From 6198a4102c5b171604b1ee82bd4a513be5506ab3 Mon Sep 17 00:00:00 2001
From: Alasdair Kergon <agk@redhat.com>
Date: Tue, 15 Jan 2002 15:21:57 +0000
Subject: [PATCH] Another ioctl interface update:   Supply offset to start of
 variable data area (so struct size can change without breaking backward
 compatibility)   Add command that just returns the driver version

---
 libdm/ioctl/libdevmapper.c | 33 +++++++++++++++++++++++++--------
 libdm/libdevmapper.h       |  4 ++++
 tools/dmsetup.c            | 29 ++++++++++++++++++++++++++++-
 3 files changed, 57 insertions(+), 9 deletions(-)

diff --git a/libdm/ioctl/libdevmapper.c b/libdm/ioctl/libdevmapper.c
index 5e31cbf53..aaac6e278 100644
--- a/libdm/ioctl/libdevmapper.c
+++ b/libdm/ioctl/libdevmapper.c
@@ -13,7 +13,6 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/stat.h>
-#include <sys/types.h>
 #include <errno.h>
 #include <linux/kdev_t.h>
 
@@ -44,6 +43,17 @@ void dm_task_destroy(struct dm_task *dmt)
 	free(dmt);
 }
 
+int dm_task_get_driver_version(struct dm_task *dmt, char *version, 
+			       size_t size)
+{
+	if (!dmt->dmi)
+		return 0;
+
+	strncpy(version, dmt->dmi->version, size);
+
+	return 1;
+}
+
 int dm_task_get_info(struct dm_task *dmt, struct dm_info *info)
 {
 	if (!dmt->dmi)
@@ -51,12 +61,12 @@ int dm_task_get_info(struct dm_task *dmt, struct dm_info *info)
 
 	memset(info, 0, sizeof(*info));
 
-	info->exists = dmt->dmi->status & DM_EXISTS_FLAG ? 1 : 0;
+	info->exists = dmt->dmi->flags & DM_EXISTS_FLAG ? 1 : 0;
 	if (!info->exists)
 		return 1;
 
-	info->suspended = dmt->dmi->status & DM_SUSPEND_FLAG ? 1 : 0;
-	info->read_only = dmt->dmi->status & DM_READONLY_FLAG ? 1 : 0;
+	info->suspended = dmt->dmi->flags & DM_SUSPEND_FLAG ? 1 : 0;
+	info->read_only = dmt->dmi->flags & DM_READONLY_FLAG ? 1 : 0;
 	info->target_count = dmt->dmi->target_count;
 	info->open_count = dmt->dmi->open_count;
 	info->major = MAJOR(dmt->dmi->dev);
@@ -188,15 +198,18 @@ static struct dm_ioctl *_flatten(struct dm_task *dmt)
 
 	strncpy(dmi->version, DM_IOCTL_VERSION, sizeof(dmi->version));
 	dmi->data_size = len;
-	strncpy(dmi->name, dmt->dev_name, sizeof(dmi->name));
+	dmi->data_start = sizeof(struct dm_ioctl);
+
+	if (dmt->dev_name)
+		strncpy(dmi->name, dmt->dev_name, sizeof(dmi->name));
 
 	if (dmt->type == DM_DEVICE_SUSPEND)
-		dmi->status |= DM_SUSPEND_FLAG;
+		dmi->flags |= DM_SUSPEND_FLAG;
 	if (dmt->read_only)
-		dmi->status |= DM_READONLY_FLAG;
+		dmi->flags |= DM_READONLY_FLAG;
 
 	if (dmt->minor > 0) {
-		dmi->status |= DM_PERSISTENT_DEV_FLAG;
+		dmi->flags |= DM_PERSISTENT_DEV_FLAG;
 		dmi->dev = MKDEV(0, dmt->minor);
 	}
 
@@ -267,6 +280,10 @@ int dm_task_run(struct dm_task *dmt)
 		command = DM_RENAME;
 		break;
 
+	case DM_DEVICE_VERSION:
+		command = DM_VERSION;
+		break;
+
 	default:
 		log("Internal error: unknown device-mapper task %d",
 		    dmt->type);
diff --git a/libdm/libdevmapper.h b/libdm/libdevmapper.h
index 7e3cf61c9..1e5076c5b 100644
--- a/libdm/libdevmapper.h
+++ b/libdm/libdevmapper.h
@@ -8,6 +8,7 @@
 #define LIB_DEVICE_MAPPER_H
 
 #include <inttypes.h>
+#include <sys/types.h>
 
 /*
  * Since it is quite laborious to build the ioctl
@@ -39,6 +40,8 @@ enum {
 
 	DM_DEVICE_INFO,
 	DM_DEVICE_RENAME,
+
+	DM_DEVICE_VERSION,
 };
 
 
@@ -63,6 +66,7 @@ struct dm_info {
 	unsigned int target_count;
 };
 
+int dm_task_get_driver_version(struct dm_task *dmt, char *version, size_t size);
 int dm_task_get_info(struct dm_task *dmt, struct dm_info *dmi);
 
 int dm_task_set_ro(struct dm_task *dmt);
diff --git a/tools/dmsetup.c b/tools/dmsetup.c
index a7328fbbb..4f1687d57 100644
--- a/tools/dmsetup.c
+++ b/tools/dmsetup.c
@@ -156,6 +156,32 @@ out:
         return r;
 }
 
+static int _version(int argc, char **argv)
+{
+	int r = 0;
+	struct dm_task *dmt;
+	char version[16];
+
+	if (!(dmt = dm_task_create(DM_DEVICE_VERSION)))
+		return 0;
+
+	if (!dm_task_run(dmt))
+		goto out;
+
+	if (!dm_task_get_driver_version(dmt, (char *)&version, 
+					sizeof(version)))
+		goto out;
+
+	printf("Driver version:    %s\n", version);
+
+	r = 1;
+
+      out:
+	dm_task_destroy(dmt);
+
+	return r;
+}
+
 static int _simple(int task, const char *name)
 {
 	int r = 0;
@@ -256,6 +282,7 @@ static struct command _commands[] = {
 	{"reload", "<dev_name> <table_file>", 2, _reload},
 	{"info", "<dev_name>", 1, _info},
 	{"rename", "<dev_name> <new_name>", 2, _rename},
+	{"version", "", 0, _version},
 	{NULL, NULL, 0, NULL}
 };
 
@@ -322,7 +349,7 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 
-	if (argc < 2) {
+	if (argc == 0) {
 		_usage(stderr);
 		exit(1);
 	}