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Subject: Re: Few problems in mtd system
From: Maxim Levitsky <maximlevitsky@gmail.com>
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Date: Thu, 07 Jan 2010 18:16:03 +0200
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On Thu, 2010-01-07 at 09:11 +0200, Artem Bityutskiy wrote: 
> On Sun, 2009-12-20 at 22:59 +0200, Maxim Levitsky wrote:
> > Folks, could you review my other questions about bugs in mtd core, and
> > tell your opinion?
> 
> The MTD subsystem is nor very inhabitant these days, so you are mostly
> on your own. I think you should just try fixing the issues you found,
> test them, be careful, and send patches.
> 
> I believe MTD subsystem have many issues with "hotpluggable" devices
> like your card, simply because no one probably worked seriously on this.
> Most MTD devices are on-board chips, so few people care about
> plugability.
> 
> > Yet another problem I found is inside add_mtd_blktrans_dev.
> > This function takes mtd_table_mutex but never releases it.
> > This sounds fishy, and deadlocks when it calls 'add_disk(gd);'
> > This function (I think in case partitions are detected on device)
> opens
> > block device, and this takes that lock too
> > (blktrans_open->get_mtd_device)> 
> 
> I vaguely remember there was a fix for this, may be in 2.6.33-rcX ?


I have recently posted a pathset that fixes everything, especially
hotplug.

Will be glad to hear feedback.


Best regards,
Maxim Levitsky