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btrfs: zoned: cache reported zone during mount

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When mounting a device, we are reporting the zones twice: once for
checking the zone attributes in btrfs_get_dev_zone_info and once for
loading block groups' zone info in
btrfs_load_block_group_zone_info(). With a lot of block groups, that
leads to a lot of REPORT ZONE commands and slows down the mount
process.

This patch introduces a zone info cache in struct
btrfs_zoned_device_info. The cache is populated while in
btrfs_get_dev_zone_info() and used for
btrfs_load_block_group_zone_info() to reduce the number of REPORT ZONE
commands. The zone cache is then released after loading the block
groups, as it will not be much effective during the run time.

Benchmark: Mount an HDD with 57,007 block groups
Before patch: 171.368 seconds
After patch: 64.064 seconds

While it still takes a minute due to the slowness of loading all the
block groups, the patch reduces the mount time by 1/3.

Link: https://lore.kernel.org/linux-btrfs/CAHQ7scUiLtcTqZOMMY5kbWUBOhGRwKo6J6wYPT5WY+C=cD49nQ@mail.gmail.com/
Fixes: 5b31646898 ("btrfs: get zone information of zoned block devices")
CC: stable@vger.kernel.org
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Naohiro Aota
2021-11-11 14:14:38 +09:00
committed by David Sterba
parent d21deec5e7
commit 16beac87e9
5 changed files with 87 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
fs/btrfs/zoned.h
View File

@ -28,6 +28,7 @@ struct btrfs_zoned_device_info {
unsigned long *seq_zones;
unsigned long *empty_zones;
unsigned long *active_zones;
struct blk_zone *zone_cache;
struct blk_zone sb_zones[2 * BTRFS_SUPER_MIRROR_MAX];
};
@ -35,7 +36,7 @@ struct btrfs_zoned_device_info {
int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
struct blk_zone *zone);
int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info);
int btrfs_get_dev_zone_info(struct btrfs_device *device);
int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache);
void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info);
int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info);
@ -76,6 +77,7 @@ bool btrfs_can_activate_zone(struct btrfs_fs_devices *fs_devices,
void btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info, u64 logical,
u64 length);
void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg);
void btrfs_free_zone_cache(struct btrfs_fs_info *fs_info);
#else /* CONFIG_BLK_DEV_ZONED */
static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
struct blk_zone *zone)
@ -88,7 +90,8 @@ static inline int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_i
return 0;
}
static inline int btrfs_get_dev_zone_info(struct btrfs_device *device)
static inline int btrfs_get_dev_zone_info(struct btrfs_device *device,
bool populate_cache)
{
return 0;
}
@ -232,6 +235,7 @@ static inline void btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info,
static inline void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg) { }
static inline void btrfs_free_zone_cache(struct btrfs_fs_info *fs_info) { }
#endif
static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)