From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: [PATCH v3 4/6] block: allow 'chunk_sectors' to be non-power-of-2 Date: Tue, 22 Sep 2020 15:30:34 -0400 Message-ID: References: <20200922023251.47712-1-snitzer@redhat.com> <20200922023251.47712-5-snitzer@redhat.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20200922023251.47712-5-snitzer@redhat.com> (Mike Snitzer's message of "Mon, 21 Sep 2020 22:32:49 -0400") To: Mike Snitzer Cc: Jens Axboe , Ming Lei , Vijayendra Suman , dm-devel@redhat.com, linux-block@vger.kernel.org List-Id: dm-devel.ids Mike, > It is possible, albeit more unlikely, for a block device to have a non > power-of-2 for chunk_sectors (e.g. 10+2 RAID6 with 128K chunk_sectors, > which results in a full-stripe size of 1280K. This causes the RAID6's > io_opt to be advertised as 1280K, and a stacked device _could_ then be > made to use a blocksize, aka chunk_sectors, that matches non > power-of-2 io_opt of underlying RAID6 -- resulting in stacked device's > chunk_sectors being a non power-of-2). > > Update blk_queue_chunk_sectors() and blk_max_size_offset() to > accommodate drivers that need a non power-of-2 chunk_sectors. Reviewed-by: Martin K. Petersen -- Martin K. Petersen Oracle Linux Engineering