Re: Commit 7eaceaccab5f40 causing boot hang.

From: Jens Axboe
Date: Thu Mar 31 2011 - 05:03:01 EST


On 2011-03-30 15:52, Rob Landley wrote:
> On 03/30/2011 06:38 AM, Jens Axboe wrote:
>> On 2011-03-30 08:06, Rob Landley wrote:
>>> On 03/29/2011 10:51 AM, Pete Clements wrote:
>>>> Quoting Jens Axboe
>>>> >
>>>> > On 2011-03-29 16:13, Rob Landley wrote:
>>>> > > On 03/29/2011 08:59 AM, Jens Axboe wrote:
>>>> > >> On 2011-03-29 10:52, Rob Landley wrote:
>>>> > >>> I'm booting all this under kvm or qemu, by the way:
>>>> > >>>
>>>> > >>> qemu-system-x86_64 -m 1024 -kernel arch/x86/boot/bzImage \
>>>> > >>> -hda ~/sid.ext3 -append "root=/dev/hda rw"
>>>> > >>>
>>>> > >>> Sometimes with init=/bin/bash in that last quoted bit. The root
>>>> > >>> filesystem's debian sid but that's probably not relevant because it
>>>> > >>> worked fine with .38.
>>>> > >>
>>>> > >> Does this help?
>>>> > >>
>>>> > >> diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
>>>> > >> index 0e406d73..ca27d30 100644
>>>> > >> --- a/drivers/ide/ide-io.c
>>>> > >> +++ b/drivers/ide/ide-io.c
>>>> > >> @@ -570,8 +570,7 @@ void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
>>>> > >> spin_unlock_irqrestore(q->queue_lock, flags);
>>>> > >>
>>>> > >> /* Use 3ms as that was the old plug delay */
>>>> > >> - if (rq)
>>>> > >> - blk_delay_queue(q, 3);
>>>> > >> + blk_delay_queue(q, 3);
>>>> > >> }
>>>> > >>
>>>> > >> static int drive_is_ready(ide_drive_t *drive)
>>>> > >>
>>>> > >
>>>> > > Nope, still hung the same way.
>>>> >
>>>> > Funky. I'll try and reproduce this tonight.
>>>> >
>>>> > --
>>>> > Jens Axboe
>>>> >
>>>>
>>>> I have had a similiar problem (reported earlier) unable to boot.
>>>> With git15-18 hung with IDE drives (hda), git19-21 moved the hang down to
>>>> the IDE CDROM (hdc). Applied the above patch and now booted into git21 without
>>>> any hang and all appears ok.
>>>
>>> It may have made it better for me, it's hard to tell.
>>>
>>> I did a fresh pull, re-applied the patch, and tried again with
>>> init=/bin/sh and it booted to the shell prompt... which then hung when I
>>> did "ls -l /".
>>>
>>> If I let it boot normally, init announces itself, gives a spurious
>>> warning about a fstab field (which it's been doing for a while, my fault
>>> but harmless), then hangs.
>>>
>>>> This is i386, UP.
>>>
>>> I'm doing x86-64 SMP.
>>
>> I think we have the same issue the other location. How about this, then:
>>
>> diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
>> index 0e406d73..4978ec3 100644
>> --- a/drivers/ide/ide-io.c
>> +++ b/drivers/ide/ide-io.c
>> @@ -549,12 +549,11 @@ plug_device:
>> spin_unlock_irq(&hwif->lock);
>> ide_unlock_host(host);
>> plug_device_2:
>> + blk_delay_queue(q, queue_run_ms);
>> spin_lock_irq(q->queue_lock);
>>
>> - if (rq) {
>> + if (rq)
>> blk_requeue_request(q, rq);
>> - blk_delay_queue(q, queue_run_ms);
>> - }
>> }
>>
>> void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
>> @@ -570,8 +569,7 @@ void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
>> spin_unlock_irqrestore(q->queue_lock, flags);
>>
>> /* Use 3ms as that was the old plug delay */
>> - if (rq)
>> - blk_delay_queue(q, 3);
>> + blk_delay_queue(q, 3);
>> }
>>
>> static int drive_is_ready(ide_drive_t *drive)
>>
>
> Did a fresh pull and applied that patch. (It conflicts with your
> previous one, but looks like it includes it.)
>
> Now it hangs after the "EXT3-fs: barriers not enabled" line, doesn't
> make it to init.

I have tried hard to reproduce this, but even stock 2.6.39-rc1 works
fine for me here. Setup a KVM image with a debian 6 install, then
converted it to IDE and booting it with a custom kernel like you are.
Works fine, boots and I can do disk activity tests and it all works.

Can you send me your .config?

--
Jens Axboe

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