[PATCH v2 01/11] block: make blkdev_nr_zones and blk_queue_zone_no generic for npo2 zsze

[PATCH v2 01/11] block: make blkdev_nr_zones and blk_queue_zone_no generic for npo2 zsze

[Pankaj Raghav]

Adapt blkdev_nr_zones and blk_queue_zone_no function so that it can
also work for non-power-of-2 zone sizes.

As the existing deployments of zoned devices had power-of-2
assumption, power-of-2 optimized calculation is kept for those devices.

There are no direct hot paths modified and the changes just
introduce one new branch per call.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed by: Adam Manzanares <a.manzanares@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 block/blk-zoned.c      | 14 +++++++++++---
 include/linux/blkdev.h |  8 +++++++-
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 38cd840d8..a09a2eef9 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -111,16 +111,24 @@ EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);
  * blkdev_nr_zones - Get number of zones
  * @disk:	Target gendisk
  *
- * Return the total number of zones of a zoned block device.  For a block
- * device without zone capabilities, the number of zones is always 0.
+ * Return the total number of zones of a zoned block device, including the
+ * eventual small last zone if present.
+ * For a block device without zone capabilities, the number of zones
+ * is always 0.
  */
 unsigned int blkdev_nr_zones(struct gendisk *disk)
 {
 	sector_t zone_sectors = blk_queue_zone_sectors(disk->queue);
+	sector_t capacity = get_capacity(disk);
 
 	if (!blk_queue_is_zoned(disk->queue))
 		return 0;
-	return (get_capacity(disk) + zone_sectors - 1) >> ilog2(zone_sectors);
+
+	if (is_power_of_2(zone_sectors))
+		return (capacity + zone_sectors - 1) >>
+		       ilog2(zone_sectors);
+
+	return div64_u64(capacity + zone_sectors - 1, zone_sectors);
 }
 EXPORT_SYMBOL_GPL(blkdev_nr_zones);
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1b24c1fb3..22fe512ee 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -675,9 +675,15 @@ static inline unsigned int blk_queue_nr_zones(struct request_queue *q)
 static inline unsigned int blk_queue_zone_no(struct request_queue *q,
 					     sector_t sector)
 {
+	sector_t zone_sectors = blk_queue_zone_sectors(q);
+
 	if (!blk_queue_is_zoned(q))
 		return 0;
-	return sector >> ilog2(q->limits.chunk_sectors);
+
+	if (is_power_of_2(zone_sectors))
+		return sector >> ilog2(zone_sectors);
+
+	return div64_u64(sector, zone_sectors);
 }
 
 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
-- 
2.25.1

[PATCH v2 02/11] block: allow blk-zoned devices to have non-power-of-2 zone size

[Pankaj Raghav]

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      | 27 +++++++++++++++++++++------
 include/linux/blkdev.h | 22 ++++++++++++++++++++++
 3 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index f305cb66c..b7051b7ea 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -634,8 +634,7 @@ 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 a09a2eef9..4a90a999c 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -290,10 +290,10 @@ 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;
 
 	/*
@@ -491,14 +491,29 @@ 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 zoned size with non power of 2 zone size and zone capacity < 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 22fe512ee..32d7bd7b1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -686,6 +686,22 @@ 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;
+
+	if (is_power_of_2(zone_sectors))
+		return IS_ALIGNED(sec, zone_sectors);
+
+	div64_u64_rem(sec, zone_sectors, &remainder);
+	/* if there is a remainder, then the sector is not aligned */
+	return remainder == 0;
+}
+
 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
 					 sector_t sector)
 {
@@ -732,6 +748,12 @@ 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;
-- 
2.25.1

[PATCH v2 03/11] nvme: zns: Allow ZNS drives that have non-power_of_2 zone size

[Pankaj Raghav]

Remove the condition which disallows non-power_of_2 zone size ZNS drive
to be updated and use generic method to calculate number of zones
instead of relying on log and shift based calculation on zone size.

The power_of_2 calculation has been replaced directly with generic
calculation without special handling. Both modified functions are not
used in hot paths, they are only used during initialization &
revalidation of the ZNS device.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed by: Adam Manzanares <a.manzanares@samsung.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 drivers/nvme/host/zns.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/nvme/host/zns.c b/drivers/nvme/host/zns.c
index 9f81beb4d..65d2aa68a 100644
--- a/drivers/nvme/host/zns.c
+++ b/drivers/nvme/host/zns.c
@@ -101,13 +101,6 @@ int nvme_update_zone_info(struct nvme_ns *ns, unsigned lbaf)
 	}
 
 	ns->zsze = nvme_lba_to_sect(ns, le64_to_cpu(id->lbafe[lbaf].zsze));
-	if (!is_power_of_2(ns->zsze)) {
-		dev_warn(ns->ctrl->device,
-			"invalid zone size:%llu for namespace:%u\n",
-			ns->zsze, ns->head->ns_id);
-		status = -ENODEV;
-		goto free_data;
-	}
 
 	blk_queue_set_zoned(ns->disk, BLK_ZONED_HM);
 	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
@@ -128,8 +121,13 @@ static void *nvme_zns_alloc_report_buffer(struct nvme_ns *ns,
 	const size_t min_bufsize = sizeof(struct nvme_zone_report) +
 				   sizeof(struct nvme_zone_descriptor);
 
+	/*
+	 * Division is used to calculate nr_zones with no special handling
+	 * for power of 2 zone sizes as this function is not invoked in a
+	 * hot path
+	 */
 	nr_zones = min_t(unsigned int, nr_zones,
-			 get_capacity(ns->disk) >> ilog2(ns->zsze));
+			 div64_u64(get_capacity(ns->disk), ns->zsze));
 
 	bufsize = sizeof(struct nvme_zone_report) +
 		nr_zones * sizeof(struct nvme_zone_descriptor);
@@ -182,6 +180,7 @@ int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
 	int ret, zone_idx = 0;
 	unsigned int nz, i;
 	size_t buflen;
+	u64 remainder = 0;
 
 	if (ns->head->ids.csi != NVME_CSI_ZNS)
 		return -EINVAL;
@@ -197,7 +196,14 @@ int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector,
 	c.zmr.zrasf = NVME_ZRASF_ZONE_REPORT_ALL;
 	c.zmr.pr = NVME_REPORT_ZONE_PARTIAL;
 
-	sector &= ~(ns->zsze - 1);
+	/*
+	 * rounddown the sector value to the nearest zone size. roundown macro
+	 * provided in math.h will not work for 32 bit architectures.
+	 * Division is used here with no special handling for power of 2
+	 * zone sizes as this function is not invoked in a hot path
+	 */
+	div64_u64_rem(sector, ns->zsze, &remainder);
+	sector -= remainder;
 	while (zone_idx < nr_zones && sector < get_capacity(ns->disk)) {
 		memset(report, 0, buflen);
 
-- 
2.25.1

[PATCH v2 04/11] nvmet: Allow ZNS target to support non-power_of_2 zone sizes

[Pankaj Raghav]

A generic bdev_zone_no helper is added to calculate zone number for a given
sector in a block device. This helper internally uses blk_queue_zone_no to
find the zone number.

Use the helper bdev_zone_no() to calculate nr of zones. This let's us
make modifications to the math if needed in one place and adds now
support for npo2 zone devices.

Reviewed by: Adam Manzanares <a.manzanares@samsung.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 drivers/nvme/target/zns.c | 2 +-
 include/linux/blkdev.h    | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/zns.c b/drivers/nvme/target/zns.c
index 82b61acf7..5516dd6cc 100644
--- a/drivers/nvme/target/zns.c
+++ b/drivers/nvme/target/zns.c
@@ -242,7 +242,7 @@ static unsigned long nvmet_req_nr_zones_from_slba(struct nvmet_req *req)
 	unsigned int sect = nvmet_lba_to_sect(req->ns, req->cmd->zmr.slba);
 
 	return blkdev_nr_zones(req->ns->bdev->bd_disk) -
-		(sect >> ilog2(bdev_zone_sectors(req->ns->bdev)));
+	       bdev_zone_no(req->ns->bdev, sect);
 }
 
 static unsigned long get_nr_zones_from_buf(struct nvmet_req *req, u32 bufsize)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 32d7bd7b1..967790f51 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1370,6 +1370,13 @@ static inline sector_t bdev_zone_sectors(struct block_device *bdev)
 	return 0;
 }
 
+static inline unsigned int bdev_zone_no(struct block_device *bdev, sector_t sec)
+{
+	struct request_queue *q = bdev_get_queue(bdev);
+
+	return blk_queue_zone_no(q, sec);
+}
+
 static inline unsigned int bdev_max_open_zones(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
-- 
2.25.1

[PATCH v2 05/11] btrfs: zoned: Cache superblock location in btrfs_zoned_device_info

[Pankaj Raghav]

Instead of calculating the superblock location every time, cache the
superblock zone location in btrfs_zoned_device_info struct and use it to
locate the zone index.

The functions such as btrfs_sb_log_location_bdev() and
btrfs_reset_sb_log_zones() which work directly on block_device shall
continue to use the sb_zone_number because btrfs_zoned_device_info
struct might not have been initialized at that point.

This patch will enable non power-of-2 zoned devices to not perform
division to lookup superblock and its mirror location.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 fs/btrfs/zoned.c | 13 +++++++++----
 fs/btrfs/zoned.h |  1 +
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 06f22c021..e8c7cebb2 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -511,6 +511,11 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache)
 			   max_active_zones - nactive);
 	}
 
+	/* Cache the sb zone number */
+	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; ++i) {
+		zone_info->sb_zone_location[i] =
+			sb_zone_number(zone_info->zone_size_shift, i);
+	}
 	/* Validate superblock log */
 	nr_zones = BTRFS_NR_SB_LOG_ZONES;
 	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
@@ -518,7 +523,7 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache)
 		u64 sb_wp;
 		int sb_pos = BTRFS_NR_SB_LOG_ZONES * i;
 
-		sb_zone = sb_zone_number(zone_info->zone_size_shift, i);
+		sb_zone = zone_info->sb_zone_location[i];
 		if (sb_zone + 1 >= zone_info->nr_zones)
 			continue;
 
@@ -866,7 +871,7 @@ int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
 		return 0;
 	}
 
-	zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
+	zone_num = zinfo->sb_zone_location[mirror];
 	if (zone_num + 1 >= zinfo->nr_zones)
 		return -ENOENT;
 
@@ -883,7 +888,7 @@ static inline bool is_sb_log_zone(struct btrfs_zoned_device_info *zinfo,
 	if (!zinfo)
 		return false;
 
-	zone_num = sb_zone_number(zinfo->zone_size_shift, mirror);
+	zone_num = zinfo->sb_zone_location[mirror];
 	if (zone_num + 1 >= zinfo->nr_zones)
 		return false;
 
@@ -1011,7 +1016,7 @@ u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
 			u32 sb_zone;
 			u64 sb_pos;
 
-			sb_zone = sb_zone_number(shift, i);
+			sb_zone = zinfo->sb_zone_location[i];
 			if (!(end <= sb_zone ||
 			      sb_zone + BTRFS_NR_SB_LOG_ZONES <= begin)) {
 				have_sb = true;
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 10f31d1c8..694ab6d1e 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -27,6 +27,7 @@ struct btrfs_zoned_device_info {
 	unsigned long *active_zones;
 	struct blk_zone *zone_cache;
 	struct blk_zone sb_zones[2 * BTRFS_SUPER_MIRROR_MAX];
+	u32 sb_zone_location[BTRFS_SUPER_MIRROR_MAX];
 };
 
 #ifdef CONFIG_BLK_DEV_ZONED
-- 
2.25.1

[PATCH v2 06/11] btrfs: zoned: Make sb_zone_number function non power of 2 compatible

[Pankaj Raghav]

Make the calculation in sb_zone_number function to be generic and work
for both power-of-2 and non power-of-2 zone sizes.

The function signature has been modified to take block device and mirror
as input as this function is only invoked from callers that have access
to the block device. This enables to use the generic bdev_zone_no
function provided by the block layer to calculate the zone number.

Even though division is used to calculate the zone index for non
power-of-2 zone sizes, this function will not be used in the fast path as
the sb_zone_location cache is used for the superblock zone location.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 fs/btrfs/zoned.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index e8c7cebb2..5be2ef7bb 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -34,9 +34,6 @@
 #define BTRFS_SB_LOG_FIRST_OFFSET	(512ULL * SZ_1G)
 #define BTRFS_SB_LOG_SECOND_OFFSET	(4096ULL * SZ_1G)
 
-#define BTRFS_SB_LOG_FIRST_SHIFT	const_ilog2(BTRFS_SB_LOG_FIRST_OFFSET)
-#define BTRFS_SB_LOG_SECOND_SHIFT	const_ilog2(BTRFS_SB_LOG_SECOND_OFFSET)
-
 /* Number of superblock log zones */
 #define BTRFS_NR_SB_LOG_ZONES 2
 
@@ -153,15 +150,23 @@ static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones,
 /*
  * Get the first zone number of the superblock mirror
  */
-static inline u32 sb_zone_number(int shift, int mirror)
+static inline u32 sb_zone_number(struct block_device *bdev, int mirror)
 {
 	u64 zone;
 
 	ASSERT(mirror < BTRFS_SUPER_MIRROR_MAX);
 	switch (mirror) {
-	case 0: zone = 0; break;
-	case 1: zone = 1ULL << (BTRFS_SB_LOG_FIRST_SHIFT - shift); break;
-	case 2: zone = 1ULL << (BTRFS_SB_LOG_SECOND_SHIFT - shift); break;
+	case 0:
+		zone = 0;
+		break;
+	case 1:
+		zone = bdev_zone_no(bdev,
+				    BTRFS_SB_LOG_FIRST_OFFSET >> SECTOR_SHIFT);
+		break;
+	case 2:
+		zone = bdev_zone_no(bdev,
+				    BTRFS_SB_LOG_SECOND_OFFSET >> SECTOR_SHIFT);
+		break;
 	}
 
 	ASSERT(zone <= U32_MAX);
@@ -514,7 +519,7 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache)
 	/* Cache the sb zone number */
 	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; ++i) {
 		zone_info->sb_zone_location[i] =
-			sb_zone_number(zone_info->zone_size_shift, i);
+			sb_zone_number(bdev, i);
 	}
 	/* Validate superblock log */
 	nr_zones = BTRFS_NR_SB_LOG_ZONES;
@@ -839,7 +844,7 @@ int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
 	nr_sectors = bdev_nr_sectors(bdev);
 	nr_zones = nr_sectors >> zone_sectors_shift;
 
-	sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
+	sb_zone = sb_zone_number(bdev, mirror);
 	if (sb_zone + 1 >= nr_zones)
 		return -ENOENT;
 
@@ -963,7 +968,7 @@ int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
 	nr_sectors = bdev_nr_sectors(bdev);
 	nr_zones = nr_sectors >> zone_sectors_shift;
 
-	sb_zone = sb_zone_number(zone_sectors_shift + SECTOR_SHIFT, mirror);
+	sb_zone = sb_zone_number(bdev, mirror);
 	if (sb_zone + 1 >= nr_zones)
 		return -ENOENT;
 
-- 
2.25.1

[PATCH v2 07/11] btrfs: zoned: use generic btrfs zone helpers to support npo2 zoned devices

[Pankaj Raghav]

Add helpers to calculate alignment, round up and round down
for zoned devices. These helpers encapsulates the necessary handling for
power_of_2 and non-power_of_2 zone sizes. Optimized calculations are
performed for zone sizes that are power_of_2 with log and shifts.

btrfs_zoned_is_aligned() is added instead of reusing bdev_zone_aligned()
helper due to some use cases in btrfs where zone alignment is checked
before having access to the underlying block device such as in this
function: btrfs_load_block_group_zone_info().

Use the generic btrfs zone helpers to calculate zone index, check zone
alignment, round up and round down operations.

The zone_size_shift field is not needed anymore as generic helpers are
used for calculation.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 fs/btrfs/volumes.c | 24 +++++++++-------
 fs/btrfs/zoned.c   | 72 ++++++++++++++++++++++------------------------
 fs/btrfs/zoned.h   | 43 +++++++++++++++++++++++----
 3 files changed, 85 insertions(+), 54 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 94f851592..3d6b9a25a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1408,7 +1408,7 @@ static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
 		 * allocator, because we anyway use/reserve the first two zones
 		 * for superblock logging.
 		 */
-		return ALIGN(start, device->zone_info->zone_size);
+		return btrfs_zoned_roundup(start, device->zone_info->zone_size);
 	default:
 		BUG();
 	}
@@ -1423,7 +1423,7 @@ static bool dev_extent_hole_check_zoned(struct btrfs_device *device,
 	int ret;
 	bool changed = false;
 
-	ASSERT(IS_ALIGNED(*hole_start, zone_size));
+	ASSERT(btrfs_zoned_is_aligned(*hole_start, zone_size));
 
 	while (*hole_size > 0) {
 		pos = btrfs_find_allocatable_zones(device, *hole_start,
@@ -1560,7 +1560,7 @@ static int find_free_dev_extent_start(struct btrfs_device *device,
 	search_start = dev_extent_search_start(device, search_start);
 
 	WARN_ON(device->zone_info &&
-		!IS_ALIGNED(num_bytes, device->zone_info->zone_size));
+		!btrfs_zoned_is_aligned(num_bytes, device->zone_info->zone_size));
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -5111,8 +5111,8 @@ static void init_alloc_chunk_ctl_policy_zoned(
 
 	ctl->max_stripe_size = zone_size;
 	if (type & BTRFS_BLOCK_GROUP_DATA) {
-		ctl->max_chunk_size = round_down(BTRFS_MAX_DATA_CHUNK_SIZE,
-						 zone_size);
+		ctl->max_chunk_size = btrfs_zoned_rounddown(
+			BTRFS_MAX_DATA_CHUNK_SIZE, zone_size);
 	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
 		ctl->max_chunk_size = ctl->max_stripe_size;
 	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
@@ -5124,9 +5124,10 @@ static void init_alloc_chunk_ctl_policy_zoned(
 	}
 
 	/* We don't want a chunk larger than 10% of writable space */
-	limit = max(round_down(div_factor(fs_devices->total_rw_bytes, 1),
-			       zone_size),
-		    min_chunk_size);
+	limit = max(
+		btrfs_zoned_rounddown(div_factor(fs_devices->total_rw_bytes, 1),
+				      zone_size),
+		min_chunk_size);
 	ctl->max_chunk_size = min(limit, ctl->max_chunk_size);
 	ctl->dev_extent_min = zone_size * ctl->dev_stripes;
 }
@@ -6729,7 +6730,8 @@ static void submit_stripe_bio(struct btrfs_io_context *bioc,
 	 */
 	if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
 		if (btrfs_dev_is_sequential(dev, physical)) {
-			u64 zone_start = round_down(physical, fs_info->zone_size);
+			u64 zone_start = btrfs_zoned_rounddown(physical,
+							fs_info->zone_size);
 
 			bio->bi_iter.bi_sector = zone_start >> SECTOR_SHIFT;
 		} else {
@@ -8051,8 +8053,8 @@ static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
 	if (dev->zone_info) {
 		u64 zone_size = dev->zone_info->zone_size;
 
-		if (!IS_ALIGNED(physical_offset, zone_size) ||
-		    !IS_ALIGNED(physical_len, zone_size)) {
+		if (!btrfs_zoned_is_aligned(physical_offset, zone_size) ||
+		    !btrfs_zoned_is_aligned(physical_len, zone_size)) {
 			btrfs_err(fs_info,
 "zoned: dev extent devid %llu physical offset %llu len %llu is not aligned to device zone",
 				  devid, physical_offset, physical_len);
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 5be2ef7bb..3023c871e 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -177,13 +177,13 @@ static inline u32 sb_zone_number(struct block_device *bdev, int mirror)
 static inline sector_t zone_start_sector(u32 zone_number,
 					 struct block_device *bdev)
 {
-	return (sector_t)zone_number << ilog2(bdev_zone_sectors(bdev));
+	return zone_number * bdev_zone_sectors(bdev);
 }
 
 static inline u64 zone_start_physical(u32 zone_number,
 				      struct btrfs_zoned_device_info *zone_info)
 {
-	return (u64)zone_number << zone_info->zone_size_shift;
+	return zone_number * zone_info->zone_size;
 }
 
 /*
@@ -236,8 +236,8 @@ static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
 	if (zinfo->zone_cache) {
 		unsigned int i;
 
-		ASSERT(IS_ALIGNED(pos, zinfo->zone_size));
-		zno = pos >> zinfo->zone_size_shift;
+		ASSERT(btrfs_zoned_is_aligned(pos, zinfo->zone_size));
+		zno = bdev_zone_no(device->bdev, pos >> SECTOR_SHIFT);
 		/*
 		 * We cannot report zones beyond the zone end. So, it is OK to
 		 * cap *nr_zones to at the end.
@@ -409,9 +409,8 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache)
 	}
 
 	nr_sectors = bdev_nr_sectors(bdev);
-	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
-	zone_info->nr_zones = nr_sectors >> ilog2(zone_sectors);
-	if (!IS_ALIGNED(nr_sectors, zone_sectors))
+	zone_info->nr_zones = bdev_zone_no(bdev, nr_sectors);
+	if (!btrfs_zoned_is_aligned(nr_sectors, zone_sectors))
 		zone_info->nr_zones++;
 
 	max_active_zones = bdev_max_active_zones(bdev);
@@ -823,10 +822,8 @@ int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
 			       u64 *bytenr_ret)
 {
 	struct blk_zone zones[BTRFS_NR_SB_LOG_ZONES];
-	sector_t zone_sectors;
 	u32 sb_zone;
 	int ret;
-	u8 zone_sectors_shift;
 	sector_t nr_sectors;
 	u32 nr_zones;
 
@@ -837,12 +834,10 @@ int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
 
 	ASSERT(rw == READ || rw == WRITE);
 
-	zone_sectors = bdev_zone_sectors(bdev);
-	if (!is_power_of_2(zone_sectors))
+	if (!is_power_of_2(bdev_zone_sectors(bdev)))
 		return -EINVAL;
-	zone_sectors_shift = ilog2(zone_sectors);
 	nr_sectors = bdev_nr_sectors(bdev);
-	nr_zones = nr_sectors >> zone_sectors_shift;
+	nr_zones = bdev_zone_no(bdev, nr_sectors);
 
 	sb_zone = sb_zone_number(bdev, mirror);
 	if (sb_zone + 1 >= nr_zones)
@@ -959,14 +954,12 @@ int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
 {
 	sector_t zone_sectors;
 	sector_t nr_sectors;
-	u8 zone_sectors_shift;
 	u32 sb_zone;
 	u32 nr_zones;
 
 	zone_sectors = bdev_zone_sectors(bdev);
-	zone_sectors_shift = ilog2(zone_sectors);
 	nr_sectors = bdev_nr_sectors(bdev);
-	nr_zones = nr_sectors >> zone_sectors_shift;
+	nr_zones = bdev_zone_no(bdev, nr_sectors);
 
 	sb_zone = sb_zone_number(bdev, mirror);
 	if (sb_zone + 1 >= nr_zones)
@@ -992,18 +985,17 @@ u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
 				 u64 hole_end, u64 num_bytes)
 {
 	struct btrfs_zoned_device_info *zinfo = device->zone_info;
-	const u8 shift = zinfo->zone_size_shift;
-	u64 nzones = num_bytes >> shift;
+	u64 nzones = bdev_zone_no(device->bdev, num_bytes >> SECTOR_SHIFT);
 	u64 pos = hole_start;
 	u64 begin, end;
 	bool have_sb;
 	int i;
 
-	ASSERT(IS_ALIGNED(hole_start, zinfo->zone_size));
-	ASSERT(IS_ALIGNED(num_bytes, zinfo->zone_size));
+	ASSERT(btrfs_zoned_is_aligned(hole_start, zinfo->zone_size));
+	ASSERT(btrfs_zoned_is_aligned(num_bytes, zinfo->zone_size));
 
 	while (pos < hole_end) {
-		begin = pos >> shift;
+		begin = bdev_zone_no(device->bdev, pos >> SECTOR_SHIFT);
 		end = begin + nzones;
 
 		if (end > zinfo->nr_zones)
@@ -1035,8 +1027,9 @@ u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
 			if (!(pos + num_bytes <= sb_pos ||
 			      sb_pos + BTRFS_SUPER_INFO_SIZE <= pos)) {
 				have_sb = true;
-				pos = ALIGN(sb_pos + BTRFS_SUPER_INFO_SIZE,
-					    zinfo->zone_size);
+				pos = btrfs_zoned_roundup(
+					sb_pos + BTRFS_SUPER_INFO_SIZE,
+					zinfo->zone_size);
 				break;
 			}
 		}
@@ -1050,7 +1043,7 @@ u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
 static bool btrfs_dev_set_active_zone(struct btrfs_device *device, u64 pos)
 {
 	struct btrfs_zoned_device_info *zone_info = device->zone_info;
-	unsigned int zno = (pos >> zone_info->zone_size_shift);
+	unsigned int zno = bdev_zone_no(device->bdev, pos >> SECTOR_SHIFT);
 
 	/* We can use any number of zones */
 	if (zone_info->max_active_zones == 0)
@@ -1072,7 +1065,7 @@ static bool btrfs_dev_set_active_zone(struct btrfs_device *device, u64 pos)
 static void btrfs_dev_clear_active_zone(struct btrfs_device *device, u64 pos)
 {
 	struct btrfs_zoned_device_info *zone_info = device->zone_info;
-	unsigned int zno = (pos >> zone_info->zone_size_shift);
+	unsigned int zno = bdev_zone_no(device->bdev, pos >> SECTOR_SHIFT);
 
 	/* We can use any number of zones */
 	if (zone_info->max_active_zones == 0)
@@ -1108,14 +1101,14 @@ int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
 int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
 {
 	struct btrfs_zoned_device_info *zinfo = device->zone_info;
-	const u8 shift = zinfo->zone_size_shift;
-	unsigned long begin = start >> shift;
-	unsigned long end = (start + size) >> shift;
+	unsigned long begin = bdev_zone_no(device->bdev, start >> SECTOR_SHIFT);
+	unsigned long end =
+		bdev_zone_no(device->bdev, (start + size) >> SECTOR_SHIFT);
 	u64 pos;
 	int ret;
 
-	ASSERT(IS_ALIGNED(start, zinfo->zone_size));
-	ASSERT(IS_ALIGNED(size, zinfo->zone_size));
+	ASSERT(btrfs_zoned_is_aligned(start, zinfo->zone_size));
+	ASSERT(btrfs_zoned_is_aligned(size, zinfo->zone_size));
 
 	if (end > zinfo->nr_zones)
 		return -ERANGE;
@@ -1139,8 +1132,9 @@ int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
 		/* Free regions should be empty */
 		btrfs_warn_in_rcu(
 			device->fs_info,
-		"zoned: resetting device %s (devid %llu) zone %llu for allocation",
-			rcu_str_deref(device->name), device->devid, pos >> shift);
+			"zoned: resetting device %s (devid %llu) zone %u for allocation",
+			rcu_str_deref(device->name), device->devid,
+			bdev_zone_no(device->bdev, pos >> SECTOR_SHIFT));
 		WARN_ON_ONCE(1);
 
 		ret = btrfs_reset_device_zone(device, pos, zinfo->zone_size,
@@ -1237,7 +1231,7 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
 		return 0;
 
 	/* Sanity check */
-	if (!IS_ALIGNED(length, fs_info->zone_size)) {
+	if (!btrfs_zoned_is_aligned(length, fs_info->zone_size)) {
 		btrfs_err(fs_info,
 		"zoned: block group %llu len %llu unaligned to zone size %llu",
 			  logical, length, fs_info->zone_size);
@@ -1325,7 +1319,7 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
 		 * The group is mapped to a sequential zone. Get the zone write
 		 * pointer to determine the allocation offset within the zone.
 		 */
-		WARN_ON(!IS_ALIGNED(physical[i], fs_info->zone_size));
+		WARN_ON(!btrfs_zoned_is_aligned(physical[i], fs_info->zone_size));
 		nofs_flag = memalloc_nofs_save();
 		ret = btrfs_get_dev_zone(device, physical[i], &zone);
 		memalloc_nofs_restore(nofs_flag);
@@ -1351,10 +1345,12 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
 		switch (zone.cond) {
 		case BLK_ZONE_COND_OFFLINE:
 		case BLK_ZONE_COND_READONLY:
-			btrfs_err(fs_info,
-		"zoned: offline/readonly zone %llu on device %s (devid %llu)",
-				  physical[i] >> device->zone_info->zone_size_shift,
-				  rcu_str_deref(device->name), device->devid);
+			btrfs_err(
+				fs_info,
+				"zoned: offline/readonly zone %u on device %s (devid %llu)",
+				bdev_zone_no(device->bdev,
+					     physical[i] >> SECTOR_SHIFT),
+				rcu_str_deref(device->name), device->devid);
 			alloc_offsets[i] = WP_MISSING_DEV;
 			break;
 		case BLK_ZONE_COND_EMPTY:
diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
index 694ab6d1e..b94ce4d1f 100644
--- a/fs/btrfs/zoned.h
+++ b/fs/btrfs/zoned.h
@@ -9,6 +9,7 @@
 #include "disk-io.h"
 #include "block-group.h"
 #include "btrfs_inode.h"
+#include "misc.h"
 
 #define BTRFS_DEFAULT_RECLAIM_THRESH           			(75)
 
@@ -18,7 +19,6 @@ struct btrfs_zoned_device_info {
 	 * zoned block device.
 	 */
 	u64 zone_size;
-	u8  zone_size_shift;
 	u32 nr_zones;
 	unsigned int max_active_zones;
 	atomic_t active_zones_left;
@@ -30,6 +30,36 @@ struct btrfs_zoned_device_info {
 	u32 sb_zone_location[BTRFS_SUPER_MIRROR_MAX];
 };
 
+static inline bool btrfs_zoned_is_aligned(u64 pos, u64 zone_size)
+{
+	u64 remainder = 0;
+
+	if (is_power_of_two_u64(zone_size))
+		return IS_ALIGNED(pos, zone_size);
+
+	div64_u64_rem(pos, zone_size, &remainder);
+	return remainder == 0;
+}
+
+static inline u64 btrfs_zoned_roundup(u64 pos, u64 zone_size)
+{
+	if (is_power_of_two_u64(zone_size))
+		return ALIGN(pos, zone_size);
+
+	return div64_u64(pos + zone_size - 1, zone_size) * zone_size;
+}
+
+static inline u64 btrfs_zoned_rounddown(u64 pos, u64 zone_size)
+{
+	u64 remainder = 0;
+	if (is_power_of_two_u64(zone_size))
+		return round_down(pos, zone_size);
+
+	div64_u64_rem(pos, zone_size, &remainder);
+	pos -= remainder;
+	return pos;
+}
+
 #ifdef CONFIG_BLK_DEV_ZONED
 int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
 		       struct blk_zone *zone);
@@ -253,7 +283,8 @@ static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
 	if (!zone_info)
 		return false;
 
-	return test_bit(pos >> zone_info->zone_size_shift, zone_info->seq_zones);
+	return test_bit(bdev_zone_no(device->bdev, pos >> SECTOR_SHIFT),
+			zone_info->seq_zones);
 }
 
 static inline bool btrfs_dev_is_empty_zone(struct btrfs_device *device, u64 pos)
@@ -263,7 +294,8 @@ static inline bool btrfs_dev_is_empty_zone(struct btrfs_device *device, u64 pos)
 	if (!zone_info)
 		return true;
 
-	return test_bit(pos >> zone_info->zone_size_shift, zone_info->empty_zones);
+	return test_bit(bdev_zone_no(device->bdev, pos >> SECTOR_SHIFT),
+			zone_info->empty_zones);
 }
 
 static inline void btrfs_dev_set_empty_zone_bit(struct btrfs_device *device,
@@ -275,7 +307,7 @@ static inline void btrfs_dev_set_empty_zone_bit(struct btrfs_device *device,
 	if (!zone_info)
 		return;
 
-	zno = pos >> zone_info->zone_size_shift;
+	zno = bdev_zone_no(device->bdev, pos >> SECTOR_SHIFT);
 	if (set)
 		set_bit(zno, zone_info->empty_zones);
 	else
@@ -329,7 +361,8 @@ static inline bool btrfs_can_zone_reset(struct btrfs_device *device,
 		return false;
 
 	zone_size = device->zone_info->zone_size;
-	if (!IS_ALIGNED(physical, zone_size) || !IS_ALIGNED(length, zone_size))
+	if (!btrfs_zoned_is_aligned(physical, zone_size) ||
+	    !btrfs_zoned_is_aligned(length, zone_size))
 		return false;
 
 	return true;
-- 
2.25.1

[PATCH v2 08/11] btrfs: zoned: relax the alignment constraint for zoned devices

[Pankaj Raghav]

Checks were in place to return error when a non power-of-2 zoned devices
is detected. Remove those checks as non power-of-2 zoned devices are
now supported.

Relax the zone size constraint to align with a sane default of 1MB.
This 1M default has been chosen as the minimum alignment requirement
for zone sizes to make sure zones align with sectorsize in different
architectures.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 fs/btrfs/zoned.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 3023c871e..a6b15fbe1 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -54,6 +54,13 @@
  */
 #define BTRFS_MAX_ZONE_SIZE		SZ_8G
 
+/*
+ * A minimum alignment of 1MB is chosen for zoned devices as their zone sizes
+ * can be non power of 2. This is to make sure the zones correctly align to the
+ * sectorsize.
+ */
+#define BTRFS_ZONED_MIN_ALIGN_SECTORS       ((u64)SZ_1M >> SECTOR_SHIFT)
+
 #define SUPER_INFO_SECTORS	((u64)BTRFS_SUPER_INFO_SIZE >> SECTOR_SHIFT)
 
 static inline bool sb_zone_is_full(const struct blk_zone *zone)
@@ -394,8 +401,8 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache)
 		zone_sectors = bdev_zone_sectors(bdev);
 	}
 
-	/* Check if it's power of 2 (see is_power_of_2) */
-	ASSERT(zone_sectors != 0 && (zone_sectors & (zone_sectors - 1)) == 0);
+	ASSERT(zone_sectors != 0 &&
+	       IS_ALIGNED(zone_sectors, BTRFS_ZONED_MIN_ALIGN_SECTORS));
 	zone_info->zone_size = zone_sectors << SECTOR_SHIFT;
 
 	/* We reject devices with a zone size larger than 8GB */
@@ -834,9 +841,11 @@ int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
 
 	ASSERT(rw == READ || rw == WRITE);
 
-	if (!is_power_of_2(bdev_zone_sectors(bdev)))
-		return -EINVAL;
 	nr_sectors = bdev_nr_sectors(bdev);
+
+	if (!IS_ALIGNED(nr_sectors, BTRFS_ZONED_MIN_ALIGN_SECTORS))
+		return -EINVAL;
+
 	nr_zones = bdev_zone_no(bdev, nr_sectors);
 
 	sb_zone = sb_zone_number(bdev, mirror);
-- 
2.25.1

[PATCH v2 09/11] zonefs: allow non power of 2 zoned devices

[Pankaj Raghav]

The zone size shift variable is useful only if the zone sizes are known
to be power of 2. Remove that variable and use generic helpers from
block layer to calculate zone index in zonefs.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 fs/zonefs/super.c  | 6 ++----
 fs/zonefs/zonefs.h | 1 -
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index 978a35c45..50a1e000c 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -451,10 +451,9 @@ static void __zonefs_io_error(struct inode *inode, bool write)
 {
 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 	struct super_block *sb = inode->i_sb;
-	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
 	unsigned int noio_flag;
 	unsigned int nr_zones =
-		zi->i_zone_size >> (sbi->s_zone_sectors_shift + SECTOR_SHIFT);
+		bdev_zone_no(sb->s_bdev, zi->i_zone_size >> SECTOR_SHIFT);
 	struct zonefs_ioerr_data err = {
 		.inode = inode,
 		.write = write,
@@ -1375,7 +1374,7 @@ static int zonefs_init_file_inode(struct inode *inode, struct blk_zone *zone,
 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 	int ret;
 
-	inode->i_ino = zone->start >> sbi->s_zone_sectors_shift;
+	inode->i_ino = bdev_zone_no(sb->s_bdev, zone->start);
 	inode->i_mode = S_IFREG | sbi->s_perm;
 
 	zi->i_ztype = type;
@@ -1752,7 +1751,6 @@ static int zonefs_fill_super(struct super_block *sb, void *data, int silent)
 	 * interface constraints.
 	 */
 	sb_set_blocksize(sb, bdev_zone_write_granularity(sb->s_bdev));
-	sbi->s_zone_sectors_shift = ilog2(bdev_zone_sectors(sb->s_bdev));
 	sbi->s_uid = GLOBAL_ROOT_UID;
 	sbi->s_gid = GLOBAL_ROOT_GID;
 	sbi->s_perm = 0640;
diff --git a/fs/zonefs/zonefs.h b/fs/zonefs/zonefs.h
index 4b3de66c3..39895195c 100644
--- a/fs/zonefs/zonefs.h
+++ b/fs/zonefs/zonefs.h
@@ -177,7 +177,6 @@ struct zonefs_sb_info {
 	kgid_t			s_gid;
 	umode_t			s_perm;
 	uuid_t			s_uuid;
-	unsigned int		s_zone_sectors_shift;
 
 	unsigned int		s_nr_files[ZONEFS_ZTYPE_MAX];
 
-- 
2.25.1

[PATCH v2 10/11] null_blk: allow non power of 2 zoned devices

[Pankaj Raghav]

Convert the power of 2 based calculation with zone size to be generic in
null_zone_no with optimization for power of 2 based zone sizes.

The nr_zones calculation in null_init_zoned_dev has been replaced with a
division without special handling for power of 2 based zone sizes as
this function is called only during the initialization and will not
invoked in the hot path.

Performance Measurement:

Device:
zone size = 128M, blocksize=4k

FIO cmd:

fio --name=zbc --filename=/dev/nullb0 --direct=1 --zonemode=zbd  --size=23G
--io_size=<iosize> --ioengine=io_uring --iodepth=<iod> --rw=<mode> --bs=4k
--loops=4

The following results are an average of 4 runs on AMD Ryzen 5 5600X with
32GB of RAM:

Sequential Write:

x-----------------x---------------------------------x---------------------------------x
|     IOdepth     |            8                    |            16                   |
x-----------------x---------------------------------x---------------------------------x
|                 |  KIOPS   |BW(MiB/s) | Lat(usec) |  KIOPS   |BW(MiB/s) | Lat(usec) |
x-----------------x---------------------------------x---------------------------------x
| Without patch   |  578     |  2257    |   12.80   |  576     |  2248    |   25.78   |
x-----------------x---------------------------------x---------------------------------x
|  With patch     |  581     |  2268    |   12.74   |  576     |  2248    |   25.85   |
x-----------------x---------------------------------x---------------------------------x

Sequential read:

x-----------------x---------------------------------x---------------------------------x
| IOdepth         |            8                    |            16                   |
x-----------------x---------------------------------x---------------------------------x
|                 |  KIOPS   |BW(MiB/s) | Lat(usec) |  KIOPS   |BW(MiB/s) | Lat(usec) |
x-----------------x---------------------------------x---------------------------------x
| Without patch   |  667     |  2605    |   11.79   |  675     |  2637    |   23.49   |
x-----------------x---------------------------------x---------------------------------x
|  With patch     |  667     |  2605    |   11.79   |  675     |  2638    |   23.48   |
x-----------------x---------------------------------x---------------------------------x

Random read:

x-----------------x---------------------------------x---------------------------------x
| IOdepth         |            8                    |            16                   |
x-----------------x---------------------------------x---------------------------------x
|                 |  KIOPS   |BW(MiB/s) | Lat(usec) |  KIOPS   |BW(MiB/s) | Lat(usec) |
x-----------------x---------------------------------x---------------------------------x
| Without patch   |  522     |  2038    |   15.05   |  514     |  2006    |   30.87   |
x-----------------x---------------------------------x---------------------------------x
|  With patch     |  522     |  2039    |   15.04   |  523     |  2042    |   30.33   |
x-----------------x---------------------------------x---------------------------------x

Minor variations are noticed in Sequential write with io depth 8 and
in random read with io depth 16. But overall no noticeable differences
were noticed

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed by: Adam Manzanares <a.manzanares@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 drivers/block/null_blk/main.c  |  5 ++---
 drivers/block/null_blk/zoned.c | 14 +++++++-------
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 5cb4c92cd..ed9a58201 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1929,9 +1929,8 @@ static int null_validate_conf(struct nullb_device *dev)
 	if (dev->queue_mode == NULL_Q_BIO)
 		dev->mbps = 0;
 
-	if (dev->zoned &&
-	    (!dev->zone_size || !is_power_of_2(dev->zone_size))) {
-		pr_err("zone_size must be power-of-two\n");
+	if (dev->zoned && !dev->zone_size) {
+		pr_err("zone_size must not be zero\n");
 		return -EINVAL;
 	}
 
diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c
index dae54dd1a..00c34e65e 100644
--- a/drivers/block/null_blk/zoned.c
+++ b/drivers/block/null_blk/zoned.c
@@ -13,7 +13,10 @@ static inline sector_t mb_to_sects(unsigned long mb)
 
 static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
 {
-	return sect >> ilog2(dev->zone_size_sects);
+	if (is_power_of_2(dev->zone_size_sects))
+		return sect >> ilog2(dev->zone_size_sects);
+
+	return div64_u64(sect, dev->zone_size_sects);
 }
 
 static inline void null_lock_zone_res(struct nullb_device *dev)
@@ -62,10 +65,6 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
 	sector_t sector = 0;
 	unsigned int i;
 
-	if (!is_power_of_2(dev->zone_size)) {
-		pr_err("zone_size must be power-of-two\n");
-		return -EINVAL;
-	}
 	if (dev->zone_size > dev->size) {
 		pr_err("Zone size larger than device capacity\n");
 		return -EINVAL;
@@ -83,8 +82,9 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
 	zone_capacity_sects = mb_to_sects(dev->zone_capacity);
 	dev_capacity_sects = mb_to_sects(dev->size);
 	dev->zone_size_sects = mb_to_sects(dev->zone_size);
-	dev->nr_zones = round_up(dev_capacity_sects, dev->zone_size_sects)
-		>> ilog2(dev->zone_size_sects);
+	dev->nr_zones =
+		div64_u64(roundup(dev_capacity_sects, dev->zone_size_sects),
+			  dev->zone_size_sects);
 
 	dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct nullb_zone),
 				    GFP_KERNEL | __GFP_ZERO);
-- 
2.25.1

[PATCH v2 11/11] dm-zoned: ensure only power of 2 zone sizes are allowed

[Pankaj Raghav]

From: Luis Chamberlain <mcgrof@kernel.org>

Today dm-zoned relies on the assumption that you have a zone size
with a power of 2. Even though the block layer today enforces this
requirement, these devices do exist and so provide a stop-gap measure
to ensure these devices cannot be used by mistake

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 drivers/md/dm-zone.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/md/dm-zone.c b/drivers/md/dm-zone.c
index 3e7b1fe15..27dc4ddf2 100644
--- a/drivers/md/dm-zone.c
+++ b/drivers/md/dm-zone.c
@@ -231,6 +231,18 @@ static int dm_revalidate_zones(struct mapped_device *md, struct dm_table *t)
 	struct request_queue *q = md->queue;
 	unsigned int noio_flag;
 	int ret;
+	struct block_device *bdev = md->disk->part0;
+	sector_t zone_sectors;
+	char bname[BDEVNAME_SIZE];
+
+	zone_sectors = bdev_zone_sectors(bdev);
+
+	if (!is_power_of_2(zone_sectors)) {
+		DMWARN("%s: %s only power of two zone size supported\n",
+		       dm_device_name(md),
+		       bdevname(bdev, bname));
+		return 1;
+	}
 
 	/*
 	 * Check if something changed. If yes, cleanup the current resources
-- 
2.25.1