ocfs2/cluster: Heartbeat mismatch message improved

If o2hb finds unexpected values in the heartbeat slot, it prints a message
"ERROR: Device "dm-6": another node is heartbeating in our slot!"

This message could be misleading. This patch adds two more messages to
help users better diagnose the problem.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <jlbec@evilplan.org>

1 files changed, 31 insertions, 17 deletions

diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 1d28505caff8..9a3e6bbff27b 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -539,25 +539,41 @@ static int o2hb_verify_crc(struct o2hb_region *reg,
 
 /* We want to make sure that nobody is heartbeating on top of us --
  * this will help detect an invalid configuration. */
-static int o2hb_check_last_timestamp(struct o2hb_region *reg)
+static void o2hb_check_last_timestamp(struct o2hb_region *reg)
 {
-        int node_num, ret;
         struct o2hb_disk_slot *slot;
         struct o2hb_disk_heartbeat_block *hb_block;
+        char *errstr;
 
-        node_num = o2nm_this_node();
-
-        ret = 1;
-        slot = &reg->hr_slots[node_num];
+        slot = &reg->hr_slots[o2nm_this_node()];
         /* Don't check on our 1st timestamp */
-        if (slot->ds_last_time) {
-                hb_block = slot->ds_raw_block;
+        if (!slot->ds_last_time)
+                return;
 
-                if (le64_to_cpu(hb_block->hb_seq) != slot->ds_last_time)
-                        ret = 0;
-        }
+        hb_block = slot->ds_raw_block;
+        if (le64_to_cpu(hb_block->hb_seq) == slot->ds_last_time &&
+            le64_to_cpu(hb_block->hb_generation) == slot->ds_last_generation &&
+            hb_block->hb_node == slot->ds_node_num)
+                return;
 
-        return ret;
+#define ERRSTR1         "Another node is heartbeating on device"
+#define ERRSTR2         "Heartbeat generation mismatch on device"
+#define ERRSTR3         "Heartbeat sequence mismatch on device"
+
+        if (hb_block->hb_node != slot->ds_node_num)
+                errstr = ERRSTR1;
+        else if (le64_to_cpu(hb_block->hb_generation) !=
+                 slot->ds_last_generation)
+                errstr = ERRSTR2;
+        else
+                errstr = ERRSTR3;
+
+        mlog(ML_ERROR, "%s (%s): expected(%u:0x%llx, 0x%llx), "
+             "ondisk(%u:0x%llx, 0x%llx)\n", errstr, reg->hr_dev_name,
+             slot->ds_node_num, (unsigned long long)slot->ds_last_generation,
+             (unsigned long long)slot->ds_last_time, hb_block->hb_node,
+             (unsigned long long)le64_to_cpu(hb_block->hb_generation),
+             (unsigned long long)le64_to_cpu(hb_block->hb_seq));
 }
 
 static inline void o2hb_prepare_block(struct o2hb_region *reg,
@@ -983,9 +999,7 @@ static int o2hb_do_disk_heartbeat(struct o2hb_region *reg)
         /* With an up to date view of the slots, we can check that no
          * other node has been improperly configured to heartbeat in
          * our slot. */
-        if (!o2hb_check_last_timestamp(reg))
-                mlog(ML_ERROR, "Device \"%s\": another node is heartbeating "
-                     "in our slot!\n", reg->hr_dev_name);
+        o2hb_check_last_timestamp(reg);
 
         /* fill in the proper info for our next heartbeat */
         o2hb_prepare_block(reg, reg->hr_generation);
@@ -999,8 +1013,8 @@ static int o2hb_do_disk_heartbeat(struct o2hb_region *reg)
         }
 
         i = -1;
-        while((i = find_next_bit(configured_nodes, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
-
+        while((i = find_next_bit(configured_nodes,
+                                 O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
                 change |= o2hb_check_slot(reg, &reg->hr_slots[i]);
         }