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

[Laurent Riffard <laurent.riffard@free.fr>]

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.

-- 
laurent