Merge branch 'work.exfat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull exfat filesystem from Al Viro:
"Shiny new fs/exfat replacement for drivers/staging/exfat"

* 'work.exfat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
exfat: update file system parameter handling
staging: exfat: make staging/exfat and fs/exfat mutually exclusive
MAINTAINERS: add exfat filesystem
exfat: add Kconfig and Makefile
exfat: add nls operations
exfat: add misc operations
exfat: add exfat cache
exfat: add bitmap operations
exfat: add fat entry operations
exfat: add file operations
exfat: add directory operations
exfat: add inode operations
exfat: add super block operations
exfat: add in-memory and on-disk structures and headers

MAINTAINERS

···
 F:	include/uapi/linux/mdio.h
 F:	include/uapi/linux/mii.h
 
+EXFAT FILE SYSTEM
+M:	Namjae Jeon <[e-mail]>
+M:	Sungjong Seo <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+F:	fs/exfat/
+
 EXT2 FILE SYSTEM
 M:	Jan Kara <[e-mail]>
 L:	[e-mail]

fs/Kconfig

···
 endif # BLOCK
 
 if BLOCK
-menu "DOS/FAT/NT Filesystems"
+menu "DOS/FAT/EXFAT/NT Filesystems"
 
 source "fs/fat/Kconfig"
+source "fs/exfat/Kconfig"
 source "fs/ntfs/Kconfig"
 
 endmenu

fs/Makefile

···
 obj-$(CONFIG_CODA_FS)		+= coda/
 obj-$(CONFIG_MINIX_FS)		+= minix/
 obj-$(CONFIG_FAT_FS)		+= fat/
+obj-$(CONFIG_EXFAT_FS)		+= exfat/
 obj-$(CONFIG_BFS_FS)		+= bfs/
 obj-$(CONFIG_ISO9660_FS)	+= isofs/
 obj-$(CONFIG_HFSPLUS_FS)	+= hfsplus/ # Before hfs to find wrapped HFS+

fs/exfat/Kconfig

···
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+config EXFAT_FS
+	tristate "exFAT filesystem support"
+	select NLS
+	help
+	  This allows you to mount devices formatted with the exFAT file system.
+	  exFAT is typically used on SD-Cards or USB sticks.
+
+	  To compile this as a module, choose M here: the module will be called
+	  exfat.
+
+config EXFAT_DEFAULT_IOCHARSET
+	string "Default iocharset for exFAT"
+	default "utf8"
+	depends on EXFAT_FS
+	help
+	  Set this to the default input/output character set to use for
+	  converting between the encoding is used for user visible filename and
+	  UTF-16 character that exfat filesystem use, and can be overridden with
+	  the "iocharset" mount option for exFAT filesystems.

fs/exfat/Makefile

···
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Makefile for the linux exFAT filesystem support.
+#
+obj-$(CONFIG_EXFAT_FS) += exfat.o
+
+exfat-y	:= inode.o namei.o dir.o super.o fatent.o cache.o nls.o misc.o \
+	   file.o balloc.o

fs/exfat/balloc.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+
+static const unsigned char free_bit[] = {
+	0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2,/*  0 ~  19*/
+	0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3,/* 20 ~  39*/
+	0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/* 40 ~  59*/
+	0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4,/* 60 ~  79*/
+	0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2,/* 80 ~  99*/
+	0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3,/*100 ~ 119*/
+	0, 1, 0, 2, 0, 1, 0, 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/*120 ~ 139*/
+	0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5,/*140 ~ 159*/
+	0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2,/*160 ~ 179*/
+	0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3,/*180 ~ 199*/
+	0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/*200 ~ 219*/
+	0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4,/*220 ~ 239*/
+	0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0                /*240 ~ 254*/
+};
+
+static const unsigned char used_bit[] = {
+	0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3,/*  0 ~  19*/
+	2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4,/* 20 ~  39*/
+	2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5,/* 40 ~  59*/
+	4, 5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,/* 60 ~  79*/
+	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4,/* 80 ~  99*/
+	3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6,/*100 ~ 119*/
+	4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4,/*120 ~ 139*/
+	3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,/*140 ~ 159*/
+	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5,/*160 ~ 179*/
+	4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4, 5,/*180 ~ 199*/
+	3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6,/*200 ~ 219*/
+	5, 6, 6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,/*220 ~ 239*/
+	4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8             /*240 ~ 255*/
+};
+
+/*
+ *  Allocation Bitmap Management Functions
+ */
+static int exfat_allocate_bitmap(struct super_block *sb,
+		struct exfat_dentry *ep)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	long long map_size;
+	unsigned int i, need_map_size;
+	sector_t sector;
+
+	sbi->map_clu = le32_to_cpu(ep->dentry.bitmap.start_clu);
+	map_size = le64_to_cpu(ep->dentry.bitmap.size);
+	need_map_size = ((EXFAT_DATA_CLUSTER_COUNT(sbi) - 1) / BITS_PER_BYTE)
+		+ 1;
+	if (need_map_size != map_size) {
+		exfat_msg(sb, KERN_ERR,
+				"bogus allocation bitmap size(need : %u, cur : %lld)",
+				need_map_size, map_size);
+		/*
+		 * Only allowed when bogus allocation
+		 * bitmap size is large
+		 */
+		if (need_map_size > map_size)
+			return -EIO;
+	}
+	sbi->map_sectors = ((need_map_size - 1) >>
+			(sb->s_blocksize_bits)) + 1;
+	sbi->vol_amap = kmalloc_array(sbi->map_sectors,
+				sizeof(struct buffer_head *), GFP_KERNEL);
+	if (!sbi->vol_amap)
+		return -ENOMEM;
+
+	sector = exfat_cluster_to_sector(sbi, sbi->map_clu);
+	for (i = 0; i < sbi->map_sectors; i++) {
+		sbi->vol_amap[i] = sb_bread(sb, sector + i);
+		if (!sbi->vol_amap[i]) {
+			/* release all buffers and free vol_amap */
+			int j = 0;
+
+			while (j < i)
+				brelse(sbi->vol_amap[j++]);
+
+			kfree(sbi->vol_amap);
+			sbi->vol_amap = NULL;
+			return -EIO;
+		}
+	}
+
+	sbi->pbr_bh = NULL;
+	return 0;
+}
+
+int exfat_load_bitmap(struct super_block *sb)
+{
+	unsigned int i, type;
+	struct exfat_chain clu;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	exfat_chain_set(&clu, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
+	while (clu.dir != EXFAT_EOF_CLUSTER) {
+		for (i = 0; i < sbi->dentries_per_clu; i++) {
+			struct exfat_dentry *ep;
+			struct buffer_head *bh;
+
+			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
+			if (!ep)
+				return -EIO;
+
+			type = exfat_get_entry_type(ep);
+			if (type == TYPE_UNUSED)
+				break;
+			if (type != TYPE_BITMAP)
+				continue;
+			if (ep->dentry.bitmap.flags == 0x0) {
+				int err;
+
+				err = exfat_allocate_bitmap(sb, ep);
+				brelse(bh);
+				return err;
+			}
+			brelse(bh);
+		}
+
+		if (exfat_get_next_cluster(sb, &clu.dir))
+			return -EIO;
+	}
+
+	return -EINVAL;
+}
+
+void exfat_free_bitmap(struct exfat_sb_info *sbi)
+{
+	int i;
+
+	brelse(sbi->pbr_bh);
+
+	for (i = 0; i < sbi->map_sectors; i++)
+		__brelse(sbi->vol_amap[i]);
+
+	kfree(sbi->vol_amap);
+}
+
+/*
+ * If the value of "clu" is 0, it means cluster 2 which is the first cluster of
+ * the cluster heap.
+ */
+int exfat_set_bitmap(struct inode *inode, unsigned int clu)
+{
+	int i, b;
+	unsigned int ent_idx;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	WARN_ON(clu < EXFAT_FIRST_CLUSTER);
+	ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
+	i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
+	b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
+
+	set_bit_le(b, sbi->vol_amap[i]->b_data);
+	exfat_update_bh(sb, sbi->vol_amap[i], IS_DIRSYNC(inode));
+	return 0;
+}
+
+/*
+ * If the value of "clu" is 0, it means cluster 2 which is the first cluster of
+ * the cluster heap.
+ */
+void exfat_clear_bitmap(struct inode *inode, unsigned int clu)
+{
+	int i, b;
+	unsigned int ent_idx;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_mount_options *opts = &sbi->options;
+
+	WARN_ON(clu < EXFAT_FIRST_CLUSTER);
+	ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
+	i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
+	b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
+
+	clear_bit_le(b, sbi->vol_amap[i]->b_data);
+	exfat_update_bh(sb, sbi->vol_amap[i], IS_DIRSYNC(inode));
+
+	if (opts->discard) {
+		int ret_discard;
+
+		ret_discard = sb_issue_discard(sb,
+			exfat_cluster_to_sector(sbi, clu +
+						EXFAT_RESERVED_CLUSTERS),
+			(1 << sbi->sect_per_clus_bits), GFP_NOFS, 0);
+
+		if (ret_discard == -EOPNOTSUPP) {
+			exfat_msg(sb, KERN_ERR,
+				"discard not supported by device, disabling");
+			opts->discard = 0;
+		}
+	}
+}
+
+/*
+ * If the value of "clu" is 0, it means cluster 2 which is the first cluster of
+ * the cluster heap.
+ */
+unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu)
+{
+	unsigned int i, map_i, map_b, ent_idx;
+	unsigned int clu_base, clu_free;
+	unsigned char k, clu_mask;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	WARN_ON(clu < EXFAT_FIRST_CLUSTER);
+	ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
+	clu_base = BITMAP_ENT_TO_CLUSTER(ent_idx & ~(BITS_PER_BYTE_MASK));
+	clu_mask = IGNORED_BITS_REMAINED(clu, clu_base);
+
+	map_i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
+	map_b = BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent_idx);
+
+	for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters;
+	     i += BITS_PER_BYTE) {
+		k = *(sbi->vol_amap[map_i]->b_data + map_b);
+		if (clu_mask > 0) {
+			k |= clu_mask;
+			clu_mask = 0;
+		}
+		if (k < 0xFF) {
+			clu_free = clu_base + free_bit[k];
+			if (clu_free < sbi->num_clusters)
+				return clu_free;
+		}
+		clu_base += BITS_PER_BYTE;
+
+		if (++map_b >= sb->s_blocksize ||
+		    clu_base >= sbi->num_clusters) {
+			if (++map_i >= sbi->map_sectors) {
+				clu_base = EXFAT_FIRST_CLUSTER;
+				map_i = 0;
+			}
+			map_b = 0;
+		}
+	}
+
+	return EXFAT_EOF_CLUSTER;
+}
+
+int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	unsigned int count = 0;
+	unsigned int i, map_i = 0, map_b = 0;
+	unsigned int total_clus = EXFAT_DATA_CLUSTER_COUNT(sbi);
+	unsigned int last_mask = total_clus & BITS_PER_BYTE_MASK;
+	unsigned char clu_bits;
+	const unsigned char last_bit_mask[] = {0, 0b00000001, 0b00000011,
+		0b00000111, 0b00001111, 0b00011111, 0b00111111, 0b01111111};
+
+	total_clus &= ~last_mask;
+	for (i = 0; i < total_clus; i += BITS_PER_BYTE) {
+		clu_bits = *(sbi->vol_amap[map_i]->b_data + map_b);
+		count += used_bit[clu_bits];
+		if (++map_b >= (unsigned int)sb->s_blocksize) {
+			map_i++;
+			map_b = 0;
+		}
+	}
+
+	if (last_mask) {
+		clu_bits = *(sbi->vol_amap[map_i]->b_data + map_b);
+		clu_bits &= last_bit_mask[last_mask];
+		count += used_bit[clu_bits];
+	}
+
+	*ret_count = count;
+	return 0;
+}

fs/exfat/cache.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  linux/fs/fat/cache.c
+ *
+ *  Written 1992,1993 by Werner Almesberger
+ *
+ *  Mar 1999. AV. Changed cache, so that it uses the starting cluster instead
+ *	of inode number.
+ *  May 1999. AV. Fixed the bogosity with FAT32 (read "FAT28"). Fscking lusers.
+ *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+#include <linux/buffer_head.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+
+#define EXFAT_CACHE_VALID	0
+#define EXFAT_MAX_CACHE		16
+
+struct exfat_cache {
+	struct list_head cache_list;
+	unsigned int nr_contig;	/* number of contiguous clusters */
+	unsigned int fcluster;	/* cluster number in the file. */
+	unsigned int dcluster;	/* cluster number on disk. */
+};
+
+struct exfat_cache_id {
+	unsigned int id;
+	unsigned int nr_contig;
+	unsigned int fcluster;
+	unsigned int dcluster;
+};
+
+static struct kmem_cache *exfat_cachep;
+
+static void exfat_cache_init_once(void *c)
+{
+	struct exfat_cache *cache = (struct exfat_cache *)c;
+
+	INIT_LIST_HEAD(&cache->cache_list);
+}
+
+int exfat_cache_init(void)
+{
+	exfat_cachep = kmem_cache_create("exfat_cache",
+				sizeof(struct exfat_cache),
+				0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
+				exfat_cache_init_once);
+	if (!exfat_cachep)
+		return -ENOMEM;
+	return 0;
+}
+
+void exfat_cache_shutdown(void)
+{
+	if (!exfat_cachep)
+		return;
+	kmem_cache_destroy(exfat_cachep);
+}
+
+void exfat_cache_init_inode(struct inode *inode)
+{
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+
+	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);
+}
+
+static inline struct exfat_cache *exfat_cache_alloc(void)
+{
+	return kmem_cache_alloc(exfat_cachep, GFP_NOFS);
+}
+
+static inline void exfat_cache_free(struct exfat_cache *cache)
+{
+	WARN_ON(!list_empty(&cache->cache_list));
+	kmem_cache_free(exfat_cachep, cache);
+}
+
+static inline void exfat_cache_update_lru(struct inode *inode,
+		struct exfat_cache *cache)
+{
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+
+	if (ei->cache_lru.next != &cache->cache_list)
+		list_move(&cache->cache_list, &ei->cache_lru);
+}
+
+static unsigned int exfat_cache_lookup(struct inode *inode,
+		unsigned int fclus, struct exfat_cache_id *cid,
+		unsigned int *cached_fclus, unsigned int *cached_dclus)
+{
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	static struct exfat_cache nohit = { .fcluster = 0, };
+	struct exfat_cache *hit = &nohit, *p;
+	unsigned int offset = EXFAT_EOF_CLUSTER;
+
+	spin_lock(&ei->cache_lru_lock);
+	list_for_each_entry(p, &ei->cache_lru, cache_list) {
+		/* Find the cache of "fclus" or nearest cache. */
+		if (p->fcluster <= fclus && hit->fcluster < p->fcluster) {
+			hit = p;
+			if (hit->fcluster + hit->nr_contig < fclus) {
+				offset = hit->nr_contig;
+			} else {
+				offset = fclus - hit->fcluster;
+				break;
+			}
+		}
+	}
+	if (hit != &nohit) {
+		exfat_cache_update_lru(inode, hit);
+
+		cid->id = ei->cache_valid_id;
+		cid->nr_contig = hit->nr_contig;
+		cid->fcluster = hit->fcluster;
+		cid->dcluster = hit->dcluster;
+		*cached_fclus = cid->fcluster + offset;
+		*cached_dclus = cid->dcluster + offset;
+	}
+	spin_unlock(&ei->cache_lru_lock);
+
+	return offset;
+}
+
+static struct exfat_cache *exfat_cache_merge(struct inode *inode,
+		struct exfat_cache_id *new)
+{
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	struct exfat_cache *p;
+
+	list_for_each_entry(p, &ei->cache_lru, cache_list) {
+		/* Find the same part as "new" in cluster-chain. */
+		if (p->fcluster == new->fcluster) {
+			if (new->nr_contig > p->nr_contig)
+				p->nr_contig = new->nr_contig;
+			return p;
+		}
+	}
+	return NULL;
+}
+
+static void exfat_cache_add(struct inode *inode,
+		struct exfat_cache_id *new)
+{
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	struct exfat_cache *cache, *tmp;
+
+	if (new->fcluster == EXFAT_EOF_CLUSTER) /* dummy cache */
+		return;
+
+	spin_lock(&ei->cache_lru_lock);
+	if (new->id != EXFAT_CACHE_VALID &&
+	    new->id != ei->cache_valid_id)
+		goto unlock;	/* this cache was invalidated */
+
+	cache = exfat_cache_merge(inode, new);
+	if (cache == NULL) {
+		if (ei->nr_caches < EXFAT_MAX_CACHE) {
+			ei->nr_caches++;
+			spin_unlock(&ei->cache_lru_lock);
+
+			tmp = exfat_cache_alloc();
+			if (!tmp) {
+				spin_lock(&ei->cache_lru_lock);
+				ei->nr_caches--;
+				spin_unlock(&ei->cache_lru_lock);
+				return;
+			}
+
+			spin_lock(&ei->cache_lru_lock);
+			cache = exfat_cache_merge(inode, new);
+			if (cache != NULL) {
+				ei->nr_caches--;
+				exfat_cache_free(tmp);
+				goto out_update_lru;
+			}
+			cache = tmp;
+		} else {
+			struct list_head *p = ei->cache_lru.prev;
+
+			cache = list_entry(p,
+					struct exfat_cache, cache_list);
+		}
+		cache->fcluster = new->fcluster;
+		cache->dcluster = new->dcluster;
+		cache->nr_contig = new->nr_contig;
+	}
+out_update_lru:
+	exfat_cache_update_lru(inode, cache);
+unlock:
+	spin_unlock(&ei->cache_lru_lock);
+}
+
+/*
+ * Cache invalidation occurs rarely, thus the LRU chain is not updated. It
+ * fixes itself after a while.
+ */
+static void __exfat_cache_inval_inode(struct inode *inode)
+{
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	struct exfat_cache *cache;
+
+	while (!list_empty(&ei->cache_lru)) {
+		cache = list_entry(ei->cache_lru.next,
+				   struct exfat_cache, cache_list);
+		list_del_init(&cache->cache_list);
+		ei->nr_caches--;
+		exfat_cache_free(cache);
+	}
+	/* Update. The copy of caches before this id is discarded. */
+	ei->cache_valid_id++;
+	if (ei->cache_valid_id == EXFAT_CACHE_VALID)
+		ei->cache_valid_id++;
+}
+
+void exfat_cache_inval_inode(struct inode *inode)
+{
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+
+	spin_lock(&ei->cache_lru_lock);
+	__exfat_cache_inval_inode(inode);
+	spin_unlock(&ei->cache_lru_lock);
+}
+
+static inline int cache_contiguous(struct exfat_cache_id *cid,
+		unsigned int dclus)
+{
+	cid->nr_contig++;
+	return cid->dcluster + cid->nr_contig == dclus;
+}
+
+static inline void cache_init(struct exfat_cache_id *cid,
+		unsigned int fclus, unsigned int dclus)
+{
+	cid->id = EXFAT_CACHE_VALID;
+	cid->fcluster = fclus;
+	cid->dcluster = dclus;
+	cid->nr_contig = 0;
+}
+
+int exfat_get_cluster(struct inode *inode, unsigned int cluster,
+		unsigned int *fclus, unsigned int *dclus,
+		unsigned int *last_dclus, int allow_eof)
+{
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	unsigned int limit = sbi->num_clusters;
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	struct exfat_cache_id cid;
+	unsigned int content;
+
+	if (ei->start_clu == EXFAT_FREE_CLUSTER) {
+		exfat_fs_error(sb,
+			"invalid access to exfat cache (entry 0x%08x)",
+			ei->start_clu);
+		return -EIO;
+	}
+
+	*fclus = 0;
+	*dclus = ei->start_clu;
+	*last_dclus = *dclus;
+
+	/*
+	 * Don`t use exfat_cache if zero offset or non-cluster allocation
+	 */
+	if (cluster == 0 || *dclus == EXFAT_EOF_CLUSTER)
+		return 0;
+
+	cache_init(&cid, EXFAT_EOF_CLUSTER, EXFAT_EOF_CLUSTER);
+
+	if (exfat_cache_lookup(inode, cluster, &cid, fclus, dclus) ==
+			EXFAT_EOF_CLUSTER) {
+		/*
+		 * dummy, always not contiguous
+		 * This is reinitialized by cache_init(), later.
+		 */
+		WARN_ON(cid.id != EXFAT_CACHE_VALID ||
+			cid.fcluster != EXFAT_EOF_CLUSTER ||
+			cid.dcluster != EXFAT_EOF_CLUSTER ||
+			cid.nr_contig != 0);
+	}
+
+	if (*fclus == cluster)
+		return 0;
+
+	while (*fclus < cluster) {
+		/* prevent the infinite loop of cluster chain */
+		if (*fclus > limit) {
+			exfat_fs_error(sb,
+				"detected the cluster chain loop (i_pos %u)",
+				(*fclus));
+			return -EIO;
+		}
+
+		if (exfat_ent_get(sb, *dclus, &content))
+			return -EIO;
+
+		*last_dclus = *dclus;
+		*dclus = content;
+		(*fclus)++;
+
+		if (content == EXFAT_EOF_CLUSTER) {
+			if (!allow_eof) {
+				exfat_fs_error(sb,
+				       "invalid cluster chain (i_pos %u, last_clus 0x%08x is EOF)",
+				       *fclus, (*last_dclus));
+				return -EIO;
+			}
+
+			break;
+		}
+
+		if (!cache_contiguous(&cid, *dclus))
+			cache_init(&cid, *fclus, *dclus);
+	}
+
+	exfat_cache_add(inode, &cid);
+	return 0;
+}

fs/exfat/dir.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/slab.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+
+static int exfat_extract_uni_name(struct exfat_dentry *ep,
+		unsigned short *uniname)
+{
+	int i, len = 0;
+
+	for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {
+		*uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]);
+		if (*uniname == 0x0)
+			return len;
+		uniname++;
+		len++;
+	}
+
+	*uniname = 0x0;
+	return len;
+
+}
+
+static void exfat_get_uniname_from_ext_entry(struct super_block *sb,
+		struct exfat_chain *p_dir, int entry, unsigned short *uniname)
+{
+	int i;
+	struct exfat_dentry *ep;
+	struct exfat_entry_set_cache *es;
+
+	es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES, &ep);
+	if (!es)
+		return;
+
+	if (es->num_entries < 3)
+		goto free_es;
+
+	ep += 2;
+
+	/*
+	 * First entry  : file entry
+	 * Second entry : stream-extension entry
+	 * Third entry  : first file-name entry
+	 * So, the index of first file-name dentry should start from 2.
+	 */
+	for (i = 2; i < es->num_entries; i++, ep++) {
+		/* end of name entry */
+		if (exfat_get_entry_type(ep) != TYPE_EXTEND)
+			goto free_es;
+
+		exfat_extract_uni_name(ep, uniname);
+		uniname += EXFAT_FILE_NAME_LEN;
+	}
+
+free_es:
+	kfree(es);
+}
+
+/* read a directory entry from the opened directory */
+static int exfat_readdir(struct inode *inode, struct exfat_dir_entry *dir_entry)
+{
+	int i, dentries_per_clu, dentries_per_clu_bits = 0;
+	unsigned int type, clu_offset;
+	sector_t sector;
+	struct exfat_chain dir, clu;
+	struct exfat_uni_name uni_name;
+	struct exfat_dentry *ep;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	unsigned int dentry = ei->rwoffset & 0xFFFFFFFF;
+	struct buffer_head *bh;
+
+	/* check if the given file ID is opened */
+	if (ei->type != TYPE_DIR)
+		return -EPERM;
+
+	if (ei->entry == -1)
+		exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
+	else
+		exfat_chain_set(&dir, ei->start_clu,
+			EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
+
+	dentries_per_clu = sbi->dentries_per_clu;
+	dentries_per_clu_bits = ilog2(dentries_per_clu);
+
+	clu_offset = dentry >> dentries_per_clu_bits;
+	exfat_chain_dup(&clu, &dir);
+
+	if (clu.flags == ALLOC_NO_FAT_CHAIN) {
+		clu.dir += clu_offset;
+		clu.size -= clu_offset;
+	} else {
+		/* hint_information */
+		if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER &&
+		    ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) {
+			clu_offset -= ei->hint_bmap.off;
+			clu.dir = ei->hint_bmap.clu;
+		}
+
+		while (clu_offset > 0) {
+			if (exfat_get_next_cluster(sb, &(clu.dir)))
+				return -EIO;
+
+			clu_offset--;
+		}
+	}
+
+	while (clu.dir != EXFAT_EOF_CLUSTER) {
+		i = dentry & (dentries_per_clu - 1);
+
+		for ( ; i < dentries_per_clu; i++, dentry++) {
+			ep = exfat_get_dentry(sb, &clu, i, &bh, &sector);
+			if (!ep)
+				return -EIO;
+
+			type = exfat_get_entry_type(ep);
+			if (type == TYPE_UNUSED) {
+				brelse(bh);
+				break;
+			}
+
+			if (type != TYPE_FILE && type != TYPE_DIR) {
+				brelse(bh);
+				continue;
+			}
+
+			dir_entry->attr = le16_to_cpu(ep->dentry.file.attr);
+			exfat_get_entry_time(sbi, &dir_entry->crtime,
+					ep->dentry.file.create_tz,
+					ep->dentry.file.create_time,
+					ep->dentry.file.create_date,
+					ep->dentry.file.create_time_ms);
+			exfat_get_entry_time(sbi, &dir_entry->mtime,
+					ep->dentry.file.modify_tz,
+					ep->dentry.file.modify_time,
+					ep->dentry.file.modify_date,
+					ep->dentry.file.modify_time_ms);
+			exfat_get_entry_time(sbi, &dir_entry->atime,
+					ep->dentry.file.access_tz,
+					ep->dentry.file.access_time,
+					ep->dentry.file.access_date,
+					0);
+
+			*uni_name.name = 0x0;
+			exfat_get_uniname_from_ext_entry(sb, &dir, dentry,
+				uni_name.name);
+			exfat_utf16_to_nls(sb, &uni_name,
+				dir_entry->namebuf.lfn,
+				dir_entry->namebuf.lfnbuf_len);
+			brelse(bh);
+
+			ep = exfat_get_dentry(sb, &clu, i + 1, &bh, NULL);
+			if (!ep)
+				return -EIO;
+			dir_entry->size =
+				le64_to_cpu(ep->dentry.stream.valid_size);
+			brelse(bh);
+
+			ei->hint_bmap.off = dentry >> dentries_per_clu_bits;
+			ei->hint_bmap.clu = clu.dir;
+
+			ei->rwoffset = ++dentry;
+			return 0;
+		}
+
+		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
+			if (--clu.size > 0)
+				clu.dir++;
+			else
+				clu.dir = EXFAT_EOF_CLUSTER;
+		} else {
+			if (exfat_get_next_cluster(sb, &(clu.dir)))
+				return -EIO;
+		}
+	}
+
+	dir_entry->namebuf.lfn[0] = '\0';
+	ei->rwoffset = dentry;
+	return 0;
+}
+
+static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb)
+{
+	nb->lfn = NULL;
+	nb->lfnbuf_len = 0;
+}
+
+static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb)
+{
+	nb->lfn = __getname();
+	if (!nb->lfn)
+		return -ENOMEM;
+	nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE;
+	return 0;
+}
+
+static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb)
+{
+	if (!nb->lfn)
+		return;
+
+	__putname(nb->lfn);
+	exfat_init_namebuf(nb);
+}
+
+/* skip iterating emit_dots when dir is empty */
+#define ITER_POS_FILLED_DOTS    (2)
+static int exfat_iterate(struct file *filp, struct dir_context *ctx)
+{
+	struct inode *inode = filp->f_path.dentry->d_inode;
+	struct super_block *sb = inode->i_sb;
+	struct inode *tmp;
+	struct exfat_dir_entry de;
+	struct exfat_dentry_namebuf *nb = &(de.namebuf);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	unsigned long inum;
+	loff_t cpos, i_pos;
+	int err = 0, fake_offset = 0;
+
+	exfat_init_namebuf(nb);
+	mutex_lock(&EXFAT_SB(sb)->s_lock);
+
+	cpos = ctx->pos;
+	if (!dir_emit_dots(filp, ctx))
+		goto unlock;
+
+	if (ctx->pos == ITER_POS_FILLED_DOTS) {
+		cpos = 0;
+		fake_offset = 1;
+	}
+
+	if (cpos & (DENTRY_SIZE - 1)) {
+		err = -ENOENT;
+		goto unlock;
+	}
+
+	/* name buffer should be allocated before use */
+	err = exfat_alloc_namebuf(nb);
+	if (err)
+		goto unlock;
+get_new:
+	ei->rwoffset = EXFAT_B_TO_DEN(cpos);
+
+	if (cpos >= i_size_read(inode))
+		goto end_of_dir;
+
+	err = exfat_readdir(inode, &de);
+	if (err) {
+		/*
+		 * At least we tried to read a sector.  Move cpos to next sector
+		 * position (should be aligned).
+		 */
+		if (err == -EIO) {
+			cpos += 1 << (sb->s_blocksize_bits);
+			cpos &= ~(sb->s_blocksize - 1);
+		}
+
+		err = -EIO;
+		goto end_of_dir;
+	}
+
+	cpos = EXFAT_DEN_TO_B(ei->rwoffset);
+
+	if (!nb->lfn[0])
+		goto end_of_dir;
+
+	i_pos = ((loff_t)ei->start_clu << 32) |
+		((ei->rwoffset - 1) & 0xffffffff);
+	tmp = exfat_iget(sb, i_pos);
+	if (tmp) {
+		inum = tmp->i_ino;
+		iput(tmp);
+	} else {
+		inum = iunique(sb, EXFAT_ROOT_INO);
+	}
+
+	/*
+	 * Before calling dir_emit(), sb_lock should be released.
+	 * Because page fault can occur in dir_emit() when the size
+	 * of buffer given from user is larger than one page size.
+	 */
+	mutex_unlock(&EXFAT_SB(sb)->s_lock);
+	if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum,
+			(de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG))
+		goto out_unlocked;
+	mutex_lock(&EXFAT_SB(sb)->s_lock);
+	ctx->pos = cpos;
+	goto get_new;
+
+end_of_dir:
+	if (!cpos && fake_offset)
+		cpos = ITER_POS_FILLED_DOTS;
+	ctx->pos = cpos;
+unlock:
+	mutex_unlock(&EXFAT_SB(sb)->s_lock);
+out_unlocked:
+	/*
+	 * To improve performance, free namebuf after unlock sb_lock.
+	 * If namebuf is not allocated, this function do nothing
+	 */
+	exfat_free_namebuf(nb);
+	return err;
+}
+
+const struct file_operations exfat_dir_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= generic_read_dir,
+	.iterate	= exfat_iterate,
+	.fsync		= generic_file_fsync,
+};
+
+int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu)
+{
+	int ret;
+
+	exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN);
+
+	ret = exfat_alloc_cluster(inode, 1, clu);
+	if (ret)
+		return ret;
+
+	return exfat_zeroed_cluster(inode, clu->dir);
+}
+
+int exfat_calc_num_entries(struct exfat_uni_name *p_uniname)
+{
+	int len;
+
+	len = p_uniname->name_len;
+	if (len == 0)
+		return -EINVAL;
+
+	/* 1 file entry + 1 stream entry + name entries */
+	return ((len - 1) / EXFAT_FILE_NAME_LEN + 3);
+}
+
+unsigned int exfat_get_entry_type(struct exfat_dentry *ep)
+{
+	if (ep->type == EXFAT_UNUSED)
+		return TYPE_UNUSED;
+	if (IS_EXFAT_DELETED(ep->type))
+		return TYPE_DELETED;
+	if (ep->type == EXFAT_INVAL)
+		return TYPE_INVALID;
+	if (IS_EXFAT_CRITICAL_PRI(ep->type)) {
+		if (ep->type == EXFAT_BITMAP)
+			return TYPE_BITMAP;
+		if (ep->type == EXFAT_UPCASE)
+			return TYPE_UPCASE;
+		if (ep->type == EXFAT_VOLUME)
+			return TYPE_VOLUME;
+		if (ep->type == EXFAT_FILE) {
+			if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR)
+				return TYPE_DIR;
+			return TYPE_FILE;
+		}
+		return TYPE_CRITICAL_PRI;
+	}
+	if (IS_EXFAT_BENIGN_PRI(ep->type)) {
+		if (ep->type == EXFAT_GUID)
+			return TYPE_GUID;
+		if (ep->type == EXFAT_PADDING)
+			return TYPE_PADDING;
+		if (ep->type == EXFAT_ACLTAB)
+			return TYPE_ACLTAB;
+		return TYPE_BENIGN_PRI;
+	}
+	if (IS_EXFAT_CRITICAL_SEC(ep->type)) {
+		if (ep->type == EXFAT_STREAM)
+			return TYPE_STREAM;
+		if (ep->type == EXFAT_NAME)
+			return TYPE_EXTEND;
+		if (ep->type == EXFAT_ACL)
+			return TYPE_ACL;
+		return TYPE_CRITICAL_SEC;
+	}
+	return TYPE_BENIGN_SEC;
+}
+
+static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type)
+{
+	if (type == TYPE_UNUSED) {
+		ep->type = EXFAT_UNUSED;
+	} else if (type == TYPE_DELETED) {
+		ep->type &= EXFAT_DELETE;
+	} else if (type == TYPE_STREAM) {
+		ep->type = EXFAT_STREAM;
+	} else if (type == TYPE_EXTEND) {
+		ep->type = EXFAT_NAME;
+	} else if (type == TYPE_BITMAP) {
+		ep->type = EXFAT_BITMAP;
+	} else if (type == TYPE_UPCASE) {
+		ep->type = EXFAT_UPCASE;
+	} else if (type == TYPE_VOLUME) {
+		ep->type = EXFAT_VOLUME;
+	} else if (type == TYPE_DIR) {
+		ep->type = EXFAT_FILE;
+		ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR);
+	} else if (type == TYPE_FILE) {
+		ep->type = EXFAT_FILE;
+		ep->dentry.file.attr = cpu_to_le16(ATTR_ARCHIVE);
+	}
+}
+
+static void exfat_init_stream_entry(struct exfat_dentry *ep,
+		unsigned char flags, unsigned int start_clu,
+		unsigned long long size)
+{
+	exfat_set_entry_type(ep, TYPE_STREAM);
+	ep->dentry.stream.flags = flags;
+	ep->dentry.stream.start_clu = cpu_to_le32(start_clu);
+	ep->dentry.stream.valid_size = cpu_to_le64(size);
+	ep->dentry.stream.size = cpu_to_le64(size);
+}
+
+static void exfat_init_name_entry(struct exfat_dentry *ep,
+		unsigned short *uniname)
+{
+	int i;
+
+	exfat_set_entry_type(ep, TYPE_EXTEND);
+	ep->dentry.name.flags = 0x0;
+
+	for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {
+		ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname);
+		if (*uniname == 0x0)
+			break;
+		uniname++;
+	}
+}
+
+int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir,
+		int entry, unsigned int type, unsigned int start_clu,
+		unsigned long long size)
+{
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct timespec64 ts = current_time(inode);
+	sector_t sector;
+	struct exfat_dentry *ep;
+	struct buffer_head *bh;
+
+	/*
+	 * We cannot use exfat_get_dentry_set here because file ep is not
+	 * initialized yet.
+	 */
+	ep = exfat_get_dentry(sb, p_dir, entry, &bh, &sector);
+	if (!ep)
+		return -EIO;
+
+	exfat_set_entry_type(ep, type);
+	exfat_set_entry_time(sbi, &ts,
+			&ep->dentry.file.create_tz,
+			&ep->dentry.file.create_time,
+			&ep->dentry.file.create_date,
+			&ep->dentry.file.create_time_ms);
+	exfat_set_entry_time(sbi, &ts,
+			&ep->dentry.file.modify_tz,
+			&ep->dentry.file.modify_time,
+			&ep->dentry.file.modify_date,
+			&ep->dentry.file.modify_time_ms);
+	exfat_set_entry_time(sbi, &ts,
+			&ep->dentry.file.access_tz,
+			&ep->dentry.file.access_time,
+			&ep->dentry.file.access_date,
+			NULL);
+
+	exfat_update_bh(sb, bh, IS_DIRSYNC(inode));
+	brelse(bh);
+
+	ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, &sector);
+	if (!ep)
+		return -EIO;
+
+	exfat_init_stream_entry(ep,
+		(type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN,
+		start_clu, size);
+	exfat_update_bh(sb, bh, IS_DIRSYNC(inode));
+	brelse(bh);
+
+	return 0;
+}
+
+int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
+		int entry)
+{
+	struct super_block *sb = inode->i_sb;
+	int ret = 0;
+	int i, num_entries;
+	sector_t sector;
+	unsigned short chksum;
+	struct exfat_dentry *ep, *fep;
+	struct buffer_head *fbh, *bh;
+
+	fep = exfat_get_dentry(sb, p_dir, entry, &fbh, &sector);
+	if (!fep)
+		return -EIO;
+
+	num_entries = fep->dentry.file.num_ext + 1;
+	chksum = exfat_calc_chksum_2byte(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY);
+
+	for (i = 1; i < num_entries; i++) {
+		ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, NULL);
+		if (!ep) {
+			ret = -EIO;
+			goto release_fbh;
+		}
+		chksum = exfat_calc_chksum_2byte(ep, DENTRY_SIZE, chksum,
+				CS_DEFAULT);
+		brelse(bh);
+	}
+
+	fep->dentry.file.checksum = cpu_to_le16(chksum);
+	exfat_update_bh(sb, fbh, IS_DIRSYNC(inode));
+release_fbh:
+	brelse(fbh);
+	return ret;
+}
+
+int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir,
+		int entry, int num_entries, struct exfat_uni_name *p_uniname)
+{
+	struct super_block *sb = inode->i_sb;
+	int i;
+	sector_t sector;
+	unsigned short *uniname = p_uniname->name;
+	struct exfat_dentry *ep;
+	struct buffer_head *bh;
+	int sync = IS_DIRSYNC(inode);
+
+	ep = exfat_get_dentry(sb, p_dir, entry, &bh, &sector);
+	if (!ep)
+		return -EIO;
+
+	ep->dentry.file.num_ext = (unsigned char)(num_entries - 1);
+	exfat_update_bh(sb, bh, sync);
+	brelse(bh);
+
+	ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh, &sector);
+	if (!ep)
+		return -EIO;
+
+	ep->dentry.stream.name_len = p_uniname->name_len;
+	ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash);
+	exfat_update_bh(sb, bh, sync);
+	brelse(bh);
+
+	for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) {
+		ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, &sector);
+		if (!ep)
+			return -EIO;
+
+		exfat_init_name_entry(ep, uniname);
+		exfat_update_bh(sb, bh, sync);
+		brelse(bh);
+		uniname += EXFAT_FILE_NAME_LEN;
+	}
+
+	exfat_update_dir_chksum(inode, p_dir, entry);
+	return 0;
+}
+
+int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir,
+		int entry, int order, int num_entries)
+{
+	struct super_block *sb = inode->i_sb;
+	int i;
+	sector_t sector;
+	struct exfat_dentry *ep;
+	struct buffer_head *bh;
+
+	for (i = order; i < num_entries; i++) {
+		ep = exfat_get_dentry(sb, p_dir, entry + i, &bh, &sector);
+		if (!ep)
+			return -EIO;
+
+		exfat_set_entry_type(ep, TYPE_DELETED);
+		exfat_update_bh(sb, bh, IS_DIRSYNC(inode));
+		brelse(bh);
+	}
+
+	return 0;
+}
+
+int exfat_update_dir_chksum_with_entry_set(struct super_block *sb,
+		struct exfat_entry_set_cache *es, int sync)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct buffer_head *bh;
+	sector_t sec = es->sector;
+	unsigned int off = es->offset;
+	int chksum_type = CS_DIR_ENTRY, i, num_entries = es->num_entries;
+	unsigned int buf_off = (off - es->offset);
+	unsigned int remaining_byte_in_sector, copy_entries, clu;
+	unsigned short chksum = 0;
+
+	for (i = 0; i < num_entries; i++) {
+		chksum = exfat_calc_chksum_2byte(&es->entries[i], DENTRY_SIZE,
+			chksum, chksum_type);
+		chksum_type = CS_DEFAULT;
+	}
+
+	es->entries[0].dentry.file.checksum = cpu_to_le16(chksum);
+
+	while (num_entries) {
+		/* write per sector base */
+		remaining_byte_in_sector = (1 << sb->s_blocksize_bits) - off;
+		copy_entries = min_t(int,
+			EXFAT_B_TO_DEN(remaining_byte_in_sector),
+			num_entries);
+		bh = sb_bread(sb, sec);
+		if (!bh)
+			goto err_out;
+		memcpy(bh->b_data + off,
+			(unsigned char *)&es->entries[0] + buf_off,
+			EXFAT_DEN_TO_B(copy_entries));
+		exfat_update_bh(sb, bh, sync);
+		brelse(bh);
+		num_entries -= copy_entries;
+
+		if (num_entries) {
+			/* get next sector */
+			if (exfat_is_last_sector_in_cluster(sbi, sec)) {
+				clu = exfat_sector_to_cluster(sbi, sec);
+				if (es->alloc_flag == ALLOC_NO_FAT_CHAIN)
+					clu++;
+				else if (exfat_get_next_cluster(sb, &clu))
+					goto err_out;
+				sec = exfat_cluster_to_sector(sbi, clu);
+			} else {
+				sec++;
+			}
+			off = 0;
+			buf_off += EXFAT_DEN_TO_B(copy_entries);
+		}
+	}
+
+	return 0;
+err_out:
+	return -EIO;
+}
+
+static int exfat_walk_fat_chain(struct super_block *sb,
+		struct exfat_chain *p_dir, unsigned int byte_offset,
+		unsigned int *clu)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	unsigned int clu_offset;
+	unsigned int cur_clu;
+
+	clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi);
+	cur_clu = p_dir->dir;
+
+	if (p_dir->flags == ALLOC_NO_FAT_CHAIN) {
+		cur_clu += clu_offset;
+	} else {
+		while (clu_offset > 0) {
+			if (exfat_get_next_cluster(sb, &cur_clu))
+				return -EIO;
+			if (cur_clu == EXFAT_EOF_CLUSTER) {
+				exfat_fs_error(sb,
+					"invalid dentry access beyond EOF (clu : %u, eidx : %d)",
+					p_dir->dir,
+					EXFAT_B_TO_DEN(byte_offset));
+				return -EIO;
+			}
+			clu_offset--;
+		}
+	}
+
+	*clu = cur_clu;
+	return 0;
+}
+
+int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir,
+		int entry, sector_t *sector, int *offset)
+{
+	int ret;
+	unsigned int off, clu = 0;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	off = EXFAT_DEN_TO_B(entry);
+
+	ret = exfat_walk_fat_chain(sb, p_dir, off, &clu);
+	if (ret)
+		return ret;
+
+	/* byte offset in cluster */
+	off = EXFAT_CLU_OFFSET(off, sbi);
+
+	/* byte offset in sector    */
+	*offset = EXFAT_BLK_OFFSET(off, sb);
+
+	/* sector offset in cluster */
+	*sector = EXFAT_B_TO_BLK(off, sb);
+	*sector += exfat_cluster_to_sector(sbi, clu);
+	return 0;
+}
+
+#define EXFAT_MAX_RA_SIZE     (128*1024)
+static int exfat_dir_readahead(struct super_block *sb, sector_t sec)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct buffer_head *bh;
+	unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits;
+	unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits;
+	unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count);
+	unsigned int ra_count = min(adj_ra_count, max_ra_count);
+
+	/* Read-ahead is not required */
+	if (sbi->sect_per_clus == 1)
+		return 0;
+
+	if (sec < sbi->data_start_sector) {
+		exfat_msg(sb, KERN_ERR,
+			"requested sector is invalid(sect:%llu, root:%llu)",
+			(unsigned long long)sec, sbi->data_start_sector);
+		return -EIO;
+	}
+
+	/* Not sector aligned with ra_count, resize ra_count to page size */
+	if ((sec - sbi->data_start_sector) & (ra_count - 1))
+		ra_count = page_ra_count;
+
+	bh = sb_find_get_block(sb, sec);
+	if (!bh || !buffer_uptodate(bh)) {
+		unsigned int i;
+
+		for (i = 0; i < ra_count; i++)
+			sb_breadahead(sb, (sector_t)(sec + i));
+	}
+	brelse(bh);
+	return 0;
+}
+
+struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
+		struct exfat_chain *p_dir, int entry, struct buffer_head **bh,
+		sector_t *sector)
+{
+	unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE);
+	int off;
+	sector_t sec;
+
+	if (p_dir->dir == DIR_DELETED) {
+		exfat_msg(sb, KERN_ERR, "abnormal access to deleted dentry\n");
+		return NULL;
+	}
+
+	if (exfat_find_location(sb, p_dir, entry, &sec, &off))
+		return NULL;
+
+	if (p_dir->dir != EXFAT_FREE_CLUSTER &&
+			!(entry & (dentries_per_page - 1)))
+		exfat_dir_readahead(sb, sec);
+
+	*bh = sb_bread(sb, sec);
+	if (!*bh)
+		return NULL;
+
+	if (sector)
+		*sector = sec;
+	return (struct exfat_dentry *)((*bh)->b_data + off);
+}
+
+enum exfat_validate_dentry_mode {
+	ES_MODE_STARTED,
+	ES_MODE_GET_FILE_ENTRY,
+	ES_MODE_GET_STRM_ENTRY,
+	ES_MODE_GET_NAME_ENTRY,
+	ES_MODE_GET_CRITICAL_SEC_ENTRY,
+};
+
+static bool exfat_validate_entry(unsigned int type,
+		enum exfat_validate_dentry_mode *mode)
+{
+	if (type == TYPE_UNUSED || type == TYPE_DELETED)
+		return false;
+
+	switch (*mode) {
+	case ES_MODE_STARTED:
+		if  (type != TYPE_FILE && type != TYPE_DIR)
+			return false;
+		*mode = ES_MODE_GET_FILE_ENTRY;
+		return true;
+	case ES_MODE_GET_FILE_ENTRY:
+		if (type != TYPE_STREAM)
+			return false;
+		*mode = ES_MODE_GET_STRM_ENTRY;
+		return true;
+	case ES_MODE_GET_STRM_ENTRY:
+		if (type != TYPE_EXTEND)
+			return false;
+		*mode = ES_MODE_GET_NAME_ENTRY;
+		return true;
+	case ES_MODE_GET_NAME_ENTRY:
+		if (type == TYPE_STREAM)
+			return false;
+		if (type != TYPE_EXTEND) {
+			if (!(type & TYPE_CRITICAL_SEC))
+				return false;
+			*mode = ES_MODE_GET_CRITICAL_SEC_ENTRY;
+		}
+		return true;
+	case ES_MODE_GET_CRITICAL_SEC_ENTRY:
+		if (type == TYPE_EXTEND || type == TYPE_STREAM)
+			return false;
+		if ((type & TYPE_CRITICAL_SEC) != TYPE_CRITICAL_SEC)
+			return false;
+		return true;
+	default:
+		WARN_ON_ONCE(1);
+		return false;
+	}
+}
+
+/*
+ * Returns a set of dentries for a file or dir.
+ *
+ * Note that this is a copy (dump) of dentries so that user should
+ * call write_entry_set() to apply changes made in this entry set
+ * to the real device.
+ *
+ * in:
+ *   sb+p_dir+entry: indicates a file/dir
+ *   type:  specifies how many dentries should be included.
+ * out:
+ *   file_ep: will point the first dentry(= file dentry) on success
+ * return:
+ *   pointer of entry set on success,
+ *   NULL on failure.
+ */
+struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
+		struct exfat_chain *p_dir, int entry, unsigned int type,
+		struct exfat_dentry **file_ep)
+{
+	int ret;
+	unsigned int off, byte_offset, clu = 0;
+	unsigned int entry_type;
+	sector_t sec;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_entry_set_cache *es;
+	struct exfat_dentry *ep, *pos;
+	unsigned char num_entries;
+	enum exfat_validate_dentry_mode mode = ES_MODE_STARTED;
+	struct buffer_head *bh;
+
+	if (p_dir->dir == DIR_DELETED) {
+		exfat_msg(sb, KERN_ERR, "access to deleted dentry\n");
+		return NULL;
+	}
+
+	byte_offset = EXFAT_DEN_TO_B(entry);
+	ret = exfat_walk_fat_chain(sb, p_dir, byte_offset, &clu);
+	if (ret)
+		return NULL;
+
+	/* byte offset in cluster */
+	byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi);
+
+	/* byte offset in sector */
+	off = EXFAT_BLK_OFFSET(byte_offset, sb);
+
+	/* sector offset in cluster */
+	sec = EXFAT_B_TO_BLK(byte_offset, sb);
+	sec += exfat_cluster_to_sector(sbi, clu);
+
+	bh = sb_bread(sb, sec);
+	if (!bh)
+		return NULL;
+
+	ep = (struct exfat_dentry *)(bh->b_data + off);
+	entry_type = exfat_get_entry_type(ep);
+
+	if (entry_type != TYPE_FILE && entry_type != TYPE_DIR)
+		goto release_bh;
+
+	num_entries = type == ES_ALL_ENTRIES ?
+		ep->dentry.file.num_ext + 1 : type;
+	es = kmalloc(struct_size(es, entries, num_entries), GFP_KERNEL);
+	if (!es)
+		goto release_bh;
+
+	es->num_entries = num_entries;
+	es->sector = sec;
+	es->offset = off;
+	es->alloc_flag = p_dir->flags;
+
+	pos = &es->entries[0];
+
+	while (num_entries) {
+		if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
+			goto free_es;
+
+		/* copy dentry */
+		memcpy(pos, ep, sizeof(struct exfat_dentry));
+
+		if (--num_entries == 0)
+			break;
+
+		if (((off + DENTRY_SIZE) & (sb->s_blocksize - 1)) <
+		    (off & (sb->s_blocksize - 1))) {
+			/* get the next sector */
+			if (exfat_is_last_sector_in_cluster(sbi, sec)) {
+				if (es->alloc_flag == ALLOC_NO_FAT_CHAIN)
+					clu++;
+				else if (exfat_get_next_cluster(sb, &clu))
+					goto free_es;
+				sec = exfat_cluster_to_sector(sbi, clu);
+			} else {
+				sec++;
+			}
+
+			brelse(bh);
+			bh = sb_bread(sb, sec);
+			if (!bh)
+				goto free_es;
+			off = 0;
+			ep = (struct exfat_dentry *)bh->b_data;
+		} else {
+			ep++;
+			off += DENTRY_SIZE;
+		}
+		pos++;
+	}
+
+	if (file_ep)
+		*file_ep = &es->entries[0];
+	brelse(bh);
+	return es;
+
+free_es:
+	kfree(es);
+release_bh:
+	brelse(bh);
+	return NULL;
+}
+
+enum {
+	DIRENT_STEP_FILE,
+	DIRENT_STEP_STRM,
+	DIRENT_STEP_NAME,
+	DIRENT_STEP_SECD,
+};
+
+/*
+ * return values:
+ *   >= 0	: return dir entiry position with the name in dir
+ *   -EEXIST	: (root dir, ".") it is the root dir itself
+ *   -ENOENT	: entry with the name does not exist
+ *   -EIO	: I/O error
+ */
+int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
+		struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
+		int num_entries, unsigned int type)
+{
+	int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len;
+	int order, step, name_len = 0;
+	int dentries_per_clu, num_empty = 0;
+	unsigned int entry_type;
+	unsigned short *uniname = NULL;
+	struct exfat_chain clu;
+	struct exfat_hint *hint_stat = &ei->hint_stat;
+	struct exfat_hint_femp candi_empty;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	dentries_per_clu = sbi->dentries_per_clu;
+
+	exfat_chain_dup(&clu, p_dir);
+
+	if (hint_stat->eidx) {
+		clu.dir = hint_stat->clu;
+		dentry = hint_stat->eidx;
+		end_eidx = dentry;
+	}
+
+	candi_empty.eidx = EXFAT_HINT_NONE;
+rewind:
+	order = 0;
+	step = DIRENT_STEP_FILE;
+	while (clu.dir != EXFAT_EOF_CLUSTER) {
+		i = dentry & (dentries_per_clu - 1);
+		for (; i < dentries_per_clu; i++, dentry++) {
+			struct exfat_dentry *ep;
+			struct buffer_head *bh;
+
+			if (rewind && dentry == end_eidx)
+				goto not_found;
+
+			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
+			if (!ep)
+				return -EIO;
+
+			entry_type = exfat_get_entry_type(ep);
+
+			if (entry_type == TYPE_UNUSED ||
+			    entry_type == TYPE_DELETED) {
+				step = DIRENT_STEP_FILE;
+
+				num_empty++;
+				if (candi_empty.eidx == EXFAT_HINT_NONE &&
+						num_empty == 1) {
+					exfat_chain_set(&candi_empty.cur,
+						clu.dir, clu.size, clu.flags);
+				}
+
+				if (candi_empty.eidx == EXFAT_HINT_NONE &&
+						num_empty >= num_entries) {
+					candi_empty.eidx =
+						dentry - (num_empty - 1);
+					WARN_ON(candi_empty.eidx < 0);
+					candi_empty.count = num_empty;
+
+					if (ei->hint_femp.eidx ==
+							EXFAT_HINT_NONE ||
+						candi_empty.eidx <=
+							 ei->hint_femp.eidx) {
+						memcpy(&ei->hint_femp,
+							&candi_empty,
+							sizeof(candi_empty));
+					}
+				}
+
+				brelse(bh);
+				if (entry_type == TYPE_UNUSED)
+					goto not_found;
+				continue;
+			}
+
+			num_empty = 0;
+			candi_empty.eidx = EXFAT_HINT_NONE;
+
+			if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) {
+				step = DIRENT_STEP_FILE;
+				if (type == TYPE_ALL || type == entry_type) {
+					num_ext = ep->dentry.file.num_ext;
+					step = DIRENT_STEP_STRM;
+				}
+				brelse(bh);
+				continue;
+			}
+
+			if (entry_type == TYPE_STREAM) {
+				unsigned short name_hash;
+
+				if (step != DIRENT_STEP_STRM) {
+					step = DIRENT_STEP_FILE;
+					brelse(bh);
+					continue;
+				}
+				step = DIRENT_STEP_FILE;
+				name_hash = le16_to_cpu(
+						ep->dentry.stream.name_hash);
+				if (p_uniname->name_hash == name_hash &&
+				    p_uniname->name_len ==
+						ep->dentry.stream.name_len) {
+					step = DIRENT_STEP_NAME;
+					order = 1;
+					name_len = 0;
+				}
+				brelse(bh);
+				continue;
+			}
+
+			brelse(bh);
+			if (entry_type == TYPE_EXTEND) {
+				unsigned short entry_uniname[16], unichar;
+
+				if (step != DIRENT_STEP_NAME) {
+					step = DIRENT_STEP_FILE;
+					continue;
+				}
+
+				if (++order == 2)
+					uniname = p_uniname->name;
+				else
+					uniname += EXFAT_FILE_NAME_LEN;
+
+				len = exfat_extract_uni_name(ep, entry_uniname);
+				name_len += len;
+
+				unichar = *(uniname+len);
+				*(uniname+len) = 0x0;
+
+				if (exfat_uniname_ncmp(sb, uniname,
+					entry_uniname, len)) {
+					step = DIRENT_STEP_FILE;
+				} else if (p_uniname->name_len == name_len) {
+					if (order == num_ext)
+						goto found;
+					step = DIRENT_STEP_SECD;
+				}
+
+				*(uniname+len) = unichar;
+				continue;
+			}
+
+			if (entry_type &
+					(TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) {
+				if (step == DIRENT_STEP_SECD) {
+					if (++order == num_ext)
+						goto found;
+					continue;
+				}
+			}
+			step = DIRENT_STEP_FILE;
+		}
+
+		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
+			if (--clu.size > 0)
+				clu.dir++;
+			else
+				clu.dir = EXFAT_EOF_CLUSTER;
+		} else {
+			if (exfat_get_next_cluster(sb, &clu.dir))
+				return -EIO;
+		}
+	}
+
+not_found:
+	/*
+	 * We started at not 0 index,so we should try to find target
+	 * from 0 index to the index we started at.
+	 */
+	if (!rewind && end_eidx) {
+		rewind = 1;
+		dentry = 0;
+		clu.dir = p_dir->dir;
+		/* reset empty hint */
+		num_empty = 0;
+		candi_empty.eidx = EXFAT_HINT_NONE;
+		goto rewind;
+	}
+
+	/* initialized hint_stat */
+	hint_stat->clu = p_dir->dir;
+	hint_stat->eidx = 0;
+	return -ENOENT;
+
+found:
+	/* next dentry we'll find is out of this cluster */
+	if (!((dentry + 1) & (dentries_per_clu - 1))) {
+		int ret = 0;
+
+		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
+			if (--clu.size > 0)
+				clu.dir++;
+			else
+				clu.dir = EXFAT_EOF_CLUSTER;
+		} else {
+			ret = exfat_get_next_cluster(sb, &clu.dir);
+		}
+
+		if (ret || clu.dir != EXFAT_EOF_CLUSTER) {
+			/* just initialized hint_stat */
+			hint_stat->clu = p_dir->dir;
+			hint_stat->eidx = 0;
+			return (dentry - num_ext);
+		}
+	}
+
+	hint_stat->clu = clu.dir;
+	hint_stat->eidx = dentry + 1;
+	return dentry - num_ext;
+}
+
+int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir,
+		int entry, struct exfat_dentry *ep)
+{
+	int i, count = 0;
+	unsigned int type;
+	struct exfat_dentry *ext_ep;
+	struct buffer_head *bh;
+
+	for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) {
+		ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh, NULL);
+		if (!ext_ep)
+			return -EIO;
+
+		type = exfat_get_entry_type(ext_ep);
+		brelse(bh);
+		if (type == TYPE_EXTEND || type == TYPE_STREAM)
+			count++;
+		else
+			break;
+	}
+	return count;
+}
+
+int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir)
+{
+	int i, count = 0;
+	int dentries_per_clu;
+	unsigned int entry_type;
+	struct exfat_chain clu;
+	struct exfat_dentry *ep;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct buffer_head *bh;
+
+	dentries_per_clu = sbi->dentries_per_clu;
+
+	exfat_chain_dup(&clu, p_dir);
+
+	while (clu.dir != EXFAT_EOF_CLUSTER) {
+		for (i = 0; i < dentries_per_clu; i++) {
+			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
+			if (!ep)
+				return -EIO;
+			entry_type = exfat_get_entry_type(ep);
+			brelse(bh);
+
+			if (entry_type == TYPE_UNUSED)
+				return count;
+			if (entry_type != TYPE_DIR)
+				continue;
+			count++;
+		}
+
+		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
+			if (--clu.size > 0)
+				clu.dir++;
+			else
+				clu.dir = EXFAT_EOF_CLUSTER;
+		} else {
+			if (exfat_get_next_cluster(sb, &(clu.dir)))
+				return -EIO;
+		}
+	}
+
+	return count;
+}

fs/exfat/exfat_fs.h

···
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef _EXFAT_FS_H
+#define _EXFAT_FS_H
+
+#include <linux/fs.h>
+#include <linux/ratelimit.h>
+#include <linux/nls.h>
+
+#define EXFAT_SUPER_MAGIC       0x2011BAB0UL
+#define EXFAT_ROOT_INO		1
+
+#define EXFAT_SB_DIRTY		0
+
+#define EXFAT_CLUSTERS_UNTRACKED (~0u)
+
+/*
+ * exfat error flags
+ */
+enum exfat_error_mode {
+	EXFAT_ERRORS_CONT,	/* ignore error and continue */
+	EXFAT_ERRORS_PANIC,	/* panic on error */
+	EXFAT_ERRORS_RO,	/* remount r/o on error */
+};
+
+/*
+ * exfat nls lossy flag
+ */
+enum {
+	NLS_NAME_NO_LOSSY,	/* no lossy */
+	NLS_NAME_LOSSY,		/* just detected incorrect filename(s) */
+	NLS_NAME_OVERLEN,	/* the length is over than its limit */
+};
+
+#define EXFAT_HASH_BITS		8
+#define EXFAT_HASH_SIZE		(1UL << EXFAT_HASH_BITS)
+
+/*
+ * Type Definitions
+ */
+#define ES_2_ENTRIES		2
+#define ES_ALL_ENTRIES		0
+
+#define DIR_DELETED		0xFFFF0321
+
+/* type values */
+#define TYPE_UNUSED		0x0000
+#define TYPE_DELETED		0x0001
+#define TYPE_INVALID		0x0002
+#define TYPE_CRITICAL_PRI	0x0100
+#define TYPE_BITMAP		0x0101
+#define TYPE_UPCASE		0x0102
+#define TYPE_VOLUME		0x0103
+#define TYPE_DIR		0x0104
+#define TYPE_FILE		0x011F
+#define TYPE_CRITICAL_SEC	0x0200
+#define TYPE_STREAM		0x0201
+#define TYPE_EXTEND		0x0202
+#define TYPE_ACL		0x0203
+#define TYPE_BENIGN_PRI		0x0400
+#define TYPE_GUID		0x0401
+#define TYPE_PADDING		0x0402
+#define TYPE_ACLTAB		0x0403
+#define TYPE_BENIGN_SEC		0x0800
+#define TYPE_ALL		0x0FFF
+
+#define MAX_CHARSET_SIZE	6 /* max size of multi-byte character */
+#define MAX_NAME_LENGTH		255 /* max len of file name excluding NULL */
+#define MAX_VFSNAME_BUF_SIZE	((MAX_NAME_LENGTH + 1) * MAX_CHARSET_SIZE)
+
+#define FAT_CACHE_SIZE		128
+#define FAT_CACHE_HASH_SIZE	64
+#define BUF_CACHE_SIZE		256
+#define BUF_CACHE_HASH_SIZE	64
+
+#define EXFAT_HINT_NONE		-1
+#define EXFAT_MIN_SUBDIR	2
+
+/*
+ * helpers for cluster size to byte conversion.
+ */
+#define EXFAT_CLU_TO_B(b, sbi)		((b) << (sbi)->cluster_size_bits)
+#define EXFAT_B_TO_CLU(b, sbi)		((b) >> (sbi)->cluster_size_bits)
+#define EXFAT_B_TO_CLU_ROUND_UP(b, sbi)	\
+	(((b - 1) >> (sbi)->cluster_size_bits) + 1)
+#define EXFAT_CLU_OFFSET(off, sbi)	((off) & ((sbi)->cluster_size - 1))
+
+/*
+ * helpers for block size to byte conversion.
+ */
+#define EXFAT_BLK_TO_B(b, sb)		((b) << (sb)->s_blocksize_bits)
+#define EXFAT_B_TO_BLK(b, sb)		((b) >> (sb)->s_blocksize_bits)
+#define EXFAT_B_TO_BLK_ROUND_UP(b, sb)	\
+	(((b - 1) >> (sb)->s_blocksize_bits) + 1)
+#define EXFAT_BLK_OFFSET(off, sb)	((off) & ((sb)->s_blocksize - 1))
+
+/*
+ * helpers for block size to dentry size conversion.
+ */
+#define EXFAT_B_TO_DEN_IDX(b, sbi)	\
+	((b) << ((sbi)->cluster_size_bits - DENTRY_SIZE_BITS))
+#define EXFAT_B_TO_DEN(b)		((b) >> DENTRY_SIZE_BITS)
+#define EXFAT_DEN_TO_B(b)		((b) << DENTRY_SIZE_BITS)
+
+/*
+ * helpers for fat entry.
+ */
+#define FAT_ENT_SIZE (4)
+#define FAT_ENT_SIZE_BITS (2)
+#define FAT_ENT_OFFSET_SECTOR(sb, loc) (EXFAT_SB(sb)->FAT1_start_sector + \
+	(((u64)loc << FAT_ENT_SIZE_BITS) >> sb->s_blocksize_bits))
+#define FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc)	\
+	((loc << FAT_ENT_SIZE_BITS) & (sb->s_blocksize - 1))
+
+/*
+ * helpers for bitmap.
+ */
+#define CLUSTER_TO_BITMAP_ENT(clu) ((clu) - EXFAT_RESERVED_CLUSTERS)
+#define BITMAP_ENT_TO_CLUSTER(ent) ((ent) + EXFAT_RESERVED_CLUSTERS)
+#define BITS_PER_SECTOR(sb) ((sb)->s_blocksize * BITS_PER_BYTE)
+#define BITS_PER_SECTOR_MASK(sb) (BITS_PER_SECTOR(sb) - 1)
+#define BITMAP_OFFSET_SECTOR_INDEX(sb, ent) \
+	((ent / BITS_PER_BYTE) >> (sb)->s_blocksize_bits)
+#define BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent) (ent & BITS_PER_SECTOR_MASK(sb))
+#define BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent) \
+	((ent / BITS_PER_BYTE) & ((sb)->s_blocksize - 1))
+#define BITS_PER_BYTE_MASK	0x7
+#define IGNORED_BITS_REMAINED(clu, clu_base) ((1 << ((clu) - (clu_base))) - 1)
+
+struct exfat_dentry_namebuf {
+	char *lfn;
+	int lfnbuf_len; /* usally MAX_UNINAME_BUF_SIZE */
+};
+
+/* unicode name structure */
+struct exfat_uni_name {
+	/* +3 for null and for converting */
+	unsigned short name[MAX_NAME_LENGTH + 3];
+	unsigned short name_hash;
+	unsigned char name_len;
+};
+
+/* directory structure */
+struct exfat_chain {
+	unsigned int dir;
+	unsigned int size;
+	unsigned char flags;
+};
+
+/* first empty entry hint information */
+struct exfat_hint_femp {
+	/* entry index of a directory */
+	int eidx;
+	/* count of continuous empty entry */
+	int count;
+	/* the cluster that first empty slot exists in */
+	struct exfat_chain cur;
+};
+
+/* hint structure */
+struct exfat_hint {
+	unsigned int clu;
+	union {
+		unsigned int off; /* cluster offset */
+		int eidx; /* entry index */
+	};
+};
+
+struct exfat_entry_set_cache {
+	/* sector number that contains file_entry */
+	sector_t sector;
+	/* byte offset in the sector */
+	unsigned int offset;
+	/* flag in stream entry. 01 for cluster chain, 03 for contig. */
+	int alloc_flag;
+	unsigned int num_entries;
+	struct exfat_dentry entries[];
+};
+
+struct exfat_dir_entry {
+	struct exfat_chain dir;
+	int entry;
+	unsigned int type;
+	unsigned int start_clu;
+	unsigned char flags;
+	unsigned short attr;
+	loff_t size;
+	unsigned int num_subdirs;
+	struct timespec64 atime;
+	struct timespec64 mtime;
+	struct timespec64 crtime;
+	struct exfat_dentry_namebuf namebuf;
+};
+
+/*
+ * exfat mount in-memory data
+ */
+struct exfat_mount_options {
+	kuid_t fs_uid;
+	kgid_t fs_gid;
+	unsigned short fs_fmask;
+	unsigned short fs_dmask;
+	/* permission for setting the [am]time */
+	unsigned short allow_utime;
+	/* charset for filename input/display */
+	char *iocharset;
+	/* on error: continue, panic, remount-ro */
+	enum exfat_error_mode errors;
+	unsigned utf8:1, /* Use of UTF-8 character set */
+		 discard:1; /* Issue discard requests on deletions */
+	int time_offset; /* Offset of timestamps from UTC (in minutes) */
+};
+
+/*
+ * EXFAT file system superblock in-memory data
+ */
+struct exfat_sb_info {
+	unsigned long long num_sectors; /* num of sectors in volume */
+	unsigned int num_clusters; /* num of clusters in volume */
+	unsigned int cluster_size; /* cluster size in bytes */
+	unsigned int cluster_size_bits;
+	unsigned int sect_per_clus; /* cluster size in sectors */
+	unsigned int sect_per_clus_bits;
+	unsigned long long FAT1_start_sector; /* FAT1 start sector */
+	unsigned long long FAT2_start_sector; /* FAT2 start sector */
+	unsigned long long data_start_sector; /* data area start sector */
+	unsigned int num_FAT_sectors; /* num of FAT sectors */
+	unsigned int root_dir; /* root dir cluster */
+	unsigned int dentries_per_clu; /* num of dentries per cluster */
+	unsigned int vol_flag; /* volume dirty flag */
+	struct buffer_head *pbr_bh; /* buffer_head of PBR sector */
+
+	unsigned int map_clu; /* allocation bitmap start cluster */
+	unsigned int map_sectors; /* num of allocation bitmap sectors */
+	struct buffer_head **vol_amap; /* allocation bitmap */
+
+	unsigned short *vol_utbl; /* upcase table */
+
+	unsigned int clu_srch_ptr; /* cluster search pointer */
+	unsigned int used_clusters; /* number of used clusters */
+
+	unsigned long s_state;
+	struct mutex s_lock; /* superblock lock */
+	struct exfat_mount_options options;
+	struct nls_table *nls_io; /* Charset used for input and display */
+	struct ratelimit_state ratelimit;
+
+	spinlock_t inode_hash_lock;
+	struct hlist_head inode_hashtable[EXFAT_HASH_SIZE];
+
+	struct rcu_head rcu;
+};
+
+/*
+ * EXFAT file system inode in-memory data
+ */
+struct exfat_inode_info {
+	struct exfat_chain dir;
+	int entry;
+	unsigned int type;
+	unsigned short attr;
+	unsigned int start_clu;
+	unsigned char flags;
+	/*
+	 * the copy of low 32bit of i_version to check
+	 * the validation of hint_stat.
+	 */
+	unsigned int version;
+	/* file offset or dentry index for readdir */
+	loff_t rwoffset;
+
+	/* hint for cluster last accessed */
+	struct exfat_hint hint_bmap;
+	/* hint for entry index we try to lookup next time */
+	struct exfat_hint hint_stat;
+	/* hint for first empty entry */
+	struct exfat_hint_femp hint_femp;
+
+	spinlock_t cache_lru_lock;
+	struct list_head cache_lru;
+	int nr_caches;
+	/* for avoiding the race between alloc and free */
+	unsigned int cache_valid_id;
+
+	/*
+	 * NOTE: i_size_ondisk is 64bits, so must hold ->inode_lock to access.
+	 * physically allocated size.
+	 */
+	loff_t i_size_ondisk;
+	/* block-aligned i_size (used in cont_write_begin) */
+	loff_t i_size_aligned;
+	/* on-disk position of directory entry or 0 */
+	loff_t i_pos;
+	/* hash by i_location */
+	struct hlist_node i_hash_fat;
+	/* protect bmap against truncate */
+	struct rw_semaphore truncate_lock;
+	struct inode vfs_inode;
+	/* File creation time */
+	struct timespec64 i_crtime;
+};
+
+static inline struct exfat_sb_info *EXFAT_SB(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+static inline struct exfat_inode_info *EXFAT_I(struct inode *inode)
+{
+	return container_of(inode, struct exfat_inode_info, vfs_inode);
+}
+
+/*
+ * If ->i_mode can't hold 0222 (i.e. ATTR_RO), we use ->i_attrs to
+ * save ATTR_RO instead of ->i_mode.
+ *
+ * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
+ * bit, it's just used as flag for app.
+ */
+static inline int exfat_mode_can_hold_ro(struct inode *inode)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
+
+	if (S_ISDIR(inode->i_mode))
+		return 0;
+
+	if ((~sbi->options.fs_fmask) & 0222)
+		return 1;
+	return 0;
+}
+
+/* Convert attribute bits and a mask to the UNIX mode. */
+static inline mode_t exfat_make_mode(struct exfat_sb_info *sbi,
+		unsigned short attr, mode_t mode)
+{
+	if ((attr & ATTR_READONLY) && !(attr & ATTR_SUBDIR))
+		mode &= ~0222;
+
+	if (attr & ATTR_SUBDIR)
+		return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
+
+	return (mode & ~sbi->options.fs_fmask) | S_IFREG;
+}
+
+/* Return the FAT attribute byte for this inode */
+static inline unsigned short exfat_make_attr(struct inode *inode)
+{
+	unsigned short attr = EXFAT_I(inode)->attr;
+
+	if (S_ISDIR(inode->i_mode))
+		attr |= ATTR_SUBDIR;
+	if (exfat_mode_can_hold_ro(inode) && !(inode->i_mode & 0222))
+		attr |= ATTR_READONLY;
+	return attr;
+}
+
+static inline void exfat_save_attr(struct inode *inode, unsigned short attr)
+{
+	if (exfat_mode_can_hold_ro(inode))
+		EXFAT_I(inode)->attr = attr & (ATTR_RWMASK | ATTR_READONLY);
+	else
+		EXFAT_I(inode)->attr = attr & ATTR_RWMASK;
+}
+
+static inline bool exfat_is_last_sector_in_cluster(struct exfat_sb_info *sbi,
+		sector_t sec)
+{
+	return ((sec - sbi->data_start_sector + 1) &
+		((1 << sbi->sect_per_clus_bits) - 1)) == 0;
+}
+
+static inline sector_t exfat_cluster_to_sector(struct exfat_sb_info *sbi,
+		unsigned int clus)
+{
+	return ((clus - EXFAT_RESERVED_CLUSTERS) << sbi->sect_per_clus_bits) +
+		sbi->data_start_sector;
+}
+
+static inline int exfat_sector_to_cluster(struct exfat_sb_info *sbi,
+		sector_t sec)
+{
+	return ((sec - sbi->data_start_sector) >> sbi->sect_per_clus_bits) +
+		EXFAT_RESERVED_CLUSTERS;
+}
+
+/* super.c */
+int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flag);
+
+/* fatent.c */
+#define exfat_get_next_cluster(sb, pclu) exfat_ent_get(sb, *(pclu), pclu)
+
+int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
+		struct exfat_chain *p_chain);
+int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain);
+int exfat_ent_get(struct super_block *sb, unsigned int loc,
+		unsigned int *content);
+int exfat_ent_set(struct super_block *sb, unsigned int loc,
+		unsigned int content);
+int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir,
+		int entry, struct exfat_dentry *p_entry);
+int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain,
+		unsigned int len);
+int exfat_zeroed_cluster(struct inode *dir, unsigned int clu);
+int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,
+		unsigned int *ret_clu);
+int exfat_count_num_clusters(struct super_block *sb,
+		struct exfat_chain *p_chain, unsigned int *ret_count);
+
+/* balloc.c */
+int exfat_load_bitmap(struct super_block *sb);
+void exfat_free_bitmap(struct exfat_sb_info *sbi);
+int exfat_set_bitmap(struct inode *inode, unsigned int clu);
+void exfat_clear_bitmap(struct inode *inode, unsigned int clu);
+unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu);
+int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count);
+
+/* file.c */
+extern const struct file_operations exfat_file_operations;
+int __exfat_truncate(struct inode *inode, loff_t new_size);
+void exfat_truncate(struct inode *inode, loff_t size);
+int exfat_setattr(struct dentry *dentry, struct iattr *attr);
+int exfat_getattr(const struct path *path, struct kstat *stat,
+		unsigned int request_mask, unsigned int query_flags);
+
+/* namei.c */
+extern const struct dentry_operations exfat_dentry_ops;
+extern const struct dentry_operations exfat_utf8_dentry_ops;
+
+/* cache.c */
+int exfat_cache_init(void);
+void exfat_cache_shutdown(void);
+void exfat_cache_init_inode(struct inode *inode);
+void exfat_cache_inval_inode(struct inode *inode);
+int exfat_get_cluster(struct inode *inode, unsigned int cluster,
+		unsigned int *fclus, unsigned int *dclus,
+		unsigned int *last_dclus, int allow_eof);
+
+/* dir.c */
+extern const struct inode_operations exfat_dir_inode_operations;
+extern const struct file_operations exfat_dir_operations;
+unsigned int exfat_get_entry_type(struct exfat_dentry *p_entry);
+int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir,
+		int entry, unsigned int type, unsigned int start_clu,
+		unsigned long long size);
+int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir,
+		int entry, int num_entries, struct exfat_uni_name *p_uniname);
+int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir,
+		int entry, int order, int num_entries);
+int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
+		int entry);
+int exfat_update_dir_chksum_with_entry_set(struct super_block *sb,
+		struct exfat_entry_set_cache *es, int sync);
+int exfat_calc_num_entries(struct exfat_uni_name *p_uniname);
+int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
+		struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
+		int num_entries, unsigned int type);
+int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu);
+int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir,
+		int entry, sector_t *sector, int *offset);
+struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
+		struct exfat_chain *p_dir, int entry, struct buffer_head **bh,
+		sector_t *sector);
+struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
+		struct exfat_chain *p_dir, int entry, unsigned int type,
+		struct exfat_dentry **file_ep);
+int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);
+
+/* inode.c */
+extern const struct inode_operations exfat_file_inode_operations;
+void exfat_sync_inode(struct inode *inode);
+struct inode *exfat_build_inode(struct super_block *sb,
+		struct exfat_dir_entry *info, loff_t i_pos);
+void exfat_hash_inode(struct inode *inode, loff_t i_pos);
+void exfat_unhash_inode(struct inode *inode);
+struct inode *exfat_iget(struct super_block *sb, loff_t i_pos);
+int exfat_write_inode(struct inode *inode, struct writeback_control *wbc);
+void exfat_evict_inode(struct inode *inode);
+int exfat_block_truncate_page(struct inode *inode, loff_t from);
+
+/* exfat/nls.c */
+unsigned short exfat_toupper(struct super_block *sb, unsigned short a);
+int exfat_uniname_ncmp(struct super_block *sb, unsigned short *a,
+		unsigned short *b, unsigned int len);
+int exfat_utf16_to_nls(struct super_block *sb,
+		struct exfat_uni_name *uniname, unsigned char *p_cstring,
+		int len);
+int exfat_nls_to_utf16(struct super_block *sb,
+		const unsigned char *p_cstring, const int len,
+		struct exfat_uni_name *uniname, int *p_lossy);
+int exfat_create_upcase_table(struct super_block *sb);
+void exfat_free_upcase_table(struct exfat_sb_info *sbi);
+unsigned short exfat_high_surrogate(unicode_t u);
+unsigned short exfat_low_surrogate(unicode_t u);
+
+/* exfat/misc.c */
+void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
+		__printf(3, 4) __cold;
+#define exfat_fs_error(sb, fmt, args...)          \
+		__exfat_fs_error(sb, 1, fmt, ## args)
+#define exfat_fs_error_ratelimit(sb, fmt, args...) \
+		__exfat_fs_error(sb, __ratelimit(&EXFAT_SB(sb)->ratelimit), \
+		fmt, ## args)
+void exfat_msg(struct super_block *sb, const char *lv, const char *fmt, ...)
+		__printf(3, 4) __cold;
+void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
+		u8 tz, __le16 time, __le16 date, u8 time_ms);
+void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
+		u8 *tz, __le16 *time, __le16 *date, u8 *time_ms);
+unsigned short exfat_calc_chksum_2byte(void *data, int len,
+		unsigned short chksum, int type);
+void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync);
+void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
+		unsigned int size, unsigned char flags);
+void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec);
+
+#endif /* !_EXFAT_FS_H */

fs/exfat/exfat_raw.h

···
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef _EXFAT_RAW_H
+#define _EXFAT_RAW_H
+
+#include <linux/types.h>
+
+#define PBR_SIGNATURE		0xAA55
+
+#define EXFAT_MAX_FILE_LEN	255
+
+#define VOL_CLEAN		0x0000
+#define VOL_DIRTY		0x0002
+
+#define EXFAT_EOF_CLUSTER	0xFFFFFFFFu
+#define EXFAT_BAD_CLUSTER	0xFFFFFFF7u
+#define EXFAT_FREE_CLUSTER	0
+/* Cluster 0, 1 are reserved, the first cluster is 2 in the cluster heap. */
+#define EXFAT_RESERVED_CLUSTERS	2
+#define EXFAT_FIRST_CLUSTER	2
+#define EXFAT_DATA_CLUSTER_COUNT(sbi)	\
+	((sbi)->num_clusters - EXFAT_RESERVED_CLUSTERS)
+
+/* AllocationPossible and NoFatChain field in GeneralSecondaryFlags Field */
+#define ALLOC_FAT_CHAIN		0x01
+#define ALLOC_NO_FAT_CHAIN	0x03
+
+#define DENTRY_SIZE		32 /* directory entry size */
+#define DENTRY_SIZE_BITS	5
+/* exFAT allows 8388608(256MB) directory entries */
+#define MAX_EXFAT_DENTRIES	8388608
+
+/* dentry types */
+#define EXFAT_UNUSED		0x00	/* end of directory */
+#define EXFAT_DELETE		(~0x80)
+#define IS_EXFAT_DELETED(x)	((x) < 0x80) /* deleted file (0x01~0x7F) */
+#define EXFAT_INVAL		0x80	/* invalid value */
+#define EXFAT_BITMAP		0x81	/* allocation bitmap */
+#define EXFAT_UPCASE		0x82	/* upcase table */
+#define EXFAT_VOLUME		0x83	/* volume label */
+#define EXFAT_FILE		0x85	/* file or dir */
+#define EXFAT_GUID		0xA0
+#define EXFAT_PADDING		0xA1
+#define EXFAT_ACLTAB		0xA2
+#define EXFAT_STREAM		0xC0	/* stream entry */
+#define EXFAT_NAME		0xC1	/* file name entry */
+#define EXFAT_ACL		0xC2	/* stream entry */
+
+#define IS_EXFAT_CRITICAL_PRI(x)	(x < 0xA0)
+#define IS_EXFAT_BENIGN_PRI(x)		(x < 0xC0)
+#define IS_EXFAT_CRITICAL_SEC(x)	(x < 0xE0)
+
+/* checksum types */
+#define CS_DIR_ENTRY		0
+#define CS_PBR_SECTOR		1
+#define CS_DEFAULT		2
+
+/* file attributes */
+#define ATTR_READONLY		0x0001
+#define ATTR_HIDDEN		0x0002
+#define ATTR_SYSTEM		0x0004
+#define ATTR_VOLUME		0x0008
+#define ATTR_SUBDIR		0x0010
+#define ATTR_ARCHIVE		0x0020
+
+#define ATTR_RWMASK		(ATTR_HIDDEN | ATTR_SYSTEM | ATTR_VOLUME | \
+				 ATTR_SUBDIR | ATTR_ARCHIVE)
+
+#define PBR64_JUMP_BOOT_LEN		3
+#define PBR64_OEM_NAME_LEN		8
+#define PBR64_RESERVED_LEN		53
+
+#define EXFAT_FILE_NAME_LEN		15
+
+/* EXFAT BIOS parameter block (64 bytes) */
+struct bpb64 {
+	__u8 jmp_boot[PBR64_JUMP_BOOT_LEN];
+	__u8 oem_name[PBR64_OEM_NAME_LEN];
+	__u8 res_zero[PBR64_RESERVED_LEN];
+} __packed;
+
+/* EXFAT EXTEND BIOS parameter block (56 bytes) */
+struct bsx64 {
+	__le64 vol_offset;
+	__le64 vol_length;
+	__le32 fat_offset;
+	__le32 fat_length;
+	__le32 clu_offset;
+	__le32 clu_count;
+	__le32 root_cluster;
+	__le32 vol_serial;
+	__u8 fs_version[2];
+	__le16 vol_flags;
+	__u8 sect_size_bits;
+	__u8 sect_per_clus_bits;
+	__u8 num_fats;
+	__u8 phy_drv_no;
+	__u8 perc_in_use;
+	__u8 reserved2[7];
+} __packed;
+
+/* EXFAT PBR[BPB+BSX] (120 bytes) */
+struct pbr64 {
+	struct bpb64 bpb;
+	struct bsx64 bsx;
+} __packed;
+
+/* Common PBR[Partition Boot Record] (512 bytes) */
+struct pbr {
+	union {
+		__u8 raw[64];
+		struct bpb64 f64;
+	} bpb;
+	union {
+		__u8 raw[56];
+		struct bsx64 f64;
+	} bsx;
+	__u8 boot_code[390];
+	__le16 signature;
+} __packed;
+
+struct exfat_dentry {
+	__u8 type;
+	union {
+		struct {
+			__u8 num_ext;
+			__le16 checksum;
+			__le16 attr;
+			__le16 reserved1;
+			__le16 create_time;
+			__le16 create_date;
+			__le16 modify_time;
+			__le16 modify_date;
+			__le16 access_time;
+			__le16 access_date;
+			__u8 create_time_ms;
+			__u8 modify_time_ms;
+			__u8 create_tz;
+			__u8 modify_tz;
+			__u8 access_tz;
+			__u8 reserved2[7];
+		} __packed file; /* file directory entry */
+		struct {
+			__u8 flags;
+			__u8 reserved1;
+			__u8 name_len;
+			__le16 name_hash;
+			__le16 reserved2;
+			__le64 valid_size;
+			__le32 reserved3;
+			__le32 start_clu;
+			__le64 size;
+		} __packed stream; /* stream extension directory entry */
+		struct {
+			__u8 flags;
+			__le16 unicode_0_14[EXFAT_FILE_NAME_LEN];
+		} __packed name; /* file name directory entry */
+		struct {
+			__u8 flags;
+			__u8 reserved[18];
+			__le32 start_clu;
+			__le64 size;
+		} __packed bitmap; /* allocation bitmap directory entry */
+		struct {
+			__u8 reserved1[3];
+			__le32 checksum;
+			__u8 reserved2[12];
+			__le32 start_clu;
+			__le64 size;
+		} __packed upcase; /* up-case table directory entry */
+	} __packed dentry;
+} __packed;
+
+#define EXFAT_TZ_VALID		(1 << 7)
+
+/* Jan 1 GMT 00:00:00 1980 */
+#define EXFAT_MIN_TIMESTAMP_SECS    315532800LL
+/* Dec 31 GMT 23:59:59 2107 */
+#define EXFAT_MAX_TIMESTAMP_SECS    4354819199LL
+
+#endif /* !_EXFAT_RAW_H */

fs/exfat/fatent.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+#include <linux/buffer_head.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+
+static int exfat_mirror_bh(struct super_block *sb, sector_t sec,
+		struct buffer_head *bh)
+{
+	struct buffer_head *c_bh;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	sector_t sec2;
+	int err = 0;
+
+	if (sbi->FAT2_start_sector != sbi->FAT1_start_sector) {
+		sec2 = sec - sbi->FAT1_start_sector + sbi->FAT2_start_sector;
+		c_bh = sb_getblk(sb, sec2);
+		if (!c_bh)
+			return -ENOMEM;
+		memcpy(c_bh->b_data, bh->b_data, sb->s_blocksize);
+		set_buffer_uptodate(c_bh);
+		mark_buffer_dirty(c_bh);
+		if (sb->s_flags & SB_SYNCHRONOUS)
+			err = sync_dirty_buffer(c_bh);
+		brelse(c_bh);
+	}
+
+	return err;
+}
+
+static int __exfat_ent_get(struct super_block *sb, unsigned int loc,
+		unsigned int *content)
+{
+	unsigned int off;
+	sector_t sec;
+	struct buffer_head *bh;
+
+	sec = FAT_ENT_OFFSET_SECTOR(sb, loc);
+	off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc);
+
+	bh = sb_bread(sb, sec);
+	if (!bh)
+		return -EIO;
+
+	*content = le32_to_cpu(*(__le32 *)(&bh->b_data[off]));
+
+	/* remap reserved clusters to simplify code */
+	if (*content > EXFAT_BAD_CLUSTER)
+		*content = EXFAT_EOF_CLUSTER;
+
+	brelse(bh);
+	return 0;
+}
+
+int exfat_ent_set(struct super_block *sb, unsigned int loc,
+		unsigned int content)
+{
+	unsigned int off;
+	sector_t sec;
+	__le32 *fat_entry;
+	struct buffer_head *bh;
+
+	sec = FAT_ENT_OFFSET_SECTOR(sb, loc);
+	off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc);
+
+	bh = sb_bread(sb, sec);
+	if (!bh)
+		return -EIO;
+
+	fat_entry = (__le32 *)&(bh->b_data[off]);
+	*fat_entry = cpu_to_le32(content);
+	exfat_update_bh(sb, bh, sb->s_flags & SB_SYNCHRONOUS);
+	exfat_mirror_bh(sb, sec, bh);
+	brelse(bh);
+	return 0;
+}
+
+static inline bool is_valid_cluster(struct exfat_sb_info *sbi,
+		unsigned int clus)
+{
+	if (clus < EXFAT_FIRST_CLUSTER || sbi->num_clusters <= clus)
+		return false;
+	return true;
+}
+
+int exfat_ent_get(struct super_block *sb, unsigned int loc,
+		unsigned int *content)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	int err;
+
+	if (!is_valid_cluster(sbi, loc)) {
+		exfat_fs_error(sb, "invalid access to FAT (entry 0x%08x)",
+			loc);
+		return -EIO;
+	}
+
+	err = __exfat_ent_get(sb, loc, content);
+	if (err) {
+		exfat_fs_error(sb,
+			"failed to access to FAT (entry 0x%08x, err:%d)",
+			loc, err);
+		return err;
+	}
+
+	if (*content == EXFAT_FREE_CLUSTER) {
+		exfat_fs_error(sb,
+			"invalid access to FAT free cluster (entry 0x%08x)",
+			loc);
+		return -EIO;
+	}
+
+	if (*content == EXFAT_BAD_CLUSTER) {
+		exfat_fs_error(sb,
+			"invalid access to FAT bad cluster (entry 0x%08x)",
+			loc);
+		return -EIO;
+	}
+
+	if (*content != EXFAT_EOF_CLUSTER && !is_valid_cluster(sbi, *content)) {
+		exfat_fs_error(sb,
+			"invalid access to FAT (entry 0x%08x) bogus content (0x%08x)",
+			loc, *content);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain,
+		unsigned int len)
+{
+	if (!len)
+		return 0;
+
+	while (len > 1) {
+		if (exfat_ent_set(sb, chain, chain + 1))
+			return -EIO;
+		chain++;
+		len--;
+	}
+
+	if (exfat_ent_set(sb, chain, EXFAT_EOF_CLUSTER))
+		return -EIO;
+	return 0;
+}
+
+int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)
+{
+	unsigned int num_clusters = 0;
+	unsigned int clu;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	/* invalid cluster number */
+	if (p_chain->dir == EXFAT_FREE_CLUSTER ||
+	    p_chain->dir == EXFAT_EOF_CLUSTER ||
+	    p_chain->dir < EXFAT_FIRST_CLUSTER)
+		return 0;
+
+	/* no cluster to truncate */
+	if (p_chain->size == 0)
+		return 0;
+
+	/* check cluster validation */
+	if (p_chain->dir < 2 && p_chain->dir >= sbi->num_clusters) {
+		exfat_msg(sb, KERN_ERR, "invalid start cluster (%u)",
+				p_chain->dir);
+		return -EIO;
+	}
+
+	set_bit(EXFAT_SB_DIRTY, &sbi->s_state);
+	clu = p_chain->dir;
+
+	if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
+		do {
+			exfat_clear_bitmap(inode, clu);
+			clu++;
+
+			num_clusters++;
+		} while (num_clusters < p_chain->size);
+	} else {
+		do {
+			exfat_clear_bitmap(inode, clu);
+
+			if (exfat_get_next_cluster(sb, &clu))
+				goto dec_used_clus;
+
+			num_clusters++;
+		} while (clu != EXFAT_EOF_CLUSTER);
+	}
+
+dec_used_clus:
+	sbi->used_clusters -= num_clusters;
+	return 0;
+}
+
+int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,
+		unsigned int *ret_clu)
+{
+	unsigned int clu, next;
+	unsigned int count = 0;
+
+	next = p_chain->dir;
+	if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
+		*ret_clu = next + p_chain->size - 1;
+		return 0;
+	}
+
+	do {
+		count++;
+		clu = next;
+		if (exfat_ent_get(sb, clu, &next))
+			return -EIO;
+	} while (next != EXFAT_EOF_CLUSTER);
+
+	if (p_chain->size != count) {
+		exfat_fs_error(sb,
+			"bogus directory size (clus : ondisk(%d) != counted(%d))",
+			p_chain->size, count);
+		return -EIO;
+	}
+
+	*ret_clu = clu;
+	return 0;
+}
+
+static inline int exfat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
+{
+	int i, err = 0;
+
+	for (i = 0; i < nr_bhs; i++)
+		write_dirty_buffer(bhs[i], 0);
+
+	for (i = 0; i < nr_bhs; i++) {
+		wait_on_buffer(bhs[i]);
+		if (!err && !buffer_uptodate(bhs[i]))
+			err = -EIO;
+	}
+	return err;
+}
+
+int exfat_zeroed_cluster(struct inode *dir, unsigned int clu)
+{
+	struct super_block *sb = dir->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct buffer_head *bhs[MAX_BUF_PER_PAGE];
+	int nr_bhs = MAX_BUF_PER_PAGE;
+	sector_t blknr, last_blknr;
+	int err, i, n;
+
+	blknr = exfat_cluster_to_sector(sbi, clu);
+	last_blknr = blknr + sbi->sect_per_clus;
+
+	if (last_blknr > sbi->num_sectors && sbi->num_sectors > 0) {
+		exfat_fs_error_ratelimit(sb,
+			"%s: out of range(sect:%llu len:%u)",
+			__func__, (unsigned long long)blknr,
+			sbi->sect_per_clus);
+		return -EIO;
+	}
+
+	/* Zeroing the unused blocks on this cluster */
+	n = 0;
+	while (blknr < last_blknr) {
+		bhs[n] = sb_getblk(sb, blknr);
+		if (!bhs[n]) {
+			err = -ENOMEM;
+			goto release_bhs;
+		}
+		memset(bhs[n]->b_data, 0, sb->s_blocksize);
+		exfat_update_bh(sb, bhs[n], 0);
+
+		n++;
+		blknr++;
+
+		if (n == nr_bhs) {
+			if (IS_DIRSYNC(dir)) {
+				err = exfat_sync_bhs(bhs, n);
+				if (err)
+					goto release_bhs;
+			}
+
+			for (i = 0; i < n; i++)
+				brelse(bhs[i]);
+			n = 0;
+		}
+	}
+
+	if (IS_DIRSYNC(dir)) {
+		err = exfat_sync_bhs(bhs, n);
+		if (err)
+			goto release_bhs;
+	}
+
+	for (i = 0; i < n; i++)
+		brelse(bhs[i]);
+
+	return 0;
+
+release_bhs:
+	exfat_msg(sb, KERN_ERR, "failed zeroed sect %llu\n",
+		(unsigned long long)blknr);
+	for (i = 0; i < n; i++)
+		bforget(bhs[i]);
+	return err;
+}
+
+int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
+		struct exfat_chain *p_chain)
+{
+	int ret = -ENOSPC;
+	unsigned int num_clusters = 0, total_cnt;
+	unsigned int hint_clu, new_clu, last_clu = EXFAT_EOF_CLUSTER;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	total_cnt = EXFAT_DATA_CLUSTER_COUNT(sbi);
+
+	if (unlikely(total_cnt < sbi->used_clusters)) {
+		exfat_fs_error_ratelimit(sb,
+			"%s: invalid used clusters(t:%u,u:%u)\n",
+			__func__, total_cnt, sbi->used_clusters);
+		return -EIO;
+	}
+
+	if (num_alloc > total_cnt - sbi->used_clusters)
+		return -ENOSPC;
+
+	hint_clu = p_chain->dir;
+	/* find new cluster */
+	if (hint_clu == EXFAT_EOF_CLUSTER) {
+		if (sbi->clu_srch_ptr < EXFAT_FIRST_CLUSTER) {
+			exfat_msg(sb, KERN_ERR,
+				"sbi->clu_srch_ptr is invalid (%u)\n",
+				sbi->clu_srch_ptr);
+			sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
+		}
+
+		hint_clu = exfat_find_free_bitmap(sb, sbi->clu_srch_ptr);
+		if (hint_clu == EXFAT_EOF_CLUSTER)
+			return -ENOSPC;
+	}
+
+	/* check cluster validation */
+	if (hint_clu < EXFAT_FIRST_CLUSTER && hint_clu >= sbi->num_clusters) {
+		exfat_msg(sb, KERN_ERR, "hint_cluster is invalid (%u)\n",
+			hint_clu);
+		hint_clu = EXFAT_FIRST_CLUSTER;
+		if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
+			if (exfat_chain_cont_cluster(sb, p_chain->dir,
+					num_clusters))
+				return -EIO;
+			p_chain->flags = ALLOC_FAT_CHAIN;
+		}
+	}
+
+	set_bit(EXFAT_SB_DIRTY, &sbi->s_state);
+
+	p_chain->dir = EXFAT_EOF_CLUSTER;
+
+	while ((new_clu = exfat_find_free_bitmap(sb, hint_clu)) !=
+	       EXFAT_EOF_CLUSTER) {
+		if (new_clu != hint_clu &&
+		    p_chain->flags == ALLOC_NO_FAT_CHAIN) {
+			if (exfat_chain_cont_cluster(sb, p_chain->dir,
+					num_clusters)) {
+				ret = -EIO;
+				goto free_cluster;
+			}
+			p_chain->flags = ALLOC_FAT_CHAIN;
+		}
+
+		/* update allocation bitmap */
+		if (exfat_set_bitmap(inode, new_clu)) {
+			ret = -EIO;
+			goto free_cluster;
+		}
+
+		num_clusters++;
+
+		/* update FAT table */
+		if (p_chain->flags == ALLOC_FAT_CHAIN) {
+			if (exfat_ent_set(sb, new_clu, EXFAT_EOF_CLUSTER)) {
+				ret = -EIO;
+				goto free_cluster;
+			}
+		}
+
+		if (p_chain->dir == EXFAT_EOF_CLUSTER) {
+			p_chain->dir = new_clu;
+		} else if (p_chain->flags == ALLOC_FAT_CHAIN) {
+			if (exfat_ent_set(sb, last_clu, new_clu)) {
+				ret = -EIO;
+				goto free_cluster;
+			}
+		}
+		last_clu = new_clu;
+
+		if (--num_alloc == 0) {
+			sbi->clu_srch_ptr = hint_clu;
+			sbi->used_clusters += num_clusters;
+
+			p_chain->size += num_clusters;
+			return 0;
+		}
+
+		hint_clu = new_clu + 1;
+		if (hint_clu >= sbi->num_clusters) {
+			hint_clu = EXFAT_FIRST_CLUSTER;
+
+			if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
+				if (exfat_chain_cont_cluster(sb, p_chain->dir,
+						num_clusters)) {
+					ret = -EIO;
+					goto free_cluster;
+				}
+				p_chain->flags = ALLOC_FAT_CHAIN;
+			}
+		}
+	}
+free_cluster:
+	if (num_clusters)
+		exfat_free_cluster(inode, p_chain);
+	return ret;
+}
+
+int exfat_count_num_clusters(struct super_block *sb,
+		struct exfat_chain *p_chain, unsigned int *ret_count)
+{
+	unsigned int i, count;
+	unsigned int clu;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	if (!p_chain->dir || p_chain->dir == EXFAT_EOF_CLUSTER) {
+		*ret_count = 0;
+		return 0;
+	}
+
+	if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
+		*ret_count = p_chain->size;
+		return 0;
+	}
+
+	clu = p_chain->dir;
+	count = 0;
+	for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters; i++) {
+		count++;
+		if (exfat_ent_get(sb, clu, &clu))
+			return -EIO;
+		if (clu == EXFAT_EOF_CLUSTER)
+			break;
+	}
+
+	*ret_count = count;
+	return 0;
+}

fs/exfat/file.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/slab.h>
+#include <linux/cred.h>
+#include <linux/buffer_head.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+
+static int exfat_cont_expand(struct inode *inode, loff_t size)
+{
+	struct address_space *mapping = inode->i_mapping;
+	loff_t start = i_size_read(inode), count = size - i_size_read(inode);
+	int err, err2;
+
+	err = generic_cont_expand_simple(inode, size);
+	if (err)
+		return err;
+
+	inode->i_ctime = inode->i_mtime = current_time(inode);
+	mark_inode_dirty(inode);
+
+	if (!IS_SYNC(inode))
+		return 0;
+
+	err = filemap_fdatawrite_range(mapping, start, start + count - 1);
+	err2 = sync_mapping_buffers(mapping);
+	if (!err)
+		err = err2;
+	err2 = write_inode_now(inode, 1);
+	if (!err)
+		err = err2;
+	if (err)
+		return err;
+
+	return filemap_fdatawait_range(mapping, start, start + count - 1);
+}
+
+static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode)
+{
+	mode_t allow_utime = sbi->options.allow_utime;
+
+	if (!uid_eq(current_fsuid(), inode->i_uid)) {
+		if (in_group_p(inode->i_gid))
+			allow_utime >>= 3;
+		if (allow_utime & MAY_WRITE)
+			return true;
+	}
+
+	/* use a default check */
+	return false;
+}
+
+static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
+		struct inode *inode, umode_t *mode_ptr)
+{
+	mode_t i_mode, mask, perm;
+
+	i_mode = inode->i_mode;
+
+	mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ?
+		sbi->options.fs_fmask : sbi->options.fs_dmask;
+	perm = *mode_ptr & ~(S_IFMT | mask);
+
+	/* Of the r and x bits, all (subject to umask) must be present.*/
+	if ((perm & 0555) != (i_mode & 0555))
+		return -EPERM;
+
+	if (exfat_mode_can_hold_ro(inode)) {
+		/*
+		 * Of the w bits, either all (subject to umask) or none must
+		 * be present.
+		 */
+		if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
+			return -EPERM;
+	} else {
+		/*
+		 * If exfat_mode_can_hold_ro(inode) is false, can't change
+		 * w bits.
+		 */
+		if ((perm & 0222) != (0222 & ~mask))
+			return -EPERM;
+	}
+
+	*mode_ptr &= S_IFMT | perm;
+
+	return 0;
+}
+
+/* resize the file length */
+int __exfat_truncate(struct inode *inode, loff_t new_size)
+{
+	unsigned int num_clusters_new, num_clusters_phys;
+	unsigned int last_clu = EXFAT_FREE_CLUSTER;
+	struct exfat_chain clu;
+	struct exfat_dentry *ep, *ep2;
+	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_entry_set_cache *es = NULL;
+	int evict = (ei->dir.dir == DIR_DELETED) ? 1 : 0;
+
+	/* check if the given file ID is opened */
+	if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
+		return -EPERM;
+
+	exfat_set_vol_flags(sb, VOL_DIRTY);
+
+	num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
+	num_clusters_phys =
+		EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk, sbi);
+
+	exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
+
+	if (new_size > 0) {
+		/*
+		 * Truncate FAT chain num_clusters after the first cluster
+		 * num_clusters = min(new, phys);
+		 */
+		unsigned int num_clusters =
+			min(num_clusters_new, num_clusters_phys);
+
+		/*
+		 * Follow FAT chain
+		 * (defensive coding - works fine even with corrupted FAT table
+		 */
+		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
+			clu.dir += num_clusters;
+			clu.size -= num_clusters;
+		} else {
+			while (num_clusters > 0) {
+				last_clu = clu.dir;
+				if (exfat_get_next_cluster(sb, &(clu.dir)))
+					return -EIO;
+
+				num_clusters--;
+				clu.size--;
+			}
+		}
+	} else {
+		ei->flags = ALLOC_NO_FAT_CHAIN;
+		ei->start_clu = EXFAT_EOF_CLUSTER;
+	}
+
+	i_size_write(inode, new_size);
+
+	if (ei->type == TYPE_FILE)
+		ei->attr |= ATTR_ARCHIVE;
+
+	/* update the directory entry */
+	if (!evict) {
+		struct timespec64 ts;
+
+		es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
+				ES_ALL_ENTRIES, &ep);
+		if (!es)
+			return -EIO;
+		ep2 = ep + 1;
+
+		ts = current_time(inode);
+		exfat_set_entry_time(sbi, &ts,
+				&ep->dentry.file.modify_tz,
+				&ep->dentry.file.modify_time,
+				&ep->dentry.file.modify_date,
+				&ep->dentry.file.modify_time_ms);
+		ep->dentry.file.attr = cpu_to_le16(ei->attr);
+
+		/* File size should be zero if there is no cluster allocated */
+		if (ei->start_clu == EXFAT_EOF_CLUSTER) {
+			ep->dentry.stream.valid_size = 0;
+			ep->dentry.stream.size = 0;
+		} else {
+			ep->dentry.stream.valid_size = cpu_to_le64(new_size);
+			ep->dentry.stream.size = ep->dentry.stream.valid_size;
+		}
+
+		if (new_size == 0) {
+			/* Any directory can not be truncated to zero */
+			WARN_ON(ei->type != TYPE_FILE);
+
+			ep2->dentry.stream.flags = ALLOC_FAT_CHAIN;
+			ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
+		}
+
+		if (exfat_update_dir_chksum_with_entry_set(sb, es,
+		    inode_needs_sync(inode)))
+			return -EIO;
+		kfree(es);
+	}
+
+	/* cut off from the FAT chain */
+	if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
+			last_clu != EXFAT_EOF_CLUSTER) {
+		if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
+			return -EIO;
+	}
+
+	/* invalidate cache and free the clusters */
+	/* clear exfat cache */
+	exfat_cache_inval_inode(inode);
+
+	/* hint information */
+	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
+	ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
+	if (ei->rwoffset > new_size)
+		ei->rwoffset = new_size;
+
+	/* hint_stat will be used if this is directory. */
+	ei->hint_stat.eidx = 0;
+	ei->hint_stat.clu = ei->start_clu;
+	ei->hint_femp.eidx = EXFAT_HINT_NONE;
+
+	/* free the clusters */
+	if (exfat_free_cluster(inode, &clu))
+		return -EIO;
+
+	exfat_set_vol_flags(sb, VOL_CLEAN);
+
+	return 0;
+}
+
+void exfat_truncate(struct inode *inode, loff_t size)
+{
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	unsigned int blocksize = 1 << inode->i_blkbits;
+	loff_t aligned_size;
+	int err;
+
+	mutex_lock(&sbi->s_lock);
+	if (EXFAT_I(inode)->start_clu == 0) {
+		/*
+		 * Empty start_clu != ~0 (not allocated)
+		 */
+		exfat_fs_error(sb, "tried to truncate zeroed cluster.");
+		goto write_size;
+	}
+
+	err = __exfat_truncate(inode, i_size_read(inode));
+	if (err)
+		goto write_size;
+
+	inode->i_ctime = inode->i_mtime = current_time(inode);
+	if (IS_DIRSYNC(inode))
+		exfat_sync_inode(inode);
+	else
+		mark_inode_dirty(inode);
+
+	inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1)) &
+			~(sbi->cluster_size - 1)) >> inode->i_blkbits;
+write_size:
+	aligned_size = i_size_read(inode);
+	if (aligned_size & (blocksize - 1)) {
+		aligned_size |= (blocksize - 1);
+		aligned_size++;
+	}
+
+	if (EXFAT_I(inode)->i_size_ondisk > i_size_read(inode))
+		EXFAT_I(inode)->i_size_ondisk = aligned_size;
+
+	if (EXFAT_I(inode)->i_size_aligned > i_size_read(inode))
+		EXFAT_I(inode)->i_size_aligned = aligned_size;
+	mutex_unlock(&sbi->s_lock);
+}
+
+int exfat_getattr(const struct path *path, struct kstat *stat,
+		unsigned int request_mask, unsigned int query_flags)
+{
+	struct inode *inode = d_backing_inode(path->dentry);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+
+	generic_fillattr(inode, stat);
+	stat->result_mask |= STATX_BTIME;
+	stat->btime.tv_sec = ei->i_crtime.tv_sec;
+	stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
+	stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
+	return 0;
+}
+
+int exfat_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
+	struct inode *inode = dentry->d_inode;
+	unsigned int ia_valid;
+	int error;
+
+	if ((attr->ia_valid & ATTR_SIZE) &&
+	    attr->ia_size > i_size_read(inode)) {
+		error = exfat_cont_expand(inode, attr->ia_size);
+		if (error || attr->ia_valid == ATTR_SIZE)
+			return error;
+		attr->ia_valid &= ~ATTR_SIZE;
+	}
+
+	/* Check for setting the inode time. */
+	ia_valid = attr->ia_valid;
+	if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
+	    exfat_allow_set_time(sbi, inode)) {
+		attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
+				ATTR_TIMES_SET);
+	}
+
+	error = setattr_prepare(dentry, attr);
+	attr->ia_valid = ia_valid;
+	if (error)
+		goto out;
+
+	if (((attr->ia_valid & ATTR_UID) &&
+	     !uid_eq(attr->ia_uid, sbi->options.fs_uid)) ||
+	    ((attr->ia_valid & ATTR_GID) &&
+	     !gid_eq(attr->ia_gid, sbi->options.fs_gid)) ||
+	    ((attr->ia_valid & ATTR_MODE) &&
+	     (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
+		error = -EPERM;
+		goto out;
+	}
+
+	/*
+	 * We don't return -EPERM here. Yes, strange, but this is too
+	 * old behavior.
+	 */
+	if (attr->ia_valid & ATTR_MODE) {
+		if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
+			attr->ia_valid &= ~ATTR_MODE;
+	}
+
+	if (attr->ia_valid & ATTR_SIZE) {
+		error = exfat_block_truncate_page(inode, attr->ia_size);
+		if (error)
+			goto out;
+
+		down_write(&EXFAT_I(inode)->truncate_lock);
+		truncate_setsize(inode, attr->ia_size);
+		exfat_truncate(inode, attr->ia_size);
+		up_write(&EXFAT_I(inode)->truncate_lock);
+	}
+
+	setattr_copy(inode, attr);
+	mark_inode_dirty(inode);
+
+out:
+	return error;
+}
+
+const struct file_operations exfat_file_operations = {
+	.llseek      = generic_file_llseek,
+	.read_iter   = generic_file_read_iter,
+	.write_iter  = generic_file_write_iter,
+	.mmap        = generic_file_mmap,
+	.fsync       = generic_file_fsync,
+	.splice_read = generic_file_splice_read,
+};
+
+const struct inode_operations exfat_file_inode_operations = {
+	.setattr     = exfat_setattr,
+	.getattr     = exfat_getattr,
+};

fs/exfat/inode.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/init.h>
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/time.h>
+#include <linux/writeback.h>
+#include <linux/uio.h>
+#include <linux/random.h>
+#include <linux/iversion.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+
+static int __exfat_write_inode(struct inode *inode, int sync)
+{
+	int ret = -EIO;
+	unsigned long long on_disk_size;
+	struct exfat_dentry *ep, *ep2;
+	struct exfat_entry_set_cache *es = NULL;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	bool is_dir = (ei->type == TYPE_DIR) ? true : false;
+
+	if (inode->i_ino == EXFAT_ROOT_INO)
+		return 0;
+
+	/*
+	 * If the indode is already unlinked, there is no need for updating it.
+	 */
+	if (ei->dir.dir == DIR_DELETED)
+		return 0;
+
+	if (is_dir && ei->dir.dir == sbi->root_dir && ei->entry == -1)
+		return 0;
+
+	exfat_set_vol_flags(sb, VOL_DIRTY);
+
+	/* get the directory entry of given file or directory */
+	es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES,
+		&ep);
+	if (!es)
+		return -EIO;
+	ep2 = ep + 1;
+
+	ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode));
+
+	/* set FILE_INFO structure using the acquired struct exfat_dentry */
+	exfat_set_entry_time(sbi, &ei->i_crtime,
+			&ep->dentry.file.create_tz,
+			&ep->dentry.file.create_time,
+			&ep->dentry.file.create_date,
+			&ep->dentry.file.create_time_ms);
+	exfat_set_entry_time(sbi, &inode->i_mtime,
+			&ep->dentry.file.modify_tz,
+			&ep->dentry.file.modify_time,
+			&ep->dentry.file.modify_date,
+			&ep->dentry.file.modify_time_ms);
+	exfat_set_entry_time(sbi, &inode->i_atime,
+			&ep->dentry.file.access_tz,
+			&ep->dentry.file.access_time,
+			&ep->dentry.file.access_date,
+			NULL);
+
+	/* File size should be zero if there is no cluster allocated */
+	on_disk_size = i_size_read(inode);
+
+	if (ei->start_clu == EXFAT_EOF_CLUSTER)
+		on_disk_size = 0;
+
+	ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_size);
+	ep2->dentry.stream.size = ep2->dentry.stream.valid_size;
+
+	ret = exfat_update_dir_chksum_with_entry_set(sb, es, sync);
+	kfree(es);
+	return ret;
+}
+
+int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	int ret;
+
+	mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
+	ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
+	mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
+
+	return ret;
+}
+
+void exfat_sync_inode(struct inode *inode)
+{
+	lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock);
+	__exfat_write_inode(inode, 1);
+}
+
+/*
+ * Input: inode, (logical) clu_offset, target allocation area
+ * Output: errcode, cluster number
+ * *clu = (~0), if it's unable to allocate a new cluster
+ */
+static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
+		unsigned int *clu, int create)
+{
+	int ret, modified = false;
+	unsigned int last_clu;
+	struct exfat_chain new_clu;
+	struct exfat_dentry *ep;
+	struct exfat_entry_set_cache *es = NULL;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	unsigned int local_clu_offset = clu_offset;
+	unsigned int num_to_be_allocated = 0, num_clusters = 0;
+
+	ei->rwoffset = EXFAT_CLU_TO_B(clu_offset, sbi);
+
+	if (EXFAT_I(inode)->i_size_ondisk > 0)
+		num_clusters =
+			EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk,
+			sbi);
+
+	if (clu_offset >= num_clusters)
+		num_to_be_allocated = clu_offset - num_clusters + 1;
+
+	if (!create && (num_to_be_allocated > 0)) {
+		*clu = EXFAT_EOF_CLUSTER;
+		return 0;
+	}
+
+	*clu = last_clu = ei->start_clu;
+
+	if (ei->flags == ALLOC_NO_FAT_CHAIN) {
+		if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {
+			last_clu += clu_offset - 1;
+
+			if (clu_offset == num_clusters)
+				*clu = EXFAT_EOF_CLUSTER;
+			else
+				*clu += clu_offset;
+		}
+	} else if (ei->type == TYPE_FILE) {
+		unsigned int fclus = 0;
+		int err = exfat_get_cluster(inode, clu_offset,
+				&fclus, clu, &last_clu, 1);
+		if (err)
+			return -EIO;
+
+		clu_offset -= fclus;
+	} else {
+		/* hint information */
+		if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER &&
+		    ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) {
+			clu_offset -= ei->hint_bmap.off;
+			/* hint_bmap.clu should be valid */
+			WARN_ON(ei->hint_bmap.clu < 2);
+			*clu = ei->hint_bmap.clu;
+		}
+
+		while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {
+			last_clu = *clu;
+			if (exfat_get_next_cluster(sb, clu))
+				return -EIO;
+			clu_offset--;
+		}
+	}
+
+	if (*clu == EXFAT_EOF_CLUSTER) {
+		exfat_set_vol_flags(sb, VOL_DIRTY);
+
+		new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?
+				EXFAT_EOF_CLUSTER : last_clu + 1;
+		new_clu.size = 0;
+		new_clu.flags = ei->flags;
+
+		/* allocate a cluster */
+		if (num_to_be_allocated < 1) {
+			/* Broken FAT (i_sze > allocated FAT) */
+			exfat_fs_error(sb, "broken FAT chain.");
+			return -EIO;
+		}
+
+		ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu);
+		if (ret)
+			return ret;
+
+		if (new_clu.dir == EXFAT_EOF_CLUSTER ||
+		    new_clu.dir == EXFAT_FREE_CLUSTER) {
+			exfat_fs_error(sb,
+				"bogus cluster new allocated (last_clu : %u, new_clu : %u)",
+				last_clu, new_clu.dir);
+			return -EIO;
+		}
+
+		/* append to the FAT chain */
+		if (last_clu == EXFAT_EOF_CLUSTER) {
+			if (new_clu.flags == ALLOC_FAT_CHAIN)
+				ei->flags = ALLOC_FAT_CHAIN;
+			ei->start_clu = new_clu.dir;
+			modified = true;
+		} else {
+			if (new_clu.flags != ei->flags) {
+				/* no-fat-chain bit is disabled,
+				 * so fat-chain should be synced with
+				 * alloc-bitmap
+				 */
+				exfat_chain_cont_cluster(sb, ei->start_clu,
+					num_clusters);
+				ei->flags = ALLOC_FAT_CHAIN;
+				modified = true;
+			}
+			if (new_clu.flags == ALLOC_FAT_CHAIN)
+				if (exfat_ent_set(sb, last_clu, new_clu.dir))
+					return -EIO;
+		}
+
+		num_clusters += num_to_be_allocated;
+		*clu = new_clu.dir;
+
+		if (ei->dir.dir != DIR_DELETED) {
+			es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
+				ES_ALL_ENTRIES, &ep);
+			if (!es)
+				return -EIO;
+			/* get stream entry */
+			ep++;
+
+			/* update directory entry */
+			if (modified) {
+				if (ep->dentry.stream.flags != ei->flags)
+					ep->dentry.stream.flags = ei->flags;
+
+				if (le32_to_cpu(ep->dentry.stream.start_clu) !=
+						ei->start_clu)
+					ep->dentry.stream.start_clu =
+						cpu_to_le32(ei->start_clu);
+
+				ep->dentry.stream.valid_size =
+					cpu_to_le64(i_size_read(inode));
+				ep->dentry.stream.size =
+					ep->dentry.stream.valid_size;
+			}
+
+			if (exfat_update_dir_chksum_with_entry_set(sb, es,
+			    inode_needs_sync(inode)))
+				return -EIO;
+			kfree(es);
+
+		} /* end of if != DIR_DELETED */
+
+		inode->i_blocks +=
+			num_to_be_allocated << sbi->sect_per_clus_bits;
+
+		/*
+		 * Move *clu pointer along FAT chains (hole care) because the
+		 * caller of this function expect *clu to be the last cluster.
+		 * This only works when num_to_be_allocated >= 2,
+		 * *clu = (the first cluster of the allocated chain) =>
+		 * (the last cluster of ...)
+		 */
+		if (ei->flags == ALLOC_NO_FAT_CHAIN) {
+			*clu += num_to_be_allocated - 1;
+		} else {
+			while (num_to_be_allocated > 1) {
+				if (exfat_get_next_cluster(sb, clu))
+					return -EIO;
+				num_to_be_allocated--;
+			}
+		}
+
+	}
+
+	/* hint information */
+	ei->hint_bmap.off = local_clu_offset;
+	ei->hint_bmap.clu = *clu;
+
+	return 0;
+}
+
+static int exfat_map_new_buffer(struct exfat_inode_info *ei,
+		struct buffer_head *bh, loff_t pos)
+{
+	if (buffer_delay(bh) && pos > ei->i_size_aligned)
+		return -EIO;
+	set_buffer_new(bh);
+
+	/*
+	 * Adjust i_size_aligned if i_size_ondisk is bigger than it.
+	 */
+	if (ei->i_size_ondisk > ei->i_size_aligned)
+		ei->i_size_aligned = ei->i_size_ondisk;
+	return 0;
+}
+
+static int exfat_get_block(struct inode *inode, sector_t iblock,
+		struct buffer_head *bh_result, int create)
+{
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
+	int err = 0;
+	unsigned long mapped_blocks = 0;
+	unsigned int cluster, sec_offset;
+	sector_t last_block;
+	sector_t phys = 0;
+	loff_t pos;
+
+	mutex_lock(&sbi->s_lock);
+	last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb);
+	if (iblock >= last_block && !create)
+		goto done;
+
+	/* Is this block already allocated? */
+	err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits,
+			&cluster, create);
+	if (err) {
+		if (err != -ENOSPC)
+			exfat_fs_error_ratelimit(sb,
+				"failed to bmap (inode : %p iblock : %llu, err : %d)",
+				inode, (unsigned long long)iblock, err);
+		goto unlock_ret;
+	}
+
+	if (cluster == EXFAT_EOF_CLUSTER)
+		goto done;
+
+	/* sector offset in cluster */
+	sec_offset = iblock & (sbi->sect_per_clus - 1);
+
+	phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset;
+	mapped_blocks = sbi->sect_per_clus - sec_offset;
+	max_blocks = min(mapped_blocks, max_blocks);
+
+	/* Treat newly added block / cluster */
+	if (iblock < last_block)
+		create = 0;
+
+	if (create || buffer_delay(bh_result)) {
+		pos = EXFAT_BLK_TO_B((iblock + 1), sb);
+		if (ei->i_size_ondisk < pos)
+			ei->i_size_ondisk = pos;
+	}
+
+	if (create) {
+		err = exfat_map_new_buffer(ei, bh_result, pos);
+		if (err) {
+			exfat_fs_error(sb,
+					"requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n",
+					pos, ei->i_size_aligned);
+			goto unlock_ret;
+		}
+	}
+
+	if (buffer_delay(bh_result))
+		clear_buffer_delay(bh_result);
+	map_bh(bh_result, sb, phys);
+done:
+	bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);
+unlock_ret:
+	mutex_unlock(&sbi->s_lock);
+	return err;
+}
+
+static int exfat_readpage(struct file *file, struct page *page)
+{
+	return mpage_readpage(page, exfat_get_block);
+}
+
+static int exfat_readpages(struct file *file, struct address_space *mapping,
+		struct list_head *pages, unsigned int nr_pages)
+{
+	return mpage_readpages(mapping, pages, nr_pages, exfat_get_block);
+}
+
+static int exfat_writepage(struct page *page, struct writeback_control *wbc)
+{
+	return block_write_full_page(page, exfat_get_block, wbc);
+}
+
+static int exfat_writepages(struct address_space *mapping,
+		struct writeback_control *wbc)
+{
+	return mpage_writepages(mapping, wbc, exfat_get_block);
+}
+
+static void exfat_write_failed(struct address_space *mapping, loff_t to)
+{
+	struct inode *inode = mapping->host;
+
+	if (to > i_size_read(inode)) {
+		truncate_pagecache(inode, i_size_read(inode));
+		exfat_truncate(inode, EXFAT_I(inode)->i_size_aligned);
+	}
+}
+
+static int exfat_write_begin(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned int len, unsigned int flags,
+		struct page **pagep, void **fsdata)
+{
+	int ret;
+
+	*pagep = NULL;
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+			       exfat_get_block,
+			       &EXFAT_I(mapping->host)->i_size_ondisk);
+
+	if (ret < 0)
+		exfat_write_failed(mapping, pos+len);
+
+	return ret;
+}
+
+static int exfat_write_end(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned int len, unsigned int copied,
+		struct page *pagep, void *fsdata)
+{
+	struct inode *inode = mapping->host;
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	int err;
+
+	err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
+
+	if (EXFAT_I(inode)->i_size_aligned < i_size_read(inode)) {
+		exfat_fs_error(inode->i_sb,
+			"invalid size(size(%llu) > aligned(%llu)\n",
+			i_size_read(inode), EXFAT_I(inode)->i_size_aligned);
+		return -EIO;
+	}
+
+	if (err < len)
+		exfat_write_failed(mapping, pos+len);
+
+	if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) {
+		inode->i_mtime = inode->i_ctime = current_time(inode);
+		ei->attr |= ATTR_ARCHIVE;
+		mark_inode_dirty(inode);
+	}
+
+	return err;
+}
+
+static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct address_space *mapping = iocb->ki_filp->f_mapping;
+	struct inode *inode = mapping->host;
+	loff_t size = iocb->ki_pos + iov_iter_count(iter);
+	int rw = iov_iter_rw(iter);
+	ssize_t ret;
+
+	if (rw == WRITE) {
+		/*
+		 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
+		 * so we need to update the ->i_size_aligned to block boundary.
+		 *
+		 * But we must fill the remaining area or hole by nul for
+		 * updating ->i_size_aligned
+		 *
+		 * Return 0, and fallback to normal buffered write.
+		 */
+		if (EXFAT_I(inode)->i_size_aligned < size)
+			return 0;
+	}
+
+	/*
+	 * Need to use the DIO_LOCKING for avoiding the race
+	 * condition of exfat_get_block() and ->truncate().
+	 */
+	ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block);
+	if (ret < 0 && (rw & WRITE))
+		exfat_write_failed(mapping, size);
+	return ret;
+}
+
+static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block)
+{
+	sector_t blocknr;
+
+	/* exfat_get_cluster() assumes the requested blocknr isn't truncated. */
+	down_read(&EXFAT_I(mapping->host)->truncate_lock);
+	blocknr = generic_block_bmap(mapping, block, exfat_get_block);
+	up_read(&EXFAT_I(mapping->host)->truncate_lock);
+	return blocknr;
+}
+
+/*
+ * exfat_block_truncate_page() zeroes out a mapping from file offset `from'
+ * up to the end of the block which corresponds to `from'.
+ * This is required during truncate to physically zeroout the tail end
+ * of that block so it doesn't yield old data if the file is later grown.
+ * Also, avoid causing failure from fsx for cases of "data past EOF"
+ */
+int exfat_block_truncate_page(struct inode *inode, loff_t from)
+{
+	return block_truncate_page(inode->i_mapping, from, exfat_get_block);
+}
+
+static const struct address_space_operations exfat_aops = {
+	.readpage	= exfat_readpage,
+	.readpages	= exfat_readpages,
+	.writepage	= exfat_writepage,
+	.writepages	= exfat_writepages,
+	.write_begin	= exfat_write_begin,
+	.write_end	= exfat_write_end,
+	.direct_IO	= exfat_direct_IO,
+	.bmap		= exfat_aop_bmap
+};
+
+static inline unsigned long exfat_hash(loff_t i_pos)
+{
+	return hash_32(i_pos, EXFAT_HASH_BITS);
+}
+
+void exfat_hash_inode(struct inode *inode, loff_t i_pos)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
+	struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);
+
+	spin_lock(&sbi->inode_hash_lock);
+	EXFAT_I(inode)->i_pos = i_pos;
+	hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head);
+	spin_unlock(&sbi->inode_hash_lock);
+}
+
+void exfat_unhash_inode(struct inode *inode)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
+
+	spin_lock(&sbi->inode_hash_lock);
+	hlist_del_init(&EXFAT_I(inode)->i_hash_fat);
+	EXFAT_I(inode)->i_pos = 0;
+	spin_unlock(&sbi->inode_hash_lock);
+}
+
+struct inode *exfat_iget(struct super_block *sb, loff_t i_pos)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_inode_info *info;
+	struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos);
+	struct inode *inode = NULL;
+
+	spin_lock(&sbi->inode_hash_lock);
+	hlist_for_each_entry(info, head, i_hash_fat) {
+		WARN_ON(info->vfs_inode.i_sb != sb);
+
+		if (i_pos != info->i_pos)
+			continue;
+		inode = igrab(&info->vfs_inode);
+		if (inode)
+			break;
+	}
+	spin_unlock(&sbi->inode_hash_lock);
+	return inode;
+}
+
+/* doesn't deal with root inode */
+static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	loff_t size = info->size;
+
+	memcpy(&ei->dir, &info->dir, sizeof(struct exfat_chain));
+	ei->entry = info->entry;
+	ei->attr = info->attr;
+	ei->start_clu = info->start_clu;
+	ei->flags = info->flags;
+	ei->type = info->type;
+
+	ei->version = 0;
+	ei->hint_stat.eidx = 0;
+	ei->hint_stat.clu = info->start_clu;
+	ei->hint_femp.eidx = EXFAT_HINT_NONE;
+	ei->rwoffset = 0;
+	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
+	ei->i_pos = 0;
+
+	inode->i_uid = sbi->options.fs_uid;
+	inode->i_gid = sbi->options.fs_gid;
+	inode_inc_iversion(inode);
+	inode->i_generation = prandom_u32();
+
+	if (info->attr & ATTR_SUBDIR) { /* directory */
+		inode->i_generation &= ~1;
+		inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);
+		inode->i_op = &exfat_dir_inode_operations;
+		inode->i_fop = &exfat_dir_operations;
+		set_nlink(inode, info->num_subdirs);
+	} else { /* regular file */
+		inode->i_generation |= 1;
+		inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);
+		inode->i_op = &exfat_file_inode_operations;
+		inode->i_fop = &exfat_file_operations;
+		inode->i_mapping->a_ops = &exfat_aops;
+		inode->i_mapping->nrpages = 0;
+	}
+
+	i_size_write(inode, size);
+
+	/* ondisk and aligned size should be aligned with block size */
+	if (size & (inode->i_sb->s_blocksize - 1)) {
+		size |= (inode->i_sb->s_blocksize - 1);
+		size++;
+	}
+
+	ei->i_size_aligned = size;
+	ei->i_size_ondisk = size;
+
+	exfat_save_attr(inode, info->attr);
+
+	inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1)) &
+		~(sbi->cluster_size - 1)) >> inode->i_blkbits;
+	inode->i_mtime = info->mtime;
+	inode->i_ctime = info->mtime;
+	ei->i_crtime = info->crtime;
+	inode->i_atime = info->atime;
+
+	exfat_cache_init_inode(inode);
+
+	return 0;
+}
+
+struct inode *exfat_build_inode(struct super_block *sb,
+		struct exfat_dir_entry *info, loff_t i_pos)
+{
+	struct inode *inode;
+	int err;
+
+	inode = exfat_iget(sb, i_pos);
+	if (inode)
+		goto out;
+	inode = new_inode(sb);
+	if (!inode) {
+		inode = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+	inode->i_ino = iunique(sb, EXFAT_ROOT_INO);
+	inode_set_iversion(inode, 1);
+	err = exfat_fill_inode(inode, info);
+	if (err) {
+		iput(inode);
+		inode = ERR_PTR(err);
+		goto out;
+	}
+	exfat_hash_inode(inode, i_pos);
+	insert_inode_hash(inode);
+out:
+	return inode;
+}
+
+void exfat_evict_inode(struct inode *inode)
+{
+	truncate_inode_pages(&inode->i_data, 0);
+
+	if (!inode->i_nlink) {
+		i_size_write(inode, 0);
+		mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
+		__exfat_truncate(inode, 0);
+		mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
+	}
+
+	invalidate_inode_buffers(inode);
+	clear_inode(inode);
+	exfat_cache_inval_inode(inode);
+	exfat_unhash_inode(inode);
+}

fs/exfat/misc.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Written 1992,1993 by Werner Almesberger
+ *  22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
+ *		 and date_dos2unix for date==0 by Igor Zhbanov([e-mail])
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+
+/*
+ * exfat_fs_error reports a file system problem that might indicate fa data
+ * corruption/inconsistency. Depending on 'errors' mount option the
+ * panic() is called, or error message is printed FAT and nothing is done,
+ * or filesystem is remounted read-only (default behavior).
+ * In case the file system is remounted read-only, it can be made writable
+ * again by remounting it.
+ */
+void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
+{
+	struct exfat_mount_options *opts = &EXFAT_SB(sb)->options;
+	va_list args;
+	struct va_format vaf;
+
+	if (report) {
+		va_start(args, fmt);
+		vaf.fmt = fmt;
+		vaf.va = &args;
+		exfat_msg(sb, KERN_ERR, "error, %pV\n", &vaf);
+		va_end(args);
+	}
+
+	if (opts->errors == EXFAT_ERRORS_PANIC) {
+		panic("exFAT-fs (%s): fs panic from previous error\n",
+			sb->s_id);
+	} else if (opts->errors == EXFAT_ERRORS_RO && !sb_rdonly(sb)) {
+		sb->s_flags |= SB_RDONLY;
+		exfat_msg(sb, KERN_ERR, "Filesystem has been set read-only");
+	}
+}
+
+/*
+ * exfat_msg() - print preformated EXFAT specific messages.
+ * All logs except what uses exfat_fs_error() should be written by exfat_msg()
+ */
+void exfat_msg(struct super_block *sb, const char *level, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	/* level means KERN_ pacility level */
+	printk("%sexFAT-fs (%s): %pV\n", level, sb->s_id, &vaf);
+	va_end(args);
+}
+
+#define SECS_PER_MIN    (60)
+#define TIMEZONE_SEC(x)	((x) * 15 * SECS_PER_MIN)
+
+static void exfat_adjust_tz(struct timespec64 *ts, u8 tz_off)
+{
+	if (tz_off <= 0x3F)
+		ts->tv_sec -= TIMEZONE_SEC(tz_off);
+	else /* 0x40 <= (tz_off & 0x7F) <=0x7F */
+		ts->tv_sec += TIMEZONE_SEC(0x80 - tz_off);
+}
+
+/* Convert a EXFAT time/date pair to a UNIX date (seconds since 1 1 70). */
+void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
+		u8 tz, __le16 time, __le16 date, u8 time_ms)
+{
+	u16 t = le16_to_cpu(time);
+	u16 d = le16_to_cpu(date);
+
+	ts->tv_sec = mktime64(1980 + (d >> 9), d >> 5 & 0x000F, d & 0x001F,
+			      t >> 11, (t >> 5) & 0x003F, (t & 0x001F) << 1);
+
+
+	/* time_ms field represent 0 ~ 199(1990 ms) */
+	if (time_ms) {
+		ts->tv_sec += time_ms / 100;
+		ts->tv_nsec = (time_ms % 100) * 10 * NSEC_PER_MSEC;
+	}
+
+	if (tz & EXFAT_TZ_VALID)
+		/* Adjust timezone to UTC0. */
+		exfat_adjust_tz(ts, tz & ~EXFAT_TZ_VALID);
+	else
+		/* Convert from local time to UTC using time_offset. */
+		ts->tv_sec -= sbi->options.time_offset * SECS_PER_MIN;
+}
+
+/* Convert linear UNIX date to a EXFAT time/date pair. */
+void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
+		u8 *tz, __le16 *time, __le16 *date, u8 *time_ms)
+{
+	struct tm tm;
+	u16 t, d;
+
+	time64_to_tm(ts->tv_sec, 0, &tm);
+	t = (tm.tm_hour << 11) | (tm.tm_min << 5) | (tm.tm_sec >> 1);
+	d = ((tm.tm_year - 80) <<  9) | ((tm.tm_mon + 1) << 5) | tm.tm_mday;
+
+	*time = cpu_to_le16(t);
+	*date = cpu_to_le16(d);
+
+	/* time_ms field represent 0 ~ 199(1990 ms) */
+	if (time_ms)
+		*time_ms = (tm.tm_sec & 1) * 100 +
+			ts->tv_nsec / (10 * NSEC_PER_MSEC);
+
+	/*
+	 * Record 00h value for OffsetFromUtc field and 1 value for OffsetValid
+	 * to indicate that local time and UTC are the same.
+	 */
+	*tz = EXFAT_TZ_VALID;
+}
+
+unsigned short exfat_calc_chksum_2byte(void *data, int len,
+		unsigned short chksum, int type)
+{
+	int i;
+	unsigned char *c = (unsigned char *)data;
+
+	for (i = 0; i < len; i++, c++) {
+		if (((i == 2) || (i == 3)) && (type == CS_DIR_ENTRY))
+			continue;
+		chksum = (((chksum & 1) << 15) | ((chksum & 0xFFFE) >> 1)) +
+			(unsigned short)*c;
+	}
+	return chksum;
+}
+
+void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync)
+{
+	set_bit(EXFAT_SB_DIRTY, &EXFAT_SB(sb)->s_state);
+	set_buffer_uptodate(bh);
+	mark_buffer_dirty(bh);
+
+	if (sync)
+		sync_dirty_buffer(bh);
+}
+
+void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
+		unsigned int size, unsigned char flags)
+{
+	ec->dir = dir;
+	ec->size = size;
+	ec->flags = flags;
+}
+
+void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec)
+{
+	return exfat_chain_set(dup, ec->dir, ec->size, ec->flags);
+}

fs/exfat/namei.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/iversion.h>
+#include <linux/namei.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+#include <linux/nls.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+
+static inline unsigned long exfat_d_version(struct dentry *dentry)
+{
+	return (unsigned long) dentry->d_fsdata;
+}
+
+static inline void exfat_d_version_set(struct dentry *dentry,
+		unsigned long version)
+{
+	dentry->d_fsdata = (void *) version;
+}
+
+/*
+ * If new entry was created in the parent, it could create the 8.3 alias (the
+ * shortname of logname).  So, the parent may have the negative-dentry which
+ * matches the created 8.3 alias.
+ *
+ * If it happened, the negative dentry isn't actually negative anymore.  So,
+ * drop it.
+ */
+static int exfat_d_revalidate(struct dentry *dentry, unsigned int flags)
+{
+	int ret;
+
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	/*
+	 * This is not negative dentry. Always valid.
+	 *
+	 * Note, rename() to existing directory entry will have ->d_inode, and
+	 * will use existing name which isn't specified name by user.
+	 *
+	 * We may be able to drop this positive dentry here. But dropping
+	 * positive dentry isn't good idea. So it's unsupported like
+	 * rename("filename", "FILENAME") for now.
+	 */
+	if (d_really_is_positive(dentry))
+		return 1;
+
+	/*
+	 * Drop the negative dentry, in order to make sure to use the case
+	 * sensitive name which is specified by user if this is for creation.
+	 */
+	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
+		return 0;
+
+	spin_lock(&dentry->d_lock);
+	ret = inode_eq_iversion(d_inode(dentry->d_parent),
+			exfat_d_version(dentry));
+	spin_unlock(&dentry->d_lock);
+	return ret;
+}
+
+/* returns the length of a struct qstr, ignoring trailing dots */
+static unsigned int exfat_striptail_len(unsigned int len, const char *name)
+{
+	while (len && name[len - 1] == '.')
+		len--;
+	return len;
+}
+
+/*
+ * Compute the hash for the exfat name corresponding to the dentry.  If the name
+ * is invalid, we leave the hash code unchanged so that the existing dentry can
+ * be used. The exfat fs routines will return ENOENT or EINVAL as appropriate.
+ */
+static int exfat_d_hash(const struct dentry *dentry, struct qstr *qstr)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct nls_table *t = EXFAT_SB(sb)->nls_io;
+	const unsigned char *name = qstr->name;
+	unsigned int len = exfat_striptail_len(qstr->len, qstr->name);
+	unsigned long hash = init_name_hash(dentry);
+	int i, charlen;
+	wchar_t c;
+
+	for (i = 0; i < len; i += charlen) {
+		charlen = t->char2uni(&name[i], len - i, &c);
+		if (charlen < 0)
+			return charlen;
+		hash = partial_name_hash(exfat_toupper(sb, c), hash);
+	}
+
+	qstr->hash = end_name_hash(hash);
+	return 0;
+}
+
+static int exfat_d_cmp(const struct dentry *dentry, unsigned int len,
+		const char *str, const struct qstr *name)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct nls_table *t = EXFAT_SB(sb)->nls_io;
+	unsigned int alen = exfat_striptail_len(name->len, name->name);
+	unsigned int blen = exfat_striptail_len(len, str);
+	wchar_t c1, c2;
+	int charlen, i;
+
+	if (alen != blen)
+		return 1;
+
+	for (i = 0; i < len; i += charlen) {
+		charlen = t->char2uni(&name->name[i], alen - i, &c1);
+		if (charlen < 0)
+			return 1;
+		if (charlen != t->char2uni(&str[i], blen - i, &c2))
+			return 1;
+
+		if (exfat_toupper(sb, c1) != exfat_toupper(sb, c2))
+			return 1;
+	}
+
+	return 0;
+}
+
+const struct dentry_operations exfat_dentry_ops = {
+	.d_revalidate	= exfat_d_revalidate,
+	.d_hash		= exfat_d_hash,
+	.d_compare	= exfat_d_cmp,
+};
+
+static int exfat_utf8_d_hash(const struct dentry *dentry, struct qstr *qstr)
+{
+	struct super_block *sb = dentry->d_sb;
+	const unsigned char *name = qstr->name;
+	unsigned int len = exfat_striptail_len(qstr->len, qstr->name);
+	unsigned long hash = init_name_hash(dentry);
+	int i, charlen;
+	unicode_t u;
+
+	for (i = 0; i < len; i += charlen) {
+		charlen = utf8_to_utf32(&name[i], len - i, &u);
+		if (charlen < 0)
+			return charlen;
+
+		/*
+		 * Convert to UTF-16: code points above U+FFFF are encoded as
+		 * surrogate pairs.
+		 * exfat_toupper() works only for code points up to the U+FFFF.
+		 */
+		if (u > 0xFFFF) {
+			hash = partial_name_hash(exfat_high_surrogate(u), hash);
+			hash = partial_name_hash(exfat_low_surrogate(u), hash);
+		} else {
+			hash = partial_name_hash(exfat_toupper(sb, u), hash);
+		}
+	}
+
+	qstr->hash = end_name_hash(hash);
+	return 0;
+}
+
+static int exfat_utf8_d_cmp(const struct dentry *dentry, unsigned int len,
+		const char *str, const struct qstr *name)
+{
+	struct super_block *sb = dentry->d_sb;
+	unsigned int alen = exfat_striptail_len(name->len, name->name);
+	unsigned int blen = exfat_striptail_len(len, str);
+	unicode_t u_a, u_b;
+	int charlen, i;
+
+	if (alen != blen)
+		return 1;
+
+	for (i = 0; i < alen; i += charlen) {
+		charlen = utf8_to_utf32(&name->name[i], alen - i, &u_a);
+		if (charlen < 0)
+			return 1;
+		if (charlen != utf8_to_utf32(&str[i], blen - i, &u_b))
+			return 1;
+
+		if (u_a <= 0xFFFF && u_b <= 0xFFFF) {
+			if (exfat_toupper(sb, u_a) != exfat_toupper(sb, u_b))
+				return 1;
+		} else if (u_a > 0xFFFF && u_b > 0xFFFF) {
+			if (exfat_low_surrogate(u_a) !=
+					exfat_low_surrogate(u_b) ||
+			    exfat_high_surrogate(u_a) !=
+					exfat_high_surrogate(u_b))
+				return 1;
+		} else {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+const struct dentry_operations exfat_utf8_dentry_ops = {
+	.d_revalidate	= exfat_d_revalidate,
+	.d_hash		= exfat_utf8_d_hash,
+	.d_compare	= exfat_utf8_d_cmp,
+};
+
+/* used only in search empty_slot() */
+#define CNT_UNUSED_NOHIT        (-1)
+#define CNT_UNUSED_HIT          (-2)
+/* search EMPTY CONTINUOUS "num_entries" entries */
+static int exfat_search_empty_slot(struct super_block *sb,
+		struct exfat_hint_femp *hint_femp, struct exfat_chain *p_dir,
+		int num_entries)
+{
+	int i, dentry, num_empty = 0;
+	int dentries_per_clu;
+	unsigned int type;
+	struct exfat_chain clu;
+	struct exfat_dentry *ep;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct buffer_head *bh;
+
+	dentries_per_clu = sbi->dentries_per_clu;
+
+	if (hint_femp->eidx != EXFAT_HINT_NONE) {
+		dentry = hint_femp->eidx;
+		if (num_entries <= hint_femp->count) {
+			hint_femp->eidx = EXFAT_HINT_NONE;
+			return dentry;
+		}
+
+		exfat_chain_dup(&clu, &hint_femp->cur);
+	} else {
+		exfat_chain_dup(&clu, p_dir);
+		dentry = 0;
+	}
+
+	while (clu.dir != EXFAT_EOF_CLUSTER) {
+		i = dentry & (dentries_per_clu - 1);
+
+		for (; i < dentries_per_clu; i++, dentry++) {
+			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
+			if (!ep)
+				return -EIO;
+			type = exfat_get_entry_type(ep);
+			brelse(bh);
+
+			if (type == TYPE_UNUSED || type == TYPE_DELETED) {
+				num_empty++;
+				if (hint_femp->eidx == EXFAT_HINT_NONE) {
+					hint_femp->eidx = dentry;
+					hint_femp->count = CNT_UNUSED_NOHIT;
+					exfat_chain_set(&hint_femp->cur,
+						clu.dir, clu.size, clu.flags);
+				}
+
+				if (type == TYPE_UNUSED &&
+				    hint_femp->count != CNT_UNUSED_HIT)
+					hint_femp->count = CNT_UNUSED_HIT;
+			} else {
+				if (hint_femp->eidx != EXFAT_HINT_NONE &&
+				    hint_femp->count == CNT_UNUSED_HIT) {
+					/* unused empty group means
+					 * an empty group which includes
+					 * unused dentry
+					 */
+					exfat_fs_error(sb,
+						"found bogus dentry(%d) beyond unused empty group(%d) (start_clu : %u, cur_clu : %u)",
+						dentry, hint_femp->eidx,
+						p_dir->dir, clu.dir);
+					return -EIO;
+				}
+
+				num_empty = 0;
+				hint_femp->eidx = EXFAT_HINT_NONE;
+			}
+
+			if (num_empty >= num_entries) {
+				/* found and invalidate hint_femp */
+				hint_femp->eidx = EXFAT_HINT_NONE;
+				return (dentry - (num_entries - 1));
+			}
+		}
+
+		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
+			if (--clu.size > 0)
+				clu.dir++;
+			else
+				clu.dir = EXFAT_EOF_CLUSTER;
+		} else {
+			if (exfat_get_next_cluster(sb, &clu.dir))
+				return -EIO;
+		}
+	}
+
+	return -ENOSPC;
+}
+
+static int exfat_check_max_dentries(struct inode *inode)
+{
+	if (EXFAT_B_TO_DEN(i_size_read(inode)) >= MAX_EXFAT_DENTRIES) {
+		/*
+		 * exFAT spec allows a dir to grow upto 8388608(256MB)
+		 * dentries
+		 */
+		return -ENOSPC;
+	}
+	return 0;
+}
+
+/* find empty directory entry.
+ * if there isn't any empty slot, expand cluster chain.
+ */
+static int exfat_find_empty_entry(struct inode *inode,
+		struct exfat_chain *p_dir, int num_entries)
+{
+	int dentry;
+	unsigned int ret, last_clu;
+	sector_t sector;
+	loff_t size = 0;
+	struct exfat_chain clu;
+	struct exfat_dentry *ep = NULL;
+	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_hint_femp hint_femp;
+
+	hint_femp.eidx = EXFAT_HINT_NONE;
+
+	if (ei->hint_femp.eidx != EXFAT_HINT_NONE) {
+		memcpy(&hint_femp, &ei->hint_femp,
+				sizeof(struct exfat_hint_femp));
+		ei->hint_femp.eidx = EXFAT_HINT_NONE;
+	}
+
+	while ((dentry = exfat_search_empty_slot(sb, &hint_femp, p_dir,
+					num_entries)) < 0) {
+		if (dentry == -EIO)
+			break;
+
+		if (exfat_check_max_dentries(inode))
+			return -ENOSPC;
+
+		/* we trust p_dir->size regardless of FAT type */
+		if (exfat_find_last_cluster(sb, p_dir, &last_clu))
+			return -EIO;
+
+		/*
+		 * Allocate new cluster to this directory
+		 */
+		exfat_chain_set(&clu, last_clu + 1, 0, p_dir->flags);
+
+		/* allocate a cluster */
+		ret = exfat_alloc_cluster(inode, 1, &clu);
+		if (ret)
+			return ret;
+
+		if (exfat_zeroed_cluster(inode, clu.dir))
+			return -EIO;
+
+		/* append to the FAT chain */
+		if (clu.flags != p_dir->flags) {
+			/* no-fat-chain bit is disabled,
+			 * so fat-chain should be synced with alloc-bitmap
+			 */
+			exfat_chain_cont_cluster(sb, p_dir->dir, p_dir->size);
+			p_dir->flags = ALLOC_FAT_CHAIN;
+			hint_femp.cur.flags = ALLOC_FAT_CHAIN;
+		}
+
+		if (clu.flags == ALLOC_FAT_CHAIN)
+			if (exfat_ent_set(sb, last_clu, clu.dir))
+				return -EIO;
+
+		if (hint_femp.eidx == EXFAT_HINT_NONE) {
+			/* the special case that new dentry
+			 * should be allocated from the start of new cluster
+			 */
+			hint_femp.eidx = EXFAT_B_TO_DEN_IDX(p_dir->size, sbi);
+			hint_femp.count = sbi->dentries_per_clu;
+
+			exfat_chain_set(&hint_femp.cur, clu.dir, 0, clu.flags);
+		}
+		hint_femp.cur.size++;
+		p_dir->size++;
+		size = EXFAT_CLU_TO_B(p_dir->size, sbi);
+
+		/* update the directory entry */
+		if (p_dir->dir != sbi->root_dir) {
+			struct buffer_head *bh;
+
+			ep = exfat_get_dentry(sb,
+				&(ei->dir), ei->entry + 1, &bh, &sector);
+			if (!ep)
+				return -EIO;
+
+			ep->dentry.stream.valid_size = cpu_to_le64(size);
+			ep->dentry.stream.size = ep->dentry.stream.valid_size;
+			ep->dentry.stream.flags = p_dir->flags;
+			exfat_update_bh(sb, bh, IS_DIRSYNC(inode));
+			brelse(bh);
+			if (exfat_update_dir_chksum(inode, &(ei->dir),
+			    ei->entry))
+				return -EIO;
+		}
+
+		/* directory inode should be updated in here */
+		i_size_write(inode, size);
+		EXFAT_I(inode)->i_size_ondisk += sbi->cluster_size;
+		EXFAT_I(inode)->i_size_aligned += sbi->cluster_size;
+		EXFAT_I(inode)->flags = p_dir->flags;
+		inode->i_blocks += 1 << sbi->sect_per_clus_bits;
+	}
+
+	return dentry;
+}
+
+/*
+ * Name Resolution Functions :
+ * Zero if it was successful; otherwise nonzero.
+ */
+static int __exfat_resolve_path(struct inode *inode, const unsigned char *path,
+		struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
+		int lookup)
+{
+	int namelen;
+	int lossy = NLS_NAME_NO_LOSSY;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+
+	/* strip all trailing periods */
+	namelen = exfat_striptail_len(strlen(path), path);
+	if (!namelen)
+		return -ENOENT;
+
+	if (strlen(path) > (MAX_NAME_LENGTH * MAX_CHARSET_SIZE))
+		return -ENAMETOOLONG;
+
+	/*
+	 * strip all leading spaces :
+	 * "MS windows 7" supports leading spaces.
+	 * So we should skip this preprocessing for compatibility.
+	 */
+
+	/* file name conversion :
+	 * If lookup case, we allow bad-name for compatibility.
+	 */
+	namelen = exfat_nls_to_utf16(sb, path, namelen, p_uniname,
+			&lossy);
+	if (namelen < 0)
+		return namelen; /* return error value */
+
+	if ((lossy && !lookup) || !namelen)
+		return -EINVAL;
+
+	exfat_chain_set(p_dir, ei->start_clu,
+		EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
+
+	return 0;
+}
+
+static inline int exfat_resolve_path(struct inode *inode,
+		const unsigned char *path, struct exfat_chain *dir,
+		struct exfat_uni_name *uni)
+{
+	return __exfat_resolve_path(inode, path, dir, uni, 0);
+}
+
+static inline int exfat_resolve_path_for_lookup(struct inode *inode,
+		const unsigned char *path, struct exfat_chain *dir,
+		struct exfat_uni_name *uni)
+{
+	return __exfat_resolve_path(inode, path, dir, uni, 1);
+}
+
+static inline loff_t exfat_make_i_pos(struct exfat_dir_entry *info)
+{
+	return ((loff_t) info->dir.dir << 32) | (info->entry & 0xffffffff);
+}
+
+static int exfat_add_entry(struct inode *inode, const char *path,
+		struct exfat_chain *p_dir, unsigned int type,
+		struct exfat_dir_entry *info)
+{
+	int ret, dentry, num_entries;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_uni_name uniname;
+	struct exfat_chain clu;
+	int clu_size = 0;
+	unsigned int start_clu = EXFAT_FREE_CLUSTER;
+
+	ret = exfat_resolve_path(inode, path, p_dir, &uniname);
+	if (ret)
+		goto out;
+
+	num_entries = exfat_calc_num_entries(&uniname);
+	if (num_entries < 0) {
+		ret = num_entries;
+		goto out;
+	}
+
+	/* exfat_find_empty_entry must be called before alloc_cluster() */
+	dentry = exfat_find_empty_entry(inode, p_dir, num_entries);
+	if (dentry < 0) {
+		ret = dentry; /* -EIO or -ENOSPC */
+		goto out;
+	}
+
+	if (type == TYPE_DIR) {
+		ret = exfat_alloc_new_dir(inode, &clu);
+		if (ret)
+			goto out;
+		start_clu = clu.dir;
+		clu_size = sbi->cluster_size;
+	}
+
+	/* update the directory entry */
+	/* fill the dos name directory entry information of the created file.
+	 * the first cluster is not determined yet. (0)
+	 */
+	ret = exfat_init_dir_entry(inode, p_dir, dentry, type,
+		start_clu, clu_size);
+	if (ret)
+		goto out;
+
+	ret = exfat_init_ext_entry(inode, p_dir, dentry, num_entries, &uniname);
+	if (ret)
+		goto out;
+
+	memcpy(&info->dir, p_dir, sizeof(struct exfat_chain));
+	info->entry = dentry;
+	info->flags = ALLOC_NO_FAT_CHAIN;
+	info->type = type;
+
+	if (type == TYPE_FILE) {
+		info->attr = ATTR_ARCHIVE;
+		info->start_clu = EXFAT_EOF_CLUSTER;
+		info->size = 0;
+		info->num_subdirs = 0;
+	} else {
+		int count;
+		struct exfat_chain cdir;
+
+		info->attr = ATTR_SUBDIR;
+		info->start_clu = start_clu;
+		info->size = clu_size;
+
+		exfat_chain_set(&cdir, info->start_clu,
+			EXFAT_B_TO_CLU(info->size, sbi), info->flags);
+		count = exfat_count_dir_entries(sb, &cdir);
+		if (count < 0)
+			return -EIO;
+		info->num_subdirs = count + EXFAT_MIN_SUBDIR;
+	}
+	memset(&info->crtime, 0, sizeof(info->crtime));
+	memset(&info->mtime, 0, sizeof(info->mtime));
+	memset(&info->atime, 0, sizeof(info->atime));
+out:
+	return ret;
+}
+
+static int exfat_create(struct inode *dir, struct dentry *dentry, umode_t mode,
+		bool excl)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode;
+	struct exfat_chain cdir;
+	struct exfat_dir_entry info;
+	loff_t i_pos;
+	int err;
+
+	mutex_lock(&EXFAT_SB(sb)->s_lock);
+	exfat_set_vol_flags(sb, VOL_DIRTY);
+	err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_FILE,
+		&info);
+	exfat_set_vol_flags(sb, VOL_CLEAN);
+	if (err)
+		goto unlock;
+
+	inode_inc_iversion(dir);
+	dir->i_ctime = dir->i_mtime = current_time(dir);
+	if (IS_DIRSYNC(dir))
+		exfat_sync_inode(dir);
+	else
+		mark_inode_dirty(dir);
+
+	i_pos = exfat_make_i_pos(&info);
+	inode = exfat_build_inode(sb, &info, i_pos);
+	if (IS_ERR(inode))
+		goto unlock;
+
+	inode_inc_iversion(inode);
+	inode->i_mtime = inode->i_atime = inode->i_ctime =
+		EXFAT_I(inode)->i_crtime = current_time(inode);
+	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
+
+	d_instantiate(dentry, inode);
+unlock:
+	mutex_unlock(&EXFAT_SB(sb)->s_lock);
+	return err;
+}
+
+/* lookup a file */
+static int exfat_find(struct inode *dir, struct qstr *qname,
+		struct exfat_dir_entry *info)
+{
+	int ret, dentry, num_entries, count;
+	struct exfat_chain cdir;
+	struct exfat_uni_name uni_name;
+	struct exfat_dentry *ep, *ep2;
+	struct exfat_entry_set_cache *es = NULL;
+	struct super_block *sb = dir->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_inode_info *ei = EXFAT_I(dir);
+
+	if (qname->len == 0)
+		return -ENOENT;
+
+	/* check the validity of directory name in the given pathname */
+	ret = exfat_resolve_path_for_lookup(dir, qname->name, &cdir, &uni_name);
+	if (ret)
+		return ret;
+
+	num_entries = exfat_calc_num_entries(&uni_name);
+	if (num_entries < 0)
+		return num_entries;
+
+	/* check the validation of hint_stat and initialize it if required */
+	if (ei->version != (inode_peek_iversion_raw(dir) & 0xffffffff)) {
+		ei->hint_stat.clu = cdir.dir;
+		ei->hint_stat.eidx = 0;
+		ei->version = (inode_peek_iversion_raw(dir) & 0xffffffff);
+		ei->hint_femp.eidx = EXFAT_HINT_NONE;
+	}
+
+	/* search the file name for directories */
+	dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name,
+			num_entries, TYPE_ALL);
+
+	if ((dentry < 0) && (dentry != -EEXIST))
+		return dentry; /* -error value */
+
+	memcpy(&info->dir, &cdir.dir, sizeof(struct exfat_chain));
+	info->entry = dentry;
+	info->num_subdirs = 0;
+
+	/* root directory itself */
+	if (unlikely(dentry == -EEXIST)) {
+		int num_clu = 0;
+
+		info->type = TYPE_DIR;
+		info->attr = ATTR_SUBDIR;
+		info->flags = ALLOC_FAT_CHAIN;
+		info->start_clu = sbi->root_dir;
+		memset(&info->crtime, 0, sizeof(info->crtime));
+		memset(&info->mtime, 0, sizeof(info->mtime));
+		memset(&info->atime, 0, sizeof(info->atime));
+
+		exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
+		if (exfat_count_num_clusters(sb, &cdir, &num_clu))
+			return -EIO;
+		info->size = num_clu << sbi->cluster_size_bits;
+
+		count = exfat_count_dir_entries(sb, &cdir);
+		if (count < 0)
+			return -EIO;
+
+		info->num_subdirs = count;
+	} else {
+		es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES, &ep);
+		if (!es)
+			return -EIO;
+		ep2 = ep + 1;
+
+		info->type = exfat_get_entry_type(ep);
+		info->attr = le16_to_cpu(ep->dentry.file.attr);
+		info->size = le64_to_cpu(ep2->dentry.stream.valid_size);
+		if ((info->type == TYPE_FILE) && (info->size == 0)) {
+			info->flags = ALLOC_NO_FAT_CHAIN;
+			info->start_clu = EXFAT_EOF_CLUSTER;
+		} else {
+			info->flags = ep2->dentry.stream.flags;
+			info->start_clu =
+				le32_to_cpu(ep2->dentry.stream.start_clu);
+		}
+
+		if (ei->start_clu == EXFAT_FREE_CLUSTER) {
+			exfat_fs_error(sb,
+				"non-zero size file starts with zero cluster (size : %llu, p_dir : %u, entry : 0x%08x)",
+				i_size_read(dir), ei->dir.dir, ei->entry);
+			return -EIO;
+		}
+
+		exfat_get_entry_time(sbi, &info->crtime,
+				ep->dentry.file.create_tz,
+				ep->dentry.file.create_time,
+				ep->dentry.file.create_date,
+				ep->dentry.file.create_time_ms);
+		exfat_get_entry_time(sbi, &info->mtime,
+				ep->dentry.file.modify_tz,
+				ep->dentry.file.modify_time,
+				ep->dentry.file.modify_date,
+				ep->dentry.file.modify_time_ms);
+		exfat_get_entry_time(sbi, &info->atime,
+				ep->dentry.file.access_tz,
+				ep->dentry.file.access_time,
+				ep->dentry.file.access_date,
+				0);
+		kfree(es);
+
+		if (info->type == TYPE_DIR) {
+			exfat_chain_set(&cdir, info->start_clu,
+				EXFAT_B_TO_CLU(info->size, sbi), info->flags);
+			count = exfat_count_dir_entries(sb, &cdir);
+			if (count < 0)
+				return -EIO;
+
+			info->num_subdirs = count + EXFAT_MIN_SUBDIR;
+		}
+	}
+	return 0;
+}
+
+static int exfat_d_anon_disconn(struct dentry *dentry)
+{
+	return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED);
+}
+
+static struct dentry *exfat_lookup(struct inode *dir, struct dentry *dentry,
+		unsigned int flags)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode;
+	struct dentry *alias;
+	struct exfat_dir_entry info;
+	int err;
+	loff_t i_pos;
+	mode_t i_mode;
+
+	mutex_lock(&EXFAT_SB(sb)->s_lock);
+	err = exfat_find(dir, &dentry->d_name, &info);
+	if (err) {
+		if (err == -ENOENT) {
+			inode = NULL;
+			goto out;
+		}
+		goto unlock;
+	}
+
+	i_pos = exfat_make_i_pos(&info);
+	inode = exfat_build_inode(sb, &info, i_pos);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto unlock;
+	}
+
+	i_mode = inode->i_mode;
+	alias = d_find_alias(inode);
+
+	/*
+	 * Checking "alias->d_parent == dentry->d_parent" to make sure
+	 * FS is not corrupted (especially double linked dir).
+	 */
+	if (alias && alias->d_parent == dentry->d_parent &&
+			!exfat_d_anon_disconn(alias)) {
+
+		/*
+		 * Unhashed alias is able to exist because of revalidate()
+		 * called by lookup_fast. You can easily make this status
+		 * by calling create and lookup concurrently
+		 * In such case, we reuse an alias instead of new dentry
+		 */
+		if (d_unhashed(alias)) {
+			WARN_ON(alias->d_name.hash_len !=
+				dentry->d_name.hash_len);
+			exfat_msg(sb, KERN_INFO,
+				"rehashed a dentry(%p) in read lookup", alias);
+			d_drop(dentry);
+			d_rehash(alias);
+		} else if (!S_ISDIR(i_mode)) {
+			/*
+			 * This inode has non anonymous-DCACHE_DISCONNECTED
+			 * dentry. This means, the user did ->lookup() by an
+			 * another name (longname vs 8.3 alias of it) in past.
+			 *
+			 * Switch to new one for reason of locality if possible.
+			 */
+			d_move(alias, dentry);
+		}
+		iput(inode);
+		mutex_unlock(&EXFAT_SB(sb)->s_lock);
+		return alias;
+	}
+	dput(alias);
+out:
+	mutex_unlock(&EXFAT_SB(sb)->s_lock);
+	if (!inode)
+		exfat_d_version_set(dentry, inode_query_iversion(dir));
+
+	return d_splice_alias(inode, dentry);
+unlock:
+	mutex_unlock(&EXFAT_SB(sb)->s_lock);
+	return ERR_PTR(err);
+}
+
+/* remove an entry, BUT don't truncate */
+static int exfat_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct exfat_chain cdir;
+	struct exfat_dentry *ep;
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode = dentry->d_inode;
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	struct buffer_head *bh;
+	sector_t sector;
+	int num_entries, entry, err = 0;
+
+	mutex_lock(&EXFAT_SB(sb)->s_lock);
+	exfat_chain_dup(&cdir, &ei->dir);
+	entry = ei->entry;
+	if (ei->dir.dir == DIR_DELETED) {
+		exfat_msg(sb, KERN_ERR, "abnormal access to deleted dentry");
+		err = -ENOENT;
+		goto unlock;
+	}
+
+	ep = exfat_get_dentry(sb, &cdir, entry, &bh, &sector);
+	if (!ep) {
+		err = -EIO;
+		goto unlock;
+	}
+	num_entries = exfat_count_ext_entries(sb, &cdir, entry, ep);
+	if (num_entries < 0) {
+		err = -EIO;
+		brelse(bh);
+		goto unlock;
+	}
+	num_entries++;
+	brelse(bh);
+
+	exfat_set_vol_flags(sb, VOL_DIRTY);
+	/* update the directory entry */
+	if (exfat_remove_entries(dir, &cdir, entry, 0, num_entries)) {
+		err = -EIO;
+		goto unlock;
+	}
+
+	/* This doesn't modify ei */
+	ei->dir.dir = DIR_DELETED;
+	exfat_set_vol_flags(sb, VOL_CLEAN);
+
+	inode_inc_iversion(dir);
+	dir->i_mtime = dir->i_atime = current_time(dir);
+	if (IS_DIRSYNC(dir))
+		exfat_sync_inode(dir);
+	else
+		mark_inode_dirty(dir);
+
+	clear_nlink(inode);
+	inode->i_mtime = inode->i_atime = current_time(inode);
+	exfat_unhash_inode(inode);
+	exfat_d_version_set(dentry, inode_query_iversion(dir));
+unlock:
+	mutex_unlock(&EXFAT_SB(sb)->s_lock);
+	return err;
+}
+
+static int exfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode;
+	struct exfat_dir_entry info;
+	struct exfat_chain cdir;
+	loff_t i_pos;
+	int err;
+
+	mutex_lock(&EXFAT_SB(sb)->s_lock);
+	exfat_set_vol_flags(sb, VOL_DIRTY);
+	err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_DIR,
+		&info);
+	exfat_set_vol_flags(sb, VOL_CLEAN);
+	if (err)
+		goto unlock;
+
+	inode_inc_iversion(dir);
+	dir->i_ctime = dir->i_mtime = current_time(dir);
+	if (IS_DIRSYNC(dir))
+		exfat_sync_inode(dir);
+	else
+		mark_inode_dirty(dir);
+	inc_nlink(dir);
+
+	i_pos = exfat_make_i_pos(&info);
+	inode = exfat_build_inode(sb, &info, i_pos);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto unlock;
+	}
+
+	inode_inc_iversion(inode);
+	inode->i_mtime = inode->i_atime = inode->i_ctime =
+		EXFAT_I(inode)->i_crtime = current_time(inode);
+	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
+
+	d_instantiate(dentry, inode);
+
+unlock:
+	mutex_unlock(&EXFAT_SB(sb)->s_lock);
+	return err;
+}
+
+static int exfat_check_dir_empty(struct super_block *sb,
+		struct exfat_chain *p_dir)
+{
+	int i, dentries_per_clu;
+	unsigned int type;
+	struct exfat_chain clu;
+	struct exfat_dentry *ep;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct buffer_head *bh;
+
+	dentries_per_clu = sbi->dentries_per_clu;
+
+	exfat_chain_dup(&clu, p_dir);
+
+	while (clu.dir != EXFAT_EOF_CLUSTER) {
+		for (i = 0; i < dentries_per_clu; i++) {
+			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
+			if (!ep)
+				return -EIO;
+			type = exfat_get_entry_type(ep);
+			brelse(bh);
+			if (type == TYPE_UNUSED)
+				return 0;
+
+			if (type != TYPE_FILE && type != TYPE_DIR)
+				continue;
+
+			return -ENOTEMPTY;
+		}
+
+		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
+			if (--clu.size > 0)
+				clu.dir++;
+			else
+				clu.dir = EXFAT_EOF_CLUSTER;
+		} else {
+			if (exfat_get_next_cluster(sb, &(clu.dir)))
+				return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	struct exfat_dentry *ep;
+	struct exfat_chain cdir, clu_to_free;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_inode_info *ei = EXFAT_I(inode);
+	struct buffer_head *bh;
+	sector_t sector;
+	int num_entries, entry, err;
+
+	mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
+
+	exfat_chain_dup(&cdir, &ei->dir);
+	entry = ei->entry;
+
+	if (ei->dir.dir == DIR_DELETED) {
+		exfat_msg(sb, KERN_ERR, "abnormal access to deleted dentry");
+		err = -ENOENT;
+		goto unlock;
+	}
+
+	exfat_set_vol_flags(sb, VOL_DIRTY);
+	exfat_chain_set(&clu_to_free, ei->start_clu,
+		EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi), ei->flags);
+
+	err = exfat_check_dir_empty(sb, &clu_to_free);
+	if (err) {
+		if (err == -EIO)
+			exfat_msg(sb, KERN_ERR,
+				"failed to exfat_check_dir_empty : err(%d)",
+				err);
+		goto unlock;
+	}
+
+	ep = exfat_get_dentry(sb, &cdir, entry, &bh, &sector);
+	if (!ep) {
+		err = -EIO;
+		goto unlock;
+	}
+
+	num_entries = exfat_count_ext_entries(sb, &cdir, entry, ep);
+	if (num_entries < 0) {
+		err = -EIO;
+		brelse(bh);
+		goto unlock;
+	}
+	num_entries++;
+	brelse(bh);
+
+	err = exfat_remove_entries(dir, &cdir, entry, 0, num_entries);
+	if (err) {
+		exfat_msg(sb, KERN_ERR,
+				"failed to exfat_remove_entries : err(%d)",
+				err);
+		goto unlock;
+	}
+	ei->dir.dir = DIR_DELETED;
+	exfat_set_vol_flags(sb, VOL_CLEAN);
+
+	inode_inc_iversion(dir);
+	dir->i_mtime = dir->i_atime = current_time(dir);
+	if (IS_DIRSYNC(dir))
+		exfat_sync_inode(dir);
+	else
+		mark_inode_dirty(dir);
+	drop_nlink(dir);
+
+	clear_nlink(inode);
+	inode->i_mtime = inode->i_atime = current_time(inode);
+	exfat_unhash_inode(inode);
+	exfat_d_version_set(dentry, inode_query_iversion(dir));
+unlock:
+	mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
+	return err;
+}
+
+static int exfat_rename_file(struct inode *inode, struct exfat_chain *p_dir,
+		int oldentry, struct exfat_uni_name *p_uniname,
+		struct exfat_inode_info *ei)
+{
+	int ret, num_old_entries, num_new_entries;
+	sector_t sector_old, sector_new;
+	struct exfat_dentry *epold, *epnew;
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *new_bh, *old_bh;
+	int sync = IS_DIRSYNC(inode);
+
+	epold = exfat_get_dentry(sb, p_dir, oldentry, &old_bh, &sector_old);
+	if (!epold)
+		return -EIO;
+
+	num_old_entries = exfat_count_ext_entries(sb, p_dir, oldentry, epold);
+	if (num_old_entries < 0)
+		return -EIO;
+	num_old_entries++;
+
+	num_new_entries = exfat_calc_num_entries(p_uniname);
+	if (num_new_entries < 0)
+		return num_new_entries;
+
+	if (num_old_entries < num_new_entries) {
+		int newentry;
+
+		newentry =
+			exfat_find_empty_entry(inode, p_dir, num_new_entries);
+		if (newentry < 0)
+			return newentry; /* -EIO or -ENOSPC */
+
+		epnew = exfat_get_dentry(sb, p_dir, newentry, &new_bh,
+			&sector_new);
+		if (!epnew)
+			return -EIO;
+
+		memcpy(epnew, epold, DENTRY_SIZE);
+		if (exfat_get_entry_type(epnew) == TYPE_FILE) {
+			epnew->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
+			ei->attr |= ATTR_ARCHIVE;
+		}
+		exfat_update_bh(sb, new_bh, sync);
+		brelse(old_bh);
+		brelse(new_bh);
+
+		epold = exfat_get_dentry(sb, p_dir, oldentry + 1, &old_bh,
+			&sector_old);
+		epnew = exfat_get_dentry(sb, p_dir, newentry + 1, &new_bh,
+			&sector_new);
+		if (!epold || !epnew)
+			return -EIO;
+
+		memcpy(epnew, epold, DENTRY_SIZE);
+		exfat_update_bh(sb, new_bh, sync);
+		brelse(old_bh);
+		brelse(new_bh);
+
+		ret = exfat_init_ext_entry(inode, p_dir, newentry,
+			num_new_entries, p_uniname);
+		if (ret)
+			return ret;
+
+		exfat_remove_entries(inode, p_dir, oldentry, 0,
+			num_old_entries);
+		ei->entry = newentry;
+	} else {
+		if (exfat_get_entry_type(epold) == TYPE_FILE) {
+			epold->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
+			ei->attr |= ATTR_ARCHIVE;
+		}
+		exfat_update_bh(sb, old_bh, sync);
+		brelse(old_bh);
+		ret = exfat_init_ext_entry(inode, p_dir, oldentry,
+			num_new_entries, p_uniname);
+		if (ret)
+			return ret;
+
+		exfat_remove_entries(inode, p_dir, oldentry, num_new_entries,
+			num_old_entries);
+	}
+	return 0;
+}
+
+static int exfat_move_file(struct inode *inode, struct exfat_chain *p_olddir,
+		int oldentry, struct exfat_chain *p_newdir,
+		struct exfat_uni_name *p_uniname, struct exfat_inode_info *ei)
+{
+	int ret, newentry, num_new_entries, num_old_entries;
+	sector_t sector_mov, sector_new;
+	struct exfat_dentry *epmov, *epnew;
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *mov_bh, *new_bh;
+
+	epmov = exfat_get_dentry(sb, p_olddir, oldentry, &mov_bh, &sector_mov);
+	if (!epmov)
+		return -EIO;
+
+	/* check if the source and target directory is the same */
+	if (exfat_get_entry_type(epmov) == TYPE_DIR &&
+	    le32_to_cpu(epmov->dentry.stream.start_clu) == p_newdir->dir)
+		return -EINVAL;
+
+	num_old_entries = exfat_count_ext_entries(sb, p_olddir, oldentry,
+		epmov);
+	if (num_old_entries < 0)
+		return -EIO;
+	num_old_entries++;
+
+	num_new_entries = exfat_calc_num_entries(p_uniname);
+	if (num_new_entries < 0)
+		return num_new_entries;
+
+	newentry = exfat_find_empty_entry(inode, p_newdir, num_new_entries);
+	if (newentry < 0)
+		return newentry; /* -EIO or -ENOSPC */
+
+	epnew = exfat_get_dentry(sb, p_newdir, newentry, &new_bh, &sector_new);
+	if (!epnew)
+		return -EIO;
+
+	memcpy(epnew, epmov, DENTRY_SIZE);
+	if (exfat_get_entry_type(epnew) == TYPE_FILE) {
+		epnew->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
+		ei->attr |= ATTR_ARCHIVE;
+	}
+	exfat_update_bh(sb, new_bh, IS_DIRSYNC(inode));
+	brelse(mov_bh);
+	brelse(new_bh);
+
+	epmov = exfat_get_dentry(sb, p_olddir, oldentry + 1, &mov_bh,
+		&sector_mov);
+	epnew = exfat_get_dentry(sb, p_newdir, newentry + 1, &new_bh,
+		&sector_new);
+	if (!epmov || !epnew)
+		return -EIO;
+
+	memcpy(epnew, epmov, DENTRY_SIZE);
+	exfat_update_bh(sb, new_bh, IS_DIRSYNC(inode));
+	brelse(mov_bh);
+	brelse(new_bh);
+
+	ret = exfat_init_ext_entry(inode, p_newdir, newentry, num_new_entries,
+		p_uniname);
+	if (ret)
+		return ret;
+
+	exfat_remove_entries(inode, p_olddir, oldentry, 0, num_old_entries);
+
+	exfat_chain_set(&ei->dir, p_newdir->dir, p_newdir->size,
+		p_newdir->flags);
+
+	ei->entry = newentry;
+	return 0;
+}
+
+static void exfat_update_parent_info(struct exfat_inode_info *ei,
+		struct inode *parent_inode)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(parent_inode->i_sb);
+	struct exfat_inode_info *parent_ei = EXFAT_I(parent_inode);
+	loff_t parent_isize = i_size_read(parent_inode);
+
+	/*
+	 * the problem that struct exfat_inode_info caches wrong parent info.
+	 *
+	 * because of flag-mismatch of ei->dir,
+	 * there is abnormal traversing cluster chain.
+	 */
+	if (unlikely(parent_ei->flags != ei->dir.flags ||
+		     parent_isize != EXFAT_CLU_TO_B(ei->dir.size, sbi) ||
+		     parent_ei->start_clu != ei->dir.dir)) {
+		exfat_chain_set(&ei->dir, parent_ei->start_clu,
+			EXFAT_B_TO_CLU_ROUND_UP(parent_isize, sbi),
+			parent_ei->flags);
+	}
+}
+
+/* rename or move a old file into a new file */
+static int __exfat_rename(struct inode *old_parent_inode,
+		struct exfat_inode_info *ei, struct inode *new_parent_inode,
+		struct dentry *new_dentry)
+{
+	int ret;
+	int dentry;
+	struct exfat_chain olddir, newdir;
+	struct exfat_chain *p_dir = NULL;
+	struct exfat_uni_name uni_name;
+	struct exfat_dentry *ep;
+	struct super_block *sb = old_parent_inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	const unsigned char *new_path = new_dentry->d_name.name;
+	struct inode *new_inode = new_dentry->d_inode;
+	int num_entries;
+	struct exfat_inode_info *new_ei = NULL;
+	unsigned int new_entry_type = TYPE_UNUSED;
+	int new_entry = 0;
+	struct buffer_head *old_bh, *new_bh = NULL;
+
+	/* check the validity of pointer parameters */
+	if (new_path == NULL || strlen(new_path) == 0)
+		return -EINVAL;
+
+	if (ei->dir.dir == DIR_DELETED) {
+		exfat_msg(sb, KERN_ERR,
+				"abnormal access to deleted source dentry");
+		return -ENOENT;
+	}
+
+	exfat_update_parent_info(ei, old_parent_inode);
+
+	exfat_chain_dup(&olddir, &ei->dir);
+	dentry = ei->entry;
+
+	ep = exfat_get_dentry(sb, &olddir, dentry, &old_bh, NULL);
+	if (!ep) {
+		ret = -EIO;
+		goto out;
+	}
+	brelse(old_bh);
+
+	/* check whether new dir is existing directory and empty */
+	if (new_inode) {
+		ret = -EIO;
+		new_ei = EXFAT_I(new_inode);
+
+		if (new_ei->dir.dir == DIR_DELETED) {
+			exfat_msg(sb, KERN_ERR,
+				"abnormal access to deleted target dentry");
+			goto out;
+		}
+
+		exfat_update_parent_info(new_ei, new_parent_inode);
+
+		p_dir = &(new_ei->dir);
+		new_entry = new_ei->entry;
+		ep = exfat_get_dentry(sb, p_dir, new_entry, &new_bh, NULL);
+		if (!ep)
+			goto out;
+
+		new_entry_type = exfat_get_entry_type(ep);
+		brelse(new_bh);
+
+		/* if new_inode exists, update ei */
+		if (new_entry_type == TYPE_DIR) {
+			struct exfat_chain new_clu;
+
+			new_clu.dir = new_ei->start_clu;
+			new_clu.size =
+				EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
+				sbi);
+			new_clu.flags = new_ei->flags;
+
+			ret = exfat_check_dir_empty(sb, &new_clu);
+			if (ret)
+				goto out;
+		}
+	}
+
+	/* check the validity of directory name in the given new pathname */
+	ret = exfat_resolve_path(new_parent_inode, new_path, &newdir,
+			&uni_name);
+	if (ret)
+		goto out;
+
+	exfat_set_vol_flags(sb, VOL_DIRTY);
+
+	if (olddir.dir == newdir.dir)
+		ret = exfat_rename_file(new_parent_inode, &olddir, dentry,
+				&uni_name, ei);
+	else
+		ret = exfat_move_file(new_parent_inode, &olddir, dentry,
+				&newdir, &uni_name, ei);
+
+	if (!ret && new_inode) {
+		/* delete entries of new_dir */
+		ep = exfat_get_dentry(sb, p_dir, new_entry, &new_bh, NULL);
+		if (!ep) {
+			ret = -EIO;
+			goto del_out;
+		}
+
+		num_entries = exfat_count_ext_entries(sb, p_dir, new_entry, ep);
+		if (num_entries < 0) {
+			ret = -EIO;
+			goto del_out;
+		}
+		brelse(new_bh);
+
+		if (exfat_remove_entries(new_inode, p_dir, new_entry, 0,
+				num_entries + 1)) {
+			ret = -EIO;
+			goto del_out;
+		}
+
+		/* Free the clusters if new_inode is a dir(as if exfat_rmdir) */
+		if (new_entry_type == TYPE_DIR) {
+			/* new_ei, new_clu_to_free */
+			struct exfat_chain new_clu_to_free;
+
+			exfat_chain_set(&new_clu_to_free, new_ei->start_clu,
+				EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
+				sbi), new_ei->flags);
+
+			if (exfat_free_cluster(new_inode, &new_clu_to_free)) {
+				/* just set I/O error only */
+				ret = -EIO;
+			}
+
+			i_size_write(new_inode, 0);
+			new_ei->start_clu = EXFAT_EOF_CLUSTER;
+			new_ei->flags = ALLOC_NO_FAT_CHAIN;
+		}
+del_out:
+		/* Update new_inode ei
+		 * Prevent syncing removed new_inode
+		 * (new_ei is already initialized above code ("if (new_inode)")
+		 */
+		new_ei->dir.dir = DIR_DELETED;
+	}
+	exfat_set_vol_flags(sb, VOL_CLEAN);
+out:
+	return ret;
+}
+
+static int exfat_rename(struct inode *old_dir, struct dentry *old_dentry,
+		struct inode *new_dir, struct dentry *new_dentry,
+		unsigned int flags)
+{
+	struct inode *old_inode, *new_inode;
+	struct super_block *sb = old_dir->i_sb;
+	loff_t i_pos;
+	int err;
+
+	/*
+	 * The VFS already checks for existence, so for local filesystems
+	 * the RENAME_NOREPLACE implementation is equivalent to plain rename.
+	 * Don't support any other flags
+	 */
+	if (flags & ~RENAME_NOREPLACE)
+		return -EINVAL;
+
+	mutex_lock(&EXFAT_SB(sb)->s_lock);
+	old_inode = old_dentry->d_inode;
+	new_inode = new_dentry->d_inode;
+
+	err = __exfat_rename(old_dir, EXFAT_I(old_inode), new_dir, new_dentry);
+	if (err)
+		goto unlock;
+
+	inode_inc_iversion(new_dir);
+	new_dir->i_ctime = new_dir->i_mtime = new_dir->i_atime =
+		EXFAT_I(new_dir)->i_crtime = current_time(new_dir);
+	if (IS_DIRSYNC(new_dir))
+		exfat_sync_inode(new_dir);
+	else
+		mark_inode_dirty(new_dir);
+
+	i_pos = ((loff_t)EXFAT_I(old_inode)->dir.dir << 32) |
+		(EXFAT_I(old_inode)->entry & 0xffffffff);
+	exfat_unhash_inode(old_inode);
+	exfat_hash_inode(old_inode, i_pos);
+	if (IS_DIRSYNC(new_dir))
+		exfat_sync_inode(old_inode);
+	else
+		mark_inode_dirty(old_inode);
+
+	if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
+		drop_nlink(old_dir);
+		if (!new_inode)
+			inc_nlink(new_dir);
+	}
+
+	inode_inc_iversion(old_dir);
+	old_dir->i_ctime = old_dir->i_mtime = current_time(old_dir);
+	if (IS_DIRSYNC(old_dir))
+		exfat_sync_inode(old_dir);
+	else
+		mark_inode_dirty(old_dir);
+
+	if (new_inode) {
+		exfat_unhash_inode(new_inode);
+
+		/* skip drop_nlink if new_inode already has been dropped */
+		if (new_inode->i_nlink) {
+			drop_nlink(new_inode);
+			if (S_ISDIR(new_inode->i_mode))
+				drop_nlink(new_inode);
+		} else {
+			exfat_msg(sb, KERN_WARNING,
+					"abnormal access to an inode dropped");
+			WARN_ON(new_inode->i_nlink == 0);
+		}
+		new_inode->i_ctime = EXFAT_I(new_inode)->i_crtime =
+			current_time(new_inode);
+	}
+
+unlock:
+	mutex_unlock(&EXFAT_SB(sb)->s_lock);
+	return err;
+}
+
+const struct inode_operations exfat_dir_inode_operations = {
+	.create		= exfat_create,
+	.lookup		= exfat_lookup,
+	.unlink		= exfat_unlink,
+	.mkdir		= exfat_mkdir,
+	.rmdir		= exfat_rmdir,
+	.rename		= exfat_rename,
+	.setattr	= exfat_setattr,
+	.getattr	= exfat_getattr,
+};

fs/exfat/nls.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+#include <asm/unaligned.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+
+/* Upcase tabel macro */
+#define EXFAT_NUM_UPCASE	(2918)
+#define UTBL_COUNT		(0x10000)
+
+/*
+ * Upcase table in compressed format (7.2.5.1 Recommended Up-case Table
+ * in exfat specification, See:
+ * https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification).
+ */
+static const unsigned short uni_def_upcase[EXFAT_NUM_UPCASE] = {
+	0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
+	0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
+	0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
+	0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f,
+	0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
+	0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
+	0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
+	0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
+	0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
+	0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
+	0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
+	0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
+	0x0060, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
+	0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
+	0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
+	0x0058, 0x0059, 0x005a, 0x007b, 0x007c, 0x007d, 0x007e, 0x007f,
+	0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087,
+	0x0088, 0x0089, 0x008a, 0x008b, 0x008c, 0x008d, 0x008e, 0x008f,
+	0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097,
+	0x0098, 0x0099, 0x009a, 0x009b, 0x009c, 0x009d, 0x009e, 0x009f,
+	0x00a0, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
+	0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x00ad, 0x00ae, 0x00af,
+	0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
+	0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
+	0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
+	0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
+	0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
+	0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
+	0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
+	0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
+	0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00f7,
+	0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x0178,
+	0x0100, 0x0100, 0x0102, 0x0102, 0x0104, 0x0104, 0x0106, 0x0106,
+	0x0108, 0x0108, 0x010a, 0x010a, 0x010c, 0x010c, 0x010e, 0x010e,
+	0x0110, 0x0110, 0x0112, 0x0112, 0x0114, 0x0114, 0x0116, 0x0116,
+	0x0118, 0x0118, 0x011a, 0x011a, 0x011c, 0x011c, 0x011e, 0x011e,
+	0x0120, 0x0120, 0x0122, 0x0122, 0x0124, 0x0124, 0x0126, 0x0126,
+	0x0128, 0x0128, 0x012a, 0x012a, 0x012c, 0x012c, 0x012e, 0x012e,
+	0x0130, 0x0131, 0x0132, 0x0132, 0x0134, 0x0134, 0x0136, 0x0136,
+	0x0138, 0x0139, 0x0139, 0x013b, 0x013b, 0x013d, 0x013d, 0x013f,
+	0x013f, 0x0141, 0x0141, 0x0143, 0x0143, 0x0145, 0x0145, 0x0147,
+	0x0147, 0x0149, 0x014a, 0x014a, 0x014c, 0x014c, 0x014e, 0x014e,
+	0x0150, 0x0150, 0x0152, 0x0152, 0x0154, 0x0154, 0x0156, 0x0156,
+	0x0158, 0x0158, 0x015a, 0x015a, 0x015c, 0x015c, 0x015e, 0x015e,
+	0x0160, 0x0160, 0x0162, 0x0162, 0x0164, 0x0164, 0x0166, 0x0166,
+	0x0168, 0x0168, 0x016a, 0x016a, 0x016c, 0x016c, 0x016e, 0x016e,
+	0x0170, 0x0170, 0x0172, 0x0172, 0x0174, 0x0174, 0x0176, 0x0176,
+	0x0178, 0x0179, 0x0179, 0x017b, 0x017b, 0x017d, 0x017d, 0x017f,
+	0x0243, 0x0181, 0x0182, 0x0182, 0x0184, 0x0184, 0x0186, 0x0187,
+	0x0187, 0x0189, 0x018a, 0x018b, 0x018b, 0x018d, 0x018e, 0x018f,
+	0x0190, 0x0191, 0x0191, 0x0193, 0x0194, 0x01f6, 0x0196, 0x0197,
+	0x0198, 0x0198, 0x023d, 0x019b, 0x019c, 0x019d, 0x0220, 0x019f,
+	0x01a0, 0x01a0, 0x01a2, 0x01a2, 0x01a4, 0x01a4, 0x01a6, 0x01a7,
+	0x01a7, 0x01a9, 0x01aa, 0x01ab, 0x01ac, 0x01ac, 0x01ae, 0x01af,
+	0x01af, 0x01b1, 0x01b2, 0x01b3, 0x01b3, 0x01b5, 0x01b5, 0x01b7,
+	0x01b8, 0x01b8, 0x01ba, 0x01bb, 0x01bc, 0x01bc, 0x01be, 0x01f7,
+	0x01c0, 0x01c1, 0x01c2, 0x01c3, 0x01c4, 0x01c5, 0x01c4, 0x01c7,
+	0x01c8, 0x01c7, 0x01ca, 0x01cb, 0x01ca, 0x01cd, 0x01cd, 0x01cf,
+	0x01cf, 0x01d1, 0x01d1, 0x01d3, 0x01d3, 0x01d5, 0x01d5, 0x01d7,
+	0x01d7, 0x01d9, 0x01d9, 0x01db, 0x01db, 0x018e, 0x01de, 0x01de,
+	0x01e0, 0x01e0, 0x01e2, 0x01e2, 0x01e4, 0x01e4, 0x01e6, 0x01e6,
+	0x01e8, 0x01e8, 0x01ea, 0x01ea, 0x01ec, 0x01ec, 0x01ee, 0x01ee,
+	0x01f0, 0x01f1, 0x01f2, 0x01f1, 0x01f4, 0x01f4, 0x01f6, 0x01f7,
+	0x01f8, 0x01f8, 0x01fa, 0x01fa, 0x01fc, 0x01fc, 0x01fe, 0x01fe,
+	0x0200, 0x0200, 0x0202, 0x0202, 0x0204, 0x0204, 0x0206, 0x0206,
+	0x0208, 0x0208, 0x020a, 0x020a, 0x020c, 0x020c, 0x020e, 0x020e,
+	0x0210, 0x0210, 0x0212, 0x0212, 0x0214, 0x0214, 0x0216, 0x0216,
+	0x0218, 0x0218, 0x021a, 0x021a, 0x021c, 0x021c, 0x021e, 0x021e,
+	0x0220, 0x0221, 0x0222, 0x0222, 0x0224, 0x0224, 0x0226, 0x0226,
+	0x0228, 0x0228, 0x022a, 0x022a, 0x022c, 0x022c, 0x022e, 0x022e,
+	0x0230, 0x0230, 0x0232, 0x0232, 0x0234, 0x0235, 0x0236, 0x0237,
+	0x0238, 0x0239, 0x2c65, 0x023b, 0x023b, 0x023d, 0x2c66, 0x023f,
+	0x0240, 0x0241, 0x0241, 0x0243, 0x0244, 0x0245, 0x0246, 0x0246,
+	0x0248, 0x0248, 0x024a, 0x024a, 0x024c, 0x024c, 0x024e, 0x024e,
+	0x0250, 0x0251, 0x0252, 0x0181, 0x0186, 0x0255, 0x0189, 0x018a,
+	0x0258, 0x018f, 0x025a, 0x0190, 0x025c, 0x025d, 0x025e, 0x025f,
+	0x0193, 0x0261, 0x0262, 0x0194, 0x0264, 0x0265, 0x0266, 0x0267,
+	0x0197, 0x0196, 0x026a, 0x2c62, 0x026c, 0x026d, 0x026e, 0x019c,
+	0x0270, 0x0271, 0x019d, 0x0273, 0x0274, 0x019f, 0x0276, 0x0277,
+	0x0278, 0x0279, 0x027a, 0x027b, 0x027c, 0x2c64, 0x027e, 0x027f,
+	0x01a6, 0x0281, 0x0282, 0x01a9, 0x0284, 0x0285, 0x0286, 0x0287,
+	0x01ae, 0x0244, 0x01b1, 0x01b2, 0x0245, 0x028d, 0x028e, 0x028f,
+	0x0290, 0x0291, 0x01b7, 0x0293, 0x0294, 0x0295, 0x0296, 0x0297,
+	0x0298, 0x0299, 0x029a, 0x029b, 0x029c, 0x029d, 0x029e, 0x029f,
+	0x02a0, 0x02a1, 0x02a2, 0x02a3, 0x02a4, 0x02a5, 0x02a6, 0x02a7,
+	0x02a8, 0x02a9, 0x02aa, 0x02ab, 0x02ac, 0x02ad, 0x02ae, 0x02af,
+	0x02b0, 0x02b1, 0x02b2, 0x02b3, 0x02b4, 0x02b5, 0x02b6, 0x02b7,
+	0x02b8, 0x02b9, 0x02ba, 0x02bb, 0x02bc, 0x02bd, 0x02be, 0x02bf,
+	0x02c0, 0x02c1, 0x02c2, 0x02c3, 0x02c4, 0x02c5, 0x02c6, 0x02c7,
+	0x02c8, 0x02c9, 0x02ca, 0x02cb, 0x02cc, 0x02cd, 0x02ce, 0x02cf,
+	0x02d0, 0x02d1, 0x02d2, 0x02d3, 0x02d4, 0x02d5, 0x02d6, 0x02d7,
+	0x02d8, 0x02d9, 0x02da, 0x02db, 0x02dc, 0x02dd, 0x02de, 0x02df,
+	0x02e0, 0x02e1, 0x02e2, 0x02e3, 0x02e4, 0x02e5, 0x02e6, 0x02e7,
+	0x02e8, 0x02e9, 0x02ea, 0x02eb, 0x02ec, 0x02ed, 0x02ee, 0x02ef,
+	0x02f0, 0x02f1, 0x02f2, 0x02f3, 0x02f4, 0x02f5, 0x02f6, 0x02f7,
+	0x02f8, 0x02f9, 0x02fa, 0x02fb, 0x02fc, 0x02fd, 0x02fe, 0x02ff,
+	0x0300, 0x0301, 0x0302, 0x0303, 0x0304, 0x0305, 0x0306, 0x0307,
+	0x0308, 0x0309, 0x030a, 0x030b, 0x030c, 0x030d, 0x030e, 0x030f,
+	0x0310, 0x0311, 0x0312, 0x0313, 0x0314, 0x0315, 0x0316, 0x0317,
+	0x0318, 0x0319, 0x031a, 0x031b, 0x031c, 0x031d, 0x031e, 0x031f,
+	0x0320, 0x0321, 0x0322, 0x0323, 0x0324, 0x0325, 0x0326, 0x0327,
+	0x0328, 0x0329, 0x032a, 0x032b, 0x032c, 0x032d, 0x032e, 0x032f,
+	0x0330, 0x0331, 0x0332, 0x0333, 0x0334, 0x0335, 0x0336, 0x0337,
+	0x0338, 0x0339, 0x033a, 0x033b, 0x033c, 0x033d, 0x033e, 0x033f,
+	0x0340, 0x0341, 0x0342, 0x0343, 0x0344, 0x0345, 0x0346, 0x0347,
+	0x0348, 0x0349, 0x034a, 0x034b, 0x034c, 0x034d, 0x034e, 0x034f,
+	0x0350, 0x0351, 0x0352, 0x0353, 0x0354, 0x0355, 0x0356, 0x0357,
+	0x0358, 0x0359, 0x035a, 0x035b, 0x035c, 0x035d, 0x035e, 0x035f,
+	0x0360, 0x0361, 0x0362, 0x0363, 0x0364, 0x0365, 0x0366, 0x0367,
+	0x0368, 0x0369, 0x036a, 0x036b, 0x036c, 0x036d, 0x036e, 0x036f,
+	0x0370, 0x0371, 0x0372, 0x0373, 0x0374, 0x0375, 0x0376, 0x0377,
+	0x0378, 0x0379, 0x037a, 0x03fd, 0x03fe, 0x03ff, 0x037e, 0x037f,
+	0x0380, 0x0381, 0x0382, 0x0383, 0x0384, 0x0385, 0x0386, 0x0387,
+	0x0388, 0x0389, 0x038a, 0x038b, 0x038c, 0x038d, 0x038e, 0x038f,
+	0x0390, 0x0391, 0x0392, 0x0393, 0x0394, 0x0395, 0x0396, 0x0397,
+	0x0398, 0x0399, 0x039a, 0x039b, 0x039c, 0x039d, 0x039e, 0x039f,
+	0x03a0, 0x03a1, 0x03a2, 0x03a3, 0x03a4, 0x03a5, 0x03a6, 0x03a7,
+	0x03a8, 0x03a9, 0x03aa, 0x03ab, 0x0386, 0x0388, 0x0389, 0x038a,
+	0x03b0, 0x0391, 0x0392, 0x0393, 0x0394, 0x0395, 0x0396, 0x0397,
+	0x0398, 0x0399, 0x039a, 0x039b, 0x039c, 0x039d, 0x039e, 0x039f,
+	0x03a0, 0x03a1, 0x03a3, 0x03a3, 0x03a4, 0x03a5, 0x03a6, 0x03a7,
+	0x03a8, 0x03a9, 0x03aa, 0x03ab, 0x038c, 0x038e, 0x038f, 0x03cf,
+	0x03d0, 0x03d1, 0x03d2, 0x03d3, 0x03d4, 0x03d5, 0x03d6, 0x03d7,
+	0x03d8, 0x03d8, 0x03da, 0x03da, 0x03dc, 0x03dc, 0x03de, 0x03de,
+	0x03e0, 0x03e0, 0x03e2, 0x03e2, 0x03e4, 0x03e4, 0x03e6, 0x03e6,
+	0x03e8, 0x03e8, 0x03ea, 0x03ea, 0x03ec, 0x03ec, 0x03ee, 0x03ee,
+	0x03f0, 0x03f1, 0x03f9, 0x03f3, 0x03f4, 0x03f5, 0x03f6, 0x03f7,
+	0x03f7, 0x03f9, 0x03fa, 0x03fa, 0x03fc, 0x03fd, 0x03fe, 0x03ff,
+	0x0400, 0x0401, 0x0402, 0x0403, 0x0404, 0x0405, 0x0406, 0x0407,
+	0x0408, 0x0409, 0x040a, 0x040b, 0x040c, 0x040d, 0x040e, 0x040f,
+	0x0410, 0x0411, 0x0412, 0x0413, 0x0414, 0x0415, 0x0416, 0x0417,
+	0x0418, 0x0419, 0x041a, 0x041b, 0x041c, 0x041d, 0x041e, 0x041f,
+	0x0420, 0x0421, 0x0422, 0x0423, 0x0424, 0x0425, 0x0426, 0x0427,
+	0x0428, 0x0429, 0x042a, 0x042b, 0x042c, 0x042d, 0x042e, 0x042f,
+	0x0410, 0x0411, 0x0412, 0x0413, 0x0414, 0x0415, 0x0416, 0x0417,
+	0x0418, 0x0419, 0x041a, 0x041b, 0x041c, 0x041d, 0x041e, 0x041f,
+	0x0420, 0x0421, 0x0422, 0x0423, 0x0424, 0x0425, 0x0426, 0x0427,
+	0x0428, 0x0429, 0x042a, 0x042b, 0x042c, 0x042d, 0x042e, 0x042f,
+	0x0400, 0x0401, 0x0402, 0x0403, 0x0404, 0x0405, 0x0406, 0x0407,
+	0x0408, 0x0409, 0x040a, 0x040b, 0x040c, 0x040d, 0x040e, 0x040f,
+	0x0460, 0x0460, 0x0462, 0x0462, 0x0464, 0x0464, 0x0466, 0x0466,
+	0x0468, 0x0468, 0x046a, 0x046a, 0x046c, 0x046c, 0x046e, 0x046e,
+	0x0470, 0x0470, 0x0472, 0x0472, 0x0474, 0x0474, 0x0476, 0x0476,
+	0x0478, 0x0478, 0x047a, 0x047a, 0x047c, 0x047c, 0x047e, 0x047e,
+	0x0480, 0x0480, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487,
+	0x0488, 0x0489, 0x048a, 0x048a, 0x048c, 0x048c, 0x048e, 0x048e,
+	0x0490, 0x0490, 0x0492, 0x0492, 0x0494, 0x0494, 0x0496, 0x0496,
+	0x0498, 0x0498, 0x049a, 0x049a, 0x049c, 0x049c, 0x049e, 0x049e,
+	0x04a0, 0x04a0, 0x04a2, 0x04a2, 0x04a4, 0x04a4, 0x04a6, 0x04a6,
+	0x04a8, 0x04a8, 0x04aa, 0x04aa, 0x04ac, 0x04ac, 0x04ae, 0x04ae,
+	0x04b0, 0x04b0, 0x04b2, 0x04b2, 0x04b4, 0x04b4, 0x04b6, 0x04b6,
+	0x04b8, 0x04b8, 0x04ba, 0x04ba, 0x04bc, 0x04bc, 0x04be, 0x04be,
+	0x04c0, 0x04c1, 0x04c1, 0x04c3, 0x04c3, 0x04c5, 0x04c5, 0x04c7,
+	0x04c7, 0x04c9, 0x04c9, 0x04cb, 0x04cb, 0x04cd, 0x04cd, 0x04c0,
+	0x04d0, 0x04d0, 0x04d2, 0x04d2, 0x04d4, 0x04d4, 0x04d6, 0x04d6,
+	0x04d8, 0x04d8, 0x04da, 0x04da, 0x04dc, 0x04dc, 0x04de, 0x04de,
+	0x04e0, 0x04e0, 0x04e2, 0x04e2, 0x04e4, 0x04e4, 0x04e6, 0x04e6,
+	0x04e8, 0x04e8, 0x04ea, 0x04ea, 0x04ec, 0x04ec, 0x04ee, 0x04ee,
+	0x04f0, 0x04f0, 0x04f2, 0x04f2, 0x04f4, 0x04f4, 0x04f6, 0x04f6,
+	0x04f8, 0x04f8, 0x04fa, 0x04fa, 0x04fc, 0x04fc, 0x04fe, 0x04fe,
+	0x0500, 0x0500, 0x0502, 0x0502, 0x0504, 0x0504, 0x0506, 0x0506,
+	0x0508, 0x0508, 0x050a, 0x050a, 0x050c, 0x050c, 0x050e, 0x050e,
+	0x0510, 0x0510, 0x0512, 0x0512, 0x0514, 0x0515, 0x0516, 0x0517,
+	0x0518, 0x0519, 0x051a, 0x051b, 0x051c, 0x051d, 0x051e, 0x051f,
+	0x0520, 0x0521, 0x0522, 0x0523, 0x0524, 0x0525, 0x0526, 0x0527,
+	0x0528, 0x0529, 0x052a, 0x052b, 0x052c, 0x052d, 0x052e, 0x052f,
+	0x0530, 0x0531, 0x0532, 0x0533, 0x0534, 0x0535, 0x0536, 0x0537,
+	0x0538, 0x0539, 0x053a, 0x053b, 0x053c, 0x053d, 0x053e, 0x053f,
+	0x0540, 0x0541, 0x0542, 0x0543, 0x0544, 0x0545, 0x0546, 0x0547,
+	0x0548, 0x0549, 0x054a, 0x054b, 0x054c, 0x054d, 0x054e, 0x054f,
+	0x0550, 0x0551, 0x0552, 0x0553, 0x0554, 0x0555, 0x0556, 0x0557,
+	0x0558, 0x0559, 0x055a, 0x055b, 0x055c, 0x055d, 0x055e, 0x055f,
+	0x0560, 0x0531, 0x0532, 0x0533, 0x0534, 0x0535, 0x0536, 0x0537,
+	0x0538, 0x0539, 0x053a, 0x053b, 0x053c, 0x053d, 0x053e, 0x053f,
+	0x0540, 0x0541, 0x0542, 0x0543, 0x0544, 0x0545, 0x0546, 0x0547,
+	0x0548, 0x0549, 0x054a, 0x054b, 0x054c, 0x054d, 0x054e, 0x054f,
+	0x0550, 0x0551, 0x0552, 0x0553, 0x0554, 0x0555, 0x0556, 0xffff,
+	0x17f6, 0x2c63, 0x1d7e, 0x1d7f, 0x1d80, 0x1d81, 0x1d82, 0x1d83,
+	0x1d84, 0x1d85, 0x1d86, 0x1d87, 0x1d88, 0x1d89, 0x1d8a, 0x1d8b,
+	0x1d8c, 0x1d8d, 0x1d8e, 0x1d8f, 0x1d90, 0x1d91, 0x1d92, 0x1d93,
+	0x1d94, 0x1d95, 0x1d96, 0x1d97, 0x1d98, 0x1d99, 0x1d9a, 0x1d9b,
+	0x1d9c, 0x1d9d, 0x1d9e, 0x1d9f, 0x1da0, 0x1da1, 0x1da2, 0x1da3,
+	0x1da4, 0x1da5, 0x1da6, 0x1da7, 0x1da8, 0x1da9, 0x1daa, 0x1dab,
+	0x1dac, 0x1dad, 0x1dae, 0x1daf, 0x1db0, 0x1db1, 0x1db2, 0x1db3,
+	0x1db4, 0x1db5, 0x1db6, 0x1db7, 0x1db8, 0x1db9, 0x1dba, 0x1dbb,
+	0x1dbc, 0x1dbd, 0x1dbe, 0x1dbf, 0x1dc0, 0x1dc1, 0x1dc2, 0x1dc3,
+	0x1dc4, 0x1dc5, 0x1dc6, 0x1dc7, 0x1dc8, 0x1dc9, 0x1dca, 0x1dcb,
+	0x1dcc, 0x1dcd, 0x1dce, 0x1dcf, 0x1dd0, 0x1dd1, 0x1dd2, 0x1dd3,
+	0x1dd4, 0x1dd5, 0x1dd6, 0x1dd7, 0x1dd8, 0x1dd9, 0x1dda, 0x1ddb,
+	0x1ddc, 0x1ddd, 0x1dde, 0x1ddf, 0x1de0, 0x1de1, 0x1de2, 0x1de3,
+	0x1de4, 0x1de5, 0x1de6, 0x1de7, 0x1de8, 0x1de9, 0x1dea, 0x1deb,
+	0x1dec, 0x1ded, 0x1dee, 0x1def, 0x1df0, 0x1df1, 0x1df2, 0x1df3,
+	0x1df4, 0x1df5, 0x1df6, 0x1df7, 0x1df8, 0x1df9, 0x1dfa, 0x1dfb,
+	0x1dfc, 0x1dfd, 0x1dfe, 0x1dff, 0x1e00, 0x1e00, 0x1e02, 0x1e02,
+	0x1e04, 0x1e04, 0x1e06, 0x1e06, 0x1e08, 0x1e08, 0x1e0a, 0x1e0a,
+	0x1e0c, 0x1e0c, 0x1e0e, 0x1e0e, 0x1e10, 0x1e10, 0x1e12, 0x1e12,
+	0x1e14, 0x1e14, 0x1e16, 0x1e16, 0x1e18, 0x1e18, 0x1e1a, 0x1e1a,
+	0x1e1c, 0x1e1c, 0x1e1e, 0x1e1e, 0x1e20, 0x1e20, 0x1e22, 0x1e22,
+	0x1e24, 0x1e24, 0x1e26, 0x1e26, 0x1e28, 0x1e28, 0x1e2a, 0x1e2a,
+	0x1e2c, 0x1e2c, 0x1e2e, 0x1e2e, 0x1e30, 0x1e30, 0x1e32, 0x1e32,
+	0x1e34, 0x1e34, 0x1e36, 0x1e36, 0x1e38, 0x1e38, 0x1e3a, 0x1e3a,
+	0x1e3c, 0x1e3c, 0x1e3e, 0x1e3e, 0x1e40, 0x1e40, 0x1e42, 0x1e42,
+	0x1e44, 0x1e44, 0x1e46, 0x1e46, 0x1e48, 0x1e48, 0x1e4a, 0x1e4a,
+	0x1e4c, 0x1e4c, 0x1e4e, 0x1e4e, 0x1e50, 0x1e50, 0x1e52, 0x1e52,
+	0x1e54, 0x1e54, 0x1e56, 0x1e56, 0x1e58, 0x1e58, 0x1e5a, 0x1e5a,
+	0x1e5c, 0x1e5c, 0x1e5e, 0x1e5e, 0x1e60, 0x1e60, 0x1e62, 0x1e62,
+	0x1e64, 0x1e64, 0x1e66, 0x1e66, 0x1e68, 0x1e68, 0x1e6a, 0x1e6a,
+	0x1e6c, 0x1e6c, 0x1e6e, 0x1e6e, 0x1e70, 0x1e70, 0x1e72, 0x1e72,
+	0x1e74, 0x1e74, 0x1e76, 0x1e76, 0x1e78, 0x1e78, 0x1e7a, 0x1e7a,
+	0x1e7c, 0x1e7c, 0x1e7e, 0x1e7e, 0x1e80, 0x1e80, 0x1e82, 0x1e82,
+	0x1e84, 0x1e84, 0x1e86, 0x1e86, 0x1e88, 0x1e88, 0x1e8a, 0x1e8a,
+	0x1e8c, 0x1e8c, 0x1e8e, 0x1e8e, 0x1e90, 0x1e90, 0x1e92, 0x1e92,
+	0x1e94, 0x1e94, 0x1e96, 0x1e97, 0x1e98, 0x1e99, 0x1e9a, 0x1e9b,
+	0x1e9c, 0x1e9d, 0x1e9e, 0x1e9f, 0x1ea0, 0x1ea0, 0x1ea2, 0x1ea2,
+	0x1ea4, 0x1ea4, 0x1ea6, 0x1ea6, 0x1ea8, 0x1ea8, 0x1eaa, 0x1eaa,
+	0x1eac, 0x1eac, 0x1eae, 0x1eae, 0x1eb0, 0x1eb0, 0x1eb2, 0x1eb2,
+	0x1eb4, 0x1eb4, 0x1eb6, 0x1eb6, 0x1eb8, 0x1eb8, 0x1eba, 0x1eba,
+	0x1ebc, 0x1ebc, 0x1ebe, 0x1ebe, 0x1ec0, 0x1ec0, 0x1ec2, 0x1ec2,
+	0x1ec4, 0x1ec4, 0x1ec6, 0x1ec6, 0x1ec8, 0x1ec8, 0x1eca, 0x1eca,
+	0x1ecc, 0x1ecc, 0x1ece, 0x1ece, 0x1ed0, 0x1ed0, 0x1ed2, 0x1ed2,
+	0x1ed4, 0x1ed4, 0x1ed6, 0x1ed6, 0x1ed8, 0x1ed8, 0x1eda, 0x1eda,
+	0x1edc, 0x1edc, 0x1ede, 0x1ede, 0x1ee0, 0x1ee0, 0x1ee2, 0x1ee2,
+	0x1ee4, 0x1ee4, 0x1ee6, 0x1ee6, 0x1ee8, 0x1ee8, 0x1eea, 0x1eea,
+	0x1eec, 0x1eec, 0x1eee, 0x1eee, 0x1ef0, 0x1ef0, 0x1ef2, 0x1ef2,
+	0x1ef4, 0x1ef4, 0x1ef6, 0x1ef6, 0x1ef8, 0x1ef8, 0x1efa, 0x1efb,
+	0x1efc, 0x1efd, 0x1efe, 0x1eff, 0x1f08, 0x1f09, 0x1f0a, 0x1f0b,
+	0x1f0c, 0x1f0d, 0x1f0e, 0x1f0f, 0x1f08, 0x1f09, 0x1f0a, 0x1f0b,
+	0x1f0c, 0x1f0d, 0x1f0e, 0x1f0f, 0x1f18, 0x1f19, 0x1f1a, 0x1f1b,
+	0x1f1c, 0x1f1d, 0x1f16, 0x1f17, 0x1f18, 0x1f19, 0x1f1a, 0x1f1b,
+	0x1f1c, 0x1f1d, 0x1f1e, 0x1f1f, 0x1f28, 0x1f29, 0x1f2a, 0x1f2b,
+	0x1f2c, 0x1f2d, 0x1f2e, 0x1f2f, 0x1f28, 0x1f29, 0x1f2a, 0x1f2b,
+	0x1f2c, 0x1f2d, 0x1f2e, 0x1f2f, 0x1f38, 0x1f39, 0x1f3a, 0x1f3b,
+	0x1f3c, 0x1f3d, 0x1f3e, 0x1f3f, 0x1f38, 0x1f39, 0x1f3a, 0x1f3b,
+	0x1f3c, 0x1f3d, 0x1f3e, 0x1f3f, 0x1f48, 0x1f49, 0x1f4a, 0x1f4b,
+	0x1f4c, 0x1f4d, 0x1f46, 0x1f47, 0x1f48, 0x1f49, 0x1f4a, 0x1f4b,
+	0x1f4c, 0x1f4d, 0x1f4e, 0x1f4f, 0x1f50, 0x1f59, 0x1f52, 0x1f5b,
+	0x1f54, 0x1f5d, 0x1f56, 0x1f5f, 0x1f58, 0x1f59, 0x1f5a, 0x1f5b,
+	0x1f5c, 0x1f5d, 0x1f5e, 0x1f5f, 0x1f68, 0x1f69, 0x1f6a, 0x1f6b,
+	0x1f6c, 0x1f6d, 0x1f6e, 0x1f6f, 0x1f68, 0x1f69, 0x1f6a, 0x1f6b,
+	0x1f6c, 0x1f6d, 0x1f6e, 0x1f6f, 0x1fba, 0x1fbb, 0x1fc8, 0x1fc9,
+	0x1fca, 0x1fcb, 0x1fda, 0x1fdb, 0x1ff8, 0x1ff9, 0x1fea, 0x1feb,
+	0x1ffa, 0x1ffb, 0x1f7e, 0x1f7f, 0x1f88, 0x1f89, 0x1f8a, 0x1f8b,
+	0x1f8c, 0x1f8d, 0x1f8e, 0x1f8f, 0x1f88, 0x1f89, 0x1f8a, 0x1f8b,
+	0x1f8c, 0x1f8d, 0x1f8e, 0x1f8f, 0x1f98, 0x1f99, 0x1f9a, 0x1f9b,
+	0x1f9c, 0x1f9d, 0x1f9e, 0x1f9f, 0x1f98, 0x1f99, 0x1f9a, 0x1f9b,
+	0x1f9c, 0x1f9d, 0x1f9e, 0x1f9f, 0x1fa8, 0x1fa9, 0x1faa, 0x1fab,
+	0x1fac, 0x1fad, 0x1fae, 0x1faf, 0x1fa8, 0x1fa9, 0x1faa, 0x1fab,
+	0x1fac, 0x1fad, 0x1fae, 0x1faf, 0x1fb8, 0x1fb9, 0x1fb2, 0x1fbc,
+	0x1fb4, 0x1fb5, 0x1fb6, 0x1fb7, 0x1fb8, 0x1fb9, 0x1fba, 0x1fbb,
+	0x1fbc, 0x1fbd, 0x1fbe, 0x1fbf, 0x1fc0, 0x1fc1, 0x1fc2, 0x1fc3,
+	0x1fc4, 0x1fc5, 0x1fc6, 0x1fc7, 0x1fc8, 0x1fc9, 0x1fca, 0x1fcb,
+	0x1fc3, 0x1fcd, 0x1fce, 0x1fcf, 0x1fd8, 0x1fd9, 0x1fd2, 0x1fd3,
+	0x1fd4, 0x1fd5, 0x1fd6, 0x1fd7, 0x1fd8, 0x1fd9, 0x1fda, 0x1fdb,
+	0x1fdc, 0x1fdd, 0x1fde, 0x1fdf, 0x1fe8, 0x1fe9, 0x1fe2, 0x1fe3,
+	0x1fe4, 0x1fec, 0x1fe6, 0x1fe7, 0x1fe8, 0x1fe9, 0x1fea, 0x1feb,
+	0x1fec, 0x1fed, 0x1fee, 0x1fef, 0x1ff0, 0x1ff1, 0x1ff2, 0x1ff3,
+	0x1ff4, 0x1ff5, 0x1ff6, 0x1ff7, 0x1ff8, 0x1ff9, 0x1ffa, 0x1ffb,
+	0x1ff3, 0x1ffd, 0x1ffe, 0x1fff, 0x2000, 0x2001, 0x2002, 0x2003,
+	0x2004, 0x2005, 0x2006, 0x2007, 0x2008, 0x2009, 0x200a, 0x200b,
+	0x200c, 0x200d, 0x200e, 0x200f, 0x2010, 0x2011, 0x2012, 0x2013,
+	0x2014, 0x2015, 0x2016, 0x2017, 0x2018, 0x2019, 0x201a, 0x201b,
+	0x201c, 0x201d, 0x201e, 0x201f, 0x2020, 0x2021, 0x2022, 0x2023,
+	0x2024, 0x2025, 0x2026, 0x2027, 0x2028, 0x2029, 0x202a, 0x202b,
+	0x202c, 0x202d, 0x202e, 0x202f, 0x2030, 0x2031, 0x2032, 0x2033,
+	0x2034, 0x2035, 0x2036, 0x2037, 0x2038, 0x2039, 0x203a, 0x203b,
+	0x203c, 0x203d, 0x203e, 0x203f, 0x2040, 0x2041, 0x2042, 0x2043,
+	0x2044, 0x2045, 0x2046, 0x2047, 0x2048, 0x2049, 0x204a, 0x204b,
+	0x204c, 0x204d, 0x204e, 0x204f, 0x2050, 0x2051, 0x2052, 0x2053,
+	0x2054, 0x2055, 0x2056, 0x2057, 0x2058, 0x2059, 0x205a, 0x205b,
+	0x205c, 0x205d, 0x205e, 0x205f, 0x2060, 0x2061, 0x2062, 0x2063,
+	0x2064, 0x2065, 0x2066, 0x2067, 0x2068, 0x2069, 0x206a, 0x206b,
+	0x206c, 0x206d, 0x206e, 0x206f, 0x2070, 0x2071, 0x2072, 0x2073,
+	0x2074, 0x2075, 0x2076, 0x2077, 0x2078, 0x2079, 0x207a, 0x207b,
+	0x207c, 0x207d, 0x207e, 0x207f, 0x2080, 0x2081, 0x2082, 0x2083,
+	0x2084, 0x2085, 0x2086, 0x2087, 0x2088, 0x2089, 0x208a, 0x208b,
+	0x208c, 0x208d, 0x208e, 0x208f, 0x2090, 0x2091, 0x2092, 0x2093,
+	0x2094, 0x2095, 0x2096, 0x2097, 0x2098, 0x2099, 0x209a, 0x209b,
+	0x209c, 0x209d, 0x209e, 0x209f, 0x20a0, 0x20a1, 0x20a2, 0x20a3,
+	0x20a4, 0x20a5, 0x20a6, 0x20a7, 0x20a8, 0x20a9, 0x20aa, 0x20ab,
+	0x20ac, 0x20ad, 0x20ae, 0x20af, 0x20b0, 0x20b1, 0x20b2, 0x20b3,
+	0x20b4, 0x20b5, 0x20b6, 0x20b7, 0x20b8, 0x20b9, 0x20ba, 0x20bb,
+	0x20bc, 0x20bd, 0x20be, 0x20bf, 0x20c0, 0x20c1, 0x20c2, 0x20c3,
+	0x20c4, 0x20c5, 0x20c6, 0x20c7, 0x20c8, 0x20c9, 0x20ca, 0x20cb,
+	0x20cc, 0x20cd, 0x20ce, 0x20cf, 0x20d0, 0x20d1, 0x20d2, 0x20d3,
+	0x20d4, 0x20d5, 0x20d6, 0x20d7, 0x20d8, 0x20d9, 0x20da, 0x20db,
+	0x20dc, 0x20dd, 0x20de, 0x20df, 0x20e0, 0x20e1, 0x20e2, 0x20e3,
+	0x20e4, 0x20e5, 0x20e6, 0x20e7, 0x20e8, 0x20e9, 0x20ea, 0x20eb,
+	0x20ec, 0x20ed, 0x20ee, 0x20ef, 0x20f0, 0x20f1, 0x20f2, 0x20f3,
+	0x20f4, 0x20f5, 0x20f6, 0x20f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb,
+	0x20fc, 0x20fd, 0x20fe, 0x20ff, 0x2100, 0x2101, 0x2102, 0x2103,
+	0x2104, 0x2105, 0x2106, 0x2107, 0x2108, 0x2109, 0x210a, 0x210b,
+	0x210c, 0x210d, 0x210e, 0x210f, 0x2110, 0x2111, 0x2112, 0x2113,
+	0x2114, 0x2115, 0x2116, 0x2117, 0x2118, 0x2119, 0x211a, 0x211b,
+	0x211c, 0x211d, 0x211e, 0x211f, 0x2120, 0x2121, 0x2122, 0x2123,
+	0x2124, 0x2125, 0x2126, 0x2127, 0x2128, 0x2129, 0x212a, 0x212b,
+	0x212c, 0x212d, 0x212e, 0x212f, 0x2130, 0x2131, 0x2132, 0x2133,
+	0x2134, 0x2135, 0x2136, 0x2137, 0x2138, 0x2139, 0x213a, 0x213b,
+	0x213c, 0x213d, 0x213e, 0x213f, 0x2140, 0x2141, 0x2142, 0x2143,
+	0x2144, 0x2145, 0x2146, 0x2147, 0x2148, 0x2149, 0x214a, 0x214b,
+	0x214c, 0x214d, 0x2132, 0x214f, 0x2150, 0x2151, 0x2152, 0x2153,
+	0x2154, 0x2155, 0x2156, 0x2157, 0x2158, 0x2159, 0x215a, 0x215b,
+	0x215c, 0x215d, 0x215e, 0x215f, 0x2160, 0x2161, 0x2162, 0x2163,
+	0x2164, 0x2165, 0x2166, 0x2167, 0x2168, 0x2169, 0x216a, 0x216b,
+	0x216c, 0x216d, 0x216e, 0x216f, 0x2160, 0x2161, 0x2162, 0x2163,
+	0x2164, 0x2165, 0x2166, 0x2167, 0x2168, 0x2169, 0x216a, 0x216b,
+	0x216c, 0x216d, 0x216e, 0x216f, 0x2180, 0x2181, 0x2182, 0x2183,
+	0x2183, 0xffff, 0x034b, 0x24b6, 0x24b7, 0x24b8, 0x24b9, 0x24ba,
+	0x24bb, 0x24bc, 0x24bd, 0x24be, 0x24bf, 0x24c0, 0x24c1, 0x24c2,
+	0x24c3, 0x24c4, 0x24c5, 0x24c6, 0x24c7, 0x24c8, 0x24c9, 0x24ca,
+	0x24cb, 0x24cc, 0x24cd, 0x24ce, 0x24cf, 0xffff, 0x0746, 0x2c00,
+	0x2c01, 0x2c02, 0x2c03, 0x2c04, 0x2c05, 0x2c06, 0x2c07, 0x2c08,
+	0x2c09, 0x2c0a, 0x2c0b, 0x2c0c, 0x2c0d, 0x2c0e, 0x2c0f, 0x2c10,
+	0x2c11, 0x2c12, 0x2c13, 0x2c14, 0x2c15, 0x2c16, 0x2c17, 0x2c18,
+	0x2c19, 0x2c1a, 0x2c1b, 0x2c1c, 0x2c1d, 0x2c1e, 0x2c1f, 0x2c20,
+	0x2c21, 0x2c22, 0x2c23, 0x2c24, 0x2c25, 0x2c26, 0x2c27, 0x2c28,
+	0x2c29, 0x2c2a, 0x2c2b, 0x2c2c, 0x2c2d, 0x2c2e, 0x2c5f, 0x2c60,
+	0x2c60, 0x2c62, 0x2c63, 0x2c64, 0x2c65, 0x2c66, 0x2c67, 0x2c67,
+	0x2c69, 0x2c69, 0x2c6b, 0x2c6b, 0x2c6d, 0x2c6e, 0x2c6f, 0x2c70,
+	0x2c71, 0x2c72, 0x2c73, 0x2c74, 0x2c75, 0x2c75, 0x2c77, 0x2c78,
+	0x2c79, 0x2c7a, 0x2c7b, 0x2c7c, 0x2c7d, 0x2c7e, 0x2c7f, 0x2c80,
+	0x2c80, 0x2c82, 0x2c82, 0x2c84, 0x2c84, 0x2c86, 0x2c86, 0x2c88,
+	0x2c88, 0x2c8a, 0x2c8a, 0x2c8c, 0x2c8c, 0x2c8e, 0x2c8e, 0x2c90,
+	0x2c90, 0x2c92, 0x2c92, 0x2c94, 0x2c94, 0x2c96, 0x2c96, 0x2c98,
+	0x2c98, 0x2c9a, 0x2c9a, 0x2c9c, 0x2c9c, 0x2c9e, 0x2c9e, 0x2ca0,
+	0x2ca0, 0x2ca2, 0x2ca2, 0x2ca4, 0x2ca4, 0x2ca6, 0x2ca6, 0x2ca8,
+	0x2ca8, 0x2caa, 0x2caa, 0x2cac, 0x2cac, 0x2cae, 0x2cae, 0x2cb0,
+	0x2cb0, 0x2cb2, 0x2cb2, 0x2cb4, 0x2cb4, 0x2cb6, 0x2cb6, 0x2cb8,
+	0x2cb8, 0x2cba, 0x2cba, 0x2cbc, 0x2cbc, 0x2cbe, 0x2cbe, 0x2cc0,
+	0x2cc0, 0x2cc2, 0x2cc2, 0x2cc4, 0x2cc4, 0x2cc6, 0x2cc6, 0x2cc8,
+	0x2cc8, 0x2cca, 0x2cca, 0x2ccc, 0x2ccc, 0x2cce, 0x2cce, 0x2cd0,
+	0x2cd0, 0x2cd2, 0x2cd2, 0x2cd4, 0x2cd4, 0x2cd6, 0x2cd6, 0x2cd8,
+	0x2cd8, 0x2cda, 0x2cda, 0x2cdc, 0x2cdc, 0x2cde, 0x2cde, 0x2ce0,
+	0x2ce0, 0x2ce2, 0x2ce2, 0x2ce4, 0x2ce5, 0x2ce6, 0x2ce7, 0x2ce8,
+	0x2ce9, 0x2cea, 0x2ceb, 0x2cec, 0x2ced, 0x2cee, 0x2cef, 0x2cf0,
+	0x2cf1, 0x2cf2, 0x2cf3, 0x2cf4, 0x2cf5, 0x2cf6, 0x2cf7, 0x2cf8,
+	0x2cf9, 0x2cfa, 0x2cfb, 0x2cfc, 0x2cfd, 0x2cfe, 0x2cff, 0x10a0,
+	0x10a1, 0x10a2, 0x10a3, 0x10a4, 0x10a5, 0x10a6, 0x10a7, 0x10a8,
+	0x10a9, 0x10aa, 0x10ab, 0x10ac, 0x10ad, 0x10ae, 0x10af, 0x10b0,
+	0x10b1, 0x10b2, 0x10b3, 0x10b4, 0x10b5, 0x10b6, 0x10b7, 0x10b8,
+	0x10b9, 0x10ba, 0x10bb, 0x10bc, 0x10bd, 0x10be, 0x10bf, 0x10c0,
+	0x10c1, 0x10c2, 0x10c3, 0x10c4, 0x10c5, 0xffff, 0xd21b, 0xff21,
+	0xff22, 0xff23, 0xff24, 0xff25, 0xff26, 0xff27, 0xff28, 0xff29,
+	0xff2a, 0xff2b, 0xff2c, 0xff2d, 0xff2e, 0xff2f, 0xff30, 0xff31,
+	0xff32, 0xff33, 0xff34, 0xff35, 0xff36, 0xff37, 0xff38, 0xff39,
+	0xff3a, 0xff5b, 0xff5c, 0xff5d, 0xff5e, 0xff5f, 0xff60, 0xff61,
+	0xff62, 0xff63, 0xff64, 0xff65, 0xff66, 0xff67, 0xff68, 0xff69,
+	0xff6a, 0xff6b, 0xff6c, 0xff6d, 0xff6e, 0xff6f, 0xff70, 0xff71,
+	0xff72, 0xff73, 0xff74, 0xff75, 0xff76, 0xff77, 0xff78, 0xff79,
+	0xff7a, 0xff7b, 0xff7c, 0xff7d, 0xff7e, 0xff7f, 0xff80, 0xff81,
+	0xff82, 0xff83, 0xff84, 0xff85, 0xff86, 0xff87, 0xff88, 0xff89,
+	0xff8a, 0xff8b, 0xff8c, 0xff8d, 0xff8e, 0xff8f, 0xff90, 0xff91,
+	0xff92, 0xff93, 0xff94, 0xff95, 0xff96, 0xff97, 0xff98, 0xff99,
+	0xff9a, 0xff9b, 0xff9c, 0xff9d, 0xff9e, 0xff9f, 0xffa0, 0xffa1,
+	0xffa2, 0xffa3, 0xffa4, 0xffa5, 0xffa6, 0xffa7, 0xffa8, 0xffa9,
+	0xffaa, 0xffab, 0xffac, 0xffad, 0xffae, 0xffaf, 0xffb0, 0xffb1,
+	0xffb2, 0xffb3, 0xffb4, 0xffb5, 0xffb6, 0xffb7, 0xffb8, 0xffb9,
+	0xffba, 0xffbb, 0xffbc, 0xffbd, 0xffbe, 0xffbf, 0xffc0, 0xffc1,
+	0xffc2, 0xffc3, 0xffc4, 0xffc5, 0xffc6, 0xffc7, 0xffc8, 0xffc9,
+	0xffca, 0xffcb, 0xffcc, 0xffcd, 0xffce, 0xffcf, 0xffd0, 0xffd1,
+	0xffd2, 0xffd3, 0xffd4, 0xffd5, 0xffd6, 0xffd7, 0xffd8, 0xffd9,
+	0xffda, 0xffdb, 0xffdc, 0xffdd, 0xffde, 0xffdf, 0xffe0, 0xffe1,
+	0xffe2, 0xffe3, 0xffe4, 0xffe5, 0xffe6, 0xffe7, 0xffe8, 0xffe9,
+	0xffea, 0xffeb, 0xffec, 0xffed, 0xffee, 0xffef, 0xfff0, 0xfff1,
+	0xfff2, 0xfff3, 0xfff4, 0xfff5, 0xfff6, 0xfff7, 0xfff8, 0xfff9,
+	0xfffa, 0xfffb, 0xfffc, 0xfffd, 0xfffe, 0xffff,
+};
+
+/*
+ * Allow full-width illegal characters :
+ * "MS windows 7" supports full-width-invalid-name-characters.
+ * So we should check half-width-invalid-name-characters(ASCII) only
+ * for compatibility.
+ *
+ * " * / : < > ? \ |
+ */
+static unsigned short bad_uni_chars[] = {
+	0x0022,         0x002A, 0x002F, 0x003A,
+	0x003C, 0x003E, 0x003F, 0x005C, 0x007C,
+	0
+};
+
+static int exfat_convert_char_to_ucs2(struct nls_table *nls,
+		const unsigned char *ch, int ch_len, unsigned short *ucs2,
+		int *lossy)
+{
+	int len;
+
+	*ucs2 = 0x0;
+
+	if (ch[0] < 0x80) {
+		*ucs2 = ch[0];
+		return 1;
+	}
+
+	len = nls->char2uni(ch, ch_len, ucs2);
+	if (len < 0) {
+		/* conversion failed */
+		if (lossy != NULL)
+			*lossy |= NLS_NAME_LOSSY;
+		*ucs2 = '_';
+		return 1;
+	}
+	return len;
+}
+
+static int exfat_convert_ucs2_to_char(struct nls_table *nls,
+		unsigned short ucs2, unsigned char *ch, int *lossy)
+{
+	int len;
+
+	ch[0] = 0x0;
+
+	if (ucs2 < 0x0080) {
+		ch[0] = ucs2;
+		return 1;
+	}
+
+	len = nls->uni2char(ucs2, ch, MAX_CHARSET_SIZE);
+	if (len < 0) {
+		/* conversion failed */
+		if (lossy != NULL)
+			*lossy |= NLS_NAME_LOSSY;
+		ch[0] = '_';
+		return 1;
+	}
+	return len;
+}
+
+unsigned short exfat_toupper(struct super_block *sb, unsigned short a)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	return sbi->vol_utbl[a] ? sbi->vol_utbl[a] : a;
+}
+
+static unsigned short *exfat_wstrchr(unsigned short *str, unsigned short wchar)
+{
+	while (*str) {
+		if (*(str++) == wchar)
+			return str;
+	}
+	return NULL;
+}
+
+int exfat_uniname_ncmp(struct super_block *sb, unsigned short *a,
+		unsigned short *b, unsigned int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++, a++, b++)
+		if (exfat_toupper(sb, *a) != exfat_toupper(sb, *b))
+			return 1;
+	return 0;
+}
+
+static int exfat_utf16_to_utf8(struct super_block *sb,
+		struct exfat_uni_name *p_uniname, unsigned char *p_cstring,
+		int buflen)
+{
+	int len;
+	const unsigned short *uniname = p_uniname->name;
+
+	/* always len >= 0 */
+	len = utf16s_to_utf8s(uniname, MAX_NAME_LENGTH, UTF16_HOST_ENDIAN,
+		p_cstring, buflen);
+	p_cstring[len] = '\0';
+	return len;
+}
+
+static int exfat_utf8_to_utf16(struct super_block *sb,
+		const unsigned char *p_cstring, const int len,
+		struct exfat_uni_name *p_uniname, int *p_lossy)
+{
+	int i, unilen, lossy = NLS_NAME_NO_LOSSY;
+	unsigned short upname[MAX_NAME_LENGTH + 1];
+	unsigned short *uniname = p_uniname->name;
+
+	WARN_ON(!len);
+
+	unilen = utf8s_to_utf16s(p_cstring, len, UTF16_HOST_ENDIAN,
+			(wchar_t *)uniname, MAX_NAME_LENGTH + 2);
+	if (unilen < 0) {
+		exfat_msg(sb, KERN_ERR,
+			"failed to %s (err : %d) nls len : %d",
+			__func__, unilen, len);
+		return unilen;
+	}
+
+	if (unilen > MAX_NAME_LENGTH) {
+		exfat_msg(sb, KERN_ERR,
+			"failed to %s (estr:ENAMETOOLONG) nls len : %d, unilen : %d > %d",
+			__func__, len, unilen, MAX_NAME_LENGTH);
+		return -ENAMETOOLONG;
+	}
+
+	p_uniname->name_len = unilen & 0xFF;
+
+	for (i = 0; i < unilen; i++) {
+		if (*uniname < 0x0020 ||
+		    exfat_wstrchr(bad_uni_chars, *uniname))
+			lossy |= NLS_NAME_LOSSY;
+
+		upname[i] = exfat_toupper(sb, *uniname);
+		uniname++;
+	}
+
+	*uniname = '\0';
+	p_uniname->name_len = unilen;
+	p_uniname->name_hash = exfat_calc_chksum_2byte(upname, unilen << 1, 0,
+			CS_DEFAULT);
+
+	if (p_lossy)
+		*p_lossy = lossy;
+	return unilen;
+}
+
+#define PLANE_SIZE	0x00010000
+#define SURROGATE_MASK	0xfffff800
+#define SURROGATE_PAIR	0x0000d800
+#define SURROGATE_LOW	0x00000400
+#define SURROGATE_BITS	0x000003ff
+
+unsigned short exfat_high_surrogate(unicode_t u)
+{
+	return ((u - PLANE_SIZE) >> 10) + SURROGATE_PAIR;
+}
+
+unsigned short exfat_low_surrogate(unicode_t u)
+{
+	return ((u - PLANE_SIZE) & SURROGATE_BITS) | SURROGATE_PAIR |
+		SURROGATE_LOW;
+}
+
+static int __exfat_utf16_to_nls(struct super_block *sb,
+		struct exfat_uni_name *p_uniname, unsigned char *p_cstring,
+		int buflen)
+{
+	int i, j, len, out_len = 0;
+	unsigned char buf[MAX_CHARSET_SIZE];
+	const unsigned short *uniname = p_uniname->name;
+	struct nls_table *nls = EXFAT_SB(sb)->nls_io;
+
+	i = 0;
+	while (i < MAX_NAME_LENGTH && out_len < (buflen - 1)) {
+		if (*uniname == '\0')
+			break;
+		if ((*uniname & SURROGATE_MASK) != SURROGATE_PAIR) {
+			len = exfat_convert_ucs2_to_char(nls, *uniname, buf,
+				NULL);
+		} else {
+			/* Process UTF-16 surrogate pair as one character */
+			if (!(*uniname & SURROGATE_LOW) &&
+			    i+1 < MAX_NAME_LENGTH &&
+			    (*(uniname+1) & SURROGATE_MASK) == SURROGATE_PAIR &&
+			    (*(uniname+1) & SURROGATE_LOW)) {
+				uniname++;
+				i++;
+			}
+
+			/*
+			 * UTF-16 surrogate pair encodes code points above
+			 * U+FFFF. Code points above U+FFFF are not supported
+			 * by kernel NLS framework therefore use replacement
+			 * character
+			 */
+			len = 1;
+			buf[0] = '_';
+		}
+
+		if (out_len + len >= buflen)
+			len = buflen - 1 - out_len;
+		out_len += len;
+
+		if (len > 1) {
+			for (j = 0; j < len; j++)
+				*p_cstring++ = buf[j];
+		} else { /* len == 1 */
+			*p_cstring++ = *buf;
+		}
+
+		uniname++;
+		i++;
+	}
+
+	*p_cstring = '\0';
+	return out_len;
+}
+
+static int exfat_nls_to_ucs2(struct super_block *sb,
+		const unsigned char *p_cstring, const int len,
+		struct exfat_uni_name *p_uniname, int *p_lossy)
+{
+	int i = 0, unilen = 0, lossy = NLS_NAME_NO_LOSSY;
+	unsigned short upname[MAX_NAME_LENGTH + 1];
+	unsigned short *uniname = p_uniname->name;
+	struct nls_table *nls = EXFAT_SB(sb)->nls_io;
+
+	WARN_ON(!len);
+
+	while (unilen < MAX_NAME_LENGTH && i < len) {
+		i += exfat_convert_char_to_ucs2(nls, p_cstring + i, len - i,
+				uniname, &lossy);
+
+		if (*uniname < 0x0020 ||
+		    exfat_wstrchr(bad_uni_chars, *uniname))
+			lossy |= NLS_NAME_LOSSY;
+
+		upname[unilen] = exfat_toupper(sb, *uniname);
+		uniname++;
+		unilen++;
+	}
+
+	if (p_cstring[i] != '\0')
+		lossy |= NLS_NAME_OVERLEN;
+
+	*uniname = '\0';
+	p_uniname->name_len = unilen;
+	p_uniname->name_hash = exfat_calc_chksum_2byte(upname, unilen << 1, 0,
+			CS_DEFAULT);
+
+	if (p_lossy)
+		*p_lossy = lossy;
+	return unilen;
+}
+
+int exfat_utf16_to_nls(struct super_block *sb, struct exfat_uni_name *uniname,
+		unsigned char *p_cstring, int buflen)
+{
+	if (EXFAT_SB(sb)->options.utf8)
+		return exfat_utf16_to_utf8(sb, uniname, p_cstring,
+				buflen);
+	return __exfat_utf16_to_nls(sb, uniname, p_cstring, buflen);
+}
+
+int exfat_nls_to_utf16(struct super_block *sb, const unsigned char *p_cstring,
+		const int len, struct exfat_uni_name *uniname, int *p_lossy)
+{
+	if (EXFAT_SB(sb)->options.utf8)
+		return exfat_utf8_to_utf16(sb, p_cstring, len,
+				uniname, p_lossy);
+	return exfat_nls_to_ucs2(sb, p_cstring, len, uniname, p_lossy);
+}
+
+static int exfat_load_upcase_table(struct super_block *sb,
+		sector_t sector, unsigned long long num_sectors,
+		unsigned int utbl_checksum)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	unsigned int sect_size = sb->s_blocksize;
+	unsigned int i, index = 0, checksum = 0;
+	int ret;
+	unsigned char skip = false;
+	unsigned short *upcase_table;
+
+	upcase_table = kcalloc(UTBL_COUNT, sizeof(unsigned short), GFP_KERNEL);
+	if (!upcase_table)
+		return -ENOMEM;
+
+	sbi->vol_utbl = upcase_table;
+	num_sectors += sector;
+
+	while (sector < num_sectors) {
+		struct buffer_head *bh;
+
+		bh = sb_bread(sb, sector);
+		if (!bh) {
+			exfat_msg(sb, KERN_ERR,
+				"failed to read sector(0x%llx)\n",
+				(unsigned long long)sector);
+			ret = -EIO;
+			goto free_table;
+		}
+		sector++;
+		for (i = 0; i < sect_size && index <= 0xFFFF; i += 2) {
+			unsigned short uni = get_unaligned_le16(bh->b_data + i);
+
+			checksum = ((checksum & 1) ? 0x80000000 : 0) +
+				(checksum >> 1) +
+				*(((unsigned char *)bh->b_data) + i);
+			checksum = ((checksum & 1) ? 0x80000000 : 0) +
+				(checksum >> 1) +
+				*(((unsigned char *)bh->b_data) + (i + 1));
+
+			if (skip) {
+				index += uni;
+				skip = false;
+			} else if (uni == index) {
+				index++;
+			} else if (uni == 0xFFFF) {
+				skip = true;
+			} else { /* uni != index , uni != 0xFFFF */
+				upcase_table[index] = uni;
+				index++;
+			}
+		}
+		brelse(bh);
+	}
+
+	if (index >= 0xFFFF && utbl_checksum == checksum)
+		return 0;
+
+	exfat_msg(sb, KERN_ERR,
+			"failed to load upcase table (idx : 0x%08x, chksum : 0x%08x, utbl_chksum : 0x%08x)\n",
+			index, checksum, utbl_checksum);
+	ret = -EINVAL;
+free_table:
+	exfat_free_upcase_table(sbi);
+	return ret;
+}
+
+static int exfat_load_default_upcase_table(struct super_block *sb)
+{
+	int i, ret = -EIO;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	unsigned char skip = false;
+	unsigned short uni = 0, *upcase_table;
+	unsigned int index = 0;
+
+	upcase_table = kcalloc(UTBL_COUNT, sizeof(unsigned short), GFP_KERNEL);
+	if (!upcase_table)
+		return -ENOMEM;
+
+	sbi->vol_utbl = upcase_table;
+
+	for (i = 0; index <= 0xFFFF && i < EXFAT_NUM_UPCASE; i++) {
+		uni = uni_def_upcase[i];
+		if (skip) {
+			index += uni;
+			skip = false;
+		} else if (uni == index) {
+			index++;
+		} else if (uni == 0xFFFF) {
+			skip = true;
+		} else {
+			upcase_table[index] = uni;
+			index++;
+		}
+	}
+
+	if (index >= 0xFFFF)
+		return 0;
+
+	/* FATAL error: default upcase table has error */
+	exfat_free_upcase_table(sbi);
+	return ret;
+}
+
+int exfat_create_upcase_table(struct super_block *sb)
+{
+	int i, ret;
+	unsigned int tbl_clu, type;
+	sector_t sector;
+	unsigned long long tbl_size, num_sectors;
+	unsigned char blksize_bits = sb->s_blocksize_bits;
+	struct exfat_chain clu;
+	struct exfat_dentry *ep;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct buffer_head *bh;
+
+	clu.dir = sbi->root_dir;
+	clu.flags = ALLOC_FAT_CHAIN;
+
+	while (clu.dir != EXFAT_EOF_CLUSTER) {
+		for (i = 0; i < sbi->dentries_per_clu; i++) {
+			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
+			if (!ep)
+				return -EIO;
+
+			type = exfat_get_entry_type(ep);
+			if (type == TYPE_UNUSED) {
+				brelse(bh);
+				break;
+			}
+
+			if (type != TYPE_UPCASE) {
+				brelse(bh);
+				continue;
+			}
+
+			tbl_clu  = le32_to_cpu(ep->dentry.upcase.start_clu);
+			tbl_size = le64_to_cpu(ep->dentry.upcase.size);
+
+			sector = exfat_cluster_to_sector(sbi, tbl_clu);
+			num_sectors = ((tbl_size - 1) >> blksize_bits) + 1;
+			ret = exfat_load_upcase_table(sb, sector, num_sectors,
+				le32_to_cpu(ep->dentry.upcase.checksum));
+
+			brelse(bh);
+			if (ret && ret != -EIO)
+				goto load_default;
+
+			/* load successfully */
+			return ret;
+		}
+
+		if (exfat_get_next_cluster(sb, &(clu.dir)))
+			return -EIO;
+	}
+
+load_default:
+	/* load default upcase table */
+	return exfat_load_default_upcase_table(sb);
+}
+
+void exfat_free_upcase_table(struct exfat_sb_info *sbi)
+{
+	kfree(sbi->vol_utbl);
+}

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);
+	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 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),
+	{}
+};
+
+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.");