[PATCH 3/3] btrfs: zoned: do not account freed region of read-only block group as zone_unusable

[Naohiro Aota]

We migrate zone unusable bytes to read-only bytes when a block group is set
to read-only, and account all the free region as bytes_readonly. Thus, we
should not increase block_group->zone_unusable when the block group is
read-only.

Fixes: 169e0da91a21 ("btrfs: zoned: track unusable bytes for zones")
Signed-off-by: Naohiro Aota <naohiro.a...@wdc.com>
---
 fs/btrfs/free-space-cache.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 711a6a751ae9..81835153f747 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2555,7 +2555,12 @@ static int __btrfs_add_free_space_zoned(struct 
btrfs_block_group *block_group,
        to_unusable = size - to_free;
 
        ctl->free_space += to_free;
-       block_group->zone_unusable += to_unusable;
+       /*
+        * If the block group is read-only, we should account freed
+        * space into bytes_readonly.
+        */
+       if (!block_group->ro)
+               block_group->zone_unusable += to_unusable;
        spin_unlock(&ctl->tree_lock);
        if (!used) {
                spin_lock(&block_group->lock);
-- 
2.30.1