4 files changed, 31 insertions, 13 deletions

diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c
index c49da0a41c8e..6e186b1a062d 100644
--- a/drivers/md/dm-log-userspace-base.c
+++ b/drivers/md/dm-log-userspace-base.c
@@ -21,6 +21,7 @@ struct log_c {
         struct dm_target *ti;
         uint32_t region_size;
         region_t region_count;
+        uint64_t luid;
         char uuid[DM_UUID_LEN];
 
         char *usr_argv_str;
@@ -63,7 +64,7 @@ static int userspace_do_request(struct log_c *lc, const char *uuid,
          * restored.
          */
 retry:
-        r = dm_consult_userspace(uuid, request_type, data,
+        r = dm_consult_userspace(uuid, lc->luid, request_type, data,
                                  data_size, rdata, rdata_size);
 
         if (r != -ESRCH)
@@ -74,14 +75,15 @@ retry:
                 set_current_state(TASK_INTERRUPTIBLE);
                 schedule_timeout(2*HZ);
                 DMWARN("Attempting to contact userspace log server...");
-                r = dm_consult_userspace(uuid, DM_ULOG_CTR, lc->usr_argv_str,
+                r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_CTR,
+                                         lc->usr_argv_str,
                                          strlen(lc->usr_argv_str) + 1,
                                          NULL, NULL);
                 if (!r)
                         break;
         }
         DMINFO("Reconnected to userspace log server... DM_ULOG_CTR complete");
-        r = dm_consult_userspace(uuid, DM_ULOG_RESUME, NULL,
+        r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_RESUME, NULL,
                                  0, NULL, NULL);
         if (!r)
                 goto retry;
@@ -153,6 +155,9 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
                 return -ENOMEM;
         }
 
+        /* The ptr value is sufficient for local unique id */
+        lc->luid = (uint64_t)lc;
+
         lc->ti = ti;
 
         if (strlen(argv[0]) > (DM_UUID_LEN - 1)) {
@@ -172,7 +177,7 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
         }
 
         /* Send table string */
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_CTR,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_CTR,
                                  ctr_str, str_size, NULL, NULL);
 
         if (r == -ESRCH) {
@@ -182,7 +187,7 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 
         /* Since the region size does not change, get it now */
         rdata_size = sizeof(rdata);
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_GET_REGION_SIZE,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_GET_REGION_SIZE,
                                  NULL, 0, (char *)&rdata, &rdata_size);
 
         if (r) {
@@ -211,7 +216,7 @@ static void userspace_dtr(struct dm_dirty_log *log)
         int r;
         struct log_c *lc = log->context;
 
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_DTR,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_DTR,
                                  NULL, 0,
                                  NULL, NULL);
 
@@ -226,7 +231,7 @@ static int userspace_presuspend(struct dm_dirty_log *log)
         int r;
         struct log_c *lc = log->context;
 
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_PRESUSPEND,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_PRESUSPEND,
                                  NULL, 0,
                                  NULL, NULL);
 
@@ -238,7 +243,7 @@ static int userspace_postsuspend(struct dm_dirty_log *log)
         int r;
         struct log_c *lc = log->context;
 
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_POSTSUSPEND,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_POSTSUSPEND,
                                  NULL, 0,
                                  NULL, NULL);
 
@@ -251,7 +256,7 @@ static int userspace_resume(struct dm_dirty_log *log)
         struct log_c *lc = log->context;
 
         lc->in_sync_hint = 0;
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_RESUME,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_RESUME,
                                  NULL, 0,
                                  NULL, NULL);
 
diff --git a/drivers/md/dm-log-userspace-transfer.c b/drivers/md/dm-log-userspace-transfer.c
index 8ce74d95ae4d..ba0edad2d048 100644
--- a/drivers/md/dm-log-userspace-transfer.c
+++ b/drivers/md/dm-log-userspace-transfer.c
@@ -147,7 +147,8 @@ static void cn_ulog_callback(void *data)
 
 /**
  * dm_consult_userspace
- * @uuid: log's uuid (must be DM_UUID_LEN in size)
+ * @uuid: log's universal unique identifier (must be DM_UUID_LEN in size)
+ * @luid: log's local unique identifier
  * @request_type:  found in include/linux/dm-log-userspace.h
  * @data: data to tx to the server
  * @data_size: size of data in bytes
@@ -163,7 +164,7 @@ static void cn_ulog_callback(void *data)
  *
  * Returns: 0 on success, -EXXX on failure
  **/
-int dm_consult_userspace(const char *uuid, int request_type,
+int dm_consult_userspace(const char *uuid, uint64_t luid, int request_type,
                          char *data, size_t data_size,
                          char *rdata, size_t *rdata_size)
 {
@@ -190,6 +191,7 @@ resend:
 
         memset(tfr, 0, DM_ULOG_PREALLOCED_SIZE - overhead_size);
         memcpy(tfr->uuid, uuid, DM_UUID_LEN);
+        tfr->luid = luid;
         tfr->seq = dm_ulog_seq++;
 
         /*
diff --git a/drivers/md/dm-log-userspace-transfer.h b/drivers/md/dm-log-userspace-transfer.h
index c26d8e4e2710..04ee874f9153 100644
--- a/drivers/md/dm-log-userspace-transfer.h
+++ b/drivers/md/dm-log-userspace-transfer.h
@@ -11,7 +11,7 @@
 
 int dm_ulog_tfr_init(void);
 void dm_ulog_tfr_exit(void);
-int dm_consult_userspace(const char *uuid, int request_type,
+int dm_consult_userspace(const char *uuid, uint64_t luid, int request_type,
                          char *data, size_t data_size,
                          char *rdata, size_t *rdata_size);
 
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 */