perf tools: Create write_padded routine out of __dsos__write_buildid_table

Will be used by other options where padding is needed.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1262629169-22797-3-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

tools/perf/util/header.c

@@ -173,6 +173,20 @@ static int do_write(int fd, const void *buf, size_t size)
 	return 0;
 }
 
+#define NAME_ALIGN 64
+
+static int write_padded(int fd, const void *bf, size_t count,
+			size_t count_aligned)
+{
+	static const char zero_buf[NAME_ALIGN];
+	int err = do_write(fd, bf, count);
+
+	if (!err)
+		err = do_write(fd, zero_buf, count_aligned - count);
+
+	return err;
+}
+
 #define dsos__for_each_with_build_id(pos, head)	\
 	list_for_each_entry(pos, head, node)	\
 		if (!pos->has_build_id)		\
@@ -181,9 +195,7 @@ static int do_write(int fd, const void *buf, size_t size)
 
 static int __dsos__write_buildid_table(struct list_head *head, int fd)
 {
-#define NAME_ALIGN	64
 	struct dso *pos;
-	static const char zero_buf[NAME_ALIGN];
 
 	dsos__for_each_with_build_id(pos, head) {
 		int err;
@@ -197,10 +209,8 @@ static int __dsos__write_buildid_table(struct list_head *head, int fd)
 		err = do_write(fd, &b, sizeof(b));
 		if (err < 0)
 			return err;
-		err = do_write(fd, pos->long_name, pos->long_name_len + 1);
-		if (err < 0)
-			return err;
-		err = do_write(fd, zero_buf, len - pos->long_name_len - 1);
+		err = write_padded(fd, pos->long_name,
+				   pos->long_name_len + 1, len);
 		if (err < 0)
 			return err;
 	}