1 files changed, 103 insertions, 0 deletions

diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 78ac3a00eb54..940be4c13b1f 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -239,6 +239,8 @@ static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
 static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
                                        struct dlm_lock_resource *res,
                                        u8 target);
+static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
+                                       struct dlm_lock_resource *res);
 
 
 int dlm_is_host_down(int errno)
@@ -677,6 +679,7 @@ struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
         struct dlm_node_iter iter;
         unsigned int namelen;
         int tries = 0;
+        int bit, wait_on_recovery = 0;
 
         BUG_ON(!lockid);
 
@@ -762,6 +765,18 @@ lookup:
                 dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
                 set_bit(dlm->node_num, mle->maybe_map);
                 list_add(&mle->list, &dlm->master_list);
+
+                /* still holding the dlm spinlock, check the recovery map
+                 * to see if there are any nodes that still need to be 
+                 * considered.  these will not appear in the mle nodemap
+                 * but they might own this lockres.  wait on them. */
+                bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
+                if (bit < O2NM_MAX_NODES) {
+                        mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to"
+                             "recover before lock mastery can begin\n",
+                             dlm->name, namelen, (char *)lockid, bit);
+                        wait_on_recovery = 1;
+                }
         }
 
         /* at this point there is either a DLM_MLE_BLOCK or a
@@ -779,6 +794,39 @@ lookup:
         spin_unlock(&dlm->master_lock);
         spin_unlock(&dlm->spinlock);
 
+        while (wait_on_recovery) {
+                /* any cluster changes that occurred after dropping the
+                 * dlm spinlock would be detectable be a change on the mle,
+                 * so we only need to clear out the recovery map once. */
+                if (dlm_is_recovery_lock(lockid, namelen)) {
+                        mlog(ML_NOTICE, "%s: recovery map is not empty, but "
+                             "must master $RECOVERY lock now\n", dlm->name);
+                        if (!dlm_pre_master_reco_lockres(dlm, res))
+                                wait_on_recovery = 0;
+                        else {
+                                mlog(0, "%s: waiting 500ms for heartbeat state "
+                                    "change\n", dlm->name);
+                                msleep(500);
+                        }
+                        continue;
+                } 
+
+                dlm_kick_recovery_thread(dlm);
+                msleep(100);
+                dlm_wait_for_recovery(dlm);
+
+                spin_lock(&dlm->spinlock);
+                bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
+                if (bit < O2NM_MAX_NODES) {
+                        mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to"
+                             "recover before lock mastery can begin\n",
+                             dlm->name, namelen, (char *)lockid, bit);
+                        wait_on_recovery = 1;
+                } else
+                        wait_on_recovery = 0;
+                spin_unlock(&dlm->spinlock);
+        }
+
         /* must wait for lock to be mastered elsewhere */
         if (blocked)
                 goto wait;
@@ -1835,6 +1883,61 @@ static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
         mlog(0, "finished with dlm_assert_master_worker\n");
 }
 
+/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
+ * We cannot wait for node recovery to complete to begin mastering this
+ * lockres because this lockres is used to kick off recovery! ;-)
+ * So, do a pre-check on all living nodes to see if any of those nodes
+ * think that $RECOVERY is currently mastered by a dead node.  If so,
+ * we wait a short time to allow that node to get notified by its own
+ * heartbeat stack, then check again.  All $RECOVERY lock resources
+ * mastered by dead nodes are purged when the hearbeat callback is 
+ * fired, so we can know for sure that it is safe to continue once
+ * the node returns a live node or no node.  */
+static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
+                                       struct dlm_lock_resource *res)
+{
+        struct dlm_node_iter iter;
+        int nodenum;
+        int ret = 0;
+        u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
+
+        spin_lock(&dlm->spinlock);
+        dlm_node_iter_init(dlm->domain_map, &iter);
+        spin_unlock(&dlm->spinlock);
+
+        while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
+                /* do not send to self */
+                if (nodenum == dlm->node_num)
+                        continue;
+                ret = dlm_do_master_requery(dlm, res, nodenum, &master);
+                if (ret < 0) {
+                        mlog_errno(ret);
+                        if (!dlm_is_host_down(ret))
+                                BUG();
+                        /* host is down, so answer for that node would be
+                         * DLM_LOCK_RES_OWNER_UNKNOWN.  continue. */
+                }
+
+                if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
+                        /* check to see if this master is in the recovery map */
+                        spin_lock(&dlm->spinlock);
+                        if (test_bit(master, dlm->recovery_map)) {
+                                mlog(ML_NOTICE, "%s: node %u has not seen "
+                                     "node %u go down yet, and thinks the "
+                                     "dead node is mastering the recovery "
+                                     "lock.  must wait.\n", dlm->name,
+                                     nodenum, master);
+                                ret = -EAGAIN;
+                        }
+                        spin_unlock(&dlm->spinlock);
+                        mlog(0, "%s: reco lock master is %u\n", dlm->name, 
+                             master);
+                        break;
+                }
+        }
+        return ret;
+}
+
 
 /*
  * DLM_MIGRATE_LOCKRES