Re: [Bugme-new] [Bug 11792] New: Oops when reading /proc/megaraid/hba0/diskdrives-ch*

[Boaz Harrosh <bharrosh@panasas.com>]

FUJITA Tomonori wrote:
> On Wed, 22 Oct 2008 11:04:44 +0200
> Boaz Harrosh <bharrosh@panasas.com> wrote:
> 
>> FUJITA Tomonori wrote:
>>> On Tue, 21 Oct 2008 22:22:37 +0200
>>> "Pascal Terjan" <pterjan@gmail.com> wrote:
>>>
>>>> On Tue, Oct 21, 2008 at 9:54 PM, Matthew Wilcox <matthew@wil.cx> wrote:
>>>>> On Tue, Oct 21, 2008 at 12:47:01PM -0700, Andrew Morton wrote:
>>>>>>> Latest working kernel version: 2.6.24
>>>>>>> Earliest failing kernel version: 2.6.27-rc8
>>>>>> It's a regression.
>>>>>>
>>>>>>> Pid: 2319, comm: diff Not tainted (2.6.27-server-0.rc8.2mnb #1)
>>>>> It's also a distro kernel by the looks of things.  Can it be reproduced
>>>>> with an upstream kernel?
>>>> I will try booting the server on vanilla kernel but I'm not sure when
>>>> (we already rebooted it 2 times recently and users won't enjoy it).
>>>>
>>>> This is a distro kernel but I don't see patches that could impact this :
>>>> http://svn.mandriva.com/cgi-bin/viewvc.cgi/packages/cooker/kernel/current/PATCHES/patches/
>>>>
>>>> Machine is a old HP NetServer LT 6000
>>>>
>>>> 04:03.1 I2O: Intel Corporation 80960RP (i960RP) Microprocessor (rev
>>>> 09) (prog-if 01)
>>>> 	Subsystem: Hewlett-Packard Company MegaRAID, Integrated NetRAID
>>>> 	Flags: bus master, fast Back2Back, medium devsel, latency 64, IRQ 11
>>>> 	Memory at f4000000 (32-bit, prefetchable) [size=64M]
>>>> 	[virtual] Expansion ROM at a8130000 [disabled] [size=32K]
>>>> 	Capabilities: [80] Power Management version 2
>>>> 	Kernel driver in use: megaraid_legacy
>>>> 	Kernel modules: i2o_core, megaraid
>>> This patch helps?
>>>
>>>
>>> diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c
>>> index 28c9da7..9294ed8 100644
>>> --- a/drivers/scsi/megaraid.c
>>> +++ b/drivers/scsi/megaraid.c
>>> @@ -4414,12 +4414,14 @@ mega_internal_command(adapter_t *adapter, megacmd_t *mc, mega_passthru *pthru)
>>>  
>>>  	scmd = &adapter->int_scmd;
>>>  	memset(scmd, 0, sizeof(Scsi_Cmnd));
>>> +	memset(adapter->int_cdb, 0, sizeof(adapter->int_cdb));
>>>  
>>>  	sdev = kzalloc(sizeof(struct scsi_device), GFP_KERNEL);
>>>  	scmd->device = sdev;
>>>  
>>>  	scmd->device->host = adapter->host;
>>>  	scmd->host_scribble = (void *)scb;
>>> +	scmd->cmnd = adapter->int_cdb;
>>>  	scmd->cmnd[0] = MEGA_INTERNAL_CMD;
>>>  
>>>  	scb->state |= SCB_ACTIVE;
>>> diff --git a/drivers/scsi/megaraid.h b/drivers/scsi/megaraid.h
>>> index ee70bd4..5ffec15 100644
>>> --- a/drivers/scsi/megaraid.h
>>> +++ b/drivers/scsi/megaraid.h
>>> @@ -889,6 +889,7 @@ typedef struct {
>>>  	u8	sglen;	/* f/w supported scatter-gather list length */
>>>  
>>>  	scb_t			int_scb;
>>> +	unsigned char		int_cdb[MAX_COMMAND_SIZE];
>>>  	Scsi_Cmnd		int_scmd;
>>>  	struct mutex		int_mtx;	/* To synchronize the internal
>>>  						commands */
>>>
>>> --
>> Hi TOMO.
>>
>> This might not be enough for example I don't see the allocation of sense_buffer.
>> It might be much easer to allocate using the new command allocation API James
>> did, just for such cases. These are: scsi_allocate_command/scsi_free_command
> 
> Yeah, it might be. It's fine by me too. But this code path is used
> only for issuing internal special commands. It doesn't use the great
> portion of scsi_cmnd. For example, these commands don't use sense
> buffer, I think. The code path uses scsi_cmnd just for hooking scb_t,
> a structure that megaraid allocates per command.

OK Thanks.
I was not sure because it looks like in mega_cmd_done(), if the status is
0x2 (CHECK_CONDITION) then it would set the sense_buffer. But from what
you say, the HW will never return 0x2 in case of an Internal-Command. I
Just wanted to make sure.

Boaz