Add features to get table/status & wait for next event.

libdm/ioctl/libdevmapper.c

@@ -35,9 +35,20 @@ static char *dm_cmd_list[] = {
 	"info",
 	"deps",
 	"rename",
-	"version"
+	"version",
+	"status",
+	"table",
+	"waitevent"
 };
 
+
+static void *_align(void *ptr, unsigned int a)
+{
+	register unsigned long align = --a;
+
+	return (void *) (((unsigned long) ptr + align) & ~align);
+}
+
 void dm_task_destroy(struct dm_task *dmt)
 {
 	struct target *t, *n;
@@ -74,6 +85,49 @@ int dm_task_get_driver_version(struct dm_task *dmt, char *version, size_t size)
 	return 1;
 }
 
+void *dm_get_next_target(struct dm_task *dmt, void *next, unsigned long long *start,
+			 unsigned long long *length,
+			 char **target_type,
+			 char **params)
+{
+    struct target *t;
+
+    if (!next)
+	next = dmt->head;
+
+    t = next;
+
+    if (t) {
+
+	*start = t->start;
+	*length = t->length;
+	*target_type = t->type;
+	*params = t->params;
+	return t->next;
+    }
+    return NULL;
+}
+
+/* Unmarshall the target info returned from a status call */
+static int unmarshal_status(struct dm_task *dmt, struct dm_ioctl *dmi)
+{
+        char *outbuf = (char *)dmi + sizeof(struct dm_ioctl);
+	char *outptr = outbuf;
+	int i;
+
+	for (i=0; i < dmi->target_count; i++) {
+	    struct dm_target_spec *spec = (struct dm_target_spec *)outptr;
+
+	    if (!dm_task_add_target(dmt, spec->sector_start, spec->length,
+				    spec->target_type, outptr+sizeof(*spec)))
+		return 0;
+	    outptr += sizeof(struct dm_target_spec);
+	    outptr += strlen(outptr) + 1;
+	    _align(outptr, ALIGNMENT);
+	}
+	return 1;
+}
+
 int dm_task_get_info(struct dm_task *dmt, struct dm_info *info)
 {
 	if (!dmt->dmi)
@@ -154,13 +208,6 @@ struct target *create_target(uint64_t start,
 	return NULL;
 }
 
-static void *_align(void *ptr, unsigned int a)
-{
-	register unsigned long align = --a;
-
-	return (void *) (((unsigned long) ptr + align) & ~align);
-}
-
 static void *_add_target(struct target *t, void *out, void *end)
 {
 	void *out_sp = out;
@@ -334,6 +381,19 @@ int dm_task_run(struct dm_task *dmt)
 		command = DM_VERSION;
 		break;
 
+	case DM_DEVICE_STATUS:
+		command = DM_GET_STATUS;
+		break;
+
+	case DM_DEVICE_TABLE:
+	        dmi->flags |= DM_STATUS_TABLE_FLAG;
+		command = DM_GET_STATUS;
+		break;
+
+	case DM_DEVICE_WAITEVENT:
+	        command = DM_WAIT_EVENT;
+		break;
+
 	default:
 		log_error("Internal error: unknown device-mapper task %d",
 			  dmt->type);
@@ -360,6 +420,12 @@ int dm_task_run(struct dm_task *dmt)
 	case DM_DEVICE_RENAME:
 		rename_dev_node(dmt->dev_name, dmt->newname);
 		break;
+
+	case DM_DEVICE_STATUS:
+	case DM_DEVICE_TABLE:
+	        if (!unmarshal_status(dmt, dmi))
+		        goto bad;
+	        break;
 	}
 
 	dmt->dmi = dmi;

libdm/libdevmapper.h

@@ -44,6 +44,10 @@ enum {
 	DM_DEVICE_RENAME,
 
 	DM_DEVICE_VERSION,
+
+	DM_DEVICE_STATUS,
+	DM_DEVICE_TABLE,
+	DM_DEVICE_WAITEVENT
 };
 
 struct dm_task;
@@ -91,6 +95,13 @@ int dm_task_add_target(struct dm_task *dmt,
 		       uint64_t start,
 		       uint64_t size, const char *ttype, const char *params);
 
+/* Use this to retrive target information returned from a STATUS call */
+void *dm_get_next_target(struct dm_task *dmt,
+			 void *next, unsigned long long *start,
+			 unsigned long long *length,
+			 char **target_type,
+			 char **params);
+
 /*
  * Call this to actually run the ioctl.
  */

tools/dmsetup.c

@@ -227,6 +227,67 @@ static int _resume(int argc, char **argv)
 	return _simple(DM_DEVICE_RESUME, argv[1]);
 }
 
+static int _wait(int argc, char **argv)
+{
+	struct dm_task *dmt;
+
+        if (!(dmt = dm_task_create(DM_DEVICE_WAITEVENT)))
+		return 0;
+
+	if (!dm_task_set_name(dmt, argv[1]))
+		goto out;
+
+	if (!dm_task_run(dmt))
+		goto out;
+
+	dm_task_destroy(dmt);
+
+ out:
+	return 1;
+}
+
+static int _status(int argc, char **argv)
+{
+	int r = 0;
+	struct dm_task *dmt;
+	void *next = NULL;
+	unsigned long long start, length;
+	char *target_type = NULL;
+	char *params;
+	int cmd;
+
+	if (strcmp(argv[0], "status") == 0)
+	    cmd = DM_DEVICE_STATUS;
+	else
+	    cmd = DM_DEVICE_TABLE;
+
+	if (!(dmt = dm_task_create(cmd)))
+		return 0;
+
+	if (!dm_task_set_name(dmt, argv[1]))
+		goto out;
+
+	if (!dm_task_run(dmt))
+		goto out;
+
+	/* Fetch targets and print 'em */
+	do {
+	    next = dm_get_next_target(dmt, next, &start, &length,
+				      &target_type, &params);
+	    if (target_type) {
+		printf("%lld %lld %s %s\n",
+		       start, length, target_type, params);
+	    }
+	} while (next);
+
+	r = 1;
+
+      out:
+	dm_task_destroy(dmt);
+	return r;
+
+}
+
 static int _info(int argc, char **argv)
 {
 	int r = 0;
@@ -345,6 +406,9 @@ static struct command _commands[] = {
 	{"info", "<dev_name>", 1, 1, _info},
 	{"deps", "<dev_name>", 1, 1, _deps},
 	{"rename", "<dev_name> <new_name>", 2, 2, _rename},
+	{"status", "<dev_name>", 1, 1, _status},
+	{"table", "<dev_name>", 1, 1, _status},
+	{"wait", "<dev_name>", 1, 1, _wait},
 	{"version", "", 0, 0, _version},
 	{NULL, NULL, 0, 0, NULL}
 };