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From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: michaelc@cs.wisc.edu, linux-scsi@vger.kernel.org,
	target-devel@vger.kernel.org, ceph-devel@vger.kernel.org,
	axboe@kernel.dk, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] block: add function to issue compare and write
Date: Fri, 17 Oct 2014 19:38:37 -0400	[thread overview]
Message-ID: <yq1egu62rnm.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <20141017095555.GA360@infradead.org> (Christoph Hellwig's message of "Fri, 17 Oct 2014 02:55:55 -0700")

>>>>> "Christoph" == Christoph Hellwig <hch@infradead.org> writes:

Christoph> We already have req->cmd_type which actually is a fairly good
Christoph> description of what we get except for REQ_TYPE_FS, which is a
Christoph> horrible overload using req->cmd_flags.

Christoph> Given that you're just one of many currently ongoing patches
Christoph> to add more flags here I think you need to byte the bullet
Christoph> and fix this up by replacing REQ_TYPE_FS with:

Christoph> REQ_TYPE_WRITE REQ_TYPE_READ REQ_TYPE_FLUSH REQ_TYPE_DISCARD
Christoph> REQ_TYPE_WRITE_SAME REQ_TYPE_CMP_AND_WRITE

The problem with this is that, as it stands, a bio has no type. And it
would suck if we couldn't keep bio rw and request flags in sync.

I wonder if it would make more sense to move the remaining rq types to
cmd_flags after I'm done with the 64-bit conversion?

-- 
Martin K. Petersen	Oracle Linux Engineering

  reply	other threads:[~2014-10-17 23:38 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-16  5:37 [PATCH 0/5] block/scsi/lio support for COMPARE_AND_WRITE michaelc
2014-10-16  5:37 ` [PATCH 1/5] block: set the nr of sectors a dev can compare and write atomically michaelc
2014-10-16  5:37 ` [PATCH 2/5] block: add function to issue compare and write michaelc
2014-10-17  9:55   ` Christoph Hellwig
2014-10-17 23:38     ` Martin K. Petersen [this message]
2014-10-18 15:16       ` Christoph Hellwig
2014-10-16  5:37 ` [PATCH 3/5] scsi: add support for COMPARE_AND_WRITE michaelc
2014-12-18  0:23   ` Elliott, Robert (Server Storage)
2014-10-16  5:37 ` [PATCH 4/5] lio: use REQ_COMPARE_AND_WRITE if supported michaelc
2014-10-16  5:37 ` [PATCH 5/5] lio iblock: add support for REQ_CMP_AND_WRITE michaelc
2014-10-16 10:39 ` [PATCH 0/5] block/scsi/lio support for COMPARE_AND_WRITE Douglas Gilbert
2014-10-16 20:01   ` Douglas Gilbert
2014-10-16 20:12     ` Elliott, Robert (Server Storage)
2014-10-17  6:02     ` Hannes Reinecke
2014-10-18  8:11 ` Bart Van Assche
2014-10-18 20:32   ` Mike Christie
2014-10-20  7:18     ` Sagi Grimberg

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