From: Christoph Hellwig <hch@lst.de>
To: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>,
linux-scsi@vger.kernel.org, Hannes Reinecke <hare@suse.de>,
Mike Christie <michaelc@cs.wisc.edu>,
"Martin K. Petersen" <martin.petersen@oracle.com>
Subject: Re: [PATCH 2/9] dm-mpath, scsi_dh: don't let dm detach device handlers
Date: Fri, 1 May 2015 11:20:53 +0200 [thread overview]
Message-ID: <20150501092053.GA9341@lst.de> (raw)
In-Reply-To: <20150430182153.GB30542@redhat.com>
On Thu, Apr 30, 2015 at 02:21:54PM -0400, Mike Snitzer wrote:
> > While allowing dm-mpath to attach device handlers is a functionality we need
> > for backwards compatibility reason there is no reason to reference count
> > them and detach them if dm-mpath stops using the device for some reason.
> >
> > If the device handler works for the given device it can just stay attached.
> >
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
>
> Looks good. But, unless I'm missing something, these DM and scsi_dh
> changes can be made in separate patches so that I can carry the DM
> change without needing to touch scsi_dh (SCSI maintainer boundary).
Unfortunately they can't. E.g. if we remove the detach in dm-mpath
but keep the refcounting in scsi_dh we'll leak references. Of if we
remove the request_module in dm without adding it to scsi we stop
asking for the module. So I'll need to collect ACKs from both sides
and find a suitable tree to get this in.
next prev parent reply other threads:[~2015-05-01 9:20 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-30 17:32 integrate scsi_dh better into the scsi core Christoph Hellwig
2015-04-30 17:32 ` [PATCH 1/9] dm-mpath: check kstrdup return value in parse_hw_handler Christoph Hellwig
2015-04-30 18:35 ` Hannes Reinecke
2015-05-01 13:57 ` Mike Snitzer
2015-05-01 15:07 ` Martin K. Petersen
2015-05-01 15:29 ` Martin K. Petersen
2015-04-30 17:32 ` [PATCH 2/9] dm-mpath, scsi_dh: don't let dm detach device handlers Christoph Hellwig
2015-04-30 18:21 ` Mike Snitzer
2015-05-01 9:20 ` Christoph Hellwig [this message]
2015-05-01 7:10 ` Hannes Reinecke
2015-05-01 13:58 ` Mike Snitzer
2015-05-01 15:30 ` Martin K. Petersen
2015-04-30 17:32 ` [PATCH 3/9] dm-mpath: don't call scsi_dh_attach when we want to retain the attached handler Christoph Hellwig
2015-04-30 18:25 ` Mike Snitzer
2015-05-01 7:10 ` Hannes Reinecke
2015-05-01 15:34 ` Martin K. Petersen
2015-05-01 16:46 ` Christoph Hellwig
2015-04-30 17:32 ` [PATCH 4/9] dm-mpath, scsi_dh: request scsi_dh modules in scsi_dh, not dm-mpath Christoph Hellwig
2015-04-30 18:28 ` Mike Snitzer
2015-05-01 7:11 ` Hannes Reinecke
2015-05-01 13:59 ` Mike Snitzer
2015-05-01 15:35 ` Martin K. Petersen
2015-04-30 17:32 ` [PATCH 5/9] scsi_dh: integrate into the core SCSI code Christoph Hellwig
2015-05-01 7:13 ` Hannes Reinecke
2015-05-01 15:36 ` Martin K. Petersen
2015-05-04 7:50 ` Hannes Reinecke
2015-05-05 15:25 ` Christoph Hellwig
2015-04-30 17:32 ` [PATCH 6/9] scsi_dh: move device matching to the core code Christoph Hellwig
2015-04-30 18:32 ` Mike Snitzer
2015-05-01 7:15 ` Hannes Reinecke
2015-05-01 15:39 ` Martin K. Petersen
2015-04-30 17:32 ` [PATCH 7/9] scsi_dh: kill struct scsi_dh_data Christoph Hellwig
2015-05-01 7:17 ` Hannes Reinecke
2015-05-01 15:41 ` Martin K. Petersen
2015-04-30 17:32 ` [PATCH 8/9] scsi_dh: add a common helper to get a scsi_device from a request_queue Christoph Hellwig
2015-05-01 7:18 ` Hannes Reinecke
2015-05-01 15:45 ` Martin K. Petersen
2015-04-30 17:32 ` [PATCH 9/9] scsi_dh: don't allow to detach device handlers at runtime Christoph Hellwig
2015-05-01 7:19 ` Hannes Reinecke
2015-05-01 15:46 ` Martin K. Petersen
2015-04-30 18:31 ` integrate scsi_dh better into the scsi core Mike Snitzer
2015-05-01 15:47 ` Martin K. Petersen
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