NFSv4: Add FMODE_CAN_ODIRECT after successful open of a NFS4.x file

Commit a2ad63da ("VFS: add FMODE_CAN_ODIRECT file flag")
added the FMODE_CAN_ODIRECT flag for NFSv3 but neglected to add
it for NFSv4.x.  This causes direct io on NFSv4.x to fail open
with EINVAL:
  mount -o vers=4.2 127.0.0.1:/export /mnt/nfs4
  dd if=/dev/zero of=/mnt/nfs4/file.bin bs=128k count=1 oflag=direct
  dd: failed to open '/mnt/nfs4/file.bin': Invalid argument
  dd of=/dev/null if=/mnt/nfs4/file.bin bs=128k count=1 iflag=direct
  dd: failed to open '/mnt/dir1/file1.bin': Invalid argument

Fixes: a2ad63da ("VFS: add FMODE_CAN_ODIRECT file flag")
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/dir.c

@@ -2124,6 +2124,7 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
 		}
 		goto out;
 	}
+	file->f_mode |= FMODE_CAN_ODIRECT;
 
 	err = nfs_finish_open(ctx, ctx->dentry, file, open_flags);
 	trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);

fs/nfs/nfs4file.c

@@ -93,6 +93,7 @@ nfs4_file_open(struct inode *inode, struct file *filp)
 	nfs_file_set_open_context(filp, ctx);
 	nfs_fscache_open_file(inode, filp);
 	err = 0;
+	filp->f_mode |= FMODE_CAN_ODIRECT;
 
 out_put_ctx:
 	put_nfs_open_context(ctx);