From 4fbc637701094f8722f44f4461537be4d4d0d7d4 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 6 Oct 2012 01:41:07 +0300
Subject: [PATCH] Avoid checking the same device more than once

---
 main.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 87 insertions(+), 17 deletions(-)

diff --git a/main.c b/main.c
index 910983f..ee55972 100644
--- a/main.c
+++ b/main.c
@@ -208,31 +208,99 @@ void free_mounted_devices(char **mounted)
 	free(mounted);
 }
 
-Device *get_devices(void)
+char **get_device_nodes(char *dirname)
 {
 	DIR *dir;
 	struct dirent *de;
 	char fnbuf[256];
-	Device *devices = NULL;
-	int n_devices = 0;
-	char **mounted = NULL;
-	
-	dir = opendir("/dev/disk/by-id");
+	char linkbuf[256];
+	struct stat st;
+	char **nodes = NULL;
+	int n_nodes = 0;
+	char **checked = NULL;
+	int n_checked = 0;
+	int i;
+
+	dir = opendir(dirname);
 	if(!dir)
 		return NULL;
 
-	mounted = get_mounted_devices();
-
 	while((de = readdir(dir)))
 	{
+		char *node;
+		int duplicate = 0;
+
 		if(de->d_name[0]=='.' && (de->d_name[1]==0 || (de->d_name[1]=='.' && de->d_name[2]==0)))
 			continue;
 
-		snprintf(fnbuf, sizeof(fnbuf), "/dev/disk/by-id/%s", de->d_name);
+		snprintf(fnbuf, sizeof(fnbuf), "%s/%s", dirname, de->d_name);
+
+		node = fnbuf;
+		lstat(fnbuf, &st);
+		if(S_ISLNK(st.st_mode))
+		{
+			int len;
+			len = readlink(fnbuf, linkbuf, sizeof(linkbuf)-1);
+			if(len!=-1)
+			{
+				linkbuf[len] = 0;
+				node = linkbuf;
+			}
+		}
+
+		if(checked)
+		{
+			for(i=0; (!duplicate && i<n_checked); ++i)
+				if(strcmp(node, checked[i])==0)
+					duplicate = 1;
+		}
+		if(duplicate)
+		{
+			if(verbosity>=1)
+				printf("Device %s is a duplicate\n", fnbuf);
+			continue;
+		}
+
+		checked = (char **)realloc(checked, (n_checked+1)*sizeof(char *));
+		checked[n_checked] = strdup(node);
+		++n_checked;
+
+		nodes = (char **)realloc(nodes, (n_nodes+2)*sizeof(char *));
+		nodes[n_nodes] = strdup(fnbuf);
+		++n_nodes;
+	}
+
+	closedir(dir);
+	if(checked)
+	{
+		for(i=0; i<n_checked; ++i)
+			free(checked[i]);
+		free(checked);
+	}
+
+	if(nodes)
+		nodes[n_nodes] = NULL;
+
+	return nodes;
+}
+
+Device *get_devices(void)
+{
+	char **nodes = NULL;
+	Device *devices = NULL;
+	int n_devices = 0;
+	char **mounted = NULL;
+	int i;
+
+	nodes = get_device_nodes("/dev/disk/by-id");
+	mounted = get_mounted_devices();
+
+	for(i=0; nodes[i]; ++i)
+	{
 		if(verbosity>=1)
-			printf("Examining device %s\n", fnbuf);
+			printf("Examining device %s\n", nodes[i]);
 
-		Property *props = get_device_properties(fnbuf);
+		Property *props = get_device_properties(nodes[i]);
 		if(!props)
 		{
 			if(verbosity>=2)
@@ -242,9 +310,9 @@ Device *get_devices(void)
 
 		if(verbosity>=2)
 		{
-			int i;
-			for(i=0; props[i].name; ++i)
-				printf("  %s = %s\n", props[i].name, props[i].value);
+			int j;
+			for(j=0; props[j].name; ++j)
+				printf("  %s = %s\n", props[j].name, props[j].value);
 		}
 
 		if(match_property_value(props, "ID_BUS", "usb") && match_property_value(props, "DEVTYPE", "partition"))
@@ -282,20 +350,22 @@ Device *get_devices(void)
 			if(vendor && model)
 				pos += snprintf(buf+pos, sizeof(buf)-pos, " (%s %s)", vendor, model);
 
-			stat(fnbuf, &st);
+			stat(nodes[i], &st);
 
 			devices = (Device *)realloc(devices, (n_devices+2)*sizeof(Device));
-			devices[n_devices].node = strdup(fnbuf);
+			devices[n_devices].node = nodes[i];
 			devices[n_devices].label = strdup(label);
 			devices[n_devices].description = strdup(buf);
 			devices[n_devices].mounted = is_mounted(mounted, devname);
 			devices[n_devices].time = st.st_mtime;
 			++n_devices;
 		}
+		else
+			free(nodes[i]);
 		free_properties(props);
 	}
 
-	closedir(dir);
+	free(nodes);
 	free_mounted_devices(mounted);
 
 	if(devices)
-- 
2.45.2