From: Tejun Heo <htejun@gmail.com>
To: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mark Lord <liml@rtr.ca>, Matthew Wilcox <matthew@wil.cx>,
linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org,
Jeff Garzik <jeff@garzik.org>
Subject: Re: ata_ram driver
Date: Fri, 07 Mar 2008 09:43:22 +0900 [thread overview]
Message-ID: <47D08FAA.7070001@gmail.com> (raw)
In-Reply-To: <1204850398.3062.111.camel@localhost.localdomain>
James Bottomley wrote:
> On Fri, 2008-03-07 at 09:28 +0900, Tejun Heo wrote:
>> James Bottomley wrote:
>>>> Yeap, sure. It's the combination of things that always made me put this
>>>> off. Is there a function I can call to just shutdown the host instead
>>>> of destroying it?
>>> Not really ... the process of unbinding the ULDs causes their remove
>>> methods to call shudown. It is possible to separate this in the ULDS;
>>> but the original design was to make remove and shutdown be similar for
>>> the very reason that if you're removing the driver with unflushed data
>>> in the cache, we'd really like it flushed (flush is called from
>>> shutdown) because you have no way to talk to the device after this
>>> without reinserting the driver.
>> The problem is that libata EH and other stuff aren't ready to let go of
>> the SCSI host up until the last moment and that last moment can't be
>> moved before SCSI host destruction because shutdown sequence (flush and
>> spindown) requires live EH. I think this can be solved by shooting down
>> individual sdev's instead of destroying the scsi_host.
>
> Basically what scsi_scan.c:scsi_forget_host() does? It's used
> internally at the moment, but I suppose we could export it.
Yeap, exactly. I'll prep a patch after breakfast.
--
tejun
next prev parent reply other threads:[~2008-03-07 0:43 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-22 20:09 ata_ram driver Matthew Wilcox
2008-02-22 21:27 ` Mark Lord
2008-03-06 8:21 ` Tejun Heo
2008-03-06 15:28 ` James Bottomley
2008-03-06 23:55 ` Tejun Heo
2008-03-07 0:01 ` James Bottomley
2008-03-07 0:13 ` Tejun Heo
2008-03-07 0:22 ` James Bottomley
2008-03-07 0:28 ` Tejun Heo
2008-03-07 0:39 ` James Bottomley
2008-03-07 0:43 ` Tejun Heo [this message]
2008-03-07 3:08 ` [PATCH 1/2] scsi: export scsi_forget_host() Tejun Heo
2008-03-07 3:11 ` [PATCH 2/2] libata: kill SCSI devices before detaching ata_host Tejun Heo
2008-03-07 2:16 ` ata_ram driver Jeff Garzik
2008-03-07 2:44 ` James Bottomley
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