2 files changed, 4 insertions, 1 deletions
diff --git a/src/util.c b/src/util.c
index 92b4d20..21b2b69 100644
--- a/src/util.c
+++ b/src/util.c
@@ -162,7 +162,7 @@ writezeroes(int fd, void *buf, size_t bufsize, size_t n)
 {
 	size_t p, m;
 	for (p = 0; p < n; p += m) {
-		m = bufsize < n - p ? bufsize : n - p;
+		m = MIN(bufsize, n - p);
 		if (writeall(fd, buf, m))
 			return -1;
 	}
diff --git a/src/util.h b/src/util.h
index a9704ec..d948452 100644
--- a/src/util.h
+++ b/src/util.h
@@ -2,6 +2,9 @@
 #include "arg.h"
 
 #define ELEMENTSOF(ARRAY) (sizeof(ARRAY) / sizeof(*(ARRAY)))
+#define MIN(A, B)         ((A) < (B) ? (A) : (B))
+#define MAX(A, B)         ((A) > (B) ? (A) : (B))
+#define CLIP(A, B, C)     ((B) < (A) ? (A) : (B) > (C) ? (C) : (B))
 
 #define USAGE(SYNOPSIS)\
 	static void usage(void)\