On 12/21/20 10:49 PM, Naohiro Aota wrote:
In zoned btrfs a region that was once written then freed is not usable
until we reset the underlying zone. 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 btrfs. On zoned btrfs, it rewinds the
allocation offset.
Signed-off-by: Naohiro Aota <naohiro.a...@wdc.com>
Reviewed-by: Josef Bacik <jo...@toxicpanda.com>
Thanks,
Josef
