[PATCH] inode-diet: Move i_cdev into a union

Move the i_cdev pointer in struct inode into a union.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/file_table.c

@@ -169,7 +169,7 @@ void fastcall __fput(struct file *file)
 	if (file->f_op && file->f_op->release)
 		file->f_op->release(inode, file);
 	security_file_free(file);
-	if (unlikely(inode->i_cdev != NULL))
+	if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL))
 		cdev_put(inode->i_cdev);
 	fops_put(file->f_op);
 	if (file->f_mode & FMODE_WRITE)

fs/inode.c

@@ -256,7 +256,7 @@ void clear_inode(struct inode *inode)
 		inode->i_sb->s_op->clear_inode(inode);
 	if (S_ISBLK(inode->i_mode) && inode->i_bdev)
 		bd_forget(inode);
-	if (inode->i_cdev)
+	if (S_ISCHR(inode->i_mode) && inode->i_cdev)
 		cd_forget(inode);
 	inode->i_state = I_CLEAR;
 }

include/linux/fs.h

@@ -532,8 +532,8 @@ struct inode {
 	union {
 		struct pipe_inode_info	*i_pipe;
 		struct block_device	*i_bdev;
+		struct cdev		*i_cdev;
 	};
-	struct cdev		*i_cdev;
 	int			i_cindex;
 
 	__u32			i_generation;