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-rw-r--r--include/linux/device-mapper.h4
-rw-r--r--include/linux/dm-log-userspace.h13
2 files changed, 16 insertions, 1 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 655e7721580a..df7607e6dce8 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -91,6 +91,9 @@ typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
iterate_devices_callout_fn fn,
void *data);
+typedef void (*dm_io_hints_fn) (struct dm_target *ti,
+ struct queue_limits *limits);
+
/*
* Returns:
* 0: The target can handle the next I/O immediately.
@@ -151,6 +154,7 @@ struct target_type {
dm_merge_fn merge;
dm_busy_fn busy;
dm_iterate_devices_fn iterate_devices;
+ dm_io_hints_fn io_hints;
/* For internal device-mapper use. */
struct list_head list;
diff --git a/include/linux/dm-log-userspace.h b/include/linux/dm-log-userspace.h
index 642e3017b51f..8a1f972c0fe9 100644
--- a/include/linux/dm-log-userspace.h
+++ b/include/linux/dm-log-userspace.h
@@ -371,7 +371,18 @@
(DM_ULOG_REQUEST_MASK & (request_type))
struct dm_ulog_request {
- char uuid[DM_UUID_LEN]; /* Ties a request to a specific mirror log */
+ /*
+ * The local unique identifier (luid) and the universally unique
+ * identifier (uuid) are used to tie a request to a specific
+ * mirror log. A single machine log could probably make due with
+ * just the 'luid', but a cluster-aware log must use the 'uuid' and
+ * the 'luid'. The uuid is what is required for node to node
+ * communication concerning a particular log, but the 'luid' helps
+ * differentiate between logs that are being swapped and have the
+ * same 'uuid'. (Think "live" and "inactive" device-mapper tables.)
+ */
+ uint64_t luid;
+ char uuid[DM_UUID_LEN];
char padding[7]; /* Padding because DM_UUID_LEN = 129 */
int32_t error; /* Used to report back processing errors */