From 18e980c0e05ef128446723f7fc96e8dc864df088 Mon Sep 17 00:00:00 2001
From: Alan Somers <asomers@FreeBSD.org>
Date: Mon, 27 Nov 2017 21:10:50 +0000
Subject: [PATCH] diskinfo(8): Delete dead code in slog test

Reported by:	Coverity
CID:		1377556
Reviewed by:	mav
MFC after:	3 weeks
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D13275
---
 usr.sbin/diskinfo/diskinfo.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/usr.sbin/diskinfo/diskinfo.c b/usr.sbin/diskinfo/diskinfo.c
index a6769621b61a..00dd96880242 100644
--- a/usr.sbin/diskinfo/diskinfo.c
+++ b/usr.sbin/diskinfo/diskinfo.c
@@ -646,22 +646,22 @@ parwrite(int fd, size_t size, off_t off)
 {
 	struct aiocb aios[MAXIOS];
 	off_t o;
-	size_t s;
 	int n, error;
 	struct aiocb *aiop;
 
-	for (n = 0, o = 0; size > MAXIO; n++, size -= s, o += s) {
-		s = (size >= MAXIO) ? MAXIO : size;
+	// if size > MAXIO, use AIO to write n - 1 pieces in parallel
+	for (n = 0, o = 0; size > MAXIO; n++, size -= MAXIO, o += MAXIO) {
 		aiop = &aios[n];
 		bzero(aiop, sizeof(*aiop));
 		aiop->aio_buf = &buf[o];
 		aiop->aio_fildes = fd;
 		aiop->aio_offset = off + o;
-		aiop->aio_nbytes = s;
+		aiop->aio_nbytes = MAXIO;
 		error = aio_write(aiop);
 		if (error != 0)
 			err(EX_IOERR, "AIO write submit error");
 	}
+	// Use synchronous writes for the runt of size <= MAXIO
 	error = pwrite(fd, &buf[o], size, off + o);
 	if (error < 0)
 		err(EX_IOERR, "Sync write error");