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From:   "Sungjong Seo" <sj1557.seo@samsung.com>
To:     "'Namjae Jeon'" <linkinjeon@kernel.org>
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Subject: RE: [PATCH v1 1/2] exfat: simplify empty entry hint
Date:   Mon, 31 Oct 2022 14:16:47 +0900
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Hello, Yuezhang Mo,

> This commit adds exfat_hint_empty_entry() to reduce code complexity and
> make code more readable.
>=20
> Signed-off-by: Yuezhang Mo <Yuezhang.Mo=40sony.com>
> Reviewed-by: Andy Wu <Andy.Wu=40sony.com>
> Reviewed-by: Aoyama Wataru <wataru.aoyama=40sony.com>
> ---
>  fs/exfat/dir.c =7C 56 ++++++++++++++++++++++++++++----------------------
>  1 file changed, 32 insertions(+), 24 deletions(-)
>=20
> diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c index
> 7b648b6662f0..a569f285f4fd 100644
> --- a/fs/exfat/dir.c
> +++ b/fs/exfat/dir.c
> =40=40 -934,6 +934,24 =40=40 struct exfat_entry_set_cache
> *exfat_get_dentry_set(struct super_block *sb,
>  	return NULL;
>  =7D
>=20
> +static inline void exfat_hint_empty_entry(struct exfat_inode_info *ei,
> +		struct exfat_hint_femp *candi_empty, struct exfat_chain *clu,
> +		int dentry, int num_entries)
> +=7B
> +	if (ei->hint_femp.eidx =3D=3D EXFAT_HINT_NONE =7C=7C
> +	    ei->hint_femp.count < num_entries =7C=7C

It seems like a good approach.
BTW, ei->hint_femp.count was already reset at the beginning of
exfat_find_dir_entry(). So condition-check above could be removed.
Is there any scenario I'm missing?

> +	    ei->hint_femp.eidx > dentry) =7B
> +		if (candi_empty->count =3D=3D 0) =7B
> +			candi_empty->cur =3D *clu;
> +			candi_empty->eidx =3D dentry;
> +		=7D
> +
> +		candi_empty->count++;
> +		if (candi_empty->count =3D=3D num_entries)
> +			ei->hint_femp =3D *candi_empty;
> +	=7D
> +=7D
> +
>  enum =7B
>  	DIRENT_STEP_FILE,
>  	DIRENT_STEP_STRM,
> =40=40 -958,7 +976,7 =40=40 int exfat_find_dir_entry(struct super_block *=
sb,
> struct exfat_inode_info *ei,  =7B
>  	int i, rewind =3D 0, dentry =3D 0, end_eidx =3D 0, num_ext =3D 0, len;
>  	int order, step, name_len =3D 0;
> -	int dentries_per_clu, num_empty =3D 0;
> +	int dentries_per_clu;
>  	unsigned int entry_type;
>  	unsigned short *uniname =3D NULL;
>  	struct exfat_chain clu;
> =40=40 -976,7 +994,15 =40=40 int exfat_find_dir_entry(struct super_block =
*sb,
> struct exfat_inode_info *ei,
>  		end_eidx =3D dentry;
>  	=7D
>=20
> -	candi_empty.eidx =3D EXFAT_HINT_NONE;
> +	if (ei->hint_femp.eidx =21=3D EXFAT_HINT_NONE &&
> +	    ei->hint_femp.count < num_entries)
> +		ei->hint_femp.eidx =3D EXFAT_HINT_NONE;
> +
> +	if (ei->hint_femp.eidx =3D=3D EXFAT_HINT_NONE)
> +		ei->hint_femp.count =3D 0;
> +
> +	candi_empty =3D ei->hint_femp;
> +

It would be nice to make the code block above a static inline function as w=
ell.

>  rewind:
>  	order =3D 0;
>  	step =3D DIRENT_STEP_FILE;
=5Bsnip=5D
> --
> 2.25.1