Re: [dm-devel] [PATCH 0/15] copy offload patches

From: Mike Christie <michaelc@cs.wisc.edu>
To: device-mapper development <dm-devel@redhat.com>,
	Mikulas Patocka <mpatocka@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>, Mike Snitzer <msnitzer@redhat.com>,
	linux-scsi@vger.kernel.org,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	"James E.J. Bottomley" <JBottomley@odin.com>,
	linux-kernel@vger.kernel.org, linux-block@vger.kernel.org
Subject: Re: [dm-devel] [PATCH 0/15] copy offload patches
Date: Thu, 10 Dec 2015 19:46:06 -0600	[thread overview]
Message-ID: <566A2ADE.7010504@cs.wisc.edu> (raw)
In-Reply-To: <yq1r3iuylwd.fsf@sermon.lab.mkp.net>

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On 12/10/2015 04:33 PM, Martin K. Petersen wrote:
> Mike: What's your status? I'm afraid I didn't get a chance to dig very
> deep in your series since it coincided with me scrambling to sort out
> SCSI for 4.4. Do you think there's a chance we could get your patches in
> shape for 4.5? Is there an up-to-date tree I can look at?

I just had 2 review comments left:

1. Originally, I had left REQ_FLUSH a flag. Christoph suggested to break
it up into a op and flag:

http://marc.info/?l=linux-scsi&m=144689113106515&w=2

I started this and messed up :) Was going to retry next week.

2. Start REQ_OP_READ off at non-zero to try and shake out code that was
not converted.

There are a several places where we assume reads are zero and writes are
1 for things like indexing in arrays (like blktrace's ddir_act or dm
starts), passing into block functions (like nvme_alloc_request's call of
blk_mq_alloc_request), and if/else's. I am not done fixing all of them
and testing.

Also, the btrfs patch is really large (1000 lines) because that code
base is so large and there were so many places we passed around rw to
through multiple functions. I wanted to try and break it up, so it would
be easier for those guys to review.

I attached a tarball of the patches here.

Patches made against Jens's linux-block tree:
https://git.kernel.org/cgit/linux/kernel/git/axboe/linux-block.git/

for-next branch. Last commit was:

commit 4c93772e14f0b20f38462c395336a6f5c8c7727d
Merge: e1b98c0 8c0b391
Author: Jens Axboe <axboe@fb.com>
Date:   Wed Dec 9 10:57:21 2015 -0700

    Merge branch 'for-4.5/nvme' into for-next

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