From: "Namjae Jeon" <namjae.jeon@samsung.com>
To: <Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp>
Cc: <Mori.Takahiro@ab.MitsubishiElectric.co.jp>,
<Motai.Hirotaka@aj.MitsubishiElectric.co.jp>,
"'Sungjong Seo'" <sj1557.seo@samsung.com>,
<linux-fsdevel@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
"'Tetsuhiro Kohada''" <kohada.t2@gmail.com>
Subject: RE: [PATCH] exfat: retain 'VolumeFlags' properly
Date: Wed, 15 Jul 2020 10:54:48 +0900 [thread overview]
Message-ID: <015801d65a4a$ebedd380$c3c97a80$@samsung.com> (raw)
In-Reply-To: <TY2PR01MB2875C88DD10CC13D0C70DE1690610@TY2PR01MB2875.jpnprd01.prod.outlook.com>
> Thanks for your reply.
>
> > > Also, rename ERR_MEDIUM to MED_FAILURE.
> > I think that MEDIA_FAILURE looks better.
>
> I think so too.
> If so, should I change VOL_DIRTY to VOLUME_DIRTY?
Yes, maybe.
>
> > > -int exfat_set_vol_flags(struct super_block *sb, unsigned short
> > > new_flag)
> > > +int exfat_set_vol_flags(struct super_block *sb, unsigned short
> > > +new_flags)
> > > {
> > > struct exfat_sb_info *sbi = EXFAT_SB(sb);
> > > struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
> > > bool sync;
> > If dirty bit is set in on-disk volume flags, we can just return 0 at the beginning of this function ?
>
> That's right.
> Neither 'set VOL_DIRTY' nor 'set VOL_CLEAN' makes a change to volume flags.
>
>
> > > + if (new_flags == VOL_CLEAN)
> > > + new_flags = (sbi->vol_flags & ~VOL_DIRTY) | sbi->vol_flags_noclear;
> > > + else
> > > + new_flags |= sbi->vol_flags;
> > > +
> > > /* flags are not changed */
> > > - if (sbi->vol_flag == new_flag)
> > > + if (sbi->vol_flags == new_flags)
> > > return 0;
> > >
> > > - sbi->vol_flag = new_flag;
> > > + sbi->vol_flags = new_flags;
> > >
> > > /* skip updating volume dirty flag,
> > > * if this volume has been mounted with read-only @@ -114,9 +119,9
> > > @@ int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flag)
> > > if (sb_rdonly(sb))
> > > return 0;
> > >
> > > - p_boot->vol_flags = cpu_to_le16(new_flag);
> > > + p_boot->vol_flags = cpu_to_le16(new_flags);
> > How about set or clear only dirty bit to on-disk volume flags instead
> > of using
> > sbi->vol_flags_noclear ?
> > if (set)
> > p_boot->vol_flags |= cpu_to_le16(VOL_DIRTY);
> > else
> > p_boot->vol_flags &= cpu_to_le16(~VOL_DIRTY);
>
> In this way, the initial VOL_DIRTY cannot be retained.
> The purpose of this patch is to avoid losing the initial VOL_DIRTY and MED_FAILURE.
> Furthermore, I'm also thinking of setting MED_FAILURE.
I know what you do. I mean this function does not need to be called if volume dirty
Is already set on on-disk volume flags as I said earlier.
>
> However, the formula for 'new_flags' may be a bit complicated.
> Is it better to change to the following?
>
> if (new_flags == VOL_CLEAN)
> new_flags = sbi->vol_flags & ~VOL_DIRTY
> else
> new_flags |= sbi->vol_flags;
>
> new_flags |= sbi->vol_flags_noclear;
>
>
> one more point,
> Is there a better name than 'vol_flags_noclear'?
> (I can't come up with a good name anymore)
It looks complicated. It would be better to simply set/clear VOLUME DIRTY bit.
Thanks!
>
> BR
> ---
> Kohada Tetsuhiro <Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp>
next prev parent reply other threads:[~2020-07-15 1:54 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200708095813epcas1p2277cdf7de6a8bb20c27bcd030eec431f@epcas1p2.samsung.com>
2020-07-08 9:57 ` [PATCH] exfat: retain 'VolumeFlags' properly Tetsuhiro Kohada
2020-07-13 4:52 ` Namjae Jeon
2020-07-14 1:56 ` Kohada.Tetsuhiro
2020-07-15 1:54 ` Namjae Jeon [this message]
2020-07-15 10:06 ` Tetsuhiro Kohada
2020-07-30 6:24 ` Tetsuhiro Kohada
2020-07-30 6:59 ` Namjae Jeon
2020-07-31 1:29 ` Tetsuhiro Kohada
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