svn commit: r327187 - stable/11/usr.sbin/diskinfo

[Alan Somers]

Author: asomers
Date: Tue Dec 26 04:00:30 2017
New Revision: 327187
URL: https://svnweb.freebsd.org/changeset/base/327187

Log:
  MFC r326290:
  
  diskinfo(8): Delete dead code in slog test
  
  Reported by:	Coverity
  CID:		1377556
  Reviewed by:	mav
  Sponsored by:	Spectra Logic Corp
  Differential Revision:	https://reviews.freebsd.org/D13275

Modified:
  stable/11/usr.sbin/diskinfo/diskinfo.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/usr.sbin/diskinfo/diskinfo.c
==============================================================================
--- stable/11/usr.sbin/diskinfo/diskinfo.c	Tue Dec 26 03:59:49 2017	(r327186)
+++ stable/11/usr.sbin/diskinfo/diskinfo.c	Tue Dec 26 04:00:30 2017	(r327187)
@@ -644,22 +644,22 @@ 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");