fix magic sysrq file-open flags, change sync/ro order

1 files changed, 8 insertions, 5 deletions

diff --git a/instr-daemon.c b/instr-daemon.c
index 7b85636..5258362 100644
--- a/instr-daemon.c
+++ b/instr-daemon.c
@@ -331,20 +331,23 @@ static gboolean periodic_poll (void)
 		LCD_write(0,0,"Power failed. Shutdown.");
 
 		// use plain old open to avoid any buffering etc
-		int enablefd = open("/proc/sys/kernel/sysrq", O_SYNC, O_RDWR);
-		int trgfd = open("/proc/sysrq-trigger", O_SYNC, O_RDWR);
+		int enablefd = open("/proc/sys/kernel/sysrq", O_SYNC | O_RDWR);
+		int trgfd = open("/proc/sysrq-trigger", O_SYNC | O_RDWR);
 
 		// enable sysrq
 		write(enablefd, "1\n", 2);
-
-		// remount ro
-		write(trgfd, "u\n", 2);
+		close(enablefd);
 
 		// sync disks
 		write(trgfd, "s\n", 2);
 
+		// remount ro
+		write(trgfd, "u\n", 2);
+		close(trgfd);
+
 		// poweroff
 		system ("/usr/bin/systemctl poweroff -f");
+
 		exit(0);
 	}