From: Simon Schubert <corecode@dragonflybsd.org>
Date: Thu, 9 Jul 2009 12:37:16 +0000 (+0200)
Subject: dma: lock temp files on creation
X-Git-Tag: v2.4.0~414^2~25
X-Git-Url: http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/855166cab18c755f280c77646aea8d1295931627

dma: lock temp files on creation

Lock the temporary files after creating them to protect from a "dma -q"
run at just the wrong time causing a double delivery attempt for
the same message.

Submitted-by: Peter Pentchev <roam@ringlet.net>
---

diff --git a/libexec/dma/dma.c b/libexec/dma/dma.c
index 3ca9826..6599635 100644
--- a/libexec/dma/dma.c
+++ b/libexec/dma/dma.c
@@ -223,6 +223,8 @@ gentempf(struct queue *queue)
 	fd = mkstemp(fn);
 	if (fd < 0)
 		return (-1);
+	if (flock(fd, LOCK_EX) == -1)
+		return (-1);
 	queue->mailfd = fd;
 	queue->tmpf = strdup(fn);
 	if (queue->tmpf == NULL) {