linux/fs/exfat/super.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
   4 */
   5
   6#include <linux/fs_context.h>
   7#include <linux/fs_parser.h>
   8#include <linux/module.h>
   9#include <linux/init.h>
  10#include <linux/time.h>
  11#include <linux/mount.h>
  12#include <linux/cred.h>
  13#include <linux/statfs.h>
  14#include <linux/seq_file.h>
  15#include <linux/blkdev.h>
  16#include <linux/fs_struct.h>
  17#include <linux/iversion.h>
  18#include <linux/nls.h>
  19#include <linux/buffer_head.h>
  20#include <linux/magic.h>
  21
  22#include "exfat_raw.h"
  23#include "exfat_fs.h"
  24
  25static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
  26static struct kmem_cache *exfat_inode_cachep;
  27
  28static void exfat_free_iocharset(struct exfat_sb_info *sbi)
  29{
  30        if (sbi->options.iocharset != exfat_default_iocharset)
  31                kfree(sbi->options.iocharset);
  32}
  33
  34static void exfat_delayed_free(struct rcu_head *p)
  35{
  36        struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);
  37
  38        unload_nls(sbi->nls_io);
  39        exfat_free_iocharset(sbi);
  40        exfat_free_upcase_table(sbi);
  41        kfree(sbi);
  42}
  43
  44static void exfat_put_super(struct super_block *sb)
  45{
  46        struct exfat_sb_info *sbi = EXFAT_SB(sb);
  47
  48        mutex_lock(&sbi->s_lock);
  49        exfat_free_bitmap(sbi);
  50        brelse(sbi->boot_bh);
  51        mutex_unlock(&sbi->s_lock);
  52
  53        call_rcu(&sbi->rcu, exfat_delayed_free);
  54}
  55
  56static int exfat_sync_fs(struct super_block *sb, int wait)
  57{
  58        struct exfat_sb_info *sbi = EXFAT_SB(sb);
  59        int err = 0;
  60
  61        if (!wait)
  62                return 0;
  63
  64        /* If there are some dirty buffers in the bdev inode */
  65        mutex_lock(&sbi->s_lock);
  66        sync_blockdev(sb->s_bdev);
  67        if (exfat_clear_volume_dirty(sb))
  68                err = -EIO;
  69        mutex_unlock(&sbi->s_lock);
  70        return err;
  71}
  72
  73static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
  74{
  75        struct super_block *sb = dentry->d_sb;
  76        struct exfat_sb_info *sbi = EXFAT_SB(sb);
  77        unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);
  78
  79        if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
  80                mutex_lock(&sbi->s_lock);
  81                if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
  82                        mutex_unlock(&sbi->s_lock);
  83                        return -EIO;
  84                }
  85                mutex_unlock(&sbi->s_lock);
  86        }
  87
  88        buf->f_type = sb->s_magic;
  89        buf->f_bsize = sbi->cluster_size;
  90        buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
  91        buf->f_bfree = buf->f_blocks - sbi->used_clusters;
  92        buf->f_bavail = buf->f_bfree;
  93        buf->f_fsid = u64_to_fsid(id);
  94        /* Unicode utf16 255 characters */
  95        buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
  96        return 0;
  97}
  98
  99static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
 100{
 101        struct exfat_sb_info *sbi = EXFAT_SB(sb);
 102        struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
 103
 104        /* retain persistent-flags */
 105        new_flags |= sbi->vol_flags_persistent;
 106
 107        /* flags are not changed */
 108        if (sbi->vol_flags == new_flags)
 109                return 0;
 110
 111        sbi->vol_flags = new_flags;
 112
 113        /* skip updating volume dirty flag,
 114         * if this volume has been mounted with read-only
 115         */
 116        if (sb_rdonly(sb))
 117                return 0;
 118
 119        p_boot->vol_flags = cpu_to_le16(new_flags);
 120
 121        set_buffer_uptodate(sbi->boot_bh);
 122        mark_buffer_dirty(sbi->boot_bh);
 123
 124        __sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);
 125
 126        return 0;
 127}
 128
 129int exfat_set_volume_dirty(struct super_block *sb)
 130{
 131        struct exfat_sb_info *sbi = EXFAT_SB(sb);
 132
 133        return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY);
 134}
 135
 136int exfat_clear_volume_dirty(struct super_block *sb)
 137{
 138        struct exfat_sb_info *sbi = EXFAT_SB(sb);
 139
 140        return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY);
 141}
 142
 143static int exfat_show_options(struct seq_file *m, struct dentry *root)
 144{
 145        struct super_block *sb = root->d_sb;
 146        struct exfat_sb_info *sbi = EXFAT_SB(sb);
 147        struct exfat_mount_options *opts = &sbi->options;
 148
 149        /* Show partition info */
 150        if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
 151                seq_printf(m, ",uid=%u",
 152                                from_kuid_munged(&init_user_ns, opts->fs_uid));
 153        if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
 154                seq_printf(m, ",gid=%u",
 155                                from_kgid_munged(&init_user_ns, opts->fs_gid));
 156        seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
 157        if (opts->allow_utime)
 158                seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
 159        if (opts->utf8)
 160                seq_puts(m, ",iocharset=utf8");
 161        else if (sbi->nls_io)
 162                seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
 163        if (opts->errors == EXFAT_ERRORS_CONT)
 164                seq_puts(m, ",errors=continue");
 165        else if (opts->errors == EXFAT_ERRORS_PANIC)
 166                seq_puts(m, ",errors=panic");
 167        else
 168                seq_puts(m, ",errors=remount-ro");
 169        if (opts->discard)
 170                seq_puts(m, ",discard");
 171        if (opts->keep_last_dots)
 172                seq_puts(m, ",keep_last_dots");
 173        if (opts->sys_tz)
 174                seq_puts(m, ",sys_tz");
 175        else if (opts->time_offset)
 176                seq_printf(m, ",time_offset=%d", opts->time_offset);
 177        return 0;
 178}
 179
 180static struct inode *exfat_alloc_inode(struct super_block *sb)
 181{
 182        struct exfat_inode_info *ei;
 183
 184        ei = alloc_inode_sb(sb, exfat_inode_cachep, GFP_NOFS);
 185        if (!ei)
 186                return NULL;
 187
 188        init_rwsem(&ei->truncate_lock);
 189        return &ei->vfs_inode;
 190}
 191
 192static void exfat_free_inode(struct inode *inode)
 193{
 194        kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
 195}
 196
 197static const struct super_operations exfat_sops = {
 198        .alloc_inode    = exfat_alloc_inode,
 199        .free_inode     = exfat_free_inode,
 200        .write_inode    = exfat_write_inode,
 201        .evict_inode    = exfat_evict_inode,
 202        .put_super      = exfat_put_super,
 203        .sync_fs        = exfat_sync_fs,
 204        .statfs         = exfat_statfs,
 205        .show_options   = exfat_show_options,
 206};
 207
 208enum {
 209        Opt_uid,
 210        Opt_gid,
 211        Opt_umask,
 212        Opt_dmask,
 213        Opt_fmask,
 214        Opt_allow_utime,
 215        Opt_charset,
 216        Opt_errors,
 217        Opt_discard,
 218        Opt_keep_last_dots,
 219        Opt_sys_tz,
 220        Opt_time_offset,
 221
 222        /* Deprecated options */
 223        Opt_utf8,
 224        Opt_debug,
 225        Opt_namecase,
 226        Opt_codepage,
 227};
 228
 229static const struct constant_table exfat_param_enums[] = {
 230        { "continue",           EXFAT_ERRORS_CONT },
 231        { "panic",              EXFAT_ERRORS_PANIC },
 232        { "remount-ro",         EXFAT_ERRORS_RO },
 233        {}
 234};
 235
 236static const struct fs_parameter_spec exfat_parameters[] = {
 237        fsparam_u32("uid",                      Opt_uid),
 238        fsparam_u32("gid",                      Opt_gid),
 239        fsparam_u32oct("umask",                 Opt_umask),
 240        fsparam_u32oct("dmask",                 Opt_dmask),
 241        fsparam_u32oct("fmask",                 Opt_fmask),
 242        fsparam_u32oct("allow_utime",           Opt_allow_utime),
 243        fsparam_string("iocharset",             Opt_charset),
 244        fsparam_enum("errors",                  Opt_errors, exfat_param_enums),
 245        fsparam_flag("discard",                 Opt_discard),
 246        fsparam_flag("keep_last_dots",          Opt_keep_last_dots),
 247        fsparam_flag("sys_tz",                  Opt_sys_tz),
 248        fsparam_s32("time_offset",              Opt_time_offset),
 249        __fsparam(NULL, "utf8",                 Opt_utf8, fs_param_deprecated,
 250                  NULL),
 251        __fsparam(NULL, "debug",                Opt_debug, fs_param_deprecated,
 252                  NULL),
 253        __fsparam(fs_param_is_u32, "namecase",  Opt_namecase,
 254                  fs_param_deprecated, NULL),
 255        __fsparam(fs_param_is_u32, "codepage",  Opt_codepage,
 256                  fs_param_deprecated, NULL),
 257        {}
 258};
 259
 260static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
 261{
 262        struct exfat_sb_info *sbi = fc->s_fs_info;
 263        struct exfat_mount_options *opts = &sbi->options;
 264        struct fs_parse_result result;
 265        int opt;
 266
 267        opt = fs_parse(fc, exfat_parameters, param, &result);
 268        if (opt < 0)
 269                return opt;
 270
 271        switch (opt) {
 272        case Opt_uid:
 273                opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
 274                break;
 275        case Opt_gid:
 276                opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
 277                break;
 278        case Opt_umask:
 279                opts->fs_fmask = result.uint_32;
 280                opts->fs_dmask = result.uint_32;
 281                break;
 282        case Opt_dmask:
 283                opts->fs_dmask = result.uint_32;
 284                break;
 285        case Opt_fmask:
 286                opts->fs_fmask = result.uint_32;
 287                break;
 288        case Opt_allow_utime:
 289                opts->allow_utime = result.uint_32 & 0022;
 290                break;
 291        case Opt_charset:
 292                exfat_free_iocharset(sbi);
 293                opts->iocharset = param->string;
 294                param->string = NULL;
 295                break;
 296        case Opt_errors:
 297                opts->errors = result.uint_32;
 298                break;
 299        case Opt_discard:
 300                opts->discard = 1;
 301                break;
 302        case Opt_keep_last_dots:
 303                opts->keep_last_dots = 1;
 304                break;
 305        case Opt_sys_tz:
 306                opts->sys_tz = 1;
 307                break;
 308        case Opt_time_offset:
 309                /*
 310                 * Make the limit 24 just in case someone invents something
 311                 * unusual.
 312                 */
 313                if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
 314                        return -EINVAL;
 315                opts->time_offset = result.int_32;
 316                break;
 317        case Opt_utf8:
 318        case Opt_debug:
 319        case Opt_namecase:
 320        case Opt_codepage:
 321                break;
 322        default:
 323                return -EINVAL;
 324        }
 325
 326        return 0;
 327}
 328
 329static void exfat_hash_init(struct super_block *sb)
 330{
 331        struct exfat_sb_info *sbi = EXFAT_SB(sb);
 332        int i;
 333
 334        spin_lock_init(&sbi->inode_hash_lock);
 335        for (i = 0; i < EXFAT_HASH_SIZE; i++)
 336                INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
 337}
 338
 339static int exfat_read_root(struct inode *inode)
 340{
 341        struct super_block *sb = inode->i_sb;
 342        struct exfat_sb_info *sbi = EXFAT_SB(sb);
 343        struct exfat_inode_info *ei = EXFAT_I(inode);
 344        struct exfat_chain cdir;
 345        int num_subdirs, num_clu = 0;
 346
 347        exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
 348        ei->entry = -1;
 349        ei->start_clu = sbi->root_dir;
 350        ei->flags = ALLOC_FAT_CHAIN;
 351        ei->type = TYPE_DIR;
 352        ei->version = 0;
 353        ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
 354        ei->hint_stat.eidx = 0;
 355        ei->hint_stat.clu = sbi->root_dir;
 356        ei->hint_femp.eidx = EXFAT_HINT_NONE;
 357
 358        exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
 359        if (exfat_count_num_clusters(sb, &cdir, &num_clu))
 360                return -EIO;
 361        i_size_write(inode, num_clu << sbi->cluster_size_bits);
 362
 363        num_subdirs = exfat_count_dir_entries(sb, &cdir);
 364        if (num_subdirs < 0)
 365                return -EIO;
 366        set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);
 367
 368        inode->i_uid = sbi->options.fs_uid;
 369        inode->i_gid = sbi->options.fs_gid;
 370        inode_inc_iversion(inode);
 371        inode->i_generation = 0;
 372        inode->i_mode = exfat_make_mode(sbi, ATTR_SUBDIR, 0777);
 373        inode->i_op = &exfat_dir_inode_operations;
 374        inode->i_fop = &exfat_dir_operations;
 375
 376        inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >>
 377                                inode->i_blkbits;
 378        ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;
 379        ei->i_size_aligned = i_size_read(inode);
 380        ei->i_size_ondisk = i_size_read(inode);
 381
 382        exfat_save_attr(inode, ATTR_SUBDIR);
 383        inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
 384                current_time(inode);
 385        exfat_truncate_atime(&inode->i_atime);
 386        return 0;
 387}
 388
 389static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)
 390{
 391        struct exfat_sb_info *sbi = EXFAT_SB(sb);
 392
 393        if (!is_power_of_2(logical_sect)) {
 394                exfat_err(sb, "bogus logical sector size %u", logical_sect);
 395                return -EIO;
 396        }
 397
 398        if (logical_sect < sb->s_blocksize) {
 399                exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",
 400                          logical_sect);
 401                return -EIO;
 402        }
 403
 404        if (logical_sect > sb->s_blocksize) {
 405                brelse(sbi->boot_bh);
 406                sbi->boot_bh = NULL;
 407
 408                if (!sb_set_blocksize(sb, logical_sect)) {
 409                        exfat_err(sb, "unable to set blocksize %u",
 410                                  logical_sect);
 411                        return -EIO;
 412                }
 413                sbi->boot_bh = sb_bread(sb, 0);
 414                if (!sbi->boot_bh) {
 415                        exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
 416                                  sb->s_blocksize);
 417                        return -EIO;
 418                }
 419        }
 420        return 0;
 421}
 422
 423static int exfat_read_boot_sector(struct super_block *sb)
 424{
 425        struct boot_sector *p_boot;
 426        struct exfat_sb_info *sbi = EXFAT_SB(sb);
 427
 428        /* set block size to read super block */
 429        sb_min_blocksize(sb, 512);
 430
 431        /* read boot sector */
 432        sbi->boot_bh = sb_bread(sb, 0);
 433        if (!sbi->boot_bh) {
 434                exfat_err(sb, "unable to read boot sector");
 435                return -EIO;
 436        }
 437        p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
 438
 439        /* check the validity of BOOT */
 440        if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {
 441                exfat_err(sb, "invalid boot record signature");
 442                return -EINVAL;
 443        }
 444
 445        if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) {
 446                exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */
 447                return -EINVAL;
 448        }
 449
 450        /*
 451         * must_be_zero field must be filled with zero to prevent mounting
 452         * from FAT volume.
 453         */
 454        if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))
 455                return -EINVAL;
 456
 457        if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {
 458                exfat_err(sb, "bogus number of FAT structure");
 459                return -EINVAL;
 460        }
 461
 462        /*
 463         * sect_size_bits could be at least 9 and at most 12.
 464         */
 465        if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS ||
 466            p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) {
 467                exfat_err(sb, "bogus sector size bits : %u\n",
 468                                p_boot->sect_size_bits);
 469                return -EINVAL;
 470        }
 471
 472        /*
 473         * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits.
 474         */
 475        if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) {
 476                exfat_err(sb, "bogus sectors bits per cluster : %u\n",
 477                                p_boot->sect_per_clus_bits);
 478                return -EINVAL;
 479        }
 480
 481        sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
 482        sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;
 483        sbi->cluster_size_bits = p_boot->sect_per_clus_bits +
 484                p_boot->sect_size_bits;
 485        sbi->cluster_size = 1 << sbi->cluster_size_bits;
 486        sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
 487        sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);
 488        sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);
 489        if (p_boot->num_fats == 2)
 490                sbi->FAT2_start_sector += sbi->num_FAT_sectors;
 491        sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
 492        sbi->num_sectors = le64_to_cpu(p_boot->vol_length);
 493        /* because the cluster index starts with 2 */
 494        sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +
 495                EXFAT_RESERVED_CLUSTERS;
 496
 497        sbi->root_dir = le32_to_cpu(p_boot->root_cluster);
 498        sbi->dentries_per_clu = 1 <<
 499                (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
 500
 501        sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);
 502        sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);
 503        sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
 504        sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
 505
 506        /* check consistencies */
 507        if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits <
 508            (u64)sbi->num_clusters * 4) {
 509                exfat_err(sb, "bogus fat length");
 510                return -EINVAL;
 511        }
 512
 513        if (sbi->data_start_sector <
 514            (u64)sbi->FAT1_start_sector +
 515            (u64)sbi->num_FAT_sectors * p_boot->num_fats) {
 516                exfat_err(sb, "bogus data start sector");
 517                return -EINVAL;
 518        }
 519
 520        if (sbi->vol_flags & VOLUME_DIRTY)
 521                exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
 522        if (sbi->vol_flags & MEDIA_FAILURE)
 523                exfat_warn(sb, "Medium has reported failures. Some data may be lost.");
 524
 525        /* exFAT file size is limited by a disk volume size */
 526        sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
 527                sbi->cluster_size_bits;
 528
 529        /* check logical sector size */
 530        if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
 531                return -EIO;
 532
 533        return 0;
 534}
 535
 536static int exfat_verify_boot_region(struct super_block *sb)
 537{
 538        struct buffer_head *bh = NULL;
 539        u32 chksum = 0;
 540        __le32 *p_sig, *p_chksum;
 541        int sn, i;
 542
 543        /* read boot sector sub-regions */
 544        for (sn = 0; sn < 11; sn++) {
 545                bh = sb_bread(sb, sn);
 546                if (!bh)
 547                        return -EIO;
 548
 549                if (sn != 0 && sn <= 8) {
 550                        /* extended boot sector sub-regions */
 551                        p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4];
 552                        if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)
 553                                exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",
 554                                           sn, le32_to_cpu(*p_sig));
 555                }
 556
 557                chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
 558                        chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
 559                brelse(bh);
 560        }
 561
 562        /* boot checksum sub-regions */
 563        bh = sb_bread(sb, sn);
 564        if (!bh)
 565                return -EIO;
 566
 567        for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
 568                p_chksum = (__le32 *)&bh->b_data[i];
 569                if (le32_to_cpu(*p_chksum) != chksum) {
 570                        exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",
 571                                  le32_to_cpu(*p_chksum), chksum);
 572                        brelse(bh);
 573                        return -EINVAL;
 574                }
 575        }
 576        brelse(bh);
 577        return 0;
 578}
 579
 580/* mount the file system volume */
 581static int __exfat_fill_super(struct super_block *sb)
 582{
 583        int ret;
 584        struct exfat_sb_info *sbi = EXFAT_SB(sb);
 585
 586        ret = exfat_read_boot_sector(sb);
 587        if (ret) {
 588                exfat_err(sb, "failed to read boot sector");
 589                goto free_bh;
 590        }
 591
 592        ret = exfat_verify_boot_region(sb);
 593        if (ret) {
 594                exfat_err(sb, "invalid boot region");
 595                goto free_bh;
 596        }
 597
 598        ret = exfat_create_upcase_table(sb);
 599        if (ret) {
 600                exfat_err(sb, "failed to load upcase table");
 601                goto free_bh;
 602        }
 603
 604        ret = exfat_load_bitmap(sb);
 605        if (ret) {
 606                exfat_err(sb, "failed to load alloc-bitmap");
 607                goto free_upcase_table;
 608        }
 609
 610        ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
 611        if (ret) {
 612                exfat_err(sb, "failed to scan clusters");
 613                goto free_alloc_bitmap;
 614        }
 615
 616        return 0;
 617
 618free_alloc_bitmap:
 619        exfat_free_bitmap(sbi);
 620free_upcase_table:
 621        exfat_free_upcase_table(sbi);
 622free_bh:
 623        brelse(sbi->boot_bh);
 624        return ret;
 625}
 626
 627static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
 628{
 629        struct exfat_sb_info *sbi = sb->s_fs_info;
 630        struct exfat_mount_options *opts = &sbi->options;
 631        struct inode *root_inode;
 632        int err;
 633
 634        if (opts->allow_utime == (unsigned short)-1)
 635                opts->allow_utime = ~opts->fs_dmask & 0022;
 636
 637        if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) {
 638                exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard");
 639                opts->discard = 0;
 640        }
 641
 642        sb->s_flags |= SB_NODIRATIME;
 643        sb->s_magic = EXFAT_SUPER_MAGIC;
 644        sb->s_op = &exfat_sops;
 645
 646        sb->s_time_gran = 10 * NSEC_PER_MSEC;
 647        sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
 648        sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
 649
 650        err = __exfat_fill_super(sb);
 651        if (err) {
 652                exfat_err(sb, "failed to recognize exfat type");
 653                goto check_nls_io;
 654        }
 655
 656        /* set up enough so that it can read an inode */
 657        exfat_hash_init(sb);
 658
 659        if (!strcmp(sbi->options.iocharset, "utf8"))
 660                opts->utf8 = 1;
 661        else {
 662                sbi->nls_io = load_nls(sbi->options.iocharset);
 663                if (!sbi->nls_io) {
 664                        exfat_err(sb, "IO charset %s not found",
 665                                  sbi->options.iocharset);
 666                        err = -EINVAL;
 667                        goto free_table;
 668                }
 669        }
 670
 671        if (sbi->options.utf8)
 672                sb->s_d_op = &exfat_utf8_dentry_ops;
 673        else
 674                sb->s_d_op = &exfat_dentry_ops;
 675
 676        root_inode = new_inode(sb);
 677        if (!root_inode) {
 678                exfat_err(sb, "failed to allocate root inode");
 679                err = -ENOMEM;
 680                goto free_table;
 681        }
 682
 683        root_inode->i_ino = EXFAT_ROOT_INO;
 684        inode_set_iversion(root_inode, 1);
 685        err = exfat_read_root(root_inode);
 686        if (err) {
 687                exfat_err(sb, "failed to initialize root inode");
 688                goto put_inode;
 689        }
 690
 691        exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
 692        insert_inode_hash(root_inode);
 693
 694        sb->s_root = d_make_root(root_inode);
 695        if (!sb->s_root) {
 696                exfat_err(sb, "failed to get the root dentry");
 697                err = -ENOMEM;
 698                goto free_table;
 699        }
 700
 701        return 0;
 702
 703put_inode:
 704        iput(root_inode);
 705        sb->s_root = NULL;
 706
 707free_table:
 708        exfat_free_upcase_table(sbi);
 709        exfat_free_bitmap(sbi);
 710        brelse(sbi->boot_bh);
 711
 712check_nls_io:
 713        unload_nls(sbi->nls_io);
 714        exfat_free_iocharset(sbi);
 715        sb->s_fs_info = NULL;
 716        kfree(sbi);
 717        return err;
 718}
 719
 720static int exfat_get_tree(struct fs_context *fc)
 721{
 722        return get_tree_bdev(fc, exfat_fill_super);
 723}
 724
 725static void exfat_free(struct fs_context *fc)
 726{
 727        struct exfat_sb_info *sbi = fc->s_fs_info;
 728
 729        if (sbi) {
 730                exfat_free_iocharset(sbi);
 731                kfree(sbi);
 732        }
 733}
 734
 735static int exfat_reconfigure(struct fs_context *fc)
 736{
 737        fc->sb_flags |= SB_NODIRATIME;
 738
 739        /* volume flag will be updated in exfat_sync_fs */
 740        sync_filesystem(fc->root->d_sb);
 741        return 0;
 742}
 743
 744static const struct fs_context_operations exfat_context_ops = {
 745        .parse_param    = exfat_parse_param,
 746        .get_tree       = exfat_get_tree,
 747        .free           = exfat_free,
 748        .reconfigure    = exfat_reconfigure,
 749};
 750
 751static int exfat_init_fs_context(struct fs_context *fc)
 752{
 753        struct exfat_sb_info *sbi;
 754
 755        sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
 756        if (!sbi)
 757                return -ENOMEM;
 758
 759        mutex_init(&sbi->s_lock);
 760        mutex_init(&sbi->bitmap_lock);
 761        ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
 762                        DEFAULT_RATELIMIT_BURST);
 763
 764        sbi->options.fs_uid = current_uid();
 765        sbi->options.fs_gid = current_gid();
 766        sbi->options.fs_fmask = current->fs->umask;
 767        sbi->options.fs_dmask = current->fs->umask;
 768        sbi->options.allow_utime = -1;
 769        sbi->options.iocharset = exfat_default_iocharset;
 770        sbi->options.errors = EXFAT_ERRORS_RO;
 771
 772        fc->s_fs_info = sbi;
 773        fc->ops = &exfat_context_ops;
 774        return 0;
 775}
 776
 777static struct file_system_type exfat_fs_type = {
 778        .owner                  = THIS_MODULE,
 779        .name                   = "exfat",
 780        .init_fs_context        = exfat_init_fs_context,
 781        .parameters             = exfat_parameters,
 782        .kill_sb                = kill_block_super,
 783        .fs_flags               = FS_REQUIRES_DEV,
 784};
 785
 786static void exfat_inode_init_once(void *foo)
 787{
 788        struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;
 789
 790        spin_lock_init(&ei->cache_lru_lock);
 791        ei->nr_caches = 0;
 792        ei->cache_valid_id = EXFAT_CACHE_VALID + 1;
 793        INIT_LIST_HEAD(&ei->cache_lru);
 794        INIT_HLIST_NODE(&ei->i_hash_fat);
 795        inode_init_once(&ei->vfs_inode);
 796}
 797
 798static int __init init_exfat_fs(void)
 799{
 800        int err;
 801
 802        err = exfat_cache_init();
 803        if (err)
 804                return err;
 805
 806        exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
 807                        sizeof(struct exfat_inode_info),
 808                        0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
 809                        exfat_inode_init_once);
 810        if (!exfat_inode_cachep) {
 811                err = -ENOMEM;
 812                goto shutdown_cache;
 813        }
 814
 815        err = register_filesystem(&exfat_fs_type);
 816        if (err)
 817                goto destroy_cache;
 818
 819        return 0;
 820
 821destroy_cache:
 822        kmem_cache_destroy(exfat_inode_cachep);
 823shutdown_cache:
 824        exfat_cache_shutdown();
 825        return err;
 826}
 827
 828static void __exit exit_exfat_fs(void)
 829{
 830        /*
 831         * Make sure all delayed rcu free inodes are flushed before we
 832         * destroy cache.
 833         */
 834        rcu_barrier();
 835        kmem_cache_destroy(exfat_inode_cachep);
 836        unregister_filesystem(&exfat_fs_type);
 837        exfat_cache_shutdown();
 838}
 839
 840module_init(init_exfat_fs);
 841module_exit(exit_exfat_fs);
 842
 843MODULE_ALIAS_FS("exfat");
 844MODULE_LICENSE("GPL");
 845MODULE_DESCRIPTION("exFAT filesystem support");
 846MODULE_AUTHOR("Samsung Electronics Co., Ltd.");
 847