[PATCH RFC PATCH 3/3] btrfs: zoned: kick cleaner kthread if low on space

[Johannes Thumshirn <jth@kernel.org>]

From: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Kick the cleaner kthread on chunk allocation if we're slowly running out
of usable space on a zoned filesystem.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 fs/btrfs/zoned.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index fb8707f4cab5..25c1a17873db 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -1040,6 +1040,7 @@ int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
 u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
 				 u64 hole_end, u64 num_bytes)
 {
+	struct btrfs_fs_info *fs_info = device->fs_info;
 	struct btrfs_zoned_device_info *zinfo = device->zone_info;
 	const u8 shift = zinfo->zone_size_shift;
 	u64 nzones = num_bytes >> shift;
@@ -1051,6 +1052,11 @@ u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
 	ASSERT(IS_ALIGNED(hole_start, zinfo->zone_size));
 	ASSERT(IS_ALIGNED(num_bytes, zinfo->zone_size));
 
+	if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags) &&
+	    btrfs_zoned_should_reclaim(fs_info)) {
+		wake_up_process(fs_info->cleaner_kthread);
+	}
+
 	while (pos < hole_end) {
 		begin = pos >> shift;
 		end = begin + nzones;

-- 
2.35.3