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