Re: 2.6.24-rc3-mm1: I/O error, system hangs

[Gabriel C <nix.or.die@googlemail.com>]

James Bottomley wrote:
> On Sat, 2007-11-24 at 18:54 +0100, Gabriel C wrote:
>> James Bottomley wrote:
>>> On Sat, 2007-11-24 at 13:57 +0100, Laurent Riffard wrote:
>>>> Le 24.11.2007 07:42, James Bottomley a écrit :
>>>>> On Fri, 2007-11-23 at 18:52 +0100, Laurent Riffard wrote:
>>>>>> Le 23.11.2007 12:38, Hannes Reinecke a écrit :
>>>>>>> Hannes Reinecke wrote:
>>>>>>>> Laurent Riffard wrote:
>>>>>>>>> Le 21.11.2007 23:41, Andrew Morton a écrit :
>>>>>>>>>> On Wed, 21 Nov 2007 22:45:22 +0100
>>>>>>>>>> Laurent Riffard <laurent.riffard@free.fr> wrote:
>>>>>>>>>>
>>>>>>>>>>> Le 21.11.2007 05:45, Andrew Morton a écrit :
>>>>>>>>>>>> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.24-rc3/2.6.24-rc3-mm1/
>>>>>>>>>>> Hello, 
>>>>>>>>>>>
>>>>>>>>>>> My system hangs shortly after I logged in Gnome desktop. SysRq-W shows
>>>>>>>>>>> that a bunch of task are blocked in "D" state, they seem to wait for
>>>>>>>>>>> some I/O completion. I can try to hand-copy some data if requested.
>>>>>>>>>>>
>>>>>>>>>>> I found these messages in dmesg:
>>>>>>>>>>>
>>>>>>>>>>> ~$ grep -C2 end_request dmesg-2.6.24-rc3-mm1 
>>>>>>>>>>> EXT3-fs: mounted filesystem with ordered data mode.
>>>>>>>>>>> sd 0:0:0:0: [sda] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK
>>>>>>>>>>> end_request: I/O error, dev sda, sector 16460
>>>>>>>>>>> ReiserFS: sda7: found reiserfs format "3.6" with standard journal
>>>>>>>>>>> ReiserFS: sda7: using ordered data mode
>>>>>>>>>>> --
>>>>>>>>>>> ReiserFS: sda7: Using r5 hash to sort names
>>>>>>>>>>> sd 0:0:1:0: [sdb] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK
>>>>>>>>>>> end_request: I/O error, dev sdb, sector 19632
>>>>>>>>>>> sd 0:0:1:0: [sdb] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK
>>>>>>>>>>> end_request: I/O error, dev sdb, sector 40037363
>>>>>>>>>>> Adding 1048568k swap on /dev/mapper/vglinux1-lvswap.  Priority:-1 extents:1 across:1048568k
>>>>>>>>>>> lp0: using parport0 (interrupt-driven).
>>>>>>>>>>>
>>>>>>>>>>> These errors occur *only* with 2.6.24-rc3-mm1, they are 100% reproducible.
>>>>>>>>>>> 2.6.24-rc3 and 2.6.24-rc2-mm1 are fine.
>>>>>>>>>>>
>>>>>>>>>>> Maybe something is broken in pata_via driver ?
>>>>>>>>>>>
>>>>>>>>>> Could be - libata-reimplement-ata_acpi_cbl_80wire-using-ata_acpi_gtm_xfermask.patch
>>>>>>>>>> and pata_amd-pata_via-de-couple-programming-of-pio-mwdma-and-udma-timings.patch
>>>>>>>>>> touch pata_via.c.
>>>>>>>>> None of the above...
>>>>>>>>>
>>>>>>>>> I did a bisection, it spotted git-scsi-misc.patch. 
>>>>>>>>> I just run 2.6.24-rc3-mm1 + revert-git-scsi-misc.patch, and it works fine.
>>>>>>>>>
>>>>>>>>> I guess commit 8655a546c83fc43f0a73416bbd126d02de7ad6c0 "[SCSI] Do not 
>>>>>>>>> requeue requests if REQ_FAILFAST is set" is the real culprit. The other 
>>>>>>>>> commits are touching documentation or drivers I don't use. I'll try 
>>>>>>>>> to revert only this one this evening.
>>>>>> I can confirm : reverting commit 8655a546c83fc43f0a73416bbd126d02de7ad6c0 
>>>>>> does fix the problem.
>>>>>>
>>>>>>>> Hmm. Weird. I'll have a look into it. Apparently I'll be returning an error where
>>>>>>>> I shouldn't. Checking ...
>>>>>>>>
>>>>>>> Ok, found it. We are blocking even special commands (ie requests with PREEMPT not set)
>>>>>>> when FAILFAST is set. Which is clearly wrong. The attached patch fixes this.
>>>>>> Sorry, it's not enough. 2.6.24-rc3-mm1 + your patch still hangs with I/O errors.
>>>>> I think the problem is the way we treat BLOCKED and QUIESCED (the latter
>>>>> is the state that the domain validation uses and which we cannot kill
>>>>> fastfail on).  It's definitely wrong to kill fastfail requests when the
>>>>> state is QUIESCE.
>>>>>
>>>>> This patch (which is applied on top of Hannes original) separates the
>>>>> BLOCK and QUIESCE states correctly ... does this fix the problem?
>>>> No, it doesn't help... (2.6.24-rc3-mm1 + your patch still has problems)
>>> OK, could you post dmesgs again, please.  I actually tested this with an
>>> aic79xx card, and for me it does cause Domain Validation to succeed
>>> again.
>>>
>> Are the patches indeed to fix that problem as well ? 
>>
>> http://lkml.org/lkml/2007/11/23/5
> 
> That dmesg is from an unknown SCSI card exhibiting Domain Validation
> problems, so it's a reasonable probability, yes ... but you'll need the
> additional hack I just did to prevent further intermittent failures.

My controller is:

03:0e.0 SCSI storage controller [0100]: Adaptec AIC-7892P U160/m [9005:008f] (rev 02)

I'll try the patches in a bit.

> 
> James
> 

Gabriel