On 08/08/2017 05:25 PM, Alan Stern wrote:
> On Tue, 8 Aug 2017, Hannes Reinecke wrote:
>
>> When checking the model and vendor string we need to use the
>> minimum value of either string, otherwise we'll miss out on
>> wildcard matches.
>> And we should avoid matching anything with zero size as this
>> match will be incorrect.
>> Without this patch certain Hitachi arrays will not be presenting
>> VPD pages correctly.
>>
>> Fixes: 5e7ff2c ("SCSI: fix new bug in scsi_dev_info_list string matching")
>> Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
>
> This is very questionable. As described in commit b704f70ce200 ("SCSI:
> fix bug in scsi_dev_info_list matching"), there are devices which have
> vendor or model strings of length 0, and there are entries in the
> global device list like that too. With this patch, such devices and
> such entries would never match anything.
>
> Also, the idea of using the minimum length of either string doesn't
> sound right. It would allow a device with string "abc" to match an
> entry in the list with string "abcd", which would be wrong.
>
> Suggestion:
>
> Allow a device string to match a list entry if the lengths
> are equal or the list entry is shorter (this would be a
> wildcard match), but not if the list entry is longer. Here
> the device string length is after leading and trailing blanks
> have been removed.
>
> As a corollary, allow an empty device string to match an empty
> list entry but nothing else.
>
> Alan Stern
>
Well, so far we haven't encountered any of those devices.
I _have_ validated the patch with the known problematic inquiry strings,
namely
"HITACHI" "OPEN-V"
"Inateck" " "
" " "Scanner"
"Promise" "STEX"
and it gives the correct result for all of these.
If you have any inquiry strings for which this does _not_ produce the
correct result please let me know.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
