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Diffstat (limited to 'include/linux/dm-log-userspace.h')
-rw-r--r--include/linux/dm-log-userspace.h18
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 {
/*