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To: Nitesh Shetty Cc: Damien Le Moal , Jens Axboe , Jonathan Corbet , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Keith Busch , Christoph Hellwig , 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> <20240529061736.rubnzwkkavgsgmie@nj.shetty@samsung.com> <9f1ec1c1-e1b8-48ac-b7ff-8efb806a1bc8@kernel.org> <665850bd.050a0220.a5e6b.5b72SMTPIN_ADDED_BROKEN@mx.google.com> <6659b691.630a0220.90195.d0ebSMTPIN_ADDED_BROKEN@mx.google.com> Content-Language: en-US From: Bart Van Assche In-Reply-To: <6659b691.630a0220.90195.d0ebSMTPIN_ADDED_BROKEN@mx.google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable On 5/31/24 03:17, Nitesh Shetty wrote: > I see the following challenges with bio-chained approach. > 1. partitioned device: > =C2=A0=C2=A0=C2=A0=C2=A0We need to add the code which iterates over al= l bios and adjusts > =C2=A0=C2=A0=C2=A0=C2=A0the sectors offsets. > 2. dm/stacked device: > =C2=A0=C2=A0=C2=A0=C2=A0We need to make major changes in dm, such as a= llocating cloned > =C2=A0=C2=A0=C2=A0=C2=A0bios, IO splits, IO offset mappings. All of wh= ich need to > =C2=A0=C2=A0=C2=A0=C2=A0iterate over chained BIOs. >=20 > Overall with chained BIOs we need to add a special handling only for co= py > to iterate over chained BIOs and do the same thing which is being done > for single BIO at present. > Or am I missing something here ? Hmm ... aren't chained bios submitted individually? See e.g. bio_chain_and_submit(). In other words, it shouldn't be necessary to add any code that iterates over bio chains. Thanks, Bart.