From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89E4AECAAD6 for ; Fri, 26 Aug 2022 20:06:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237685AbiHZUGS (ORCPT ); Fri, 26 Aug 2022 16:06:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229561AbiHZUGQ (ORCPT ); Fri, 26 Aug 2022 16:06:16 -0400 Received: from out0.migadu.com (out0.migadu.com [IPv6:2001:41d0:2:267::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3094431EE0; Fri, 26 Aug 2022 13:06:13 -0700 (PDT) Message-ID: <1dc85f87-7146-ccd2-bbf4-e3077dd7a548@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1661544371; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PNk1kll23rwJYMsqgLsvF7iQCb4ky0T3/2VgqDe/eTw=; b=dGlANpuf+dyysAHNTCQkld7zCMnQBzdsup6joAOWrC8cpsUqkoSGuLWQC0YwXko3DvA8D+ pqOXZCtfDLxV2cUFqtOS8vCd7awM2XEpKEfgFWI7fn7ZVUlhnKEEohQqz9IUmU/47ii7LR sUeVGKoKefsvYqoDp4J/fSX9kz0e6sM= Date: Fri, 26 Aug 2022 14:06:07 -0600 MIME-Version: 1.0 Subject: Re: [PATCH v12 03/13] block: allow blk-zoned devices to have non-power-of-2 zone size Content-Language: en-US To: Pankaj Raghav , agk@redhat.com, snitzer@kernel.org, axboe@kernel.dk, damien.lemoal@opensource.wdc.com, hch@lst.de Cc: pankydev8@gmail.com, Johannes.Thumshirn@wdc.com, linux-block@vger.kernel.org, dm-devel@redhat.com, hare@suse.de, jaegeuk@kernel.org, linux-kernel@vger.kernel.org, matias.bjorling@wdc.com, gost.dev@samsung.com, bvanassche@acm.org, linux-nvme@lists.infradead.org, Luis Chamberlain References: <20220823121859.163903-1-p.raghav@samsung.com> <20220823121859.163903-4-p.raghav@samsung.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Jonathan Derrick In-Reply-To: <20220823121859.163903-4-p.raghav@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/23/2022 6:18 AM, Pankaj Raghav wrote: > Checking if a given sector is aligned to a zone is a common > operation that is performed for zoned devices. Add > bdev_is_zone_start helper to check for this instead of opencoding it > everywhere. > > Convert the calculations on zone size to be generic instead of relying on > power-of-2(po2) based arithmetic in the block layer using the helpers > wherever possible. > > The only hot path affected by this change for zoned devices with po2 > zone size is in blk_check_zone_append() but bdev_is_zone_start() helper is > used to optimize the calculation for po2 zone sizes. > > Finally, allow zoned devices with non po2 zone sizes provided that their > zone capacity and zone size are equal. The main motivation to allow zoned > devices with non po2 zone size is to remove the unmapped LBA between > zone capcity and zone size for devices that cannot have a po2 zone > capacity. > > Reviewed-by: Luis Chamberlain > Reviewed-by: Hannes Reinecke > Reviewed-by: Bart Van Assche > Signed-off-by: Pankaj Raghav > --- > block/blk-core.c | 2 +- > block/blk-zoned.c | 24 ++++++++++++++++++------ > include/linux/blkdev.h | 30 ++++++++++++++++++++++++++++++ > 3 files changed, 49 insertions(+), 7 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index a0d1104c5590..1cb519220ffb 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -563,7 +563,7 @@ static inline blk_status_t blk_check_zone_append(struct request_queue *q, > return BLK_STS_NOTSUPP; > > /* The bio sector must point to the start of a sequential zone */ > - if (bio->bi_iter.bi_sector & (bdev_zone_sectors(bio->bi_bdev) - 1) || > + if (!bdev_is_zone_start(bio->bi_bdev, bio->bi_iter.bi_sector) || > !bio_zone_is_seq(bio)) > return BLK_STS_IOERR; > > diff --git a/block/blk-zoned.c b/block/blk-zoned.c > index dce9c95b4bcd..6806c69c81dc 100644 > --- a/block/blk-zoned.c > +++ b/block/blk-zoned.c > @@ -285,10 +285,10 @@ int blkdev_zone_mgmt(struct block_device *bdev, enum req_op op, > return -EINVAL; > > /* Check alignment (handle eventual smaller last zone) */ > - if (sector & (zone_sectors - 1)) > + if (!bdev_is_zone_start(bdev, sector)) > return -EINVAL; > > - if ((nr_sectors & (zone_sectors - 1)) && end_sector != capacity) > + if (!bdev_is_zone_start(bdev, nr_sectors) && end_sector != capacity) > return -EINVAL; > > /* > @@ -486,14 +486,26 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx, > * smaller last zone. > */ > if (zone->start == 0) { > - if (zone->len == 0 || !is_power_of_2(zone->len)) { > - pr_warn("%s: Invalid zoned device with non power of two zone size (%llu)\n", > - disk->disk_name, zone->len); > + if (zone->len == 0) { > + pr_warn("%s: Invalid zero zone size", disk->disk_name); > + return -ENODEV; > + } > + > + /* > + * Non power-of-2 zone size support was added to remove the > + * gap between zone capacity and zone size. Though it is technically > + * possible to have gaps in a non power-of-2 device, Linux requires > + * the zone size to be equal to zone capacity for non power-of-2 > + * zoned devices. > + */ > + if (!is_power_of_2(zone->len) && zone->capacity < zone->len) { > + pr_err("%s: Invalid zone capacity %lld with non power-of-2 zone size %lld", > + disk->disk_name, zone->capacity, zone->len); > return -ENODEV; > } > > args->zone_sectors = zone->len; > - args->nr_zones = (capacity + zone->len - 1) >> ilog2(zone->len); > + args->nr_zones = div64_u64(capacity + zone->len - 1, zone->len); > } else if (zone->start + args->zone_sectors < capacity) { > if (zone->len != args->zone_sectors) { > pr_warn("%s: Invalid zoned device with non constant zone size\n", > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h > index 84e7881262e3..d0d66a0db224 100644 > --- a/include/linux/blkdev.h > +++ b/include/linux/blkdev.h > @@ -704,6 +704,30 @@ static inline unsigned int disk_zone_no(struct gendisk *disk, sector_t sector) > return div64_u64(sector, zone_sectors); > } > > +static inline sector_t bdev_offset_from_zone_start(struct block_device *bdev, > + sector_t sec) > +{ > + sector_t zone_sectors = bdev_zone_sectors(bdev); > + u64 remainder = 0; > + > + if (!bdev_is_zoned(bdev)) > + return 0; See below > + > + if (is_power_of_2(zone_sectors)) > + return sec & (zone_sectors - 1); > + > + div64_u64_rem(sec, zone_sectors, &remainder); > + return remainder; > +} > + > +static inline bool bdev_is_zone_start(struct block_device *bdev, sector_t sec) > +{ > + if (!bdev_is_zoned(bdev)) > + return false; Duplicating the same check above, and the check above is less clear in the case of !zoned since it returns 0 and not some warning that makes sense in the case of zoned check on !zoned bdev. Can you simply exclude above check? > + > + return bdev_offset_from_zone_start(bdev, sec) == 0; > +} > + > static inline bool disk_zone_is_seq(struct gendisk *disk, sector_t sector) > { > if (!blk_queue_is_zoned(disk->queue)) > @@ -748,6 +772,12 @@ static inline unsigned int disk_zone_no(struct gendisk *disk, sector_t sector) > { > return 0; > } > + > +static inline bool bdev_is_zone_start(struct block_device *bdev, sector_t sec) > +{ > + return false; > +} > + > static inline unsigned int bdev_max_open_zones(struct block_device *bdev) > { > return 0;