Re: Commit 7eaceaccab5f40 causing boot hang.

From: Jens Axboe
Date: Wed Mar 30 2011 - 07:38:34 EST


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)

--
Jens Axboe

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