Re: [PATCH 1/8] exofs: Kbuild, Headers and osd utils

Boaz Harrosh
2009-02-16T10:29:12Z

FUJITA Tomonori wrote:
> On Mon, 16 Feb 2009 11:19:21 +0200
> Boaz Harrosh <bharrosh@panasas.com> wrote:
>
>>>> Also looking
>>>> ahead I will have RAID 0, 1, 5, and 6 on objects of different devices. bio
>>>> is the perfect collector for memory information in this situation.
>>> You will add such features to exofs, handling multiple devices
>>> internally?
>>>
>> Multiple objects on Multiple devices, Yes.
>
> I thought that exofs is kinda example (reference) file system.
>
> Nobody has seen your code. Let's discuss when we have the
> code. Over-designing for what we've not seen is not a good idea.
>

Thanks for the insults, and high credit ;)

Yes it's "kinda example (reference) file system" of a pNFS-objects
file system. What can I do life is tough.

>
>>>> exofs is not the first and only file system who is using bios. Proof of
>>>> the matter is that block exports a bio submit routine.
>>> Seems that exofs just passes pages and the ULD sends a SCSI command
>>> including these pages. I don't see how exofs needs to handle bio
>>> directly.
>>>
>> How do you propose to collect these pages? and keep them without allocating
>> an extra list? without pre-allocating a struct request? and without re-inventing
>> the bio structure?
>
> I don't think that allocating an extra list (or something) to keep
> them hurts performance. We can talk about it when you have the real
> performance results.

So you are the one that starts to invent the wheel here. I thought I was
the one that does that, only you only called me by names, because you never showed
me where.

But please only answer one question for me: Please don't write back if you do not
answer this question:

Why do other filesystems allow to use bios? are they going to stop? Who is going
to remove that?

And as I said, I am going to remove it for now, please be patient. You have never
herd from me that I refuse to do it, did you?

Boaz