Re: sata_sil24 corruption details

[Tejun Heo <htejun@gmail.com>]

Greg Freemyer wrote:
> On 11/10/05, Tejun Heo <htejun@gmail.com> wrote:
> 
>>linux@horizon.com wrote:
>>
>>>Three days ago, I wrote:
>>>
>>>
>>>>I finished "badblocks -b 4096 -c 65536 -s -v -w -t random" run on 350
>>>>G of one drive without seeing problems, and am working on the other 5.
>>>>(In parallel, just to stress the driver.)
>>>
>>>
>>>My parallel -p1 badblocks runs (I shrunk the chunk size to -c 16384)
>>>finished on 3 of the 5 drives, but after 69 hours and I don't know how
>>>many passes, it's still running on one pair of drives.  Interestingly,
>>>the pair (sdc4 & sdd4) is connected to a single controller.
>>>
>>>Thus, it might not be a multiple-controller issue (I don't know how
>>>many other people have 3 Sil3132s in a system), but perhaps an issue
>>>with simultaneous activity on the 2 ports of a single controller.
>>>
>>>Is there anything else I could do to help debug this problem?  Any additional
>>>debugging I can enable?
>>>
>>>It would take me a while to clean the backups off the system and move
>>>it outside the firewall to allow remote access if someone wants access
>>>to that particular hardware, but it's just an expensive bit bucket at
>>>the moment, so ask if it would help...
>>
>>Hello, there.
>>
>>I'll soon try to tackle this one.  However, I currently have only one
>>3124 controller and one harddisk to hook to that controller, so I cannot
>>reproduce your setup over here.  Here are things that I think might help
>>in diagnosing the problem.
>>
>>* Trying other drivers
>>        * Trying the original driver.  I'll port the original driver
>>          from sii to the current tree and post the patch.
>>        * Performing similar test under Windows.
>>
>>* Ruling out disk problem
>>        * Trying other harddisks.  All harddisk drives perform error
>>          detection/correction when data are read from the media, but
>>          ruling out the possibility would still be helpful.
>>
>>* If you have log of failed sectors, finding patterns will be helpful.
>>  If the errors occur at random places, it's likely that we have
>>  controller/driver issues.  If errors are localized over multiple runs,
>>  maybe the disk is at fault.
>>
>>--
>>tejun
> 
> 
> Tejun,
> 
> I assume you saw my e-mail that with a 3112 and a single SATA drive we
> were seeing corruption as well.  That being the case I think you
> should first verify that corruption is not occuring in the single SATA
> drive case.
> 
> Our test was to create a bunch of 2 GB files on a PATA drive.
> 
> We simply used a drive with real data as the source of our test files.
> ie. IIRC: cd test_dir; dd if=/dev/hde conv=noerror,sync | split -b 2000m
> 
> Then we calculated the md5 of all the 2 GB pieces.  All of this done
> in a pure PATA setup.
> 
> Then we connected a SATA drive to a 3112 and simply copied the files
> from the PATA drive to the SATA drive and verified the md5 values.  We
> found corruption in 1 - 3% of the files copied.
> 
> FYI: The above are all very common steps for a computer forensic
> examine, thus we found this issue in our attempts to qualify the 3112
> as part of our forensic equipment.  We have not tested since 2.6.11
> and that was with a SUSE kernel.
> 

Hi,

I'll run single drive test on sil3112 tonight, but can you please try 
2.6.14?  IIRC, there have been some PCI FIFO setting change.  Hmmm.. 
oh.. it was the following commit.

---
$ git-cat-file commit e1dd23a0012c3929737798fda9fede0e783f4ff3
tree c7f808b6433ef1015f55418e7f11f432943bdefd
parent 5273a00d9c763108397658d440618f7ac3e40f83
author Jens Axboe <axboe@suse.de> 1118228545 +0200
committer Jeff Garzik <jgarzik@pobox.com> 1118300782 -0400

[PATCH] sata_sil: Fix FIFO PCI Bus Arbitration kernel oops

Correct this.
---

Jens, is it possible that above change fixes data corruption?

-- 
tejun