1 files changed, 13 insertions, 5 deletions

diff --git a/include/linux/dm-log-userspace.h b/include/linux/dm-log-userspace.h
index eeace7d3ff15..0678c2adc421 100644
--- a/include/linux/dm-log-userspace.h
+++ b/include/linux/dm-log-userspace.h
@@ -52,15 +52,20 @@
  * Payload-to-userspace:
  *      A single string containing all the argv arguments separated by ' 's
  * Payload-to-kernel:
- *      None.  ('data_size' in the dm_ulog_request struct should be 0.)
+ *      A NUL-terminated string that is the name of the device that is used
+ *      as the backing store for the log data.  'dm_get_device' will be called
+ *      on this device.  ('dm_put_device' will be called on this device
+ *      automatically after calling DM_ULOG_DTR.)  If there is no device needed
+ *      for log data, 'data_size' in the dm_ulog_request struct should be 0.
  *
  * The UUID contained in the dm_ulog_request structure is the reference that
  * will be used by all request types to a specific log.  The constructor must
- * record this assotiation with instance created.
+ * record this association with the instance created.
  *
  * When the request has been processed, user-space must return the
- * dm_ulog_request to the kernel - setting the 'error' field and
- * 'data_size' appropriately.
+ * dm_ulog_request to the kernel - setting the 'error' field, filling the
+ * data field with the log device if necessary, and setting 'data_size'
+ * appropriately.
  */
 #define DM_ULOG_CTR                    1
 
@@ -377,8 +382,11 @@
  * dm_ulog_request or a change in the way requests are
  * issued/handled.  Changes are outlined here:
  *      version 1:  Initial implementation
+ *      version 2:  DM_ULOG_CTR allowed to return a string containing a
+ *                  device name that is to be registered with DM via
+ *                  'dm_get_device'.
  */
-#define DM_ULOG_REQUEST_VERSION 1
+#define DM_ULOG_REQUEST_VERSION 2
 
 struct dm_ulog_request {
         /*