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To: Christoph Hellwig Cc: Nitesh Shetty , Damien Le Moal , Jens Axboe , Jonathan Corbet , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Keith Busch , Sagi Grimberg , Chaitanya Kulkarni , Alexander Viro , Christian Brauner , Jan Kara , martin.petersen@oracle.com, david@fromorbit.com, hare@suse.de, damien.lemoal@opensource.wdc.com, anuj20.g@samsung.com, joshi.k@samsung.com, nitheshshetty@gmail.com, gost.dev@samsung.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, dm-devel@lists.linux.dev, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org References: <20240520102033.9361-1-nj.shetty@samsung.com> <20240520102033.9361-3-nj.shetty@samsung.com> <9f1ec1c1-e1b8-48ac-b7ff-8efb806a1bc8@kernel.org> <665850bd.050a0220.a5e6b.5b72SMTPIN_ADDED_BROKEN@mx.google.com> <20240601055931.GB5772@lst.de> <20240604044042.GA29094@lst.de> Content-Language: en-US From: Bart Van Assche In-Reply-To: <20240604044042.GA29094@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240604_044451_214911_7D72A006 X-CRM114-Status: GOOD ( 12.49 ) 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 6/3/24 21:40, Christoph Hellwig wrote: > There is no requirement to process them synchronously, there is just > a requirement to preserve the order. Note that my suggestion a few > arounds ago also included a copy id to match them up. If we don't > need that I'm happy to leave it away. If need it it to make stacking > drivers' lifes easier that suggestion still stands. Including an ID in REQ_OP_COPY_DST and REQ_OP_COPY_SRC operations sounds much better to me than abusing the merge infrastructure for combining these two operations into a single request. With the ID-based approach stacking drivers are allowed to process copy bios asynchronously and it is no longer necessary to activate merging for copy operations if merging is disabled (QUEUE_FLAG_NOMERGES). Thanks, Bart.