add TAG= to improve event filtering and device enumeration

6 files changed, 62 insertions, 3 deletions

diff --git a/udev/udev-event.c b/udev/udev-event.c
index b2e1baee1f..212ccc7950 100644
--- a/udev/udev-event.c
+++ b/udev/udev-event.c
@@ -543,7 +543,6 @@ int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules)
 
 	if (strcmp(udev_device_get_action(dev), "remove") == 0) {
 		udev_device_read_db(dev);
-		udev_device_set_info_loaded(dev);
 		udev_device_delete_db(dev);
 
 		if (major(udev_device_get_devnum(dev)) != 0)
diff --git a/udev/udev-rules.c b/udev/udev-rules.c
index 6eb8350343..b5016d0bc3 100644
--- a/udev/udev-rules.c
+++ b/udev/udev-rules.c
@@ -157,6 +157,7 @@ enum token_type {
 	TK_A_GROUP_ID,			/* gid_t */
 	TK_A_MODE_ID,			/* mode_t */
 	TK_A_ENV,			/* val, attr */
+	TK_A_TAG,			/* val */
 	TK_A_NAME,			/* val */
 	TK_A_DEVLINK,			/* val */
 	TK_A_EVENT_TIMEOUT,		/* int */
@@ -285,6 +286,7 @@ static const char *token_str(enum token_type type)
 		[TK_A_GROUP_ID] =		"A GROUP_ID",
 		[TK_A_MODE_ID] =		"A MODE_ID",
 		[TK_A_ENV] =			"A ENV",
+		[TK_A_TAG] =			"A ENV",
 		[TK_A_NAME] =			"A NAME",
 		[TK_A_DEVLINK] =		"A DEVLINK",
 		[TK_A_EVENT_TIMEOUT] =		"A EVENT_TIMEOUT",
@@ -354,6 +356,9 @@ static void dump_token(struct udev_rules *rules, struct token *token)
 		dbg(rules->udev, "%s %s '%s' '%s'(%s)\n",
 		    token_str(type), operation_str(op), attr, value, string_glob_str(glob));
 		break;
+	case TK_A_TAG:
+		dbg(rules->udev, "%s %s '%s'\n", token_str(type), operation_str(op), value);
+		break;
 	case TK_A_STRING_ESCAPE_NONE:
 	case TK_A_STRING_ESCAPE_REPLACE:
 		dbg(rules->udev, "%s\n", token_str(type));
@@ -1003,6 +1008,7 @@ static int rule_add_key(struct rule_tmp *rule_tmp, enum token_type type,
 	case TK_A_MODE:
 	case TK_A_NAME:
 	case TK_A_GOTO:
+	case TK_A_TAG:
 		token->key.value_off = add_string(rule_tmp->rules, value);
 		break;
 	case TK_M_ENV:
@@ -1350,6 +1356,11 @@ static int add_rule(struct udev_rules *rules, char *line,
 			continue;
 		}
 
+		if (strcmp(key, "TAG") == 0) {
+			rule_add_key(&rule_tmp, TK_A_TAG, op, value, NULL);
+			continue;
+		}
+
 		if (strcmp(key, "PROGRAM") == 0) {
 			rule_add_key(&rule_tmp, TK_M_PROGRAM, op, value, NULL);
 			continue;
@@ -2408,6 +2419,9 @@ int udev_rules_apply_to_event(struct udev_rules *rules, struct udev_event *event
 				}
 				break;
 			}
+		case TK_A_TAG:
+			udev_device_add_tag(event->dev, &rules->buf[cur->key.value_off]);
+			break;
 		case TK_A_NAME:
 			{
 				const char *name  = &rules->buf[cur->key.value_off];
diff --git a/udev/udev.xml b/udev/udev.xml
index 192a6f1238..842fd5d52a 100644
--- a/udev/udev.xml
+++ b/udev/udev.xml
@@ -349,6 +349,19 @@
             </varlistentry>
 
             <varlistentry>
+              <term><option>TAG</option></term>
+              <listitem>
+                <para>Attach a tag to a device. This is used to filter events for users
+                of libudev's monitor functionality, or to enumerate a group of tagged
+                devices. The implementation can only work efficiently if only a few
+                tags are attached to a device. It is only meant to be used in
+                contexts with specific device filter requirements, and not as a
+                general-purpose flag. Excessive use might result in inefficient event
+                handling.</para>
+              </listitem>
+            </varlistentry>
+
+            <varlistentry>
               <term><option>RUN</option></term>
               <listitem>
                 <para>Add a program to the list of programs to be executed for a specific
diff --git a/udev/udevadm-monitor.c b/udev/udevadm-monitor.c
index d136c6070a..fb650846bc 100644
--- a/udev/udevadm-monitor.c
+++ b/udev/udevadm-monitor.c
@@ -73,6 +73,7 @@ int udevadm_monitor(struct udev *udev, int argc, char *argv[])
 	int print_kernel = 0;
 	int print_udev = 0;
 	struct udev_list_node subsystem_match_list;
+	struct udev_list_node tag_match_list;
 	struct udev_monitor *udev_monitor = NULL;
 	struct udev_monitor *kernel_monitor = NULL;
 	fd_set readfds;
@@ -84,13 +85,15 @@ int udevadm_monitor(struct udev *udev, int argc, char *argv[])
 		{ "kernel", no_argument, NULL, 'k' },
 		{ "udev", no_argument, NULL, 'u' },
 		{ "subsystem-match", required_argument, NULL, 's' },
+		{ "tag-match", required_argument, NULL, 't' },
 		{ "help", no_argument, NULL, 'h' },
 		{}
 	};
 
 	udev_list_init(&subsystem_match_list);
+	udev_list_init(&tag_match_list);
 	while (1) {
-		option = getopt_long(argc, argv, "epkus:h", options, NULL);
+		option = getopt_long(argc, argv, "pekus:t:h", options, NULL);
 		if (option == -1)
 			break;
 
@@ -119,12 +122,16 @@ int udevadm_monitor(struct udev *udev, int argc, char *argv[])
 				udev_list_entry_add(udev, &subsystem_match_list, subsys, devtype, 0, 0);
 				break;
 			}
+		case 't':
+			udev_list_entry_add(udev, &tag_match_list, optarg, NULL, 0, 0);
+			break;
 		case 'h':
 			printf("Usage: udevadm monitor [--property] [--kernel] [--udev] [--help]\n"
 			       "  --property                              print the event properties\n"
 			       "  --kernel                                print kernel uevents\n"
 			       "  --udev                                  print udev events\n"
 			       "  --subsystem-match=<subsystem[/devtype]> filter events by subsystem\n"
+			       "  --tag-match=<tag>                       filter events by tag\n"
 			       "  --help\n\n");
 		default:
 			goto out;
@@ -168,6 +175,13 @@ int udevadm_monitor(struct udev *udev, int argc, char *argv[])
 				fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys);
 		}
 
+		udev_list_entry_foreach(entry, udev_list_get_entry(&tag_match_list)) {
+			const char *tag = udev_list_entry_get_name(entry);
+
+			if (udev_monitor_filter_add_match_tag(udev_monitor, tag) < 0)
+				fprintf(stderr, "error: unable to apply tag filter '%s'\n", tag);
+		}
+
 		if (udev_monitor_enable_receiving(udev_monitor) < 0) {
 			fprintf(stderr, "error: unable to subscribe to udev events\n");
 			rc = 2;
@@ -244,5 +258,6 @@ out:
 	udev_monitor_unref(udev_monitor);
 	udev_monitor_unref(kernel_monitor);
 	udev_list_cleanup_entries(udev, &subsystem_match_list);
+	udev_list_cleanup_entries(udev, &tag_match_list);
 	return rc;
 }
diff --git a/udev/udevadm-trigger.c b/udev/udevadm-trigger.c
index 03aa53437f..3cb07dda9a 100644
--- a/udev/udevadm-trigger.c
+++ b/udev/udevadm-trigger.c
@@ -101,6 +101,7 @@ int udevadm_trigger(struct udev *udev, int argc, char *argv[])
 		{ "attr-match", required_argument, NULL, 'a' },
 		{ "attr-nomatch", required_argument, NULL, 'A' },
 		{ "property-match", required_argument, NULL, 'p' },
+		{ "tag-match", required_argument, NULL, 'g' },
 		{ "sysname-match", required_argument, NULL, 'y' },
 		{ "help", no_argument, NULL, 'h' },
 		{}
@@ -127,7 +128,7 @@ int udevadm_trigger(struct udev *udev, int argc, char *argv[])
 		const char *val;
 		char buf[UTIL_PATH_SIZE];
 
-		option = getopt_long(argc, argv, "vnFo:t:hcp:s:S:a:A:y:", options, NULL);
+		option = getopt_long(argc, argv, "vng:o:t:hcp:s:S:a:A:y:", options, NULL);
 		if (option == -1)
 			break;
 
@@ -172,6 +173,9 @@ int udevadm_trigger(struct udev *udev, int argc, char *argv[])
 			key = keyval(optarg, &val, buf, sizeof(buf));
 			udev_enumerate_add_match_property(udev_enumerate, key, val);
 			break;
+		case 'g':
+			udev_enumerate_add_match_tag(udev_enumerate, optarg);
+			break;
 		case 'y':
 			udev_enumerate_add_match_sysname(udev_enumerate, optarg);
 			break;
@@ -190,6 +194,7 @@ int udevadm_trigger(struct udev *udev, int argc, char *argv[])
 			       "  --attr-match=<file[=<value>]>   trigger devices with a matching attribute\n"
 			       "  --attr-nomatch=<file[=<value>]> exclude devices with a matching attribute\n"
 			       "  --property-match=<key>=<value>  trigger devices with a matching property\n"
+			       "  --tag-match=<key>=<value>       trigger devices with a matching property\n"
 			       "  --sysname-match=<name>          trigger devices with a matching name\n"
 			       "  --help\n\n");
 			goto exit;
diff --git a/udev/udevadm.xml b/udev/udevadm.xml
index fa1742bada..73e6f110a6 100644
--- a/udev/udevadm.xml
+++ b/udev/udevadm.xml
@@ -217,6 +217,13 @@
               </listitem>
             </varlistentry>
             <varlistentry>
+              <term><option>--tag-match=<replaceable>property</replaceable></option></term>
+              <listitem>
+                <para>Trigger events for devices with a matching tag. This option can be
+                specified multiple times.</para>
+              </listitem>
+            </varlistentry>
+            <varlistentry>
               <term><option>--sysname-match=<replaceable>name</replaceable></option></term>
               <listitem>
                 <para>Trigger events for devices with a matching sys device name. This option can be
@@ -356,6 +363,12 @@
               </listitem>
             </varlistentry>
             <varlistentry>
+              <term><option>--tag-match=<replaceable>string</replaceable></option></term>
+              <listitem>
+                <para>Filter events by property. Only udev events with a given tag attached will pass.</para>
+              </listitem>
+            </varlistentry>
+            <varlistentry>
               <term><option>--help</option></term>
               <listitem>
                 <para>Print help text.</para>