[thirdparty/linux.git] / fs / exfat / super.c

// 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);
	if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state))
		sync_blockdev(sb->s_bdev);
	exfat_set_vol_flags(sb, VOL_CLEAN);
	exfat_free_bitmap(sbi);
	brelse(sbi->pbr_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 there are some dirty buffers in the bdev inode */
	mutex_lock(&sbi->s_lock);
	if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state)) {
		sync_blockdev(sb->s_bdev);
		if (exfat_set_vol_flags(sb, VOL_CLEAN))
			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.val[0] = (unsigned int)id;
	buf->f_fsid.val[1] = (unsigned int)(id >> 32);
	/* Unicode utf16 255 characters */
	buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
	return 0;
}

int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flag)
{
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	struct pbr64 *bpb = (struct pbr64 *)sbi->pbr_bh->b_data;
	bool sync = 0;

	/* flags are not changed */
	if (sbi->vol_flag == new_flag)
		return 0;

	sbi->vol_flag = new_flag;

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

	bpb->bsx.vol_flags = cpu_to_le16(new_flag);

	if (new_flag == VOL_DIRTY && !buffer_dirty(sbi->pbr_bh))
		sync = true;
	else
		sync = false;

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

	if (sync)
		sync_dirty_buffer(sbi->pbr_bh);
	return 0;
}

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 = kstrdup(param->string, GFP_KERNEL);
		if (!opts->iocharset)
			return -ENOMEM;
		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->rwoffset = 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);
	exfat_cache_init_inode(inode);
	return 0;
}

static struct pbr *exfat_read_pbr_with_logical_sector(struct super_block *sb)
{
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	struct pbr *p_pbr = (struct pbr *) (sbi->pbr_bh)->b_data;
	unsigned short logical_sect = 0;

	logical_sect = 1 << p_pbr->bsx.f64.sect_size_bits;

	if (!is_power_of_2(logical_sect) ||
	    logical_sect < 512 || logical_sect > 4096) {
		exfat_msg(sb, KERN_ERR, "bogus logical sector size %u",
				logical_sect);
		return NULL;
	}

	if (logical_sect < sb->s_blocksize) {
		exfat_msg(sb, KERN_ERR,
			"logical sector size too small for device (logical sector size = %u)",
			logical_sect);
		return NULL;
	}

	if (logical_sect > sb->s_blocksize) {
		brelse(sbi->pbr_bh);
		sbi->pbr_bh = NULL;

		if (!sb_set_blocksize(sb, logical_sect)) {
			exfat_msg(sb, KERN_ERR,
				"unable to set blocksize %u", logical_sect);
			return NULL;
		}
		sbi->pbr_bh = sb_bread(sb, 0);
		if (!sbi->pbr_bh) {
			exfat_msg(sb, KERN_ERR,
				"unable to read boot sector (logical sector size = %lu)",
				sb->s_blocksize);
			return NULL;
		}

		p_pbr = (struct pbr *)sbi->pbr_bh->b_data;
	}
	return p_pbr;
}

/* mount the file system volume */
static int __exfat_fill_super(struct super_block *sb)
{
	int ret;
	struct pbr *p_pbr;
	struct pbr64 *p_bpb;
	struct exfat_sb_info *sbi = EXFAT_SB(sb);

	/* set block size to read super block */
	sb_min_blocksize(sb, 512);

	/* read boot sector */
	sbi->pbr_bh = sb_bread(sb, 0);
	if (!sbi->pbr_bh) {
		exfat_msg(sb, KERN_ERR, "unable to read boot sector");
		return -EIO;
	}

	/* PRB is read */
	p_pbr = (struct pbr *)sbi->pbr_bh->b_data;

	/* check the validity of PBR */
	if (le16_to_cpu((p_pbr->signature)) != PBR_SIGNATURE) {
		exfat_msg(sb, KERN_ERR, "invalid boot record signature");
		ret = -EINVAL;
		goto free_bh;
	}


	/* check logical sector size */
	p_pbr = exfat_read_pbr_with_logical_sector(sb);
	if (!p_pbr) {
		ret = -EIO;
		goto free_bh;
	}

	/*
	 * res_zero field must be filled with zero to prevent mounting
	 * from FAT volume.
	 */
	if (memchr_inv(p_pbr->bpb.f64.res_zero, 0,
			sizeof(p_pbr->bpb.f64.res_zero))) {
		ret = -EINVAL;
		goto free_bh;
	}

	p_bpb = (struct pbr64 *)p_pbr;
	if (!p_bpb->bsx.num_fats) {
		exfat_msg(sb, KERN_ERR, "bogus number of FAT structure");
		ret = -EINVAL;
		goto free_bh;
	}

	sbi->sect_per_clus = 1 << p_bpb->bsx.sect_per_clus_bits;
	sbi->sect_per_clus_bits = p_bpb->bsx.sect_per_clus_bits;
	sbi->cluster_size_bits = sbi->sect_per_clus_bits + sb->s_blocksize_bits;
	sbi->cluster_size = 1 << sbi->cluster_size_bits;
	sbi->num_FAT_sectors = le32_to_cpu(p_bpb->bsx.fat_length);
	sbi->FAT1_start_sector = le32_to_cpu(p_bpb->bsx.fat_offset);
	sbi->FAT2_start_sector = p_bpb->bsx.num_fats == 1 ?
		sbi->FAT1_start_sector :
			sbi->FAT1_start_sector + sbi->num_FAT_sectors;
	sbi->data_start_sector = le32_to_cpu(p_bpb->bsx.clu_offset);
	sbi->num_sectors = le64_to_cpu(p_bpb->bsx.vol_length);
	/* because the cluster index starts with 2 */
	sbi->num_clusters = le32_to_cpu(p_bpb->bsx.clu_count) +
		EXFAT_RESERVED_CLUSTERS;

	sbi->root_dir = le32_to_cpu(p_bpb->bsx.root_cluster);
	sbi->dentries_per_clu = 1 <<
		(sbi->cluster_size_bits - DENTRY_SIZE_BITS);

	sbi->vol_flag = le16_to_cpu(p_bpb->bsx.vol_flags);
	sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
	sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;

	if (le16_to_cpu(p_bpb->bsx.vol_flags) & VOL_DIRTY) {
		sbi->vol_flag |= VOL_DIRTY;
		exfat_msg(sb, KERN_WARNING,
			"Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
	}

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

	ret = exfat_create_upcase_table(sb);
	if (ret) {
		exfat_msg(sb, KERN_ERR, "failed to load upcase table");
		goto free_bh;
	}

	ret = exfat_load_bitmap(sb);
	if (ret) {
		exfat_msg(sb, KERN_ERR, "failed to load alloc-bitmap");
		goto free_upcase_table;
	}

	ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
	if (ret) {
		exfat_msg(sb, KERN_ERR, "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->pbr_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_msg(sb, KERN_WARNING,
				"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_msg(sb, KERN_ERR, "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_msg(sb, KERN_ERR, "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_msg(sb, KERN_ERR, "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_msg(sb, KERN_ERR, "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_msg(sb, KERN_ERR, "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->pbr_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)
{
	kfree(fc->s_fs_info);
}

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

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;

	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.");
Commit	Line	Data
719c1e18 NJ	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);
b0516833	52	brelse(sbi->pbr_bh);
719c1e18 NJ	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);
b0516833	104	struct pbr64 bpb = (struct pbr64 )sbi->pbr_bh->b_data;
719c1e18 NJ	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
719c1e18 NJ	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);
719c1e18 NJ	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,
907fa893 NJ	206
	207	/* Deprecated options */
	208	Opt_utf8,
	209	Opt_debug,
	210	Opt_namecase,
	211	Opt_codepage,
719c1e18 NJ	212	};
719c1e18 NJ	213
9acd0d53 VK	214	static const struct constant_table exfat_param_enums[] = {
	215	{ "continue", EXFAT_ERRORS_CONT },
	216	{ "panic", EXFAT_ERRORS_PANIC },
	217	{ "remount-ro", EXFAT_ERRORS_RO },
	218	{}
	219	};
	220
	221	static const struct fs_parameter_spec exfat_parameters[] = {
719c1e18 NJ	222	fsparam_u32("uid", Opt_uid),
	223	fsparam_u32("gid", Opt_gid),
	224	fsparam_u32oct("umask", Opt_umask),
	225	fsparam_u32oct("dmask", Opt_dmask),
	226	fsparam_u32oct("fmask", Opt_fmask),
	227	fsparam_u32oct("allow_utime", Opt_allow_utime),
	228	fsparam_string("iocharset", Opt_charset),
9acd0d53	229	fsparam_enum("errors", Opt_errors, exfat_param_enums),
719c1e18 NJ	230	fsparam_flag("discard", Opt_discard),
719c1e18 NJ	231	fsparam_s32("time_offset", Opt_time_offset),
907fa893 NJ	232	__fsparam(NULL, "utf8", Opt_utf8, fs_param_deprecated,
	233	NULL),
	234	__fsparam(NULL, "debug", Opt_debug, fs_param_deprecated,
	235	NULL),
	236	__fsparam(fs_param_is_u32, "namecase", Opt_namecase,
	237	fs_param_deprecated, NULL),
	238	__fsparam(fs_param_is_u32, "codepage", Opt_codepage,
	239	fs_param_deprecated, NULL),
719c1e18 NJ	240	{}
	241	};
	242
719c1e18 NJ	243	static int exfat_parse_param(struct fs_context fc, struct fs_parameter param)
	244	{
	245	struct exfat_sb_info *sbi = fc->s_fs_info;
	246	struct exfat_mount_options *opts = &sbi->options;
	247	struct fs_parse_result result;
	248	int opt;
	249
9acd0d53	250	opt = fs_parse(fc, exfat_parameters, param, &result);
719c1e18 NJ	251	if (opt < 0)
	252	return opt;
	253
	254	switch (opt) {
	255	case Opt_uid:
	256	opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
	257	break;
	258	case Opt_gid:
	259	opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
	260	break;
	261	case Opt_umask:
	262	opts->fs_fmask = result.uint_32;
	263	opts->fs_dmask = result.uint_32;
	264	break;
	265	case Opt_dmask:
	266	opts->fs_dmask = result.uint_32;
	267	break;
	268	case Opt_fmask:
	269	opts->fs_fmask = result.uint_32;
	270	break;
	271	case Opt_allow_utime:
	272	opts->allow_utime = result.uint_32 & 0022;
	273	break;
	274	case Opt_charset:
	275	exfat_free_iocharset(sbi);
	276	opts->iocharset = kstrdup(param->string, GFP_KERNEL);
	277	if (!opts->iocharset)
	278	return -ENOMEM;
	279	break;
	280	case Opt_errors:
	281	opts->errors = result.uint_32;
	282	break;
	283	case Opt_discard:
	284	opts->discard = 1;
	285	break;
	286	case Opt_time_offset:
	287	/*
	288	* Make the limit 24 just in case someone invents something
	289	* unusual.
	290	*/
	291	if (result.int_32 < -24 * 60 \|\| result.int_32 > 24 * 60)
	292	return -EINVAL;
	293	opts->time_offset = result.int_32;
	294	break;
907fa893 NJ	295	case Opt_utf8:
	296	case Opt_debug:
	297	case Opt_namecase:
	298	case Opt_codepage:
	299	break;
719c1e18 NJ	300	default:
	301	return -EINVAL;
	302	}
	303
	304	return 0;
	305	}
	306
	307	static void exfat_hash_init(struct super_block *sb)
	308	{
	309	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	310	int i;
	311
	312	spin_lock_init(&sbi->inode_hash_lock);
	313	for (i = 0; i < EXFAT_HASH_SIZE; i++)
	314	INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
	315	}
	316
	317	static int exfat_read_root(struct inode *inode)
	318	{
	319	struct super_block *sb = inode->i_sb;
	320	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	321	struct exfat_inode_info *ei = EXFAT_I(inode);
	322	struct exfat_chain cdir;
	323	int num_subdirs, num_clu = 0;
	324
	325	exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
	326	ei->entry = -1;
	327	ei->start_clu = sbi->root_dir;
	328	ei->flags = ALLOC_FAT_CHAIN;
	329	ei->type = TYPE_DIR;
	330	ei->version = 0;
	331	ei->rwoffset = 0;
	332	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
	333	ei->hint_stat.eidx = 0;
	334	ei->hint_stat.clu = sbi->root_dir;
	335	ei->hint_femp.eidx = EXFAT_HINT_NONE;
	336
	337	exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
	338	if (exfat_count_num_clusters(sb, &cdir, &num_clu))
	339	return -EIO;
	340	i_size_write(inode, num_clu << sbi->cluster_size_bits);
	341
	342	num_subdirs = exfat_count_dir_entries(sb, &cdir);
	343	if (num_subdirs < 0)
	344	return -EIO;
	345	set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);
	346
	347	inode->i_uid = sbi->options.fs_uid;
	348	inode->i_gid = sbi->options.fs_gid;
	349	inode_inc_iversion(inode);
	350	inode->i_generation = 0;
	351	inode->i_mode = exfat_make_mode(sbi, ATTR_SUBDIR, 0777);
	352	inode->i_op = &exfat_dir_inode_operations;
	353	inode->i_fop = &exfat_dir_operations;
	354
	355	inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1))
	356	& ~(sbi->cluster_size - 1)) >> inode->i_blkbits;
	357	EXFAT_I(inode)->i_pos = ((loff_t)sbi->root_dir << 32) \| 0xffffffff;
	358	EXFAT_I(inode)->i_size_aligned = i_size_read(inode);
	359	EXFAT_I(inode)->i_size_ondisk = i_size_read(inode);
	360
	361	exfat_save_attr(inode, ATTR_SUBDIR);
	362	inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
	363	current_time(inode);
81df1ad4	364	exfat_truncate_atime(&inode->i_atime);
719c1e18 NJ	365	exfat_cache_init_inode(inode);
	366	return 0;
	367	}
	368
b0516833	369	static struct pbr exfat_read_pbr_with_logical_sector(struct super_block sb)
719c1e18	370	{
b0516833 TK	371	struct exfat_sb_info *sbi = EXFAT_SB(sb);
b0516833 TK	372	struct pbr p_pbr = (struct pbr ) (sbi->pbr_bh)->b_data;
719c1e18 NJ	373	unsigned short logical_sect = 0;
	374
	375	logical_sect = 1 << p_pbr->bsx.f64.sect_size_bits;
	376
	377	if (!is_power_of_2(logical_sect) \|\|
	378	logical_sect < 512 \|\| logical_sect > 4096) {
	379	exfat_msg(sb, KERN_ERR, "bogus logical sector size %u",
	380	logical_sect);
	381	return NULL;
	382	}
	383
	384	if (logical_sect < sb->s_blocksize) {
	385	exfat_msg(sb, KERN_ERR,
	386	"logical sector size too small for device (logical sector size = %u)",
	387	logical_sect);
	388	return NULL;
	389	}
	390
	391	if (logical_sect > sb->s_blocksize) {
b0516833 TK	392	brelse(sbi->pbr_bh);
b0516833 TK	393	sbi->pbr_bh = NULL;
719c1e18 NJ	394
	395	if (!sb_set_blocksize(sb, logical_sect)) {
	396	exfat_msg(sb, KERN_ERR,
	397	"unable to set blocksize %u", logical_sect);
	398	return NULL;
	399	}
b0516833 TK	400	sbi->pbr_bh = sb_bread(sb, 0);
b0516833 TK	401	if (!sbi->pbr_bh) {
719c1e18 NJ	402	exfat_msg(sb, KERN_ERR,
	403	"unable to read boot sector (logical sector size = %lu)",
	404	sb->s_blocksize);
	405	return NULL;
	406	}
	407
b0516833	408	p_pbr = (struct pbr *)sbi->pbr_bh->b_data;
719c1e18 NJ	409	}
	410	return p_pbr;
	411	}
	412
	413	/* mount the file system volume */
	414	static int __exfat_fill_super(struct super_block *sb)
	415	{
	416	int ret;
	417	struct pbr *p_pbr;
	418	struct pbr64 *p_bpb;
719c1e18 NJ	419	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	420
	421	/* set block size to read super block */
	422	sb_min_blocksize(sb, 512);
	423
	424	/* read boot sector */
b0516833 TK	425	sbi->pbr_bh = sb_bread(sb, 0);
b0516833 TK	426	if (!sbi->pbr_bh) {
719c1e18 NJ	427	exfat_msg(sb, KERN_ERR, "unable to read boot sector");
	428	return -EIO;
	429	}
	430
	431	/* PRB is read */
b0516833	432	p_pbr = (struct pbr *)sbi->pbr_bh->b_data;
719c1e18 NJ	433
	434	/* check the validity of PBR */
	435	if (le16_to_cpu((p_pbr->signature)) != PBR_SIGNATURE) {
	436	exfat_msg(sb, KERN_ERR, "invalid boot record signature");
	437	ret = -EINVAL;
	438	goto free_bh;
	439	}
	440
	441
	442	/* check logical sector size */
b0516833	443	p_pbr = exfat_read_pbr_with_logical_sector(sb);
719c1e18 NJ	444	if (!p_pbr) {
	445	ret = -EIO;
	446	goto free_bh;
	447	}
	448
	449	/*
	450	* res_zero field must be filled with zero to prevent mounting
	451	* from FAT volume.
	452	*/
	453	if (memchr_inv(p_pbr->bpb.f64.res_zero, 0,
	454	sizeof(p_pbr->bpb.f64.res_zero))) {
	455	ret = -EINVAL;
	456	goto free_bh;
	457	}
	458
	459	p_bpb = (struct pbr64 *)p_pbr;
	460	if (!p_bpb->bsx.num_fats) {
	461	exfat_msg(sb, KERN_ERR, "bogus number of FAT structure");
	462	ret = -EINVAL;
	463	goto free_bh;
	464	}
	465
	466	sbi->sect_per_clus = 1 << p_bpb->bsx.sect_per_clus_bits;
	467	sbi->sect_per_clus_bits = p_bpb->bsx.sect_per_clus_bits;
	468	sbi->cluster_size_bits = sbi->sect_per_clus_bits + sb->s_blocksize_bits;
	469	sbi->cluster_size = 1 << sbi->cluster_size_bits;
	470	sbi->num_FAT_sectors = le32_to_cpu(p_bpb->bsx.fat_length);
	471	sbi->FAT1_start_sector = le32_to_cpu(p_bpb->bsx.fat_offset);
	472	sbi->FAT2_start_sector = p_bpb->bsx.num_fats == 1 ?
	473	sbi->FAT1_start_sector :
	474	sbi->FAT1_start_sector + sbi->num_FAT_sectors;
	475	sbi->data_start_sector = le32_to_cpu(p_bpb->bsx.clu_offset);
	476	sbi->num_sectors = le64_to_cpu(p_bpb->bsx.vol_length);
	477	/* because the cluster index starts with 2 */
	478	sbi->num_clusters = le32_to_cpu(p_bpb->bsx.clu_count) +
	479	EXFAT_RESERVED_CLUSTERS;
	480
	481	sbi->root_dir = le32_to_cpu(p_bpb->bsx.root_cluster);
	482	sbi->dentries_per_clu = 1 <<
	483	(sbi->cluster_size_bits - DENTRY_SIZE_BITS);
	484
	485	sbi->vol_flag = le16_to_cpu(p_bpb->bsx.vol_flags);
	486	sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
	487	sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
	488
	489	if (le16_to_cpu(p_bpb->bsx.vol_flags) & VOL_DIRTY) {
	490	sbi->vol_flag \|= VOL_DIRTY;
	491	exfat_msg(sb, KERN_WARNING,
	492	"Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
	493	}
	494
	495	/* exFAT file size is limited by a disk volume size */
	496	sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
	497	sbi->cluster_size_bits;
	498
	499	ret = exfat_create_upcase_table(sb);
	500	if (ret) {
	501	exfat_msg(sb, KERN_ERR, "failed to load upcase table");
	502	goto free_bh;
	503	}
	504
	505	ret = exfat_load_bitmap(sb);
	506	if (ret) {
	507	exfat_msg(sb, KERN_ERR, "failed to load alloc-bitmap");
508	goto free_upcase_table;
509	}
510
511	ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
512	if (ret) {
513	exfat_msg(sb, KERN_ERR, "failed to scan clusters");
514	goto free_alloc_bitmap;
515	}
516
517	return 0;
518
519	free_alloc_bitmap:
520	exfat_free_bitmap(sbi);
521	free_upcase_table:
522	exfat_free_upcase_table(sbi);
523	free_bh:
b0516833	524	brelse(sbi->pbr_bh);
719c1e18 NJ	525	return ret;
	526	}
	527
	528	static int exfat_fill_super(struct super_block sb, struct fs_context fc)
	529	{
	530	struct exfat_sb_info *sbi = sb->s_fs_info;
	531	struct exfat_mount_options *opts = &sbi->options;
	532	struct inode *root_inode;
	533	int err;
	534
	535	if (opts->allow_utime == (unsigned short)-1)
	536	opts->allow_utime = ~opts->fs_dmask & 0022;
	537
	538	if (opts->discard) {
	539	struct request_queue *q = bdev_get_queue(sb->s_bdev);
	540
b7e038a9	541	if (!blk_queue_discard(q)) {
719c1e18 NJ	542	exfat_msg(sb, KERN_WARNING,
719c1e18 NJ	543	"mounting with \"discard\" option, but the device does not support discard");
b7e038a9 PR	544	opts->discard = 0;
b7e038a9 PR	545	}
719c1e18 NJ	546	}
	547
	548	sb->s_flags \|= SB_NODIRATIME;
	549	sb->s_magic = EXFAT_SUPER_MAGIC;
	550	sb->s_op = &exfat_sops;
	551
674a9985	552	sb->s_time_gran = 10 * NSEC_PER_MSEC;
719c1e18 NJ	553	sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
	554	sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
	555
	556	err = __exfat_fill_super(sb);
	557	if (err) {
	558	exfat_msg(sb, KERN_ERR, "failed to recognize exfat type");
	559	goto check_nls_io;
	560	}
	561
	562	/* set up enough so that it can read an inode */
	563	exfat_hash_init(sb);
	564
	565	if (!strcmp(sbi->options.iocharset, "utf8"))
	566	opts->utf8 = 1;
	567	else {
	568	sbi->nls_io = load_nls(sbi->options.iocharset);
	569	if (!sbi->nls_io) {
	570	exfat_msg(sb, KERN_ERR, "IO charset %s not found",
	571	sbi->options.iocharset);
	572	err = -EINVAL;
	573	goto free_table;
	574	}
	575	}
	576
	577	if (sbi->options.utf8)
	578	sb->s_d_op = &exfat_utf8_dentry_ops;
	579	else
	580	sb->s_d_op = &exfat_dentry_ops;
	581
	582	root_inode = new_inode(sb);
	583	if (!root_inode) {
	584	exfat_msg(sb, KERN_ERR, "failed to allocate root inode.");
	585	err = -ENOMEM;
	586	goto free_table;
	587	}
	588
	589	root_inode->i_ino = EXFAT_ROOT_INO;
	590	inode_set_iversion(root_inode, 1);
	591	err = exfat_read_root(root_inode);
	592	if (err) {
	593	exfat_msg(sb, KERN_ERR, "failed to initialize root inode.");
	594	goto put_inode;
	595	}
	596
	597	exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
	598	insert_inode_hash(root_inode);
	599
	600	sb->s_root = d_make_root(root_inode);
	601	if (!sb->s_root) {
	602	exfat_msg(sb, KERN_ERR, "failed to get the root dentry");
	603	err = -ENOMEM;
	604	goto put_inode;
	605	}
	606
	607	return 0;
	608
	609	put_inode:
	610	iput(root_inode);
	611	sb->s_root = NULL;
	612
	613	free_table:
	614	exfat_free_upcase_table(sbi);
	615	exfat_free_bitmap(sbi);
b0516833	616	brelse(sbi->pbr_bh);
719c1e18 NJ	617
	618	check_nls_io:
	619	unload_nls(sbi->nls_io);
	620	exfat_free_iocharset(sbi);
	621	sb->s_fs_info = NULL;
	622	kfree(sbi);
	623	return err;
	624	}
	625
	626	static int exfat_get_tree(struct fs_context *fc)
	627	{
	628	return get_tree_bdev(fc, exfat_fill_super);
	629	}
	630
	631	static void exfat_free(struct fs_context *fc)
	632	{
	633	kfree(fc->s_fs_info);
	634	}
	635
	636	static const struct fs_context_operations exfat_context_ops = {
	637	.parse_param = exfat_parse_param,
	638	.get_tree = exfat_get_tree,
	639	.free = exfat_free,
	640	};
	641
	642	static int exfat_init_fs_context(struct fs_context *fc)
	643	{
	644	struct exfat_sb_info *sbi;
	645
	646	sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
	647	if (!sbi)
	648	return -ENOMEM;
	649
	650	mutex_init(&sbi->s_lock);
	651	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
	652	DEFAULT_RATELIMIT_BURST);
	653
	654	sbi->options.fs_uid = current_uid();
	655	sbi->options.fs_gid = current_gid();
	656	sbi->options.fs_fmask = current->fs->umask;
	657	sbi->options.fs_dmask = current->fs->umask;
	658	sbi->options.allow_utime = -1;
	659	sbi->options.iocharset = exfat_default_iocharset;
	660	sbi->options.errors = EXFAT_ERRORS_RO;
	661
	662	fc->s_fs_info = sbi;
	663	fc->ops = &exfat_context_ops;
	664	return 0;
	665	}
	666
	667	static struct file_system_type exfat_fs_type = {
	668	.owner = THIS_MODULE,
	669	.name = "exfat",
	670	.init_fs_context = exfat_init_fs_context,
9acd0d53	671	.parameters = exfat_parameters,
719c1e18 NJ	672	.kill_sb = kill_block_super,
	673	.fs_flags = FS_REQUIRES_DEV,
	674	};
	675
	676	static void exfat_inode_init_once(void *foo)
	677	{
	678	struct exfat_inode_info ei = (struct exfat_inode_info )foo;
	679
	680	INIT_HLIST_NODE(&ei->i_hash_fat);
	681	inode_init_once(&ei->vfs_inode);
	682	}
	683
	684	static int __init init_exfat_fs(void)
	685	{
	686	int err;
	687
	688	err = exfat_cache_init();
	689	if (err)
	690	return err;
	691
	692	exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
	693	sizeof(struct exfat_inode_info),
	694	0, SLAB_RECLAIM_ACCOUNT \| SLAB_MEM_SPREAD,
	695	exfat_inode_init_once);
	696	if (!exfat_inode_cachep) {
	697	err = -ENOMEM;
	698	goto shutdown_cache;
	699	}
	700
	701	err = register_filesystem(&exfat_fs_type);
	702	if (err)
	703	goto destroy_cache;
	704
	705	return 0;
	706
	707	destroy_cache:
	708	kmem_cache_destroy(exfat_inode_cachep);
	709	shutdown_cache:
	710	exfat_cache_shutdown();
	711	return err;
	712	}
	713
	714	static void __exit exit_exfat_fs(void)
	715	{
	716	/*
	717	* Make sure all delayed rcu free inodes are flushed before we
	718	* destroy cache.
	719	*/
	720	rcu_barrier();
	721	kmem_cache_destroy(exfat_inode_cachep);
	722	unregister_filesystem(&exfat_fs_type);
	723	exfat_cache_shutdown();
	724	}
	725
	726	module_init(init_exfat_fs);
	727	module_exit(exit_exfat_fs);
	728
cd76ac25	729	MODULE_ALIAS_FS("exfat");
719c1e18 NJ	730	MODULE_LICENSE("GPL");
	731	MODULE_DESCRIPTION("exFAT filesystem support");
	732	MODULE_AUTHOR("Samsung Electronics Co., Ltd.");