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

James Bottomley
2007-11-24T13:27:09Z

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.

James