NFS: Clean-up: Define macros for maximum host and export path name lengths

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/super.c

@@ -867,12 +867,12 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
 		}
 	}
 
-	p = nfs_copy_user_string(NULL, &data->hostname, 256);
+	p = nfs_copy_user_string(NULL, &data->hostname, NFS4_MAXNAMLEN);
 	if (IS_ERR(p))
 		goto out_err;
 	hostname = p;
 
-	p = nfs_copy_user_string(NULL, &data->mnt_path, 1024);
+	p = nfs_copy_user_string(NULL, &data->mnt_path, NFS4_MAXPATHLEN);
 	if (IS_ERR(p))
 		goto out_err;
 	mntpath = p;

include/linux/nfs_mount.h

@@ -37,7 +37,7 @@ struct nfs_mount_data {
 	int		acdirmin;		/* 1 */
 	int		acdirmax;		/* 1 */
 	struct sockaddr_in addr;		/* 1 */
-	char		hostname[256];		/* 1 */
+	char		hostname[NFS_MAXNAMLEN + 1];		/* 1 */
 	int		namlen;			/* 2 */
 	unsigned int	bsize;			/* 3 */
 	struct nfs3_fh	root;			/* 4 */