[v6,02/28] btrfs: Get zone information of zoned block devices
diff mbox series

Message ID 20191213040915.3502922-3-naohiro.aota@wdc.com
State New
Headers show
Series
  • btrfs: zoned block device support
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Commit Message

Naohiro Aota Dec. 13, 2019, 4:08 a.m. UTC
If a zoned block device is found, get its zone information (number of zones
and zone size) using the new helper function btrfs_get_dev_zone_info().  To
avoid costly run-time zone report commands to test the device zones type
during block allocation, attach the seq_zones bitmap to the device
structure to indicate if a zone is sequential or accept random writes. Also
it attaches the empty_zones bitmap to indicate if a zone is empty or not.

This patch also introduces the helper function btrfs_dev_is_sequential() to
test if the zone storing a block is a sequential write required zone and
btrfs_dev_is_empty_zone() to test if the zone is a empty zone.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/Makefile  |   1 +
 fs/btrfs/hmzoned.c | 168 +++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/hmzoned.h |  92 +++++++++++++++++++++++++
 fs/btrfs/volumes.c |  18 ++++-
 fs/btrfs/volumes.h |   4 ++
 5 files changed, 281 insertions(+), 2 deletions(-)
 create mode 100644 fs/btrfs/hmzoned.c
 create mode 100644 fs/btrfs/hmzoned.h

Comments

Josef Bacik Dec. 13, 2019, 4:18 p.m. UTC | #1
On 12/12/19 11:08 PM, Naohiro Aota wrote:
> If a zoned block device is found, get its zone information (number of zones
> and zone size) using the new helper function btrfs_get_dev_zone_info().  To
> avoid costly run-time zone report commands to test the device zones type
> during block allocation, attach the seq_zones bitmap to the device
> structure to indicate if a zone is sequential or accept random writes. Also
> it attaches the empty_zones bitmap to indicate if a zone is empty or not.
> 
> This patch also introduces the helper function btrfs_dev_is_sequential() to
> test if the zone storing a block is a sequential write required zone and
> btrfs_dev_is_empty_zone() to test if the zone is a empty zone.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>   fs/btrfs/Makefile  |   1 +
>   fs/btrfs/hmzoned.c | 168 +++++++++++++++++++++++++++++++++++++++++++++
>   fs/btrfs/hmzoned.h |  92 +++++++++++++++++++++++++
>   fs/btrfs/volumes.c |  18 ++++-
>   fs/btrfs/volumes.h |   4 ++
>   5 files changed, 281 insertions(+), 2 deletions(-)
>   create mode 100644 fs/btrfs/hmzoned.c
>   create mode 100644 fs/btrfs/hmzoned.h
> 
> diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
> index 82200dbca5ac..64aaeed397a4 100644
> --- a/fs/btrfs/Makefile
> +++ b/fs/btrfs/Makefile
> @@ -16,6 +16,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
>   btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
>   btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
>   btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o
> +btrfs-$(CONFIG_BLK_DEV_ZONED) += hmzoned.o
>   
>   btrfs-$(CONFIG_BTRFS_FS_RUN_SANITY_TESTS) += tests/free-space-tests.o \
>   	tests/extent-buffer-tests.o tests/btrfs-tests.o \
> diff --git a/fs/btrfs/hmzoned.c b/fs/btrfs/hmzoned.c
> new file mode 100644
> index 000000000000..6a13763d2916
> --- /dev/null
> +++ b/fs/btrfs/hmzoned.c
> @@ -0,0 +1,168 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 Western Digital Corporation or its affiliates.
> + * Authors:
> + *	Naohiro Aota	<naohiro.aota@wdc.com>
> + *	Damien Le Moal	<damien.lemoal@wdc.com>
> + */
> +
> +#include <linux/slab.h>
> +#include <linux/blkdev.h>
> +#include "ctree.h"
> +#include "volumes.h"
> +#include "hmzoned.h"
> +#include "rcu-string.h"
> +
> +/* Maximum number of zones to report per blkdev_report_zones() call */
> +#define BTRFS_REPORT_NR_ZONES   4096
> +
> +static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
> +			       struct blk_zone *zones, unsigned int *nr_zones)
> +{
> +	int ret;
> +
> +	ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, zones,
> +				  nr_zones);
> +	if (ret != 0) {
> +		btrfs_err_in_rcu(device->fs_info,
> +				 "get zone at %llu on %s failed %d", pos,
> +				 rcu_str_deref(device->name), ret);
> +		return ret;
> +	}
> +	if (!*nr_zones)
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +int btrfs_get_dev_zone_info(struct btrfs_device *device)
> +{
> +	struct btrfs_zoned_device_info *zone_info = NULL;
> +	struct block_device *bdev = device->bdev;
> +	sector_t nr_sectors = bdev->bd_part->nr_sects;
> +	sector_t sector = 0;
> +	struct blk_zone *zones = NULL;
> +	unsigned int i, nreported = 0, nr_zones;
> +	unsigned int zone_sectors;
> +	int ret;
> +	char devstr[sizeof(device->fs_info->sb->s_id) +
> +		    sizeof(" (device )") - 1];
> +
> +	if (!bdev_is_zoned(bdev))
> +		return 0;
> +
> +	zone_info = kzalloc(sizeof(*zone_info), GFP_KERNEL);
> +	if (!zone_info)
> +		return -ENOMEM;
> +
> +	zone_sectors = bdev_zone_sectors(bdev);
> +	ASSERT(is_power_of_2(zone_sectors));
> +	zone_info->zone_size = (u64)zone_sectors << SECTOR_SHIFT;
> +	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
> +	zone_info->nr_zones = nr_sectors >> ilog2(bdev_zone_sectors(bdev));
> +	if (!IS_ALIGNED(nr_sectors, zone_sectors))
> +		zone_info->nr_zones++;
> +
> +	zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
> +	if (!zone_info->seq_zones) {
> +		ret = -ENOMEM;
> +		goto free_zone_info;
> +	}
> +
> +	zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
> +	if (!zone_info->empty_zones) {
> +		ret = -ENOMEM;
> +		goto free_seq_zones;
> +	}
> +
> +	zones = kcalloc(BTRFS_REPORT_NR_ZONES,
> +			sizeof(struct blk_zone), GFP_KERNEL);
> +	if (!zones) {
> +		ret = -ENOMEM;
> +		goto free_empty_zones;
> +	}
> +
> +	/* Get zones type */
> +	while (sector < nr_sectors) {
> +		nr_zones = BTRFS_REPORT_NR_ZONES;
> +		ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT, zones,
> +					  &nr_zones);
> +		if (ret)
> +			goto free_zones;
> +
> +		for (i = 0; i < nr_zones; i++) {
> +			if (zones[i].type == BLK_ZONE_TYPE_SEQWRITE_REQ)
> +				set_bit(nreported, zone_info->seq_zones);
> +			if (zones[i].cond == BLK_ZONE_COND_EMPTY)
> +				set_bit(nreported, zone_info->empty_zones);
> +			nreported++;
> +		}
> +		sector = zones[nr_zones - 1].start + zones[nr_zones - 1].len;
> +	}
> +
> +	if (nreported != zone_info->nr_zones) {
> +		btrfs_err_in_rcu(device->fs_info,
> +				 "inconsistent number of zones on %s (%u / %u)",
> +				 rcu_str_deref(device->name), nreported,
> +				 zone_info->nr_zones);
> +		ret = -EIO;
> +		goto free_zones;
> +	}
> +
> +	kfree(zones);
> +
> +	device->zone_info = zone_info;
> +
> +	devstr[0] = 0;
> +	if (device->fs_info)
> +		snprintf(devstr, sizeof(devstr), " (device %s)",
> +			 device->fs_info->sb->s_id);
> +
> +	rcu_read_lock();
> +	pr_info(
> +"BTRFS info%s: host-%s zoned block device %s, %u zones of %llu sectors",
> +		devstr,
> +		bdev_zoned_model(bdev) == BLK_ZONED_HM ? "managed" : "aware",
> +		rcu_str_deref(device->name), zone_info->nr_zones,
> +		zone_info->zone_size >> SECTOR_SHIFT);
> +	rcu_read_unlock();
> +
> +	return 0;
> +
> +free_zones:
> +	kfree(zones);
> +free_empty_zones:
> +	bitmap_free(zone_info->empty_zones);
> +free_seq_zones:
> +	bitmap_free(zone_info->seq_zones);
> +free_zone_info:

bitmap_free is just a kfree which handles NULL pointers properly, so you only 
need one goto here for cleaning up the zone_info.  Once that's fixed you can add

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Josef
Naohiro Aota Dec. 18, 2019, 2:29 a.m. UTC | #2
On Fri, Dec 13, 2019 at 11:18:53AM -0500, Josef Bacik wrote:
>On 12/12/19 11:08 PM, Naohiro Aota wrote:
>>If a zoned block device is found, get its zone information (number of zones
>>and zone size) using the new helper function btrfs_get_dev_zone_info().  To
>>avoid costly run-time zone report commands to test the device zones type
>>during block allocation, attach the seq_zones bitmap to the device
>>structure to indicate if a zone is sequential or accept random writes. Also
>>it attaches the empty_zones bitmap to indicate if a zone is empty or not.
>>
>>This patch also introduces the helper function btrfs_dev_is_sequential() to
>>test if the zone storing a block is a sequential write required zone and
>>btrfs_dev_is_empty_zone() to test if the zone is a empty zone.
>>
>>Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
>>Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
>>---
>>  fs/btrfs/Makefile  |   1 +
>>  fs/btrfs/hmzoned.c | 168 +++++++++++++++++++++++++++++++++++++++++++++
>>  fs/btrfs/hmzoned.h |  92 +++++++++++++++++++++++++
>>  fs/btrfs/volumes.c |  18 ++++-
>>  fs/btrfs/volumes.h |   4 ++
>>  5 files changed, 281 insertions(+), 2 deletions(-)
>>  create mode 100644 fs/btrfs/hmzoned.c
>>  create mode 100644 fs/btrfs/hmzoned.h
>>
>>diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
>>index 82200dbca5ac..64aaeed397a4 100644
>>--- a/fs/btrfs/Makefile
>>+++ b/fs/btrfs/Makefile
>>@@ -16,6 +16,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
>>  btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
>>  btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
>>  btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o
>>+btrfs-$(CONFIG_BLK_DEV_ZONED) += hmzoned.o
>>  btrfs-$(CONFIG_BTRFS_FS_RUN_SANITY_TESTS) += tests/free-space-tests.o \
>>  	tests/extent-buffer-tests.o tests/btrfs-tests.o \
>>diff --git a/fs/btrfs/hmzoned.c b/fs/btrfs/hmzoned.c
>>new file mode 100644
>>index 000000000000..6a13763d2916
>>--- /dev/null
>>+++ b/fs/btrfs/hmzoned.c
>>@@ -0,0 +1,168 @@
>>+// SPDX-License-Identifier: GPL-2.0
>>+/*
>>+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
>>+ * Authors:
>>+ *	Naohiro Aota	<naohiro.aota@wdc.com>
>>+ *	Damien Le Moal	<damien.lemoal@wdc.com>
>>+ */
>>+
>>+#include <linux/slab.h>
>>+#include <linux/blkdev.h>
>>+#include "ctree.h"
>>+#include "volumes.h"
>>+#include "hmzoned.h"
>>+#include "rcu-string.h"
>>+
>>+/* Maximum number of zones to report per blkdev_report_zones() call */
>>+#define BTRFS_REPORT_NR_ZONES   4096
>>+
>>+static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
>>+			       struct blk_zone *zones, unsigned int *nr_zones)
>>+{
>>+	int ret;
>>+
>>+	ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, zones,
>>+				  nr_zones);
>>+	if (ret != 0) {
>>+		btrfs_err_in_rcu(device->fs_info,
>>+				 "get zone at %llu on %s failed %d", pos,
>>+				 rcu_str_deref(device->name), ret);
>>+		return ret;
>>+	}
>>+	if (!*nr_zones)
>>+		return -EIO;
>>+
>>+	return 0;
>>+}
>>+
>>+int btrfs_get_dev_zone_info(struct btrfs_device *device)
>>+{
>>+	struct btrfs_zoned_device_info *zone_info = NULL;
>>+	struct block_device *bdev = device->bdev;
>>+	sector_t nr_sectors = bdev->bd_part->nr_sects;
>>+	sector_t sector = 0;
>>+	struct blk_zone *zones = NULL;
>>+	unsigned int i, nreported = 0, nr_zones;
>>+	unsigned int zone_sectors;
>>+	int ret;
>>+	char devstr[sizeof(device->fs_info->sb->s_id) +
>>+		    sizeof(" (device )") - 1];
>>+
>>+	if (!bdev_is_zoned(bdev))
>>+		return 0;
>>+
>>+	zone_info = kzalloc(sizeof(*zone_info), GFP_KERNEL);
>>+	if (!zone_info)
>>+		return -ENOMEM;
>>+
>>+	zone_sectors = bdev_zone_sectors(bdev);
>>+	ASSERT(is_power_of_2(zone_sectors));
>>+	zone_info->zone_size = (u64)zone_sectors << SECTOR_SHIFT;
>>+	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
>>+	zone_info->nr_zones = nr_sectors >> ilog2(bdev_zone_sectors(bdev));
>>+	if (!IS_ALIGNED(nr_sectors, zone_sectors))
>>+		zone_info->nr_zones++;
>>+
>>+	zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
>>+	if (!zone_info->seq_zones) {
>>+		ret = -ENOMEM;
>>+		goto free_zone_info;
>>+	}
>>+
>>+	zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
>>+	if (!zone_info->empty_zones) {
>>+		ret = -ENOMEM;
>>+		goto free_seq_zones;
>>+	}
>>+
>>+	zones = kcalloc(BTRFS_REPORT_NR_ZONES,
>>+			sizeof(struct blk_zone), GFP_KERNEL);
>>+	if (!zones) {
>>+		ret = -ENOMEM;
>>+		goto free_empty_zones;
>>+	}
>>+
>>+	/* Get zones type */
>>+	while (sector < nr_sectors) {
>>+		nr_zones = BTRFS_REPORT_NR_ZONES;
>>+		ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT, zones,
>>+					  &nr_zones);
>>+		if (ret)
>>+			goto free_zones;
>>+
>>+		for (i = 0; i < nr_zones; i++) {
>>+			if (zones[i].type == BLK_ZONE_TYPE_SEQWRITE_REQ)
>>+				set_bit(nreported, zone_info->seq_zones);
>>+			if (zones[i].cond == BLK_ZONE_COND_EMPTY)
>>+				set_bit(nreported, zone_info->empty_zones);
>>+			nreported++;
>>+		}
>>+		sector = zones[nr_zones - 1].start + zones[nr_zones - 1].len;
>>+	}
>>+
>>+	if (nreported != zone_info->nr_zones) {
>>+		btrfs_err_in_rcu(device->fs_info,
>>+				 "inconsistent number of zones on %s (%u / %u)",
>>+				 rcu_str_deref(device->name), nreported,
>>+				 zone_info->nr_zones);
>>+		ret = -EIO;
>>+		goto free_zones;
>>+	}
>>+
>>+	kfree(zones);
>>+
>>+	device->zone_info = zone_info;
>>+
>>+	devstr[0] = 0;
>>+	if (device->fs_info)
>>+		snprintf(devstr, sizeof(devstr), " (device %s)",
>>+			 device->fs_info->sb->s_id);
>>+
>>+	rcu_read_lock();
>>+	pr_info(
>>+"BTRFS info%s: host-%s zoned block device %s, %u zones of %llu sectors",
>>+		devstr,
>>+		bdev_zoned_model(bdev) == BLK_ZONED_HM ? "managed" : "aware",
>>+		rcu_str_deref(device->name), zone_info->nr_zones,
>>+		zone_info->zone_size >> SECTOR_SHIFT);
>>+	rcu_read_unlock();
>>+
>>+	return 0;
>>+
>>+free_zones:
>>+	kfree(zones);
>>+free_empty_zones:
>>+	bitmap_free(zone_info->empty_zones);
>>+free_seq_zones:
>>+	bitmap_free(zone_info->seq_zones);
>>+free_zone_info:
>
>bitmap_free is just a kfree which handles NULL pointers properly, so 
>you only need one goto here for cleaning up the zone_info.  Once 
>that's fixed you can add
>
>Reviewed-by: Josef Bacik <josef@toxicpanda.com>
>
>Josef

Ah, then, I think I can simplify the code to use one "out" label and
kfree/bitmap_free both zones and zone_info.

Thanks,

Patch
diff mbox series

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 82200dbca5ac..64aaeed397a4 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -16,6 +16,7 @@  btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
 btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
 btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o
+btrfs-$(CONFIG_BLK_DEV_ZONED) += hmzoned.o
 
 btrfs-$(CONFIG_BTRFS_FS_RUN_SANITY_TESTS) += tests/free-space-tests.o \
 	tests/extent-buffer-tests.o tests/btrfs-tests.o \
diff --git a/fs/btrfs/hmzoned.c b/fs/btrfs/hmzoned.c
new file mode 100644
index 000000000000..6a13763d2916
--- /dev/null
+++ b/fs/btrfs/hmzoned.c
@@ -0,0 +1,168 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
+ * Authors:
+ *	Naohiro Aota	<naohiro.aota@wdc.com>
+ *	Damien Le Moal	<damien.lemoal@wdc.com>
+ */
+
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include "ctree.h"
+#include "volumes.h"
+#include "hmzoned.h"
+#include "rcu-string.h"
+
+/* Maximum number of zones to report per blkdev_report_zones() call */
+#define BTRFS_REPORT_NR_ZONES   4096
+
+static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
+			       struct blk_zone *zones, unsigned int *nr_zones)
+{
+	int ret;
+
+	ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, zones,
+				  nr_zones);
+	if (ret != 0) {
+		btrfs_err_in_rcu(device->fs_info,
+				 "get zone at %llu on %s failed %d", pos,
+				 rcu_str_deref(device->name), ret);
+		return ret;
+	}
+	if (!*nr_zones)
+		return -EIO;
+
+	return 0;
+}
+
+int btrfs_get_dev_zone_info(struct btrfs_device *device)
+{
+	struct btrfs_zoned_device_info *zone_info = NULL;
+	struct block_device *bdev = device->bdev;
+	sector_t nr_sectors = bdev->bd_part->nr_sects;
+	sector_t sector = 0;
+	struct blk_zone *zones = NULL;
+	unsigned int i, nreported = 0, nr_zones;
+	unsigned int zone_sectors;
+	int ret;
+	char devstr[sizeof(device->fs_info->sb->s_id) +
+		    sizeof(" (device )") - 1];
+
+	if (!bdev_is_zoned(bdev))
+		return 0;
+
+	zone_info = kzalloc(sizeof(*zone_info), GFP_KERNEL);
+	if (!zone_info)
+		return -ENOMEM;
+
+	zone_sectors = bdev_zone_sectors(bdev);
+	ASSERT(is_power_of_2(zone_sectors));
+	zone_info->zone_size = (u64)zone_sectors << SECTOR_SHIFT;
+	zone_info->zone_size_shift = ilog2(zone_info->zone_size);
+	zone_info->nr_zones = nr_sectors >> ilog2(bdev_zone_sectors(bdev));
+	if (!IS_ALIGNED(nr_sectors, zone_sectors))
+		zone_info->nr_zones++;
+
+	zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
+	if (!zone_info->seq_zones) {
+		ret = -ENOMEM;
+		goto free_zone_info;
+	}
+
+	zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
+	if (!zone_info->empty_zones) {
+		ret = -ENOMEM;
+		goto free_seq_zones;
+	}
+
+	zones = kcalloc(BTRFS_REPORT_NR_ZONES,
+			sizeof(struct blk_zone), GFP_KERNEL);
+	if (!zones) {
+		ret = -ENOMEM;
+		goto free_empty_zones;
+	}
+
+	/* Get zones type */
+	while (sector < nr_sectors) {
+		nr_zones = BTRFS_REPORT_NR_ZONES;
+		ret = btrfs_get_dev_zones(device, sector << SECTOR_SHIFT, zones,
+					  &nr_zones);
+		if (ret)
+			goto free_zones;
+
+		for (i = 0; i < nr_zones; i++) {
+			if (zones[i].type == BLK_ZONE_TYPE_SEQWRITE_REQ)
+				set_bit(nreported, zone_info->seq_zones);
+			if (zones[i].cond == BLK_ZONE_COND_EMPTY)
+				set_bit(nreported, zone_info->empty_zones);
+			nreported++;
+		}
+		sector = zones[nr_zones - 1].start + zones[nr_zones - 1].len;
+	}
+
+	if (nreported != zone_info->nr_zones) {
+		btrfs_err_in_rcu(device->fs_info,
+				 "inconsistent number of zones on %s (%u / %u)",
+				 rcu_str_deref(device->name), nreported,
+				 zone_info->nr_zones);
+		ret = -EIO;
+		goto free_zones;
+	}
+
+	kfree(zones);
+
+	device->zone_info = zone_info;
+
+	devstr[0] = 0;
+	if (device->fs_info)
+		snprintf(devstr, sizeof(devstr), " (device %s)",
+			 device->fs_info->sb->s_id);
+
+	rcu_read_lock();
+	pr_info(
+"BTRFS info%s: host-%s zoned block device %s, %u zones of %llu sectors",
+		devstr,
+		bdev_zoned_model(bdev) == BLK_ZONED_HM ? "managed" : "aware",
+		rcu_str_deref(device->name), zone_info->nr_zones,
+		zone_info->zone_size >> SECTOR_SHIFT);
+	rcu_read_unlock();
+
+	return 0;
+
+free_zones:
+	kfree(zones);
+free_empty_zones:
+	bitmap_free(zone_info->empty_zones);
+free_seq_zones:
+	bitmap_free(zone_info->seq_zones);
+free_zone_info:
+	kfree(zone_info);
+
+	return ret;
+}
+
+void btrfs_destroy_dev_zone_info(struct btrfs_device *device)
+{
+	struct btrfs_zoned_device_info *zone_info = device->zone_info;
+
+	if (!zone_info)
+		return;
+
+	bitmap_free(zone_info->seq_zones);
+	bitmap_free(zone_info->empty_zones);
+	kfree(zone_info);
+	device->zone_info = NULL;
+}
+
+int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
+		       struct blk_zone *zone)
+{
+	unsigned int nr_zones = 1;
+	int ret;
+
+	ret = btrfs_get_dev_zones(device, pos, zone, &nr_zones);
+	if (ret != 0 || !nr_zones)
+		return ret ? ret : -EIO;
+
+	return 0;
+}
diff --git a/fs/btrfs/hmzoned.h b/fs/btrfs/hmzoned.h
new file mode 100644
index 000000000000..0f8006f39aaf
--- /dev/null
+++ b/fs/btrfs/hmzoned.h
@@ -0,0 +1,92 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
+ * Authors:
+ *	Naohiro Aota	<naohiro.aota@wdc.com>
+ *	Damien Le Moal	<damien.lemoal@wdc.com>
+ */
+
+#ifndef BTRFS_HMZONED_H
+#define BTRFS_HMZONED_H
+
+struct btrfs_zoned_device_info {
+	/*
+	 * Number of zones, zone size and types of zones if bdev is a
+	 * zoned block device.
+	 */
+	u64 zone_size;
+	u8  zone_size_shift;
+	u32 nr_zones;
+	unsigned long *seq_zones;
+	unsigned long *empty_zones;
+};
+
+#ifdef CONFIG_BLK_DEV_ZONED
+int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
+		       struct blk_zone *zone);
+int btrfs_get_dev_zone_info(struct btrfs_device *device);
+void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
+#else /* CONFIG_BLK_DEV_ZONED */
+static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
+				     struct blk_zone *zone)
+{
+	return 0;
+}
+static inline int btrfs_get_dev_zone_info(struct btrfs_device *device)
+{
+	return 0;
+}
+static inline void btrfs_destroy_dev_zone_info(struct btrfs_device *device) { }
+#endif
+
+static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
+{
+	struct btrfs_zoned_device_info *zone_info = device->zone_info;
+
+	if (!zone_info)
+		return false;
+
+	return test_bit(pos >> zone_info->zone_size_shift,
+			zone_info->seq_zones);
+}
+
+static inline bool btrfs_dev_is_empty_zone(struct btrfs_device *device, u64 pos)
+{
+	struct btrfs_zoned_device_info *zone_info = device->zone_info;
+
+	if (!zone_info)
+		return true;
+
+	return test_bit(pos >> zone_info->zone_size_shift,
+			zone_info->empty_zones);
+}
+
+static inline void btrfs_dev_set_empty_zone_bit(struct btrfs_device *device,
+						u64 pos, bool set)
+{
+	struct btrfs_zoned_device_info *zone_info = device->zone_info;
+	unsigned int zno;
+
+	if (!zone_info)
+		return;
+
+	zno = pos >> zone_info->zone_size_shift;
+	if (set)
+		set_bit(zno, zone_info->empty_zones);
+	else
+		clear_bit(zno, zone_info->empty_zones);
+}
+
+static inline void btrfs_dev_set_zone_empty(struct btrfs_device *device,
+					    u64 pos)
+{
+	btrfs_dev_set_empty_zone_bit(device, pos, true);
+}
+
+static inline void btrfs_dev_clear_zone_empty(struct btrfs_device *device,
+					      u64 pos)
+{
+	btrfs_dev_set_empty_zone_bit(device, pos, false);
+}
+
+#endif
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d8e5560db285..18ea8dfce244 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -30,6 +30,7 @@ 
 #include "tree-checker.h"
 #include "space-info.h"
 #include "block-group.h"
+#include "hmzoned.h"
 
 const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
 	[BTRFS_RAID_RAID10] = {
@@ -366,6 +367,7 @@  void btrfs_free_device(struct btrfs_device *device)
 	rcu_string_free(device->name);
 	extent_io_tree_release(&device->alloc_state);
 	bio_put(device->flush_bio);
+	btrfs_destroy_dev_zone_info(device);
 	kfree(device);
 }
 
@@ -650,6 +652,11 @@  static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
 	clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
 	device->mode = flags;
 
+	/* Get zone type information of zoned block devices */
+	ret = btrfs_get_dev_zone_info(device);
+	if (ret != 0)
+		goto error_brelse;
+
 	fs_devices->open_devices++;
 	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
 	    device->devid != BTRFS_DEV_REPLACE_DEVID) {
@@ -2421,6 +2428,14 @@  int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 	}
 	rcu_assign_pointer(device->name, name);
 
+	device->fs_info = fs_info;
+	device->bdev = bdev;
+
+	/* Get zone type information of zoned block devices */
+	ret = btrfs_get_dev_zone_info(device);
+	if (ret)
+		goto error_free_device;
+
 	trans = btrfs_start_transaction(root, 0);
 	if (IS_ERR(trans)) {
 		ret = PTR_ERR(trans);
@@ -2437,8 +2452,6 @@  int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 					 fs_info->sectorsize);
 	device->disk_total_bytes = device->total_bytes;
 	device->commit_total_bytes = device->total_bytes;
-	device->fs_info = fs_info;
-	device->bdev = bdev;
 	set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
 	clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
 	device->mode = FMODE_EXCL;
@@ -2571,6 +2584,7 @@  int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 		sb->s_flags |= SB_RDONLY;
 	if (trans)
 		btrfs_end_transaction(trans);
+	btrfs_destroy_dev_zone_info(device);
 error_free_device:
 	btrfs_free_device(device);
 error:
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index fc1b564b9cfe..70cabe65f72a 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -53,6 +53,8 @@  struct btrfs_io_geometry {
 #define BTRFS_DEV_STATE_REPLACE_TGT	(3)
 #define BTRFS_DEV_STATE_FLUSH_SENT	(4)
 
+struct btrfs_zoned_device_info;
+
 struct btrfs_device {
 	struct list_head dev_list; /* device_list_mutex */
 	struct list_head dev_alloc_list; /* chunk mutex */
@@ -66,6 +68,8 @@  struct btrfs_device {
 
 	struct block_device *bdev;
 
+	struct btrfs_zoned_device_info *zone_info;
+
 	/* the mode sent to blkdev_get */
 	fmode_t mode;