From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 29 Aug 2015 16:19:56 +0000 (+0300)
Subject: Generate a unique mount point name
X-Git-Url: http://git.tdb.fi/?p=pmount-gui.git;a=commitdiff_plain;h=0a8aff086f409621047d9dd62ffee7ae0a819c96

Generate a unique mount point name

It may happen that two devices have the same label.
---

diff --git a/main.c b/main.c
index e5b6440..5aa9611 100644
--- a/main.c
+++ b/main.c
@@ -7,6 +7,7 @@
 #include <fcntl.h>
 #include <dirent.h>
 #include <mntent.h>
+#include <errno.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
 #include <sys/select.h>
@@ -635,19 +636,38 @@ int toggle_device(Device *device, char *out_buf, int out_size)
 {
 	int umount = !!device->mount_point;
 	char mount_point[1024];
-	int len;
 	int pos = 0;
 	int status = 0;
 	fd_set fds;
 	struct timeval timeout;
 	int pid;
 	int pipe_fd[2];
+	char suffix = 0;
 
 	out_buf[0] = 0;
 
-	len = snprintf(mount_point, sizeof(mount_point), "/media/%s", device->label);
-	if(len>=(int)sizeof(mount_point))
-		return -1;
+	/* Find a mount point that does not exist yet. */
+	while(1)
+	{
+		int len;
+
+		len = snprintf(mount_point, sizeof(mount_point), "/media/%s", device->label);
+		if(len+2>=(int)sizeof(mount_point))
+			return -1;
+
+		if(suffix)
+			len += snprintf(mount_point+len, sizeof(mount_point)-len, "_%c", suffix);
+
+		if(access(mount_point, F_OK)<0 && errno==ENOENT)
+			break;
+
+		if(suffix==0)
+			suffix = '1';
+		else if(suffix<'9')
+			++suffix;
+		else
+			return -1;
+	}
 
 	pipe(pipe_fd);