linux-kernel - Re: [PATCH 0/4] FS: userspace notification of errors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20090610210507.GF1381@ucw.cz>
Date:	Wed, 10 Jun 2009 23:05:07 +0200
From:	Pavel Machek <pavel@....cz>
To:	Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	"Karpov Denis.2 (EXT-Teleca/Helsinki)" <ext-denis.2.karpov@...ia.com>,
	"axboe@...nel.dk" <axboe@...nel.dk>,
	"hirofumi@...l.parknet.co.jp" <hirofumi@...l.parknet.co.jp>,
	"linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>,
	"linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"Hunter Adrian (Nokia-D/Helsinki)" <adrian.hunter@...ia.com>
Subject: Re: [PATCH 0/4] FS: userspace notification of errors

On Thu 2009-06-04 08:57:58, Artem Bityutskiy wrote:
> Andrew Morton wrote:
>> hm, I'm uncertain on the desirability or otherwise of the overall feature.
>>
>> Are there users or distros or device manufacturers asking for this?  
>> Where did the requirement come from?
>>
>> What downstream application will handle the uevent messages?  Do you
>> have some userspace design/plan in mind?
>>
>> IOW, it would be useful if we were told more about all of this, rather
>> than just staring at a kernel patch!
>
> As the original idea came from me, while whole implementation
> and design was done by Denis, I'll comment on this.
>
> Our use-case is about hand-held devices. We are particularly
> working with large FAT volumes on MMC. Do not question please
> why it is FAT and not something else :-) Anyway, FAT is very
> unreliable, and often hits errors, in which case it simply
> switches to read-only mode, and usually prints something to
> the printk ring buffer.

So fsck the mmc card on card insertion...? fsck.vfat on flash is
pretty fast operation (as it onl needs to read directories +
FATs). Android 1.5 implements this.

...otherwise you will loose data on two files sharing clusters, will
never recover lost clusters, etc.

Perhaps it would be feasible  to permit read-only mount of unclean
VFAT, run fsck in background, and buffer any changes in memory until
fsck finishes?

									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/