NFSv4: Honour the 'opened' parameter in the atomic_open() filesystem method

Determine if we've created a new file by examining the directory change
attribute and/or the O_EXCL flag.

This fixes a regression when doing a non-exclusive create of a new file.
If the FILE_CREATED flag is not set, the atomic_open() command will
perform full file access permissions checks instead of just checking
for MAY_OPEN.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/nfs_xdr.h

@@ -1455,7 +1455,8 @@ struct nfs_rpc_ops {
 	struct inode * (*open_context) (struct inode *dir,
 				struct nfs_open_context *ctx,
 				int open_flags,
-				struct iattr *iattr);
+				struct iattr *iattr,
+				int *);
 	int (*have_delegation)(struct inode *, fmode_t);
 	int (*return_delegation)(struct inode *);
 	struct nfs_client *(*alloc_client) (const struct nfs_client_initdata *);