Re: [PATCH] zfcp: Test kmalloc failure in scsi_get_vpd_page()

Boaz Harrosh
2009-11-08T09:19:43Z

On 11/05/2009 09:41 PM, James Bottomley wrote:
> On Thu, 2009-11-05 at 10:29 +0200, Boaz Harrosh wrote:
>> On 11/04/2009 07:50 PM, James Bottomley wrote:
>>> On Wed, 2009-11-04 at 18:18 +0200, Boaz Harrosh wrote:
>>>
>>> The point of checking is not to send a VPD inquiry to USB devices that
>>> don't support it. These have a very limited range of supported VPD
>>> pages.
>>>
>>
>> OK thanks. But maybe just define a MIN_INQUIRY_SIZE instead of hard
>> coded 32 everywhere, and use that. So in future if such a device is
>> found we can easily change it.
>
> So the minimum inquiry size would actually be 36 ... from
> scsi_scan.c ... and that's hard coded to a value too.
>

two wrongs don't make a right ;-) But yes, sorry, that's a wrong name.
I meant minimum-vpd-page-inquiry, a specifc constant for that function
we are talking about.

>> (Never say never ;-))
>
> I'm hoping that by the time USB devices get complex enough to need more
> than 28 VPD pages, they've actually discovered what conforming to the
> standards means.
>

I don't understand what your saying. I'm making a simple and sane point.
A new comer, from looking at the API, will say "Haa I only need 12 bytes
lets set that". But no the buffer has dual purpose, one get the page I want,
but zero check these crap USB devices. (And all those other subtle things)
So you are actually going to argue that a patch should introduce an
hard coded 32 unexplained, and refuse a constant that actually communicates
the issue, which also covers our asses from the hopes we make.
Because I sure hope so too, but I'm also 48 years old.

> James
>
>

Boaz