1 files changed, 30 insertions, 4 deletions

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 1e03bc89e20f..ac83f5002ce5 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -601,17 +601,27 @@ static void list_version_get_info(struct target_type *tt, void *param)
     info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
 }
 
-static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
+static int __list_versions(struct dm_ioctl *param, size_t param_size, const char *name)
 {
         size_t len, needed = 0;
         struct dm_target_versions *vers;
         struct vers_iter iter_info;
+        struct target_type *tt = NULL;
+
+        if (name) {
+                tt = dm_get_target_type(name);
+                if (!tt)
+                        return -EINVAL;
+        }
 
         /*
          * Loop through all the devices working out how much
          * space we need.
          */
-        dm_target_iterate(list_version_get_needed, &needed);
+        if (!tt)
+                dm_target_iterate(list_version_get_needed, &needed);
+        else
+                list_version_get_needed(tt, &needed);
 
         /*
          * Grab our output buffer.
@@ -632,13 +642,28 @@ static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param
         /*
          * Now loop through filling out the names & versions.
          */
-        dm_target_iterate(list_version_get_info, &iter_info);
+        if (!tt)
+                dm_target_iterate(list_version_get_info, &iter_info);
+        else
+                list_version_get_info(tt, &iter_info);
         param->flags |= iter_info.flags;
 
  out:
+        if (tt)
+                dm_put_target_type(tt);
         return 0;
 }
 
+static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
+{
+        return __list_versions(param, param_size, NULL);
+}
+
+static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t param_size)
+{
+        return __list_versions(param, param_size, param->name);
+}
+
 static int check_name(const char *name)
 {
         if (strchr(name, '/')) {
@@ -1592,7 +1617,7 @@ static int target_message(struct file *filp, struct dm_ioctl *param, size_t para
         }
 
         ti = dm_table_find_target(table, tmsg->sector);
-        if (!dm_target_is_valid(ti)) {
+        if (!ti) {
                 DMWARN("Target message sector outside device.");
                 r = -EINVAL;
         } else if (ti->type->message)
@@ -1664,6 +1689,7 @@ static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
                 {DM_TARGET_MSG_CMD, 0, target_message},
                 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry},
                 {DM_DEV_ARM_POLL, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
+                {DM_GET_TARGET_VERSION, 0, get_target_version},
         };
 
         if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))