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From:   "Sungjong Seo" <sj1557.seo@samsung.com>
To:     "'Tetsuhiro Kohada'" <kohada.tetsuhiro@dc.mitsubishielectric.co.jp>
Cc:     <mori.takahiro@ab.mitsubishielectric.co.jp>,
        <motai.hirotaka@aj.mitsubishielectric.co.jp>,
        "'Namjae Jeon'" <namjae.jeon@samsung.com>,
        <linux-fsdevel@vger.kernel.org>, <linux-kernel@vger.kernel.org>
In-Reply-To: <20200520075641.32441-1-kohada.tetsuhiro@dc.mitsubishielectric.co.jp>
Subject: RE: [PATCH] exfat: optimize dir-cache
Date:   Mon, 1 Jun 2020 21:08:44 +0900
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References: <CGME20200520075735epcas1p269372d222e25f3fd51b7979f5b7cdc61@epcas1p2.samsung.com>
        <20200520075641.32441-1-kohada.tetsuhiro@dc.mitsubishielectric.co.jp>
Sender: linux-kernel-owner@vger.kernel.org
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> Optimize directory access based on exfat_entry_set_cache.
>  - Hold bh instead of copied d-entry.
>  - Modify bh->data directly instead of the copied d-entry.
>  - Write back the retained bh instead of rescanning the d-entry-set.
> And
>  - Remove unused cache related definitions.
> 
> Signed-off-by: Tetsuhiro Kohada
> <kohada.tetsuhiro@dc.mitsubishielectric.co.jp>

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

> ---
>  fs/exfat/dir.c      | 197 +++++++++++++++++---------------------------
>  fs/exfat/exfat_fs.h |  27 +++---
>  fs/exfat/file.c     |  15 ++--
>  fs/exfat/inode.c    |  53 +++++-------
>  fs/exfat/namei.c    |  14 ++--
>  5 files changed, 124 insertions(+), 182 deletions(-)
> 
> diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index
> b5a237c33d50..2902d285bf20 100644
> --- a/fs/exfat/dir.c
> +++ b/fs/exfat/dir.c
> @@ -32,35 +32,30 @@ 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);
> +	es = exfat_get_dentry_set(sb, p_dir, entry, ES_ALL_ENTRIES);
>  	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++) {
> +	for (i = 2; i < es->num_entries; i++) {
> +		struct exfat_dentry *ep = exfat_get_dentry_cached(es, i);
> +
>  		/* end of name entry */
>  		if (exfat_get_entry_type(ep) != TYPE_EXTEND)
> -			goto free_es;
> +			break;
> 
>  		exfat_extract_uni_name(ep, uniname);
>  		uniname += EXFAT_FILE_NAME_LEN;
>  	}
> 
> -free_es:
> -	kfree(es);
> +	exfat_free_dentry_set(es, false);
>  }
> 
>  /* read a directory entry from the opened directory */ @@ -590,62 +585,33
> @@ int exfat_remove_entries(struct inode *inode, struct exfat_chain
*p_dir,
>  	return 0;
>  }
> 
> -int exfat_update_dir_chksum_with_entry_set(struct super_block *sb,
> -		struct exfat_entry_set_cache *es, int sync)
> +void exfat_update_dir_chksum_with_entry_set(struct
> +exfat_entry_set_cache *es)
>  {
> -	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;
> +	int chksum_type = CS_DIR_ENTRY, i;
>  	unsigned short chksum = 0;
> +	struct exfat_dentry *ep;
> 
> -	for (i = 0; i < num_entries; i++) {
> -		chksum = exfat_calc_chksum_2byte(&es->entries[i],
> DENTRY_SIZE,
> -			chksum, chksum_type);
> +	for (i = 0; i < es->num_entries; i++) {
> +		ep = exfat_get_dentry_cached(es, i);
> +		chksum = exfat_calc_chksum_2byte(ep, DENTRY_SIZE, chksum,
> +						 chksum_type);
>  		chksum_type = CS_DEFAULT;
>  	}
> +	ep = exfat_get_dentry_cached(es, 0);
> +	ep->dentry.file.checksum = cpu_to_le16(chksum);
> +	es->modified = true;
> +}
> 
> -	es->entries[0].dentry.file.checksum = cpu_to_le16(chksum);
> +void exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync)
> +{
> +	int i;
> 
> -	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);
> -		}
> +	for (i = 0; i < es->num_bh; i++) {
> +		if (es->modified)
> +			exfat_update_bh(es->sb, es->bh[i], sync);
> +		brelse(es->bh[i]);
>  	}
> -
> -	return 0;
> -err_out:
> -	return -EIO;
> +	kfree(es);
>  }
> 
>  static int exfat_walk_fat_chain(struct super_block *sb, @@ -820,34
> +786,40 @@ static bool exfat_validate_entry(unsigned int type,
>  	}
>  }
> 
> +struct exfat_dentry *exfat_get_dentry_cached(
> +	struct exfat_entry_set_cache *es, int num) {
> +	int off = es->start_off + num * DENTRY_SIZE;
> +	struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];
> +	char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb);
> +
> +	return (struct exfat_dentry *)p;
> +}
> +
>  /*
>   * 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.
> + * Note It provides a direct pointer to bh->data via
> exfat_get_dentry_cached().
> + * User should call exfat_get_dentry_set() after setting 'modified' 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)
> +		struct exfat_chain *p_dir, int entry, unsigned int type)
>  {
> -	int ret;
> +	int ret, i, num_bh;
>  	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;
> +	struct exfat_dentry *ep;
> +	int num_entries;
>  	enum exfat_validate_dentry_mode mode = ES_MODE_STARTED;
>  	struct buffer_head *bh;
> 
> @@ -861,11 +833,18 @@ struct exfat_entry_set_cache
> *exfat_get_dentry_set(struct super_block *sb,
>  	if (ret)
>  		return NULL;
> 
> +	es = kzalloc(sizeof(*es), GFP_KERNEL);
> +	if (!es)
> +		return NULL;
> +	es->sb = sb;
> +	es->modified = false;
> +
>  	/* byte offset in cluster */
>  	byte_offset = EXFAT_CLU_OFFSET(byte_offset, sbi);
> 
>  	/* byte offset in sector */
>  	off = EXFAT_BLK_OFFSET(byte_offset, sb);
> +	es->start_off = off;
> 
>  	/* sector offset in cluster */
>  	sec = EXFAT_B_TO_BLK(byte_offset, sb); @@ -873,72 +852,46 @@ struct
> exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
> 
>  	bh = sb_bread(sb, sec);
>  	if (!bh)
> -		return NULL;
> -
> -	ep = (struct exfat_dentry *)(bh->b_data + off);
> -	entry_type = exfat_get_entry_type(ep);
> +		goto free_es;
> +	es->bh[es->num_bh++] = bh;
> 
> -	if (entry_type != TYPE_FILE && entry_type != TYPE_DIR)
> -		goto release_bh;
> +	ep = exfat_get_dentry_cached(es, 0);
> +	if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
> +		goto free_es;
> 
>  	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)
> +	num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE,
> sb);
> +	for (i = 1; i < num_bh; i++) {
> +		/* get the next sector */
> +		if (exfat_is_last_sector_in_cluster(sbi, sec)) {
> +			if (p_dir->flags == ALLOC_NO_FAT_CHAIN)
> +				clu++;
> +			else if (exfat_get_next_cluster(sb, &clu))
>  				goto free_es;
> -			off = 0;
> -			ep = (struct exfat_dentry *)bh->b_data;
> +			sec = exfat_cluster_to_sector(sbi, clu);
>  		} else {
> -			ep++;
> -			off += DENTRY_SIZE;
> +			sec++;
>  		}
> -		pos++;
> +
> +		bh = sb_bread(sb, sec);
> +		if (!bh)
> +			goto free_es;
> +		es->bh[es->num_bh++] = bh;
>  	}
> 
> -	if (file_ep)
> -		*file_ep = &es->entries[0];
> -	brelse(bh);
> +	/* validiate cached dentries */
> +	for (i = 1; i < num_entries; i++) {
> +		ep = exfat_get_dentry_cached(es, i);
> +		if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
> +			goto free_es;
> +	}
>  	return es;
> 
>  free_es:
> -	kfree(es);
> -release_bh:
> -	brelse(bh);
> +	exfat_free_dentry_set(es, false);
>  	return NULL;
>  }
> 
> diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h index
> 294aa7792bc3..5caad1380818 100644
> --- a/fs/exfat/exfat_fs.h
> +++ b/fs/exfat/exfat_fs.h
> @@ -71,10 +71,8 @@ enum {
>  #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
> +/* Enough size to hold 256 dentry (even 512 Byte sector) */
> +#define DIR_CACHE_SIZE		(256*sizeof(struct
exfat_dentry)/512+1)
> 
>  #define EXFAT_HINT_NONE		-1
>  #define EXFAT_MIN_SUBDIR	2
> @@ -170,14 +168,12 @@ struct exfat_hint {  };
> 
>  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;
> +	struct super_block *sb;
> +	bool modified;
> +	unsigned int start_off;
> +	int num_bh;
> +	struct buffer_head *bh[DIR_CACHE_SIZE];
>  	unsigned int num_entries;
> -	struct exfat_dentry entries[];
>  };
> 
>  struct exfat_dir_entry {
> @@ -451,8 +447,7 @@ 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);
> +void exfat_update_dir_chksum_with_entry_set(struct
> +exfat_entry_set_cache *es);
>  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,
> @@ -463,9 +458,11 @@ int exfat_find_location(struct super_block *sb,
> struct exfat_chain *p_dir,  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_dentry *exfat_get_dentry_cached(
> +	struct exfat_entry_set_cache *es, int num);
>  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);
> +		struct exfat_chain *p_dir, int entry, unsigned int type);
> void
> +exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync);
>  int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain
> *p_dir);
> 
>  /* inode.c */
> diff --git a/fs/exfat/file.c b/fs/exfat/file.c index
> 84f3d31a3a55..8e3f0eef45d7 100644
> --- a/fs/exfat/file.c
> +++ b/fs/exfat/file.c
> @@ -96,11 +96,9 @@ 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 */ @@ -153,12 +151,15 @@
> int __exfat_truncate(struct inode *inode, loff_t new_size)
>  	/* update the directory entry */
>  	if (!evict) {
>  		struct timespec64 ts;
> +		struct exfat_dentry *ep, *ep2;
> +		struct exfat_entry_set_cache *es;
> 
>  		es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
> -				ES_ALL_ENTRIES, &ep);
> +				ES_ALL_ENTRIES);
>  		if (!es)
>  			return -EIO;
> -		ep2 = ep + 1;
> +		ep = exfat_get_dentry_cached(es, 0);
> +		ep2 = exfat_get_dentry_cached(es, 1);
> 
>  		ts = current_time(inode);
>  		exfat_set_entry_time(sbi, &ts,
> @@ -185,10 +186,8 @@ int __exfat_truncate(struct inode *inode, loff_t
> new_size)
>  			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);
> +		exfat_update_dir_chksum_with_entry_set(es);
> +		exfat_free_dentry_set(es, inode_needs_sync(inode));
>  	}
> 
>  	/* cut off from the FAT chain */
> diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c index
> 3f367d081cd6..ef7cf7a6d187 100644
> --- a/fs/exfat/inode.c
> +++ b/fs/exfat/inode.c
> @@ -19,7 +19,6 @@
> 
>  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; @@ -43,11 +42,11 @@ static
> int __exfat_write_inode(struct inode *inode, int sync)
>  	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);
> +	es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
> ES_ALL_ENTRIES);
>  	if (!es)
>  		return -EIO;
> -	ep2 = ep + 1;
> +	ep = exfat_get_dentry_cached(es, 0);
> +	ep2 = exfat_get_dentry_cached(es, 1);
> 
>  	ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode));
> 
> @@ -77,9 +76,9 @@ static int __exfat_write_inode(struct inode *inode, int
> sync)
>  	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;
> +	exfat_update_dir_chksum_with_entry_set(es);
> +	exfat_free_dentry_set(es, sync);
> +	return 0;
>  }
> 
>  int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
> @@ -110,8 +109,6 @@ static int exfat_map_cluster(struct inode *inode,
> unsigned int clu_offset,
>  	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); @@ -222,34 +219,28 @@
> static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
>  		num_clusters += num_to_be_allocated;
>  		*clu = new_clu.dir;
> 
> -		if (ei->dir.dir != DIR_DELETED) {
> +		if (ei->dir.dir != DIR_DELETED && modified) {
> +			struct exfat_dentry *ep;
> +			struct exfat_entry_set_cache *es;
> +
>  			es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
> -				ES_ALL_ENTRIES, &ep);
> +				ES_ALL_ENTRIES);
>  			if (!es)
>  				return -EIO;
>  			/* get stream entry */
> -			ep++;
> +			ep = exfat_get_dentry_cached(es, 1);
> 
>  			/* 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);
> +			ep->dentry.stream.flags = ei->flags;
> +			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;
> +
> +			exfat_update_dir_chksum_with_entry_set(es);
> +			exfat_free_dentry_set(es, inode_needs_sync(inode));
> 
>  		} /* end of if != DIR_DELETED */
> 
> diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c index
> 48f4df883f3b..5b0f35329d63 100644
> --- a/fs/exfat/namei.c
> +++ b/fs/exfat/namei.c
> @@ -600,8 +600,6 @@ static int exfat_find(struct inode *dir, struct qstr
> *qname,
>  	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); @@ -660,10 +658,14 @@
> static int exfat_find(struct inode *dir, struct qstr *qname,
> 
>  		info->num_subdirs = count;
>  	} else {
> -		es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES,
> &ep);
> +		struct exfat_dentry *ep, *ep2;
> +		struct exfat_entry_set_cache *es;
> +
> +		es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES);
>  		if (!es)
>  			return -EIO;
> -		ep2 = ep + 1;
> +		ep = exfat_get_dentry_cached(es, 0);
> +		ep2 = exfat_get_dentry_cached(es, 1);
> 
>  		info->type = exfat_get_entry_type(ep);
>  		info->attr = le16_to_cpu(ep->dentry.file.attr);
> @@ -681,7 +683,7 @@ static int exfat_find(struct inode *dir, struct qstr
> *qname,
>  			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);
> -			kfree(es);
> +			exfat_free_dentry_set(es, false);
>  			return -EIO;
>  		}
> 
> @@ -700,7 +702,7 @@ static int exfat_find(struct inode *dir, struct qstr
> *qname,
>  				ep->dentry.file.access_time,
>  				ep->dentry.file.access_date,
>  				0);
> -		kfree(es);
> +		exfat_free_dentry_set(es, false);
> 
>  		if (info->type == TYPE_DIR) {
>  			exfat_chain_set(&cdir, info->start_clu,
> --
> 2.25.0