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 =
  55                        cpu_to_le16(le16_to_cpu(es->s_state) | EXT2_ERROR_FS);
  56                ext2_sync_super(sb, es);
  57        }
  58
  59        va_start(args, fmt);
  60        printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
  61        vprintk(fmt, args);
  62        printk("\n");
  63        va_end(args);
  64
  65        if (test_opt(sb, ERRORS_PANIC))
  66                panic("EXT2-fs panic from previous error\n");
  67        if (test_opt(sb, ERRORS_RO)) {
  68                printk("Remounting filesystem read-only\n");
  69                sb->s_flags |= MS_RDONLY;
  70        }
  71}
  72
  73void ext2_warning (struct super_block * sb, const char * function,
  74                   const char * fmt, ...)
  75{
  76        va_list args;
  77
  78        va_start(args, fmt);
  79        printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
  80               sb->s_id, function);
  81        vprintk(fmt, args);
  82        printk("\n");
  83        va_end(args);
  84}
  85
  86void ext2_update_dynamic_rev(struct super_block *sb)
  87{
  88        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
  89
  90        if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
  91                return;
  92
  93        ext2_warning(sb, __FUNCTION__,
  94                     "updating to rev %d because of new feature flag, "
  95                     "running e2fsck is recommended",
  96                     EXT2_DYNAMIC_REV);
  97
  98        es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
  99        es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 100        es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 101        /* leave es->s_feature_*compat flags alone */
 102        /* es->s_uuid will be set by e2fsck if empty */
 103
 104        /*
 105         * The rest of the superblock fields should be zero, and if not it
 106         * means they are likely already in use, so leave them alone.  We
 107         * can leave it up to e2fsck to clean up any inconsistencies there.
 108         */
 109}
 110
 111static void ext2_put_super (struct super_block * sb)
 112{
 113        int db_count;
 114        int i;
 115        struct ext2_sb_info *sbi = EXT2_SB(sb);
 116
 117        ext2_xattr_put_super(sb);
 118        if (!(sb->s_flags & MS_RDONLY)) {
 119                struct ext2_super_block *es = sbi->s_es;
 120
 121                es->s_state = cpu_to_le16(sbi->s_mount_state);
 122                ext2_sync_super(sb, es);
 123        }
 124        db_count = sbi->s_gdb_count;
 125        for (i = 0; i < db_count; i++)
 126                if (sbi->s_group_desc[i])
 127                        brelse (sbi->s_group_desc[i]);
 128        kfree(sbi->s_group_desc);
 129        kfree(sbi->s_debts);
 130        percpu_counter_destroy(&sbi->s_freeblocks_counter);
 131        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 132        percpu_counter_destroy(&sbi->s_dirs_counter);
 133        brelse (sbi->s_sbh);
 134        sb->s_fs_info = NULL;
 135        kfree(sbi);
 136
 137        return;
 138}
 139
 140static struct kmem_cache * ext2_inode_cachep;
 141
 142static struct inode *ext2_alloc_inode(struct super_block *sb)
 143{
 144        struct ext2_inode_info *ei;
 145        ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 146        if (!ei)
 147                return NULL;
 148#ifdef CONFIG_EXT2_FS_POSIX_ACL
 149        ei->i_acl = EXT2_ACL_NOT_CACHED;
 150        ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 151#endif
 152        ei->i_block_alloc_info = NULL;
 153        ei->vfs_inode.i_version = 1;
 154        return &ei->vfs_inode;
 155}
 156
 157static void ext2_destroy_inode(struct inode *inode)
 158{
 159        kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 160}
 161
 162static void init_once(struct kmem_cache * cachep, void *foo)
 163{
 164        struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 165
 166        rwlock_init(&ei->i_meta_lock);
 167#ifdef CONFIG_EXT2_FS_XATTR
 168        init_rwsem(&ei->xattr_sem);
 169#endif
 170        mutex_init(&ei->truncate_mutex);
 171        inode_init_once(&ei->vfs_inode);
 172}
 173
 174static int init_inodecache(void)
 175{
 176        ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 177                                             sizeof(struct ext2_inode_info),
 178                                             0, (SLAB_RECLAIM_ACCOUNT|
 179                                                SLAB_MEM_SPREAD),
 180                                             init_once);
 181        if (ext2_inode_cachep == NULL)
 182                return -ENOMEM;
 183        return 0;
 184}
 185
 186static void destroy_inodecache(void)
 187{
 188        kmem_cache_destroy(ext2_inode_cachep);
 189}
 190
 191static void ext2_clear_inode(struct inode *inode)
 192{
 193        struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
 194#ifdef CONFIG_EXT2_FS_POSIX_ACL
 195        struct ext2_inode_info *ei = EXT2_I(inode);
 196
 197        if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
 198                posix_acl_release(ei->i_acl);
 199                ei->i_acl = EXT2_ACL_NOT_CACHED;
 200        }
 201        if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
 202                posix_acl_release(ei->i_default_acl);
 203                ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 204        }
 205#endif
 206        ext2_discard_reservation(inode);
 207        EXT2_I(inode)->i_block_alloc_info = NULL;
 208        if (unlikely(rsv))
 209                kfree(rsv);
 210}
 211
 212static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
 213{
 214        struct super_block *sb = vfs->mnt_sb;
 215        struct ext2_sb_info *sbi = EXT2_SB(sb);
 216        struct ext2_super_block *es = sbi->s_es;
 217        unsigned long def_mount_opts;
 218
 219        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 220
 221        if (sbi->s_sb_block != 1)
 222                seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 223        if (test_opt(sb, MINIX_DF))
 224                seq_puts(seq, ",minixdf");
 225        if (test_opt(sb, GRPID))
 226                seq_puts(seq, ",grpid");
 227        if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 228                seq_puts(seq, ",nogrpid");
 229        if (sbi->s_resuid != EXT2_DEF_RESUID ||
 230            le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 231                seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 232        }
 233        if (sbi->s_resgid != EXT2_DEF_RESGID ||
 234            le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 235                seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 236        }
 237        if (test_opt(sb, ERRORS_CONT)) {
 238                int def_errors = le16_to_cpu(es->s_errors);
 239
 240                if (def_errors == EXT2_ERRORS_PANIC ||
 241                    def_errors == EXT2_ERRORS_RO) {
 242                        seq_puts(seq, ",errors=continue");
 243                }
 244        }
 245        if (test_opt(sb, ERRORS_RO))
 246                seq_puts(seq, ",errors=remount-ro");
 247        if (test_opt(sb, ERRORS_PANIC))
 248                seq_puts(seq, ",errors=panic");
 249        if (test_opt(sb, NO_UID32))
 250                seq_puts(seq, ",nouid32");
 251        if (test_opt(sb, DEBUG))
 252                seq_puts(seq, ",debug");
 253        if (test_opt(sb, OLDALLOC))
 254                seq_puts(seq, ",oldalloc");
 255
 256#ifdef CONFIG_EXT2_FS_XATTR
 257        if (test_opt(sb, XATTR_USER))
 258                seq_puts(seq, ",user_xattr");
 259        if (!test_opt(sb, XATTR_USER) &&
 260            (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 261                seq_puts(seq, ",nouser_xattr");
 262        }
 263#endif
 264
 265#ifdef CONFIG_EXT2_FS_POSIX_ACL
 266        if (test_opt(sb, POSIX_ACL))
 267                seq_puts(seq, ",acl");
 268        if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 269                seq_puts(seq, ",noacl");
 270#endif
 271
 272        if (test_opt(sb, NOBH))
 273                seq_puts(seq, ",nobh");
 274
 275#if defined(CONFIG_QUOTA)
 276        if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 277                seq_puts(seq, ",usrquota");
 278
 279        if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 280                seq_puts(seq, ",grpquota");
 281#endif
 282
 283#if defined(CONFIG_EXT2_FS_XIP)
 284        if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 285                seq_puts(seq, ",xip");
 286#endif
 287
 288        return 0;
 289}
 290
 291#ifdef CONFIG_QUOTA
 292static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 293static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 294#endif
 295
 296static const struct super_operations ext2_sops = {
 297        .alloc_inode    = ext2_alloc_inode,
 298        .destroy_inode  = ext2_destroy_inode,
 299        .read_inode     = ext2_read_inode,
 300        .write_inode    = ext2_write_inode,
 301        .delete_inode   = ext2_delete_inode,
 302        .put_super      = ext2_put_super,
 303        .write_super    = ext2_write_super,
 304        .statfs         = ext2_statfs,
 305        .remount_fs     = ext2_remount,
 306        .clear_inode    = ext2_clear_inode,
 307        .show_options   = ext2_show_options,
 308#ifdef CONFIG_QUOTA
 309        .quota_read     = ext2_quota_read,
 310        .quota_write    = ext2_quota_write,
 311#endif
 312};
 313
 314static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 315                u64 ino, u32 generation)
 316{
 317        struct inode *inode;
 318
 319        if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 320                return ERR_PTR(-ESTALE);
 321        if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 322                return ERR_PTR(-ESTALE);
 323
 324        /* iget isn't really right if the inode is currently unallocated!!
 325         * ext2_read_inode currently does appropriate checks, but
 326         * it might be "neater" to call ext2_get_inode first and check
 327         * if the inode is valid.....
 328         */
 329        inode = iget(sb, ino);
 330        if (inode == NULL)
 331                return ERR_PTR(-ENOMEM);
 332        if (is_bad_inode(inode) ||
 333            (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        es->s_mnt_count=cpu_to_le16(le16_to_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        int desc_block = 0;
 624        struct ext2_sb_info *sbi = EXT2_SB(sb);
 625        unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
 626        unsigned long last_block;
 627        struct ext2_group_desc * gdp = NULL;
 628
 629        ext2_debug ("Checking group descriptors");
 630
 631        for (i = 0; i < sbi->s_groups_count; i++)
 632        {
 633                if (i == sbi->s_groups_count - 1)
 634                        last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 635                else
 636                        last_block = first_block +
 637                                (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 638
 639                if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
 640                        gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
 641                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 642                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 643                {
 644                        ext2_error (sb, "ext2_check_descriptors",
 645                                    "Block bitmap for group %d"
 646                                    " not in group (block %lu)!",
 647                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 648                        return 0;
 649                }
 650                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 651                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 652                {
 653                        ext2_error (sb, "ext2_check_descriptors",
 654                                    "Inode bitmap for group %d"
 655                                    " not in group (block %lu)!",
 656                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 657                        return 0;
 658                }
 659                if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 660                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 661                    last_block)
 662                {
 663                        ext2_error (sb, "ext2_check_descriptors",
 664                                    "Inode table for group %d"
 665                                    " not in group (block %lu)!",
 666                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 667                        return 0;
 668                }
 669                first_block += EXT2_BLOCKS_PER_GROUP(sb);
 670                gdp++;
 671        }
 672        return 1;
 673}
 674
 675/*
 676 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 677 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 678 * We need to be 1 filesystem block less than the 2^32 sector limit.
 679 */
 680static loff_t ext2_max_size(int bits)
 681{
 682        loff_t res = EXT2_NDIR_BLOCKS;
 683        /* This constant is calculated to be the largest file size for a
 684         * dense, 4k-blocksize file such that the total number of
 685         * sectors in the file, including data and all indirect blocks,
 686         * does not exceed 2^32. */
 687        const loff_t upper_limit = 0x1ff7fffd000LL;
 688
 689        res += 1LL << (bits-2);
 690        res += 1LL << (2*(bits-2));
 691        res += 1LL << (3*(bits-2));
 692        res <<= bits;
 693        if (res > upper_limit)
 694                res = upper_limit;
 695        return res;
 696}
 697
 698static unsigned long descriptor_loc(struct super_block *sb,
 699                                    unsigned long logic_sb_block,
 700                                    int nr)
 701{
 702        struct ext2_sb_info *sbi = EXT2_SB(sb);
 703        unsigned long bg, first_data_block, first_meta_bg;
 704        int has_super = 0;
 705        
 706        first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block);
 707        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 708
 709        if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 710            nr < first_meta_bg)
 711                return (logic_sb_block + nr + 1);
 712        bg = sbi->s_desc_per_block * nr;
 713        if (ext2_bg_has_super(sb, bg))
 714                has_super = 1;
 715        return (first_data_block + has_super + (bg * sbi->s_blocks_per_group));
 716}
 717
 718static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 719{
 720        struct buffer_head * bh;
 721        struct ext2_sb_info * sbi;
 722        struct ext2_super_block * es;
 723        struct inode *root;
 724        unsigned long block;
 725        unsigned long sb_block = get_sb_block(&data);
 726        unsigned long logic_sb_block;
 727        unsigned long offset = 0;
 728        unsigned long def_mount_opts;
 729        int blocksize = BLOCK_SIZE;
 730        int db_count;
 731        int i, j;
 732        __le32 features;
 733        int err;
 734
 735        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 736        if (!sbi)
 737                return -ENOMEM;
 738        sb->s_fs_info = sbi;
 739        sbi->s_sb_block = sb_block;
 740
 741        /*
 742         * See what the current blocksize for the device is, and
 743         * use that as the blocksize.  Otherwise (or if the blocksize
 744         * is smaller than the default) use the default.
 745         * This is important for devices that have a hardware
 746         * sectorsize that is larger than the default.
 747         */
 748        blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 749        if (!blocksize) {
 750                printk ("EXT2-fs: unable to set blocksize\n");
 751                goto failed_sbi;
 752        }
 753
 754        /*
 755         * If the superblock doesn't start on a hardware sector boundary,
 756         * calculate the offset.  
 757         */
 758        if (blocksize != BLOCK_SIZE) {
 759                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 760                offset = (sb_block*BLOCK_SIZE) % blocksize;
 761        } else {
 762                logic_sb_block = sb_block;
 763        }
 764
 765        if (!(bh = sb_bread(sb, logic_sb_block))) {
 766                printk ("EXT2-fs: unable to read superblock\n");
 767                goto failed_sbi;
 768        }
 769        /*
 770         * Note: s_es must be initialized as soon as possible because
 771         *       some ext2 macro-instructions depend on its value
 772         */
 773        es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 774        sbi->s_es = es;
 775        sb->s_magic = le16_to_cpu(es->s_magic);
 776
 777        if (sb->s_magic != EXT2_SUPER_MAGIC)
 778                goto cantfind_ext2;
 779
 780        /* Set defaults before we parse the mount options */
 781        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 782        if (def_mount_opts & EXT2_DEFM_DEBUG)
 783                set_opt(sbi->s_mount_opt, DEBUG);
 784        if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 785                set_opt(sbi->s_mount_opt, GRPID);
 786        if (def_mount_opts & EXT2_DEFM_UID16)
 787                set_opt(sbi->s_mount_opt, NO_UID32);
 788#ifdef CONFIG_EXT2_FS_XATTR
 789        if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 790                set_opt(sbi->s_mount_opt, XATTR_USER);
 791#endif
 792#ifdef CONFIG_EXT2_FS_POSIX_ACL
 793        if (def_mount_opts & EXT2_DEFM_ACL)
 794                set_opt(sbi->s_mount_opt, POSIX_ACL);
 795#endif
 796        
 797        if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 798                set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 799        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_RO)
 800                set_opt(sbi->s_mount_opt, ERRORS_RO);
 801        else
 802                set_opt(sbi->s_mount_opt, ERRORS_CONT);
 803
 804        sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 805        sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 806        
 807        set_opt(sbi->s_mount_opt, RESERVATION);
 808
 809        if (!parse_options ((char *) data, sbi))
 810                goto failed_mount;
 811
 812        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 813                ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 814                 MS_POSIXACL : 0);
 815
 816        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 817                                    EXT2_MOUNT_XIP if not */
 818
 819        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 820            (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 821             EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 822             EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 823                printk("EXT2-fs warning: feature flags set on rev 0 fs, "
 824                       "running e2fsck is recommended\n");
 825        /*
 826         * Check feature flags regardless of the revision level, since we
 827         * previously didn't change the revision level when setting the flags,
 828         * so there is a chance incompat flags are set on a rev 0 filesystem.
 829         */
 830        features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 831        if (features) {
 832                printk("EXT2-fs: %s: couldn't mount because of "
 833                       "unsupported optional features (%x).\n",
 834                       sb->s_id, le32_to_cpu(features));
 835                goto failed_mount;
 836        }
 837        if (!(sb->s_flags & MS_RDONLY) &&
 838            (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 839                printk("EXT2-fs: %s: couldn't mount RDWR because of "
 840                       "unsupported optional features (%x).\n",
 841                       sb->s_id, le32_to_cpu(features));
 842                goto failed_mount;
 843        }
 844
 845        blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 846
 847        if ((ext2_use_xip(sb)) && ((blocksize != PAGE_SIZE) ||
 848                                  (sb->s_blocksize != blocksize))) {
 849                if (!silent)
 850                        printk("XIP: Unsupported blocksize\n");
 851                goto failed_mount;
 852        }
 853
 854        /* If the blocksize doesn't match, re-read the thing.. */
 855        if (sb->s_blocksize != blocksize) {
 856                brelse(bh);
 857
 858                if (!sb_set_blocksize(sb, blocksize)) {
 859                        printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
 860                        goto failed_sbi;
 861                }
 862
 863                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 864                offset = (sb_block*BLOCK_SIZE) % blocksize;
 865                bh = sb_bread(sb, logic_sb_block);
 866                if(!bh) {
 867                        printk("EXT2-fs: Couldn't read superblock on "
 868                               "2nd try.\n");
 869                        goto failed_sbi;
 870                }
 871                es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 872                sbi->s_es = es;
 873                if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 874                        printk ("EXT2-fs: Magic mismatch, very weird !\n");
 875                        goto failed_mount;
 876                }
 877        }
 878
 879        sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 880
 881        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 882                sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 883                sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 884        } else {
 885                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 886                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 887                if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 888                    !is_power_of_2(sbi->s_inode_size) ||
 889                    (sbi->s_inode_size > blocksize)) {
 890                        printk ("EXT2-fs: unsupported inode size: %d\n",
 891                                sbi->s_inode_size);
 892                        goto failed_mount;
 893                }
 894        }
 895
 896        sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 897                                   le32_to_cpu(es->s_log_frag_size);
 898        if (sbi->s_frag_size == 0)
 899                goto cantfind_ext2;
 900        sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 901
 902        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 903        sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 904        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 905
 906        if (EXT2_INODE_SIZE(sb) == 0)
 907                goto cantfind_ext2;
 908        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 909        if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 910                goto cantfind_ext2;
 911        sbi->s_itb_per_group = sbi->s_inodes_per_group /
 912                                        sbi->s_inodes_per_block;
 913        sbi->s_desc_per_block = sb->s_blocksize /
 914                                        sizeof (struct ext2_group_desc);
 915        sbi->s_sbh = bh;
 916        sbi->s_mount_state = le16_to_cpu(es->s_state);
 917        sbi->s_addr_per_block_bits =
 918                ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 919        sbi->s_desc_per_block_bits =
 920                ilog2 (EXT2_DESC_PER_BLOCK(sb));
 921
 922        if (sb->s_magic != EXT2_SUPER_MAGIC)
 923                goto cantfind_ext2;
 924
 925        if (sb->s_blocksize != bh->b_size) {
 926                if (!silent)
 927                        printk ("VFS: Unsupported blocksize on dev "
 928                                "%s.\n", sb->s_id);
 929                goto failed_mount;
 930        }
 931
 932        if (sb->s_blocksize != sbi->s_frag_size) {
 933                printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
 934                        sbi->s_frag_size, sb->s_blocksize);
 935                goto failed_mount;
 936        }
 937
 938        if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 939                printk ("EXT2-fs: #blocks per group too big: %lu\n",
 940                        sbi->s_blocks_per_group);
 941                goto failed_mount;
 942        }
 943        if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 944                printk ("EXT2-fs: #fragments per group too big: %lu\n",
 945                        sbi->s_frags_per_group);
 946                goto failed_mount;
 947        }
 948        if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 949                printk ("EXT2-fs: #inodes per group too big: %lu\n",
 950                        sbi->s_inodes_per_group);
 951                goto failed_mount;
 952        }
 953
 954        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 955                goto cantfind_ext2;
 956        sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
 957                                le32_to_cpu(es->s_first_data_block) - 1)
 958                                        / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
 959        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 960                   EXT2_DESC_PER_BLOCK(sb);
 961        sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
 962        if (sbi->s_group_desc == NULL) {
 963                printk ("EXT2-fs: not enough memory\n");
 964                goto failed_mount;
 965        }
 966        bgl_lock_init(&sbi->s_blockgroup_lock);
 967        sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
 968        if (!sbi->s_debts) {
 969                printk ("EXT2-fs: not enough memory\n");
 970                goto failed_mount_group_desc;
 971        }
 972        for (i = 0; i < db_count; i++) {
 973                block = descriptor_loc(sb, logic_sb_block, i);
 974                sbi->s_group_desc[i] = sb_bread(sb, block);
 975                if (!sbi->s_group_desc[i]) {
 976                        for (j = 0; j < i; j++)
 977                                brelse (sbi->s_group_desc[j]);
 978                        printk ("EXT2-fs: unable to read group descriptors\n");
 979                        goto failed_mount_group_desc;
 980                }
 981        }
 982        if (!ext2_check_descriptors (sb)) {
 983                printk ("EXT2-fs: group descriptors corrupted!\n");
 984                goto failed_mount2;
 985        }
 986        sbi->s_gdb_count = db_count;
 987        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 988        spin_lock_init(&sbi->s_next_gen_lock);
 989
 990        /* per fileystem reservation list head & lock */
 991        spin_lock_init(&sbi->s_rsv_window_lock);
 992        sbi->s_rsv_window_root = RB_ROOT;
 993        /*
 994         * Add a single, static dummy reservation to the start of the
 995         * reservation window list --- it gives us a placeholder for
 996         * append-at-start-of-list which makes the allocation logic
 997         * _much_ simpler.
 998         */
 999        sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1000        sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1001        sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1002        sbi->s_rsv_window_head.rsv_goal_size = 0;
1003        ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1004
1005        err = percpu_counter_init(&sbi->s_freeblocks_counter,
1006                                ext2_count_free_blocks(sb));
1007        if (!err) {
1008                err = percpu_counter_init(&sbi->s_freeinodes_counter,
1009                                ext2_count_free_inodes(sb));
1010        }
1011        if (!err) {
1012                err = percpu_counter_init(&sbi->s_dirs_counter,
1013                                ext2_count_dirs(sb));
1014        }
1015        if (err) {
1016                printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1017                goto failed_mount3;
1018        }
1019        /*
1020         * set up enough so that it can read an inode
1021         */
1022        sb->s_op = &ext2_sops;
1023        sb->s_export_op = &ext2_export_ops;
1024        sb->s_xattr = ext2_xattr_handlers;
1025        root = iget(sb, EXT2_ROOT_INO);
1026        sb->s_root = d_alloc_root(root);
1027        if (!sb->s_root) {
1028                iput(root);
1029                printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1030                goto failed_mount3;
1031        }
1032        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1033                dput(sb->s_root);
1034                sb->s_root = NULL;
1035                printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1036                goto failed_mount3;
1037        }
1038        if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1039                ext2_warning(sb, __FUNCTION__,
1040                        "mounting ext3 filesystem as ext2");
1041        ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1042        return 0;
1043
1044cantfind_ext2:
1045        if (!silent)
1046                printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1047                       sb->s_id);
1048        goto failed_mount;
1049failed_mount3:
1050        percpu_counter_destroy(&sbi->s_freeblocks_counter);
1051        percpu_counter_destroy(&sbi->s_freeinodes_counter);
1052        percpu_counter_destroy(&sbi->s_dirs_counter);
1053failed_mount2:
1054        for (i = 0; i < db_count; i++)
1055                brelse(sbi->s_group_desc[i]);
1056failed_mount_group_desc:
1057        kfree(sbi->s_group_desc);
1058        kfree(sbi->s_debts);
1059failed_mount:
1060        brelse(bh);
1061failed_sbi:
1062        sb->s_fs_info = NULL;
1063        kfree(sbi);
1064        return -EINVAL;
1065}
1066
1067static void ext2_commit_super (struct super_block * sb,
1068                               struct ext2_super_block * es)
1069{
1070        es->s_wtime = cpu_to_le32(get_seconds());
1071        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1072        sb->s_dirt = 0;
1073}
1074
1075static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1076{
1077        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1078        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1079        es->s_wtime = cpu_to_le32(get_seconds());
1080        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1081        sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1082        sb->s_dirt = 0;
1083}
1084
1085/*
1086 * In the second extended file system, it is not necessary to
1087 * write the super block since we use a mapping of the
1088 * disk super block in a buffer.
1089 *
1090 * However, this function is still used to set the fs valid
1091 * flags to 0.  We need to set this flag to 0 since the fs
1092 * may have been checked while mounted and e2fsck may have
1093 * set s_state to EXT2_VALID_FS after some corrections.
1094 */
1095
1096void ext2_write_super (struct super_block * sb)
1097{
1098        struct ext2_super_block * es;
1099        lock_kernel();
1100        if (!(sb->s_flags & MS_RDONLY)) {
1101                es = EXT2_SB(sb)->s_es;
1102
1103                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS) {
1104                        ext2_debug ("setting valid to 0\n");
1105                        es->s_state = cpu_to_le16(le16_to_cpu(es->s_state) &
1106                                                  ~EXT2_VALID_FS);
1107                        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1108                        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1109                        es->s_mtime = cpu_to_le32(get_seconds());
1110                        ext2_sync_super(sb, es);
1111                } else
1112                        ext2_commit_super (sb, es);
1113        }
1114        sb->s_dirt = 0;
1115        unlock_kernel();
1116}
1117
1118static int ext2_remount (struct super_block * sb, int * flags, char * data)
1119{
1120        struct ext2_sb_info * sbi = EXT2_SB(sb);
1121        struct ext2_super_block * es;
1122        unsigned long old_mount_opt = sbi->s_mount_opt;
1123        struct ext2_mount_options old_opts;
1124        unsigned long old_sb_flags;
1125        int err;
1126
1127        /* Store the old options */
1128        old_sb_flags = sb->s_flags;
1129        old_opts.s_mount_opt = sbi->s_mount_opt;
1130        old_opts.s_resuid = sbi->s_resuid;
1131        old_opts.s_resgid = sbi->s_resgid;
1132
1133        /*
1134         * Allow the "check" option to be passed as a remount option.
1135         */
1136        if (!parse_options (data, sbi)) {
1137                err = -EINVAL;
1138                goto restore_opts;
1139        }
1140
1141        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1142                ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1143
1144        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1145                                    EXT2_MOUNT_XIP if not */
1146
1147        if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1148                printk("XIP: Unsupported blocksize\n");
1149                err = -EINVAL;
1150                goto restore_opts;
1151        }
1152
1153        es = sbi->s_es;
1154        if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1155            (old_mount_opt & EXT2_MOUNT_XIP)) &&
1156            invalidate_inodes(sb))
1157                ext2_warning(sb, __FUNCTION__, "busy inodes while remounting "\
1158                             "xip remain in cache (no functional problem)");
1159        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1160                return 0;
1161        if (*flags & MS_RDONLY) {
1162                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1163                    !(sbi->s_mount_state & EXT2_VALID_FS))
1164                        return 0;
1165                /*
1166                 * OK, we are remounting a valid rw partition rdonly, so set
1167                 * the rdonly flag and then mark the partition as valid again.
1168                 */
1169                es->s_state = cpu_to_le16(sbi->s_mount_state);
1170                es->s_mtime = cpu_to_le32(get_seconds());
1171        } else {
1172                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1173                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
1174                if (ret) {
1175                        printk("EXT2-fs: %s: couldn't remount RDWR because of "
1176                               "unsupported optional features (%x).\n",
1177                               sb->s_id, le32_to_cpu(ret));
1178                        err = -EROFS;
1179                        goto restore_opts;
1180                }
1181                /*
1182                 * Mounting a RDONLY partition read-write, so reread and
1183                 * store the current valid flag.  (It may have been changed
1184                 * by e2fsck since we originally mounted the partition.)
1185                 */
1186                sbi->s_mount_state = le16_to_cpu(es->s_state);
1187                if (!ext2_setup_super (sb, es, 0))
1188                        sb->s_flags &= ~MS_RDONLY;
1189        }
1190        ext2_sync_super(sb, es);
1191        return 0;
1192restore_opts:
1193        sbi->s_mount_opt = old_opts.s_mount_opt;
1194        sbi->s_resuid = old_opts.s_resuid;
1195        sbi->s_resgid = old_opts.s_resgid;
1196        sb->s_flags = old_sb_flags;
1197        return err;
1198}
1199
1200static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1201{
1202        struct super_block *sb = dentry->d_sb;
1203        struct ext2_sb_info *sbi = EXT2_SB(sb);
1204        struct ext2_super_block *es = sbi->s_es;
1205        u64 fsid;
1206
1207        if (test_opt (sb, MINIX_DF))
1208                sbi->s_overhead_last = 0;
1209        else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1210                unsigned long i, overhead = 0;
1211                smp_rmb();
1212
1213                /*
1214                 * Compute the overhead (FS structures). This is constant
1215                 * for a given filesystem unless the number of block groups
1216                 * changes so we cache the previous value until it does.
1217                 */
1218
1219                /*
1220                 * All of the blocks before first_data_block are
1221                 * overhead
1222                 */
1223                overhead = le32_to_cpu(es->s_first_data_block);
1224
1225                /*
1226                 * Add the overhead attributed to the superblock and
1227                 * block group descriptors.  If the sparse superblocks
1228                 * feature is turned on, then not all groups have this.
1229                 */
1230                for (i = 0; i < sbi->s_groups_count; i++)
1231                        overhead += ext2_bg_has_super(sb, i) +
1232                                ext2_bg_num_gdb(sb, i);
1233
1234                /*
1235                 * Every block group has an inode bitmap, a block
1236                 * bitmap, and an inode table.
1237                 */
1238                overhead += (sbi->s_groups_count *
1239                             (2 + sbi->s_itb_per_group));
1240                sbi->s_overhead_last = overhead;
1241                smp_wmb();
1242                sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1243        }
1244
1245        buf->f_type = EXT2_SUPER_MAGIC;
1246        buf->f_bsize = sb->s_blocksize;
1247        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1248        buf->f_bfree = ext2_count_free_blocks(sb);
1249        es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1250        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1251        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1252                buf->f_bavail = 0;
1253        buf->f_files = le32_to_cpu(es->s_inodes_count);
1254        buf->f_ffree = ext2_count_free_inodes(sb);
1255        es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1256        buf->f_namelen = EXT2_NAME_LEN;
1257        fsid = le64_to_cpup((void *)es->s_uuid) ^
1258               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1259        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1260        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1261        return 0;
1262}
1263
1264static int ext2_get_sb(struct file_system_type *fs_type,
1265        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1266{
1267        return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1268}
1269
1270#ifdef CONFIG_QUOTA
1271
1272/* Read data from quotafile - avoid pagecache and such because we cannot afford
1273 * acquiring the locks... As quota files are never truncated and quota code
1274 * itself serializes the operations (and noone else should touch the files)
1275 * we don't have to be afraid of races */
1276static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1277                               size_t len, loff_t off)
1278{
1279        struct inode *inode = sb_dqopt(sb)->files[type];
1280        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1281        int err = 0;
1282        int offset = off & (sb->s_blocksize - 1);
1283        int tocopy;
1284        size_t toread;
1285        struct buffer_head tmp_bh;
1286        struct buffer_head *bh;
1287        loff_t i_size = i_size_read(inode);
1288
1289        if (off > i_size)
1290                return 0;
1291        if (off+len > i_size)
1292                len = i_size-off;
1293        toread = len;
1294        while (toread > 0) {
1295                tocopy = sb->s_blocksize - offset < toread ?
1296                                sb->s_blocksize - offset : toread;
1297
1298                tmp_bh.b_state = 0;
1299                err = ext2_get_block(inode, blk, &tmp_bh, 0);
1300                if (err < 0)
1301                        return err;
1302                if (!buffer_mapped(&tmp_bh))    /* A hole? */
1303                        memset(data, 0, tocopy);
1304                else {
1305                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1306                        if (!bh)
1307                                return -EIO;
1308                        memcpy(data, bh->b_data+offset, tocopy);
1309                        brelse(bh);
1310                }
1311                offset = 0;
1312                toread -= tocopy;
1313                data += tocopy;
1314                blk++;
1315        }
1316        return len;
1317}
1318
1319/* Write to quotafile */
1320static ssize_t ext2_quota_write(struct super_block *sb, int type,
1321                                const char *data, size_t len, loff_t off)
1322{
1323        struct inode *inode = sb_dqopt(sb)->files[type];
1324        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1325        int err = 0;
1326        int offset = off & (sb->s_blocksize - 1);
1327        int tocopy;
1328        size_t towrite = len;
1329        struct buffer_head tmp_bh;
1330        struct buffer_head *bh;
1331
1332        mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1333        while (towrite > 0) {
1334                tocopy = sb->s_blocksize - offset < towrite ?
1335                                sb->s_blocksize - offset : towrite;
1336
1337                tmp_bh.b_state = 0;
1338                err = ext2_get_block(inode, blk, &tmp_bh, 1);
1339                if (err < 0)
1340                        goto out;
1341                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1342                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1343                else
1344                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
1345                if (!bh) {
1346                        err = -EIO;
1347                        goto out;
1348                }
1349                lock_buffer(bh);
1350                memcpy(bh->b_data+offset, data, tocopy);
1351                flush_dcache_page(bh->b_page);
1352                set_buffer_uptodate(bh);
1353                mark_buffer_dirty(bh);
1354                unlock_buffer(bh);
1355                brelse(bh);
1356                offset = 0;
1357                towrite -= tocopy;
1358                data += tocopy;
1359                blk++;
1360        }
1361out:
1362        if (len == towrite)
1363                return err;
1364        if (inode->i_size < off+len-towrite)
1365                i_size_write(inode, off+len-towrite);
1366        inode->i_version++;
1367        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1368        mark_inode_dirty(inode);
1369        mutex_unlock(&inode->i_mutex);
1370        return len - towrite;
1371}
1372
1373#endif
1374
1375static struct file_system_type ext2_fs_type = {
1376        .owner          = THIS_MODULE,
1377        .name           = "ext2",
1378        .get_sb         = ext2_get_sb,
1379        .kill_sb        = kill_block_super,
1380        .fs_flags       = FS_REQUIRES_DEV,
1381};
1382
1383static int __init init_ext2_fs(void)
1384{
1385        int err = init_ext2_xattr();
1386        if (err)
1387                return err;
1388        err = init_inodecache();
1389        if (err)
1390                goto out1;
1391        err = register_filesystem(&ext2_fs_type);
1392        if (err)
1393                goto out;
1394        return 0;
1395out:
1396        destroy_inodecache();
1397out1:
1398        exit_ext2_xattr();
1399        return err;
1400}
1401
1402static void __exit exit_ext2_fs(void)
1403{
1404        unregister_filesystem(&ext2_fs_type);
1405        destroy_inodecache();
1406        exit_ext2_xattr();
1407}
1408
1409module_init(init_ext2_fs)
1410module_exit(exit_ext2_fs)
1411