Re: [PATCH] Revert "block: WARN in __blk_put_request() for potential bio leak"

[Boaz Harrosh <bharrosh@panasas.com>]

On 06/10/2009 12:36 PM, FUJITA Tomonori wrote:
> On Wed, 10 Jun 2009 12:21:19 +0300
> Boaz Harrosh <bharrosh@panasas.com> wrote:
> 
>> On 06/10/2009 11:52 AM, FUJITA Tomonori wrote:
>>> On Wed, 10 Jun 2009 11:45:14 +0300
>>> Boaz Harrosh <bharrosh@panasas.com> wrote:
>>>
>>>> The fact that ALL block drivers call it for proper service of ALL ULDS,
>>>> does it not make it a rule?
>>> BSG SMP code is not ULD.
>>>
>> BSG is certainly a ULD, Upper-Layer-Driver that can issue block commands
>> through block layer and block-queue.
>>
>> SMP is a block device class that has it's own LLDs.
>>
>> The way I understand
>>
>> |---------|      |--------------|      |-----------|
>> | ULD     |----->|  block layer |----->| block LLD |
>> |---------|      |--------------|      |-----------|
>>
>> So I meant block ULD or block layer user code. That is what I meant
>> by ULD, what do you mean?
> 
> To me, ULD means SCSI upper layer driver, which is documented.
> 
> Where can I find a document about your definition of Block ULD, block
> LLD, etc?
> 
> 
> To me, looks like there is a different place for you.
> 

Sorry then, My bad. I though ULD/LLD is just Upper/Lower drivers of any
sub-system.
If it is only used for SCSI, then sorry I will not use it for any thing else.

> BTW, if you try to find a bio leak in the BSG SMP path, I guess that
> it's worth looking at the bounce path. There might be a leak.

once a request was put on the queue, or even before that, once some
memory was mapped. blk_end_request must be called by someone.
More and more code relays on that. Not doing so is just plain playing
with fire. Will you not agree?

Boaz