Messages in this thread | | | Date | Tue, 24 May 2022 07:19:26 +0200 | Subject | Re: [PATCH v5 2/7] block: allow blk-zoned devices to have non-power-of-2 zone size | From | Hannes Reinecke <> |
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On 5/23/22 18:15, Pankaj Raghav wrote: > Checking if a given sector is aligned to a zone is a common > operation that is performed for zoned devices. Add > blk_queue_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 based logic in the block layer using the helpers wherever > possible. > > The only hot path affected by this change for power_of_2 zoned devices > is in blk_check_zone_append() but blk_queue_is_zone_start() helper is > used to optimize the calculation for po2 zone sizes. Note that the append > path cannot be accessed by direct raw access to the block device but only > through a filesystem abstraction. > > Finally, allow non power of 2 zoned devices provided that their zone > capacity and zone size are equal. The main motivation to allow non > power_of_2 zoned device is to remove the unmapped LBA between zcap and > zsze for devices that cannot have a power_of_2 zcap. > > Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> > Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> > --- > block/blk-core.c | 3 +-- > block/blk-zoned.c | 26 ++++++++++++++++++++------ > include/linux/blkdev.h | 21 +++++++++++++++++++++ > 3 files changed, 42 insertions(+), 8 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index bc0506772152..bf1eae142118 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -630,8 +630,7 @@ 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 (pos & (blk_queue_zone_sectors(q) - 1) || > - !blk_queue_zone_is_seq(q, pos)) > + if (!blk_queue_is_zone_start(q, pos) || !blk_queue_zone_is_seq(q, pos)) > return BLK_STS_IOERR; > > /* > diff --git a/block/blk-zoned.c b/block/blk-zoned.c > index e7eec513dd42..665993b13668 100644 > --- a/block/blk-zoned.c > +++ b/block/blk-zoned.c > @@ -288,10 +288,10 @@ int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op, > return -EINVAL; > > /* Check alignment (handle eventual smaller last zone) */ > - if (sector & (zone_sectors - 1)) > + if (!blk_queue_is_zone_start(q, sector)) > return -EINVAL; > > - if ((nr_sectors & (zone_sectors - 1)) && end_sector != capacity) > + if (!blk_queue_is_zone_start(q, nr_sectors) && end_sector != capacity) > return -EINVAL; > > /* > @@ -489,14 +489,28 @@ 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 zone size", disk->disk_name); > + return -ENODEV; > + } > + > + /* > + * Don't allow zoned device with non power_of_2 zone size with > + * zone capacity less than zone size. > + */ > + if (!is_power_of_2(zone->len) && > + zone->capacity < zone->len) { > + pr_warn("%s: Invalid zone capacity for non power of 2 zone size", > + disk->disk_name); > return -ENODEV; > } > > args->zone_sectors = zone->len; > - args->nr_zones = (capacity + zone->len - 1) >> ilog2(zone->len); > + /* > + * Division is used to calculate nr_zones for both power_of_2 > + * and non power_of_2 zone sizes as it is not in the hot path. > + */ > + 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 c4e4c7071b7b..f5c7a41032ba 100644 > --- a/include/linux/blkdev.h > +++ b/include/linux/blkdev.h > @@ -676,6 +676,21 @@ static inline unsigned int blk_queue_zone_no(struct request_queue *q, > return div64_u64(sector, zone_sectors); > } > > +static inline bool blk_queue_is_zone_start(struct request_queue *q, sector_t sec) > +{ > + sector_t zone_sectors = blk_queue_zone_sectors(q); > + u64 remainder = 0; > + > + if (!blk_queue_is_zoned(q)) > + return false; > +
Not sure if we need this here; surely blk_queue_zone_sectors() will already barf, and none of the callers did this check.
> + if (is_power_of_2(zone_sectors)) > + return IS_ALIGNED(sec, zone_sectors); > + > + div64_u64_rem(sec, zone_sectors, &remainder); > + return remainder == 0; > +} > + > static inline bool blk_queue_zone_is_seq(struct request_queue *q, > sector_t sector) > { > @@ -722,6 +737,12 @@ static inline unsigned int blk_queue_zone_no(struct request_queue *q, > { > return 0; > } > + > +static inline bool blk_queue_is_zone_start(struct request_queue *q, sector_t sec) > +{ > + return false; > +} > + > static inline unsigned int queue_max_open_zones(const struct request_queue *q) > { > return 0; Otherwise looks good.
Cheers,
Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
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