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Content-Language: en-US To: Nitesh Shetty , Jens Axboe , Jonathan Corbet , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, Keith Busch , Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni , Alexander Viro , Christian Brauner Cc: martin.petersen@oracle.com, mcgrof@kernel.org, gost.dev@samsung.com, Anuj Gupta , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org References: <20230906163844.18754-1-nj.shetty@samsung.com> <20230906163844.18754-3-nj.shetty@samsung.com> From: Hannes Reinecke In-Reply-To: <20230906163844.18754-3-nj.shetty@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230906_223919_474576_4FE433F2 X-CRM114-Status: GOOD ( 15.37 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 9/6/23 18:38, Nitesh Shetty wrote: > We add two new opcode REQ_OP_COPY_SRC, REQ_OP_COPY_DST. > Since copy is a composite operation involving src and dst sectors/lba, > each needs to be represented by a separate bio to make it compatible > with device mapper. > We expect caller to take a plug and send bio with source information, > followed by bio with destination information. > Once the src bio arrives we form a request and wait for destination > bio. Upon arrival of destination we merge these two bio's and send > corresponding request down to device driver. > > Signed-off-by: Nitesh Shetty > Signed-off-by: Anuj Gupta > --- > block/blk-core.c | 7 +++++++ > block/blk-merge.c | 41 +++++++++++++++++++++++++++++++++++++++ > block/blk.h | 16 +++++++++++++++ > block/elevator.h | 1 + > include/linux/bio.h | 6 +----- > include/linux/blk_types.h | 10 ++++++++++ > 6 files changed, 76 insertions(+), 5 deletions(-) > Having two separate bios is okay, and what one would expect. What is slightly strange is the merging functionality; That could do with some more explanation why this approach was taken. And also some checks in the merging code to avoid merging non-copy offload bios. Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman