add -W to specify window size.

various other little fixes.
diff --git a/src/lib9/create.c b/src/lib9/create.c
index 97f6e7e..eaea479 100644
--- a/src/lib9/create.c
+++ b/src/lib9/create.c
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE	/* for Linux O_DIRECT */
 #include <u.h>
 #define NOPLAN9DEFINES
 #include <libc.h>
@@ -25,6 +26,10 @@
 	}else{
 		umode = (mode&3)|O_CREAT|O_TRUNC;
 		mode &= ~(3|OTRUNC);
+		if(mode&ODIRECT){
+			umode |= O_DIRECT;
+			mode &= ~ODIRECT;
+		}
 		if(mode&OEXCL){
 			umode |= O_EXCL;
 			mode &= ~OEXCL;