lkml.org 
[lkml]   [2012]   [Jul]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/2] virtio-scsi: fix parsing of hotplug/hot-unplug LUN number
On 07/26/12 09:21, James Bottomley wrote:
> On Thu, 2012-07-26 at 11:04 +0200, Paolo Bonzini wrote:
>> Il 26/07/2012 10:52, James Bottomley ha scritto:
>>>>> +static unsigned int virtscsi_get_lun(u8 *lun_bytes)
>>>>> +{
>>>>> + unsigned int lun = (lun_bytes[2] << 8) | lun_bytes[3];
>>>>> + return lun & 16383;
>>>>> +}
>>>>> +
>>> Why are you rolling your own incomplete version of scsilun_to_int here?
>>
>> Because scsilun_to_int does not do the AND, so it would have exactly the
>> same bug I'm fixing.
>
> It's not a bug ... it's the encoding. All the other devices use this
> too. Ideally we should have switched to 64 bit lun numbers for the
> encoding to be exact, but nothing so far has gone over 32 bits. If we
> don't encode the Address method as part of the lun number, we don't get
> the reverse transform right and the addressing often fails.
>
> That does mean that arrays that use address method=1 in REPORT LUNS have
> their lun numbers start at 16384.

Has it already been considered to modify scsilun_to_int() such that LUN
numbers start at zero even for addressing method 1 ? This is what e.g.
the function scst_unpack_lun() already does. See also
http://scst.svn.sourceforge.net/viewvc/scst/trunk/scst/src/scst_lib.c?revision=HEAD&view=markup.

Bart.


\
 
 \ /
  Last update: 2012-07-26 13:02    [W:0.096 / U:10.900 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site