Re: [pnfs] [PATCH 05/28] pnfsblock: expose scsi interface

[Boaz Harrosh <bharrosh@panasas.com>]

On Wed, Mar 12 2008 at 20:10 +0200, Fredric Isaman <iisaman@citi.umich.edu> wrote:
> 
> On Wed, 12 Mar 2008, Jason Glasgow wrote:
> 
>> Christoph,
>>
>> Putting device discovery in user space a valid alternative implementation,
>> and we will pursue that model.
>>
>> -Jason
>>
>>
>> On Wed, Mar 12, 2008 at 12:43 PM, Christoph Hellwig <hch@infradead.org>
>> wrote:
>>
>>> On Wed, Mar 12, 2008 at 06:33:34PM +0200, Benny Halevy wrote:
>>>> This calls for a layering violation.
>>>>
>>>> To fill-in more context, here's an excerpt from the next patch,
>>>> showing how you use shost_class to scan all scsi disks:
> 
> The referenced code is an adhoc hack that does what we need it to for now. 
> We would *love* to be able to just call in to some scsi function that fits 
> our needs
> 
>>> Yes, absolutely.  No one outside of few places in the core scsi code
>>> should ever iterate over the scsi disks.
>>>
> 
> Is this for locking reasons?
> 
>>>> My question is how should a proper API between the scsi layer and
>>>> the block layout driver look like?
>>>>
>>>> Can you list your requirements, e.g.:
>>>> - scanning all available devices,
>>>>
>>>> - discovering new devices on the fly
>>>>
>>>> - getting notified for new devices?
>>> Neither.  pnfs shouldn't open block devices from kernelspace at all,
>>> but do it's disovery in userspace.
>>>
> 
> 
> Basically, we are given a disk signature, (an array of offset, byte
> sequence pairs) and want to match it against some visible disk (ignoring
> partitions), or know that it is not currently visible.
> 
> Thus our requirement are:
> 
> Scan all available block devices (though all available SCSI devices is a
> workable substitute).
> 
> Notification of new devices would be a helpful in optimizing rescans for 
> unmapped disk signatures.
> 
> 
> As Jason mentions, we will pursue doing this in userspace.
> 
>  	Fred
> 
> 
OK I found:
#ifndef __i386__
#undef CONFIG_SCSI_OMIT_FLASHPOINT
#define CONFIG_SCSI_OMIT_FLASHPOINT
#endif

try patch below and report
---
BusLogic: Remove total bullshit

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
---
git-diff --stat -p
 drivers/scsi/BusLogic.h |    5 -----
 1 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/BusLogic.h b/drivers/scsi/BusLogic.h
index bfbfb5c..0f0d7f3 100644
--- a/drivers/scsi/BusLogic.h
+++ b/drivers/scsi/BusLogic.h
@@ -38,11 +38,6 @@
   CONFIG_PCI set.
 */
 
-#ifndef __i386__
-#undef CONFIG_SCSI_OMIT_FLASHPOINT
-#define CONFIG_SCSI_OMIT_FLASHPOINT
-#endif
-
 #ifndef CONFIG_PCI
 #undef CONFIG_SCSI_OMIT_FLASHPOINT
 #define CONFIG_SCSI_OMIT_FLASHPOINT