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);
  45static int ext2_freeze(struct super_block *sb);
  46static int ext2_unfreeze(struct super_block *sb);
  47
  48void ext2_error(struct super_block *sb, const char *function,
  49                const char *fmt, ...)
  50{
  51        struct va_format vaf;
  52        va_list args;
  53        struct ext2_sb_info *sbi = EXT2_SB(sb);
  54        struct ext2_super_block *es = sbi->s_es;
  55
  56        if (!(sb->s_flags & MS_RDONLY)) {
  57                spin_lock(&sbi->s_lock);
  58                sbi->s_mount_state |= EXT2_ERROR_FS;
  59                es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  60                spin_unlock(&sbi->s_lock);
  61                ext2_sync_super(sb, es, 1);
  62        }
  63
  64        va_start(args, fmt);
  65
  66        vaf.fmt = fmt;
  67        vaf.va = &args;
  68
  69        printk(KERN_CRIT "EXT2-fs (%s): error: %s: %pV\n",
  70               sb->s_id, function, &vaf);
  71
  72        va_end(args);
  73
  74        if (test_opt(sb, ERRORS_PANIC))
  75                panic("EXT2-fs: panic from previous error\n");
  76        if (test_opt(sb, ERRORS_RO)) {
  77                ext2_msg(sb, KERN_CRIT,
  78                             "error: remounting filesystem read-only");
  79                sb->s_flags |= MS_RDONLY;
  80        }
  81}
  82
  83void ext2_msg(struct super_block *sb, const char *prefix,
  84                const char *fmt, ...)
  85{
  86        struct va_format vaf;
  87        va_list args;
  88
  89        va_start(args, fmt);
  90
  91        vaf.fmt = fmt;
  92        vaf.va = &args;
  93
  94        printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
  95
  96        va_end(args);
  97}
  98
  99/*
 100 * This must be called with sbi->s_lock held.
 101 */
 102void ext2_update_dynamic_rev(struct super_block *sb)
 103{
 104        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
 105
 106        if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
 107                return;
 108
 109        ext2_msg(sb, KERN_WARNING,
 110                     "warning: updating to rev %d because of "
 111                     "new feature flag, running e2fsck is recommended",
 112                     EXT2_DYNAMIC_REV);
 113
 114        es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
 115        es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 116        es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 117        /* leave es->s_feature_*compat flags alone */
 118        /* es->s_uuid will be set by e2fsck if empty */
 119
 120        /*
 121         * The rest of the superblock fields should be zero, and if not it
 122         * means they are likely already in use, so leave them alone.  We
 123         * can leave it up to e2fsck to clean up any inconsistencies there.
 124         */
 125}
 126
 127static void ext2_put_super (struct super_block * sb)
 128{
 129        int db_count;
 130        int i;
 131        struct ext2_sb_info *sbi = EXT2_SB(sb);
 132
 133        dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 134
 135        ext2_xattr_put_super(sb);
 136        if (!(sb->s_flags & MS_RDONLY)) {
 137                struct ext2_super_block *es = sbi->s_es;
 138
 139                spin_lock(&sbi->s_lock);
 140                es->s_state = cpu_to_le16(sbi->s_mount_state);
 141                spin_unlock(&sbi->s_lock);
 142                ext2_sync_super(sb, es, 1);
 143        }
 144        db_count = sbi->s_gdb_count;
 145        for (i = 0; i < db_count; i++)
 146                if (sbi->s_group_desc[i])
 147                        brelse (sbi->s_group_desc[i]);
 148        kfree(sbi->s_group_desc);
 149        kfree(sbi->s_debts);
 150        percpu_counter_destroy(&sbi->s_freeblocks_counter);
 151        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 152        percpu_counter_destroy(&sbi->s_dirs_counter);
 153        brelse (sbi->s_sbh);
 154        sb->s_fs_info = NULL;
 155        kfree(sbi->s_blockgroup_lock);
 156        kfree(sbi);
 157}
 158
 159static struct kmem_cache * ext2_inode_cachep;
 160
 161static struct inode *ext2_alloc_inode(struct super_block *sb)
 162{
 163        struct ext2_inode_info *ei;
 164        ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 165        if (!ei)
 166                return NULL;
 167        ei->i_block_alloc_info = NULL;
 168        ei->vfs_inode.i_version = 1;
 169        return &ei->vfs_inode;
 170}
 171
 172static void ext2_i_callback(struct rcu_head *head)
 173{
 174        struct inode *inode = container_of(head, struct inode, i_rcu);
 175        kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 176}
 177
 178static void ext2_destroy_inode(struct inode *inode)
 179{
 180        call_rcu(&inode->i_rcu, ext2_i_callback);
 181}
 182
 183static void init_once(void *foo)
 184{
 185        struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 186
 187        rwlock_init(&ei->i_meta_lock);
 188#ifdef CONFIG_EXT2_FS_XATTR
 189        init_rwsem(&ei->xattr_sem);
 190#endif
 191        mutex_init(&ei->truncate_mutex);
 192        inode_init_once(&ei->vfs_inode);
 193}
 194
 195static int init_inodecache(void)
 196{
 197        ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 198                                             sizeof(struct ext2_inode_info),
 199                                             0, (SLAB_RECLAIM_ACCOUNT|
 200                                                SLAB_MEM_SPREAD),
 201                                             init_once);
 202        if (ext2_inode_cachep == NULL)
 203                return -ENOMEM;
 204        return 0;
 205}
 206
 207static void destroy_inodecache(void)
 208{
 209        /*
 210         * Make sure all delayed rcu free inodes are flushed before we
 211         * destroy cache.
 212         */
 213        rcu_barrier();
 214        kmem_cache_destroy(ext2_inode_cachep);
 215}
 216
 217static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 218{
 219        struct super_block *sb = root->d_sb;
 220        struct ext2_sb_info *sbi = EXT2_SB(sb);
 221        struct ext2_super_block *es = sbi->s_es;
 222        unsigned long def_mount_opts;
 223
 224        spin_lock(&sbi->s_lock);
 225        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 226
 227        if (sbi->s_sb_block != 1)
 228                seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 229        if (test_opt(sb, MINIX_DF))
 230                seq_puts(seq, ",minixdf");
 231        if (test_opt(sb, GRPID))
 232                seq_puts(seq, ",grpid");
 233        if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 234                seq_puts(seq, ",nogrpid");
 235        if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 236            le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 237                seq_printf(seq, ",resuid=%u",
 238                                from_kuid_munged(&init_user_ns, sbi->s_resuid));
 239        }
 240        if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 241            le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 242                seq_printf(seq, ",resgid=%u",
 243                                from_kgid_munged(&init_user_ns, sbi->s_resgid));
 244        }
 245        if (test_opt(sb, ERRORS_RO)) {
 246                int def_errors = le16_to_cpu(es->s_errors);
 247
 248                if (def_errors == EXT2_ERRORS_PANIC ||
 249                    def_errors == EXT2_ERRORS_CONTINUE) {
 250                        seq_puts(seq, ",errors=remount-ro");
 251                }
 252        }
 253        if (test_opt(sb, ERRORS_CONT))
 254                seq_puts(seq, ",errors=continue");
 255        if (test_opt(sb, ERRORS_PANIC))
 256                seq_puts(seq, ",errors=panic");
 257        if (test_opt(sb, NO_UID32))
 258                seq_puts(seq, ",nouid32");
 259        if (test_opt(sb, DEBUG))
 260                seq_puts(seq, ",debug");
 261        if (test_opt(sb, OLDALLOC))
 262                seq_puts(seq, ",oldalloc");
 263
 264#ifdef CONFIG_EXT2_FS_XATTR
 265        if (test_opt(sb, XATTR_USER))
 266                seq_puts(seq, ",user_xattr");
 267        if (!test_opt(sb, XATTR_USER) &&
 268            (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 269                seq_puts(seq, ",nouser_xattr");
 270        }
 271#endif
 272
 273#ifdef CONFIG_EXT2_FS_POSIX_ACL
 274        if (test_opt(sb, POSIX_ACL))
 275                seq_puts(seq, ",acl");
 276        if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 277                seq_puts(seq, ",noacl");
 278#endif
 279
 280        if (test_opt(sb, NOBH))
 281                seq_puts(seq, ",nobh");
 282
 283#if defined(CONFIG_QUOTA)
 284        if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 285                seq_puts(seq, ",usrquota");
 286
 287        if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 288                seq_puts(seq, ",grpquota");
 289#endif
 290
 291#if defined(CONFIG_EXT2_FS_XIP)
 292        if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 293                seq_puts(seq, ",xip");
 294#endif
 295
 296        if (!test_opt(sb, RESERVATION))
 297                seq_puts(seq, ",noreservation");
 298
 299        spin_unlock(&sbi->s_lock);
 300        return 0;
 301}
 302
 303#ifdef CONFIG_QUOTA
 304static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 305static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 306#endif
 307
 308static const struct super_operations ext2_sops = {
 309        .alloc_inode    = ext2_alloc_inode,
 310        .destroy_inode  = ext2_destroy_inode,
 311        .write_inode    = ext2_write_inode,
 312        .evict_inode    = ext2_evict_inode,
 313        .put_super      = ext2_put_super,
 314        .sync_fs        = ext2_sync_fs,
 315        .freeze_fs      = ext2_freeze,
 316        .unfreeze_fs    = ext2_unfreeze,
 317        .statfs         = ext2_statfs,
 318        .remount_fs     = ext2_remount,
 319        .show_options   = ext2_show_options,
 320#ifdef CONFIG_QUOTA
 321        .quota_read     = ext2_quota_read,
 322        .quota_write    = ext2_quota_write,
 323#endif
 324};
 325
 326static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 327                u64 ino, u32 generation)
 328{
 329        struct inode *inode;
 330
 331        if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 332                return ERR_PTR(-ESTALE);
 333        if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 334                return ERR_PTR(-ESTALE);
 335
 336        /*
 337         * ext2_iget isn't quite right if the inode is currently unallocated!
 338         * However ext2_iget currently does appropriate checks to handle stale
 339         * inodes so everything is OK.
 340         */
 341        inode = ext2_iget(sb, ino);
 342        if (IS_ERR(inode))
 343                return ERR_CAST(inode);
 344        if (generation && inode->i_generation != generation) {
 345                /* we didn't find the right inode.. */
 346                iput(inode);
 347                return ERR_PTR(-ESTALE);
 348        }
 349        return inode;
 350}
 351
 352static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 353                int fh_len, int fh_type)
 354{
 355        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 356                                    ext2_nfs_get_inode);
 357}
 358
 359static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 360                int fh_len, int fh_type)
 361{
 362        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 363                                    ext2_nfs_get_inode);
 364}
 365
 366static const struct export_operations ext2_export_ops = {
 367        .fh_to_dentry = ext2_fh_to_dentry,
 368        .fh_to_parent = ext2_fh_to_parent,
 369        .get_parent = ext2_get_parent,
 370};
 371
 372static unsigned long get_sb_block(void **data)
 373{
 374        unsigned long   sb_block;
 375        char            *options = (char *) *data;
 376
 377        if (!options || strncmp(options, "sb=", 3) != 0)
 378                return 1;       /* Default location */
 379        options += 3;
 380        sb_block = simple_strtoul(options, &options, 0);
 381        if (*options && *options != ',') {
 382                printk("EXT2-fs: Invalid sb specification: %s\n",
 383                       (char *) *data);
 384                return 1;
 385        }
 386        if (*options == ',')
 387                options++;
 388        *data = (void *) options;
 389        return sb_block;
 390}
 391
 392enum {
 393        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 394        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 395        Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 396        Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 397        Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota,
 398        Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 399};
 400
 401static const match_table_t tokens = {
 402        {Opt_bsd_df, "bsddf"},
 403        {Opt_minix_df, "minixdf"},
 404        {Opt_grpid, "grpid"},
 405        {Opt_grpid, "bsdgroups"},
 406        {Opt_nogrpid, "nogrpid"},
 407        {Opt_nogrpid, "sysvgroups"},
 408        {Opt_resgid, "resgid=%u"},
 409        {Opt_resuid, "resuid=%u"},
 410        {Opt_sb, "sb=%u"},
 411        {Opt_err_cont, "errors=continue"},
 412        {Opt_err_panic, "errors=panic"},
 413        {Opt_err_ro, "errors=remount-ro"},
 414        {Opt_nouid32, "nouid32"},
 415        {Opt_nocheck, "check=none"},
 416        {Opt_nocheck, "nocheck"},
 417        {Opt_debug, "debug"},
 418        {Opt_oldalloc, "oldalloc"},
 419        {Opt_orlov, "orlov"},
 420        {Opt_nobh, "nobh"},
 421        {Opt_user_xattr, "user_xattr"},
 422        {Opt_nouser_xattr, "nouser_xattr"},
 423        {Opt_acl, "acl"},
 424        {Opt_noacl, "noacl"},
 425        {Opt_xip, "xip"},
 426        {Opt_grpquota, "grpquota"},
 427        {Opt_ignore, "noquota"},
 428        {Opt_quota, "quota"},
 429        {Opt_usrquota, "usrquota"},
 430        {Opt_reservation, "reservation"},
 431        {Opt_noreservation, "noreservation"},
 432        {Opt_err, NULL}
 433};
 434
 435static int parse_options(char *options, struct super_block *sb)
 436{
 437        char *p;
 438        struct ext2_sb_info *sbi = EXT2_SB(sb);
 439        substring_t args[MAX_OPT_ARGS];
 440        int option;
 441        kuid_t uid;
 442        kgid_t gid;
 443
 444        if (!options)
 445                return 1;
 446
 447        while ((p = strsep (&options, ",")) != NULL) {
 448                int token;
 449                if (!*p)
 450                        continue;
 451
 452                token = match_token(p, tokens, args);
 453                switch (token) {
 454                case Opt_bsd_df:
 455                        clear_opt (sbi->s_mount_opt, MINIX_DF);
 456                        break;
 457                case Opt_minix_df:
 458                        set_opt (sbi->s_mount_opt, MINIX_DF);
 459                        break;
 460                case Opt_grpid:
 461                        set_opt (sbi->s_mount_opt, GRPID);
 462                        break;
 463                case Opt_nogrpid:
 464                        clear_opt (sbi->s_mount_opt, GRPID);
 465                        break;
 466                case Opt_resuid:
 467                        if (match_int(&args[0], &option))
 468                                return 0;
 469                        uid = make_kuid(current_user_ns(), option);
 470                        if (!uid_valid(uid)) {
 471                                ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 472                                return 0;
 473
 474                        }
 475                        sbi->s_resuid = uid;
 476                        break;
 477                case Opt_resgid:
 478                        if (match_int(&args[0], &option))
 479                                return 0;
 480                        gid = make_kgid(current_user_ns(), option);
 481                        if (!gid_valid(gid)) {
 482                                ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 483                                return 0;
 484                        }
 485                        sbi->s_resgid = gid;
 486                        break;
 487                case Opt_sb:
 488                        /* handled by get_sb_block() instead of here */
 489                        /* *sb_block = match_int(&args[0]); */
 490                        break;
 491                case Opt_err_panic:
 492                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 493                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 494                        set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 495                        break;
 496                case Opt_err_ro:
 497                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 498                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 499                        set_opt (sbi->s_mount_opt, ERRORS_RO);
 500                        break;
 501                case Opt_err_cont:
 502                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 503                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 504                        set_opt (sbi->s_mount_opt, ERRORS_CONT);
 505                        break;
 506                case Opt_nouid32:
 507                        set_opt (sbi->s_mount_opt, NO_UID32);
 508                        break;
 509                case Opt_nocheck:
 510                        clear_opt (sbi->s_mount_opt, CHECK);
 511                        break;
 512                case Opt_debug:
 513                        set_opt (sbi->s_mount_opt, DEBUG);
 514                        break;
 515                case Opt_oldalloc:
 516                        set_opt (sbi->s_mount_opt, OLDALLOC);
 517                        break;
 518                case Opt_orlov:
 519                        clear_opt (sbi->s_mount_opt, OLDALLOC);
 520                        break;
 521                case Opt_nobh:
 522                        set_opt (sbi->s_mount_opt, NOBH);
 523                        break;
 524#ifdef CONFIG_EXT2_FS_XATTR
 525                case Opt_user_xattr:
 526                        set_opt (sbi->s_mount_opt, XATTR_USER);
 527                        break;
 528                case Opt_nouser_xattr:
 529                        clear_opt (sbi->s_mount_opt, XATTR_USER);
 530                        break;
 531#else
 532                case Opt_user_xattr:
 533                case Opt_nouser_xattr:
 534                        ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 535                                "not supported");
 536                        break;
 537#endif
 538#ifdef CONFIG_EXT2_FS_POSIX_ACL
 539                case Opt_acl:
 540                        set_opt(sbi->s_mount_opt, POSIX_ACL);
 541                        break;
 542                case Opt_noacl:
 543                        clear_opt(sbi->s_mount_opt, POSIX_ACL);
 544                        break;
 545#else
 546                case Opt_acl:
 547                case Opt_noacl:
 548                        ext2_msg(sb, KERN_INFO,
 549                                "(no)acl options not supported");
 550                        break;
 551#endif
 552                case Opt_xip:
 553#ifdef CONFIG_EXT2_FS_XIP
 554                        set_opt (sbi->s_mount_opt, XIP);
 555#else
 556                        ext2_msg(sb, KERN_INFO, "xip option not supported");
 557#endif
 558                        break;
 559
 560#if defined(CONFIG_QUOTA)
 561                case Opt_quota:
 562                case Opt_usrquota:
 563                        set_opt(sbi->s_mount_opt, USRQUOTA);
 564                        break;
 565
 566                case Opt_grpquota:
 567                        set_opt(sbi->s_mount_opt, GRPQUOTA);
 568                        break;
 569#else
 570                case Opt_quota:
 571                case Opt_usrquota:
 572                case Opt_grpquota:
 573                        ext2_msg(sb, KERN_INFO,
 574                                "quota operations not supported");
 575                        break;
 576#endif
 577
 578                case Opt_reservation:
 579                        set_opt(sbi->s_mount_opt, RESERVATION);
 580                        ext2_msg(sb, KERN_INFO, "reservations ON");
 581                        break;
 582                case Opt_noreservation:
 583                        clear_opt(sbi->s_mount_opt, RESERVATION);
 584                        ext2_msg(sb, KERN_INFO, "reservations OFF");
 585                        break;
 586                case Opt_ignore:
 587                        break;
 588                default:
 589                        return 0;
 590                }
 591        }
 592        return 1;
 593}
 594
 595static int ext2_setup_super (struct super_block * sb,
 596                              struct ext2_super_block * es,
 597                              int read_only)
 598{
 599        int res = 0;
 600        struct ext2_sb_info *sbi = EXT2_SB(sb);
 601
 602        if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 603                ext2_msg(sb, KERN_ERR,
 604                        "error: revision level too high, "
 605                        "forcing read-only mode");
 606                res = MS_RDONLY;
 607        }
 608        if (read_only)
 609                return res;
 610        if (!(sbi->s_mount_state & EXT2_VALID_FS))
 611                ext2_msg(sb, KERN_WARNING,
 612                        "warning: mounting unchecked fs, "
 613                        "running e2fsck is recommended");
 614        else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 615                ext2_msg(sb, KERN_WARNING,
 616                        "warning: mounting fs with errors, "
 617                        "running e2fsck is recommended");
 618        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 619                 le16_to_cpu(es->s_mnt_count) >=
 620                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 621                ext2_msg(sb, KERN_WARNING,
 622                        "warning: maximal mount count reached, "
 623                        "running e2fsck is recommended");
 624        else if (le32_to_cpu(es->s_checkinterval) &&
 625                (le32_to_cpu(es->s_lastcheck) +
 626                        le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 627                ext2_msg(sb, KERN_WARNING,
 628                        "warning: checktime reached, "
 629                        "running e2fsck is recommended");
 630        if (!le16_to_cpu(es->s_max_mnt_count))
 631                es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 632        le16_add_cpu(&es->s_mnt_count, 1);
 633        if (test_opt (sb, DEBUG))
 634                ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 635                        "bpg=%lu, ipg=%lu, mo=%04lx]",
 636                        EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 637                        sbi->s_frag_size,
 638                        sbi->s_groups_count,
 639                        EXT2_BLOCKS_PER_GROUP(sb),
 640                        EXT2_INODES_PER_GROUP(sb),
 641                        sbi->s_mount_opt);
 642        return res;
 643}
 644
 645static int ext2_check_descriptors(struct super_block *sb)
 646{
 647        int i;
 648        struct ext2_sb_info *sbi = EXT2_SB(sb);
 649
 650        ext2_debug ("Checking group descriptors");
 651
 652        for (i = 0; i < sbi->s_groups_count; i++) {
 653                struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 654                ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 655                ext2_fsblk_t last_block;
 656
 657                if (i == sbi->s_groups_count - 1)
 658                        last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 659                else
 660                        last_block = first_block +
 661                                (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 662
 663                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 664                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 665                {
 666                        ext2_error (sb, "ext2_check_descriptors",
 667                                    "Block bitmap for group %d"
 668                                    " not in group (block %lu)!",
 669                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 670                        return 0;
 671                }
 672                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 673                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 674                {
 675                        ext2_error (sb, "ext2_check_descriptors",
 676                                    "Inode bitmap for group %d"
 677                                    " not in group (block %lu)!",
 678                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 679                        return 0;
 680                }
 681                if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 682                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 683                    last_block)
 684                {
 685                        ext2_error (sb, "ext2_check_descriptors",
 686                                    "Inode table for group %d"
 687                                    " not in group (block %lu)!",
 688                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 689                        return 0;
 690                }
 691        }
 692        return 1;
 693}
 694
 695/*
 696 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 697 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 698 * We need to be 1 filesystem block less than the 2^32 sector limit.
 699 */
 700static loff_t ext2_max_size(int bits)
 701{
 702        loff_t res = EXT2_NDIR_BLOCKS;
 703        int meta_blocks;
 704        loff_t upper_limit;
 705
 706        /* This is calculated to be the largest file size for a
 707         * dense, file such that the total number of
 708         * sectors in the file, including data and all indirect blocks,
 709         * does not exceed 2^32 -1
 710         * __u32 i_blocks representing the total number of
 711         * 512 bytes blocks of the file
 712         */
 713        upper_limit = (1LL << 32) - 1;
 714
 715        /* total blocks in file system block size */
 716        upper_limit >>= (bits - 9);
 717
 718
 719        /* indirect blocks */
 720        meta_blocks = 1;
 721        /* double indirect blocks */
 722        meta_blocks += 1 + (1LL << (bits-2));
 723        /* tripple indirect blocks */
 724        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 725
 726        upper_limit -= meta_blocks;
 727        upper_limit <<= bits;
 728
 729        res += 1LL << (bits-2);
 730        res += 1LL << (2*(bits-2));
 731        res += 1LL << (3*(bits-2));
 732        res <<= bits;
 733        if (res > upper_limit)
 734                res = upper_limit;
 735
 736        if (res > MAX_LFS_FILESIZE)
 737                res = MAX_LFS_FILESIZE;
 738
 739        return res;
 740}
 741
 742static unsigned long descriptor_loc(struct super_block *sb,
 743                                    unsigned long logic_sb_block,
 744                                    int nr)
 745{
 746        struct ext2_sb_info *sbi = EXT2_SB(sb);
 747        unsigned long bg, first_meta_bg;
 748        int has_super = 0;
 749        
 750        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 751
 752        if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 753            nr < first_meta_bg)
 754                return (logic_sb_block + nr + 1);
 755        bg = sbi->s_desc_per_block * nr;
 756        if (ext2_bg_has_super(sb, bg))
 757                has_super = 1;
 758
 759        return ext2_group_first_block_no(sb, bg) + has_super;
 760}
 761
 762static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 763{
 764        struct buffer_head * bh;
 765        struct ext2_sb_info * sbi;
 766        struct ext2_super_block * es;
 767        struct inode *root;
 768        unsigned long block;
 769        unsigned long sb_block = get_sb_block(&data);
 770        unsigned long logic_sb_block;
 771        unsigned long offset = 0;
 772        unsigned long def_mount_opts;
 773        long ret = -EINVAL;
 774        int blocksize = BLOCK_SIZE;
 775        int db_count;
 776        int i, j;
 777        __le32 features;
 778        int err;
 779
 780        err = -ENOMEM;
 781        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 782        if (!sbi)
 783                goto failed;
 784
 785        sbi->s_blockgroup_lock =
 786                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 787        if (!sbi->s_blockgroup_lock) {
 788                kfree(sbi);
 789                goto failed;
 790        }
 791        sb->s_fs_info = sbi;
 792        sbi->s_sb_block = sb_block;
 793
 794        spin_lock_init(&sbi->s_lock);
 795
 796        /*
 797         * See what the current blocksize for the device is, and
 798         * use that as the blocksize.  Otherwise (or if the blocksize
 799         * is smaller than the default) use the default.
 800         * This is important for devices that have a hardware
 801         * sectorsize that is larger than the default.
 802         */
 803        blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 804        if (!blocksize) {
 805                ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 806                goto failed_sbi;
 807        }
 808
 809        /*
 810         * If the superblock doesn't start on a hardware sector boundary,
 811         * calculate the offset.  
 812         */
 813        if (blocksize != BLOCK_SIZE) {
 814                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 815                offset = (sb_block*BLOCK_SIZE) % blocksize;
 816        } else {
 817                logic_sb_block = sb_block;
 818        }
 819
 820        if (!(bh = sb_bread(sb, logic_sb_block))) {
 821                ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 822                goto failed_sbi;
 823        }
 824        /*
 825         * Note: s_es must be initialized as soon as possible because
 826         *       some ext2 macro-instructions depend on its value
 827         */
 828        es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 829        sbi->s_es = es;
 830        sb->s_magic = le16_to_cpu(es->s_magic);
 831
 832        if (sb->s_magic != EXT2_SUPER_MAGIC)
 833                goto cantfind_ext2;
 834
 835        /* Set defaults before we parse the mount options */
 836        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 837        if (def_mount_opts & EXT2_DEFM_DEBUG)
 838                set_opt(sbi->s_mount_opt, DEBUG);
 839        if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 840                set_opt(sbi->s_mount_opt, GRPID);
 841        if (def_mount_opts & EXT2_DEFM_UID16)
 842                set_opt(sbi->s_mount_opt, NO_UID32);
 843#ifdef CONFIG_EXT2_FS_XATTR
 844        if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 845                set_opt(sbi->s_mount_opt, XATTR_USER);
 846#endif
 847#ifdef CONFIG_EXT2_FS_POSIX_ACL
 848        if (def_mount_opts & EXT2_DEFM_ACL)
 849                set_opt(sbi->s_mount_opt, POSIX_ACL);
 850#endif
 851        
 852        if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 853                set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 854        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 855                set_opt(sbi->s_mount_opt, ERRORS_CONT);
 856        else
 857                set_opt(sbi->s_mount_opt, ERRORS_RO);
 858
 859        sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 860        sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 861        
 862        set_opt(sbi->s_mount_opt, RESERVATION);
 863
 864        if (!parse_options((char *) data, sb))
 865                goto failed_mount;
 866
 867        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 868                ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 869                 MS_POSIXACL : 0);
 870
 871        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 872                                    EXT2_MOUNT_XIP if not */
 873
 874        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 875            (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 876             EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 877             EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 878                ext2_msg(sb, KERN_WARNING,
 879                        "warning: feature flags set on rev 0 fs, "
 880                        "running e2fsck is recommended");
 881        /*
 882         * Check feature flags regardless of the revision level, since we
 883         * previously didn't change the revision level when setting the flags,
 884         * so there is a chance incompat flags are set on a rev 0 filesystem.
 885         */
 886        features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 887        if (features) {
 888                ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 889                       "unsupported optional features (%x)",
 890                        le32_to_cpu(features));
 891                goto failed_mount;
 892        }
 893        if (!(sb->s_flags & MS_RDONLY) &&
 894            (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 895                ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 896                       "unsupported optional features (%x)",
 897                       le32_to_cpu(features));
 898                goto failed_mount;
 899        }
 900
 901        blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 902
 903        if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
 904                if (!silent)
 905                        ext2_msg(sb, KERN_ERR,
 906                                "error: unsupported blocksize for xip");
 907                goto failed_mount;
 908        }
 909
 910        /* If the blocksize doesn't match, re-read the thing.. */
 911        if (sb->s_blocksize != blocksize) {
 912                brelse(bh);
 913
 914                if (!sb_set_blocksize(sb, blocksize)) {
 915                        ext2_msg(sb, KERN_ERR,
 916                                "error: bad blocksize %d", blocksize);
 917                        goto failed_sbi;
 918                }
 919
 920                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 921                offset = (sb_block*BLOCK_SIZE) % blocksize;
 922                bh = sb_bread(sb, logic_sb_block);
 923                if(!bh) {
 924                        ext2_msg(sb, KERN_ERR, "error: couldn't read"
 925                                "superblock on 2nd try");
 926                        goto failed_sbi;
 927                }
 928                es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 929                sbi->s_es = es;
 930                if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 931                        ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 932                        goto failed_mount;
 933                }
 934        }
 935
 936        sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 937        sb->s_max_links = EXT2_LINK_MAX;
 938
 939        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 940                sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 941                sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 942        } else {
 943                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 944                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 945                if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 946                    !is_power_of_2(sbi->s_inode_size) ||
 947                    (sbi->s_inode_size > blocksize)) {
 948                        ext2_msg(sb, KERN_ERR,
 949                                "error: unsupported inode size: %d",
 950                                sbi->s_inode_size);
 951                        goto failed_mount;
 952                }
 953        }
 954
 955        sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 956                                   le32_to_cpu(es->s_log_frag_size);
 957        if (sbi->s_frag_size == 0)
 958                goto cantfind_ext2;
 959        sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 960
 961        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 962        sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 963        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 964
 965        if (EXT2_INODE_SIZE(sb) == 0)
 966                goto cantfind_ext2;
 967        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 968        if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 969                goto cantfind_ext2;
 970        sbi->s_itb_per_group = sbi->s_inodes_per_group /
 971                                        sbi->s_inodes_per_block;
 972        sbi->s_desc_per_block = sb->s_blocksize /
 973                                        sizeof (struct ext2_group_desc);
 974        sbi->s_sbh = bh;
 975        sbi->s_mount_state = le16_to_cpu(es->s_state);
 976        sbi->s_addr_per_block_bits =
 977                ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 978        sbi->s_desc_per_block_bits =
 979                ilog2 (EXT2_DESC_PER_BLOCK(sb));
 980
 981        if (sb->s_magic != EXT2_SUPER_MAGIC)
 982                goto cantfind_ext2;
 983
 984        if (sb->s_blocksize != bh->b_size) {
 985                if (!silent)
 986                        ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
 987                goto failed_mount;
 988        }
 989
 990        if (sb->s_blocksize != sbi->s_frag_size) {
 991                ext2_msg(sb, KERN_ERR,
 992                        "error: fragsize %lu != blocksize %lu"
 993                        "(not supported yet)",
 994                        sbi->s_frag_size, sb->s_blocksize);
 995                goto failed_mount;
 996        }
 997
 998        if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 999                ext2_msg(sb, KERN_ERR,
1000                        "error: #blocks per group too big: %lu",
1001                        sbi->s_blocks_per_group);
1002                goto failed_mount;
1003        }
1004        if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1005                ext2_msg(sb, KERN_ERR,
1006                        "error: #fragments per group too big: %lu",
1007                        sbi->s_frags_per_group);
1008                goto failed_mount;
1009        }
1010        if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1011                ext2_msg(sb, KERN_ERR,
1012                        "error: #inodes per group too big: %lu",
1013                        sbi->s_inodes_per_group);
1014                goto failed_mount;
1015        }
1016
1017        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1018                goto cantfind_ext2;
1019        sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1020                                le32_to_cpu(es->s_first_data_block) - 1)
1021                                        / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1022        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1023                   EXT2_DESC_PER_BLOCK(sb);
1024        sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1025        if (sbi->s_group_desc == NULL) {
1026                ext2_msg(sb, KERN_ERR, "error: not enough memory");
1027                goto failed_mount;
1028        }
1029        bgl_lock_init(sbi->s_blockgroup_lock);
1030        sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1031        if (!sbi->s_debts) {
1032                ext2_msg(sb, KERN_ERR, "error: not enough memory");
1033                goto failed_mount_group_desc;
1034        }
1035        for (i = 0; i < db_count; i++) {
1036                block = descriptor_loc(sb, logic_sb_block, i);
1037                sbi->s_group_desc[i] = sb_bread(sb, block);
1038                if (!sbi->s_group_desc[i]) {
1039                        for (j = 0; j < i; j++)
1040                                brelse (sbi->s_group_desc[j]);
1041                        ext2_msg(sb, KERN_ERR,
1042                                "error: unable to read group descriptors");
1043                        goto failed_mount_group_desc;
1044                }
1045        }
1046        if (!ext2_check_descriptors (sb)) {
1047                ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1048                goto failed_mount2;
1049        }
1050        sbi->s_gdb_count = db_count;
1051        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1052        spin_lock_init(&sbi->s_next_gen_lock);
1053
1054        /* per fileystem reservation list head & lock */
1055        spin_lock_init(&sbi->s_rsv_window_lock);
1056        sbi->s_rsv_window_root = RB_ROOT;
1057        /*
1058         * Add a single, static dummy reservation to the start of the
1059         * reservation window list --- it gives us a placeholder for
1060         * append-at-start-of-list which makes the allocation logic
1061         * _much_ simpler.
1062         */
1063        sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1064        sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1065        sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1066        sbi->s_rsv_window_head.rsv_goal_size = 0;
1067        ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1068
1069        err = percpu_counter_init(&sbi->s_freeblocks_counter,
1070                                ext2_count_free_blocks(sb));
1071        if (!err) {
1072                err = percpu_counter_init(&sbi->s_freeinodes_counter,
1073                                ext2_count_free_inodes(sb));
1074        }
1075        if (!err) {
1076                err = percpu_counter_init(&sbi->s_dirs_counter,
1077                                ext2_count_dirs(sb));
1078        }
1079        if (err) {
1080                ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1081                goto failed_mount3;
1082        }
1083        /*
1084         * set up enough so that it can read an inode
1085         */
1086        sb->s_op = &ext2_sops;
1087        sb->s_export_op = &ext2_export_ops;
1088        sb->s_xattr = ext2_xattr_handlers;
1089
1090#ifdef CONFIG_QUOTA
1091        sb->dq_op = &dquot_operations;
1092        sb->s_qcop = &dquot_quotactl_ops;
1093#endif
1094
1095        root = ext2_iget(sb, EXT2_ROOT_INO);
1096        if (IS_ERR(root)) {
1097                ret = PTR_ERR(root);
1098                goto failed_mount3;
1099        }
1100        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1101                iput(root);
1102                ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1103                goto failed_mount3;
1104        }
1105
1106        sb->s_root = d_make_root(root);
1107        if (!sb->s_root) {
1108                ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1109                ret = -ENOMEM;
1110                goto failed_mount3;
1111        }
1112        if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1113                ext2_msg(sb, KERN_WARNING,
1114                        "warning: mounting ext3 filesystem as ext2");
1115        if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
1116                sb->s_flags |= MS_RDONLY;
1117        ext2_write_super(sb);
1118        return 0;
1119
1120cantfind_ext2:
1121        if (!silent)
1122                ext2_msg(sb, KERN_ERR,
1123                        "error: can't find an ext2 filesystem on dev %s.",
1124                        sb->s_id);
1125        goto failed_mount;
1126failed_mount3:
1127        percpu_counter_destroy(&sbi->s_freeblocks_counter);
1128        percpu_counter_destroy(&sbi->s_freeinodes_counter);
1129        percpu_counter_destroy(&sbi->s_dirs_counter);
1130failed_mount2:
1131        for (i = 0; i < db_count; i++)
1132                brelse(sbi->s_group_desc[i]);
1133failed_mount_group_desc:
1134        kfree(sbi->s_group_desc);
1135        kfree(sbi->s_debts);
1136failed_mount:
1137        brelse(bh);
1138failed_sbi:
1139        sb->s_fs_info = NULL;
1140        kfree(sbi->s_blockgroup_lock);
1141        kfree(sbi);
1142failed:
1143        return ret;
1144}
1145
1146static void ext2_clear_super_error(struct super_block *sb)
1147{
1148        struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1149
1150        if (buffer_write_io_error(sbh)) {
1151                /*
1152                 * Oh, dear.  A previous attempt to write the
1153                 * superblock failed.  This could happen because the
1154                 * USB device was yanked out.  Or it could happen to
1155                 * be a transient write error and maybe the block will
1156                 * be remapped.  Nothing we can do but to retry the
1157                 * write and hope for the best.
1158                 */
1159                ext2_msg(sb, KERN_ERR,
1160                       "previous I/O error to superblock detected\n");
1161                clear_buffer_write_io_error(sbh);
1162                set_buffer_uptodate(sbh);
1163        }
1164}
1165
1166static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1167                            int wait)
1168{
1169        ext2_clear_super_error(sb);
1170        spin_lock(&EXT2_SB(sb)->s_lock);
1171        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1172        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1173        es->s_wtime = cpu_to_le32(get_seconds());
1174        /* unlock before we do IO */
1175        spin_unlock(&EXT2_SB(sb)->s_lock);
1176        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1177        if (wait)
1178                sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1179}
1180
1181/*
1182 * In the second extended file system, it is not necessary to
1183 * write the super block since we use a mapping of the
1184 * disk super block in a buffer.
1185 *
1186 * However, this function is still used to set the fs valid
1187 * flags to 0.  We need to set this flag to 0 since the fs
1188 * may have been checked while mounted and e2fsck may have
1189 * set s_state to EXT2_VALID_FS after some corrections.
1190 */
1191static int ext2_sync_fs(struct super_block *sb, int wait)
1192{
1193        struct ext2_sb_info *sbi = EXT2_SB(sb);
1194        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1195
1196        /*
1197         * Write quota structures to quota file, sync_blockdev() will write
1198         * them to disk later
1199         */
1200        dquot_writeback_dquots(sb, -1);
1201
1202        spin_lock(&sbi->s_lock);
1203        if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1204                ext2_debug("setting valid to 0\n");
1205                es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1206        }
1207        spin_unlock(&sbi->s_lock);
1208        ext2_sync_super(sb, es, wait);
1209        return 0;
1210}
1211
1212static int ext2_freeze(struct super_block *sb)
1213{
1214        struct ext2_sb_info *sbi = EXT2_SB(sb);
1215
1216        /*
1217         * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1218         * because we have unattached inodes and thus filesystem is not fully
1219         * consistent.
1220         */
1221        if (atomic_long_read(&sb->s_remove_count)) {
1222                ext2_sync_fs(sb, 1);
1223                return 0;
1224        }
1225        /* Set EXT2_FS_VALID flag */
1226        spin_lock(&sbi->s_lock);
1227        sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1228        spin_unlock(&sbi->s_lock);
1229        ext2_sync_super(sb, sbi->s_es, 1);
1230
1231        return 0;
1232}
1233
1234static int ext2_unfreeze(struct super_block *sb)
1235{
1236        /* Just write sb to clear EXT2_VALID_FS flag */
1237        ext2_write_super(sb);
1238
1239        return 0;
1240}
1241
1242void ext2_write_super(struct super_block *sb)
1243{
1244        if (!(sb->s_flags & MS_RDONLY))
1245                ext2_sync_fs(sb, 1);
1246}
1247
1248static int ext2_remount (struct super_block * sb, int * flags, char * data)
1249{
1250        struct ext2_sb_info * sbi = EXT2_SB(sb);
1251        struct ext2_super_block * es;
1252        unsigned long old_mount_opt = sbi->s_mount_opt;
1253        struct ext2_mount_options old_opts;
1254        unsigned long old_sb_flags;
1255        int err;
1256
1257        spin_lock(&sbi->s_lock);
1258
1259        /* Store the old options */
1260        old_sb_flags = sb->s_flags;
1261        old_opts.s_mount_opt = sbi->s_mount_opt;
1262        old_opts.s_resuid = sbi->s_resuid;
1263        old_opts.s_resgid = sbi->s_resgid;
1264
1265        /*
1266         * Allow the "check" option to be passed as a remount option.
1267         */
1268        if (!parse_options(data, sb)) {
1269                err = -EINVAL;
1270                goto restore_opts;
1271        }
1272
1273        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1274                ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1275
1276        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1277                                    EXT2_MOUNT_XIP if not */
1278
1279        if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1280                ext2_msg(sb, KERN_WARNING,
1281                        "warning: unsupported blocksize for xip");
1282                err = -EINVAL;
1283                goto restore_opts;
1284        }
1285
1286        es = sbi->s_es;
1287        if ((sbi->s_mount_opt ^ old_mount_opt) & EXT2_MOUNT_XIP) {
1288                ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1289                         "xip flag with busy inodes while remounting");
1290                sbi->s_mount_opt &= ~EXT2_MOUNT_XIP;
1291                sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP;
1292        }
1293        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
1294                spin_unlock(&sbi->s_lock);
1295                return 0;
1296        }
1297        if (*flags & MS_RDONLY) {
1298                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1299                    !(sbi->s_mount_state & EXT2_VALID_FS)) {
1300                        spin_unlock(&sbi->s_lock);
1301                        return 0;
1302                }
1303
1304                /*
1305                 * OK, we are remounting a valid rw partition rdonly, so set
1306                 * the rdonly flag and then mark the partition as valid again.
1307                 */
1308                es->s_state = cpu_to_le16(sbi->s_mount_state);
1309                es->s_mtime = cpu_to_le32(get_seconds());
1310                spin_unlock(&sbi->s_lock);
1311
1312                err = dquot_suspend(sb, -1);
1313                if (err < 0) {
1314                        spin_lock(&sbi->s_lock);
1315                        goto restore_opts;
1316                }
1317
1318                ext2_sync_super(sb, es, 1);
1319        } else {
1320                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1321                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
1322                if (ret) {
1323                        ext2_msg(sb, KERN_WARNING,
1324                                "warning: couldn't remount RDWR because of "
1325                                "unsupported optional features (%x).",
1326                                le32_to_cpu(ret));
1327                        err = -EROFS;
1328                        goto restore_opts;
1329                }
1330                /*
1331                 * Mounting a RDONLY partition read-write, so reread and
1332                 * store the current valid flag.  (It may have been changed
1333                 * by e2fsck since we originally mounted the partition.)
1334                 */
1335                sbi->s_mount_state = le16_to_cpu(es->s_state);
1336                if (!ext2_setup_super (sb, es, 0))
1337                        sb->s_flags &= ~MS_RDONLY;
1338                spin_unlock(&sbi->s_lock);
1339
1340                ext2_write_super(sb);
1341
1342                dquot_resume(sb, -1);
1343        }
1344
1345        return 0;
1346restore_opts:
1347        sbi->s_mount_opt = old_opts.s_mount_opt;
1348        sbi->s_resuid = old_opts.s_resuid;
1349        sbi->s_resgid = old_opts.s_resgid;
1350        sb->s_flags = old_sb_flags;
1351        spin_unlock(&sbi->s_lock);
1352        return err;
1353}
1354
1355static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1356{
1357        struct super_block *sb = dentry->d_sb;
1358        struct ext2_sb_info *sbi = EXT2_SB(sb);
1359        struct ext2_super_block *es = sbi->s_es;
1360        u64 fsid;
1361
1362        spin_lock(&sbi->s_lock);
1363
1364        if (test_opt (sb, MINIX_DF))
1365                sbi->s_overhead_last = 0;
1366        else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1367                unsigned long i, overhead = 0;
1368                smp_rmb();
1369
1370                /*
1371                 * Compute the overhead (FS structures). This is constant
1372                 * for a given filesystem unless the number of block groups
1373                 * changes so we cache the previous value until it does.
1374                 */
1375
1376                /*
1377                 * All of the blocks before first_data_block are
1378                 * overhead
1379                 */
1380                overhead = le32_to_cpu(es->s_first_data_block);
1381
1382                /*
1383                 * Add the overhead attributed to the superblock and
1384                 * block group descriptors.  If the sparse superblocks
1385                 * feature is turned on, then not all groups have this.
1386                 */
1387                for (i = 0; i < sbi->s_groups_count; i++)
1388                        overhead += ext2_bg_has_super(sb, i) +
1389                                ext2_bg_num_gdb(sb, i);
1390
1391                /*
1392                 * Every block group has an inode bitmap, a block
1393                 * bitmap, and an inode table.
1394                 */
1395                overhead += (sbi->s_groups_count *
1396                             (2 + sbi->s_itb_per_group));
1397                sbi->s_overhead_last = overhead;
1398                smp_wmb();
1399                sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1400        }
1401
1402        buf->f_type = EXT2_SUPER_MAGIC;
1403        buf->f_bsize = sb->s_blocksize;
1404        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1405        buf->f_bfree = ext2_count_free_blocks(sb);
1406        es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1407        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1408        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1409                buf->f_bavail = 0;
1410        buf->f_files = le32_to_cpu(es->s_inodes_count);
1411        buf->f_ffree = ext2_count_free_inodes(sb);
1412        es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1413        buf->f_namelen = EXT2_NAME_LEN;
1414        fsid = le64_to_cpup((void *)es->s_uuid) ^
1415               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1416        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1417        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1418        spin_unlock(&sbi->s_lock);
1419        return 0;
1420}
1421
1422static struct dentry *ext2_mount(struct file_system_type *fs_type,
1423        int flags, const char *dev_name, void *data)
1424{
1425        return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1426}
1427
1428#ifdef CONFIG_QUOTA
1429
1430/* Read data from quotafile - avoid pagecache and such because we cannot afford
1431 * acquiring the locks... As quota files are never truncated and quota code
1432 * itself serializes the operations (and no one else should touch the files)
1433 * we don't have to be afraid of races */
1434static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1435                               size_t len, loff_t off)
1436{
1437        struct inode *inode = sb_dqopt(sb)->files[type];
1438        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1439        int err = 0;
1440        int offset = off & (sb->s_blocksize - 1);
1441        int tocopy;
1442        size_t toread;
1443        struct buffer_head tmp_bh;
1444        struct buffer_head *bh;
1445        loff_t i_size = i_size_read(inode);
1446
1447        if (off > i_size)
1448                return 0;
1449        if (off+len > i_size)
1450                len = i_size-off;
1451        toread = len;
1452        while (toread > 0) {
1453                tocopy = sb->s_blocksize - offset < toread ?
1454                                sb->s_blocksize - offset : toread;
1455
1456                tmp_bh.b_state = 0;
1457                tmp_bh.b_size = sb->s_blocksize;
1458                err = ext2_get_block(inode, blk, &tmp_bh, 0);
1459                if (err < 0)
1460                        return err;
1461                if (!buffer_mapped(&tmp_bh))    /* A hole? */
1462                        memset(data, 0, tocopy);
1463                else {
1464                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1465                        if (!bh)
1466                                return -EIO;
1467                        memcpy(data, bh->b_data+offset, tocopy);
1468                        brelse(bh);
1469                }
1470                offset = 0;
1471                toread -= tocopy;
1472                data += tocopy;
1473                blk++;
1474        }
1475        return len;
1476}
1477
1478/* Write to quotafile */
1479static ssize_t ext2_quota_write(struct super_block *sb, int type,
1480                                const char *data, size_t len, loff_t off)
1481{
1482        struct inode *inode = sb_dqopt(sb)->files[type];
1483        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1484        int err = 0;
1485        int offset = off & (sb->s_blocksize - 1);
1486        int tocopy;
1487        size_t towrite = len;
1488        struct buffer_head tmp_bh;
1489        struct buffer_head *bh;
1490
1491        while (towrite > 0) {
1492                tocopy = sb->s_blocksize - offset < towrite ?
1493                                sb->s_blocksize - offset : towrite;
1494
1495                tmp_bh.b_state = 0;
1496                err = ext2_get_block(inode, blk, &tmp_bh, 1);
1497                if (err < 0)
1498                        goto out;
1499                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1500                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1501                else
1502                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
1503                if (!bh) {
1504                        err = -EIO;
1505                        goto out;
1506                }
1507                lock_buffer(bh);
1508                memcpy(bh->b_data+offset, data, tocopy);
1509                flush_dcache_page(bh->b_page);
1510                set_buffer_uptodate(bh);
1511                mark_buffer_dirty(bh);
1512                unlock_buffer(bh);
1513                brelse(bh);
1514                offset = 0;
1515                towrite -= tocopy;
1516                data += tocopy;
1517                blk++;
1518        }
1519out:
1520        if (len == towrite)
1521                return err;
1522        if (inode->i_size < off+len-towrite)
1523                i_size_write(inode, off+len-towrite);
1524        inode->i_version++;
1525        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1526        mark_inode_dirty(inode);
1527        return len - towrite;
1528}
1529
1530#endif
1531
1532static struct file_system_type ext2_fs_type = {
1533        .owner          = THIS_MODULE,
1534        .name           = "ext2",
1535        .mount          = ext2_mount,
1536        .kill_sb        = kill_block_super,
1537        .fs_flags       = FS_REQUIRES_DEV,
1538};
1539
1540static int __init init_ext2_fs(void)
1541{
1542        int err = init_ext2_xattr();
1543        if (err)
1544                return err;
1545        err = init_inodecache();
1546        if (err)
1547                goto out1;
1548        err = register_filesystem(&ext2_fs_type);
1549        if (err)
1550                goto out;
1551        return 0;
1552out:
1553        destroy_inodecache();
1554out1:
1555        exit_ext2_xattr();
1556        return err;
1557}
1558
1559static void __exit exit_ext2_fs(void)
1560{
1561        unregister_filesystem(&ext2_fs_type);
1562        destroy_inodecache();
1563        exit_ext2_xattr();
1564}
1565
1566MODULE_AUTHOR("Remy Card and others");
1567MODULE_DESCRIPTION("Second Extended Filesystem");
1568MODULE_LICENSE("GPL");
1569module_init(init_ext2_fs)
1570module_exit(exit_ext2_fs)
1571
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