udevtrigger: trigger devices sorted by their dependency

Resolve the links to the real device location in the tree, and
sort the list, to make sure that parent devices are triggered
before their childs.

1 files changed, 60 insertions, 89 deletions

diff --git a/udevtrigger.c b/udevtrigger.c
index bf5ec25aca..c5d88b9ee0 100644
--- a/udevtrigger.c
+++ b/udevtrigger.c
@@ -34,6 +34,14 @@
 #include "udev.h"
 #include "udevd.h"
 
+static int verbose;
+static int dry_run;
+LIST_HEAD(device_list);
+LIST_HEAD(filter_subsystem_match_list);
+LIST_HEAD(filter_subsystem_nomatch_list);
+LIST_HEAD(filter_attr_match_list);
+LIST_HEAD(filter_attr_nomatch_list);
+
 #ifdef USE_LOG
 void log_message(int priority, const char *format, ...)
 {
@@ -48,69 +56,62 @@ void log_message(int priority, const char *format, ...)
 }
 #endif
 
-static int verbose;
-static int dry_run;
-
-/* list of devices that we should run last due to any one of a number of reasons */
-static char *last_list[] = {
-	"/class/block/md",
-	"/class/block/dm-",
-	"/block/md",
-	"/block/dm-",
-	NULL
-};
-
-/* list of devices that we should run first due to any one of a number of reasons */
-static char *first_list[] = {
-	"/class/mem",
-	"/class/tty",
-	NULL
-};
-
-LIST_HEAD(device_first_list);
-LIST_HEAD(device_default_list);
-LIST_HEAD(device_last_list);
+/* devices that should run last cause of their dependencies */
+static int delay_device(const char *devpath)
+{
+	static const char *delay_device_list[] = {
+		"*/md*",
+		"*/dm-*",
+		NULL
+	};
+	int i;
 
-LIST_HEAD(filter_subsystem_match_list);
-LIST_HEAD(filter_subsystem_nomatch_list);
-LIST_HEAD(filter_attr_match_list);
-LIST_HEAD(filter_attr_nomatch_list);
+	for (i = 0; delay_device_list[i] != NULL; i++)
+		if (fnmatch(delay_device_list[i], devpath, 0) == 0)
+			return 1;
+	return 0;
+}
 
 static int device_list_insert(const char *path)
 {
-	struct list_head *device_list = &device_default_list;
-	const char *devpath = &path[strlen(sysfs_path)];
-	int i;
-
-	for (i = 0; first_list[i] != NULL; i++) {
-		if (strncmp(devpath, first_list[i], strlen(first_list[i])) == 0) {
-			device_list = &device_first_list;
-			break;
-		}
-	}
-	for (i = 0; last_list[i] != NULL; i++) {
-		if (strncmp(devpath, last_list[i], strlen(last_list[i])) == 0) {
-			device_list = &device_last_list;
-			break;
-		}
-	}
+	char filename[PATH_SIZE];
+	char devpath[PATH_SIZE];
+	struct stat statbuf;
 
 	dbg("add '%s'" , path);
-	/* double entries will be ignored */
-	name_list_add(device_list, path, 0);
+
+	/* we only have a device, if we have an uevent file */
+	strlcpy(filename, path, sizeof(filename));
+	strlcat(filename, "/uevent", sizeof(filename));
+	if (stat(filename, &statbuf) < 0)
+		return -1;
+	if (!(statbuf.st_mode & S_IWUSR))
+		return -1;
+
+	strlcpy(devpath, &path[strlen(sysfs_path)], sizeof(devpath));
+
+	/* resolve possible link to real target */
+	if (lstat(path, &statbuf) < 0)
+		return -1;
+	if (S_ISLNK(statbuf.st_mode))
+		if (sysfs_resolve_link(devpath, sizeof(devpath)) != 0)
+			return -1;
+
+	name_list_add(&device_list, devpath, 1);
 	return 0;
 }
 
-static void trigger_uevent(const char *path)
+static void trigger_uevent(const char *devpath)
 {
 	char filename[PATH_SIZE];
 	int fd;
 
-	strlcpy(filename, path, sizeof(filename));
+	strlcpy(filename, sysfs_path, sizeof(filename));
+	strlcat(filename, devpath, sizeof(filename));
 	strlcat(filename, "/uevent", sizeof(filename));
 
 	if (verbose)
-		printf("%s\n", path);
+		printf("%s\n", devpath);
 
 	if (dry_run)
 		return;
@@ -127,50 +128,28 @@ static void trigger_uevent(const char *path)
 	close(fd);
 }
 
-static void exec_lists(void)
+static void exec_list(void)
 {
 	struct name_entry *loop_device;
 	struct name_entry *tmp_device;
 
-	/* handle the devices on the "first" list first */
-	list_for_each_entry_safe(loop_device, tmp_device, &device_first_list, node) {
-		trigger_uevent(loop_device->name);
-		list_del(&loop_device->node);
-		free(loop_device);
-	}
+	list_for_each_entry_safe(loop_device, tmp_device, &device_list, node) {
+		if (delay_device(loop_device->name))
+			continue;
 
-	/* handle the devices on the "default" list next */
-	list_for_each_entry_safe(loop_device, tmp_device, &device_default_list, node) {
 		trigger_uevent(loop_device->name);
 		list_del(&loop_device->node);
 		free(loop_device);
 	}
 
-	/* handle devices on the "last" list, if any */
-	list_for_each_entry_safe(loop_device, tmp_device, &device_last_list, node) {
+	/* trigger remaining delayed devices */
+	list_for_each_entry_safe(loop_device, tmp_device, &device_list, node) {
 		trigger_uevent(loop_device->name);
 		list_del(&loop_device->node);
 		free(loop_device);
 	}
 }
 
-static int is_device(const char *path)
-{
-	char filename[PATH_SIZE];
-	struct stat statbuf;
-
-	/* look for the uevent file of the kobject */
-	strlcpy(filename, path, sizeof(filename));
-	strlcat(filename, "/uevent", sizeof(filename));
-	if (stat(filename, &statbuf) < 0)
-		return 0;
-
-	if (!(statbuf.st_mode & S_IWUSR))
-		return 0;
-
-	return 1;
-}
-
 static int subsystem_filtered(const char *subsystem)
 {
 	struct name_entry *loop_name;
@@ -299,8 +278,7 @@ static void scan_bus(void)
 					strlcat(dirname2, dent2->d_name, sizeof(dirname2));
 					if (attr_filtered(dirname2))
 						continue;
-					if (is_device(dirname2))
-						device_list_insert(dirname2);
+					device_list_insert(dirname2);
 				}
 				closedir(dir2);
 			}
@@ -343,9 +321,7 @@ static void scan_block(void)
 			strlcat(dirname, dent->d_name, sizeof(dirname));
 			if (attr_filtered(dirname))
 				continue;
-			if (is_device(dirname))
-				device_list_insert(dirname);
-			else
+			if (device_list_insert(dirname) != 0);
 				continue;
 
 			/* look for partitions */
@@ -365,8 +341,7 @@ static void scan_block(void)
 					strlcat(dirname2, dent2->d_name, sizeof(dirname2));
 					if (attr_filtered(dirname2))
 						continue;
-					if (is_device(dirname2))
-						device_list_insert(dirname2);
+					device_list_insert(dirname2);
 				}
 				closedir(dir2);
 			}
@@ -416,8 +391,7 @@ static void scan_class(void)
 					strlcat(dirname2, dent2->d_name, sizeof(dirname2));
 					if (attr_filtered(dirname2))
 						continue;
-					if (is_device(dirname2))
-						device_list_insert(dirname2);
+					device_list_insert(dirname2);
 				}
 				closedir(dir2);
 			}
@@ -455,10 +429,7 @@ static void scan_failed(void)
 				if (device[i] == PATH_TO_NAME_CHAR)
 					device[i] = '/';
 
-			if (is_device(device))
-				device_list_insert(device);
-			else
-				continue;
+			device_list_insert(device);
 		}
 		closedir(dir);
 	}
@@ -539,7 +510,7 @@ int main(int argc, char *argv[], char *envp[])
 		scan_class();
 		scan_block();
 	}
-	exec_lists();
+	exec_list();
 
 exit:
 	name_list_cleanup(&filter_subsystem_match_list);