize - offset < toread ?
1342                                sb->s_blocksize - offset : toread;
1343
1344                tmp_bh.b_state = 0;
1345                tmp_bh.b_size = sb->s_blocksize;
1346                err = ext2_get_block(inode, blk, &tmp_bh, 0);
1347                if (err < 0)
1348                        return err;
1349                if (!buffer_mapped(&tmp_bh))    /* A hole? */
1350                        memset(data, 0, tocopy);
1351                else {
1352                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1353                        if (!bh)
1354                                return -EIO;
1355                        memcpy(data, bh->b_data+offset, tocopy);
1356                        brelse(bh);
1357                }
1358                offset = 0;
1359                toread -= tocopy;
1360                data += tocopy;
1361                blk++;
1362        }
1363        return len;
1364}
1365
1366/* Write to quotafile */
1367static ssize_t ext2_quota_write(struct super_block *sb, int type,
1368                                const char *data, size_t len, loff_t off)
1369{
1370        struct inode *inode = sb_dqopt(sb)->files[type];
1371        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1372        int err = 0;
1373        int offset = off & (sb->s_blocksize - 1);
1374        int tocopy;
1375        size_t towrite = len;
1376        struct buffer_head tmp_bh;
1377        struct buffer_head *bh;
1378
1379        mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1380        while (towrite > 0) {
1381                tocopy = sb->s_blocksize - offset < towrite ?
1382                                sb->s_blocksize - offset : towrite;
1383
1384                tmp_bh.b_state = 0;
1385                err = ext2_get_block(inode, blk, &tmp_bh, 1);
1386                if (err < 0)
1387                        goto out;
1388                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1389                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1390                else
1391                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
1392                if (!bh) {
1393                        err = -EIO;
1394                        goto out;
1395                }
1396                lock_buffer(bh);
1397                memcpy(bh->b_data+offset, data, tocopy);
1398                flush_dcache_page(bh->b_page);
1399                set_buffer_uptodate(bh);
1400                mark_buffer_dirty(bh);
1401                unlock_buffer(bh);
1402                brelse(bh);
1403                offset = 0;
1404                towrite -= tocopy;
1405                data += tocopy;
1406                blk++;
1407        }
1408out:
1409        if (len == towrite) {
1410                mutex_unlock(&inode->i_mutex);
1411                return err;
1412        }
1413        if (inode->i_size < off+len-towrite)
1414                i_size_write(inode, off+len-towrite);
1415        inode->i_version++;
1416        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1417        mark_inode_dirty(inode);
1418        mutex_unlock(&inode->i_mutex);
1419        return len - towrite;
1420}
1421
1422#endif
1423
1424static struct file_system_type ext2_fs_type = {
1425        .owner          = THIS_MODULE,
1426        .name           = "ext2",
1427        .get_sb         = ext2_get_sb,
1428        .kill_sb        = kill_block_super,
1429        .fs_flags       = FS_REQUIRES_DEV,
1430};
1431
1432static int __init init_ext2_fs(void)
1433{
1434        int err = init_ext2_xattr();
1435        if (err)
1436                return err;
1437        err = init_inodecache();
1438        if (err)
1439                goto out1;
1440        err = register_filesystem(&ext2_fs_type);
1441        if (err)
1442                goto out;
1443        return 0;
1444out:
1445        destroy_inodecache();
1446out1:
1447        exit_ext2_xattr();
1448        return err;
1449}
1450
1451static void __exit exit_ext2_fs(void)
1452{
1453        unregister_filesystem(&ext2_fs_type);
1454        destroy_inodecache();
1455        exit_ext2_xattr();
1456}
1457
1458module_init(init_ext2_fs)
1459module_exit(exit_ext2_fs)
1460