Showing error 918

User: Jiri Slaby
Error type: Leaving function in locked state
Error type description: Some lock is not unlocked on all paths of a function, so it is leaked
File location: fs/ext2/super.c
Line in file: 1387
Project: Linux Kernel
Project version: 2.6.28
Confirmation: Fixed by a069e9cee1dba2f847839d325f46ce6976ed1b76
Tools: Stanse (1.2)
Entered: 2012-03-02 21:35:17 UTC


Source:

   1/*
   2 *  linux/fs/ext2/super.c
   3 *
   4 * Copyright (C) 1992, 1993, 1994, 1995
   5 * Remy Card (card@masi.ibp.fr)
   6 * Laboratoire MASI - Institut Blaise Pascal
   7 * Universite Pierre et Marie Curie (Paris VI)
   8 *
   9 *  from
  10 *
  11 *  linux/fs/minix/inode.c
  12 *
  13 *  Copyright (C) 1991, 1992  Linus Torvalds
  14 *
  15 *  Big-endian to little-endian byte-swapping/bitmaps by
  16 *        David S. Miller (davem@caip.rutgers.edu), 1995
  17 */
  18
  19#include <linux/module.h>
  20#include <linux/string.h>
  21#include <linux/fs.h>
  22#include <linux/slab.h>
  23#include <linux/init.h>
  24#include <linux/blkdev.h>
  25#include <linux/parser.h>
  26#include <linux/random.h>
  27#include <linux/buffer_head.h>
  28#include <linux/exportfs.h>
  29#include <linux/smp_lock.h>
  30#include <linux/vfs.h>
  31#include <linux/seq_file.h>
  32#include <linux/mount.h>
  33#include <linux/log2.h>
  34#include <linux/quotaops.h>
  35#include <asm/uaccess.h>
  36#include "ext2.h"
  37#include "xattr.h"
  38#include "acl.h"
  39#include "xip.h"
  40
  41static void ext2_sync_super(struct super_block *sb,
  42                            struct ext2_super_block *es);
  43static int ext2_remount (struct super_block * sb, int * flags, char * data);
  44static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);
  45
  46void ext2_error (struct super_block * sb, const char * function,
  47                 const char * fmt, ...)
  48{
  49        va_list args;
  50        struct ext2_sb_info *sbi = EXT2_SB(sb);
  51        struct ext2_super_block *es = sbi->s_es;
  52
  53        if (!(sb->s_flags & MS_RDONLY)) {
  54                sbi->s_mount_state |= EXT2_ERROR_FS;
  55                es->s_state |= cpu_to_le16(EXT2_ERROR_FS);
  56                ext2_sync_super(sb, es);
  57        }
  58
  59        va_start(args, fmt);
  60        printk(KERN_CRIT "EXT2-fs error (device %s): %s: ",sb->s_id, function);
  61        vprintk(fmt, args);
  62        printk("\n");
  63        va_end(args);
  64
  65        if (test_opt(sb, ERRORS_PANIC))
  66                panic("EXT2-fs panic from previous error\n");
  67        if (test_opt(sb, ERRORS_RO)) {
  68                printk("Remounting filesystem read-only\n");
  69                sb->s_flags |= MS_RDONLY;
  70        }
  71}
  72
  73void ext2_warning (struct super_block * sb, const char * function,
  74                   const char * fmt, ...)
  75{
  76        va_list args;
  77
  78        va_start(args, fmt);
  79        printk(KERN_WARNING "EXT2-fs warning (device %s): %s: ",
  80               sb->s_id, function);
  81        vprintk(fmt, args);
  82        printk("\n");
  83        va_end(args);
  84}
  85
  86void ext2_update_dynamic_rev(struct super_block *sb)
  87{
  88        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
  89
  90        if (le32_to_cpu(es->s_rev_level) > EXT2_GOOD_OLD_REV)
  91                return;
  92
  93        ext2_warning(sb, __func__,
  94                     "updating to rev %d because of new feature flag, "
  95                     "running e2fsck is recommended",
  96                     EXT2_DYNAMIC_REV);
  97
  98        es->s_first_ino = cpu_to_le32(EXT2_GOOD_OLD_FIRST_INO);
  99        es->s_inode_size = cpu_to_le16(EXT2_GOOD_OLD_INODE_SIZE);
 100        es->s_rev_level = cpu_to_le32(EXT2_DYNAMIC_REV);
 101        /* leave es->s_feature_*compat flags alone */
 102        /* es->s_uuid will be set by e2fsck if empty */
 103
 104        /*
 105         * The rest of the superblock fields should be zero, and if not it
 106         * means they are likely already in use, so leave them alone.  We
 107         * can leave it up to e2fsck to clean up any inconsistencies there.
 108         */
 109}
 110
 111static void ext2_put_super (struct super_block * sb)
 112{
 113        int db_count;
 114        int i;
 115        struct ext2_sb_info *sbi = EXT2_SB(sb);
 116
 117        ext2_xattr_put_super(sb);
 118        if (!(sb->s_flags & MS_RDONLY)) {
 119                struct ext2_super_block *es = sbi->s_es;
 120
 121                es->s_state = cpu_to_le16(sbi->s_mount_state);
 122                ext2_sync_super(sb, es);
 123        }
 124        db_count = sbi->s_gdb_count;
 125        for (i = 0; i < db_count; i++)
 126                if (sbi->s_group_desc[i])
 127                        brelse (sbi->s_group_desc[i]);
 128        kfree(sbi->s_group_desc);
 129        kfree(sbi->s_debts);
 130        percpu_counter_destroy(&sbi->s_freeblocks_counter);
 131        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 132        percpu_counter_destroy(&sbi->s_dirs_counter);
 133        brelse (sbi->s_sbh);
 134        sb->s_fs_info = NULL;
 135        kfree(sbi);
 136
 137        return;
 138}
 139
 140static struct kmem_cache * ext2_inode_cachep;
 141
 142static struct inode *ext2_alloc_inode(struct super_block *sb)
 143{
 144        struct ext2_inode_info *ei;
 145        ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 146        if (!ei)
 147                return NULL;
 148#ifdef CONFIG_EXT2_FS_POSIX_ACL
 149        ei->i_acl = EXT2_ACL_NOT_CACHED;
 150        ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 151#endif
 152        ei->i_block_alloc_info = NULL;
 153        ei->vfs_inode.i_version = 1;
 154        return &ei->vfs_inode;
 155}
 156
 157static void ext2_destroy_inode(struct inode *inode)
 158{
 159        kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 160}
 161
 162static void init_once(void *foo)
 163{
 164        struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 165
 166        rwlock_init(&ei->i_meta_lock);
 167#ifdef CONFIG_EXT2_FS_XATTR
 168        init_rwsem(&ei->xattr_sem);
 169#endif
 170        mutex_init(&ei->truncate_mutex);
 171        inode_init_once(&ei->vfs_inode);
 172}
 173
 174static int init_inodecache(void)
 175{
 176        ext2_inode_cachep = kmem_cache_create("ext2_inode_cache",
 177                                             sizeof(struct ext2_inode_info),
 178                                             0, (SLAB_RECLAIM_ACCOUNT|
 179                                                SLAB_MEM_SPREAD),
 180                                             init_once);
 181        if (ext2_inode_cachep == NULL)
 182                return -ENOMEM;
 183        return 0;
 184}
 185
 186static void destroy_inodecache(void)
 187{
 188        kmem_cache_destroy(ext2_inode_cachep);
 189}
 190
 191static void ext2_clear_inode(struct inode *inode)
 192{
 193        struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info;
 194#ifdef CONFIG_EXT2_FS_POSIX_ACL
 195        struct ext2_inode_info *ei = EXT2_I(inode);
 196
 197        if (ei->i_acl && ei->i_acl != EXT2_ACL_NOT_CACHED) {
 198                posix_acl_release(ei->i_acl);
 199                ei->i_acl = EXT2_ACL_NOT_CACHED;
 200        }
 201        if (ei->i_default_acl && ei->i_default_acl != EXT2_ACL_NOT_CACHED) {
 202                posix_acl_release(ei->i_default_acl);
 203                ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 204        }
 205#endif
 206        ext2_discard_reservation(inode);
 207        EXT2_I(inode)->i_block_alloc_info = NULL;
 208        if (unlikely(rsv))
 209                kfree(rsv);
 210}
 211
 212static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs)
 213{
 214        struct super_block *sb = vfs->mnt_sb;
 215        struct ext2_sb_info *sbi = EXT2_SB(sb);
 216        struct ext2_super_block *es = sbi->s_es;
 217        unsigned long def_mount_opts;
 218
 219        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 220
 221        if (sbi->s_sb_block != 1)
 222                seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 223        if (test_opt(sb, MINIX_DF))
 224                seq_puts(seq, ",minixdf");
 225        if (test_opt(sb, GRPID))
 226                seq_puts(seq, ",grpid");
 227        if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 228                seq_puts(seq, ",nogrpid");
 229        if (sbi->s_resuid != EXT2_DEF_RESUID ||
 230            le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 231                seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 232        }
 233        if (sbi->s_resgid != EXT2_DEF_RESGID ||
 234            le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 235                seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 236        }
 237        if (test_opt(sb, ERRORS_RO)) {
 238                int def_errors = le16_to_cpu(es->s_errors);
 239
 240                if (def_errors == EXT2_ERRORS_PANIC ||
 241                    def_errors == EXT2_ERRORS_CONTINUE) {
 242                        seq_puts(seq, ",errors=remount-ro");
 243                }
 244        }
 245        if (test_opt(sb, ERRORS_CONT))
 246                seq_puts(seq, ",errors=continue");
 247        if (test_opt(sb, ERRORS_PANIC))
 248                seq_puts(seq, ",errors=panic");
 249        if (test_opt(sb, NO_UID32))
 250                seq_puts(seq, ",nouid32");
 251        if (test_opt(sb, DEBUG))
 252                seq_puts(seq, ",debug");
 253        if (test_opt(sb, OLDALLOC))
 254                seq_puts(seq, ",oldalloc");
 255
 256#ifdef CONFIG_EXT2_FS_XATTR
 257        if (test_opt(sb, XATTR_USER))
 258                seq_puts(seq, ",user_xattr");
 259        if (!test_opt(sb, XATTR_USER) &&
 260            (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 261                seq_puts(seq, ",nouser_xattr");
 262        }
 263#endif
 264
 265#ifdef CONFIG_EXT2_FS_POSIX_ACL
 266        if (test_opt(sb, POSIX_ACL))
 267                seq_puts(seq, ",acl");
 268        if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 269                seq_puts(seq, ",noacl");
 270#endif
 271
 272        if (test_opt(sb, NOBH))
 273                seq_puts(seq, ",nobh");
 274
 275#if defined(CONFIG_QUOTA)
 276        if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 277                seq_puts(seq, ",usrquota");
 278
 279        if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 280                seq_puts(seq, ",grpquota");
 281#endif
 282
 283#if defined(CONFIG_EXT2_FS_XIP)
 284        if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 285                seq_puts(seq, ",xip");
 286#endif
 287
 288        if (!test_opt(sb, RESERVATION))
 289                seq_puts(seq, ",noreservation");
 290
 291        return 0;
 292}
 293
 294#ifdef CONFIG_QUOTA
 295static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 296static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 297#endif
 298
 299static const struct super_operations ext2_sops = {
 300        .alloc_inode        = ext2_alloc_inode,
 301        .destroy_inode        = ext2_destroy_inode,
 302        .write_inode        = ext2_write_inode,
 303        .delete_inode        = ext2_delete_inode,
 304        .put_super        = ext2_put_super,
 305        .write_super        = ext2_write_super,
 306        .statfs                = ext2_statfs,
 307        .remount_fs        = ext2_remount,
 308        .clear_inode        = ext2_clear_inode,
 309        .show_options        = ext2_show_options,
 310#ifdef CONFIG_QUOTA
 311        .quota_read        = ext2_quota_read,
 312        .quota_write        = ext2_quota_write,
 313#endif
 314};
 315
 316static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 317                u64 ino, u32 generation)
 318{
 319        struct inode *inode;
 320
 321        if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 322                return ERR_PTR(-ESTALE);
 323        if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 324                return ERR_PTR(-ESTALE);
 325
 326        /* iget isn't really right if the inode is currently unallocated!!
 327         * ext2_read_inode currently does appropriate checks, but
 328         * it might be "neater" to call ext2_get_inode first and check
 329         * if the inode is valid.....
 330         */
 331        inode = ext2_iget(sb, ino);
 332        if (IS_ERR(inode))
 333                return ERR_CAST(inode);
 334        if (generation && inode->i_generation != generation) {
 335                /* we didn't find the right inode.. */
 336                iput(inode);
 337                return ERR_PTR(-ESTALE);
 338        }
 339        return inode;
 340}
 341
 342static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 343                int fh_len, int fh_type)
 344{
 345        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 346                                    ext2_nfs_get_inode);
 347}
 348
 349static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 350                int fh_len, int fh_type)
 351{
 352        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 353                                    ext2_nfs_get_inode);
 354}
 355
 356/* Yes, most of these are left as NULL!!
 357 * A NULL value implies the default, which works with ext2-like file
 358 * systems, but can be improved upon.
 359 * Currently only get_parent is required.
 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,
 431                          struct ext2_sb_info *sbi)
 432{
 433        char * p;
 434        substring_t args[MAX_OPT_ARGS];
 435        int option;
 436
 437        if (!options)
 438                return 1;
 439
 440        while ((p = strsep (&options, ",")) != NULL) {
 441                int token;
 442                if (!*p)
 443                        continue;
 444
 445                token = match_token(p, tokens, args);
 446                switch (token) {
 447                case Opt_bsd_df:
 448                        clear_opt (sbi->s_mount_opt, MINIX_DF);
 449                        break;
 450                case Opt_minix_df:
 451                        set_opt (sbi->s_mount_opt, MINIX_DF);
 452                        break;
 453                case Opt_grpid:
 454                        set_opt (sbi->s_mount_opt, GRPID);
 455                        break;
 456                case Opt_nogrpid:
 457                        clear_opt (sbi->s_mount_opt, GRPID);
 458                        break;
 459                case Opt_resuid:
 460                        if (match_int(&args[0], &option))
 461                                return 0;
 462                        sbi->s_resuid = option;
 463                        break;
 464                case Opt_resgid:
 465                        if (match_int(&args[0], &option))
 466                                return 0;
 467                        sbi->s_resgid = option;
 468                        break;
 469                case Opt_sb:
 470                        /* handled by get_sb_block() instead of here */
 471                        /* *sb_block = match_int(&args[0]); */
 472                        break;
 473                case Opt_err_panic:
 474                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 475                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 476                        set_opt (sbi->s_mount_opt, ERRORS_PANIC);
 477                        break;
 478                case Opt_err_ro:
 479                        clear_opt (sbi->s_mount_opt, ERRORS_CONT);
 480                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 481                        set_opt (sbi->s_mount_opt, ERRORS_RO);
 482                        break;
 483                case Opt_err_cont:
 484                        clear_opt (sbi->s_mount_opt, ERRORS_RO);
 485                        clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
 486                        set_opt (sbi->s_mount_opt, ERRORS_CONT);
 487                        break;
 488                case Opt_nouid32:
 489                        set_opt (sbi->s_mount_opt, NO_UID32);
 490                        break;
 491                case Opt_nocheck:
 492                        clear_opt (sbi->s_mount_opt, CHECK);
 493                        break;
 494                case Opt_debug:
 495                        set_opt (sbi->s_mount_opt, DEBUG);
 496                        break;
 497                case Opt_oldalloc:
 498                        set_opt (sbi->s_mount_opt, OLDALLOC);
 499                        break;
 500                case Opt_orlov:
 501                        clear_opt (sbi->s_mount_opt, OLDALLOC);
 502                        break;
 503                case Opt_nobh:
 504                        set_opt (sbi->s_mount_opt, NOBH);
 505                        break;
 506#ifdef CONFIG_EXT2_FS_XATTR
 507                case Opt_user_xattr:
 508                        set_opt (sbi->s_mount_opt, XATTR_USER);
 509                        break;
 510                case Opt_nouser_xattr:
 511                        clear_opt (sbi->s_mount_opt, XATTR_USER);
 512                        break;
 513#else
 514                case Opt_user_xattr:
 515                case Opt_nouser_xattr:
 516                        printk("EXT2 (no)user_xattr options not supported\n");
 517                        break;
 518#endif
 519#ifdef CONFIG_EXT2_FS_POSIX_ACL
 520                case Opt_acl:
 521                        set_opt(sbi->s_mount_opt, POSIX_ACL);
 522                        break;
 523                case Opt_noacl:
 524                        clear_opt(sbi->s_mount_opt, POSIX_ACL);
 525                        break;
 526#else
 527                case Opt_acl:
 528                case Opt_noacl:
 529                        printk("EXT2 (no)acl options not supported\n");
 530                        break;
 531#endif
 532                case Opt_xip:
 533#ifdef CONFIG_EXT2_FS_XIP
 534                        set_opt (sbi->s_mount_opt, XIP);
 535#else
 536                        printk("EXT2 xip option not supported\n");
 537#endif
 538                        break;
 539
 540#if defined(CONFIG_QUOTA)
 541                case Opt_quota:
 542                case Opt_usrquota:
 543                        set_opt(sbi->s_mount_opt, USRQUOTA);
 544                        break;
 545
 546                case Opt_grpquota:
 547                        set_opt(sbi->s_mount_opt, GRPQUOTA);
 548                        break;
 549#else
 550                case Opt_quota:
 551                case Opt_usrquota:
 552                case Opt_grpquota:
 553                        printk(KERN_ERR
 554                                "EXT2-fs: quota operations not supported.\n");
 555
 556                        break;
 557#endif
 558
 559                case Opt_reservation:
 560                        set_opt(sbi->s_mount_opt, RESERVATION);
 561                        printk("reservations ON\n");
 562                        break;
 563                case Opt_noreservation:
 564                        clear_opt(sbi->s_mount_opt, RESERVATION);
 565                        printk("reservations OFF\n");
 566                        break;
 567                case Opt_ignore:
 568                        break;
 569                default:
 570                        return 0;
 571                }
 572        }
 573        return 1;
 574}
 575
 576static int ext2_setup_super (struct super_block * sb,
 577                              struct ext2_super_block * es,
 578                              int read_only)
 579{
 580        int res = 0;
 581        struct ext2_sb_info *sbi = EXT2_SB(sb);
 582
 583        if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 584                printk ("EXT2-fs warning: revision level too high, "
 585                        "forcing read-only mode\n");
 586                res = MS_RDONLY;
 587        }
 588        if (read_only)
 589                return res;
 590        if (!(sbi->s_mount_state & EXT2_VALID_FS))
 591                printk ("EXT2-fs warning: mounting unchecked fs, "
 592                        "running e2fsck is recommended\n");
 593        else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 594                printk ("EXT2-fs warning: mounting fs with errors, "
 595                        "running e2fsck is recommended\n");
 596        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 597                 le16_to_cpu(es->s_mnt_count) >=
 598                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 599                printk ("EXT2-fs warning: maximal mount count reached, "
 600                        "running e2fsck is recommended\n");
 601        else if (le32_to_cpu(es->s_checkinterval) &&
 602                (le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 603                printk ("EXT2-fs warning: checktime reached, "
 604                        "running e2fsck is recommended\n");
 605        if (!le16_to_cpu(es->s_max_mnt_count))
 606                es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 607        le16_add_cpu(&es->s_mnt_count, 1);
 608        ext2_write_super(sb);
 609        if (test_opt (sb, DEBUG))
 610                printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
 611                        "bpg=%lu, ipg=%lu, mo=%04lx]\n",
 612                        EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 613                        sbi->s_frag_size,
 614                        sbi->s_groups_count,
 615                        EXT2_BLOCKS_PER_GROUP(sb),
 616                        EXT2_INODES_PER_GROUP(sb),
 617                        sbi->s_mount_opt);
 618        return res;
 619}
 620
 621static int ext2_check_descriptors(struct super_block *sb)
 622{
 623        int i;
 624        struct ext2_sb_info *sbi = EXT2_SB(sb);
 625
 626        ext2_debug ("Checking group descriptors");
 627
 628        for (i = 0; i < sbi->s_groups_count; i++) {
 629                struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 630                ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 631                ext2_fsblk_t last_block;
 632
 633                if (i == sbi->s_groups_count - 1)
 634                        last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 635                else
 636                        last_block = first_block +
 637                                (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 638
 639                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 640                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 641                {
 642                        ext2_error (sb, "ext2_check_descriptors",
 643                                    "Block bitmap for group %d"
 644                                    " not in group (block %lu)!",
 645                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 646                        return 0;
 647                }
 648                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 649                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 650                {
 651                        ext2_error (sb, "ext2_check_descriptors",
 652                                    "Inode bitmap for group %d"
 653                                    " not in group (block %lu)!",
 654                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 655                        return 0;
 656                }
 657                if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 658                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 659                    last_block)
 660                {
 661                        ext2_error (sb, "ext2_check_descriptors",
 662                                    "Inode table for group %d"
 663                                    " not in group (block %lu)!",
 664                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 665                        return 0;
 666                }
 667        }
 668        return 1;
 669}
 670
 671/*
 672 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 673 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 674 * We need to be 1 filesystem block less than the 2^32 sector limit.
 675 */
 676static loff_t ext2_max_size(int bits)
 677{
 678        loff_t res = EXT2_NDIR_BLOCKS;
 679        int meta_blocks;
 680        loff_t upper_limit;
 681
 682        /* This is calculated to be the largest file size for a
 683         * dense, file such that the total number of
 684         * sectors in the file, including data and all indirect blocks,
 685         * does not exceed 2^32 -1
 686         * __u32 i_blocks representing the total number of
 687         * 512 bytes blocks of the file
 688         */
 689        upper_limit = (1LL << 32) - 1;
 690
 691        /* total blocks in file system block size */
 692        upper_limit >>= (bits - 9);
 693
 694
 695        /* indirect blocks */
 696        meta_blocks = 1;
 697        /* double indirect blocks */
 698        meta_blocks += 1 + (1LL << (bits-2));
 699        /* tripple indirect blocks */
 700        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 701
 702        upper_limit -= meta_blocks;
 703        upper_limit <<= bits;
 704
 705        res += 1LL << (bits-2);
 706        res += 1LL << (2*(bits-2));
 707        res += 1LL << (3*(bits-2));
 708        res <<= bits;
 709        if (res > upper_limit)
 710                res = upper_limit;
 711
 712        if (res > MAX_LFS_FILESIZE)
 713                res = MAX_LFS_FILESIZE;
 714
 715        return res;
 716}
 717
 718static unsigned long descriptor_loc(struct super_block *sb,
 719                                    unsigned long logic_sb_block,
 720                                    int nr)
 721{
 722        struct ext2_sb_info *sbi = EXT2_SB(sb);
 723        unsigned long bg, first_meta_bg;
 724        int has_super = 0;
 725        
 726        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 727
 728        if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 729            nr < first_meta_bg)
 730                return (logic_sb_block + nr + 1);
 731        bg = sbi->s_desc_per_block * nr;
 732        if (ext2_bg_has_super(sb, bg))
 733                has_super = 1;
 734
 735        return ext2_group_first_block_no(sb, bg) + has_super;
 736}
 737
 738static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 739{
 740        struct buffer_head * bh;
 741        struct ext2_sb_info * sbi;
 742        struct ext2_super_block * es;
 743        struct inode *root;
 744        unsigned long block;
 745        unsigned long sb_block = get_sb_block(&data);
 746        unsigned long logic_sb_block;
 747        unsigned long offset = 0;
 748        unsigned long def_mount_opts;
 749        long ret = -EINVAL;
 750        int blocksize = BLOCK_SIZE;
 751        int db_count;
 752        int i, j;
 753        __le32 features;
 754        int err;
 755
 756        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 757        if (!sbi)
 758                return -ENOMEM;
 759        sb->s_fs_info = sbi;
 760        sbi->s_sb_block = sb_block;
 761
 762        /*
 763         * See what the current blocksize for the device is, and
 764         * use that as the blocksize.  Otherwise (or if the blocksize
 765         * is smaller than the default) use the default.
 766         * This is important for devices that have a hardware
 767         * sectorsize that is larger than the default.
 768         */
 769        blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 770        if (!blocksize) {
 771                printk ("EXT2-fs: unable to set blocksize\n");
 772                goto failed_sbi;
 773        }
 774
 775        /*
 776         * If the superblock doesn't start on a hardware sector boundary,
 777         * calculate the offset.  
 778         */
 779        if (blocksize != BLOCK_SIZE) {
 780                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 781                offset = (sb_block*BLOCK_SIZE) % blocksize;
 782        } else {
 783                logic_sb_block = sb_block;
 784        }
 785
 786        if (!(bh = sb_bread(sb, logic_sb_block))) {
 787                printk ("EXT2-fs: unable to read superblock\n");
 788                goto failed_sbi;
 789        }
 790        /*
 791         * Note: s_es must be initialized as soon as possible because
 792         *       some ext2 macro-instructions depend on its value
 793         */
 794        es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 795        sbi->s_es = es;
 796        sb->s_magic = le16_to_cpu(es->s_magic);
 797
 798        if (sb->s_magic != EXT2_SUPER_MAGIC)
 799                goto cantfind_ext2;
 800
 801        /* Set defaults before we parse the mount options */
 802        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 803        if (def_mount_opts & EXT2_DEFM_DEBUG)
 804                set_opt(sbi->s_mount_opt, DEBUG);
 805        if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 806                set_opt(sbi->s_mount_opt, GRPID);
 807        if (def_mount_opts & EXT2_DEFM_UID16)
 808                set_opt(sbi->s_mount_opt, NO_UID32);
 809#ifdef CONFIG_EXT2_FS_XATTR
 810        if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 811                set_opt(sbi->s_mount_opt, XATTR_USER);
 812#endif
 813#ifdef CONFIG_EXT2_FS_POSIX_ACL
 814        if (def_mount_opts & EXT2_DEFM_ACL)
 815                set_opt(sbi->s_mount_opt, POSIX_ACL);
 816#endif
 817        
 818        if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 819                set_opt(sbi->s_mount_opt, ERRORS_PANIC);
 820        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 821                set_opt(sbi->s_mount_opt, ERRORS_CONT);
 822        else
 823                set_opt(sbi->s_mount_opt, ERRORS_RO);
 824
 825        sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 826        sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
 827        
 828        set_opt(sbi->s_mount_opt, RESERVATION);
 829
 830        if (!parse_options ((char *) data, sbi))
 831                goto failed_mount;
 832
 833        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 834                ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 835                 MS_POSIXACL : 0);
 836
 837        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 838                                    EXT2_MOUNT_XIP if not */
 839
 840        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 841            (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 842             EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 843             EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 844                printk("EXT2-fs warning: feature flags set on rev 0 fs, "
 845                       "running e2fsck is recommended\n");
 846        /*
 847         * Check feature flags regardless of the revision level, since we
 848         * previously didn't change the revision level when setting the flags,
 849         * so there is a chance incompat flags are set on a rev 0 filesystem.
 850         */
 851        features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 852        if (features) {
 853                printk("EXT2-fs: %s: couldn't mount because of "
 854                       "unsupported optional features (%x).\n",
 855                       sb->s_id, le32_to_cpu(features));
 856                goto failed_mount;
 857        }
 858        if (!(sb->s_flags & MS_RDONLY) &&
 859            (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 860                printk("EXT2-fs: %s: couldn't mount RDWR because of "
 861                       "unsupported optional features (%x).\n",
 862                       sb->s_id, le32_to_cpu(features));
 863                goto failed_mount;
 864        }
 865
 866        blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 867
 868        if (ext2_use_xip(sb) && blocksize != PAGE_SIZE) {
 869                if (!silent)
 870                        printk("XIP: Unsupported blocksize\n");
 871                goto failed_mount;
 872        }
 873
 874        /* If the blocksize doesn't match, re-read the thing.. */
 875        if (sb->s_blocksize != blocksize) {
 876                brelse(bh);
 877
 878                if (!sb_set_blocksize(sb, blocksize)) {
 879                        printk(KERN_ERR "EXT2-fs: blocksize too small for device.\n");
 880                        goto failed_sbi;
 881                }
 882
 883                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 884                offset = (sb_block*BLOCK_SIZE) % blocksize;
 885                bh = sb_bread(sb, logic_sb_block);
 886                if(!bh) {
 887                        printk("EXT2-fs: Couldn't read superblock on "
 888                               "2nd try.\n");
 889                        goto failed_sbi;
 890                }
 891                es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 892                sbi->s_es = es;
 893                if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 894                        printk ("EXT2-fs: Magic mismatch, very weird !\n");
 895                        goto failed_mount;
 896                }
 897        }
 898
 899        sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 900
 901        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 902                sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
 903                sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
 904        } else {
 905                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
 906                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
 907                if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
 908                    !is_power_of_2(sbi->s_inode_size) ||
 909                    (sbi->s_inode_size > blocksize)) {
 910                        printk ("EXT2-fs: unsupported inode size: %d\n",
 911                                sbi->s_inode_size);
 912                        goto failed_mount;
 913                }
 914        }
 915
 916        sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
 917                                   le32_to_cpu(es->s_log_frag_size);
 918        if (sbi->s_frag_size == 0)
 919                goto cantfind_ext2;
 920        sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
 921
 922        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
 923        sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
 924        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
 925
 926        if (EXT2_INODE_SIZE(sb) == 0)
 927                goto cantfind_ext2;
 928        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
 929        if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
 930                goto cantfind_ext2;
 931        sbi->s_itb_per_group = sbi->s_inodes_per_group /
 932                                        sbi->s_inodes_per_block;
 933        sbi->s_desc_per_block = sb->s_blocksize /
 934                                        sizeof (struct ext2_group_desc);
 935        sbi->s_sbh = bh;
 936        sbi->s_mount_state = le16_to_cpu(es->s_state);
 937        sbi->s_addr_per_block_bits =
 938                ilog2 (EXT2_ADDR_PER_BLOCK(sb));
 939        sbi->s_desc_per_block_bits =
 940                ilog2 (EXT2_DESC_PER_BLOCK(sb));
 941
 942        if (sb->s_magic != EXT2_SUPER_MAGIC)
 943                goto cantfind_ext2;
 944
 945        if (sb->s_blocksize != bh->b_size) {
 946                if (!silent)
 947                        printk ("VFS: Unsupported blocksize on dev "
 948                                "%s.\n", sb->s_id);
 949                goto failed_mount;
 950        }
 951
 952        if (sb->s_blocksize != sbi->s_frag_size) {
 953                printk ("EXT2-fs: fragsize %lu != blocksize %lu (not supported yet)\n",
 954                        sbi->s_frag_size, sb->s_blocksize);
 955                goto failed_mount;
 956        }
 957
 958        if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
 959                printk ("EXT2-fs: #blocks per group too big: %lu\n",
 960                        sbi->s_blocks_per_group);
 961                goto failed_mount;
 962        }
 963        if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
 964                printk ("EXT2-fs: #fragments per group too big: %lu\n",
 965                        sbi->s_frags_per_group);
 966                goto failed_mount;
 967        }
 968        if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
 969                printk ("EXT2-fs: #inodes per group too big: %lu\n",
 970                        sbi->s_inodes_per_group);
 971                goto failed_mount;
 972        }
 973
 974        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
 975                goto cantfind_ext2;
 976         sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
 977                                 le32_to_cpu(es->s_first_data_block) - 1)
 978                                         / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
 979        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
 980                   EXT2_DESC_PER_BLOCK(sb);
 981        sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
 982        if (sbi->s_group_desc == NULL) {
 983                printk ("EXT2-fs: not enough memory\n");
 984                goto failed_mount;
 985        }
 986        bgl_lock_init(&sbi->s_blockgroup_lock);
 987        sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
 988        if (!sbi->s_debts) {
 989                printk ("EXT2-fs: not enough memory\n");
 990                goto failed_mount_group_desc;
 991        }
 992        for (i = 0; i < db_count; i++) {
 993                block = descriptor_loc(sb, logic_sb_block, i);
 994                sbi->s_group_desc[i] = sb_bread(sb, block);
 995                if (!sbi->s_group_desc[i]) {
 996                        for (j = 0; j < i; j++)
 997                                brelse (sbi->s_group_desc[j]);
 998                        printk ("EXT2-fs: unable to read group descriptors\n");
 999                        goto failed_mount_group_desc;
1000                }
1001        }
1002        if (!ext2_check_descriptors (sb)) {
1003                printk ("EXT2-fs: group descriptors corrupted!\n");
1004                goto failed_mount2;
1005        }
1006        sbi->s_gdb_count = db_count;
1007        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1008        spin_lock_init(&sbi->s_next_gen_lock);
1009
1010        /* per fileystem reservation list head & lock */
1011        spin_lock_init(&sbi->s_rsv_window_lock);
1012        sbi->s_rsv_window_root = RB_ROOT;
1013        /*
1014         * Add a single, static dummy reservation to the start of the
1015         * reservation window list --- it gives us a placeholder for
1016         * append-at-start-of-list which makes the allocation logic
1017         * _much_ simpler.
1018         */
1019        sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1020        sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1021        sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1022        sbi->s_rsv_window_head.rsv_goal_size = 0;
1023        ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1024
1025        err = percpu_counter_init(&sbi->s_freeblocks_counter,
1026                                ext2_count_free_blocks(sb));
1027        if (!err) {
1028                err = percpu_counter_init(&sbi->s_freeinodes_counter,
1029                                ext2_count_free_inodes(sb));
1030        }
1031        if (!err) {
1032                err = percpu_counter_init(&sbi->s_dirs_counter,
1033                                ext2_count_dirs(sb));
1034        }
1035        if (err) {
1036                printk(KERN_ERR "EXT2-fs: insufficient memory\n");
1037                goto failed_mount3;
1038        }
1039        /*
1040         * set up enough so that it can read an inode
1041         */
1042        sb->s_op = &ext2_sops;
1043        sb->s_export_op = &ext2_export_ops;
1044        sb->s_xattr = ext2_xattr_handlers;
1045        root = ext2_iget(sb, EXT2_ROOT_INO);
1046        if (IS_ERR(root)) {
1047                ret = PTR_ERR(root);
1048                goto failed_mount3;
1049        }
1050        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1051                iput(root);
1052                printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
1053                goto failed_mount3;
1054        }
1055
1056        sb->s_root = d_alloc_root(root);
1057        if (!sb->s_root) {
1058                iput(root);
1059                printk(KERN_ERR "EXT2-fs: get root inode failed\n");
1060                ret = -ENOMEM;
1061                goto failed_mount3;
1062        }
1063        if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1064                ext2_warning(sb, __func__,
1065                        "mounting ext3 filesystem as ext2");
1066        ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY);
1067        return 0;
1068
1069cantfind_ext2:
1070        if (!silent)
1071                printk("VFS: Can't find an ext2 filesystem on dev %s.\n",
1072                       sb->s_id);
1073        goto failed_mount;
1074failed_mount3:
1075        percpu_counter_destroy(&sbi->s_freeblocks_counter);
1076        percpu_counter_destroy(&sbi->s_freeinodes_counter);
1077        percpu_counter_destroy(&sbi->s_dirs_counter);
1078failed_mount2:
1079        for (i = 0; i < db_count; i++)
1080                brelse(sbi->s_group_desc[i]);
1081failed_mount_group_desc:
1082        kfree(sbi->s_group_desc);
1083        kfree(sbi->s_debts);
1084failed_mount:
1085        brelse(bh);
1086failed_sbi:
1087        sb->s_fs_info = NULL;
1088        kfree(sbi);
1089        return ret;
1090}
1091
1092static void ext2_commit_super (struct super_block * sb,
1093                               struct ext2_super_block * es)
1094{
1095        es->s_wtime = cpu_to_le32(get_seconds());
1096        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1097        sb->s_dirt = 0;
1098}
1099
1100static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es)
1101{
1102        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1103        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1104        es->s_wtime = cpu_to_le32(get_seconds());
1105        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1106        sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1107        sb->s_dirt = 0;
1108}
1109
1110/*
1111 * In the second extended file system, it is not necessary to
1112 * write the super block since we use a mapping of the
1113 * disk super block in a buffer.
1114 *
1115 * However, this function is still used to set the fs valid
1116 * flags to 0.  We need to set this flag to 0 since the fs
1117 * may have been checked while mounted and e2fsck may have
1118 * set s_state to EXT2_VALID_FS after some corrections.
1119 */
1120
1121void ext2_write_super (struct super_block * sb)
1122{
1123        struct ext2_super_block * es;
1124        lock_kernel();
1125        if (!(sb->s_flags & MS_RDONLY)) {
1126                es = EXT2_SB(sb)->s_es;
1127
1128                if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1129                        ext2_debug ("setting valid to 0\n");
1130                        es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1131                        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1132                        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1133                        es->s_mtime = cpu_to_le32(get_seconds());
1134                        ext2_sync_super(sb, es);
1135                } else
1136                        ext2_commit_super (sb, es);
1137        }
1138        sb->s_dirt = 0;
1139        unlock_kernel();
1140}
1141
1142static int ext2_remount (struct super_block * sb, int * flags, char * data)
1143{
1144        struct ext2_sb_info * sbi = EXT2_SB(sb);
1145        struct ext2_super_block * es;
1146        unsigned long old_mount_opt = sbi->s_mount_opt;
1147        struct ext2_mount_options old_opts;
1148        unsigned long old_sb_flags;
1149        int err;
1150
1151        /* Store the old options */
1152        old_sb_flags = sb->s_flags;
1153        old_opts.s_mount_opt = sbi->s_mount_opt;
1154        old_opts.s_resuid = sbi->s_resuid;
1155        old_opts.s_resgid = sbi->s_resgid;
1156
1157        /*
1158         * Allow the "check" option to be passed as a remount option.
1159         */
1160        if (!parse_options (data, sbi)) {
1161                err = -EINVAL;
1162                goto restore_opts;
1163        }
1164
1165        sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
1166                ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
1167
1168        ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
1169                                    EXT2_MOUNT_XIP if not */
1170
1171        if ((ext2_use_xip(sb)) && (sb->s_blocksize != PAGE_SIZE)) {
1172                printk("XIP: Unsupported blocksize\n");
1173                err = -EINVAL;
1174                goto restore_opts;
1175        }
1176
1177        es = sbi->s_es;
1178        if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=
1179            (old_mount_opt & EXT2_MOUNT_XIP)) &&
1180            invalidate_inodes(sb))
1181                ext2_warning(sb, __func__, "busy inodes while remounting "\
1182                             "xip remain in cache (no functional problem)");
1183        if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1184                return 0;
1185        if (*flags & MS_RDONLY) {
1186                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1187                    !(sbi->s_mount_state & EXT2_VALID_FS))
1188                        return 0;
1189                /*
1190                 * OK, we are remounting a valid rw partition rdonly, so set
1191                 * the rdonly flag and then mark the partition as valid again.
1192                 */
1193                es->s_state = cpu_to_le16(sbi->s_mount_state);
1194                es->s_mtime = cpu_to_le32(get_seconds());
1195        } else {
1196                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1197                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
1198                if (ret) {
1199                        printk("EXT2-fs: %s: couldn't remount RDWR because of "
1200                               "unsupported optional features (%x).\n",
1201                               sb->s_id, le32_to_cpu(ret));
1202                        err = -EROFS;
1203                        goto restore_opts;
1204                }
1205                /*
1206                 * Mounting a RDONLY partition read-write, so reread and
1207                 * store the current valid flag.  (It may have been changed
1208                 * by e2fsck since we originally mounted the partition.)
1209                 */
1210                sbi->s_mount_state = le16_to_cpu(es->s_state);
1211                if (!ext2_setup_super (sb, es, 0))
1212                        sb->s_flags &= ~MS_RDONLY;
1213        }
1214        ext2_sync_super(sb, es);
1215        return 0;
1216restore_opts:
1217        sbi->s_mount_opt = old_opts.s_mount_opt;
1218        sbi->s_resuid = old_opts.s_resuid;
1219        sbi->s_resgid = old_opts.s_resgid;
1220        sb->s_flags = old_sb_flags;
1221        return err;
1222}
1223
1224static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1225{
1226        struct super_block *sb = dentry->d_sb;
1227        struct ext2_sb_info *sbi = EXT2_SB(sb);
1228        struct ext2_super_block *es = sbi->s_es;
1229        u64 fsid;
1230
1231        if (test_opt (sb, MINIX_DF))
1232                sbi->s_overhead_last = 0;
1233        else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1234                unsigned long i, overhead = 0;
1235                smp_rmb();
1236
1237                /*
1238                 * Compute the overhead (FS structures). This is constant
1239                 * for a given filesystem unless the number of block groups
1240                 * changes so we cache the previous value until it does.
1241                 */
1242
1243                /*
1244                 * All of the blocks before first_data_block are
1245                 * overhead
1246                 */
1247                overhead = le32_to_cpu(es->s_first_data_block);
1248
1249                /*
1250                 * Add the overhead attributed to the superblock and
1251                 * block group descriptors.  If the sparse superblocks
1252                 * feature is turned on, then not all groups have this.
1253                 */
1254                for (i = 0; i < sbi->s_groups_count; i++)
1255                        overhead += ext2_bg_has_super(sb, i) +
1256                                ext2_bg_num_gdb(sb, i);
1257
1258                /*
1259                 * Every block group has an inode bitmap, a block
1260                 * bitmap, and an inode table.
1261                 */
1262                overhead += (sbi->s_groups_count *
1263                             (2 + sbi->s_itb_per_group));
1264                sbi->s_overhead_last = overhead;
1265                smp_wmb();
1266                sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1267        }
1268
1269        buf->f_type = EXT2_SUPER_MAGIC;
1270        buf->f_bsize = sb->s_blocksize;
1271        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1272        buf->f_bfree = ext2_count_free_blocks(sb);
1273        es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1274        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1275        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1276                buf->f_bavail = 0;
1277        buf->f_files = le32_to_cpu(es->s_inodes_count);
1278        buf->f_ffree = ext2_count_free_inodes(sb);
1279        es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1280        buf->f_namelen = EXT2_NAME_LEN;
1281        fsid = le64_to_cpup((void *)es->s_uuid) ^
1282               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1283        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1284        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1285        return 0;
1286}
1287
1288static int ext2_get_sb(struct file_system_type *fs_type,
1289        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
1290{
1291        return get_sb_bdev(fs_type, flags, dev_name, data, ext2_fill_super, mnt);
1292}
1293
1294#ifdef CONFIG_QUOTA
1295
1296/* Read data from quotafile - avoid pagecache and such because we cannot afford
1297 * acquiring the locks... As quota files are never truncated and quota code
1298 * itself serializes the operations (and noone else should touch the files)
1299 * we don't have to be afraid of races */
1300static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1301                               size_t len, loff_t off)
1302{
1303        struct inode *inode = sb_dqopt(sb)->files[type];
1304        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1305        int err = 0;
1306        int offset = off & (sb->s_blocksize - 1);
1307        int tocopy;
1308        size_t toread;
1309        struct buffer_head tmp_bh;
1310        struct buffer_head *bh;
1311        loff_t i_size = i_size_read(inode);
1312
1313        if (off > i_size)
1314                return 0;
1315        if (off+len > i_size)
1316                len = i_size-off;
1317        toread = len;
1318        while (toread > 0) {
1319                tocopy = sb->s_blocksize - offset < toread ?
1320                                sb->s_blocksize - offset : toread;
1321
1322                tmp_bh.b_state = 0;
1323                err = ext2_get_block(inode, blk, &tmp_bh, 0);
1324                if (err < 0)
1325                        return err;
1326                if (!buffer_mapped(&tmp_bh))        /* A hole? */
1327                        memset(data, 0, tocopy);
1328                else {
1329                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1330                        if (!bh)
1331                                return -EIO;
1332                        memcpy(data, bh->b_data+offset, tocopy);
1333                        brelse(bh);
1334                }
1335                offset = 0;
1336                toread -= tocopy;
1337                data += tocopy;
1338                blk++;
1339        }
1340        return len;
1341}
1342
1343/* Write to quotafile */
1344static ssize_t ext2_quota_write(struct super_block *sb, int type,
1345                                const char *data, size_t len, loff_t off)
1346{
1347        struct inode *inode = sb_dqopt(sb)->files[type];
1348        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1349        int err = 0;
1350        int offset = off & (sb->s_blocksize - 1);
1351        int tocopy;
1352        size_t towrite = len;
1353        struct buffer_head tmp_bh;
1354        struct buffer_head *bh;
1355
1356        mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
1357        while (towrite > 0) {
1358                tocopy = sb->s_blocksize - offset < towrite ?
1359                                sb->s_blocksize - offset : towrite;
1360
1361                tmp_bh.b_state = 0;
1362                err = ext2_get_block(inode, blk, &tmp_bh, 1);
1363                if (err < 0)
1364                        goto out;
1365                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1366                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1367                else
1368                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
1369                if (!bh) {
1370                        err = -EIO;
1371                        goto out;
1372                }
1373                lock_buffer(bh);
1374                memcpy(bh->b_data+offset, data, tocopy);
1375                flush_dcache_page(bh->b_page);
1376                set_buffer_uptodate(bh);
1377                mark_buffer_dirty(bh);
1378                unlock_buffer(bh);
1379                brelse(bh);
1380                offset = 0;
1381                towrite -= tocopy;
1382                data += tocopy;
1383                blk++;
1384        }
1385out:
1386        if (len == towrite)
1387                return err;
1388        if (inode->i_size < off+len-towrite)
1389                i_size_write(inode, off+len-towrite);
1390        inode->i_version++;
1391        inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1392        mark_inode_dirty(inode);
1393        mutex_unlock(&inode->i_mutex);
1394        return len - towrite;
1395}
1396
1397#endif
1398
1399static struct file_system_type ext2_fs_type = {
1400        .owner                = THIS_MODULE,
1401        .name                = "ext2",
1402        .get_sb                = ext2_get_sb,
1403        .kill_sb        = kill_block_super,
1404        .fs_flags        = FS_REQUIRES_DEV,
1405};
1406
1407static int __init init_ext2_fs(void)
1408{
1409        int err = init_ext2_xattr();
1410        if (err)
1411                return err;
1412        err = init_inodecache();
1413        if (err)
1414                goto out1;
1415        err = register_filesystem(&ext2_fs_type);
1416        if (err)
1417                goto out;
1418        return 0;
1419out:
1420        destroy_inodecache();
1421out1:
1422        exit_ext2_xattr();
1423        return err;
1424}
1425
1426static void __exit exit_ext2_fs(void)
1427{
1428        unregister_filesystem(&ext2_fs_type);
1429        destroy_inodecache();
1430        exit_ext2_xattr();
1431}
1432
1433module_init(init_ext2_fs)
1434module_exit(exit_ext2_fs)