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/vfs.h>
  30#include <linux/seq_file.h>
  31#include <linux/mount.h>
  32#include <linux/log2.h>
  33#include <linux/quotaops.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, int wait);
  42static int ext2_remount (struct super_block * sb, int * flags, char * data);
  43static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  44static int ext2_sync_fs(struct super_block *sb, int wait);
  45
  46void ext2_error(struct super_block *sb, const char *function,
  47                const char *fmt, ...)
  48{
  49        struct va_format vaf;
  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                spin_lock(&sbi->s_lock);
  56                sbi->s_mount_state |= EXT2_ERROR_FS;
  57                es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  58                spin_unlock(&sbi->s_lock);
  59                ext2_sync_super(sb, es, 1);
  60        }
  61
  62        va_start(args, fmt);
  63
  64        vaf.fmt = fmt;
  65        vaf.va = &args;
  66
  67        printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  68               sb->s_id, function, &vaf);
  69
  70        va_end(args);
  71
  72        if (test_opt(sb, ERRORS_PANIC))
  73                panic("EXT2-fs: panic from previous error\n");
  74        if (test_opt(sb, ERRORS_RO)) {
  75                ext2_msg(sb, KERN_CRIT,
  76                             "error: remounting filesystem read-only");
  77                sb->s_flags |= MS_RDONLY;
  78        }
  79}
  80
  81void ext2_msg(struct super_block *sb, const char *prefix,
  82                const char *fmt, ...)
  83{
  84        struct va_format vaf;
  85        va_list args;
  86
  87        va_start(args, fmt);
  88
  89        vaf.fmt = fmt;
  90        vaf.va = &args;
  91
  92        printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  93
  94        va_end(args);
  95}
  96
  97/*
  98 * This must be called with sbi->s_lock held.
  99 */
 100void ext2_update_dynamic_rev(struct super_block *sb)
 101{
 102        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 103
 104        if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 105                return;
 106
 107        ext2_msg(sb, KERN_WARNING,
 108                     "warning: updating to rev %d because of "
 109                     "new feature flag, running e2fsck is recommended",
 110                     EXT2_DYNAMIC_REV);
 111
 112        es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 113        es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 114        es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 115        /* leave es->s_feature_*compat flags alone */
 116        /* es->s_uuid will be set by e2fsck if empty */
 117
 118        /*
 119         * The rest of the superblock fields should be zero, and if not it
 120         * means they are likely already in use, so leave them alone.  We
 121         * can leave it up to e2fsck to clean up any inconsistencies there.
 122         */
 123}
 124
 125static void ext2_put_super (struct super_block * sb)
 126{
 127        int db_count;
 128        int i;
 129        struct ext2_sb_info *sbi = EXT2_SB(sb);
 130
 131        dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 132
 133        ext2_xattr_put_super(sb);
 134        if (!(sb->s_flags & MS_RDONLY)) {
 135                struct ext2_super_block *es = sbi->s_es;
 136
 137                spin_lock(&sbi->s_lock);
 138                es->s_state = cpu_to_le16(sbi->s_mount_state);
 139                spin_unlock(&sbi->s_lock);
 140                ext2_sync_super(sb, es, 1);
 141        }
 142        db_count = sbi->s_gdb_count;
 143        for (i = 0; i < db_count; i++)
 144                if (sbi->s_group_desc[i])
 145                        brelse (sbi->s_group_desc[i]);
 146        kfree(sbi->s_group_desc);
 147        kfree(sbi->s_debts);
 148        percpu_counter_destroy(&sbi->s_freeblocks_counter);
 149        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 150        percpu_counter_destroy(&sbi->s_dirs_counter);
 151        brelse (sbi->s_sbh);
 152        sb->s_fs_info = NULL;
 153        kfree(sbi->s_blockgroup_lock);
 154        kfree(sbi);
 155}
 156
 157static struct kmem_cache * ext2_inode_cachep;
 158
 159static struct inode *ext2_alloc_inode(struct super_block *sb)
 160{
 161        struct ext2_inode_info *ei;
 162        ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 163        if (!ei)
 164                return NULL;
 165        ei->i_block_alloc_info = NULL;
 166        ei->vfs_inode.i_version = 1;
 167        return &ei->vfs_inode;
 168}
 169
 170static void ext2_i_callback(struct rcu_head *head)
 171{
 172        struct inode *inode = container_of(head, struct inode, i_rcu);
 173        kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 174}
 175
 176static void ext2_destroy_inode(struct inode *inode)
 177{
 178        call_rcu(&inode->i_rcu, ext2_i_callback);
 179}
 180
 181static void init_once(void *foo)
 182{
 183        struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 184
 185        rwlock_init(&ei->i_meta_lock);
 186#ifdef CONFIG_EXT2_FS_XATTR
 187        init_rwsem(&ei->xattr_sem);
 188#endif
 189        mutex_init(&ei->truncate_mutex);
 190        inode_init_once(&ei->vfs_inode);
 191}
 192
 193static int init_inodecache(void)
 194{
 195        ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 196                                             sizeof(struct ext2_inode_info),
 197                                             0, (SLAB_RECLAIM_ACCOUNT|
 198                                                SLAB_MEM_SPREAD),
 199                                             init_once);
 200        if (ext2_inode_cachep == NULL)
 201                return -ENOMEM;
 202        return 0;
 203}
 204
 205static void destroy_inodecache(void)
 206{
 207        kmem_cache_destroy(ext2_inode_cachep);
 208}
 209
 210static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 211{
 212        struct super_block *sb = root->d_sb;
 213        struct ext2_sb_info *sbi = EXT2_SB(sb);
 214        struct ext2_super_block *es = sbi->s_es;
 215        unsigned long def_mount_opts;
 216
 217        spin_lock(&sbi->s_lock);
 218        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 219
 220        if (sbi->s_sb_block != 1)
 221                seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 222        if (test_opt(sb, MINIX_DF))
 223                seq_puts(seq, ",minixdf");
 224        if (test_opt(sb, GRPID))
 225                seq_puts(seq, ",grpid");
 226        if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 227                seq_puts(seq, ",nogrpid");
 228        if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 229            le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 230                seq_printf(seq, ",resuid=%u",
 231                                from_kuid_munged(&init_user_ns, sbi->s_resuid));
 232        }
 233        if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 234            le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 235                seq_printf(seq, ",resgid=%u",
 236                                from_kgid_munged(&init_user_ns, sbi->s_resgid));
 237        }
 238        if (test_opt(sb, ERRORS_RO)) {
 239                int def_errors = le16_to_cpu(es->s_errors);
 240
 241                if (def_errors == EXT2_ERRORS_PANIC ||
 242                    def_errors == EXT2_ERRORS_CONTINUE) {
 243                        seq_puts(seq, ",errors=remount-ro");
 244                }
 245        }
 246        if (test_opt(sb, ERRORS_CONT))
 247                seq_puts(seq, ",errors=continue");
 248        if (test_opt(sb, ERRORS_PANIC))
 249                seq_puts(seq, ",errors=panic");
 250        if (test_opt(sb, NO_UID32))
 251                seq_puts(seq, ",nouid32");
 252        if (test_opt(sb, DEBUG))
 253                seq_puts(seq, ",debug");
 254        if (test_opt(sb, OLDALLOC))
 255                seq_puts(seq, ",oldalloc");
 256
 257#ifdef CONFIG_EXT2_FS_XATTR
 258        if (test_opt(sb, XATTR_USER))
 259                seq_puts(seq, ",user_xattr");
 260        if (!test_opt(sb, XATTR_USER) &&
 261            (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 262                seq_puts(seq, ",nouser_xattr");
 263        }
 264#endif
 265
 266#ifdef CONFIG_EXT2_FS_POSIX_ACL
 267        if (test_opt(sb, POSIX_ACL))
 268                seq_puts(seq, ",acl");
 269        if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 270                seq_puts(seq, ",noacl");
 271#endif
 272
 273        if (test_opt(sb, NOBH))
 274                seq_puts(seq, ",nobh");
 275
 276#if defined(CONFIG_QUOTA)
 277        if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 278                seq_puts(seq, ",usrquota");
 279
 280        if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 281                seq_puts(seq, ",grpquota");
 282#endif
 283
 284#if defined(CONFIG_EXT2_FS_XIP)
 285        if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 286                seq_puts(seq, ",xip");
 287#endif
 288
 289        if (!test_opt(sb, RESERVATION))
 290                seq_puts(seq, ",noreservation");
 291
 292        spin_unlock(&sbi->s_lock);
 293        return 0;
 294}
 295
 296#ifdef CONFIG_QUOTA
 297static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 298static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 299#endif
 300
 301static const struct super_operations ext2_sops = {
 302        .alloc_inode    = ext2_alloc_inode,
 303        .destroy_inode  = ext2_destroy_inode,
 304        .write_inode    = ext2_write_inode,
 305        .evict_inode    = ext2_evict_inode,
 306        .put_super      = ext2_put_super,
 307        .sync_fs        = ext2_sync_fs,
 308        .statfs         = ext2_statfs,
 309        .remount_fs     = ext2_remount,
 310        .show_options   = ext2_show_options,
 311#ifdef CONFIG_QUOTA
 312        .quota_read     = ext2_quota_read,
 313        .quota_write    = ext2_quota_write,
 314#endif
 315};
 316
 317static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 318                u64 ino, u32 generation)
 319{
 320        struct inode *inode;
 321
 322        if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 323                return ERR_PTR(-ESTALE);
 324        if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 325                return ERR_PTR(-ESTALE);
 326
 327        /*
 328         * ext2_iget isn't quite right if the inode is currently unallocated!
 329         * However ext2_iget currently does appropriate checks to handle stale
 330         * inodes so everything is OK.
 331         */
 332        inode = ext2_iget(sb, ino);
 333        if (IS_ERR(inode))
 334                return ERR_CAST(inode);
 335        if (generation && inode->i_generation != generation) {
 336                /* we didn't find the right inode.. */
 337                iput(inode);
 338                return ERR_PTR(-ESTALE);
 339        }
 340        return inode;
 341}
 342
 343static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 344                int fh_len, int fh_type)
 345{
 346        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 347                                    ext2_nfs_get_inode);
 348}
 349
 350static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 351                int fh_len, int fh_type)
 352{
 353        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 354                                    ext2_nfs_get_inode);
 355}
 356
 357static const struct export_operations ext2_export_ops = {
 358        .fh_to_dentry = ext2_fh_to_dentry,
 359        .fh_to_parent = ext2_fh_to_parent,
 360        .get_parent = ext2_get_parent,
 361};
 362
 363static unsigned long get_sb_block(void **data)
 364{
 365        unsigned long   sb_block;
 366        char            *options = (char *) *data;
 367
 368        if (!options || strncmp(options, "sb=", 3) != 0)
 369                return 1;       /* Default location */
 370        options += 3;
 371        sb_block = simple_strtoul(options, &options, 0);
 372        if (*options && *options != ',') {
 373                printk("EXT2-fs: Invalid sb specification: %s\n",
 374                       (char *) *data);
 375                return 1;
 376        }
 377        if (*options == ',')
 378                options++;
 379        *data = (void *) options;
 380        return sb_block;
 381}
 382
 383enum {
 384        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 385        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 386        Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 387        Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 388        Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 389        Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 390};
 391
 392static const match_table_t tokens = {
 393        {Opt_bsd_df, "bsddf"},
 394        {Opt_minix_df, "minixdf"},
 395        {Opt_grpid, "grpid"},
 396        {Opt_grpid, "bsdgroups"},
 397        {Opt_nogrpid, "nogrpid"},
 398        {Opt_nogrpid, "sysvgroups"},
 399        {Opt_resgid, "resgid=%u"},
 400        {Opt_resuid, "resuid=%u"},
 401        {Opt_sb, "sb=%u"},
 402        {Opt_err_cont, "errors=continue"},
 403        {Opt_err_panic, "errors=panic"},
 404        {Opt_err_ro, "errors=remount-ro"},
 405        {Opt_nouid32, "nouid32"},
 406        {Opt_nocheck, "check=none"},
 407        {Opt_nocheck, "nocheck"},
 408        {Opt_debug, "debug"},
 409        {Opt_oldalloc, "oldalloc"},
 410        {Opt_orlov, "orlov"},
 411        {Opt_nobh, "nobh"},
 412        {Opt_user_xattr, "user_xattr"},
 413        {Opt_nouser_xattr, "nouser_xattr"},
 414        {Opt_acl, "acl"},
 415        {Opt_noacl, "noacl"},
 416        {Opt_xip, "xip"},
 417        {Opt_grpquota, "grpquota"},
 418        {Opt_ignore, "noquota"},
 419        {Opt_quota, "quota"},
 420        {Opt_usrquota, "usrquota"},
 421        {Opt_reservation, "reservation"},
 422        {Opt_noreservation, "noreservation"},
 423        {Opt_err, NULL}
 424};
 425
 426static int parse_options(char *options, struct super_block *sb)
 427{
 428        char *p;
 429        struct ext2_sb_info *sbi = EXT2_SB(sb);
 430        substring_t args[MAX_OPT_ARGS];
 431        int option;
 432        kuid_t uid;
 433        kgid_t gid;
 434
 435        if (!options)
 436                return 1;
 437
 438        while ((p = strsep (&options, ",")) != NULL) {
 439                int token;
 440                if (!*p)
 441                        continue;
 442
 443                token = match_token(p, tokens, args);
 444                switch (token) {
 445                case Opt_bsd_df:
 446                        clear_opt (sbi->s_mount_opt, MINIX_DF);
 447                        break;
 448                case Opt_minix_df:
 449                        set_opt (sbi->s_mount_opt, MINIX_DF);
 450                        break;
 451                case Opt_grpid:
 452                        set_opt (sbi->s_mount_opt, GRPID);
 453                        break;
 454                case Opt_nogrpid:
 455                        clear_opt (sbi->s_mount_opt, GRPID);
 456                        break;
 457                case Opt_resuid:
 458                        if (match_int(&args[0], &option))
 459                                return 0;
 460                        uid = make_kuid(current_user_ns(), option);
 461                        if (!uid_valid(uid)) {
 462                                ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 463                                return -1;
 464
 465                        }
 466                        sbi->s_resuid = uid;
 467                        break;
 468                case Opt_resgid:
 469                        if (match_int(&args[0], &option))
 470                                return 0;
 471                        gid = make_kgid(current_user_ns(), option);
 472                        if (!gid_valid(gid)) {
 473                                ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 474                                return -1;
 475                        }
 476                        sbi->s_resgid = gid;
 477                        break;
 478                case Opt_sb:
 479                        /* handled by get_sb_block() instead of here */
 480                        /* *sb_block = match_int(&args[0]); */
 481                        break;
 482                case Opt_err_panic:
 483                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 484                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 485                        set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 486                        break;
 487                case Opt_err_ro:
 488                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 489                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 490                        set_opt (sbi->s_mount_opt, ERRORS_RO);
 491                        break;
 492                case Opt_err_cont:
 493                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 494                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 495                        set_opt (sbi->s_mount_opt, ERRORS_CONT);
 496                        break;
 497                case Opt_nouid32:
 498                        set_opt (sbi->s_mount_opt, NO_UID32);
 499                        break;
 500                case Opt_nocheck:
 501                        clear_opt (sbi->s_mount_opt, CHECK);
 502                        break;
 503                case Opt_debug:
 504                        set_opt (sbi->s_mount_opt, DEBUG);
 505                        break;
 506                case Opt_oldalloc:
 507                        set_opt (sbi->s_mount_opt, OLDALLOC);
 508                        break;
 509                case Opt_orlov:
 510                        clear_opt (sbi->s_mount_opt, OLDALLOC);
 511                        break;
 512                case Opt_nobh:
 513                        set_opt (sbi->s_mount_opt, NOBH);
 514                        break;
 515#ifdef CONFIG_EXT2_FS_XATTR
 516                case Opt_user_xattr:
 517                        set_opt (sbi->s_mount_opt, XATTR_USER);
 518                        break;
 519                case Opt_nouser_xattr:
 520                        clear_opt (sbi->s_mount_opt, XATTR_USER);
 521                        break;
 522#else
 523                case Opt_user_xattr:
 524                case Opt_nouser_xattr:
 525                        ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 526                                "not supported");
 527                        break;
 528#endif
 529#ifdef CONFIG_EXT2_FS_POSIX_ACL
 530                case Opt_acl:
 531                        set_opt(sbi->s_mount_opt, POSIX_ACL);
 532                        break;
 533                case Opt_noacl:
 534                        clear_opt(sbi->s_mount_opt, POSIX_ACL);
 535                        break;
 536#else
 537                case Opt_acl:
 538                case Opt_noacl:
 539                        ext2_msg(sb, KERN_INFO,
 540                                "(no)acl options not supported");
 541                        break;
 542#endif
 543                case Opt_xip:
 544#ifdef CONFIG_EXT2_FS_XIP
 545                        set_opt (sbi->s_mount_opt, XIP);
 546#else
 547                        ext2_msg(sb, KERN_INFO, "xip option not supported");
 548#endif
 549                        break;
 550
 551#if defined(CONFIG_QUOTA)
 552                case Opt_quota:
 553                case Opt_usrquota:
 554                        set_opt(sbi->s_mount_opt, USRQUOTA);
 555                        break;
 556
 557                case Opt_grpquota:
 558                        set_opt(sbi->s_mount_opt, GRPQUOTA);
 559                        break;
 560#else
 561                case Opt_quota:
 562                case Opt_usrquota:
 563                case Opt_grpquota:
 564                        ext2_msg(sb, KERN_INFO,
 565                                "quota operations not supported");
 566                        break;
 567#endif
 568
 569                case Opt_reservation:
 570                        set_opt(sbi->s_mount_opt, RESERVATION);
 571                        ext2_msg(sb, KERN_INFO, "reservations ON");
 572                        break;
 573                case Opt_noreservation:
 574                        clear_opt(sbi->s_mount_opt, RESERVATION);
 575                        ext2_msg(sb, KERN_INFO, "reservations OFF");
 576                        break;
 577                case Opt_ignore:
 578                        break;
 579                default:
 580                        return 0;
 581                }
 582        }
 583        return 1;
 584}
 585
 586static int ext2_setup_super (struct super_block * sb,
 587                              struct ext2_super_block * es,
 588                              int read_only)
 589{
 590        int res = 0;
 591        struct ext2_sb_info *sbi = EXT2_SB(sb);
 592
 593        if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 594                ext2_msg(sb, KERN_ERR,
 595                        "error: revision level too high, "
 596                        "forcing read-only mode");
 597                res = MS_RDONLY;
 598        }
 599        if (read_only)
 600                return res;
 601        if (!(sbi->s_mount_state & EXT2_VALID_FS))
 602                ext2_msg(sb, KERN_WARNING,
 603                        "warning: mounting unchecked fs, "
 604                        "running e2fsck is recommended");
 605        else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 606                ext2_msg(sb, KERN_WARNING,
 607                        "warning: mounting fs with errors, "
 608                        "running e2fsck is recommended");
 609        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 610                 le16_to_cpu(es->s_mnt_count) >=
 611                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 612                ext2_msg(sb, KERN_WARNING,
 613                        "warning: maximal mount count reached, "
 614                        "running e2fsck is recommended");
 615        else if (le32_to_cpu(es->s_checkinterval) &&
 616                (le32_to_cpu(es->s_lastcheck) +
 617                        le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 618                ext2_msg(sb, KERN_WARNING,
 619                        "warning: checktime reached, "
 620                        "running e2fsck is recommended");
 621        if (!le16_to_cpu(es->s_max_mnt_count))
 622                es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 623        le16_add_cpu(&es->s_mnt_count, 1);
 624        if (test_opt (sb, DEBUG))
 625                ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 626                        "bpg=%lu, ipg=%lu, mo=%04lx]",
 627                        EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 628                        sbi->s_frag_size,
 629                        sbi->s_groups_count,
 630                        EXT2_BLOCKS_PER_GROUP(sb),
 631                        EXT2_INODES_PER_GROUP(sb),
 632                        sbi->s_mount_opt);
 633        return res;
 634}
 635
 636static int ext2_check_descriptors(struct super_block *sb)
 637{
 638        int i;
 639        struct ext2_sb_info *sbi = EXT2_SB(sb);
 640
 641        ext2_debug ("Checking group descriptors");
 642
 643        for (i = 0; i < sbi->s_groups_count; i++) {
 644                struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 645                ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 646                ext2_fsblk_t last_block;
 647
 648                if (i == sbi->s_groups_count - 1)
 649                        last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 650                else
 651                        last_block = first_block +
 652                                (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 653
 654                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 655                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 656                {
 657                        ext2_error (sb, "ext2_check_descriptors",
 658                                    "Block bitmap for group %d"
 659                                    " not in group (block %lu)!",
 660                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 661                        return 0;
 662                }
 663                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 664                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 665                {
 666                        ext2_error (sb, "ext2_check_descriptors",
 667                                    "Inode bitmap for group %d"
 668                                    " not in group (block %lu)!",
 669                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 670                        return 0;
 671                }
 672                if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 673                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 674                    last_block)
 675                {
 676                        ext2_error (sb, "ext2_check_descriptors",
 677                                    "Inode table for group %d"
 678                                    " not in group (block %lu)!",
 679                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 680                        return 0;
 681                }
 682        }
 683        return 1;
 684}
 685
 686/*
 687 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 688 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 689 * We need to be 1 filesystem block less than the 2^32 sector limit.
 690 */
 691static loff_t ext2_max_size(int bits)
 692{
 693        loff_t res = EXT2_NDIR_BLOCKS;
 694        int meta_blocks;
 695        loff_t upper_limit;
 696
 697        /* This is calculated to be the largest file size for a
 698         * dense, file such that the total number of
 699         * sectors in the file, including data and all indirect blocks,
 700         * does not exceed 2^32 -1
 701         * __u32 i_blocks representing the total number of
 702         * 512 bytes blocks of the file
 703         */
 704        upper_limit = (1LL << 32) - 1;
 705
 706        /* total blocks in file system block size */
 707        upper_limit >>= (bits - 9);
 708
 709
 710        /* indirect blocks */
 711        meta_blocks = 1;
 712        /* double indirect blocks */
 713        meta_blocks += 1 + (1LL << (bits-2));
 714        /* tripple indirect blocks */
 715        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 716
 717        upper_limit -= meta_blocks;
 718        upper_limit <<= bits;
 719
 720        res += 1LL << (bits-2);
 721        res += 1LL << (2*(bits-2));
 722        res += 1LL << (3*(bits-2));
 723        res <<= bits;
 724        if (res > upper_limit)
 725                res = upper_limit;
 726
 727        if (res > MAX_LFS_FILESIZE)
 728                res = MAX_LFS_FILESIZE;
 729
 730        return res;
 731}
 732
 733static unsigned long descriptor_loc(struct super_block *sb,
 734                                    unsigned long logic_sb_block,
 735                                    int nr)
 736{
 737        struct ext2_sb_info *sbi = EXT2_SB(sb);
 738        unsigned long bg, first_meta_bg;
 739        int has_super = 0;
 740        
 741        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 742
 743        if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 744            nr < first_meta_bg)
 745                return (logic_sb_block + nr + 1);
 746        bg = sbi->s_desc_per_block * nr;
 747        if (ext2_bg_has_super(sb, bg))
 748                has_super = 1;
 749
 750        return ext2_group_first_block_no(sb, bg) + has_super;
 751}
 752
 753static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 754{
 755        struct buffer_head * bh;
 756        struct ext2_sb_info * sbi;
 757        struct ext2_super_block * es;
 758        struct inode *root;
 759        unsigned long block;
 760        unsigned long sb_block = get_sb_block(&data);
 761        unsigned long logic_sb_block;
 762        unsigned long offset = 0;
 763        unsigned long def_mount_opts;
 764        long ret = -EINVAL;
 765        int blocksize = BLOCK_SIZE;
 766        int db_count;
 767        int i, j;
 768        __le32 features;
 769        int err;
 770
 771        err = -ENOMEM;
 772        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 773        if (!sbi)
 774                goto failed_unlock;
 775
 776        sbi->s_blockgroup_lock =
 777                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 778        if (!sbi->s_blockgroup_lock) {
 779                kfree(sbi);
 780                goto failed_unlock;
 781        }
 782        sb->s_fs_info = sbi;
 783        sbi->s_sb_block = sb_block;
 784
 785        spin_lock_init(&sbi->s_lock);
 786
 787        /*
 788         * See what the current blocksize for the device is, and
 789         * use that as the blocksize.  Otherwise (or if the blocksize
 790         * is smaller than the default) use the default.
 791         * This is important for devices that have a hardware
 792         * sectorsize that is larger than the default.
 793         */
 794        blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 795        if (!blocksize) {
 796                ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 797                goto failed_sbi;
 798        }
 799
 800        /*
 801         * If the superblock doesn't start on a hardware sector boundary,
 802         * calculate the offset.  
 803         */
 804        if (blocksize != BLOCK_SIZE) {
 805                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 806                offset = (sb_block*BLOCK_SIZE) % blocksize;
 807        } else {
 808                logic_sb_block = sb_block;
 809        }
 810
 811        if (!(bh = sb_bread(sb, logic_sb_block))) {
 812                ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 813                goto failed_sbi;
 814        }
 815        /*
 816         * Note: s_es must be initialized as soon as possible because
 817         *       some ext2 macro-instructions depend on its value
 818         */
 819        es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 820        sbi->s_es = es;
 821        sb->s_magic = le16_to_cpu(es->s_magic);
 822
 823        if (sb->s_magic != EXT2_SUPER_MAGIC)
 824                goto cantfind_ext2;
 825
 826        /* Set defaults before we parse the mount options */
 827        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 828        if (def_mount_opts & EXT2_DEFM_DEBUG)
 829                set_opt(sbi->s_mount_opt, DEBUG);
 830        if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 831                set_opt(sbi->s_mount_opt, GRPID);
 832        if (def_mount_opts & EXT2_DEFM_UID16)
 833                set_opt(sbi->s_mount_opt, NO_UID32);
 834#ifdef CONFIG_EXT2_FS_XATTR
 835        if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 836                set_opt(sbi->s_mount_opt, XATTR_USER);
 837#endif
 838#ifdef CONFIG_EXT2_FS_POSIX_ACL
 839        if (def_mount_opts & EXT2_DEFM_ACL)
 840                set_opt(sbi->s_mount_opt, POSIX_ACL);
 841#endif
 842        
 843        if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 844                set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 845        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 846                set_opt(sbi->s_mount_opt, ERRORS_CONT);
 847        else
 848                set_opt(sbi->s_mount_opt, ERRORS_RO);
 849
 850        sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 851        sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 852        
 853        set_opt(sbi->s_mount_opt, RESERVATION);
 854
 855        if (!parse_options((char *) data, sb))
 856                goto failed_mount;
 857
 858        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 859                ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 860                 MS_POSIXACL : 0);
 861
 862        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 863                                    EXT2_MOUNT_XIP if not */
 864
 865        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 866            (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 867             EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 868             EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 869                ext2_msg(sb, KERN_WARNING,
 870                        "warning: feature flags set on rev 0 fs, "
 871                        "running e2fsck is recommended");
 872        /*
 873         * Check feature flags regardless of the revision level, since we
 874         * previously didn't change the revision level when setting the flags,
 875         * so there is a chance incompat flags are set on a rev 0 filesystem.
 876         */
 877        features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 878        if (features) {
 879                ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 880                       "unsupported optional features (%x)",
 881                        le32_to_cpu(features));
 882                goto failed_mount;
 883        }
 884        if (!(sb->s_flags & MS_RDONLY) &&
 885            (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 886                ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 887                       "unsupported optional features (%x)",
 888                       le32_to_cpu(features));
 889                goto failed_mount;
 890        }
 891
 892        blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 893
 894        if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
 895                if (!silent)
 896                        ext2_msg(sb, KERN_ERR,
 897                                "error: unsupported blocksize for xip");
 898                goto failed_mount;
 899        }
 900
 901        /* If the blocksize doesn't match, re-read the thing.. */
 902        if (sb->s_blocksize != blocksize) {
 903                brelse(bh);
 904
 905                if (!sb_set_blocksize(sb, blocksize)) {
 906                        ext2_msg(sb, KERN_ERR,
 907                                "error: bad blocksize %d", blocksize);
 908                        goto failed_sbi;
 909                }
 910
 911                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 912                offset = (sb_block*BLOCK_SIZE) % blocksize;
 913                bh = sb_bread(sb, logic_sb_block);
 914                if(!bh) {
 915                        ext2_msg(sb, KERN_ERR, "error: couldn't read"
 916                                "superblock on 2nd try");
 917                        goto failed_sbi;
 918                }
 919                es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 920                sbi->s_es = es;
 921                if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 922                        ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 923                        goto failed_mount;
 924                }
 925        }
 926
 927        sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 928        sb->s_max_links = EXT2_LINK_MAX;
 929
 930        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 931                sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 932                sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 933        } else {
 934                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 935                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 936                if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 937                    !is_power_of_2(sbi->s_inode_size) ||
 938                    (sbi->s_inode_size > blocksize)) {
 939                        ext2_msg(sb, KERN_ERR,
 940                                "error: unsupported inode size: %d",
 941                                sbi->s_inode_size);
 942                        goto failed_mount;
 943                }
 944        }
 945
 946        sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 947                                   le32_to_cpu(es->s_log_frag_size);
 948        if (sbi->s_frag_size == 0)
 949                goto cantfind_ext2;
 950        sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 951
 952        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 953        sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 954        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 955
 956        if (EXT2_INODE_SIZE(sb) == 0)
 957                goto cantfind_ext2;
 958        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 959        if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 960                goto cantfind_ext2;
 961        sbi->s_itb_per_group = sbi->s_inodes_per_group /
 962                                        sbi->s_inodes_per_block;
 963        sbi->s_desc_per_block = sb->s_blocksize /
 964                                        sizeof (struct ext2_group_desc);
 965        sbi->s_sbh = bh;
 966        sbi->s_mount_state = le16_to_cpu(es->s_state);
 967        sbi->s_addr_per_block_bits =
 968                ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 969        sbi->s_desc_per_block_bits =
 970                ilog2 (EXT2_DESC_PER_BLOCK(sb));
 971
 972        if (sb->s_magic != EXT2_SUPER_MAGIC)
 973                goto cantfind_ext2;
 974
 975        if (sb->s_blocksize != bh->b_size) {
 976                if (!silent)
 977                        ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
 978                goto failed_mount;
 979        }
 980
 981        if (sb->s_blocksize != sbi->s_frag_size) {
 982                ext2_msg(sb, KERN_ERR,
 983                        "error: fragsize %lu != blocksize %lu"
 984                        "(not supported yet)",
 985                        sbi->s_frag_size, sb->s_blocksize);
 986                goto failed_mount;
 987        }
 988
 989        if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 990                ext2_msg(sb, KERN_ERR,
 991                        "error: #blocks per group too big: %lu",
 992                        sbi->s_blocks_per_group);
 993                goto failed_mount;
 994        }
 995        if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 996                ext2_msg(sb, KERN_ERR,
 997                        "error: #fragments per group too big: %lu",
 998                        sbi->s_frags_per_group);
 999                goto failed_mount;
1000        }
1001        if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1002                ext2_msg(sb, KERN_ERR,
1003                        "error: #inodes per group too big: %lu",
1004                        sbi->s_inodes_per_group);
1005                goto failed_mount;
1006        }
1007
1008        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1009                goto cantfind_ext2;
1010        sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1011                                le32_to_cpu(es->s_first_data_block) - 1)
1012                                        / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1013        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1014                   EXT2_DESC_PER_BLOCK(sb);
1015        sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1016        if (sbi->s_group_desc == NULL) {
1017                ext2_msg(sb, KERN_ERR, "error: not enough memory");
1018                goto failed_mount;
1019        }
1020        bgl_lock_init(sbi->s_blockgroup_lock);
1021        sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1022        if (!sbi->s_debts) {
1023                ext2_msg(sb, KERN_ERR, "error: not enough memory");
1024                goto failed_mount_group_desc;
1025        }
1026        for (i = 0; i < db_count; i++) {
1027                block = descriptor_loc(sb, logic_sb_block, i);
1028                sbi->s_group_desc[i] = sb_bread(sb, block);
1029                if (!sbi->s_group_desc[i]) {
1030                        for (j = 0; j < i; j++)
1031                                brelse (sbi->s_group_desc[j]);
1032                        ext2_msg(sb, KERN_ERR,
1033                                "error: unable to read group descriptors");
1034                        goto failed_mount_group_desc;
1035                }
1036        }
1037        if (!ext2_check_descriptors (sb)) {
1038                ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1039                goto failed_mount2;
1040        }
1041        sbi->s_gdb_count = db_count;
1042        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1043        spin_lock_init(&sbi->s_next_gen_lock);
1044
1045        /* per fileystem reservation list head & lock */
1046        spin_lock_init(&sbi->s_rsv_window_lock);
1047        sbi->s_rsv_window_root = RB_ROOT;
1048        /*
1049         * Add a single, static dummy reservation to the start of the
1050         * reservation window list --- it gives us a placeholder for
1051         * append-at-start-of-list which makes the allocation logic
1052         * _much_ simpler.
1053         */
1054        sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1055        sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1056        sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1057        sbi->s_rsv_window_head.rsv_goal_size = 0;
1058        ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1059
1060        err = percpu_counter_init(&sbi->s_freeblocks_counter,
1061                                ext2_count_free_blocks(sb));
1062        if (!err) {
1063                err = percpu_counter_init(&sbi->s_freeinodes_counter,
1064                                ext2_count_free_inodes(sb));
1065        }
1066        if (!err) {
1067                err = percpu_counter_init(&sbi->s_dirs_counter,
1068                                ext2_count_dirs(sb));
1069        }
1070        if (err) {
1071                ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1072                goto failed_mount3;
1073        }
1074        /*
1075         * set up enough so that it can read an inode
1076         */
1077        sb->s_op = &ext2_sops;
1078        sb->s_export_op = &ext2_export_ops;
1079        sb->s_xattr = ext2_xattr_handlers;
1080
1081#ifdef CONFIG_QUOTA
1082        sb->dq_op = &dquot_operations;
1083        sb->s_qcop = &dquot_quotactl_ops;
1084#endif
1085
1086        root = ext2_iget(sb, EXT2_ROOT_INO);
1087        if (IS_ERR(root)) {
1088                ret = PTR_ERR(root);
1089                goto failed_mount3;
1090        }
1091        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1092                iput(root);
1093                ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1094                goto failed_mount3;
1095        }
1096
1097        sb->s_root = d_make_root(root);
1098        if (!sb->s_root) {
1099                ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1100                ret = -ENOMEM;
1101                goto failed_mount3;
1102        }
1103        if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1104                ext2_msg(sb, KERN_WARNING,
1105                        "warning: mounting ext3 filesystem as ext2");
1106        if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1107                sb->s_flags |= MS_RDONLY;
1108        ext2_write_super(sb);
1109        return 0;
1110
1111cantfind_ext2:
1112        if (!silent)
1113                ext2_msg(sb, KERN_ERR,
1114                        "error: can't find an ext2 filesystem on dev %s.",
1115                        sb->s_id);
1116        goto failed_mount;
1117failed_mount3:
1118        percpu_counter_destroy(&sbi->s_freeblocks_counter);
1119        percpu_counter_destroy(&sbi->s_freeinodes_counter);
1120        percpu_counter_destroy(&sbi->s_dirs_counter);
1121failed_mount2:
1122        for (i = 0; i < db_count; i++)
1123                brelse(sbi->s_group_desc[i]);
1124failed_mount_group_desc:
1125        kfree(sbi->s_group_desc);
1126        kfree(sbi->s_debts);
1127failed_mount:
1128        brelse(bh);
1129failed_sbi:
1130        sb->s_fs_info = NULL;
1131        kfree(sbi->s_blockgroup_lock);
1132        kfree(sbi);
1133failed_unlock:
1134        return ret;
1135}
1136
1137static void ext2_clear_super_error(struct super_block *sb)
1138{
1139        struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1140
1141        if (buffer_write_io_error(sbh)) {
1142                /*
1143                 * Oh, dear.  A previous attempt to write the
1144                 * superblock failed.  This could happen because the
1145                 * USB device was yanked out.  Or it could happen to
1146                 * be a transient write error and maybe the block will
1147                 * be remapped.  Nothing we can do but to retry the
1148                 * write and hope for the best.
1149                 */
1150                ext2_msg(sb, KERN_ERR,
1151                       "previous I/O error to superblock detected\n");
1152                clear_buffer_write_io_error(sbh);
1153                set_buffer_uptodate(sbh);
1154        }
1155}
1156
1157static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1158                            int wait)
1159{
1160        ext2_clear_super_error(sb);
1161        spin_lock(&EXT2_SB(sb)->s_lock);
1162        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1163        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1164        es->s_wtime = cpu_to_le32(get_seconds());
1165        /* unlock before we do IO */
1166        spin_unlock(&EXT2_SB(sb)->s_lock);
1167        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1168        if (wait)
1169                sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1170}
1171
1172/*
1173 * In the second extended file system, it is not necessary to
1174 * write the super block since we use a mapping of the
1175 * disk super block in a buffer.
1176 *
1177 * However, this function is still used to set the fs valid
1178 * flags to 0.  We need to set this flag to 0 since the fs
1179 * may have been checked while mounted and e2fsck may have
1180 * set s_state to EXT2_VALID_FS after some corrections.
1181 */
1182static int ext2_sync_fs(struct super_block *sb, int wait)
1183{
1184        struct ext2_sb_info *sbi = EXT2_SB(sb);
1185        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1186
1187        spin_lock(&sbi->s_lock);
1188        if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1189                ext2_debug("setting valid to 0\n");
1190                es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1191        }
1192        spin_unlock(&sbi->s_lock);
1193        ext2_sync_super(sb, es, wait);
1194        return 0;
1195}
1196
1197
1198void ext2_write_super(struct super_block *sb)
1199{
1200        if (!(sb->s_flags & MS_RDONLY))
1201                ext2_sync_fs(sb, 1);
1202}
1203
1204static int ext2_remount (struct super_block * sb, int * flags, char * data)
1205{
1206        struct ext2_sb_info * sbi = EXT2_SB(sb);
1207        struct ext2_super_block * es;
1208        unsigned long old_mount_opt = sbi->s_mount_opt;
1209        struct ext2_mount_options old_opts;
1210        unsigned long old_sb_flags;
1211        int err;
1212
1213        spin_lock(&sbi->s_lock);
1214
1215        /* Store the old options */
1216        old_sb_flags = sb->s_flags;
1217        old_opts.s_mount_opt = sbi->s_mount_opt;
1218        old_opts.s_resuid = sbi->s_resuid;
1219        old_opts.s_resgid = sbi->s_resgid;
1220
1221        /*
1222         * Allow the "check" option to be passed as a remount option.
1223         */
1224        if (!parse_options(data, sb)) {
1225                err = -EINVAL;
1226                goto restore_opts;
1227        }
1228
1229        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1230                ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1231
1232        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1233                                    EXT2_MOUNT_XIP if not */
1234
1235        if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1236                ext2_msg(sb, KERN_WARNING,
1237                        "warning: unsupported blocksize for xip");
1238                err = -EINVAL;
1239                goto restore_opts;
1240        }
1241
1242        es = sbi->s_es;
1243        if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
1244                ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1245                         "xip flag with busy inodes while remounting");
1246                sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1247                sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1248        }
1249        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1250                spin_unlock(&sbi->s_lock);
1251                return 0;
1252        }
1253        if (*flags & MS_RDONLY) {
1254                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1255                    !(sbi->s_mount_state & EXT2_VALID_FS)) {
1256                        spin_unlock(&sbi->s_lock);
1257                        return 0;
1258                }
1259
1260                /*
1261                 * OK, we are remounting a valid rw partition rdonly, so set
1262                 * the rdonly flag and then mark the partition as valid again.
1263                 */
1264                es->s_state = cpu_to_le16(sbi->s_mount_state);
1265                es->s_mtime = cpu_to_le32(get_seconds());
1266                spin_unlock(&sbi->s_lock);
1267
1268                err = dquot_suspend(sb, -1);
1269                if (err < 0) {
1270                        spin_lock(&sbi->s_lock);
1271                        goto restore_opts;
1272                }
1273
1274                ext2_sync_super(sb, es, 1);
1275        } else {
1276                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1277                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
1278                if (ret) {
1279                        ext2_msg(sb, KERN_WARNING,
1280                                "warning: couldn't remount RDWR because of "
1281                                "unsupported optional features (%x).",
1282                                le32_to_cpu(ret));
1283                        err = -EROFS;
1284                        goto restore_opts;
1285                }
1286                /*
1287                 * Mounting a RDONLY partition read-write, so reread and
1288                 * store the current valid flag.  (It may have been changed
1289                 * by e2fsck since we originally mounted the partition.)
1290                 */
1291                sbi->s_mount_state = le16_to_cpu(es->s_state);
1292                if (!ext2_setup_super (sb, es, 0))
1293                        sb->s_flags &= ~MS_RDONLY;
1294                spin_unlock(&sbi->s_lock);
1295
1296                ext2_write_super(sb);
1297
1298                dquot_resume(sb, -1);
1299        }
1300
1301        return 0;
1302restore_opts:
1303        sbi->s_mount_opt = old_opts.s_mount_opt;
1304        sbi->s_resuid = old_opts.s_resuid;
1305        sbi->s_resgid = old_opts.s_resgid;
1306        sb->s_flags = old_sb_flags;
1307        spin_unlock(&sbi->s_lock);
1308        return err;
1309}
1310
1311static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1312{
1313        struct super_block *sb = dentry->d_sb;
1314        struct ext2_sb_info *sbi = EXT2_SB(sb);
1315        struct ext2_super_block *es = sbi->s_es;
1316        u64 fsid;
1317
1318        spin_lock(&sbi->s_lock);
1319
1320        if (test_opt (sb, MINIX_DF))
1321                sbi->s_overhead_last = 0;
1322        else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1323                unsigned long i, overhead = 0;
1324                smp_rmb();
1325
1326                /*
1327                 * Compute the overhead (FS structures). This is constant
1328                 * for a given filesystem unless the number of block groups
1329                 * changes so we cache the previous value until it does.
1330                 */
1331
1332                /*
1333                 * All of the blocks before first_data_block are
1334                 * overhead
1335                 */
1336                overhead = le32_to_cpu(es->s_first_data_block);
1337
1338                /*
1339                 * Add the overhead attributed to the superblock and
1340                 * block group descriptors.  If the sparse superblocks
1341                 * feature is turned on, then not all groups have this.
1342                 */
1343                for (i = 0; i < sbi->s_groups_count; i++)
1344                        overhead += ext2_bg_has_super(sb, i) +
1345                                ext2_bg_num_gdb(sb, i);
1346
1347                /*
1348                 * Every block group has an inode bitmap, a block
1349                 * bitmap, and an inode table.
1350                 */
1351                overhead += (sbi->s_groups_count *
1352                             (2 + sbi->s_itb_per_group));
1353                sbi->s_overhead_last = overhead;
1354                smp_wmb();
1355                sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1356        }
1357
1358        buf->f_type = EXT2_SUPER_MAGIC;
1359        buf->f_bsize = sb->s_blocksize;
1360        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1361        buf->f_bfree = ext2_count_free_blocks(sb);
1362        es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1363        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1364        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1365                buf->f_bavail = 0;
1366        buf->f_files = le32_to_cpu(es->s_inodes_count);
1367        buf->f_ffree = ext2_count_free_inodes(sb);
1368        es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1369        buf->f_namelen = EXT2_NAME_LEN;
1370        fsid = le64_to_cpup((void *)es->s_uuid) ^
1371               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1372        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1373        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1374        spin_unlock(&sbi->s_lock);
1375        return 0;
1376}
1377
1378static struct dentry *ext2_mount(struct file_system_type *fs_type,
1379        int flags, const char *dev_name, void *data)
1380{
1381        return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1382}
1383
1384#ifdef CONFIG_QUOTA
1385
1386/* Read data from quotafile - avoid pagecache and such because we cannot afford
1387 * acquiring the locks... As quota files are never truncated and quota code
1388 * itself serializes the operations (and no one else should touch the files)
1389 * we don't have to be afraid of races */
1390static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1391                               size_t len, loff_t off)
1392{
1393        struct inode *inode = sb_dqopt(sb)->files[type];
1394        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1395        int err = 0;
1396        int offset = off & (sb->s_blocksize - 1);
1397        int tocopy;
1398        size_t toread;
1399        struct buffer_head tmp_bh;
1400        struct buffer_head *bh;
1401        loff_t i_size = i_size_read(inode);
1402
1403        if (off > i_size)
1404                return 0;
1405        if (off+len > i_size)
1406                len = i_size-off;
1407        toread = len;
1408        while (toread > 0) {
1409                tocopy = sb->s_blocksize - offset < toread ?
1410                                sb->s_blocksize - offset : toread;
1411
1412                tmp_bh.b_state = 0;
1413                tmp_bh.b_size = sb->s_blocksize;
1414                err = ext2_get_block(inode, blk, &tmp_bh, 0);
1415                if (err < 0)
1416                        return err;
1417                if (!buffer_mapped(&tmp_bh))    /* A hole? */
1418                        memset(data, 0, tocopy);
1419                else {
1420                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1421                        if (!bh)
1422                                return -EIO;
1423                        memcpy(data, bh->b_data+offset, tocopy);
1424                        brelse(bh);
1425                }
1426                offset = 0;
1427                toread -= tocopy;
1428                data += tocopy;
1429                blk++;
1430        }
1431        return len;
1432}
1433
1434/* Write to quotafile */
1435static ssize_t ext2_quota_write(struct super_block *sb, int type,
1436                                const char *data, size_t len, loff_t off)
1437{
1438        struct inode *inode = sb_dqopt(sb)->files[type];
1439        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1440        int err = 0;
1441        int offset = off & (sb->s_blocksize - 1);
1442        int tocopy;
1443        size_t towrite = len;
1444        struct buffer_head tmp_bh;
1445        struct buffer_head *bh;
1446
1447        while (towrite > 0) {
1448                tocopy = sb->s_blocksize - offset < towrite ?
1449                                sb->s_blocksize - offset : towrite;
1450
1451                tmp_bh.b_state = 0;
1452                err = ext2_get_block(inode, blk, &tmp_bh, 1);
1453                if (err < 0)
1454                        goto out;
1455                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1456                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1457                else
1458                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
1459                if (!bh) {
1460                        err = -EIO;
1461                        goto out;
1462                }
1463                lock_buffer(bh);
1464                memcpy(bh->b_data+offset, data, tocopy);
1465                flush_dcache_page(bh->b_page);
1466                set_buffer_uptodate(bh);
1467                mark_buffer_dirty(bh);
1468                unlock_buffer(bh);
1469                brelse(bh);
1470                offset = 0;
1471                towrite -= tocopy;
1472                data += tocopy;
1473                blk++;
1474        }
1475out:
1476        if (len == towrite)
1477                return err;
1478        if (inode->i_size < off+len-towrite)
1479                i_size_write(inode, off+len-towrite);
1480        inode->i_version++;
1481        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1482        mark_inode_dirty(inode);
1483        return len - towrite;
1484}
1485
1486#endif
1487
1488static struct file_system_type ext2_fs_type = {
1489        .owner          = THIS_MODULE,
1490        .name           = "ext2",
1491        .mount          = ext2_mount,
1492        .kill_sb        = kill_block_super,
1493        .fs_flags       = FS_REQUIRES_DEV,
1494};
1495
1496static int __init init_ext2_fs(void)
1497{
1498        int err = init_ext2_xattr();
1499        if (err)
1500                return err;
1501        err = init_inodecache();
1502        if (err)
1503                goto out1;
1504        err = register_filesystem(&ext2_fs_type);
1505        if (err)
1506                goto out;
1507        return 0;
1508out:
1509        destroy_inodecache();
1510out1:
1511        exit_ext2_xattr();
1512        return err;
1513}
1514
1515static void __exit exit_ext2_fs(void)
1516{
1517        unregister_filesystem(&ext2_fs_type);
1518        destroy_inodecache();
1519        exit_ext2_xattr();
1520}
1521
1522MODULE_AUTHOR("Remy Card and others");
1523MODULE_DESCRIPTION("Second Extended Filesystem");
1524MODULE_LICENSE("GPL");
1525module_init(init_ext2_fs)
1526module_exit(exit_ext2_fs)
1527