fs/exfat/super.c

   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
  21 #include "exfat_raw.h"
  22 #include "exfat_fs.h"
  23
  24 static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
  25 static struct kmem_cache *exfat_inode_cachep;
  26
  27 static void exfat_free_iocharset(struct exfat_sb_info *sbi)
  28 {
  29         if (sbi->options.iocharset != exfat_default_iocharset)
  30                 kfree(sbi->options.iocharset);
  31 }
  32
  33 static void exfat_delayed_free(struct rcu_head *p)
  34 {
  35         struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);
  36
  37         unload_nls(sbi->nls_io);
  38         exfat_free_iocharset(sbi);
  39         exfat_free_upcase_table(sbi);
  40         kfree(sbi);
  41 }
  42
  43 static void exfat_put_super(struct super_block *sb)
  44 {
  45         struct exfat_sb_info *sbi = EXFAT_SB(sb);
  46
  47         mutex_lock(&sbi->s_lock);
  48         if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state))
  49                 sync_blockdev(sb->s_bdev);
  50         exfat_set_vol_flags(sb, VOL_CLEAN);
  51         exfat_free_bitmap(sbi);
  52         brelse(sbi->pbr_bh);
  53         mutex_unlock(&sbi->s_lock);
  54
  55         call_rcu(&sbi->rcu, exfat_delayed_free);
  56 }
  57
  58 static int exfat_sync_fs(struct super_block *sb, int wait)
  59 {
  60         struct exfat_sb_info *sbi = EXFAT_SB(sb);
  61         int err = 0;
  62
  63         /* If there are some dirty buffers in the bdev inode */
  64         mutex_lock(&sbi->s_lock);
  65         if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state)) {
  66                 sync_blockdev(sb->s_bdev);
  67                 if (exfat_set_vol_flags(sb, VOL_CLEAN))
  68                         err = -EIO;
  69         }
  70         mutex_unlock(&sbi->s_lock);
  71         return err;
  72 }
  73
  74 static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
  75 {
  76         struct super_block *sb = dentry->d_sb;
  77         struct exfat_sb_info *sbi = EXFAT_SB(sb);
  78         unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);
  79
  80         if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
  81                 mutex_lock(&sbi->s_lock);
  82                 if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
  83                         mutex_unlock(&sbi->s_lock);
  84                         return -EIO;
  85                 }
  86                 mutex_unlock(&sbi->s_lock);
  87         }
  88
  89         buf->f_type = sb->s_magic;
  90         buf->f_bsize = sbi->cluster_size;
  91         buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
  92         buf->f_bfree = buf->f_blocks - sbi->used_clusters;
  93         buf->f_bavail = buf->f_bfree;
  94         buf->f_fsid.val[0] = (unsigned int)id;
  95         buf->f_fsid.val[1] = (unsigned int)(id >> 32);
  96         /* Unicode utf16 255 characters */
  97         buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
  98         return 0;
  99 }
 100
 101 int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flag)
 102 {
 103         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 104         struct pbr64 *bpb = (struct pbr64 *)sbi->pbr_bh->b_data;
 105         bool sync = 0;
 106
 107         /* flags are not changed */
 108         if (sbi->vol_flag == new_flag)
 109                 return 0;
 110
 111         sbi->vol_flag = new_flag;
 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         bpb->bsx.vol_flags = cpu_to_le16(new_flag);
 120
 121         if (new_flag == VOL_DIRTY && !buffer_dirty(sbi->pbr_bh))
 122                 sync = true;
 123         else
 124                 sync = false;
 125
 126         set_buffer_uptodate(sbi->pbr_bh);
 127         mark_buffer_dirty(sbi->pbr_bh);
 128
 129         if (sync)
 130                 sync_dirty_buffer(sbi->pbr_bh);
 131         return 0;
 132 }
 133
 134 static int exfat_show_options(struct seq_file *m, struct dentry *root)
 135 {
 136         struct super_block *sb = root->d_sb;
 137         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 138         struct exfat_mount_options *opts = &sbi->options;
 139
 140         /* Show partition info */
 141         if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
 142                 seq_printf(m, ",uid=%u",
 143                                 from_kuid_munged(&init_user_ns, opts->fs_uid));
 144         if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
 145                 seq_printf(m, ",gid=%u",
 146                                 from_kgid_munged(&init_user_ns, opts->fs_gid));
 147         seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
 148         if (opts->allow_utime)
 149                 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
 150         if (opts->utf8)
 151                 seq_puts(m, ",iocharset=utf8");
 152         else if (sbi->nls_io)
 153                 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
 154         if (opts->errors == EXFAT_ERRORS_CONT)
 155                 seq_puts(m, ",errors=continue");
 156         else if (opts->errors == EXFAT_ERRORS_PANIC)
 157                 seq_puts(m, ",errors=panic");
 158         else
 159                 seq_puts(m, ",errors=remount-ro");
 160         if (opts->discard)
 161                 seq_puts(m, ",discard");
 162         if (opts->time_offset)
 163                 seq_printf(m, ",time_offset=%d", opts->time_offset);
 164         return 0;
 165 }
 166
 167 static struct inode *exfat_alloc_inode(struct super_block *sb)
 168 {
 169         struct exfat_inode_info *ei;
 170
 171         ei = kmem_cache_alloc(exfat_inode_cachep, GFP_NOFS);
 172         if (!ei)
 173                 return NULL;
 174
 175         init_rwsem(&ei->truncate_lock);
 176         return &ei->vfs_inode;
 177 }
 178
 179 static void exfat_free_inode(struct inode *inode)
 180 {
 181         kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
 182 }
 183
 184 static const struct super_operations exfat_sops = {
 185         .alloc_inode    = exfat_alloc_inode,
 186         .free_inode     = exfat_free_inode,
 187         .write_inode    = exfat_write_inode,
 188         .evict_inode    = exfat_evict_inode,
 189         .put_super      = exfat_put_super,
 190         .sync_fs        = exfat_sync_fs,
 191         .statfs         = exfat_statfs,
 192         .show_options   = exfat_show_options,
 193 };
 194
 195 enum {
 196         Opt_uid,
 197         Opt_gid,
 198         Opt_umask,
 199         Opt_dmask,
 200         Opt_fmask,
 201         Opt_allow_utime,
 202         Opt_charset,
 203         Opt_errors,
 204         Opt_discard,
 205         Opt_time_offset,
 206 };
 207
 208 static const struct constant_table exfat_param_enums[] = {
 209         { "continue",           EXFAT_ERRORS_CONT },
 210         { "panic",              EXFAT_ERRORS_PANIC },
 211         { "remount-ro",         EXFAT_ERRORS_RO },
 212         {}
 213 };
 214
 215 static const struct fs_parameter_spec exfat_parameters[] = {
 216         fsparam_u32("uid",                      Opt_uid),
 217         fsparam_u32("gid",                      Opt_gid),
 218         fsparam_u32oct("umask",                 Opt_umask),
 219         fsparam_u32oct("dmask",                 Opt_dmask),
 220         fsparam_u32oct("fmask",                 Opt_fmask),
 221         fsparam_u32oct("allow_utime",           Opt_allow_utime),
 222         fsparam_string("iocharset",             Opt_charset),
 223         fsparam_enum("errors",                  Opt_errors, exfat_param_enums),
 224         fsparam_flag("discard",                 Opt_discard),
 225         fsparam_s32("time_offset",              Opt_time_offset),
 226         {}
 227 };
 228
 229 static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
 230 {
 231         struct exfat_sb_info *sbi = fc->s_fs_info;
 232         struct exfat_mount_options *opts = &sbi->options;
 233         struct fs_parse_result result;
 234         int opt;
 235
 236         opt = fs_parse(fc, exfat_parameters, param, &result);
 237         if (opt < 0)
 238                 return opt;
 239
 240         switch (opt) {
 241         case Opt_uid:
 242                 opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
 243                 break;
 244         case Opt_gid:
 245                 opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
 246                 break;
 247         case Opt_umask:
 248                 opts->fs_fmask = result.uint_32;
 249                 opts->fs_dmask = result.uint_32;
 250                 break;
 251         case Opt_dmask:
 252                 opts->fs_dmask = result.uint_32;
 253                 break;
 254         case Opt_fmask:
 255                 opts->fs_fmask = result.uint_32;
 256                 break;
 257         case Opt_allow_utime:
 258                 opts->allow_utime = result.uint_32 & 0022;
 259                 break;
 260         case Opt_charset:
 261                 exfat_free_iocharset(sbi);
 262                 opts->iocharset = kstrdup(param->string, GFP_KERNEL);
 263                 if (!opts->iocharset)
 264                         return -ENOMEM;
 265                 break;
 266         case Opt_errors:
 267                 opts->errors = result.uint_32;
 268                 break;
 269         case Opt_discard:
 270                 opts->discard = 1;
 271                 break;
 272         case Opt_time_offset:
 273                 /*
 274                  * Make the limit 24 just in case someone invents something
 275                  * unusual.
 276                  */
 277                 if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
 278                         return -EINVAL;
 279                 opts->time_offset = result.int_32;
 280                 break;
 281         default:
 282                 return -EINVAL;
 283         }
 284
 285         return 0;
 286 }
 287
 288 static void exfat_hash_init(struct super_block *sb)
 289 {
 290         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 291         int i;
 292
 293         spin_lock_init(&sbi->inode_hash_lock);
 294         for (i = 0; i < EXFAT_HASH_SIZE; i++)
 295                 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
 296 }
 297
 298 static int exfat_read_root(struct inode *inode)
 299 {
 300         struct super_block *sb = inode->i_sb;
 301         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 302         struct exfat_inode_info *ei = EXFAT_I(inode);
 303         struct exfat_chain cdir;
 304         int num_subdirs, num_clu = 0;
 305
 306         exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
 307         ei->entry = -1;
 308         ei->start_clu = sbi->root_dir;
 309         ei->flags = ALLOC_FAT_CHAIN;
 310         ei->type = TYPE_DIR;
 311         ei->version = 0;
 312         ei->rwoffset = 0;
 313         ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
 314         ei->hint_stat.eidx = 0;
 315         ei->hint_stat.clu = sbi->root_dir;
 316         ei->hint_femp.eidx = EXFAT_HINT_NONE;
 317
 318         exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
 319         if (exfat_count_num_clusters(sb, &cdir, &num_clu))
 320                 return -EIO;
 321         i_size_write(inode, num_clu << sbi->cluster_size_bits);
 322
 323         num_subdirs = exfat_count_dir_entries(sb, &cdir);
 324         if (num_subdirs < 0)
 325                 return -EIO;
 326         set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);
 327
 328         inode->i_uid = sbi->options.fs_uid;
 329         inode->i_gid = sbi->options.fs_gid;
 330         inode_inc_iversion(inode);
 331         inode->i_generation = 0;
 332         inode->i_mode = exfat_make_mode(sbi, ATTR_SUBDIR, 0777);
 333         inode->i_op = &exfat_dir_inode_operations;
 334         inode->i_fop = &exfat_dir_operations;
 335
 336         inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1))
 337                         & ~(sbi->cluster_size - 1)) >> inode->i_blkbits;
 338         EXFAT_I(inode)->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;
 339         EXFAT_I(inode)->i_size_aligned = i_size_read(inode);
 340         EXFAT_I(inode)->i_size_ondisk = i_size_read(inode);
 341
 342         exfat_save_attr(inode, ATTR_SUBDIR);
 343         inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
 344                 current_time(inode);
 345         exfat_truncate_atime(&inode->i_atime);
 346         exfat_cache_init_inode(inode);
 347         return 0;
 348 }
 349
 350 static struct pbr *exfat_read_pbr_with_logical_sector(struct super_block *sb)
 351 {
 352         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 353         struct pbr *p_pbr = (struct pbr *) (sbi->pbr_bh)->b_data;
 354         unsigned short logical_sect = 0;
 355
 356         logical_sect = 1 << p_pbr->bsx.f64.sect_size_bits;
 357
 358         if (!is_power_of_2(logical_sect) ||
 359             logical_sect < 512 || logical_sect > 4096) {
 360                 exfat_msg(sb, KERN_ERR, "bogus logical sector size %u",
 361                                 logical_sect);
 362                 return NULL;
 363         }
 364
 365         if (logical_sect < sb->s_blocksize) {
 366                 exfat_msg(sb, KERN_ERR,
 367                         "logical sector size too small for device (logical sector size = %u)",
 368                         logical_sect);
 369                 return NULL;
 370         }
 371
 372         if (logical_sect > sb->s_blocksize) {
 373                 brelse(sbi->pbr_bh);
 374                 sbi->pbr_bh = NULL;
 375
 376                 if (!sb_set_blocksize(sb, logical_sect)) {
 377                         exfat_msg(sb, KERN_ERR,
 378                                 "unable to set blocksize %u", logical_sect);
 379                         return NULL;
 380                 }
 381                 sbi->pbr_bh = sb_bread(sb, 0);
 382                 if (!sbi->pbr_bh) {
 383                         exfat_msg(sb, KERN_ERR,
 384                                 "unable to read boot sector (logical sector size = %lu)",
 385                                 sb->s_blocksize);
 386                         return NULL;
 387                 }
 388
 389                 p_pbr = (struct pbr *)sbi->pbr_bh->b_data;
 390         }
 391         return p_pbr;
 392 }
 393
 394 /* mount the file system volume */
 395 static int __exfat_fill_super(struct super_block *sb)
 396 {
 397         int ret;
 398         struct pbr *p_pbr;
 399         struct pbr64 *p_bpb;
 400         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 401
 402         /* set block size to read super block */
 403         sb_min_blocksize(sb, 512);
 404
 405         /* read boot sector */
 406         sbi->pbr_bh = sb_bread(sb, 0);
 407         if (!sbi->pbr_bh) {
 408                 exfat_msg(sb, KERN_ERR, "unable to read boot sector");
 409                 return -EIO;
 410         }
 411
 412         /* PRB is read */
 413         p_pbr = (struct pbr *)sbi->pbr_bh->b_data;
 414
 415         /* check the validity of PBR */
 416         if (le16_to_cpu((p_pbr->signature)) != PBR_SIGNATURE) {
 417                 exfat_msg(sb, KERN_ERR, "invalid boot record signature");
 418                 ret = -EINVAL;
 419                 goto free_bh;
 420         }
 421
 422
 423         /* check logical sector size */
 424         p_pbr = exfat_read_pbr_with_logical_sector(sb);
 425         if (!p_pbr) {
 426                 ret = -EIO;
 427                 goto free_bh;
 428         }
 429
 430         /*
 431          * res_zero field must be filled with zero to prevent mounting
 432          * from FAT volume.
 433          */
 434         if (memchr_inv(p_pbr->bpb.f64.res_zero, 0,
 435                         sizeof(p_pbr->bpb.f64.res_zero))) {
 436                 ret = -EINVAL;
 437                 goto free_bh;
 438         }
 439
 440         p_bpb = (struct pbr64 *)p_pbr;
 441         if (!p_bpb->bsx.num_fats) {
 442                 exfat_msg(sb, KERN_ERR, "bogus number of FAT structure");
 443                 ret = -EINVAL;
 444                 goto free_bh;
 445         }
 446
 447         sbi->sect_per_clus = 1 << p_bpb->bsx.sect_per_clus_bits;
 448         sbi->sect_per_clus_bits = p_bpb->bsx.sect_per_clus_bits;
 449         sbi->cluster_size_bits = sbi->sect_per_clus_bits + sb->s_blocksize_bits;
 450         sbi->cluster_size = 1 << sbi->cluster_size_bits;
 451         sbi->num_FAT_sectors = le32_to_cpu(p_bpb->bsx.fat_length);
 452         sbi->FAT1_start_sector = le32_to_cpu(p_bpb->bsx.fat_offset);
 453         sbi->FAT2_start_sector = p_bpb->bsx.num_fats == 1 ?
 454                 sbi->FAT1_start_sector :
 455                         sbi->FAT1_start_sector + sbi->num_FAT_sectors;
 456         sbi->data_start_sector = le32_to_cpu(p_bpb->bsx.clu_offset);
 457         sbi->num_sectors = le64_to_cpu(p_bpb->bsx.vol_length);
 458         /* because the cluster index starts with 2 */
 459         sbi->num_clusters = le32_to_cpu(p_bpb->bsx.clu_count) +
 460                 EXFAT_RESERVED_CLUSTERS;
 461
 462         sbi->root_dir = le32_to_cpu(p_bpb->bsx.root_cluster);
 463         sbi->dentries_per_clu = 1 <<
 464                 (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
 465
 466         sbi->vol_flag = le16_to_cpu(p_bpb->bsx.vol_flags);
 467         sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
 468         sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
 469
 470         if (le16_to_cpu(p_bpb->bsx.vol_flags) & VOL_DIRTY) {
 471                 sbi->vol_flag |= VOL_DIRTY;
 472                 exfat_msg(sb, KERN_WARNING,
 473                         "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
 474         }
 475
 476         /* exFAT file size is limited by a disk volume size */
 477         sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
 478                 sbi->cluster_size_bits;
 479
 480         ret = exfat_create_upcase_table(sb);
 481         if (ret) {
 482                 exfat_msg(sb, KERN_ERR, "failed to load upcase table");
 483                 goto free_bh;
 484         }
 485
 486         ret = exfat_load_bitmap(sb);
 487         if (ret) {
 488                 exfat_msg(sb, KERN_ERR, "failed to load alloc-bitmap");
 489                 goto free_upcase_table;
 490         }
 491
 492         ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
 493         if (ret) {
 494                 exfat_msg(sb, KERN_ERR, "failed to scan clusters");
 495                 goto free_alloc_bitmap;
 496         }
 497
 498         return 0;
 499
 500 free_alloc_bitmap:
 501         exfat_free_bitmap(sbi);
 502 free_upcase_table:
 503         exfat_free_upcase_table(sbi);
 504 free_bh:
 505         brelse(sbi->pbr_bh);
 506         return ret;
 507 }
 508
 509 static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
 510 {
 511         struct exfat_sb_info *sbi = sb->s_fs_info;
 512         struct exfat_mount_options *opts = &sbi->options;
 513         struct inode *root_inode;
 514         int err;
 515
 516         if (opts->allow_utime == (unsigned short)-1)
 517                 opts->allow_utime = ~opts->fs_dmask & 0022;
 518
 519         if (opts->discard) {
 520                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
 521
 522                 if (!blk_queue_discard(q)) {
 523                         exfat_msg(sb, KERN_WARNING,
 524                                 "mounting with \"discard\" option, but the device does not support discard");
 525                         opts->discard = 0;
 526                 }
 527         }
 528
 529         sb->s_flags |= SB_NODIRATIME;
 530         sb->s_magic = EXFAT_SUPER_MAGIC;
 531         sb->s_op = &exfat_sops;
 532
 533         sb->s_time_gran = 10 * NSEC_PER_MSEC;
 534         sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
 535         sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
 536
 537         err = __exfat_fill_super(sb);
 538         if (err) {
 539                 exfat_msg(sb, KERN_ERR, "failed to recognize exfat type");
 540                 goto check_nls_io;
 541         }
 542
 543         /* set up enough so that it can read an inode */
 544         exfat_hash_init(sb);
 545
 546         if (!strcmp(sbi->options.iocharset, "utf8"))
 547                 opts->utf8 = 1;
 548         else {
 549                 sbi->nls_io = load_nls(sbi->options.iocharset);
 550                 if (!sbi->nls_io) {
 551                         exfat_msg(sb, KERN_ERR, "IO charset %s not found",
 552                                         sbi->options.iocharset);
 553                         err = -EINVAL;
 554                         goto free_table;
 555                 }
 556         }
 557
 558         if (sbi->options.utf8)
 559                 sb->s_d_op = &exfat_utf8_dentry_ops;
 560         else
 561                 sb->s_d_op = &exfat_dentry_ops;
 562
 563         root_inode = new_inode(sb);
 564         if (!root_inode) {
 565                 exfat_msg(sb, KERN_ERR, "failed to allocate root inode.");
 566                 err = -ENOMEM;
 567                 goto free_table;
 568         }
 569
 570         root_inode->i_ino = EXFAT_ROOT_INO;
 571         inode_set_iversion(root_inode, 1);
 572         err = exfat_read_root(root_inode);
 573         if (err) {
 574                 exfat_msg(sb, KERN_ERR, "failed to initialize root inode.");
 575                 goto put_inode;
 576         }
 577
 578         exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
 579         insert_inode_hash(root_inode);
 580
 581         sb->s_root = d_make_root(root_inode);
 582         if (!sb->s_root) {
 583                 exfat_msg(sb, KERN_ERR, "failed to get the root dentry");
 584                 err = -ENOMEM;
 585                 goto put_inode;
 586         }
 587
 588         return 0;
 589
 590 put_inode:
 591         iput(root_inode);
 592         sb->s_root = NULL;
 593
 594 free_table:
 595         exfat_free_upcase_table(sbi);
 596         exfat_free_bitmap(sbi);
 597         brelse(sbi->pbr_bh);
 598
 599 check_nls_io:
 600         unload_nls(sbi->nls_io);
 601         exfat_free_iocharset(sbi);
 602         sb->s_fs_info = NULL;
 603         kfree(sbi);
 604         return err;
 605 }
 606
 607 static int exfat_get_tree(struct fs_context *fc)
 608 {
 609         return get_tree_bdev(fc, exfat_fill_super);
 610 }
 611
 612 static void exfat_free(struct fs_context *fc)
 613 {
 614         kfree(fc->s_fs_info);
 615 }
 616
 617 static const struct fs_context_operations exfat_context_ops = {
 618         .parse_param    = exfat_parse_param,
 619         .get_tree       = exfat_get_tree,
 620         .free           = exfat_free,
 621 };
 622
 623 static int exfat_init_fs_context(struct fs_context *fc)
 624 {
 625         struct exfat_sb_info *sbi;
 626
 627         sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
 628         if (!sbi)
 629                 return -ENOMEM;
 630
 631         mutex_init(&sbi->s_lock);
 632         ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
 633                         DEFAULT_RATELIMIT_BURST);
 634
 635         sbi->options.fs_uid = current_uid();
 636         sbi->options.fs_gid = current_gid();
 637         sbi->options.fs_fmask = current->fs->umask;
 638         sbi->options.fs_dmask = current->fs->umask;
 639         sbi->options.allow_utime = -1;
 640         sbi->options.iocharset = exfat_default_iocharset;
 641         sbi->options.errors = EXFAT_ERRORS_RO;
 642
 643         fc->s_fs_info = sbi;
 644         fc->ops = &exfat_context_ops;
 645         return 0;
 646 }
 647
 648 static struct file_system_type exfat_fs_type = {
 649         .owner                  = THIS_MODULE,
 650         .name                   = "exfat",
 651         .init_fs_context        = exfat_init_fs_context,
 652         .parameters             = exfat_parameters,
 653         .kill_sb                = kill_block_super,
 654         .fs_flags               = FS_REQUIRES_DEV,
 655 };
 656
 657 static void exfat_inode_init_once(void *foo)
 658 {
 659         struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;
 660
 661         INIT_HLIST_NODE(&ei->i_hash_fat);
 662         inode_init_once(&ei->vfs_inode);
 663 }
 664
 665 static int __init init_exfat_fs(void)
 666 {
 667         int err;
 668
 669         err = exfat_cache_init();
 670         if (err)
 671                 return err;
 672
 673         exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
 674                         sizeof(struct exfat_inode_info),
 675                         0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
 676                         exfat_inode_init_once);
 677         if (!exfat_inode_cachep) {
 678                 err = -ENOMEM;
 679                 goto shutdown_cache;
 680         }
 681
 682         err = register_filesystem(&exfat_fs_type);
 683         if (err)
 684                 goto destroy_cache;
 685
 686         return 0;
 687
 688 destroy_cache:
 689         kmem_cache_destroy(exfat_inode_cachep);
 690 shutdown_cache:
 691         exfat_cache_shutdown();
 692         return err;
 693 }
 694
 695 static void __exit exit_exfat_fs(void)
 696 {
 697         /*
 698          * Make sure all delayed rcu free inodes are flushed before we
 699          * destroy cache.
 700          */
 701         rcu_barrier();
 702         kmem_cache_destroy(exfat_inode_cachep);
 703         unregister_filesystem(&exfat_fs_type);
 704         exfat_cache_shutdown();
 705 }
 706
 707 module_init(init_exfat_fs);
 708 module_exit(exit_exfat_fs);
 709
 710 MODULE_ALIAS_FS("exfat");
 711 MODULE_LICENSE("GPL");
 712 MODULE_DESCRIPTION("exFAT filesystem support");
 713 MODULE_AUTHOR("Samsung Electronics Co., Ltd.");