From: Anand Jain <anand.jain@oracle.com>
To: Damien Le Moal <Damien.LeMoal@wdc.com>,
Naohiro Aota <Naohiro.Aota@wdc.com>,
"linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>,
David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>,
Nikolay Borisov <nborisov@suse.com>,
Matias Bjorling <Matias.Bjorling@wdc.com>,
Johannes Thumshirn <jthumshirn@suse.de>,
Hannes Reinecke <hare@suse.com>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH v3 02/27] btrfs: Get zone information of zoned block devices
Date: Sat, 17 Aug 2019 07:47:36 +0800 [thread overview]
Message-ID: <8e523d2c-f945-44bd-e6f2-c38037af2bf2@oracle.com> (raw)
In-Reply-To: <BYAPR04MB5816442B6CD412BC6925D90AE7AF0@BYAPR04MB5816.namprd04.prod.outlook.com>
On 8/16/19 10:19 PM, Damien Le Moal wrote:
> On 2019/08/15 21:47, Anand Jain wrote:
>> On 8/8/19 5:30 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_zonetypes(). 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 | 2 +-
>>> fs/btrfs/hmzoned.c | 162 +++++++++++++++++++++++++++++++++++++++++++++
>>> fs/btrfs/hmzoned.h | 79 ++++++++++++++++++++++
>>> fs/btrfs/volumes.c | 18 ++++-
>>> fs/btrfs/volumes.h | 4 ++
>>> 5 files changed, 262 insertions(+), 3 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 76a843198bcb..8d93abb31074 100644
>>> --- a/fs/btrfs/Makefile
>>> +++ b/fs/btrfs/Makefile
>>> @@ -11,7 +11,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
>>> compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
>>> reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \
>>> uuid-tree.o props.o free-space-tree.o tree-checker.o space-info.o \
>>> - block-rsv.o delalloc-space.o
>>> + block-rsv.o delalloc-space.o hmzoned.o
>>>
>>> btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
>>> btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
>>> diff --git a/fs/btrfs/hmzoned.c b/fs/btrfs/hmzoned.c
>>> new file mode 100644
>>> index 000000000000..bfd04792dd62
>>> --- /dev/null
>>> +++ b/fs/btrfs/hmzoned.c
>>> @@ -0,0 +1,162 @@
>>> +// 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_ret,
>>> + unsigned int *nr_zones, gfp_t gfp_mask)
>>> +{
>>> + struct blk_zone *zones = *zones_ret;
>>> + int ret;
>>> +
>>> + if (!zones) {
>>> + zones = kcalloc(*nr_zones, sizeof(struct blk_zone), GFP_KERNEL);
>>> + if (!zones)
>>> + return -ENOMEM;
>>> + }
>>> +
>>> + ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT,
>>> + zones, nr_zones, gfp_mask);
>>> + 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;
>>> +
>>> + *zones_ret = zones;
>>> +
>>> + 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;
>>> +
>>> + 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 (nr_sectors & (bdev_zone_sectors(bdev) - 1))
>>> + zone_info->nr_zones++;
>>> +
>>> + zone_info->seq_zones = kcalloc(BITS_TO_LONGS(zone_info->nr_zones),
>>> + sizeof(*zone_info->seq_zones),
>>> + GFP_KERNEL);
>>> + if (!zone_info->seq_zones) {
>>> + ret = -ENOMEM;
>>> + goto out;
>>> + }
>>> +
>>> + zone_info->empty_zones = kcalloc(BITS_TO_LONGS(zone_info->nr_zones),
>>> + sizeof(*zone_info->empty_zones),
>>> + GFP_KERNEL);
>>> + if (!zone_info->empty_zones) {
>>> + ret = -ENOMEM;
>>> + goto out;
>>> + }
>>> +
>>> + /* 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, GFP_KERNEL);
>>
>>
>> How many zones do we see in a disk? Not many I presume.
>
> A 15 TB SMR drive with 256 MB zones (which is a failry common value for products
> out there) has over 55,000 zones. "Not many" is subjective... I personally
> consider 55000 a large number and that one should take care to write appropriate
> code to manage that many objects.
Agree that's pretty large.
>> Here the allocation for %zones is inconsistent for each zone, unless
>> there is substantial performance benefits, a consistent flow of
>> alloc/free is fine as it makes the code easy to read and verify.
>
> I do not understand your comment here. btrfs_get_dev_zones() will allocate and
> fill the zones array with at most BTRFS_REPORT_NR_ZONES zones descriptors on the
> first call. On subsequent calls, the same array is reused until information on
> all zones of the disk is obtained. "the allocation for %zones is inconsistent
> for each zone" does not makes much sense. What exactly do you mean ?
btrfs_get_dev_zones() allocates the memory for %zones_ret, and expects
its parent function btrfs_get_dev_zone_info() to free, instead can we
have alloc and free in the parent function btrfs_get_dev_zone_info().
Thanks, Anand
>>
>>
>> Thanks, Anand
>>
>>> + if (ret)
>>> + goto out;
>>> +
>>> + 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 out;
>>> + }
>>> +
>>> + device->zone_info = zone_info;
>>> +
>>> + btrfs_info_in_rcu(
>>> + device->fs_info,
>>> + "host-%s zoned block device %s, %u zones of %llu sectors",
>>> + bdev_zoned_model(bdev) == BLK_ZONED_HM ? "managed" : "aware",
>>> + rcu_str_deref(device->name), zone_info->nr_zones,
>>> + zone_info->zone_size >> SECTOR_SHIFT);
>>> +
>>> +out:
>>> + kfree(zones);
>>> +
>>> + if (ret) {
>>> + kfree(zone_info->seq_zones);
>>> + kfree(zone_info->empty_zones);
>>> + 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;
>>> +
>>> + kfree(zone_info->seq_zones);
>>> + kfree(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, gfp_t gfp_mask)
>>> +{
>>> + unsigned int nr_zones = 1;
>>> + int ret;
>>> +
>>> + ret = btrfs_get_dev_zones(device, pos, &zone, &nr_zones, gfp_mask);
>>> + 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..ffc70842135e
>>> --- /dev/null
>>> +++ b/fs/btrfs/hmzoned.h
>>> @@ -0,0 +1,79 @@
>>> +/* 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;
>>> +};
>>> +
>>> +int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
>>> + struct blk_zone *zone, gfp_t gfp_mask);
>>> +int btrfs_get_dev_zone_info(struct btrfs_device *device);
>>> +void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
>>> +
>>> +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 d74b74ca07af..8e5a894e7bde 100644
>>> --- a/fs/btrfs/volumes.c
>>> +++ b/fs/btrfs/volumes.c
>>> @@ -29,6 +29,7 @@
>>> #include "sysfs.h"
>>> #include "tree-checker.h"
>>> #include "space-info.h"
>>> +#include "hmzoned.h"
>>>
>>> const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
>>> [BTRFS_RAID_RAID10] = {
>>> @@ -342,6 +343,7 @@ 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);
>>> }
>>>
>>> @@ -847,6 +849,11 @@ 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) {
>>> @@ -2598,6 +2605,14 @@ 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);
>>> @@ -2614,8 +2629,6 @@ 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;
>>> @@ -2756,6 +2769,7 @@ 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 7f6aa1816409..5da1f354db93 100644
>>> --- a/fs/btrfs/volumes.h
>>> +++ b/fs/btrfs/volumes.h
>>> @@ -57,6 +57,8 @@ 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 */
>>> @@ -77,6 +79,8 @@ struct btrfs_device {
>>>
>>> struct block_device *bdev;
>>>
>>> + struct btrfs_zoned_device_info *zone_info;
>>> +
>>> /* the mode sent to blkdev_get */
>>> fmode_t mode;
>>>
>>>
>>
>>
>
>
next prev parent reply other threads:[~2019-08-16 23:48 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-08 9:30 [PATCH v3 00/27] btrfs zoned block device support Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 01/27] btrfs: introduce HMZONED feature flag Naohiro Aota
2019-08-16 4:49 ` Anand Jain
2019-08-08 9:30 ` [PATCH v3 02/27] btrfs: Get zone information of zoned block devices Naohiro Aota
2019-08-16 4:44 ` Anand Jain
2019-08-16 14:19 ` Damien Le Moal
2019-08-16 23:47 ` Anand Jain [this message]
2019-08-16 23:55 ` Damien Le Moal
2019-08-08 9:30 ` [PATCH v3 03/27] btrfs: Check and enable HMZONED mode Naohiro Aota
2019-08-16 5:46 ` Anand Jain
2019-08-16 14:23 ` Damien Le Moal
2019-08-16 23:56 ` Anand Jain
2019-08-17 0:05 ` Damien Le Moal
2019-08-20 5:07 ` Naohiro Aota
2019-08-20 13:05 ` David Sterba
2019-08-08 9:30 ` [PATCH v3 04/27] btrfs: disallow RAID5/6 in " Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 05/27] btrfs: disallow space_cache " Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 06/27] btrfs: disallow NODATACOW " Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 07/27] btrfs: disable tree-log " Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 08/27] btrfs: disable fallocate " Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 09/27] btrfs: align device extent allocation to zone boundary Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 10/27] btrfs: do sequential extent allocation in HMZONED mode Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 11/27] btrfs: make unmirroed BGs readonly only if we have at least one writable BG Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 12/27] btrfs: ensure metadata space available on/after degraded mount in HMZONED Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 13/27] btrfs: reset zones of unused block groups Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 14/27] btrfs: limit super block locations in HMZONED mode Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 15/27] btrfs: redirty released extent buffers in sequential BGs Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 16/27] btrfs: serialize data allocation and submit IOs Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 17/27] btrfs: implement atomic compressed IO submission Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 18/27] btrfs: support direct write IO in HMZONED Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 19/27] btrfs: serialize meta IOs on HMZONED mode Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 20/27] btrfs: wait existing extents before truncating Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 21/27] btrfs: avoid async checksum/submit on HMZONED mode Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 22/27] btrfs: disallow mixed-bg in " Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 23/27] btrfs: disallow inode_cache " Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 24/27] btrfs: support dev-replace " Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 25/27] btrfs: enable relocation " Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 26/27] btrfs: relocate block group to repair IO failure in HMZONED Naohiro Aota
2019-08-08 9:30 ` [PATCH v3 27/27] btrfs: enable to mount HMZONED incompat flag Naohiro Aota
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