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 <linux/uaccess.h>
  35#include <linux/dax.h>
  36#include <linux/iversion.h>
  37#include "ext2.h"
  38#include "xattr.h"
  39#include "acl.h"
  40
  41static void ext2_write_super(struct super_block *sb);
  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_rdonly(sb)) {
  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 |= SB_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
 127#ifdef CONFIG_QUOTA
 128static int ext2_quota_off(struct super_block *sb, int type);
 129
 130static void ext2_quota_off_umount(struct super_block *sb)
 131{
 132        int type;
 133
 134        for (type = 0; type < MAXQUOTAS; type++)
 135                ext2_quota_off(sb, type);
 136}
 137#else
 138static inline void ext2_quota_off_umount(struct super_block *sb)
 139{
 140}
 141#endif
 142
 143static void ext2_put_super (struct super_block * sb)
 144{
 145        int db_count;
 146        int i;
 147        struct ext2_sb_info *sbi = EXT2_SB(sb);
 148
 149        ext2_quota_off_umount(sb);
 150
 151        if (sbi->s_ea_block_cache) {
 152                ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
 153                sbi->s_ea_block_cache = NULL;
 154        }
 155        if (!sb_rdonly(sb)) {
 156                struct ext2_super_block *es = sbi->s_es;
 157
 158                spin_lock(&sbi->s_lock);
 159                es->s_state = cpu_to_le16(sbi->s_mount_state);
 160                spin_unlock(&sbi->s_lock);
 161                ext2_sync_super(sb, es, 1);
 162        }
 163        db_count = sbi->s_gdb_count;
 164        for (i = 0; i < db_count; i++)
 165                if (sbi->s_group_desc[i])
 166                        brelse (sbi->s_group_desc[i]);
 167        kfree(sbi->s_group_desc);
 168        kfree(sbi->s_debts);
 169        percpu_counter_destroy(&sbi->s_freeblocks_counter);
 170        percpu_counter_destroy(&sbi->s_freeinodes_counter);
 171        percpu_counter_destroy(&sbi->s_dirs_counter);
 172        brelse (sbi->s_sbh);
 173        sb->s_fs_info = NULL;
 174        kfree(sbi->s_blockgroup_lock);
 175        fs_put_dax(sbi->s_daxdev);
 176        kfree(sbi);
 177}
 178
 179static struct kmem_cache * ext2_inode_cachep;
 180
 181static struct inode *ext2_alloc_inode(struct super_block *sb)
 182{
 183        struct ext2_inode_info *ei;
 184        ei = kmem_cache_alloc(ext2_inode_cachep, GFP_KERNEL);
 185        if (!ei)
 186                return NULL;
 187        ei->i_block_alloc_info = NULL;
 188        inode_set_iversion(&ei->vfs_inode, 1);
 189#ifdef CONFIG_QUOTA
 190        memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 191#endif
 192
 193        return &ei->vfs_inode;
 194}
 195
 196static void ext2_i_callback(struct rcu_head *head)
 197{
 198        struct inode *inode = container_of(head, struct inode, i_rcu);
 199        kmem_cache_free(ext2_inode_cachep, EXT2_I(inode));
 200}
 201
 202static void ext2_destroy_inode(struct inode *inode)
 203{
 204        call_rcu(&inode->i_rcu, ext2_i_callback);
 205}
 206
 207static void init_once(void *foo)
 208{
 209        struct ext2_inode_info *ei = (struct ext2_inode_info *) foo;
 210
 211        rwlock_init(&ei->i_meta_lock);
 212#ifdef CONFIG_EXT2_FS_XATTR
 213        init_rwsem(&ei->xattr_sem);
 214#endif
 215        mutex_init(&ei->truncate_mutex);
 216#ifdef CONFIG_FS_DAX
 217        init_rwsem(&ei->dax_sem);
 218#endif
 219        inode_init_once(&ei->vfs_inode);
 220}
 221
 222static int __init init_inodecache(void)
 223{
 224        ext2_inode_cachep = kmem_cache_create_usercopy("ext2_inode_cache",
 225                                sizeof(struct ext2_inode_info), 0,
 226                                (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
 227                                        SLAB_ACCOUNT),
 228                                offsetof(struct ext2_inode_info, i_data),
 229                                sizeof_field(struct ext2_inode_info, i_data),
 230                                init_once);
 231        if (ext2_inode_cachep == NULL)
 232                return -ENOMEM;
 233        return 0;
 234}
 235
 236static void destroy_inodecache(void)
 237{
 238        /*
 239         * Make sure all delayed rcu free inodes are flushed before we
 240         * destroy cache.
 241         */
 242        rcu_barrier();
 243        kmem_cache_destroy(ext2_inode_cachep);
 244}
 245
 246static int ext2_show_options(struct seq_file *seq, struct dentry *root)
 247{
 248        struct super_block *sb = root->d_sb;
 249        struct ext2_sb_info *sbi = EXT2_SB(sb);
 250        struct ext2_super_block *es = sbi->s_es;
 251        unsigned long def_mount_opts;
 252
 253        spin_lock(&sbi->s_lock);
 254        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 255
 256        if (sbi->s_sb_block != 1)
 257                seq_printf(seq, ",sb=%lu", sbi->s_sb_block);
 258        if (test_opt(sb, MINIX_DF))
 259                seq_puts(seq, ",minixdf");
 260        if (test_opt(sb, GRPID))
 261                seq_puts(seq, ",grpid");
 262        if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))
 263                seq_puts(seq, ",nogrpid");
 264        if (!uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT2_DEF_RESUID)) ||
 265            le16_to_cpu(es->s_def_resuid) != EXT2_DEF_RESUID) {
 266                seq_printf(seq, ",resuid=%u",
 267                                from_kuid_munged(&init_user_ns, sbi->s_resuid));
 268        }
 269        if (!gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT2_DEF_RESGID)) ||
 270            le16_to_cpu(es->s_def_resgid) != EXT2_DEF_RESGID) {
 271                seq_printf(seq, ",resgid=%u",
 272                                from_kgid_munged(&init_user_ns, sbi->s_resgid));
 273        }
 274        if (test_opt(sb, ERRORS_RO)) {
 275                int def_errors = le16_to_cpu(es->s_errors);
 276
 277                if (def_errors == EXT2_ERRORS_PANIC ||
 278                    def_errors == EXT2_ERRORS_CONTINUE) {
 279                        seq_puts(seq, ",errors=remount-ro");
 280                }
 281        }
 282        if (test_opt(sb, ERRORS_CONT))
 283                seq_puts(seq, ",errors=continue");
 284        if (test_opt(sb, ERRORS_PANIC))
 285                seq_puts(seq, ",errors=panic");
 286        if (test_opt(sb, NO_UID32))
 287                seq_puts(seq, ",nouid32");
 288        if (test_opt(sb, DEBUG))
 289                seq_puts(seq, ",debug");
 290        if (test_opt(sb, OLDALLOC))
 291                seq_puts(seq, ",oldalloc");
 292
 293#ifdef CONFIG_EXT2_FS_XATTR
 294        if (test_opt(sb, XATTR_USER))
 295                seq_puts(seq, ",user_xattr");
 296        if (!test_opt(sb, XATTR_USER) &&
 297            (def_mount_opts & EXT2_DEFM_XATTR_USER)) {
 298                seq_puts(seq, ",nouser_xattr");
 299        }
 300#endif
 301
 302#ifdef CONFIG_EXT2_FS_POSIX_ACL
 303        if (test_opt(sb, POSIX_ACL))
 304                seq_puts(seq, ",acl");
 305        if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))
 306                seq_puts(seq, ",noacl");
 307#endif
 308
 309        if (test_opt(sb, NOBH))
 310                seq_puts(seq, ",nobh");
 311
 312#if defined(CONFIG_QUOTA)
 313        if (sbi->s_mount_opt & EXT2_MOUNT_USRQUOTA)
 314                seq_puts(seq, ",usrquota");
 315
 316        if (sbi->s_mount_opt & EXT2_MOUNT_GRPQUOTA)
 317                seq_puts(seq, ",grpquota");
 318#endif
 319
 320#ifdef CONFIG_FS_DAX
 321        if (sbi->s_mount_opt & EXT2_MOUNT_XIP)
 322                seq_puts(seq, ",xip");
 323        if (sbi->s_mount_opt & EXT2_MOUNT_DAX)
 324                seq_puts(seq, ",dax");
 325#endif
 326
 327        if (!test_opt(sb, RESERVATION))
 328                seq_puts(seq, ",noreservation");
 329
 330        spin_unlock(&sbi->s_lock);
 331        return 0;
 332}
 333
 334#ifdef CONFIG_QUOTA
 335static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off);
 336static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, loff_t off);
 337static int ext2_quota_on(struct super_block *sb, int type, int format_id,
 338                         const struct path *path);
 339static struct dquot **ext2_get_dquots(struct inode *inode)
 340{
 341        return EXT2_I(inode)->i_dquot;
 342}
 343
 344static const struct quotactl_ops ext2_quotactl_ops = {
 345        .quota_on       = ext2_quota_on,
 346        .quota_off      = ext2_quota_off,
 347        .quota_sync     = dquot_quota_sync,
 348        .get_state      = dquot_get_state,
 349        .set_info       = dquot_set_dqinfo,
 350        .get_dqblk      = dquot_get_dqblk,
 351        .set_dqblk      = dquot_set_dqblk,
 352        .get_nextdqblk  = dquot_get_next_dqblk,
 353};
 354#endif
 355
 356static const struct super_operations ext2_sops = {
 357        .alloc_inode    = ext2_alloc_inode,
 358        .destroy_inode  = ext2_destroy_inode,
 359        .write_inode    = ext2_write_inode,
 360        .evict_inode    = ext2_evict_inode,
 361        .put_super      = ext2_put_super,
 362        .sync_fs        = ext2_sync_fs,
 363        .freeze_fs      = ext2_freeze,
 364        .unfreeze_fs    = ext2_unfreeze,
 365        .statfs         = ext2_statfs,
 366        .remount_fs     = ext2_remount,
 367        .show_options   = ext2_show_options,
 368#ifdef CONFIG_QUOTA
 369        .quota_read     = ext2_quota_read,
 370        .quota_write    = ext2_quota_write,
 371        .get_dquots     = ext2_get_dquots,
 372#endif
 373};
 374
 375static struct inode *ext2_nfs_get_inode(struct super_block *sb,
 376                u64 ino, u32 generation)
 377{
 378        struct inode *inode;
 379
 380        if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
 381                return ERR_PTR(-ESTALE);
 382        if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
 383                return ERR_PTR(-ESTALE);
 384
 385        /*
 386         * ext2_iget isn't quite right if the inode is currently unallocated!
 387         * However ext2_iget currently does appropriate checks to handle stale
 388         * inodes so everything is OK.
 389         */
 390        inode = ext2_iget(sb, ino);
 391        if (IS_ERR(inode))
 392                return ERR_CAST(inode);
 393        if (generation && inode->i_generation != generation) {
 394                /* we didn't find the right inode.. */
 395                iput(inode);
 396                return ERR_PTR(-ESTALE);
 397        }
 398        return inode;
 399}
 400
 401static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 402                int fh_len, int fh_type)
 403{
 404        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 405                                    ext2_nfs_get_inode);
 406}
 407
 408static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,
 409                int fh_len, int fh_type)
 410{
 411        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 412                                    ext2_nfs_get_inode);
 413}
 414
 415static const struct export_operations ext2_export_ops = {
 416        .fh_to_dentry = ext2_fh_to_dentry,
 417        .fh_to_parent = ext2_fh_to_parent,
 418        .get_parent = ext2_get_parent,
 419};
 420
 421static unsigned long get_sb_block(void **data)
 422{
 423        unsigned long   sb_block;
 424        char            *options = (char *) *data;
 425
 426        if (!options || strncmp(options, "sb=", 3) != 0)
 427                return 1;       /* Default location */
 428        options += 3;
 429        sb_block = simple_strtoul(options, &options, 0);
 430        if (*options && *options != ',') {
 431                printk("EXT2-fs: Invalid sb specification: %s\n",
 432                       (char *) *data);
 433                return 1;
 434        }
 435        if (*options == ',')
 436                options++;
 437        *data = (void *) options;
 438        return sb_block;
 439}
 440
 441enum {
 442        Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
 443        Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic,
 444        Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug,
 445        Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr,
 446        Opt_acl, Opt_noacl, Opt_xip, Opt_dax, Opt_ignore, Opt_err, Opt_quota,
 447        Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation
 448};
 449
 450static const match_table_t tokens = {
 451        {Opt_bsd_df, "bsddf"},
 452        {Opt_minix_df, "minixdf"},
 453        {Opt_grpid, "grpid"},
 454        {Opt_grpid, "bsdgroups"},
 455        {Opt_nogrpid, "nogrpid"},
 456        {Opt_nogrpid, "sysvgroups"},
 457        {Opt_resgid, "resgid=%u"},
 458        {Opt_resuid, "resuid=%u"},
 459        {Opt_sb, "sb=%u"},
 460        {Opt_err_cont, "errors=continue"},
 461        {Opt_err_panic, "errors=panic"},
 462        {Opt_err_ro, "errors=remount-ro"},
 463        {Opt_nouid32, "nouid32"},
 464        {Opt_nocheck, "check=none"},
 465        {Opt_nocheck, "nocheck"},
 466        {Opt_debug, "debug"},
 467        {Opt_oldalloc, "oldalloc"},
 468        {Opt_orlov, "orlov"},
 469        {Opt_nobh, "nobh"},
 470        {Opt_user_xattr, "user_xattr"},
 471        {Opt_nouser_xattr, "nouser_xattr"},
 472        {Opt_acl, "acl"},
 473        {Opt_noacl, "noacl"},
 474        {Opt_xip, "xip"},
 475        {Opt_dax, "dax"},
 476        {Opt_grpquota, "grpquota"},
 477        {Opt_ignore, "noquota"},
 478        {Opt_quota, "quota"},
 479        {Opt_usrquota, "usrquota"},
 480        {Opt_reservation, "reservation"},
 481        {Opt_noreservation, "noreservation"},
 482        {Opt_err, NULL}
 483};
 484
 485static int parse_options(char *options, struct super_block *sb,
 486                         struct ext2_mount_options *opts)
 487{
 488        char *p;
 489        substring_t args[MAX_OPT_ARGS];
 490        int option;
 491        kuid_t uid;
 492        kgid_t gid;
 493
 494        if (!options)
 495                return 1;
 496
 497        while ((p = strsep (&options, ",")) != NULL) {
 498                int token;
 499                if (!*p)
 500                        continue;
 501
 502                token = match_token(p, tokens, args);
 503                switch (token) {
 504                case Opt_bsd_df:
 505                        clear_opt (opts->s_mount_opt, MINIX_DF);
 506                        break;
 507                case Opt_minix_df:
 508                        set_opt (opts->s_mount_opt, MINIX_DF);
 509                        break;
 510                case Opt_grpid:
 511                        set_opt (opts->s_mount_opt, GRPID);
 512                        break;
 513                case Opt_nogrpid:
 514                        clear_opt (opts->s_mount_opt, GRPID);
 515                        break;
 516                case Opt_resuid:
 517                        if (match_int(&args[0], &option))
 518                                return 0;
 519                        uid = make_kuid(current_user_ns(), option);
 520                        if (!uid_valid(uid)) {
 521                                ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);
 522                                return 0;
 523
 524                        }
 525                        opts->s_resuid = uid;
 526                        break;
 527                case Opt_resgid:
 528                        if (match_int(&args[0], &option))
 529                                return 0;
 530                        gid = make_kgid(current_user_ns(), option);
 531                        if (!gid_valid(gid)) {
 532                                ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);
 533                                return 0;
 534                        }
 535                        opts->s_resgid = gid;
 536                        break;
 537                case Opt_sb:
 538                        /* handled by get_sb_block() instead of here */
 539                        /* *sb_block = match_int(&args[0]); */
 540                        break;
 541                case Opt_err_panic:
 542                        clear_opt (opts->s_mount_opt, ERRORS_CONT);
 543                        clear_opt (opts->s_mount_opt, ERRORS_RO);
 544                        set_opt (opts->s_mount_opt, ERRORS_PANIC);
 545                        break;
 546                case Opt_err_ro:
 547                        clear_opt (opts->s_mount_opt, ERRORS_CONT);
 548                        clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 549                        set_opt (opts->s_mount_opt, ERRORS_RO);
 550                        break;
 551                case Opt_err_cont:
 552                        clear_opt (opts->s_mount_opt, ERRORS_RO);
 553                        clear_opt (opts->s_mount_opt, ERRORS_PANIC);
 554                        set_opt (opts->s_mount_opt, ERRORS_CONT);
 555                        break;
 556                case Opt_nouid32:
 557                        set_opt (opts->s_mount_opt, NO_UID32);
 558                        break;
 559                case Opt_nocheck:
 560                        clear_opt (opts->s_mount_opt, CHECK);
 561                        break;
 562                case Opt_debug:
 563                        set_opt (opts->s_mount_opt, DEBUG);
 564                        break;
 565                case Opt_oldalloc:
 566                        set_opt (opts->s_mount_opt, OLDALLOC);
 567                        break;
 568                case Opt_orlov:
 569                        clear_opt (opts->s_mount_opt, OLDALLOC);
 570                        break;
 571                case Opt_nobh:
 572                        set_opt (opts->s_mount_opt, NOBH);
 573                        break;
 574#ifdef CONFIG_EXT2_FS_XATTR
 575                case Opt_user_xattr:
 576                        set_opt (opts->s_mount_opt, XATTR_USER);
 577                        break;
 578                case Opt_nouser_xattr:
 579                        clear_opt (opts->s_mount_opt, XATTR_USER);
 580                        break;
 581#else
 582                case Opt_user_xattr:
 583                case Opt_nouser_xattr:
 584                        ext2_msg(sb, KERN_INFO, "(no)user_xattr options"
 585                                "not supported");
 586                        break;
 587#endif
 588#ifdef CONFIG_EXT2_FS_POSIX_ACL
 589                case Opt_acl:
 590                        set_opt(opts->s_mount_opt, POSIX_ACL);
 591                        break;
 592                case Opt_noacl:
 593                        clear_opt(opts->s_mount_opt, POSIX_ACL);
 594                        break;
 595#else
 596                case Opt_acl:
 597                case Opt_noacl:
 598                        ext2_msg(sb, KERN_INFO,
 599                                "(no)acl options not supported");
 600                        break;
 601#endif
 602                case Opt_xip:
 603                        ext2_msg(sb, KERN_INFO, "use dax instead of xip");
 604                        set_opt(opts->s_mount_opt, XIP);
 605                        /* Fall through */
 606                case Opt_dax:
 607#ifdef CONFIG_FS_DAX
 608                        ext2_msg(sb, KERN_WARNING,
 609                "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 610                        set_opt(opts->s_mount_opt, DAX);
 611#else
 612                        ext2_msg(sb, KERN_INFO, "dax option not supported");
 613#endif
 614                        break;
 615
 616#if defined(CONFIG_QUOTA)
 617                case Opt_quota:
 618                case Opt_usrquota:
 619                        set_opt(opts->s_mount_opt, USRQUOTA);
 620                        break;
 621
 622                case Opt_grpquota:
 623                        set_opt(opts->s_mount_opt, GRPQUOTA);
 624                        break;
 625#else
 626                case Opt_quota:
 627                case Opt_usrquota:
 628                case Opt_grpquota:
 629                        ext2_msg(sb, KERN_INFO,
 630                                "quota operations not supported");
 631                        break;
 632#endif
 633
 634                case Opt_reservation:
 635                        set_opt(opts->s_mount_opt, RESERVATION);
 636                        ext2_msg(sb, KERN_INFO, "reservations ON");
 637                        break;
 638                case Opt_noreservation:
 639                        clear_opt(opts->s_mount_opt, RESERVATION);
 640                        ext2_msg(sb, KERN_INFO, "reservations OFF");
 641                        break;
 642                case Opt_ignore:
 643                        break;
 644                default:
 645                        return 0;
 646                }
 647        }
 648        return 1;
 649}
 650
 651static int ext2_setup_super (struct super_block * sb,
 652                              struct ext2_super_block * es,
 653                              int read_only)
 654{
 655        int res = 0;
 656        struct ext2_sb_info *sbi = EXT2_SB(sb);
 657
 658        if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
 659                ext2_msg(sb, KERN_ERR,
 660                        "error: revision level too high, "
 661                        "forcing read-only mode");
 662                res = SB_RDONLY;
 663        }
 664        if (read_only)
 665                return res;
 666        if (!(sbi->s_mount_state & EXT2_VALID_FS))
 667                ext2_msg(sb, KERN_WARNING,
 668                        "warning: mounting unchecked fs, "
 669                        "running e2fsck is recommended");
 670        else if ((sbi->s_mount_state & EXT2_ERROR_FS))
 671                ext2_msg(sb, KERN_WARNING,
 672                        "warning: mounting fs with errors, "
 673                        "running e2fsck is recommended");
 674        else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
 675                 le16_to_cpu(es->s_mnt_count) >=
 676                 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 677                ext2_msg(sb, KERN_WARNING,
 678                        "warning: maximal mount count reached, "
 679                        "running e2fsck is recommended");
 680        else if (le32_to_cpu(es->s_checkinterval) &&
 681                (le32_to_cpu(es->s_lastcheck) +
 682                        le32_to_cpu(es->s_checkinterval) <= get_seconds()))
 683                ext2_msg(sb, KERN_WARNING,
 684                        "warning: checktime reached, "
 685                        "running e2fsck is recommended");
 686        if (!le16_to_cpu(es->s_max_mnt_count))
 687                es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
 688        le16_add_cpu(&es->s_mnt_count, 1);
 689        if (test_opt (sb, DEBUG))
 690                ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, fs=%lu, gc=%lu, "
 691                        "bpg=%lu, ipg=%lu, mo=%04lx]",
 692                        EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
 693                        sbi->s_frag_size,
 694                        sbi->s_groups_count,
 695                        EXT2_BLOCKS_PER_GROUP(sb),
 696                        EXT2_INODES_PER_GROUP(sb),
 697                        sbi->s_mount_opt);
 698        return res;
 699}
 700
 701static int ext2_check_descriptors(struct super_block *sb)
 702{
 703        int i;
 704        struct ext2_sb_info *sbi = EXT2_SB(sb);
 705
 706        ext2_debug ("Checking group descriptors");
 707
 708        for (i = 0; i < sbi->s_groups_count; i++) {
 709                struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);
 710                ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);
 711                ext2_fsblk_t last_block;
 712
 713                if (i == sbi->s_groups_count - 1)
 714                        last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
 715                else
 716                        last_block = first_block +
 717                                (EXT2_BLOCKS_PER_GROUP(sb) - 1);
 718
 719                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
 720                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 721                {
 722                        ext2_error (sb, "ext2_check_descriptors",
 723                                    "Block bitmap for group %d"
 724                                    " not in group (block %lu)!",
 725                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
 726                        return 0;
 727                }
 728                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
 729                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 730                {
 731                        ext2_error (sb, "ext2_check_descriptors",
 732                                    "Inode bitmap for group %d"
 733                                    " not in group (block %lu)!",
 734                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
 735                        return 0;
 736                }
 737                if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
 738                    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
 739                    last_block)
 740                {
 741                        ext2_error (sb, "ext2_check_descriptors",
 742                                    "Inode table for group %d"
 743                                    " not in group (block %lu)!",
 744                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
 745                        return 0;
 746                }
 747        }
 748        return 1;
 749}
 750
 751/*
 752 * Maximal file size.  There is a direct, and {,double-,triple-}indirect
 753 * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
 754 * We need to be 1 filesystem block less than the 2^32 sector limit.
 755 */
 756static loff_t ext2_max_size(int bits)
 757{
 758        loff_t res = EXT2_NDIR_BLOCKS;
 759        int meta_blocks;
 760        loff_t upper_limit;
 761
 762        /* This is calculated to be the largest file size for a
 763         * dense, file such that the total number of
 764         * sectors in the file, including data and all indirect blocks,
 765         * does not exceed 2^32 -1
 766         * __u32 i_blocks representing the total number of
 767         * 512 bytes blocks of the file
 768         */
 769        upper_limit = (1LL << 32) - 1;
 770
 771        /* total blocks in file system block size */
 772        upper_limit >>= (bits - 9);
 773
 774
 775        /* indirect blocks */
 776        meta_blocks = 1;
 777        /* double indirect blocks */
 778        meta_blocks += 1 + (1LL << (bits-2));
 779        /* tripple indirect blocks */
 780        meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
 781
 782        upper_limit -= meta_blocks;
 783        upper_limit <<= bits;
 784
 785        res += 1LL << (bits-2);
 786        res += 1LL << (2*(bits-2));
 787        res += 1LL << (3*(bits-2));
 788        res <<= bits;
 789        if (res > upper_limit)
 790                res = upper_limit;
 791
 792        if (res > MAX_LFS_FILESIZE)
 793                res = MAX_LFS_FILESIZE;
 794
 795        return res;
 796}
 797
 798static unsigned long descriptor_loc(struct super_block *sb,
 799                                    unsigned long logic_sb_block,
 800                                    int nr)
 801{
 802        struct ext2_sb_info *sbi = EXT2_SB(sb);
 803        unsigned long bg, first_meta_bg;
 804        int has_super = 0;
 805        
 806        first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
 807
 808        if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||
 809            nr < first_meta_bg)
 810                return (logic_sb_block + nr + 1);
 811        bg = sbi->s_desc_per_block * nr;
 812        if (ext2_bg_has_super(sb, bg))
 813                has_super = 1;
 814
 815        return ext2_group_first_block_no(sb, bg) + has_super;
 816}
 817
 818static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 819{
 820        struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
 821        struct buffer_head * bh;
 822        struct ext2_sb_info * sbi;
 823        struct ext2_super_block * es;
 824        struct inode *root;
 825        unsigned long block;
 826        unsigned long sb_block = get_sb_block(&data);
 827        unsigned long logic_sb_block;
 828        unsigned long offset = 0;
 829        unsigned long def_mount_opts;
 830        long ret = -ENOMEM;
 831        int blocksize = BLOCK_SIZE;
 832        int db_count;
 833        int i, j;
 834        __le32 features;
 835        int err;
 836        struct ext2_mount_options opts;
 837
 838        sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 839        if (!sbi)
 840                goto failed;
 841
 842        sbi->s_blockgroup_lock =
 843                kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
 844        if (!sbi->s_blockgroup_lock) {
 845                kfree(sbi);
 846                goto failed;
 847        }
 848        sb->s_fs_info = sbi;
 849        sbi->s_sb_block = sb_block;
 850        sbi->s_daxdev = dax_dev;
 851
 852        spin_lock_init(&sbi->s_lock);
 853        ret = -EINVAL;
 854
 855        /*
 856         * See what the current blocksize for the device is, and
 857         * use that as the blocksize.  Otherwise (or if the blocksize
 858         * is smaller than the default) use the default.
 859         * This is important for devices that have a hardware
 860         * sectorsize that is larger than the default.
 861         */
 862        blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
 863        if (!blocksize) {
 864                ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");
 865                goto failed_sbi;
 866        }
 867
 868        /*
 869         * If the superblock doesn't start on a hardware sector boundary,
 870         * calculate the offset.  
 871         */
 872        if (blocksize != BLOCK_SIZE) {
 873                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 874                offset = (sb_block*BLOCK_SIZE) % blocksize;
 875        } else {
 876                logic_sb_block = sb_block;
 877        }
 878
 879        if (!(bh = sb_bread(sb, logic_sb_block))) {
 880                ext2_msg(sb, KERN_ERR, "error: unable to read superblock");
 881                goto failed_sbi;
 882        }
 883        /*
 884         * Note: s_es must be initialized as soon as possible because
 885         *       some ext2 macro-instructions depend on its value
 886         */
 887        es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 888        sbi->s_es = es;
 889        sb->s_magic = le16_to_cpu(es->s_magic);
 890
 891        if (sb->s_magic != EXT2_SUPER_MAGIC)
 892                goto cantfind_ext2;
 893
 894        /* Set defaults before we parse the mount options */
 895        def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 896        if (def_mount_opts & EXT2_DEFM_DEBUG)
 897                set_opt(opts.s_mount_opt, DEBUG);
 898        if (def_mount_opts & EXT2_DEFM_BSDGROUPS)
 899                set_opt(opts.s_mount_opt, GRPID);
 900        if (def_mount_opts & EXT2_DEFM_UID16)
 901                set_opt(opts.s_mount_opt, NO_UID32);
 902#ifdef CONFIG_EXT2_FS_XATTR
 903        if (def_mount_opts & EXT2_DEFM_XATTR_USER)
 904                set_opt(opts.s_mount_opt, XATTR_USER);
 905#endif
 906#ifdef CONFIG_EXT2_FS_POSIX_ACL
 907        if (def_mount_opts & EXT2_DEFM_ACL)
 908                set_opt(opts.s_mount_opt, POSIX_ACL);
 909#endif
 910        
 911        if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_PANIC)
 912                set_opt(opts.s_mount_opt, ERRORS_PANIC);
 913        else if (le16_to_cpu(sbi->s_es->s_errors) == EXT2_ERRORS_CONTINUE)
 914                set_opt(opts.s_mount_opt, ERRORS_CONT);
 915        else
 916                set_opt(opts.s_mount_opt, ERRORS_RO);
 917
 918        opts.s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
 919        opts.s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
 920        
 921        set_opt(opts.s_mount_opt, RESERVATION);
 922
 923        if (!parse_options((char *) data, sb, &opts))
 924                goto failed_mount;
 925
 926        sbi->s_mount_opt = opts.s_mount_opt;
 927        sbi->s_resuid = opts.s_resuid;
 928        sbi->s_resgid = opts.s_resgid;
 929
 930        sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 931                ((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 932                 SB_POSIXACL : 0);
 933        sb->s_iflags |= SB_I_CGROUPWB;
 934
 935        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
 936            (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
 937             EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
 938             EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))
 939                ext2_msg(sb, KERN_WARNING,
 940                        "warning: feature flags set on rev 0 fs, "
 941                        "running e2fsck is recommended");
 942        /*
 943         * Check feature flags regardless of the revision level, since we
 944         * previously didn't change the revision level when setting the flags,
 945         * so there is a chance incompat flags are set on a rev 0 filesystem.
 946         */
 947        features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);
 948        if (features) {
 949                ext2_msg(sb, KERN_ERR,  "error: couldn't mount because of "
 950                       "unsupported optional features (%x)",
 951                        le32_to_cpu(features));
 952                goto failed_mount;
 953        }
 954        if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){
 955                ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "
 956                       "unsupported optional features (%x)",
 957                       le32_to_cpu(features));
 958                goto failed_mount;
 959        }
 960
 961        blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
 962
 963        if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
 964                err = bdev_dax_supported(sb, blocksize);
 965                if (err) {
 966                        ext2_msg(sb, KERN_ERR,
 967                                "DAX unsupported by block device. Turning off DAX.");
 968                        sbi->s_mount_opt &= ~EXT2_MOUNT_DAX;
 969                }
 970        }
 971
 972        /* If the blocksize doesn't match, re-read the thing.. */
 973        if (sb->s_blocksize != blocksize) {
 974                brelse(bh);
 975
 976                if (!sb_set_blocksize(sb, blocksize)) {
 977                        ext2_msg(sb, KERN_ERR,
 978                                "error: bad blocksize %d", blocksize);
 979                        goto failed_sbi;
 980                }
 981
 982                logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize;
 983                offset = (sb_block*BLOCK_SIZE) % blocksize;
 984                bh = sb_bread(sb, logic_sb_block);
 985                if(!bh) {
 986                        ext2_msg(sb, KERN_ERR, "error: couldn't read"
 987                                "superblock on 2nd try");
 988                        goto failed_sbi;
 989                }
 990                es = (struct ext2_super_block *) (((char *)bh->b_data) + offset);
 991                sbi->s_es = es;
 992                if (es->s_magic != cpu_to_le16(EXT2_SUPER_MAGIC)) {
 993                        ext2_msg(sb, KERN_ERR, "error: magic mismatch");
 994                        goto failed_mount;
 995                }
 996        }
 997
 998        sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 999        sb->s_max_links = EXT2_LINK_MAX;
1000
1001        if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
1002                sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
1003                sbi->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
1004        } else {
1005                sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
1006                sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
1007                if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
1008                    !is_power_of_2(sbi->s_inode_size) ||
1009                    (sbi->s_inode_size > blocksize)) {
1010                        ext2_msg(sb, KERN_ERR,
1011                                "error: unsupported inode size: %d",
1012                                sbi->s_inode_size);
1013                        goto failed_mount;
1014                }
1015        }
1016
1017        sbi->s_frag_size = EXT2_MIN_FRAG_SIZE <<
1018                                   le32_to_cpu(es->s_log_frag_size);
1019        if (sbi->s_frag_size == 0)
1020                goto cantfind_ext2;
1021        sbi->s_frags_per_block = sb->s_blocksize / sbi->s_frag_size;
1022
1023        sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
1024        sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
1025        sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
1026
1027        if (EXT2_INODE_SIZE(sb) == 0)
1028                goto cantfind_ext2;
1029        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
1030        if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
1031                goto cantfind_ext2;
1032        sbi->s_itb_per_group = sbi->s_inodes_per_group /
1033                                        sbi->s_inodes_per_block;
1034        sbi->s_desc_per_block = sb->s_blocksize /
1035                                        sizeof (struct ext2_group_desc);
1036        sbi->s_sbh = bh;
1037        sbi->s_mount_state = le16_to_cpu(es->s_state);
1038        sbi->s_addr_per_block_bits =
1039                ilog2 (EXT2_ADDR_PER_BLOCK(sb));
1040        sbi->s_desc_per_block_bits =
1041                ilog2 (EXT2_DESC_PER_BLOCK(sb));
1042
1043        if (sb->s_magic != EXT2_SUPER_MAGIC)
1044                goto cantfind_ext2;
1045
1046        if (sb->s_blocksize != bh->b_size) {
1047                if (!silent)
1048                        ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");
1049                goto failed_mount;
1050        }
1051
1052        if (sb->s_blocksize != sbi->s_frag_size) {
1053                ext2_msg(sb, KERN_ERR,
1054                        "error: fragsize %lu != blocksize %lu"
1055                        "(not supported yet)",
1056                        sbi->s_frag_size, sb->s_blocksize);
1057                goto failed_mount;
1058        }
1059
1060        if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
1061                ext2_msg(sb, KERN_ERR,
1062                        "error: #blocks per group too big: %lu",
1063                        sbi->s_blocks_per_group);
1064                goto failed_mount;
1065        }
1066        if (sbi->s_frags_per_group > sb->s_blocksize * 8) {
1067                ext2_msg(sb, KERN_ERR,
1068                        "error: #fragments per group too big: %lu",
1069                        sbi->s_frags_per_group);
1070                goto failed_mount;
1071        }
1072        if (sbi->s_inodes_per_group > sb->s_blocksize * 8) {
1073                ext2_msg(sb, KERN_ERR,
1074                        "error: #inodes per group too big: %lu",
1075                        sbi->s_inodes_per_group);
1076                goto failed_mount;
1077        }
1078
1079        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
1080                goto cantfind_ext2;
1081        sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
1082                                le32_to_cpu(es->s_first_data_block) - 1)
1083                                        / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
1084        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
1085                   EXT2_DESC_PER_BLOCK(sb);
1086        sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
1087        if (sbi->s_group_desc == NULL) {
1088                ext2_msg(sb, KERN_ERR, "error: not enough memory");
1089                goto failed_mount;
1090        }
1091        bgl_lock_init(sbi->s_blockgroup_lock);
1092        sbi->s_debts = kcalloc(sbi->s_groups_count, sizeof(*sbi->s_debts), GFP_KERNEL);
1093        if (!sbi->s_debts) {
1094                ext2_msg(sb, KERN_ERR, "error: not enough memory");
1095                goto failed_mount_group_desc;
1096        }
1097        for (i = 0; i < db_count; i++) {
1098                block = descriptor_loc(sb, logic_sb_block, i);
1099                sbi->s_group_desc[i] = sb_bread(sb, block);
1100                if (!sbi->s_group_desc[i]) {
1101                        for (j = 0; j < i; j++)
1102                                brelse (sbi->s_group_desc[j]);
1103                        ext2_msg(sb, KERN_ERR,
1104                                "error: unable to read group descriptors");
1105                        goto failed_mount_group_desc;
1106                }
1107        }
1108        if (!ext2_check_descriptors (sb)) {
1109                ext2_msg(sb, KERN_ERR, "group descriptors corrupted");
1110                goto failed_mount2;
1111        }
1112        sbi->s_gdb_count = db_count;
1113        get_random_bytes(&sbi->s_next_generation, sizeof(u32));
1114        spin_lock_init(&sbi->s_next_gen_lock);
1115
1116        /* per fileystem reservation list head & lock */
1117        spin_lock_init(&sbi->s_rsv_window_lock);
1118        sbi->s_rsv_window_root = RB_ROOT;
1119        /*
1120         * Add a single, static dummy reservation to the start of the
1121         * reservation window list --- it gives us a placeholder for
1122         * append-at-start-of-list which makes the allocation logic
1123         * _much_ simpler.
1124         */
1125        sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1126        sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED;
1127        sbi->s_rsv_window_head.rsv_alloc_hit = 0;
1128        sbi->s_rsv_window_head.rsv_goal_size = 0;
1129        ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);
1130
1131        err = percpu_counter_init(&sbi->s_freeblocks_counter,
1132                                ext2_count_free_blocks(sb), GFP_KERNEL);
1133        if (!err) {
1134                err = percpu_counter_init(&sbi->s_freeinodes_counter,
1135                                ext2_count_free_inodes(sb), GFP_KERNEL);
1136        }
1137        if (!err) {
1138                err = percpu_counter_init(&sbi->s_dirs_counter,
1139                                ext2_count_dirs(sb), GFP_KERNEL);
1140        }
1141        if (err) {
1142                ext2_msg(sb, KERN_ERR, "error: insufficient memory");
1143                goto failed_mount3;
1144        }
1145
1146#ifdef CONFIG_EXT2_FS_XATTR
1147        sbi->s_ea_block_cache = ext2_xattr_create_cache();
1148        if (!sbi->s_ea_block_cache) {
1149                ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");
1150                goto failed_mount3;
1151        }
1152#endif
1153        /*
1154         * set up enough so that it can read an inode
1155         */
1156        sb->s_op = &ext2_sops;
1157        sb->s_export_op = &ext2_export_ops;
1158        sb->s_xattr = ext2_xattr_handlers;
1159
1160#ifdef CONFIG_QUOTA
1161        sb->dq_op = &dquot_operations;
1162        sb->s_qcop = &ext2_quotactl_ops;
1163        sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1164#endif
1165
1166        root = ext2_iget(sb, EXT2_ROOT_INO);
1167        if (IS_ERR(root)) {
1168                ret = PTR_ERR(root);
1169                goto failed_mount3;
1170        }
1171        if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1172                iput(root);
1173                ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");
1174                goto failed_mount3;
1175        }
1176
1177        sb->s_root = d_make_root(root);
1178        if (!sb->s_root) {
1179                ext2_msg(sb, KERN_ERR, "error: get root inode failed");
1180                ret = -ENOMEM;
1181                goto failed_mount3;
1182        }
1183        if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
1184                ext2_msg(sb, KERN_WARNING,
1185                        "warning: mounting ext3 filesystem as ext2");
1186        if (ext2_setup_super (sb, es, sb_rdonly(sb)))
1187                sb->s_flags |= SB_RDONLY;
1188        ext2_write_super(sb);
1189        return 0;
1190
1191cantfind_ext2:
1192        if (!silent)
1193                ext2_msg(sb, KERN_ERR,
1194                        "error: can't find an ext2 filesystem on dev %s.",
1195                        sb->s_id);
1196        goto failed_mount;
1197failed_mount3:
1198        if (sbi->s_ea_block_cache)
1199                ext2_xattr_destroy_cache(sbi->s_ea_block_cache);
1200        percpu_counter_destroy(&sbi->s_freeblocks_counter);
1201        percpu_counter_destroy(&sbi->s_freeinodes_counter);
1202        percpu_counter_destroy(&sbi->s_dirs_counter);
1203failed_mount2:
1204        for (i = 0; i < db_count; i++)
1205                brelse(sbi->s_group_desc[i]);
1206failed_mount_group_desc:
1207        kfree(sbi->s_group_desc);
1208        kfree(sbi->s_debts);
1209failed_mount:
1210        brelse(bh);
1211failed_sbi:
1212        sb->s_fs_info = NULL;
1213        kfree(sbi->s_blockgroup_lock);
1214        kfree(sbi);
1215failed:
1216        fs_put_dax(dax_dev);
1217        return ret;
1218}
1219
1220static void ext2_clear_super_error(struct super_block *sb)
1221{
1222        struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;
1223
1224        if (buffer_write_io_error(sbh)) {
1225                /*
1226                 * Oh, dear.  A previous attempt to write the
1227                 * superblock failed.  This could happen because the
1228                 * USB device was yanked out.  Or it could happen to
1229                 * be a transient write error and maybe the block will
1230                 * be remapped.  Nothing we can do but to retry the
1231                 * write and hope for the best.
1232                 */
1233                ext2_msg(sb, KERN_ERR,
1234                       "previous I/O error to superblock detected");
1235                clear_buffer_write_io_error(sbh);
1236                set_buffer_uptodate(sbh);
1237        }
1238}
1239
1240void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,
1241                     int wait)
1242{
1243        ext2_clear_super_error(sb);
1244        spin_lock(&EXT2_SB(sb)->s_lock);
1245        es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));
1246        es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));
1247        es->s_wtime = cpu_to_le32(get_seconds());
1248        /* unlock before we do IO */
1249        spin_unlock(&EXT2_SB(sb)->s_lock);
1250        mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
1251        if (wait)
1252                sync_dirty_buffer(EXT2_SB(sb)->s_sbh);
1253}
1254
1255/*
1256 * In the second extended file system, it is not necessary to
1257 * write the super block since we use a mapping of the
1258 * disk super block in a buffer.
1259 *
1260 * However, this function is still used to set the fs valid
1261 * flags to 0.  We need to set this flag to 0 since the fs
1262 * may have been checked while mounted and e2fsck may have
1263 * set s_state to EXT2_VALID_FS after some corrections.
1264 */
1265static int ext2_sync_fs(struct super_block *sb, int wait)
1266{
1267        struct ext2_sb_info *sbi = EXT2_SB(sb);
1268        struct ext2_super_block *es = EXT2_SB(sb)->s_es;
1269
1270        /*
1271         * Write quota structures to quota file, sync_blockdev() will write
1272         * them to disk later
1273         */
1274        dquot_writeback_dquots(sb, -1);
1275
1276        spin_lock(&sbi->s_lock);
1277        if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
1278                ext2_debug("setting valid to 0\n");
1279                es->s_state &= cpu_to_le16(~EXT2_VALID_FS);
1280        }
1281        spin_unlock(&sbi->s_lock);
1282        ext2_sync_super(sb, es, wait);
1283        return 0;
1284}
1285
1286static int ext2_freeze(struct super_block *sb)
1287{
1288        struct ext2_sb_info *sbi = EXT2_SB(sb);
1289
1290        /*
1291         * Open but unlinked files present? Keep EXT2_VALID_FS flag cleared
1292         * because we have unattached inodes and thus filesystem is not fully
1293         * consistent.
1294         */
1295        if (atomic_long_read(&sb->s_remove_count)) {
1296                ext2_sync_fs(sb, 1);
1297                return 0;
1298        }
1299        /* Set EXT2_FS_VALID flag */
1300        spin_lock(&sbi->s_lock);
1301        sbi->s_es->s_state = cpu_to_le16(sbi->s_mount_state);
1302        spin_unlock(&sbi->s_lock);
1303        ext2_sync_super(sb, sbi->s_es, 1);
1304
1305        return 0;
1306}
1307
1308static int ext2_unfreeze(struct super_block *sb)
1309{
1310        /* Just write sb to clear EXT2_VALID_FS flag */
1311        ext2_write_super(sb);
1312
1313        return 0;
1314}
1315
1316static void ext2_write_super(struct super_block *sb)
1317{
1318        if (!sb_rdonly(sb))
1319                ext2_sync_fs(sb, 1);
1320}
1321
1322static int ext2_remount (struct super_block * sb, int * flags, char * data)
1323{
1324        struct ext2_sb_info * sbi = EXT2_SB(sb);
1325        struct ext2_super_block * es;
1326        struct ext2_mount_options new_opts;
1327        int err;
1328
1329        sync_filesystem(sb);
1330
1331        spin_lock(&sbi->s_lock);
1332        new_opts.s_mount_opt = sbi->s_mount_opt;
1333        new_opts.s_resuid = sbi->s_resuid;
1334        new_opts.s_resgid = sbi->s_resgid;
1335        spin_unlock(&sbi->s_lock);
1336
1337        /*
1338         * Allow the "check" option to be passed as a remount option.
1339         */
1340        if (!parse_options(data, sb, &new_opts))
1341                return -EINVAL;
1342
1343        spin_lock(&sbi->s_lock);
1344        es = sbi->s_es;
1345        if ((sbi->s_mount_opt ^ new_opts.s_mount_opt) & EXT2_MOUNT_DAX) {
1346                ext2_msg(sb, KERN_WARNING, "warning: refusing change of "
1347                         "dax flag with busy inodes while remounting");
1348                new_opts.s_mount_opt ^= EXT2_MOUNT_DAX;
1349        }
1350        if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1351                goto out_set;
1352        if (*flags & SB_RDONLY) {
1353                if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
1354                    !(sbi->s_mount_state & EXT2_VALID_FS))
1355                        goto out_set;
1356
1357                /*
1358                 * OK, we are remounting a valid rw partition rdonly, so set
1359                 * the rdonly flag and then mark the partition as valid again.
1360                 */
1361                es->s_state = cpu_to_le16(sbi->s_mount_state);
1362                es->s_mtime = cpu_to_le32(get_seconds());
1363                spin_unlock(&sbi->s_lock);
1364
1365                err = dquot_suspend(sb, -1);
1366                if (err < 0)
1367                        return err;
1368
1369                ext2_sync_super(sb, es, 1);
1370        } else {
1371                __le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,
1372                                               ~EXT2_FEATURE_RO_COMPAT_SUPP);
1373                if (ret) {
1374                        spin_unlock(&sbi->s_lock);
1375                        ext2_msg(sb, KERN_WARNING,
1376                                "warning: couldn't remount RDWR because of "
1377                                "unsupported optional features (%x).",
1378                                le32_to_cpu(ret));
1379                        return -EROFS;
1380                }
1381                /*
1382                 * Mounting a RDONLY partition read-write, so reread and
1383                 * store the current valid flag.  (It may have been changed
1384                 * by e2fsck since we originally mounted the partition.)
1385                 */
1386                sbi->s_mount_state = le16_to_cpu(es->s_state);
1387                if (!ext2_setup_super (sb, es, 0))
1388                        sb->s_flags &= ~SB_RDONLY;
1389                spin_unlock(&sbi->s_lock);
1390
1391                ext2_write_super(sb);
1392
1393                dquot_resume(sb, -1);
1394        }
1395
1396        spin_lock(&sbi->s_lock);
1397out_set:
1398        sbi->s_mount_opt = new_opts.s_mount_opt;
1399        sbi->s_resuid = new_opts.s_resuid;
1400        sbi->s_resgid = new_opts.s_resgid;
1401        sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
1402                ((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? SB_POSIXACL : 0);
1403        spin_unlock(&sbi->s_lock);
1404
1405        return 0;
1406}
1407
1408static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf)
1409{
1410        struct super_block *sb = dentry->d_sb;
1411        struct ext2_sb_info *sbi = EXT2_SB(sb);
1412        struct ext2_super_block *es = sbi->s_es;
1413        u64 fsid;
1414
1415        spin_lock(&sbi->s_lock);
1416
1417        if (test_opt (sb, MINIX_DF))
1418                sbi->s_overhead_last = 0;
1419        else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) {
1420                unsigned long i, overhead = 0;
1421                smp_rmb();
1422
1423                /*
1424                 * Compute the overhead (FS structures). This is constant
1425                 * for a given filesystem unless the number of block groups
1426                 * changes so we cache the previous value until it does.
1427                 */
1428
1429                /*
1430                 * All of the blocks before first_data_block are
1431                 * overhead
1432                 */
1433                overhead = le32_to_cpu(es->s_first_data_block);
1434
1435                /*
1436                 * Add the overhead attributed to the superblock and
1437                 * block group descriptors.  If the sparse superblocks
1438                 * feature is turned on, then not all groups have this.
1439                 */
1440                for (i = 0; i < sbi->s_groups_count; i++)
1441                        overhead += ext2_bg_has_super(sb, i) +
1442                                ext2_bg_num_gdb(sb, i);
1443
1444                /*
1445                 * Every block group has an inode bitmap, a block
1446                 * bitmap, and an inode table.
1447                 */
1448                overhead += (sbi->s_groups_count *
1449                             (2 + sbi->s_itb_per_group));
1450                sbi->s_overhead_last = overhead;
1451                smp_wmb();
1452                sbi->s_blocks_last = le32_to_cpu(es->s_blocks_count);
1453        }
1454
1455        buf->f_type = EXT2_SUPER_MAGIC;
1456        buf->f_bsize = sb->s_blocksize;
1457        buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
1458        buf->f_bfree = ext2_count_free_blocks(sb);
1459        es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
1460        buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
1461        if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
1462                buf->f_bavail = 0;
1463        buf->f_files = le32_to_cpu(es->s_inodes_count);
1464        buf->f_ffree = ext2_count_free_inodes(sb);
1465        es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);
1466        buf->f_namelen = EXT2_NAME_LEN;
1467        fsid = le64_to_cpup((void *)es->s_uuid) ^
1468               le64_to_cpup((void *)es->s_uuid + sizeof(u64));
1469        buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
1470        buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
1471        spin_unlock(&sbi->s_lock);
1472        return 0;
1473}
1474
1475static struct dentry *ext2_mount(struct file_system_type *fs_type,
1476        int flags, const char *dev_name, void *data)
1477{
1478        return mount_bdev(fs_type, flags, dev_name, data, ext2_fill_super);
1479}
1480
1481#ifdef CONFIG_QUOTA
1482
1483/* Read data from quotafile - avoid pagecache and such because we cannot afford
1484 * acquiring the locks... As quota files are never truncated and quota code
1485 * itself serializes the operations (and no one else should touch the files)
1486 * we don't have to be afraid of races */
1487static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,
1488                               size_t len, loff_t off)
1489{
1490        struct inode *inode = sb_dqopt(sb)->files[type];
1491        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1492        int err = 0;
1493        int offset = off & (sb->s_blocksize - 1);
1494        int tocopy;
1495        size_t toread;
1496        struct buffer_head tmp_bh;
1497        struct buffer_head *bh;
1498        loff_t i_size = i_size_read(inode);
1499
1500        if (off > i_size)
1501                return 0;
1502        if (off+len > i_size)
1503                len = i_size-off;
1504        toread = len;
1505        while (toread > 0) {
1506                tocopy = sb->s_blocksize - offset < toread ?
1507                                sb->s_blocksize - offset : toread;
1508
1509                tmp_bh.b_state = 0;
1510                tmp_bh.b_size = sb->s_blocksize;
1511                err = ext2_get_block(inode, blk, &tmp_bh, 0);
1512                if (err < 0)
1513                        return err;
1514                if (!buffer_mapped(&tmp_bh))    /* A hole? */
1515                        memset(data, 0, tocopy);
1516                else {
1517                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1518                        if (!bh)
1519                                return -EIO;
1520                        memcpy(data, bh->b_data+offset, tocopy);
1521                        brelse(bh);
1522                }
1523                offset = 0;
1524                toread -= tocopy;
1525                data += tocopy;
1526                blk++;
1527        }
1528        return len;
1529}
1530
1531/* Write to quotafile */
1532static ssize_t ext2_quota_write(struct super_block *sb, int type,
1533                                const char *data, size_t len, loff_t off)
1534{
1535        struct inode *inode = sb_dqopt(sb)->files[type];
1536        sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);
1537        int err = 0;
1538        int offset = off & (sb->s_blocksize - 1);
1539        int tocopy;
1540        size_t towrite = len;
1541        struct buffer_head tmp_bh;
1542        struct buffer_head *bh;
1543
1544        while (towrite > 0) {
1545                tocopy = sb->s_blocksize - offset < towrite ?
1546                                sb->s_blocksize - offset : towrite;
1547
1548                tmp_bh.b_state = 0;
1549                tmp_bh.b_size = sb->s_blocksize;
1550                err = ext2_get_block(inode, blk, &tmp_bh, 1);
1551                if (err < 0)
1552                        goto out;
1553                if (offset || tocopy != EXT2_BLOCK_SIZE(sb))
1554                        bh = sb_bread(sb, tmp_bh.b_blocknr);
1555                else
1556                        bh = sb_getblk(sb, tmp_bh.b_blocknr);
1557                if (unlikely(!bh)) {
1558                        err = -EIO;
1559                        goto out;
1560                }
1561                lock_buffer(bh);
1562                memcpy(bh->b_data+offset, data, tocopy);
1563                flush_dcache_page(bh->b_page);
1564                set_buffer_uptodate(bh);
1565                mark_buffer_dirty(bh);
1566                unlock_buffer(bh);
1567                brelse(bh);
1568                offset = 0;
1569                towrite -= tocopy;
1570                data += tocopy;
1571                blk++;
1572        }
1573out:
1574        if (len == towrite)
1575                return err;
1576        if (inode->i_size < off+len-towrite)
1577                i_size_write(inode, off+len-towrite);
1578        inode_inc_iversion(inode);
1579        inode->i_mtime = inode->i_ctime = current_time(inode);
1580        mark_inode_dirty(inode);
1581        return len - towrite;
1582}
1583
1584static int ext2_quota_on(struct super_block *sb, int type, int format_id,
1585                         const struct path *path)
1586{
1587        int err;
1588        struct inode *inode;
1589
1590        err = dquot_quota_on(sb, type, format_id, path);
1591        if (err)
1592                return err;
1593
1594        inode = d_inode(path->dentry);
1595        inode_lock(inode);
1596        EXT2_I(inode)->i_flags |= EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL;
1597        inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
1598                        S_NOATIME | S_IMMUTABLE);
1599        inode_unlock(inode);
1600        mark_inode_dirty(inode);
1601
1602        return 0;
1603}
1604
1605static int ext2_quota_off(struct super_block *sb, int type)
1606{
1607        struct inode *inode = sb_dqopt(sb)->files[type];
1608        int err;
1609
1610        if (!inode || !igrab(inode))
1611                goto out;
1612
1613        err = dquot_quota_off(sb, type);
1614        if (err)
1615                goto out_put;
1616
1617        inode_lock(inode);
1618        EXT2_I(inode)->i_flags &= ~(EXT2_NOATIME_FL | EXT2_IMMUTABLE_FL);
1619        inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
1620        inode_unlock(inode);
1621        mark_inode_dirty(inode);
1622out_put:
1623        iput(inode);
1624        return err;
1625out:
1626        return dquot_quota_off(sb, type);
1627}
1628
1629#endif
1630
1631static struct file_system_type ext2_fs_type = {
1632        .owner          = THIS_MODULE,
1633        .name           = "ext2",
1634        .mount          = ext2_mount,
1635        .kill_sb        = kill_block_super,
1636        .fs_flags       = FS_REQUIRES_DEV,
1637};
1638MODULE_ALIAS_FS("ext2");
1639
1640static int __init init_ext2_fs(void)
1641{
1642        int err;
1643
1644        err = init_inodecache();
1645        if (err)
1646                return err;
1647        err = register_filesystem(&ext2_fs_type);
1648        if (err)
1649                goto out;
1650        return 0;
1651out:
1652        destroy_inodecache();
1653        return err;
1654}
1655
1656static void __exit exit_ext2_fs(void)
1657{
1658        unregister_filesystem(&ext2_fs_type);
1659        destroy_inodecache();
1660}
1661
1662MODULE_AUTHOR("Remy Card and others");
1663MODULE_DESCRIPTION("Second Extended Filesystem");
1664MODULE_LICENSE("GPL");
1665module_init(init_ext2_fs)
1666module_exit(exit_ext2_fs)
1667