btrfs: fix structs where bitfields and spinlock/atomic share 8B word

On ia64, powerpc64 and sparc64 the bitfield is modified through a RMW cycle and current
gcc rewrites the adjacent 4B word, which in case of a spinlock or atomic has
disaterous effect.

https://lkml.org/lkml/2012/2/1/220

Signed-off-by: David Sterba <dsterba@suse.cz>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index 33a7890b1f40..1195f09761fe 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -26,8 +26,8 @@ struct extent_map {
         unsigned long flags;
         struct block_device *bdev;
         atomic_t refs;
-        unsigned int in_tree:1;
-        unsigned int compress_type:4;
+        unsigned int in_tree;
+        unsigned int compress_type;
 };
 
 struct extent_map_tree {