// SPDX-License-Identifier: GPL-2.0-or-later
  /*
   *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
   */
  
  #include <linux/fs_context.h>
  #include <linux/fs_parser.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/time.h>
  #include <linux/mount.h>
  #include <linux/cred.h>
  #include <linux/statfs.h>
  #include <linux/seq_file.h>
  #include <linux/blkdev.h>
  #include <linux/fs_struct.h>
  #include <linux/iversion.h>
  #include <linux/nls.h>
  #include <linux/buffer_head.h>
  
  #include "exfat_raw.h"
  #include "exfat_fs.h"
  
  static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
  static struct kmem_cache *exfat_inode_cachep;
  
  static void exfat_free_iocharset(struct exfat_sb_info *sbi)
  {
  	if (sbi->options.iocharset != exfat_default_iocharset)
  		kfree(sbi->options.iocharset);
  }
  
  static void exfat_delayed_free(struct rcu_head *p)
  {
  	struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);
  
  	unload_nls(sbi->nls_io);
  	exfat_free_iocharset(sbi);
  	exfat_free_upcase_table(sbi);
  	kfree(sbi);
  }
  
  static void exfat_put_super(struct super_block *sb)
  {
  	struct exfat_sb_info *sbi = EXFAT_SB(sb);
  
  	mutex_lock(&sbi->s_lock);

  	exfat_free_bitmap(sbi);

  	brelse(sbi->boot_bh);

  	mutex_unlock(&sbi->s_lock);
  
  	call_rcu(&sbi->rcu, exfat_delayed_free);
  }
  
  static int exfat_sync_fs(struct super_block *sb, int wait)
  {
  	struct exfat_sb_info *sbi = EXFAT_SB(sb);
  	int err = 0;

  	if (!wait)
  		return 0;

  	/* If there are some dirty buffers in the bdev inode */
  	mutex_lock(&sbi->s_lock);

  	sync_blockdev(sb->s_bdev);

  	if (exfat_clear_volume_dirty(sb))

  		err = -EIO;

  	mutex_unlock(&sbi->s_lock);
  	return err;
  }
  
  static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
  {
  	struct super_block *sb = dentry->d_sb;
  	struct exfat_sb_info *sbi = EXFAT_SB(sb);
  	unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);
  
  	if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
  		mutex_lock(&sbi->s_lock);
  		if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
  			mutex_unlock(&sbi->s_lock);
  			return -EIO;
  		}
  		mutex_unlock(&sbi->s_lock);
  	}
  
  	buf->f_type = sb->s_magic;
  	buf->f_bsize = sbi->cluster_size;
  	buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
  	buf->f_bfree = buf->f_blocks - sbi->used_clusters;
  	buf->f_bavail = buf->f_bfree;

  	buf->f_fsid = u64_to_fsid(id);

  	/* Unicode utf16 255 characters */
  	buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
  	return 0;
  }

  static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)

  {
  	struct exfat_sb_info *sbi = EXFAT_SB(sb);

  	struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;

  	bool sync;

  	/* retain persistent-flags */
  	new_flags |= sbi->vol_flags_persistent;

  	/* flags are not changed */

  	if (sbi->vol_flags == new_flags)

  		return 0;

  	sbi->vol_flags = new_flags;

  
  	/* skip updating volume dirty flag,
  	 * if this volume has been mounted with read-only
  	 */
  	if (sb_rdonly(sb))
  		return 0;

  	p_boot->vol_flags = cpu_to_le16(new_flags);

  	if ((new_flags & VOLUME_DIRTY) && !buffer_dirty(sbi->boot_bh))

  		sync = true;
  	else
  		sync = false;

  	set_buffer_uptodate(sbi->boot_bh);
  	mark_buffer_dirty(sbi->boot_bh);

  
  	if (sync)

  		sync_dirty_buffer(sbi->boot_bh);

  	return 0;
  }

  int exfat_set_volume_dirty(struct super_block *sb)
  {
  	struct exfat_sb_info *sbi = EXFAT_SB(sb);
  
  	return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY);
  }
  
  int exfat_clear_volume_dirty(struct super_block *sb)
  {
  	struct exfat_sb_info *sbi = EXFAT_SB(sb);
  
  	return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY);
  }

  static int exfat_show_options(struct seq_file *m, struct dentry *root)
  {
  	struct super_block *sb = root->d_sb;
  	struct exfat_sb_info *sbi = EXFAT_SB(sb);
  	struct exfat_mount_options *opts = &sbi->options;
  
  	/* Show partition info */
  	if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
  		seq_printf(m, ",uid=%u",
  				from_kuid_munged(&init_user_ns, opts->fs_uid));
  	if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
  		seq_printf(m, ",gid=%u",
  				from_kgid_munged(&init_user_ns, opts->fs_gid));
  	seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
  	if (opts->allow_utime)
  		seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
  	if (opts->utf8)
  		seq_puts(m, ",iocharset=utf8");
  	else if (sbi->nls_io)
  		seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);

  	if (opts->errors == EXFAT_ERRORS_CONT)
  		seq_puts(m, ",errors=continue");
  	else if (opts->errors == EXFAT_ERRORS_PANIC)
  		seq_puts(m, ",errors=panic");
  	else
  		seq_puts(m, ",errors=remount-ro");
  	if (opts->discard)
  		seq_puts(m, ",discard");
  	if (opts->time_offset)
  		seq_printf(m, ",time_offset=%d", opts->time_offset);
  	return 0;
  }
  
  static struct inode *exfat_alloc_inode(struct super_block *sb)
  {
  	struct exfat_inode_info *ei;
  
  	ei = kmem_cache_alloc(exfat_inode_cachep, GFP_NOFS);
  	if (!ei)
  		return NULL;
  
  	init_rwsem(&ei->truncate_lock);
  	return &ei->vfs_inode;
  }
  
  static void exfat_free_inode(struct inode *inode)
  {
  	kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
  }
  
  static const struct super_operations exfat_sops = {
  	.alloc_inode	= exfat_alloc_inode,
  	.free_inode	= exfat_free_inode,
  	.write_inode	= exfat_write_inode,
  	.evict_inode	= exfat_evict_inode,
  	.put_super	= exfat_put_super,
  	.sync_fs	= exfat_sync_fs,
  	.statfs		= exfat_statfs,
  	.show_options	= exfat_show_options,
  };
  
  enum {
  	Opt_uid,
  	Opt_gid,
  	Opt_umask,
  	Opt_dmask,
  	Opt_fmask,
  	Opt_allow_utime,
  	Opt_charset,
  	Opt_errors,
  	Opt_discard,
  	Opt_time_offset,

  
  	/* Deprecated options */
  	Opt_utf8,
  	Opt_debug,
  	Opt_namecase,
  	Opt_codepage,

  };

  static const struct constant_table exfat_param_enums[] = {
  	{ "continue",		EXFAT_ERRORS_CONT },
  	{ "panic",		EXFAT_ERRORS_PANIC },
  	{ "remount-ro",		EXFAT_ERRORS_RO },
  	{}
  };
  
  static const struct fs_parameter_spec exfat_parameters[] = {

  	fsparam_u32("uid",			Opt_uid),
  	fsparam_u32("gid",			Opt_gid),
  	fsparam_u32oct("umask",			Opt_umask),
  	fsparam_u32oct("dmask",			Opt_dmask),
  	fsparam_u32oct("fmask",			Opt_fmask),
  	fsparam_u32oct("allow_utime",		Opt_allow_utime),
  	fsparam_string("iocharset",		Opt_charset),

  	fsparam_enum("errors",			Opt_errors, exfat_param_enums),

  	fsparam_flag("discard",			Opt_discard),
  	fsparam_s32("time_offset",		Opt_time_offset),

  	__fsparam(NULL, "utf8",			Opt_utf8, fs_param_deprecated,
  		  NULL),
  	__fsparam(NULL, "debug",		Opt_debug, fs_param_deprecated,
  		  NULL),
  	__fsparam(fs_param_is_u32, "namecase",	Opt_namecase,
  		  fs_param_deprecated, NULL),
  	__fsparam(fs_param_is_u32, "codepage",	Opt_codepage,
  		  fs_param_deprecated, NULL),

  	{}
  };

  static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
  {
  	struct exfat_sb_info *sbi = fc->s_fs_info;
  	struct exfat_mount_options *opts = &sbi->options;
  	struct fs_parse_result result;
  	int opt;

  	opt = fs_parse(fc, exfat_parameters, param, &result);

  	if (opt < 0)
  		return opt;
  
  	switch (opt) {
  	case Opt_uid:
  		opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
  		break;
  	case Opt_gid:
  		opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
  		break;
  	case Opt_umask:
  		opts->fs_fmask = result.uint_32;
  		opts->fs_dmask = result.uint_32;
  		break;
  	case Opt_dmask:
  		opts->fs_dmask = result.uint_32;
  		break;
  	case Opt_fmask:
  		opts->fs_fmask = result.uint_32;
  		break;
  	case Opt_allow_utime:
  		opts->allow_utime = result.uint_32 & 0022;
  		break;
  	case Opt_charset:
  		exfat_free_iocharset(sbi);

  		opts->iocharset = param->string;
  		param->string = NULL;

  		break;
  	case Opt_errors:
  		opts->errors = result.uint_32;
  		break;
  	case Opt_discard:
  		opts->discard = 1;
  		break;
  	case Opt_time_offset:
  		/*
  		 * Make the limit 24 just in case someone invents something
  		 * unusual.
  		 */
  		if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
  			return -EINVAL;
  		opts->time_offset = result.int_32;
  		break;

  	case Opt_utf8:
  	case Opt_debug:
  	case Opt_namecase:
  	case Opt_codepage:
  		break;

  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static void exfat_hash_init(struct super_block *sb)
  {
  	struct exfat_sb_info *sbi = EXFAT_SB(sb);
  	int i;
  
  	spin_lock_init(&sbi->inode_hash_lock);
  	for (i = 0; i < EXFAT_HASH_SIZE; i++)
  		INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
  }
  
  static int exfat_read_root(struct inode *inode)
  {
  	struct super_block *sb = inode->i_sb;
  	struct exfat_sb_info *sbi = EXFAT_SB(sb);
  	struct exfat_inode_info *ei = EXFAT_I(inode);
  	struct exfat_chain cdir;
  	int num_subdirs, num_clu = 0;
  
  	exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
  	ei->entry = -1;
  	ei->start_clu = sbi->root_dir;
  	ei->flags = ALLOC_FAT_CHAIN;
  	ei->type = TYPE_DIR;
  	ei->version = 0;

  	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
  	ei->hint_stat.eidx = 0;
  	ei->hint_stat.clu = sbi->root_dir;
  	ei->hint_femp.eidx = EXFAT_HINT_NONE;
  
  	exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
  	if (exfat_count_num_clusters(sb, &cdir, &num_clu))
  		return -EIO;
  	i_size_write(inode, num_clu << sbi->cluster_size_bits);
  
  	num_subdirs = exfat_count_dir_entries(sb, &cdir);
  	if (num_subdirs < 0)
  		return -EIO;
  	set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);
  
  	inode->i_uid = sbi->options.fs_uid;
  	inode->i_gid = sbi->options.fs_gid;
  	inode_inc_iversion(inode);
  	inode->i_generation = 0;
  	inode->i_mode = exfat_make_mode(sbi, ATTR_SUBDIR, 0777);
  	inode->i_op = &exfat_dir_inode_operations;
  	inode->i_fop = &exfat_dir_operations;
  
  	inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1))
  			& ~(sbi->cluster_size - 1)) >> inode->i_blkbits;
  	EXFAT_I(inode)->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;
  	EXFAT_I(inode)->i_size_aligned = i_size_read(inode);
  	EXFAT_I(inode)->i_size_ondisk = i_size_read(inode);
  
  	exfat_save_attr(inode, ATTR_SUBDIR);
  	inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
  		current_time(inode);

  	exfat_truncate_atime(&inode->i_atime);

  	return 0;
  }

  static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)

  {

  	struct exfat_sb_info *sbi = EXFAT_SB(sb);

  
  	if (!is_power_of_2(logical_sect) ||
  	    logical_sect < 512 || logical_sect > 4096) {

  		exfat_err(sb, "bogus logical sector size %u", logical_sect);

  		return -EIO;

  	}
  
  	if (logical_sect < sb->s_blocksize) {

  		exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",
  			  logical_sect);

  		return -EIO;

  	}
  
  	if (logical_sect > sb->s_blocksize) {

  		brelse(sbi->boot_bh);
  		sbi->boot_bh = NULL;

  
  		if (!sb_set_blocksize(sb, logical_sect)) {

  			exfat_err(sb, "unable to set blocksize %u",
  				  logical_sect);

  			return -EIO;

  		}

  		sbi->boot_bh = sb_bread(sb, 0);
  		if (!sbi->boot_bh) {

  			exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
  				  sb->s_blocksize);

  			return -EIO;

  		}

  	}

  	return 0;

  }

  static int exfat_read_boot_sector(struct super_block *sb)

  {

  	struct boot_sector *p_boot;

  	struct exfat_sb_info *sbi = EXFAT_SB(sb);
  
  	/* set block size to read super block */
  	sb_min_blocksize(sb, 512);
  
  	/* read boot sector */

  	sbi->boot_bh = sb_bread(sb, 0);
  	if (!sbi->boot_bh) {

  		exfat_err(sb, "unable to read boot sector");

  		return -EIO;
  	}

  	p_boot = (struct boot_sector *)sbi->boot_bh->b_data;

  	/* check the validity of BOOT */
  	if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {

  		exfat_err(sb, "invalid boot record signature");

  		return -EINVAL;

  	}

  	if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) {
  		exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */
  		return -EINVAL;

  	}
  
  	/*

  	 * must_be_zero field must be filled with zero to prevent mounting

  	 * from FAT volume.
  	 */

  	if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))
  		return -EINVAL;

  	if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {

  		exfat_err(sb, "bogus number of FAT structure");

  		return -EINVAL;

  	}

  	sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
  	sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;

  	sbi->cluster_size_bits = p_boot->sect_per_clus_bits +
  		p_boot->sect_size_bits;

  	sbi->cluster_size = 1 << sbi->cluster_size_bits;

  	sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
  	sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);

  	sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);
  	if (p_boot->num_fats == 2)
  		sbi->FAT2_start_sector += sbi->num_FAT_sectors;

  	sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
  	sbi->num_sectors = le64_to_cpu(p_boot->vol_length);

  	/* because the cluster index starts with 2 */

  	sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +

  		EXFAT_RESERVED_CLUSTERS;

  	sbi->root_dir = le32_to_cpu(p_boot->root_cluster);

  	sbi->dentries_per_clu = 1 <<
  		(sbi->cluster_size_bits - DENTRY_SIZE_BITS);

  	sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);
  	sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);

  	sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
  	sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;

  	/* check consistencies */
  	if (sbi->num_FAT_sectors << p_boot->sect_size_bits <
  	    sbi->num_clusters * 4) {
  		exfat_err(sb, "bogus fat length");
  		return -EINVAL;
  	}
  	if (sbi->data_start_sector <
  	    sbi->FAT1_start_sector + sbi->num_FAT_sectors * p_boot->num_fats) {
  		exfat_err(sb, "bogus data start sector");
  		return -EINVAL;

  	}

  	if (sbi->vol_flags & VOLUME_DIRTY)

  		exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");

  	if (sbi->vol_flags & MEDIA_FAILURE)

  		exfat_warn(sb, "Medium has reported failures. Some data may be lost.");

  
  	/* exFAT file size is limited by a disk volume size */
  	sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
  		sbi->cluster_size_bits;

  	/* check logical sector size */
  	if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
  		return -EIO;
  
  	return 0;
  }

  static int exfat_verify_boot_region(struct super_block *sb)
  {
  	struct buffer_head *bh = NULL;
  	u32 chksum = 0;
  	__le32 *p_sig, *p_chksum;
  	int sn, i;
  
  	/* read boot sector sub-regions */
  	for (sn = 0; sn < 11; sn++) {
  		bh = sb_bread(sb, sn);
  		if (!bh)
  			return -EIO;
  
  		if (sn != 0 && sn <= 8) {
  			/* extended boot sector sub-regions */
  			p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4];
  			if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)
  				exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",
  					   sn, le32_to_cpu(*p_sig));
  		}
  
  		chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
  			chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
  		brelse(bh);
  	}
  
  	/* boot checksum sub-regions */
  	bh = sb_bread(sb, sn);
  	if (!bh)
  		return -EIO;
  
  	for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
  		p_chksum = (__le32 *)&bh->b_data[i];
  		if (le32_to_cpu(*p_chksum) != chksum) {
  			exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",
  				  le32_to_cpu(*p_chksum), chksum);
  			brelse(bh);
  			return -EINVAL;
  		}
  	}
  	brelse(bh);
  	return 0;
  }

  /* mount the file system volume */
  static int __exfat_fill_super(struct super_block *sb)
  {
  	int ret;
  	struct exfat_sb_info *sbi = EXFAT_SB(sb);
  
  	ret = exfat_read_boot_sector(sb);
  	if (ret) {
  		exfat_err(sb, "failed to read boot sector");
  		goto free_bh;

  	}
  
  	ret = exfat_verify_boot_region(sb);
  	if (ret) {
  		exfat_err(sb, "invalid boot region");
  		goto free_bh;

  	}

  	ret = exfat_create_upcase_table(sb);
  	if (ret) {

  		exfat_err(sb, "failed to load upcase table");

  		goto free_bh;
  	}
  
  	ret = exfat_load_bitmap(sb);
  	if (ret) {

  		exfat_err(sb, "failed to load alloc-bitmap");

  		goto free_upcase_table;
  	}
  
  	ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
  	if (ret) {

  		exfat_err(sb, "failed to scan clusters");

  		goto free_alloc_bitmap;
  	}
  
  	return 0;
  
  free_alloc_bitmap:
  	exfat_free_bitmap(sbi);
  free_upcase_table:
  	exfat_free_upcase_table(sbi);
  free_bh:

  	brelse(sbi->boot_bh);

  	return ret;
  }
  
  static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
  {
  	struct exfat_sb_info *sbi = sb->s_fs_info;
  	struct exfat_mount_options *opts = &sbi->options;
  	struct inode *root_inode;
  	int err;
  
  	if (opts->allow_utime == (unsigned short)-1)
  		opts->allow_utime = ~opts->fs_dmask & 0022;
  
  	if (opts->discard) {
  		struct request_queue *q = bdev_get_queue(sb->s_bdev);

  		if (!blk_queue_discard(q)) {

  			exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard");

  			opts->discard = 0;
  		}

  	}
  
  	sb->s_flags |= SB_NODIRATIME;
  	sb->s_magic = EXFAT_SUPER_MAGIC;
  	sb->s_op = &exfat_sops;

  	sb->s_time_gran = 10 * NSEC_PER_MSEC;

  	sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
  	sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
  
  	err = __exfat_fill_super(sb);
  	if (err) {

  		exfat_err(sb, "failed to recognize exfat type");

  		goto check_nls_io;
  	}
  
  	/* set up enough so that it can read an inode */
  	exfat_hash_init(sb);
  
  	if (!strcmp(sbi->options.iocharset, "utf8"))
  		opts->utf8 = 1;
  	else {
  		sbi->nls_io = load_nls(sbi->options.iocharset);
  		if (!sbi->nls_io) {

  			exfat_err(sb, "IO charset %s not found",
  				  sbi->options.iocharset);

  			err = -EINVAL;
  			goto free_table;
  		}
  	}
  
  	if (sbi->options.utf8)
  		sb->s_d_op = &exfat_utf8_dentry_ops;
  	else
  		sb->s_d_op = &exfat_dentry_ops;
  
  	root_inode = new_inode(sb);
  	if (!root_inode) {

  		exfat_err(sb, "failed to allocate root inode");

  		err = -ENOMEM;
  		goto free_table;
  	}
  
  	root_inode->i_ino = EXFAT_ROOT_INO;
  	inode_set_iversion(root_inode, 1);
  	err = exfat_read_root(root_inode);
  	if (err) {

  		exfat_err(sb, "failed to initialize root inode");

  		goto put_inode;
  	}
  
  	exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
  	insert_inode_hash(root_inode);
  
  	sb->s_root = d_make_root(root_inode);
  	if (!sb->s_root) {

  		exfat_err(sb, "failed to get the root dentry");

  		err = -ENOMEM;
  		goto put_inode;
  	}
  
  	return 0;
  
  put_inode:
  	iput(root_inode);
  	sb->s_root = NULL;
  
  free_table:
  	exfat_free_upcase_table(sbi);
  	exfat_free_bitmap(sbi);

  	brelse(sbi->boot_bh);

  
  check_nls_io:
  	unload_nls(sbi->nls_io);
  	exfat_free_iocharset(sbi);
  	sb->s_fs_info = NULL;
  	kfree(sbi);
  	return err;
  }
  
  static int exfat_get_tree(struct fs_context *fc)
  {
  	return get_tree_bdev(fc, exfat_fill_super);
  }
  
  static void exfat_free(struct fs_context *fc)
  {

  	struct exfat_sb_info *sbi = fc->s_fs_info;
  
  	if (sbi) {
  		exfat_free_iocharset(sbi);
  		kfree(sbi);
  	}

  }

  static int exfat_reconfigure(struct fs_context *fc)
  {
  	fc->sb_flags |= SB_NODIRATIME;
  
  	/* volume flag will be updated in exfat_sync_fs */
  	sync_filesystem(fc->root->d_sb);
  	return 0;
  }

  static const struct fs_context_operations exfat_context_ops = {
  	.parse_param	= exfat_parse_param,
  	.get_tree	= exfat_get_tree,
  	.free		= exfat_free,

  	.reconfigure	= exfat_reconfigure,

  };
  
  static int exfat_init_fs_context(struct fs_context *fc)
  {
  	struct exfat_sb_info *sbi;
  
  	sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
  	if (!sbi)
  		return -ENOMEM;
  
  	mutex_init(&sbi->s_lock);
  	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
  			DEFAULT_RATELIMIT_BURST);
  
  	sbi->options.fs_uid = current_uid();
  	sbi->options.fs_gid = current_gid();
  	sbi->options.fs_fmask = current->fs->umask;
  	sbi->options.fs_dmask = current->fs->umask;
  	sbi->options.allow_utime = -1;
  	sbi->options.iocharset = exfat_default_iocharset;
  	sbi->options.errors = EXFAT_ERRORS_RO;
  
  	fc->s_fs_info = sbi;
  	fc->ops = &exfat_context_ops;
  	return 0;
  }
  
  static struct file_system_type exfat_fs_type = {
  	.owner			= THIS_MODULE,
  	.name			= "exfat",
  	.init_fs_context	= exfat_init_fs_context,

  	.parameters		= exfat_parameters,

  	.kill_sb		= kill_block_super,
  	.fs_flags		= FS_REQUIRES_DEV,
  };
  
  static void exfat_inode_init_once(void *foo)
  {
  	struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;

  	spin_lock_init(&ei->cache_lru_lock);
  	ei->nr_caches = 0;
  	ei->cache_valid_id = EXFAT_CACHE_VALID + 1;
  	INIT_LIST_HEAD(&ei->cache_lru);

  	INIT_HLIST_NODE(&ei->i_hash_fat);
  	inode_init_once(&ei->vfs_inode);
  }
  
  static int __init init_exfat_fs(void)
  {
  	int err;
  
  	err = exfat_cache_init();
  	if (err)
  		return err;
  
  	exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
  			sizeof(struct exfat_inode_info),
  			0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
  			exfat_inode_init_once);
  	if (!exfat_inode_cachep) {
  		err = -ENOMEM;
  		goto shutdown_cache;
  	}
  
  	err = register_filesystem(&exfat_fs_type);
  	if (err)
  		goto destroy_cache;
  
  	return 0;
  
  destroy_cache:
  	kmem_cache_destroy(exfat_inode_cachep);
  shutdown_cache:
  	exfat_cache_shutdown();
  	return err;
  }
  
  static void __exit exit_exfat_fs(void)
  {
  	/*
  	 * Make sure all delayed rcu free inodes are flushed before we
  	 * destroy cache.
  	 */
  	rcu_barrier();
  	kmem_cache_destroy(exfat_inode_cachep);
  	unregister_filesystem(&exfat_fs_type);
  	exfat_cache_shutdown();
  }
  
  module_init(init_exfat_fs);
  module_exit(exit_exfat_fs);

  MODULE_ALIAS_FS("exfat");

  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("exFAT filesystem support");
  MODULE_AUTHOR("Samsung Electronics Co., Ltd.");