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 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

> James

Gabriel