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From: Karel Zak <kzak@redhat.com>
To: Venkatraman S <venkat@linaro.org>
Cc: util-linux@vger.kernel.org
Subject: Re: libblkid: newbie question about enabling whole disk sysfs probe
Date: Mon, 22 Oct 2012 16:28:13 +0200	[thread overview]
Message-ID: <20121022142813.GD21724@x2.net.home> (raw)
In-Reply-To: <CAFSEfh2myyk98cZWRU149rUAm+1e7DiAKxsUU=jBxb5ZNoLABA@mail.gmail.com>

On Mon, Oct 22, 2012 at 06:15:57PM +0530, Venkatraman S wrote:
>        blkid_probe_enable_topology(pr, 1);

This is strings based interface (NAME=value). It's probably
better to use:

   tp = blkid_probe_get_topology(pr);

   blkid_topology_get_alignment_offset(tp);

see libblkid/samples/topology.c.


> I am able to get to the property value (which is set from the sysfs
> value for the disk).
> 
> But when mkswap is invokded with /dev/sdbX, then sysfs_probe is not
> able to discover the parent disk's sysfs property.

Really? It should be able to translate the partition name to the
whole-disk name and us it.

# ./sample-topology /dev/sdd1
----- binary interface:
	alignment offset     : 0
	minimum io size      : 4096
	optimal io size      : 262144
	logical sector size  : 4096
	physical sector size : 4096
----- NAME=value interface (values: 4):
	MINIMUM_IO_SIZE = 4096
	OPTIMAL_IO_SIZE = 262144
	PHYSICAL_SECTOR_SIZE = 4096
	LOGICAL_SECTOR_SIZE = 4096



> Any help would be great.

 What exactly is your goal?

    Karel


-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

  reply	other threads:[~2012-10-22 14:28 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-22 12:45 libblkid: newbie question about enabling whole disk sysfs probe Venkatraman S
2012-10-22 14:28 ` Karel Zak [this message]
2012-10-22 16:33   ` Venkatraman S

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