LinuxLists.cc - Re: 2.6.29 regression: ATA bus errors on resume

2009-03-30 14:30:52

Subject: Re: 2.6.29 regression: ATA bus errors on resume

On 03/30/2009 11:00 AM, Tejun Heo wrote:
> Hello,
>
> For some reason, I can't find the original thread, so replying here.
>
> Niel Lambrechts wrote:
>>>>>> The ext4 errors are interleaved with hardware errors, and the ext4
>>>>>> errors are about I/O errors.
>>>>>>
>>>>>> EXT4-fs error (device sda6): __ext4_get_inode_loc: unable to read inode block - inode=2346519
>>>>>> EXT4-fs error (device sda6) in ext4_reserve_inode_write: IO failure
>>>>>>
>>>>>> This looks more like a hibernation problem than an ext4 problem.
>>>>>> Looks like the hard drive is being left in some inconsistent state
>>>>>> after resuming from hibernation.
>
> Yeap, ext4 is just the victim here.
>
>>>>> ata1.00: irq_stat 0x00400008, PHY RDY changed
>>>>> ata1: SError: { PHYRdyChg CommWake }
>>>> Your SATA hardware flags a connect-or-disconnect event ("PHY RDY"),
>>>> which requires us to abort a bunch of queued commands:
>>>>
>>>>> ata1.00: cmd 60/18:00:77:88:6f/00:00:0e:00:00/40 tag 0 ncq 12288 in
>>>>> res 50/00:30:07:b3:10/00:00:0c:00:00/40 Emask 0x10 (ATA bus error)
>>>> [...]
> ...
>>>> The SCSI subsystem aborts each of the queued commands.
>>> No .. this is the SCSI subsystem receives an ABORTED COMMAND return in
>>> sense data for each of the outstanding I/Os
>>>
>>> The only place these are generated is in ata_sense_to_error() which only
>>> occurs if there's some type of ata error.
>>>
>>> If I had to theorise, I'd say the system suspended with commands
>>> outstanding to the device. On resume, the device gets reset and returns
>>> some type of ATA error which gets translated to ABORTED COMMAND which
>>> causes a failure.
>>>
>>> In the mid layer, we translate ABORTED_COMMAND into a retry until the
>>> command runs out of them ... could it be there's a race readying the
>>> device and we run through the retries before it can accept the command?
>
> When libata-eh thinks that the problem isn't worth retrying, it sets
> scmd->retries to scmd->allowed so that it gets aborted immediately.
> The code is in ata_eh_qc_complete().
>
> Whether a command is to be retried or not is determined with
> ATA_QCFLAG_RETRY which is set in ata_eh_link_autopsy() for each failed
> command. Immediate-failure criteria is pretty strict - only driver
> software errors (AC_ERR_INVALID) and PC or other special commands
> which failed which got aborted by the device get the immediate pink
> slip. In this case, the commands are from FS and failed with
> AC_ERR_ATA_BUS, so it definitely doesn't fit into the criteria.
> Strange.
>
> How reproducible is the problem? Are you interested in trying out
> some debug patches?

Hi Tejun,

I think I should be able to reproduce when actively using X with 2.6.29,
and I have an external disk where I could backup to / boot from if the
corruption became a problem.

These issues are keeping me from 2.6.29 so I'll gladly help where I can,
if you can please provide me the patches and the .config settings that
may be required?

Niel

2009-03-30 14:40:27

by Jeff Garzik

[permalink] [raw]

Subject: Re: 2.6.29 regression: ATA bus errors on resume

Niel Lambrechts wrote:
> On 03/30/2009 11:00 AM, Tejun Heo wrote:
>> Hello,
>>
>> For some reason, I can't find the original thread, so replying here.
>>
>> Niel Lambrechts wrote:
>>>>>>> The ext4 errors are interleaved with hardware errors, and the ext4
>>>>>>> errors are about I/O errors.
>>>>>>>
>>>>>>> EXT4-fs error (device sda6): __ext4_get_inode_loc: unable to read inode block - inode=2346519
>>>>>>> EXT4-fs error (device sda6) in ext4_reserve_inode_write: IO failure
>>>>>>>
>>>>>>> This looks more like a hibernation problem than an ext4 problem.
>>>>>>> Looks like the hard drive is being left in some inconsistent state
>>>>>>> after resuming from hibernation.
>> Yeap, ext4 is just the victim here.
>>
>>>>>> ata1.00: irq_stat 0x00400008, PHY RDY changed
>>>>>> ata1: SError: { PHYRdyChg CommWake }
>>>>> Your SATA hardware flags a connect-or-disconnect event ("PHY RDY"),
>>>>> which requires us to abort a bunch of queued commands:
>>>>>
>>>>>> ata1.00: cmd 60/18:00:77:88:6f/00:00:0e:00:00/40 tag 0 ncq 12288 in
>>>>>> res 50/00:30:07:b3:10/00:00:0c:00:00/40 Emask 0x10 (ATA bus error)
>>>>> [...]
>> ...
>>>>> The SCSI subsystem aborts each of the queued commands.
>>>> No .. this is the SCSI subsystem receives an ABORTED COMMAND return in
>>>> sense data for each of the outstanding I/Os
>>>>
>>>> The only place these are generated is in ata_sense_to_error() which only
>>>> occurs if there's some type of ata error.
>>>>
>>>> If I had to theorise, I'd say the system suspended with commands
>>>> outstanding to the device. On resume, the device gets reset and returns
>>>> some type of ATA error which gets translated to ABORTED COMMAND which
>>>> causes a failure.
>>>>
>>>> In the mid layer, we translate ABORTED_COMMAND into a retry until the
>>>> command runs out of them ... could it be there's a race readying the
>>>> device and we run through the retries before it can accept the command?
>> When libata-eh thinks that the problem isn't worth retrying, it sets
>> scmd->retries to scmd->allowed so that it gets aborted immediately.
>> The code is in ata_eh_qc_complete().
>>
>> Whether a command is to be retried or not is determined with
>> ATA_QCFLAG_RETRY which is set in ata_eh_link_autopsy() for each failed
>> command. Immediate-failure criteria is pretty strict - only driver
>> software errors (AC_ERR_INVALID) and PC or other special commands
>> which failed which got aborted by the device get the immediate pink
>> slip. In this case, the commands are from FS and failed with
>> AC_ERR_ATA_BUS, so it definitely doesn't fit into the criteria.
>> Strange.
>>
>> How reproducible is the problem? Are you interested in trying out
>> some debug patches?
>
> Hi Tejun,
>
> I think I should be able to reproduce when actively using X with 2.6.29,
> and I have an external disk where I could backup to / boot from if the
> corruption became a problem.
>
> These issues are keeping me from 2.6.29 so I'll gladly help where I can,
> if you can please provide me the patches and the .config settings that
> may be required?
>
> Niel
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Any chance you could use bisect to narrow down the problem commit?

http://kernel.org/pub/software/scm/git/docs/v1.4.4.4/howto/isolate-bugs-with-bisect.txt

This should identify which patch caused your problems, if you have a
known good starting point (such as 2.6.28).

Jeff

2009-04-01 19:48:31

by Niel Lambrechts

Hello,

Niel Lambrechts wrote:
> On 04/06/2009 09:39 PM, Tejun Heo wrote:
> Sorry, my bad - I assumed the 2nd patch actually made a functional
> difference... :)
>
> Here is the output on 2.6.29.1 with your new patch - still nothing
> serious happening, resume still seems okay!

Hmm... none of the debugging messages got triggered, so there should
be no noticeable timing change. It seems like you're being lucky for
the time being. Can you please keep testing and report back?

Thanks.

--
tejun