From: Konrad Rzeszutek <konrad@virtualiron.com>
To: device-mapper development <dm-devel@redhat.com>, tj@kernel.org
Cc: Kay Sievers <kay.sievers@vrfy.org>,
jeff@garzik.org, linux-scsi@vger.kernel.org,
Mauelshagen@redhat.com, linux-kernel@vger.kernel.org,
linux-ide@vger.kernel.org, jens.axboe@oracle.com,
martin.petersen@oracle.com
Subject: Re: [dm-devel] Re: [PATCH 1/3] block: add alt_size
Date: Mon, 11 May 2009 09:45:34 -0400 [thread overview]
Message-ID: <20090511134534.GA32678@mars.virtualiron.com> (raw)
In-Reply-To: <4A058D5C.6030206@kernel.org>
.. snip ..
> > Also, values with magic block counts, while there is no way to get the
> > blocksize with the same interface, are pretty weird. I think the
> > current "size" attribute is just a bug.
>
> Logical block size is fixed at 512 bytes. Offset and size are always
> represented in multiples of 512 bytes and only get converted to
> hardware block size in the lld.
That interpretation is at odds with the work that Martin Peterson is
doing with the 4K support. In the e-mail titled: "Re: [PATCH 4 of 8] sd:
Physical block size and alignment support",
Message-ID:<yq1ab67b51p.fsf@sermon.lab.mkp.net> he says:
"
Konrad> about what a 'logical block', and 'physical block' is
Konrad> vs. 'hardware sector' ?
Well, another item on my todo list is to kill the notion of hardware
sector completely. The protocols have been referring to logical blocks
for ages.
It hasn't been a big problem until now because logical block size has
been equal to the hardware sector size. That's no longer a valid
assumption.
"
Are the ATA/SCSI/etc specs at odds with each other about this?
next prev parent reply other threads:[~2009-05-11 13:48 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-09 0:13 [GIT PATCH] block,scsi,libata: implement alt_size, take#2 Tejun Heo
2009-05-09 0:13 ` [PATCH 1/3] block: add alt_size Tejun Heo
2009-05-09 13:45 ` Kay Sievers
2009-05-09 14:04 ` Tejun Heo
2009-05-09 16:26 ` Kay Sievers
2009-05-11 13:45 ` Konrad Rzeszutek [this message]
2009-05-12 0:53 ` Tejun Heo
2009-05-09 0:13 ` [PATCH 2/3] scsi: add scsi_device->alt_capacity Tejun Heo
2009-05-09 4:23 ` James Bottomley
2009-05-09 16:09 ` Tejun Heo
2009-05-09 16:23 ` James Bottomley
2009-05-10 1:26 ` Tejun Heo
2009-05-15 19:44 ` ATA ULD (was Re: [PATCH 2/3] scsi: add scsi_device->alt_capacity) Jeff Garzik
2009-05-09 0:13 ` [PATCH 3/3] libata: export HPA size as alt_size Tejun Heo
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