Re: [PATCH 14/26] block: move the nonrot flag to queue_limits
- To: Wouter Verhelst <w@uter.be>
- Cc: Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>, Geert Uytterhoeven <geert@linux-m68k.org>, Richard Weinberger <richard@nod.at>, Philipp Reisner <philipp.reisner@linbit.com>, Lars Ellenberg <lars.ellenberg@linbit.com>, Christoph Böhmwalder <christoph.boehmwalder@linbit.com>, Josef Bacik <josef@toxicpanda.com>, Ming Lei <ming.lei@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Jason Wang <jasowang@redhat.com>, Roger Pau Monné <roger.pau@citrix.com>, Alasdair Kergon <agk@redhat.com>, Mike Snitzer <snitzer@kernel.org>, Mikulas Patocka <mpatocka@redhat.com>, Song Liu <song@kernel.org>, Yu Kuai <yukuai3@huawei.com>, Vineeth Vijayan <vneethv@linux.ibm.com>, "Martin K. Petersen" <martin.petersen@oracle.com>, linux-m68k@lists.linux-m68k.org, linux-um@lists.infradead.org, drbd-dev@lists.linbit.com, nbd@other.debian.org, linuxppc-dev@lists.ozlabs.org, ceph-devel@vger.kernel.org, virtualization@lists.linux.dev, xen-devel@lists.xenproject.org, linux-bcache@vger.kernel.org, dm-devel@lists.linux.dev, linux-raid@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mtd@lists.infradead.org, nvdimm@lists.linux.dev, linux-nvme@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, Damien Le Moal <dlemoal@kernel.org>
- Subject: Re: [PATCH 14/26] block: move the nonrot flag to queue_limits
- From: Christoph Hellwig <hch@lst.de>
- Date: Thu, 25 Jul 2024 15:00:08 +0200
- Message-id: <[🔎] 20240725130008.GA22625@lst.de>
- In-reply-to: <[🔎] ZqI4kosy20WkLC2P@pc220518.home.grep.be>
- References: <20240617060532.127975-1-hch@lst.de> <20240617060532.127975-15-hch@lst.de> <[🔎] ZqI4kosy20WkLC2P@pc220518.home.grep.be>
On Thu, Jul 25, 2024 at 01:35:46PM +0200, Wouter Verhelst wrote:
> NBD actually exports a flag for rotational devices; it's defined in
> nbd.h in the NBD userland source as
>
> #define NBD_FLAG_ROTATIONAL (1 << 4) /* Use elevator algorithm - rotational media */
>
> which is passed in the same flags field which also contains the
> NBD_FLAG_SEND_FLUSH and NBD_FLAG_SEND_FUA flags.
>
> Perhaps we might want to look at that flag and set the device to
> rotational if it is specified?
Yes, that sounds good. Can you send a patch?
Reply to: