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From:   Namjae Jeon <linkinjeon@kernel.org>
Date:   Wed, 27 May 2020 20:29:52 +0900
Message-ID: <CAKYAXd_oG6dc7CNiHszKmhabHd2zrN_VOaNYaWRPES=7hRu+pA@mail.gmail.com>
Subject: Re: [PATCH] exfat: optimize dir-cache
To:     "Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp" 
        <Kohada.Tetsuhiro@dc.mitsubishielectric.co.jp>
Cc:     Sungjong Seo <sj1557.seo@samsung.com>,
        "Mori.Takahiro@ab.MitsubishiElectric.co.jp" 
        <Mori.Takahiro@ab.mitsubishielectric.co.jp>,
        "Motai.Hirotaka@aj.MitsubishiElectric.co.jp" 
        <Motai.Hirotaka@aj.mitsubishielectric.co.jp>,
        Namjae Jeon <namjae.jeon@samsung.com>,
        "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "kohada.t2@gmail.com" <kohada.t2@gmail.com>
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2020-05-27 17:00 GMT+09:00,
Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp
<Kohada.Tetsuhiro@dc.mitsubishielectric.co.jp>:
> Thank you for your comment.
>
>  >> +    for (i = 0; i < es->num_bh; i++) {
>  >> +            if (es->modified)
>  >> +                    exfat_update_bh(es->sb, es->bh[i], sync);
>  >
>  > Overall, it looks good to me.
>  > However, if "sync" is set, it looks better to return the result of
> exfat_update_bh().
>  > Of course, a tiny modification for exfat_update_bh() is also required.
>
>  I thought the same, while creating this patch.
>  However this patch has changed a lot and I didn't add any new error
> checking.
>  (So, the same behavior will occur even if an error occurs)
>
>  >> +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);
>  >
>  > In order to prevent illegal accesses to bh and dentries, it would be
> better to check validation for num and bh.
>
>  There is no new error checking for same reason as above.
>
>  I'll try to add error checking to this v2 patch.
>  Or is it better to add error checking in another patch?
The latter:)
Thanks!
>
> BR
> ---
> Kohada Tetsuhiro <Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp>