fs: remove FS_COW_FL

FS_COW_FL and FS_NOCOW_FL were newly introduced to control per file
COW in btrfs, but FS_NOCOW_FL is sufficient.

The fact is we don't have corresponding BTRFS_INODE_COW flag.

COW is default, and FS_NOCOW_FL can be used to switch off COW for
a single file.

If we mount btrfs with nodatacow, a newly created file will be set with
the FS_NOCOW_FL flag. So to turn on COW for it, we can just clear the
FS_NOCOW_FL flag.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 0 insertions, 1 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index de9dd8119b71..56a41412903d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -365,7 +365,6 @@ struct inodes_stat_t {
 #define FS_EXTENT_FL                    0x00080000 /* Extents */
 #define FS_DIRECTIO_FL                  0x00100000 /* Use direct i/o */
 #define FS_NOCOW_FL                     0x00800000 /* Do not cow file */
-#define FS_COW_FL                       0x02000000 /* Cow file */
 #define FS_RESERVED_FL                  0x80000000 /* reserved for ext2 lib */
 
 #define FS_FL_USER_VISIBLE              0x0003DFFF /* User visible flags */