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authorNaohiro Aota <naohiro.aota@wdc.com>2021-02-04 19:21:52 +0900
committerDavid Sterba <dsterba@suse.com>2021-02-09 02:46:03 +0100
commit169e0da91a21a571093feb8ff84c7e9229e64c08 (patch)
tree22c27a901122d21acc03d47b53b55b84946e8fd4 /fs/btrfs/sysfs.c
parenta94794d50d788d4735fd8f656ac8c0510117457d (diff)
btrfs: zoned: track unusable bytes for zones
In a zoned filesystem a once written then freed region is not usable until the underlying zone has been reset. So we need to distinguish such unusable space from usable free space. Therefore we need to introduce the "zone_unusable" field to the block group structure, and "bytes_zone_unusable" to the space_info structure to track the unusable space. Pinned bytes are always reclaimed to the unusable space. But, when an allocated region is returned before using e.g., the block group becomes read-only between allocation time and reservation time, we can safely return the region to the block group. For the situation, this commit introduces "btrfs_add_free_space_unused". This behaves the same as btrfs_add_free_space() on regular filesystem. On zoned filesystems, it rewinds the allocation offset. Because the read-only bytes tracks free but unusable bytes when the block group is read-only, we need to migrate the zone_unusable bytes to read-only bytes when a block group is marked read-only. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/sysfs.c')
-rw-r--r--fs/btrfs/sysfs.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 19b9fffa2c9c..6eb1c50fa98c 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -666,6 +666,7 @@ SPACE_INFO_ATTR(bytes_pinned);
SPACE_INFO_ATTR(bytes_reserved);
SPACE_INFO_ATTR(bytes_may_use);
SPACE_INFO_ATTR(bytes_readonly);
+SPACE_INFO_ATTR(bytes_zone_unusable);
SPACE_INFO_ATTR(disk_used);
SPACE_INFO_ATTR(disk_total);
BTRFS_ATTR(space_info, total_bytes_pinned,
@@ -679,6 +680,7 @@ static struct attribute *space_info_attrs[] = {
BTRFS_ATTR_PTR(space_info, bytes_reserved),
BTRFS_ATTR_PTR(space_info, bytes_may_use),
BTRFS_ATTR_PTR(space_info, bytes_readonly),
+ BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
BTRFS_ATTR_PTR(space_info, disk_used),
BTRFS_ATTR_PTR(space_info, disk_total),
BTRFS_ATTR_PTR(space_info, total_bytes_pinned),