[PATCH 1/2] btrfs: remove the zoned/zone_size union in struct btrfs_fs_info

[Christoph Hellwig <hch@lst.de>]

Reading a value from a different member of a union is not just a great
way to obsfucate code, but also creates an aliasing violation.  Switch
btrfs_is_zoned to look at ->zone_size and remove the union.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/btrfs/ctree.h | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b7631b88426e3..0edcce6d2db64 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1045,10 +1045,7 @@ struct btrfs_fs_info {
 	 * Zone size > 0 when in ZONED mode, otherwise it's used for a check
 	 * if the mode is enabled
 	 */
-	union {
-		u64 zone_size;
-		u64 zoned;
-	};
+	u64 zone_size;
 
 	struct mutex zoned_meta_io_lock;
 	spinlock_t treelog_bg_lock;
@@ -3928,7 +3925,7 @@ static inline int btrfs_is_testing(struct btrfs_fs_info *fs_info)
 
 static inline bool btrfs_is_zoned(const struct btrfs_fs_info *fs_info)
 {
-	return fs_info->zoned != 0;
+	return fs_info->zone_size > 0;
 }
 
 static inline bool btrfs_is_data_reloc_root(const struct btrfs_root *root)
-- 
2.30.2