[PATCH] add NAME{ignore_remove} attribute

Some broken ide drivers are generating high event traffic, with
add/remove events. With this attribute, it can be specified,
that the node is always available. It may be used in conjunction
with the new DRIVER= match to catch specific kernel device drivers.

namedev.c

@@ -807,6 +807,7 @@ found:
 		goto done;
 
 	udev->partitions = dev->partitions;
+	udev->ignore_remove = dev->ignore_remove;
 
 	/* get permissions given in rule */
 	set_empty_perms(udev, dev->mode,

namedev.h

@@ -52,6 +52,7 @@ struct sysfs_class_device;
 #define FIELD_MODE		"MODE"
 
 #define ATTR_PARTITIONS		"all_partitions"
+#define ATTR_IGNORE_REMOVE	"ignore_remove"
 #define PARTITIONS_COUNT	15
 
 #define MAX_SYSFS_PAIRS		5
@@ -90,6 +91,7 @@ struct config_device {
 	char group[GROUP_SIZE];
 	unsigned int mode;
 	int partitions;
+	int ignore_remove;
 	char config_file[NAME_SIZE];
 	int config_line;
 };

namedev_parse.c

@@ -278,10 +278,16 @@ static int namedev_parse_rules(const char *filename, void *data)
 
 			if (strncasecmp(temp2, FIELD_NAME, sizeof(FIELD_NAME)-1) == 0) {
 				attr = get_key_attribute(temp2 + sizeof(FIELD_NAME)-1);
-				if (attr != NULL && strcasecmp(attr, ATTR_PARTITIONS) == 0) {
+				if (attr != NULL) {
+					if (strstr(attr, ATTR_PARTITIONS) != NULL) {
 						dbg_parse("creation of partition nodes requested");
 						dev.partitions = PARTITIONS_COUNT;
 					}
+					if (strstr(attr, ATTR_IGNORE_REMOVE) != NULL) {
+						dbg_parse("remove event should be ignored");
+						dev.ignore_remove = 1;
+					}
+				}
 				strfieldcpy(dev.name, temp3);
 				valid = 1;
 				continue;

test/udev-test.pl

@@ -1105,7 +1105,28 @@ KERNEL="sda", NAME="cdrom%e"
 EOF
 	},
 	{
-		desc		=> "SUBSYSTEM test",
+		desc		=> "ignore remove event test",
+		subsys		=> "block",
+		devpath		=> "/block/sda",
+		exp_name	=> "node",
+		exp_error	=> "yes",
+		conf		=> <<EOF
+BUS="scsi", KERNEL="sda", NAME{ignore_remove}="node"
+EOF
+	},
+	{
+		desc		=> "ignore remove event test (with all partitions)",
+		subsys		=> "block",
+		devpath		=> "/block/sda",
+		exp_name	=> "node14",
+		exp_error	=> "yes",
+		option		=> "clear",
+		conf		=> <<EOF
+BUS="scsi", KERNEL="sda", NAME{ignore_remove, all_partitions}="node"
+EOF
+	},
+	{
+		desc		=> "SUBSYSTEM match test",
 		subsys		=> "block",
 		devpath		=> "/block/sda",
 		exp_name	=> "node",
@@ -1116,7 +1137,7 @@ BUS="scsi", KERNEL="sda", NAME="should_not_match2", SUBSYSTEM="vc"
 EOF
 	},
 	{
-		desc		=> "DRIVER test",
+		desc		=> "DRIVER match test",
 		subsys		=> "block",
 		devpath		=> "/block/sda",
 		exp_name	=> "node",

udev.8.in

@@ -216,6 +216,13 @@ If given with the attribute
 .BR NAME{ all_partitions }
 it will  create all 15 partitions of a blockdevice.
 This may be useful for removable media devices.
+.br
+If given with the attribute
+.BR NAME{ ignore_remove }
+it will will ignore any later remove event for this device.
+This may be useful as a workaround for broken device drivers.
+.sp
+Multiple attributes may be separated by comma.
 .TP
 .B SYMLINK
 The name of a symlink targeting the node. Multiple symlinks may be

udev.h

@@ -57,6 +57,7 @@ struct udevice {
 	mode_t mode;
 	char symlink[NAME_SIZE];
 	int partitions;
+	int ignore_remove;
 	int config_line;
 	char config_file[NAME_SIZE];
 	long config_uptime;

udev_db.c

@@ -79,7 +79,8 @@ int udev_db_add_device(struct udevice *udev)
 	fprintf(f, "P:%s\n", udev->devpath);
 	fprintf(f, "N:%s\n", udev->name);
 	fprintf(f, "S:%s\n", udev->symlink);
-	fprintf(f, "A:%d\n", udev->partitions);
+	fprintf(f, "A:%u\n", udev->partitions);
+	fprintf(f, "R:%u\n", udev->ignore_remove);
 
 	fclose(f);
 
@@ -111,21 +112,34 @@ static int parse_db_file(struct udevice *udev, const char *filename)
 			if (count > DEVPATH_SIZE)
 				count = DEVPATH_SIZE-1;
 			strncpy(udev->devpath, &bufline[2], count-2);
+			udev->devpath[count-2] = '\0';
 			break;
 		case 'N':
 			if (count > NAME_SIZE)
 				count = NAME_SIZE-1;
 			strncpy(udev->name, &bufline[2], count-2);
+			udev->name[count-2] = '\0';
 			break;
 		case 'S':
 			if (count > NAME_SIZE)
 				count = NAME_SIZE-1;
 			strncpy(udev->symlink, &bufline[2], count-2);
+			udev->symlink[count-2] = '\0';
 			break;
 		case 'A':
-			strfieldcpy(line, &bufline[2]);
+			if (count > NAME_SIZE)
+				count = NAME_SIZE-1;
+			strncpy(line, &bufline[2], count-2);
+			line[count-2] = '\0';
 			udev->partitions = atoi(line);
 			break;
+		case 'R':
+			if (count > NAME_SIZE)
+				count = NAME_SIZE-1;
+			strncpy(line, &bufline[2], count-2);
+			line[count-2] = '\0';
+			udev->ignore_remove = atoi(line);
+			break;
 		}
 	}
 

udev_remove.c

@@ -185,6 +185,11 @@ int udev_remove_device(struct udevice *udev)
 		dbg("'%s' not found in database, falling back on default name", udev->name);
 	}
 
+	if (udev->ignore_remove) {
+		dbg("remove event for '%s' requested to be ignored by rule", udev->name);
+		return 0;
+	}
+
 	dbg("remove name='%s'", udev->name);
 	udev_db_delete_device(udev);