From 719c1e1829166da399903b13da6dcc5344e73449 Mon Sep 17 00:00:00 2001

From: Namjae Jeon <namjae.jeon@samsung.com>

Date: Mon, 2 Mar 2020 15:21:33 +0900

Subject: [Backport 719c1e182916] exfat: add super block operations

MIME-Version: 1.0

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This adds the implementation of superblock operations for exfat.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>

Reviewed-by: Pali Rohár <pali.rohar@gmail.com>

Reviewed-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

---

 src/super.c | 728 +++++++++++++++++++++++++++++++++++++++++++++++

 1 file changed, 728 insertions(+)

 create mode 100644 src/super.c

diff --git a/src/super.c b/src/super.c

new file mode 100644

index 0000000000000000000000000000000000000000..f06e0b53e39325937be7512f01c031c93917d9a8

--- /dev/null

+++ b/src/super.c

@@ -0,0 +1,728 @@

+// 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);

+	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;

+	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;

+

+	if (!sbi->pbr_bh) {

+		sbi->pbr_bh = sb_bread(sb, 0);

+		if (!sbi->pbr_bh) {

+			exfat_msg(sb, KERN_ERR, "failed to read boot sector");

+			return -ENOMEM;

+		}

+	}

+

+	bpb = (struct pbr64 *)sbi->pbr_bh->b_data;

+	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);

+	seq_printf(m, ",bps=%ld", sb->s_blocksize);

+	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,

+};

+

+static const struct fs_parameter_spec exfat_param_specs[] = {

+	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),

+	fsparam_flag("discard",			Opt_discard),

+	fsparam_s32("time_offset",		Opt_time_offset),

+	{}

+};

+

+static const struct fs_parameter_enum exfat_param_enums[] = {

+	{ Opt_errors,	"continue",		EXFAT_ERRORS_CONT },

+	{ Opt_errors,	"panic",		EXFAT_ERRORS_PANIC },

+	{ Opt_errors,	"remount-ro",		EXFAT_ERRORS_RO },

+	{}

+};

+

+static const struct fs_parameter_description exfat_parameters = {

+	.name		= "exfat",

+	.specs		= exfat_param_specs,

+	.enums		= exfat_param_enums,

+};

+

+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;

+	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_cache_init_inode(inode);

+	return 0;

+}

+

+static struct pbr *exfat_read_pbr_with_logical_sector(struct super_block *sb,

+		struct buffer_head **prev_bh)

+{

+	struct pbr *p_pbr = (struct pbr *) (*prev_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) {

+		struct buffer_head *bh = NULL;

+

+		__brelse(*prev_bh);

+		*prev_bh = NULL;

+

+		if (!sb_set_blocksize(sb, logical_sect)) {

+			exfat_msg(sb, KERN_ERR,

+				"unable to set blocksize %u", logical_sect);

+			return NULL;

+		}

+		bh = sb_bread(sb, 0);

+		if (!bh) {

+			exfat_msg(sb, KERN_ERR,

+				"unable to read boot sector (logical sector size = %lu)",

+				sb->s_blocksize);

+			return NULL;

+		}

+

+		*prev_bh = bh;

+		p_pbr = (struct 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 buffer_head *bh;

+	struct exfat_sb_info *sbi = EXFAT_SB(sb);

+

+	/* set block size to read super block */

+	sb_min_blocksize(sb, 512);

+

+	/* read boot sector */

+	bh = sb_bread(sb, 0);

+	if (!bh) {

+		exfat_msg(sb, KERN_ERR, "unable to read boot sector");

+		return -EIO;

+	}

+

+	/* PRB is read */

+	p_pbr = (struct 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, &bh;;

+	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(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 = 1;

+	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);

+

+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_LICENSE("GPL");

+MODULE_DESCRIPTION("exFAT filesystem support");

+MODULE_AUTHOR("Samsung Electronics Co., Ltd.");

-- 

2.31.1