From: Jens Axboe <axboe@suse.de>
Date: Fri, 7 Oct 2005 08:22:41 +0000 (+0200)
Subject: [PATCH] blktrace: fix error on stopping live trace and allow trace on CDROM
X-Git-Tag: blktrace-0.99~27
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=cf9208eac82ccd06074c026460d9bb256c2ea3a2;p=blktrace.git

[PATCH] blktrace: fix error on stopping live trace and allow trace on CDROM

We need O_NONBLOCK to trace on an empty CDROM device
---

diff --git a/blktrace.c b/blktrace.c
index 8d78a9b..48065d1 100644
--- a/blktrace.c
+++ b/blktrace.c
@@ -186,10 +186,13 @@ static int start_trace(struct device_information *dip)
 static void stop_trace(struct device_information *dip)
 {
 	if (dip->trace_started || kill_running_trace) {
+		dip->trace_started = 0;
+
 		if (ioctl(dip->fd, BLKSTOPTRACE) < 0)
 			perror("BLKSTOPTRACE");
+
 		close(dip->fd);
-		dip->trace_started = 0;
+		dip->fd = -1;
 	}
 }
 
@@ -550,7 +553,7 @@ static int open_devices(void)
 	int i;
 
 	for (dip = device_information, i = 0; i < ndevs; i++, dip++) {
-		dip->fd = open(dip->path, O_RDONLY);
+		dip->fd = open(dip->path, O_RDONLY | O_NONBLOCK);
 		if (dip->fd < 0) {
 			perror(dip->path);
 			return 1;