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Date: Mon, 3 Feb 2014 00:15:06 -0800
From: Christoph Hellwig <hch@infradead.org>
To: Mikulas Patocka <mpatocka@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>,
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Subject: Re: [PATCH] block devices: validate block device capacity
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On Fri, Jan 31, 2014 at 03:20:17AM -0500, Mikulas Patocka wrote:
> So if you think you can support 16TiB devices and leave pgoff_t 32-bit, 
> send a patch that does it.
> 
> Until you make it, you should apply the patch that I sent, that prevents 
> kernel lockups or data corruption when the user uses 16TiB device on 
> 32-bit kernel.

Exactly.  I had actually looked into support for > 16TiB devices for
a NAS use case a while ago, but when explaining the effort involves
the idea was dropped quickly.  The Linux block device is too deeply
tied to the pagecache to make it easily feasible.