Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2955 insertions, 0 deletions

diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
new file mode 100644
index 000000000..52ad342fe
--- /dev/null
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -0,0 +1,2955 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * dlmrecovery.c
+ *
+ * recovery stuff
+ *
+ * Copyright (C) 2004 Oracle.  All rights reserved.
+ */
+
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/init.h>
+#include <linux/sysctl.h>
+#include <linux/random.h>
+#include <linux/blkdev.h>
+#include <linux/socket.h>
+#include <linux/inet.h>
+#include <linux/timer.h>
+#include <linux/kthread.h>
+#include <linux/delay.h>
+
+
+#include "../cluster/heartbeat.h"
+#include "../cluster/nodemanager.h"
+#include "../cluster/tcp.h"
+
+#include "dlmapi.h"
+#include "dlmcommon.h"
+#include "dlmdomain.h"
+
+#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_RECOVERY)
+#include "../cluster/masklog.h"
+
+static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node);
+
+static int dlm_recovery_thread(void *data);
+static int dlm_do_recovery(struct dlm_ctxt *dlm);
+
+static int dlm_pick_recovery_master(struct dlm_ctxt *dlm);
+static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node);
+static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
+static int dlm_request_all_locks(struct dlm_ctxt *dlm,
+				 u8 request_from, u8 dead_node);
+static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm);
+
+static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res);
+static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
+					const char *lockname, int namelen,
+					int total_locks, u64 cookie,
+					u8 flags, u8 master);
+static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
+				    struct dlm_migratable_lockres *mres,
+				    u8 send_to,
+				    struct dlm_lock_resource *res,
+				    int total_locks);
+static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
+				     struct dlm_lock_resource *res,
+				     struct dlm_migratable_lockres *mres);
+static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
+static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
+				 u8 dead_node, u8 send_to);
+static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
+static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
+					struct list_head *list, u8 dead_node);
+static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
+					      u8 dead_node, u8 new_master);
+static void dlm_reco_ast(void *astdata);
+static void dlm_reco_bast(void *astdata, int blocked_type);
+static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
+static void dlm_request_all_locks_worker(struct dlm_work_item *item,
+					 void *data);
+static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
+static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
+				      struct dlm_lock_resource *res,
+				      u8 *real_master);
+
+static u64 dlm_get_next_mig_cookie(void);
+
+static DEFINE_SPINLOCK(dlm_reco_state_lock);
+static DEFINE_SPINLOCK(dlm_mig_cookie_lock);
+static u64 dlm_mig_cookie = 1;
+
+static u64 dlm_get_next_mig_cookie(void)
+{
+	u64 c;
+	spin_lock(&dlm_mig_cookie_lock);
+	c = dlm_mig_cookie;
+	if (dlm_mig_cookie == (~0ULL))
+		dlm_mig_cookie = 1;
+	else
+		dlm_mig_cookie++;
+	spin_unlock(&dlm_mig_cookie_lock);
+	return c;
+}
+
+static inline void dlm_set_reco_dead_node(struct dlm_ctxt *dlm,
+					  u8 dead_node)
+{
+	assert_spin_locked(&dlm->spinlock);
+	if (dlm->reco.dead_node != dead_node)
+		mlog(0, "%s: changing dead_node from %u to %u\n",
+		     dlm->name, dlm->reco.dead_node, dead_node);
+	dlm->reco.dead_node = dead_node;
+}
+
+static inline void dlm_set_reco_master(struct dlm_ctxt *dlm,
+				       u8 master)
+{
+	assert_spin_locked(&dlm->spinlock);
+	mlog(0, "%s: changing new_master from %u to %u\n",
+	     dlm->name, dlm->reco.new_master, master);
+	dlm->reco.new_master = master;
+}
+
+static inline void __dlm_reset_recovery(struct dlm_ctxt *dlm)
+{
+	assert_spin_locked(&dlm->spinlock);
+	clear_bit(dlm->reco.dead_node, dlm->recovery_map);
+	dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
+	dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
+}
+
+/* Worker function used during recovery. */
+void dlm_dispatch_work(struct work_struct *work)
+{
+	struct dlm_ctxt *dlm =
+		container_of(work, struct dlm_ctxt, dispatched_work);
+	LIST_HEAD(tmp_list);
+	struct dlm_work_item *item, *next;
+	dlm_workfunc_t *workfunc;
+	int tot=0;
+
+	spin_lock(&dlm->work_lock);
+	list_splice_init(&dlm->work_list, &tmp_list);
+	spin_unlock(&dlm->work_lock);
+
+	list_for_each_entry(item, &tmp_list, list) {
+		tot++;
+	}
+	mlog(0, "%s: work thread has %d work items\n", dlm->name, tot);
+
+	list_for_each_entry_safe(item, next, &tmp_list, list) {
+		workfunc = item->func;
+		list_del_init(&item->list);
+
+		/* already have ref on dlm to avoid having
+		 * it disappear.  just double-check. */
+		BUG_ON(item->dlm != dlm);
+
+		/* this is allowed to sleep and
+		 * call network stuff */
+		workfunc(item, item->data);
+
+		dlm_put(dlm);
+		kfree(item);
+	}
+}
+
+/*
+ * RECOVERY THREAD
+ */
+
+void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
+{
+	/* wake the recovery thread
+	 * this will wake the reco thread in one of three places
+	 * 1) sleeping with no recovery happening
+	 * 2) sleeping with recovery mastered elsewhere
+	 * 3) recovery mastered here, waiting on reco data */
+
+	wake_up(&dlm->dlm_reco_thread_wq);
+}
+
+/* Launch the recovery thread */
+int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
+{
+	mlog(0, "starting dlm recovery thread...\n");
+
+	dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
+			"dlm_reco-%s", dlm->name);
+	if (IS_ERR(dlm->dlm_reco_thread_task)) {
+		mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
+		dlm->dlm_reco_thread_task = NULL;
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
+{
+	if (dlm->dlm_reco_thread_task) {
+		mlog(0, "waiting for dlm recovery thread to exit\n");
+		kthread_stop(dlm->dlm_reco_thread_task);
+		dlm->dlm_reco_thread_task = NULL;
+	}
+}
+
+
+
+/*
+ * this is lame, but here's how recovery works...
+ * 1) all recovery threads cluster wide will work on recovering
+ *    ONE node at a time
+ * 2) negotiate who will take over all the locks for the dead node.
+ *    thats right... ALL the locks.
+ * 3) once a new master is chosen, everyone scans all locks
+ *    and moves aside those mastered by the dead guy
+ * 4) each of these locks should be locked until recovery is done
+ * 5) the new master collects up all of secondary lock queue info
+ *    one lock at a time, forcing each node to communicate back
+ *    before continuing
+ * 6) each secondary lock queue responds with the full known lock info
+ * 7) once the new master has run all its locks, it sends a ALLDONE!
+ *    message to everyone
+ * 8) upon receiving this message, the secondary queue node unlocks
+ *    and responds to the ALLDONE
+ * 9) once the new master gets responses from everyone, he unlocks
+ *    everything and recovery for this dead node is done
+ *10) go back to 2) while there are still dead nodes
+ *
+ */
+
+static void dlm_print_reco_node_status(struct dlm_ctxt *dlm)
+{
+	struct dlm_reco_node_data *ndata;
+	struct dlm_lock_resource *res;
+
+	mlog(ML_NOTICE, "%s(%d): recovery info, state=%s, dead=%u, master=%u\n",
+	     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
+	     dlm->reco.state & DLM_RECO_STATE_ACTIVE ? "ACTIVE" : "inactive",
+	     dlm->reco.dead_node, dlm->reco.new_master);
+
+	list_for_each_entry(ndata, &dlm->reco.node_data, list) {
+		char *st = "unknown";
+		switch (ndata->state) {
+			case DLM_RECO_NODE_DATA_INIT:
+				st = "init";
+				break;
+			case DLM_RECO_NODE_DATA_REQUESTING:
+				st = "requesting";
+				break;
+			case DLM_RECO_NODE_DATA_DEAD:
+				st = "dead";
+				break;
+			case DLM_RECO_NODE_DATA_RECEIVING:
+				st = "receiving";
+				break;
+			case DLM_RECO_NODE_DATA_REQUESTED:
+				st = "requested";
+				break;
+			case DLM_RECO_NODE_DATA_DONE:
+				st = "done";
+				break;
+			case DLM_RECO_NODE_DATA_FINALIZE_SENT:
+				st = "finalize-sent";
+				break;
+			default:
+				st = "bad";
+				break;
+		}
+		mlog(ML_NOTICE, "%s: reco state, node %u, state=%s\n",
+		     dlm->name, ndata->node_num, st);
+	}
+	list_for_each_entry(res, &dlm->reco.resources, recovering) {
+		mlog(ML_NOTICE, "%s: lockres %.*s on recovering list\n",
+		     dlm->name, res->lockname.len, res->lockname.name);
+	}
+}
+
+#define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)
+
+static int dlm_recovery_thread(void *data)
+{
+	int status;
+	struct dlm_ctxt *dlm = data;
+	unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);
+
+	mlog(0, "dlm thread running for %s...\n", dlm->name);
+
+	while (!kthread_should_stop()) {
+		if (dlm_domain_fully_joined(dlm)) {
+			status = dlm_do_recovery(dlm);
+			if (status == -EAGAIN) {
+				/* do not sleep, recheck immediately. */
+				continue;
+			}
+			if (status < 0)
+				mlog_errno(status);
+		}
+
+		wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
+						 kthread_should_stop(),
+						 timeout);
+	}
+
+	mlog(0, "quitting DLM recovery thread\n");
+	return 0;
+}
+
+/* returns true when the recovery master has contacted us */
+static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
+{
+	int ready;
+	spin_lock(&dlm->spinlock);
+	ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
+	spin_unlock(&dlm->spinlock);
+	return ready;
+}
+
+/* returns true if node is no longer in the domain
+ * could be dead or just not joined */
+int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
+{
+	int dead;
+	spin_lock(&dlm->spinlock);
+	dead = !test_bit(node, dlm->domain_map);
+	spin_unlock(&dlm->spinlock);
+	return dead;
+}
+
+/* returns true if node is no longer in the domain
+ * could be dead or just not joined */
+static int dlm_is_node_recovered(struct dlm_ctxt *dlm, u8 node)
+{
+	int recovered;
+	spin_lock(&dlm->spinlock);
+	recovered = !test_bit(node, dlm->recovery_map);
+	spin_unlock(&dlm->spinlock);
+	return recovered;
+}
+
+
+void dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
+{
+	if (dlm_is_node_dead(dlm, node))
+		return;
+
+	printk(KERN_NOTICE "o2dlm: Waiting on the death of node %u in "
+	       "domain %s\n", node, dlm->name);
+
+	if (timeout)
+		wait_event_timeout(dlm->dlm_reco_thread_wq,
+				   dlm_is_node_dead(dlm, node),
+				   msecs_to_jiffies(timeout));
+	else
+		wait_event(dlm->dlm_reco_thread_wq,
+			   dlm_is_node_dead(dlm, node));
+}
+
+void dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout)
+{
+	if (dlm_is_node_recovered(dlm, node))
+		return;
+
+	printk(KERN_NOTICE "o2dlm: Waiting on the recovery of node %u in "
+	       "domain %s\n", node, dlm->name);
+
+	if (timeout)
+		wait_event_timeout(dlm->dlm_reco_thread_wq,
+				   dlm_is_node_recovered(dlm, node),
+				   msecs_to_jiffies(timeout));
+	else
+		wait_event(dlm->dlm_reco_thread_wq,
+			   dlm_is_node_recovered(dlm, node));
+}
+
+/* callers of the top-level api calls (dlmlock/dlmunlock) should
+ * block on the dlm->reco.event when recovery is in progress.
+ * the dlm recovery thread will set this state when it begins
+ * recovering a dead node (as the new master or not) and clear
+ * the state and wake as soon as all affected lock resources have
+ * been marked with the RECOVERY flag */
+static int dlm_in_recovery(struct dlm_ctxt *dlm)
+{
+	int in_recovery;
+	spin_lock(&dlm->spinlock);
+	in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
+	spin_unlock(&dlm->spinlock);
+	return in_recovery;
+}
+
+
+void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
+{
+	if (dlm_in_recovery(dlm)) {
+		mlog(0, "%s: reco thread %d in recovery: "
+		     "state=%d, master=%u, dead=%u\n",
+		     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
+		     dlm->reco.state, dlm->reco.new_master,
+		     dlm->reco.dead_node);
+	}
+	wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
+}
+
+static void dlm_begin_recovery(struct dlm_ctxt *dlm)
+{
+	assert_spin_locked(&dlm->spinlock);
+	BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
+	printk(KERN_NOTICE "o2dlm: Begin recovery on domain %s for node %u\n",
+	       dlm->name, dlm->reco.dead_node);
+	dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
+}
+
+static void dlm_end_recovery(struct dlm_ctxt *dlm)
+{
+	spin_lock(&dlm->spinlock);
+	BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
+	dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
+	spin_unlock(&dlm->spinlock);
+	printk(KERN_NOTICE "o2dlm: End recovery on domain %s\n", dlm->name);
+	wake_up(&dlm->reco.event);
+}
+
+static void dlm_print_recovery_master(struct dlm_ctxt *dlm)
+{
+	printk(KERN_NOTICE "o2dlm: Node %u (%s) is the Recovery Master for the "
+	       "dead node %u in domain %s\n", dlm->reco.new_master,
+	       (dlm->node_num == dlm->reco.new_master ? "me" : "he"),
+	       dlm->reco.dead_node, dlm->name);
+}
+
+static int dlm_do_recovery(struct dlm_ctxt *dlm)
+{
+	int status = 0;
+	int ret;
+
+	spin_lock(&dlm->spinlock);
+
+	if (dlm->migrate_done) {
+		mlog(0, "%s: no need do recovery after migrating all "
+		     "lock resources\n", dlm->name);
+		spin_unlock(&dlm->spinlock);
+		return 0;
+	}
+
+	/* check to see if the new master has died */
+	if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
+	    test_bit(dlm->reco.new_master, dlm->recovery_map)) {
+		mlog(0, "new master %u died while recovering %u!\n",
+		     dlm->reco.new_master, dlm->reco.dead_node);
+		/* unset the new_master, leave dead_node */
+		dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
+	}
+
+	/* select a target to recover */
+	if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
+		int bit;
+
+		bit = find_first_bit(dlm->recovery_map, O2NM_MAX_NODES);
+		if (bit >= O2NM_MAX_NODES || bit < 0)
+			dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
+		else
+			dlm_set_reco_dead_node(dlm, bit);
+	} else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
+		/* BUG? */
+		mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
+		     dlm->reco.dead_node);
+		dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
+	}
+
+	if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
+		// mlog(0, "nothing to recover!  sleeping now!\n");
+		spin_unlock(&dlm->spinlock);
+		/* return to main thread loop and sleep. */
+		return 0;
+	}
+	mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n",
+	     dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
+	     dlm->reco.dead_node);
+
+	/* take write barrier */
+	/* (stops the list reshuffling thread, proxy ast handling) */
+	dlm_begin_recovery(dlm);
+
+	spin_unlock(&dlm->spinlock);
+
+	if (dlm->reco.new_master == dlm->node_num)
+		goto master_here;
+
+	if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
+		/* choose a new master, returns 0 if this node
+		 * is the master, -EEXIST if it's another node.
+		 * this does not return until a new master is chosen
+		 * or recovery completes entirely. */
+		ret = dlm_pick_recovery_master(dlm);
+		if (!ret) {
+			/* already notified everyone.  go. */
+			goto master_here;
+		}
+		mlog(0, "another node will master this recovery session.\n");
+	}
+
+	dlm_print_recovery_master(dlm);
+
+	/* it is safe to start everything back up here
+	 * because all of the dead node's lock resources
+	 * have been marked as in-recovery */
+	dlm_end_recovery(dlm);
+
+	/* sleep out in main dlm_recovery_thread loop. */
+	return 0;
+
+master_here:
+	dlm_print_recovery_master(dlm);
+
+	status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
+	if (status < 0) {
+		/* we should never hit this anymore */
+		mlog(ML_ERROR, "%s: Error %d remastering locks for node %u, "
+		     "retrying.\n", dlm->name, status, dlm->reco.dead_node);
+		/* yield a bit to allow any final network messages
+		 * to get handled on remaining nodes */
+		msleep(100);
+	} else {
+		/* success!  see if any other nodes need recovery */
+		mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
+		     dlm->name, dlm->reco.dead_node, dlm->node_num);
+		spin_lock(&dlm->spinlock);
+		__dlm_reset_recovery(dlm);
+		dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
+		spin_unlock(&dlm->spinlock);
+	}
+	dlm_end_recovery(dlm);
+
+	/* continue and look for another dead node */
+	return -EAGAIN;
+}
+
+static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
+{
+	int status = 0;
+	struct dlm_reco_node_data *ndata;
+	int all_nodes_done;
+	int destroy = 0;
+	int pass = 0;
+
+	do {
+		/* we have become recovery master.  there is no escaping
+		 * this, so just keep trying until we get it. */
+		status = dlm_init_recovery_area(dlm, dead_node);
+		if (status < 0) {
+			mlog(ML_ERROR, "%s: failed to alloc recovery area, "
+			     "retrying\n", dlm->name);
+			msleep(1000);
+		}
+	} while (status != 0);
+
+	/* safe to access the node data list without a lock, since this
+	 * process is the only one to change the list */
+	list_for_each_entry(ndata, &dlm->reco.node_data, list) {
+		BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
+		ndata->state = DLM_RECO_NODE_DATA_REQUESTING;
+
+		mlog(0, "%s: Requesting lock info from node %u\n", dlm->name,
+		     ndata->node_num);
+
+		if (ndata->node_num == dlm->node_num) {
+			ndata->state = DLM_RECO_NODE_DATA_DONE;
+			continue;
+		}
+
+		do {
+			status = dlm_request_all_locks(dlm, ndata->node_num,
+						       dead_node);
+			if (status < 0) {
+				mlog_errno(status);
+				if (dlm_is_host_down(status)) {
+					/* node died, ignore it for recovery */
+					status = 0;
+					ndata->state = DLM_RECO_NODE_DATA_DEAD;
+					/* wait for the domain map to catch up
+					 * with the network state. */
+					wait_event_timeout(dlm->dlm_reco_thread_wq,
+							   dlm_is_node_dead(dlm,
+								ndata->node_num),
+							   msecs_to_jiffies(1000));
+					mlog(0, "waited 1 sec for %u, "
+					     "dead? %s\n", ndata->node_num,
+					     dlm_is_node_dead(dlm, ndata->node_num) ?
+					     "yes" : "no");
+				} else {
+					/* -ENOMEM on the other node */
+					mlog(0, "%s: node %u returned "
+					     "%d during recovery, retrying "
+					     "after a short wait\n",
+					     dlm->name, ndata->node_num,
+					     status);
+					msleep(100);
+				}
+			}
+		} while (status != 0);
+
+		spin_lock(&dlm_reco_state_lock);
+		switch (ndata->state) {
+			case DLM_RECO_NODE_DATA_INIT:
+			case DLM_RECO_NODE_DATA_FINALIZE_SENT:
+			case DLM_RECO_NODE_DATA_REQUESTED:
+				BUG();
+				break;
+			case DLM_RECO_NODE_DATA_DEAD:
+				mlog(0, "node %u died after requesting "
+				     "recovery info for node %u\n",
+				     ndata->node_num, dead_node);
+				/* fine.  don't need this node's info.
+				 * continue without it. */
+				break;
+			case DLM_RECO_NODE_DATA_REQUESTING:
+				ndata->state = DLM_RECO_NODE_DATA_REQUESTED;
+				mlog(0, "now receiving recovery data from "
+				     "node %u for dead node %u\n",
+				     ndata->node_num, dead_node);
+				break;
+			case DLM_RECO_NODE_DATA_RECEIVING:
+				mlog(0, "already receiving recovery data from "
+				     "node %u for dead node %u\n",
+				     ndata->node_num, dead_node);
+				break;
+			case DLM_RECO_NODE_DATA_DONE:
+				mlog(0, "already DONE receiving recovery data "
+				     "from node %u for dead node %u\n",
+				     ndata->node_num, dead_node);
+				break;
+		}
+		spin_unlock(&dlm_reco_state_lock);
+	}
+
+	mlog(0, "%s: Done requesting all lock info\n", dlm->name);
+
+	/* nodes should be sending reco data now
+	 * just need to wait */
+
+	while (1) {
+		/* check all the nodes now to see if we are
+		 * done, or if anyone died */
+		all_nodes_done = 1;
+		spin_lock(&dlm_reco_state_lock);
+		list_for_each_entry(ndata, &dlm->reco.node_data, list) {
+			mlog(0, "checking recovery state of node %u\n",
+			     ndata->node_num);
+			switch (ndata->state) {
+				case DLM_RECO_NODE_DATA_INIT:
+				case DLM_RECO_NODE_DATA_REQUESTING:
+					mlog(ML_ERROR, "bad ndata state for "
+					     "node %u: state=%d\n",
+					     ndata->node_num, ndata->state);
+					BUG();
+					break;
+				case DLM_RECO_NODE_DATA_DEAD:
+					mlog(0, "node %u died after "
+					     "requesting recovery info for "
+					     "node %u\n", ndata->node_num,
+					     dead_node);
+					break;
+				case DLM_RECO_NODE_DATA_RECEIVING:
+				case DLM_RECO_NODE_DATA_REQUESTED:
+					mlog(0, "%s: node %u still in state %s\n",
+					     dlm->name, ndata->node_num,
+					     ndata->state==DLM_RECO_NODE_DATA_RECEIVING ?
+					     "receiving" : "requested");
+					all_nodes_done = 0;
+					break;
+				case DLM_RECO_NODE_DATA_DONE:
+					mlog(0, "%s: node %u state is done\n",
+					     dlm->name, ndata->node_num);
+					break;
+				case DLM_RECO_NODE_DATA_FINALIZE_SENT:
+					mlog(0, "%s: node %u state is finalize\n",
+					     dlm->name, ndata->node_num);
+					break;
+			}
+		}
+		spin_unlock(&dlm_reco_state_lock);
+
+		mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
+		     all_nodes_done?"yes":"no");
+		if (all_nodes_done) {
+			int ret;
+
+			/* Set this flag on recovery master to avoid
+			 * a new recovery for another dead node start
+			 * before the recovery is not done. That may
+			 * cause recovery hung.*/
+			spin_lock(&dlm->spinlock);
+			dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
+			spin_unlock(&dlm->spinlock);
+
+			/* all nodes are now in DLM_RECO_NODE_DATA_DONE state
+	 		 * just send a finalize message to everyone and
+	 		 * clean up */
+			mlog(0, "all nodes are done! send finalize\n");
+			ret = dlm_send_finalize_reco_message(dlm);
+			if (ret < 0)
+				mlog_errno(ret);
+
+			spin_lock(&dlm->spinlock);
+			dlm_finish_local_lockres_recovery(dlm, dead_node,
+							  dlm->node_num);
+			spin_unlock(&dlm->spinlock);
+			mlog(0, "should be done with recovery!\n");
+
+			mlog(0, "finishing recovery of %s at %lu, "
+			     "dead=%u, this=%u, new=%u\n", dlm->name,
+			     jiffies, dlm->reco.dead_node,
+			     dlm->node_num, dlm->reco.new_master);
+			destroy = 1;
+			status = 0;
+			/* rescan everything marked dirty along the way */
+			dlm_kick_thread(dlm, NULL);
+			break;
+		}
+		/* wait to be signalled, with periodic timeout
+		 * to check for node death */
+		wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
+					 kthread_should_stop(),
+					 msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));
+
+	}
+
+	if (destroy)
+		dlm_destroy_recovery_area(dlm);
+
+	return status;
+}
+
+static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
+{
+	int num=0;
+	struct dlm_reco_node_data *ndata;
+
+	spin_lock(&dlm->spinlock);
+	memcpy(dlm->reco.node_map, dlm->domain_map, sizeof(dlm->domain_map));
+	/* nodes can only be removed (by dying) after dropping
+	 * this lock, and death will be trapped later, so this should do */
+	spin_unlock(&dlm->spinlock);
+
+	while (1) {
+		num = find_next_bit (dlm->reco.node_map, O2NM_MAX_NODES, num);
+		if (num >= O2NM_MAX_NODES) {
+			break;
+		}
+		BUG_ON(num == dead_node);
+
+		ndata = kzalloc(sizeof(*ndata), GFP_NOFS);
+		if (!ndata) {
+			dlm_destroy_recovery_area(dlm);
+			return -ENOMEM;
+		}
+		ndata->node_num = num;
+		ndata->state = DLM_RECO_NODE_DATA_INIT;
+		spin_lock(&dlm_reco_state_lock);
+		list_add_tail(&ndata->list, &dlm->reco.node_data);
+		spin_unlock(&dlm_reco_state_lock);
+		num++;
+	}
+
+	return 0;
+}
+
+static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm)
+{
+	struct dlm_reco_node_data *ndata, *next;
+	LIST_HEAD(tmplist);
+
+	spin_lock(&dlm_reco_state_lock);
+	list_splice_init(&dlm->reco.node_data, &tmplist);
+	spin_unlock(&dlm_reco_state_lock);
+
+	list_for_each_entry_safe(ndata, next, &tmplist, list) {
+		list_del_init(&ndata->list);
+		kfree(ndata);
+	}
+}
+
+static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
+				 u8 dead_node)
+{
+	struct dlm_lock_request lr;
+	int ret;
+	int status;
+
+	mlog(0, "\n");
+
+
+	mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
+		  "to %u\n", dead_node, request_from);
+
+	memset(&lr, 0, sizeof(lr));
+	lr.node_idx = dlm->node_num;
+	lr.dead_node = dead_node;
+
+	// send message
+	ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
+				 &lr, sizeof(lr), request_from, &status);
+
+	/* negative status is handled by caller */
+	if (ret < 0)
+		mlog(ML_ERROR, "%s: Error %d send LOCK_REQUEST to node %u "
+		     "to recover dead node %u\n", dlm->name, ret,
+		     request_from, dead_node);
+	else
+		ret = status;
+	// return from here, then
+	// sleep until all received or error
+	return ret;
+
+}
+
+int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data,
+				  void **ret_data)
+{
+	struct dlm_ctxt *dlm = data;
+	struct dlm_lock_request *lr = (struct dlm_lock_request *)msg->buf;
+	char *buf = NULL;
+	struct dlm_work_item *item = NULL;
+
+	if (!dlm_grab(dlm))
+		return -EINVAL;
+
+	if (lr->dead_node != dlm->reco.dead_node) {
+		mlog(ML_ERROR, "%s: node %u sent dead_node=%u, but local "
+		     "dead_node is %u\n", dlm->name, lr->node_idx,
+		     lr->dead_node, dlm->reco.dead_node);
+		dlm_print_reco_node_status(dlm);
+		/* this is a hack */
+		dlm_put(dlm);
+		return -ENOMEM;
+	}
+	BUG_ON(lr->dead_node != dlm->reco.dead_node);
+
+	item = kzalloc(sizeof(*item), GFP_NOFS);
+	if (!item) {
+		dlm_put(dlm);
+		return -ENOMEM;
+	}
+
+	/* this will get freed by dlm_request_all_locks_worker */
+	buf = (char *) __get_free_page(GFP_NOFS);
+	if (!buf) {
+		kfree(item);
+		dlm_put(dlm);
+		return -ENOMEM;
+	}
+
+	/* queue up work for dlm_request_all_locks_worker */
+	dlm_grab(dlm);  /* get an extra ref for the work item */
+	dlm_init_work_item(dlm, item, dlm_request_all_locks_worker, buf);
+	item->u.ral.reco_master = lr->node_idx;
+	item->u.ral.dead_node = lr->dead_node;
+	spin_lock(&dlm->work_lock);
+	list_add_tail(&item->list, &dlm->work_list);
+	spin_unlock(&dlm->work_lock);
+	queue_work(dlm->dlm_worker, &dlm->dispatched_work);
+
+	dlm_put(dlm);
+	return 0;
+}
+
+static void dlm_request_all_locks_worker(struct dlm_work_item *item, void *data)
+{
+	struct dlm_migratable_lockres *mres;
+	struct dlm_lock_resource *res;
+	struct dlm_ctxt *dlm;
+	LIST_HEAD(resources);
+	int ret;
+	u8 dead_node, reco_master;
+	int skip_all_done = 0;
+
+	dlm = item->dlm;
+	dead_node = item->u.ral.dead_node;
+	reco_master = item->u.ral.reco_master;
+	mres = (struct dlm_migratable_lockres *)data;
+
+	mlog(0, "%s: recovery worker started, dead=%u, master=%u\n",
+	     dlm->name, dead_node, reco_master);
+
+	if (dead_node != dlm->reco.dead_node ||
+	    reco_master != dlm->reco.new_master) {
+		/* worker could have been created before the recovery master
+		 * died.  if so, do not continue, but do not error. */
+		if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
+			mlog(ML_NOTICE, "%s: will not send recovery state, "
+			     "recovery master %u died, thread=(dead=%u,mas=%u)"
+			     " current=(dead=%u,mas=%u)\n", dlm->name,
+			     reco_master, dead_node, reco_master,
+			     dlm->reco.dead_node, dlm->reco.new_master);
+		} else {
+			mlog(ML_NOTICE, "%s: reco state invalid: reco(dead=%u, "
+			     "master=%u), request(dead=%u, master=%u)\n",
+			     dlm->name, dlm->reco.dead_node,
+			     dlm->reco.new_master, dead_node, reco_master);
+		}
+		goto leave;
+	}
+
+	/* lock resources should have already been moved to the
+ 	 * dlm->reco.resources list.  now move items from that list
+ 	 * to a temp list if the dead owner matches.  note that the
+	 * whole cluster recovers only one node at a time, so we
+	 * can safely move UNKNOWN lock resources for each recovery
+	 * session. */
+	dlm_move_reco_locks_to_list(dlm, &resources, dead_node);
+
+	/* now we can begin blasting lockreses without the dlm lock */
+
+	/* any errors returned will be due to the new_master dying,
+	 * the dlm_reco_thread should detect this */
+	list_for_each_entry(res, &resources, recovering) {
+		ret = dlm_send_one_lockres(dlm, res, mres, reco_master,
+				   	DLM_MRES_RECOVERY);
+		if (ret < 0) {
+			mlog(ML_ERROR, "%s: node %u went down while sending "
+			     "recovery state for dead node %u, ret=%d\n", dlm->name,
+			     reco_master, dead_node, ret);
+			skip_all_done = 1;
+			break;
+		}
+	}
+
+	/* move the resources back to the list */
+	spin_lock(&dlm->spinlock);
+	list_splice_init(&resources, &dlm->reco.resources);
+	spin_unlock(&dlm->spinlock);
+
+	if (!skip_all_done) {
+		ret = dlm_send_all_done_msg(dlm, dead_node, reco_master);
+		if (ret < 0) {
+			mlog(ML_ERROR, "%s: node %u went down while sending "
+			     "recovery all-done for dead node %u, ret=%d\n",
+			     dlm->name, reco_master, dead_node, ret);
+		}
+	}
+leave:
+	free_page((unsigned long)data);
+}
+
+
+static int dlm_send_all_done_msg(struct dlm_ctxt *dlm, u8 dead_node, u8 send_to)
+{
+	int ret, tmpret;
+	struct dlm_reco_data_done done_msg;
+
+	memset(&done_msg, 0, sizeof(done_msg));
+	done_msg.node_idx = dlm->node_num;
+	done_msg.dead_node = dead_node;
+	mlog(0, "sending DATA DONE message to %u, "
+	     "my node=%u, dead node=%u\n", send_to, done_msg.node_idx,
+	     done_msg.dead_node);
+
+	ret = o2net_send_message(DLM_RECO_DATA_DONE_MSG, dlm->key, &done_msg,
+				 sizeof(done_msg), send_to, &tmpret);
+	if (ret < 0) {
+		mlog(ML_ERROR, "%s: Error %d send RECO_DATA_DONE to node %u "
+		     "to recover dead node %u\n", dlm->name, ret, send_to,
+		     dead_node);
+		if (!dlm_is_host_down(ret)) {
+			BUG();
+		}
+	} else
+		ret = tmpret;
+	return ret;
+}
+
+
+int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data,
+			       void **ret_data)
+{
+	struct dlm_ctxt *dlm = data;
+	struct dlm_reco_data_done *done = (struct dlm_reco_data_done *)msg->buf;
+	struct dlm_reco_node_data *ndata = NULL;
+	int ret = -EINVAL;
+
+	if (!dlm_grab(dlm))
+		return -EINVAL;
+
+	mlog(0, "got DATA DONE: dead_node=%u, reco.dead_node=%u, "
+	     "node_idx=%u, this node=%u\n", done->dead_node,
+	     dlm->reco.dead_node, done->node_idx, dlm->node_num);
+
+	mlog_bug_on_msg((done->dead_node != dlm->reco.dead_node),
+			"Got DATA DONE: dead_node=%u, reco.dead_node=%u, "
+			"node_idx=%u, this node=%u\n", done->dead_node,
+			dlm->reco.dead_node, done->node_idx, dlm->node_num);
+
+	spin_lock(&dlm_reco_state_lock);
+	list_for_each_entry(ndata, &dlm->reco.node_data, list) {
+		if (ndata->node_num != done->node_idx)
+			continue;
+
+		switch (ndata->state) {
+			/* should have moved beyond INIT but not to FINALIZE yet */
+			case DLM_RECO_NODE_DATA_INIT:
+			case DLM_RECO_NODE_DATA_DEAD:
+			case DLM_RECO_NODE_DATA_FINALIZE_SENT:
+				mlog(ML_ERROR, "bad ndata state for node %u:"
+				     " state=%d\n", ndata->node_num,
+				     ndata->state);
+				BUG();
+				break;
+			/* these states are possible at this point, anywhere along
+			 * the line of recovery */
+			case DLM_RECO_NODE_DATA_DONE:
+			case DLM_RECO_NODE_DATA_RECEIVING:
+			case DLM_RECO_NODE_DATA_REQUESTED:
+			case DLM_RECO_NODE_DATA_REQUESTING:
+				mlog(0, "node %u is DONE sending "
+					  "recovery data!\n",
+					  ndata->node_num);
+
+				ndata->state = DLM_RECO_NODE_DATA_DONE;
+				ret = 0;
+				break;
+		}
+	}
+	spin_unlock(&dlm_reco_state_lock);
+
+	/* wake the recovery thread, some node is done */
+	if (!ret)
+		dlm_kick_recovery_thread(dlm);
+
+	if (ret < 0)
+		mlog(ML_ERROR, "failed to find recovery node data for node "
+		     "%u\n", done->node_idx);
+	dlm_put(dlm);
+
+	mlog(0, "leaving reco data done handler, ret=%d\n", ret);
+	return ret;
+}
+
+static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
+					struct list_head *list,
+				       	u8 dead_node)
+{
+	struct dlm_lock_resource *res, *next;
+	struct dlm_lock *lock;
+
+	spin_lock(&dlm->spinlock);
+	list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
+		/* always prune any $RECOVERY entries for dead nodes,
+		 * otherwise hangs can occur during later recovery */
+		if (dlm_is_recovery_lock(res->lockname.name,
+					 res->lockname.len)) {
+			spin_lock(&res->spinlock);
+			list_for_each_entry(lock, &res->granted, list) {
+				if (lock->ml.node == dead_node) {
+					mlog(0, "AHA! there was "
+					     "a $RECOVERY lock for dead "
+					     "node %u (%s)!\n",
+					     dead_node, dlm->name);
+					list_del_init(&lock->list);
+					dlm_lock_put(lock);
+					/* Can't schedule DLM_UNLOCK_FREE_LOCK
+					 * - do manually */
+					dlm_lock_put(lock);
+					break;
+				}
+			}
+			spin_unlock(&res->spinlock);
+			continue;
+		}
+
+		if (res->owner == dead_node) {
+			mlog(0, "found lockres owned by dead node while "
+				  "doing recovery for node %u. sending it.\n",
+				  dead_node);
+			list_move_tail(&res->recovering, list);
+		} else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
+			mlog(0, "found UNKNOWN owner while doing recovery "
+				  "for node %u. sending it.\n", dead_node);
+			list_move_tail(&res->recovering, list);
+		}
+	}
+	spin_unlock(&dlm->spinlock);
+}
+
+static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res)
+{
+	int total_locks = 0;
+	struct list_head *iter, *queue = &res->granted;
+	int i;
+
+	for (i=0; i<3; i++) {
+		list_for_each(iter, queue)
+			total_locks++;
+		queue++;
+	}
+	return total_locks;
+}
+
+
+static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
+				      struct dlm_migratable_lockres *mres,
+				      u8 send_to,
+				      struct dlm_lock_resource *res,
+				      int total_locks)
+{
+	u64 mig_cookie = be64_to_cpu(mres->mig_cookie);
+	int mres_total_locks = be32_to_cpu(mres->total_locks);
+	int ret = 0, status = 0;
+	u8 orig_flags = mres->flags,
+	   orig_master = mres->master;
+
+	BUG_ON(mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS);
+	if (!mres->num_locks)
+		return 0;
+
+	/* add an all-done flag if we reached the last lock */
+	orig_flags = mres->flags;
+	BUG_ON(total_locks > mres_total_locks);
+	if (total_locks == mres_total_locks)
+		mres->flags |= DLM_MRES_ALL_DONE;
+
+	mlog(0, "%s:%.*s: sending mig lockres (%s) to %u\n",
+	     dlm->name, res->lockname.len, res->lockname.name,
+	     orig_flags & DLM_MRES_MIGRATION ? "migration" : "recovery",
+	     send_to);
+
+	/* send it */
+	ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
+				 struct_size(mres, ml, mres->num_locks),
+				 send_to, &status);
+	if (ret < 0) {
+		/* XXX: negative status is not handled.
+		 * this will end up killing this node. */
+		mlog(ML_ERROR, "%s: res %.*s, Error %d send MIG_LOCKRES to "
+		     "node %u (%s)\n", dlm->name, mres->lockname_len,
+		     mres->lockname, ret, send_to,
+		     (orig_flags & DLM_MRES_MIGRATION ?
+		      "migration" : "recovery"));
+	} else {
+		/* might get an -ENOMEM back here */
+		ret = status;
+		if (ret < 0) {
+			mlog_errno(ret);
+
+			if (ret == -EFAULT) {
+				mlog(ML_ERROR, "node %u told me to kill "
+				     "myself!\n", send_to);
+				BUG();
+			}
+		}
+	}
+
+	/* zero and reinit the message buffer */
+	dlm_init_migratable_lockres(mres, res->lockname.name,
+				    res->lockname.len, mres_total_locks,
+				    mig_cookie, orig_flags, orig_master);
+	return ret;
+}
+
+static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
+					const char *lockname, int namelen,
+					int total_locks, u64 cookie,
+					u8 flags, u8 master)
+{
+	/* mres here is one full page */
+	clear_page(mres);
+	mres->lockname_len = namelen;
+	memcpy(mres->lockname, lockname, namelen);
+	mres->num_locks = 0;
+	mres->total_locks = cpu_to_be32(total_locks);
+	mres->mig_cookie = cpu_to_be64(cookie);
+	mres->flags = flags;
+	mres->master = master;
+}
+
+static void dlm_prepare_lvb_for_migration(struct dlm_lock *lock,
+					  struct dlm_migratable_lockres *mres,
+					  int queue)
+{
+	if (!lock->lksb)
+	       return;
+
+	/* Ignore lvb in all locks in the blocked list */
+	if (queue == DLM_BLOCKED_LIST)
+		return;
+
+	/* Only consider lvbs in locks with granted EX or PR lock levels */
+	if (lock->ml.type != LKM_EXMODE && lock->ml.type != LKM_PRMODE)
+		return;
+
+	if (dlm_lvb_is_empty(mres->lvb)) {
+		memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
+		return;
+	}
+
+	/* Ensure the lvb copied for migration matches in other valid locks */
+	if (!memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))
+		return;
+
+	mlog(ML_ERROR, "Mismatched lvb in lock cookie=%u:%llu, name=%.*s, "
+	     "node=%u\n",
+	     dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
+	     dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
+	     lock->lockres->lockname.len, lock->lockres->lockname.name,
+	     lock->ml.node);
+	dlm_print_one_lock_resource(lock->lockres);
+	BUG();
+}
+
+/* returns 1 if this lock fills the network structure,
+ * 0 otherwise */
+static int dlm_add_lock_to_array(struct dlm_lock *lock,
+				 struct dlm_migratable_lockres *mres, int queue)
+{
+	struct dlm_migratable_lock *ml;
+	int lock_num = mres->num_locks;
+
+	ml = &(mres->ml[lock_num]);
+	ml->cookie = lock->ml.cookie;
+	ml->type = lock->ml.type;
+	ml->convert_type = lock->ml.convert_type;
+	ml->highest_blocked = lock->ml.highest_blocked;
+	ml->list = queue;
+	if (lock->lksb) {
+		ml->flags = lock->lksb->flags;
+		dlm_prepare_lvb_for_migration(lock, mres, queue);
+	}
+	ml->node = lock->ml.node;
+	mres->num_locks++;
+	/* we reached the max, send this network message */
+	if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
+		return 1;
+	return 0;
+}
+
+static void dlm_add_dummy_lock(struct dlm_ctxt *dlm,
+			       struct dlm_migratable_lockres *mres)
+{
+	struct dlm_lock dummy;
+	memset(&dummy, 0, sizeof(dummy));
+	dummy.ml.cookie = 0;
+	dummy.ml.type = LKM_IVMODE;
+	dummy.ml.convert_type = LKM_IVMODE;
+	dummy.ml.highest_blocked = LKM_IVMODE;
+	dummy.lksb = NULL;
+	dummy.ml.node = dlm->node_num;
+	dlm_add_lock_to_array(&dummy, mres, DLM_BLOCKED_LIST);
+}
+
+static inline int dlm_is_dummy_lock(struct dlm_ctxt *dlm,
+				    struct dlm_migratable_lock *ml,
+				    u8 *nodenum)
+{
+	if (unlikely(ml->cookie == 0 &&
+	    ml->type == LKM_IVMODE &&
+	    ml->convert_type == LKM_IVMODE &&
+	    ml->highest_blocked == LKM_IVMODE &&
+	    ml->list == DLM_BLOCKED_LIST)) {
+		*nodenum = ml->node;
+		return 1;
+	}
+	return 0;
+}
+
+int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
+			 struct dlm_migratable_lockres *mres,
+			 u8 send_to, u8 flags)
+{
+	struct list_head *queue;
+	int total_locks, i;
+	u64 mig_cookie = 0;
+	struct dlm_lock *lock;
+	int ret = 0;
+
+	BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
+
+	mlog(0, "sending to %u\n", send_to);
+
+	total_locks = dlm_num_locks_in_lockres(res);
+	if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
+		/* rare, but possible */
+		mlog(0, "argh.  lockres has %d locks.  this will "
+			  "require more than one network packet to "
+			  "migrate\n", total_locks);
+		mig_cookie = dlm_get_next_mig_cookie();
+	}
+
+	dlm_init_migratable_lockres(mres, res->lockname.name,
+				    res->lockname.len, total_locks,
+				    mig_cookie, flags, res->owner);
+
+	total_locks = 0;
+	for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
+		queue = dlm_list_idx_to_ptr(res, i);
+		list_for_each_entry(lock, queue, list) {
+			/* add another lock. */
+			total_locks++;
+			if (!dlm_add_lock_to_array(lock, mres, i))
+				continue;
+
+			/* this filled the lock message,
+			 * we must send it immediately. */
+			ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
+						       res, total_locks);
+			if (ret < 0)
+				goto error;
+		}
+	}
+	if (total_locks == 0) {
+		/* send a dummy lock to indicate a mastery reference only */
+		mlog(0, "%s:%.*s: sending dummy lock to %u, %s\n",
+		     dlm->name, res->lockname.len, res->lockname.name,
+		     send_to, flags & DLM_MRES_RECOVERY ? "recovery" :
+		     "migration");
+		dlm_add_dummy_lock(dlm, mres);
+	}
+	/* flush any remaining locks */
+	ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
+	if (ret < 0)
+		goto error;
+	return ret;
+
+error:
+	mlog(ML_ERROR, "%s: dlm_send_mig_lockres_msg returned %d\n",
+	     dlm->name, ret);
+	if (!dlm_is_host_down(ret))
+		BUG();
+	mlog(0, "%s: node %u went down while sending %s "
+	     "lockres %.*s\n", dlm->name, send_to,
+	     flags & DLM_MRES_RECOVERY ?  "recovery" : "migration",
+	     res->lockname.len, res->lockname.name);
+	return ret;
+}
+
+
+
+/*
+ * this message will contain no more than one page worth of
+ * recovery data, and it will work on only one lockres.
+ * there may be many locks in this page, and we may need to wait
+ * for additional packets to complete all the locks (rare, but
+ * possible).
+ */
+/*
+ * NOTE: the allocation error cases here are scary
+ * we really cannot afford to fail an alloc in recovery
+ * do we spin?  returning an error only delays the problem really
+ */
+
+int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
+			    void **ret_data)
+{
+	struct dlm_ctxt *dlm = data;
+	struct dlm_migratable_lockres *mres =
+		(struct dlm_migratable_lockres *)msg->buf;
+	int ret = 0;
+	u8 real_master;
+	u8 extra_refs = 0;
+	char *buf = NULL;
+	struct dlm_work_item *item = NULL;
+	struct dlm_lock_resource *res = NULL;
+	unsigned int hash;
+
+	if (!dlm_grab(dlm))
+		return -EINVAL;
+
+	if (!dlm_joined(dlm)) {
+		mlog(ML_ERROR, "Domain %s not joined! "
+			  "lockres %.*s, master %u\n",
+			  dlm->name, mres->lockname_len,
+			  mres->lockname, mres->master);
+		dlm_put(dlm);
+		return -EINVAL;
+	}
+
+	BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
+
+	real_master = mres->master;
+	if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
+		/* cannot migrate a lockres with no master */
+		BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
+	}
+
+	mlog(0, "%s message received from node %u\n",
+		  (mres->flags & DLM_MRES_RECOVERY) ?
+		  "recovery" : "migration", mres->master);
+	if (mres->flags & DLM_MRES_ALL_DONE)
+		mlog(0, "all done flag.  all lockres data received!\n");
+
+	ret = -ENOMEM;
+	buf = kmalloc(be16_to_cpu(msg->data_len), GFP_NOFS);
+	item = kzalloc(sizeof(*item), GFP_NOFS);
+	if (!buf || !item)
+		goto leave;
+
+	/* lookup the lock to see if we have a secondary queue for this
+	 * already...  just add the locks in and this will have its owner
+	 * and RECOVERY flag changed when it completes. */
+	hash = dlm_lockid_hash(mres->lockname, mres->lockname_len);
+	spin_lock(&dlm->spinlock);
+	res = __dlm_lookup_lockres_full(dlm, mres->lockname, mres->lockname_len,
+			hash);
+	if (res) {
+	 	/* this will get a ref on res */
+		/* mark it as recovering/migrating and hash it */
+		spin_lock(&res->spinlock);
+		if (res->state & DLM_LOCK_RES_DROPPING_REF) {
+			mlog(0, "%s: node is attempting to migrate "
+				"lockres %.*s, but marked as dropping "
+				" ref!\n", dlm->name,
+				mres->lockname_len, mres->lockname);
+			ret = -EINVAL;
+			spin_unlock(&res->spinlock);
+			spin_unlock(&dlm->spinlock);
+			dlm_lockres_put(res);
+			goto leave;
+		}
+
+		if (mres->flags & DLM_MRES_RECOVERY) {
+			res->state |= DLM_LOCK_RES_RECOVERING;
+		} else {
+			if (res->state & DLM_LOCK_RES_MIGRATING) {
+				/* this is at least the second
+				 * lockres message */
+				mlog(0, "lock %.*s is already migrating\n",
+					  mres->lockname_len,
+					  mres->lockname);
+			} else if (res->state & DLM_LOCK_RES_RECOVERING) {
+				/* caller should BUG */
+				mlog(ML_ERROR, "node is attempting to migrate "
+				     "lock %.*s, but marked as recovering!\n",
+				     mres->lockname_len, mres->lockname);
+				ret = -EFAULT;
+				spin_unlock(&res->spinlock);
+				spin_unlock(&dlm->spinlock);
+				dlm_lockres_put(res);
+				goto leave;
+			}
+			res->state |= DLM_LOCK_RES_MIGRATING;
+		}
+		spin_unlock(&res->spinlock);
+		spin_unlock(&dlm->spinlock);
+	} else {
+		spin_unlock(&dlm->spinlock);
+		/* need to allocate, just like if it was
+		 * mastered here normally  */
+		res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
+		if (!res)
+			goto leave;
+
+		/* to match the ref that we would have gotten if
+		 * dlm_lookup_lockres had succeeded */
+		dlm_lockres_get(res);
+
+		/* mark it as recovering/migrating and hash it */
+		if (mres->flags & DLM_MRES_RECOVERY)
+			res->state |= DLM_LOCK_RES_RECOVERING;
+		else
+			res->state |= DLM_LOCK_RES_MIGRATING;
+
+		spin_lock(&dlm->spinlock);
+		__dlm_insert_lockres(dlm, res);
+		spin_unlock(&dlm->spinlock);
+
+		/* Add an extra ref for this lock-less lockres lest the
+		 * dlm_thread purges it before we get the chance to add
+		 * locks to it */
+		dlm_lockres_get(res);
+
+		/* There are three refs that need to be put.
+		 * 1. Taken above.
+		 * 2. kref_init in dlm_new_lockres()->dlm_init_lockres().
+		 * 3. dlm_lookup_lockres()
+		 * The first one is handled at the end of this function. The
+		 * other two are handled in the worker thread after locks have
+		 * been attached. Yes, we don't wait for purge time to match
+		 * kref_init. The lockres will still have atleast one ref
+		 * added because it is in the hash __dlm_insert_lockres() */
+		extra_refs++;
+
+		/* now that the new lockres is inserted,
+		 * make it usable by other processes */
+		spin_lock(&res->spinlock);
+		res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
+		spin_unlock(&res->spinlock);
+		wake_up(&res->wq);
+	}
+
+	/* at this point we have allocated everything we need,
+	 * and we have a hashed lockres with an extra ref and
+	 * the proper res->state flags. */
+	ret = 0;
+	spin_lock(&res->spinlock);
+	/* drop this either when master requery finds a different master
+	 * or when a lock is added by the recovery worker */
+	dlm_lockres_grab_inflight_ref(dlm, res);
+	if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
+		/* migration cannot have an unknown master */
+		BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
+		mlog(0, "recovery has passed me a lockres with an "
+			  "unknown owner.. will need to requery: "
+			  "%.*s\n", mres->lockname_len, mres->lockname);
+	} else {
+		/* take a reference now to pin the lockres, drop it
+		 * when locks are added in the worker */
+		dlm_change_lockres_owner(dlm, res, dlm->node_num);
+	}
+	spin_unlock(&res->spinlock);
+
+	/* queue up work for dlm_mig_lockres_worker */
+	dlm_grab(dlm);  /* get an extra ref for the work item */
+	memcpy(buf, msg->buf, be16_to_cpu(msg->data_len));  /* copy the whole message */
+	dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
+	item->u.ml.lockres = res; /* already have a ref */
+	item->u.ml.real_master = real_master;
+	item->u.ml.extra_ref = extra_refs;
+	spin_lock(&dlm->work_lock);
+	list_add_tail(&item->list, &dlm->work_list);
+	spin_unlock(&dlm->work_lock);
+	queue_work(dlm->dlm_worker, &dlm->dispatched_work);
+
+leave:
+	/* One extra ref taken needs to be put here */
+	if (extra_refs)
+		dlm_lockres_put(res);
+
+	dlm_put(dlm);
+	if (ret < 0) {
+		kfree(buf);
+		kfree(item);
+		mlog_errno(ret);
+	}
+
+	return ret;
+}
+
+
+static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
+{
+	struct dlm_ctxt *dlm;
+	struct dlm_migratable_lockres *mres;
+	int ret = 0;
+	struct dlm_lock_resource *res;
+	u8 real_master;
+	u8 extra_ref;
+
+	dlm = item->dlm;
+	mres = (struct dlm_migratable_lockres *)data;
+
+	res = item->u.ml.lockres;
+	real_master = item->u.ml.real_master;
+	extra_ref = item->u.ml.extra_ref;
+
+	if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
+		/* this case is super-rare. only occurs if
+		 * node death happens during migration. */
+again:
+		ret = dlm_lockres_master_requery(dlm, res, &real_master);
+		if (ret < 0) {
+			mlog(0, "dlm_lockres_master_requery ret=%d\n",
+				  ret);
+			goto again;
+		}
+		if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
+			mlog(0, "lockres %.*s not claimed.  "
+				   "this node will take it.\n",
+				   res->lockname.len, res->lockname.name);
+		} else {
+			spin_lock(&res->spinlock);
+			dlm_lockres_drop_inflight_ref(dlm, res);
+			spin_unlock(&res->spinlock);
+			mlog(0, "master needs to respond to sender "
+				  "that node %u still owns %.*s\n",
+				  real_master, res->lockname.len,
+				  res->lockname.name);
+			/* cannot touch this lockres */
+			goto leave;
+		}
+	}
+
+	ret = dlm_process_recovery_data(dlm, res, mres);
+	if (ret < 0)
+		mlog(0, "dlm_process_recovery_data returned  %d\n", ret);
+	else
+		mlog(0, "dlm_process_recovery_data succeeded\n");
+
+	if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
+	                   (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
+		ret = dlm_finish_migration(dlm, res, mres->master);
+		if (ret < 0)
+			mlog_errno(ret);
+	}
+
+leave:
+	/* See comment in dlm_mig_lockres_handler() */
+	if (res) {
+		if (extra_ref)
+			dlm_lockres_put(res);
+		dlm_lockres_put(res);
+	}
+	kfree(data);
+}
+
+
+
+static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
+				      struct dlm_lock_resource *res,
+				      u8 *real_master)
+{
+	struct dlm_node_iter iter;
+	int nodenum;
+	int ret = 0;
+
+	*real_master = DLM_LOCK_RES_OWNER_UNKNOWN;
+
+	/* we only reach here if one of the two nodes in a
+	 * migration died while the migration was in progress.
+	 * at this point we need to requery the master.  we
+	 * know that the new_master got as far as creating
+	 * an mle on at least one node, but we do not know
+	 * if any nodes had actually cleared the mle and set
+	 * the master to the new_master.  the old master
+	 * is supposed to set the owner to UNKNOWN in the
+	 * event of a new_master death, so the only possible
+	 * responses that we can get from nodes here are
+	 * that the master is new_master, or that the master
+	 * is UNKNOWN.
+	 * if all nodes come back with UNKNOWN then we know
+	 * the lock needs remastering here.
+	 * if any node comes back with a valid master, check
+	 * to see if that master is the one that we are
+	 * recovering.  if so, then the new_master died and
+	 * we need to remaster this lock.  if not, then the
+	 * new_master survived and that node will respond to
+	 * other nodes about the owner.
+	 * if there is an owner, this node needs to dump this
+	 * lockres and alert the sender that this lockres
+	 * was rejected. */
+	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, real_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 (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
+			mlog(0, "lock master is %u\n", *real_master);
+			break;
+		}
+	}
+	return ret;
+}
+
+
+int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
+			  u8 nodenum, u8 *real_master)
+{
+	int ret;
+	struct dlm_master_requery req;
+	int status = DLM_LOCK_RES_OWNER_UNKNOWN;
+
+	memset(&req, 0, sizeof(req));
+	req.node_idx = dlm->node_num;
+	req.namelen = res->lockname.len;
+	memcpy(req.name, res->lockname.name, res->lockname.len);
+
+resend:
+	ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
+				 &req, sizeof(req), nodenum, &status);
+	if (ret < 0)
+		mlog(ML_ERROR, "Error %d when sending message %u (key "
+		     "0x%x) to node %u\n", ret, DLM_MASTER_REQUERY_MSG,
+		     dlm->key, nodenum);
+	else if (status == -ENOMEM) {
+		mlog_errno(status);
+		msleep(50);
+		goto resend;
+	} else {
+		BUG_ON(status < 0);
+		BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
+		*real_master = (u8) (status & 0xff);
+		mlog(0, "node %u responded to master requery with %u\n",
+			  nodenum, *real_master);
+		ret = 0;
+	}
+	return ret;
+}
+
+
+/* this function cannot error, so unless the sending
+ * or receiving of the message failed, the owner can
+ * be trusted */
+int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
+			       void **ret_data)
+{
+	struct dlm_ctxt *dlm = data;
+	struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
+	struct dlm_lock_resource *res = NULL;
+	unsigned int hash;
+	int master = DLM_LOCK_RES_OWNER_UNKNOWN;
+	u32 flags = DLM_ASSERT_MASTER_REQUERY;
+	int dispatched = 0;
+
+	if (!dlm_grab(dlm)) {
+		/* since the domain has gone away on this
+		 * node, the proper response is UNKNOWN */
+		return master;
+	}
+
+	hash = dlm_lockid_hash(req->name, req->namelen);
+
+	spin_lock(&dlm->spinlock);
+	res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
+	if (res) {
+		spin_lock(&res->spinlock);
+		master = res->owner;
+		if (master == dlm->node_num) {
+			int ret = dlm_dispatch_assert_master(dlm, res,
+							     0, 0, flags);
+			if (ret < 0) {
+				mlog_errno(ret);
+				spin_unlock(&res->spinlock);
+				dlm_lockres_put(res);
+				spin_unlock(&dlm->spinlock);
+				dlm_put(dlm);
+				/* sender will take care of this and retry */
+				return ret;
+			} else {
+				dispatched = 1;
+				__dlm_lockres_grab_inflight_worker(dlm, res);
+				spin_unlock(&res->spinlock);
+			}
+		} else {
+			/* put.. incase we are not the master */
+			spin_unlock(&res->spinlock);
+			dlm_lockres_put(res);
+		}
+	}
+	spin_unlock(&dlm->spinlock);
+
+	if (!dispatched)
+		dlm_put(dlm);
+	return master;
+}
+
+static inline struct list_head *
+dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
+{
+	struct list_head *ret;
+	BUG_ON(list_num < 0);
+	BUG_ON(list_num > 2);
+	ret = &(res->granted);
+	ret += list_num;
+	return ret;
+}
+/* TODO: do ast flush business
+ * TODO: do MIGRATING and RECOVERING spinning
+ */
+
+/*
+* NOTE about in-flight requests during migration:
+*
+* Before attempting the migrate, the master has marked the lockres as
+* MIGRATING and then flushed all of its pending ASTS.  So any in-flight
+* requests either got queued before the MIGRATING flag got set, in which
+* case the lock data will reflect the change and a return message is on
+* the way, or the request failed to get in before MIGRATING got set.  In
+* this case, the caller will be told to spin and wait for the MIGRATING
+* flag to be dropped, then recheck the master.
+* This holds true for the convert, cancel and unlock cases, and since lvb
+* updates are tied to these same messages, it applies to lvb updates as
+* well.  For the lock case, there is no way a lock can be on the master
+* queue and not be on the secondary queue since the lock is always added
+* locally first.  This means that the new target node will never be sent
+* a lock that he doesn't already have on the list.
+* In total, this means that the local lock is correct and should not be
+* updated to match the one sent by the master.  Any messages sent back
+* from the master before the MIGRATING flag will bring the lock properly
+* up-to-date, and the change will be ordered properly for the waiter.
+* We will *not* attempt to modify the lock underneath the waiter.
+*/
+
+static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
+				     struct dlm_lock_resource *res,
+				     struct dlm_migratable_lockres *mres)
+{
+	struct dlm_migratable_lock *ml;
+	struct list_head *queue, *iter;
+	struct list_head *tmpq = NULL;
+	struct dlm_lock *newlock = NULL;
+	struct dlm_lockstatus *lksb = NULL;
+	int ret = 0;
+	int i, j, bad;
+	struct dlm_lock *lock;
+	u8 from = O2NM_MAX_NODES;
+	__be64 c;
+
+	mlog(0, "running %d locks for this lockres\n", mres->num_locks);
+	for (i=0; i<mres->num_locks; i++) {
+		ml = &(mres->ml[i]);
+
+		if (dlm_is_dummy_lock(dlm, ml, &from)) {
+			/* placeholder, just need to set the refmap bit */
+			BUG_ON(mres->num_locks != 1);
+			mlog(0, "%s:%.*s: dummy lock for %u\n",
+			     dlm->name, mres->lockname_len, mres->lockname,
+			     from);
+			spin_lock(&res->spinlock);
+			dlm_lockres_set_refmap_bit(dlm, res, from);
+			spin_unlock(&res->spinlock);
+			break;
+		}
+		BUG_ON(ml->highest_blocked != LKM_IVMODE);
+		newlock = NULL;
+		lksb = NULL;
+
+		queue = dlm_list_num_to_pointer(res, ml->list);
+		tmpq = NULL;
+
+		/* if the lock is for the local node it needs to
+		 * be moved to the proper location within the queue.
+		 * do not allocate a new lock structure. */
+		if (ml->node == dlm->node_num) {
+			/* MIGRATION ONLY! */
+			BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));
+
+			lock = NULL;
+			spin_lock(&res->spinlock);
+			for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
+				tmpq = dlm_list_idx_to_ptr(res, j);
+				list_for_each(iter, tmpq) {
+					lock = list_entry(iter,
+						  struct dlm_lock, list);
+					if (lock->ml.cookie == ml->cookie)
+						break;
+					lock = NULL;
+				}
+				if (lock)
+					break;
+			}
+
+			/* lock is always created locally first, and
+			 * destroyed locally last.  it must be on the list */
+			if (!lock) {
+				c = ml->cookie;
+				mlog(ML_ERROR, "Could not find local lock "
+					       "with cookie %u:%llu, node %u, "
+					       "list %u, flags 0x%x, type %d, "
+					       "conv %d, highest blocked %d\n",
+				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
+				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
+				     ml->node, ml->list, ml->flags, ml->type,
+				     ml->convert_type, ml->highest_blocked);
+				__dlm_print_one_lock_resource(res);
+				BUG();
+			}
+
+			if (lock->ml.node != ml->node) {
+				c = lock->ml.cookie;
+				mlog(ML_ERROR, "Mismatched node# in lock "
+				     "cookie %u:%llu, name %.*s, node %u\n",
+				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
+				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
+				     res->lockname.len, res->lockname.name,
+				     lock->ml.node);
+				c = ml->cookie;
+				mlog(ML_ERROR, "Migrate lock cookie %u:%llu, "
+				     "node %u, list %u, flags 0x%x, type %d, "
+				     "conv %d, highest blocked %d\n",
+				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
+				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
+				     ml->node, ml->list, ml->flags, ml->type,
+				     ml->convert_type, ml->highest_blocked);
+				__dlm_print_one_lock_resource(res);
+				BUG();
+			}
+
+			if (tmpq != queue) {
+				c = ml->cookie;
+				mlog(0, "Lock cookie %u:%llu was on list %u "
+				     "instead of list %u for %.*s\n",
+				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
+				     dlm_get_lock_cookie_seq(be64_to_cpu(c)),
+				     j, ml->list, res->lockname.len,
+				     res->lockname.name);
+				__dlm_print_one_lock_resource(res);
+				spin_unlock(&res->spinlock);
+				continue;
+			}
+
+			/* see NOTE above about why we do not update
+			 * to match the master here */
+
+			/* move the lock to its proper place */
+			/* do not alter lock refcount.  switching lists. */
+			list_move_tail(&lock->list, queue);
+			spin_unlock(&res->spinlock);
+
+			mlog(0, "just reordered a local lock!\n");
+			continue;
+		}
+
+		/* lock is for another node. */
+		newlock = dlm_new_lock(ml->type, ml->node,
+				       be64_to_cpu(ml->cookie), NULL);
+		if (!newlock) {
+			ret = -ENOMEM;
+			goto leave;
+		}
+		lksb = newlock->lksb;
+		dlm_lock_attach_lockres(newlock, res);
+
+		if (ml->convert_type != LKM_IVMODE) {
+			BUG_ON(queue != &res->converting);
+			newlock->ml.convert_type = ml->convert_type;
+		}
+		lksb->flags |= (ml->flags &
+				(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
+
+		if (ml->type == LKM_NLMODE)
+			goto skip_lvb;
+
+		/*
+		 * If the lock is in the blocked list it can't have a valid lvb,
+		 * so skip it
+		 */
+		if (ml->list == DLM_BLOCKED_LIST)
+			goto skip_lvb;
+
+		if (!dlm_lvb_is_empty(mres->lvb)) {
+			if (lksb->flags & DLM_LKSB_PUT_LVB) {
+				/* other node was trying to update
+				 * lvb when node died.  recreate the
+				 * lksb with the updated lvb. */
+				memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
+				/* the lock resource lvb update must happen
+				 * NOW, before the spinlock is dropped.
+				 * we no longer wait for the AST to update
+				 * the lvb. */
+				memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
+			} else {
+				/* otherwise, the node is sending its
+				 * most recent valid lvb info */
+				BUG_ON(ml->type != LKM_EXMODE &&
+				       ml->type != LKM_PRMODE);
+				if (!dlm_lvb_is_empty(res->lvb) &&
+ 				    (ml->type == LKM_EXMODE ||
+ 				     memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
+ 					int i;
+ 					mlog(ML_ERROR, "%s:%.*s: received bad "
+ 					     "lvb! type=%d\n", dlm->name,
+ 					     res->lockname.len,
+ 					     res->lockname.name, ml->type);
+ 					printk("lockres lvb=[");
+ 					for (i=0; i<DLM_LVB_LEN; i++)
+ 						printk("%02x", res->lvb[i]);
+ 					printk("]\nmigrated lvb=[");
+ 					for (i=0; i<DLM_LVB_LEN; i++)
+ 						printk("%02x", mres->lvb[i]);
+ 					printk("]\n");
+ 					dlm_print_one_lock_resource(res);
+ 					BUG();
+				}
+				memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
+			}
+		}
+skip_lvb:
+
+		/* NOTE:
+		 * wrt lock queue ordering and recovery:
+		 *    1. order of locks on granted queue is
+		 *       meaningless.
+		 *    2. order of locks on converting queue is
+		 *       LOST with the node death.  sorry charlie.
+		 *    3. order of locks on the blocked queue is
+		 *       also LOST.
+		 * order of locks does not affect integrity, it
+		 * just means that a lock request may get pushed
+		 * back in line as a result of the node death.
+		 * also note that for a given node the lock order
+		 * for its secondary queue locks is preserved
+		 * relative to each other, but clearly *not*
+		 * preserved relative to locks from other nodes.
+		 */
+		bad = 0;
+		spin_lock(&res->spinlock);
+		list_for_each_entry(lock, queue, list) {
+			if (lock->ml.cookie == ml->cookie) {
+				c = lock->ml.cookie;
+				mlog(ML_ERROR, "%s:%.*s: %u:%llu: lock already "
+				     "exists on this lockres!\n", dlm->name,
+				     res->lockname.len, res->lockname.name,
+				     dlm_get_lock_cookie_node(be64_to_cpu(c)),
+				     dlm_get_lock_cookie_seq(be64_to_cpu(c)));
+
+				mlog(ML_NOTICE, "sent lock: type=%d, conv=%d, "
+				     "node=%u, cookie=%u:%llu, queue=%d\n",
+	      			     ml->type, ml->convert_type, ml->node,
+				     dlm_get_lock_cookie_node(be64_to_cpu(ml->cookie)),
+				     dlm_get_lock_cookie_seq(be64_to_cpu(ml->cookie)),
+				     ml->list);
+
+				__dlm_print_one_lock_resource(res);
+				bad = 1;
+				break;
+			}
+		}
+		if (!bad) {
+			dlm_lock_get(newlock);
+			if (mres->flags & DLM_MRES_RECOVERY &&
+					ml->list == DLM_CONVERTING_LIST &&
+					newlock->ml.type >
+					newlock->ml.convert_type) {
+				/* newlock is doing downconvert, add it to the
+				 * head of converting list */
+				list_add(&newlock->list, queue);
+			} else
+				list_add_tail(&newlock->list, queue);
+			mlog(0, "%s:%.*s: added lock for node %u, "
+			     "setting refmap bit\n", dlm->name,
+			     res->lockname.len, res->lockname.name, ml->node);
+			dlm_lockres_set_refmap_bit(dlm, res, ml->node);
+		}
+		spin_unlock(&res->spinlock);
+	}
+	mlog(0, "done running all the locks\n");
+
+leave:
+	/* balance the ref taken when the work was queued */
+	spin_lock(&res->spinlock);
+	dlm_lockres_drop_inflight_ref(dlm, res);
+	spin_unlock(&res->spinlock);
+
+	if (ret < 0)
+		mlog_errno(ret);
+
+	return ret;
+}
+
+void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
+				       struct dlm_lock_resource *res)
+{
+	int i;
+	struct list_head *queue;
+	struct dlm_lock *lock, *next;
+
+	assert_spin_locked(&dlm->spinlock);
+	assert_spin_locked(&res->spinlock);
+	res->state |= DLM_LOCK_RES_RECOVERING;
+	if (!list_empty(&res->recovering)) {
+		mlog(0,
+		     "Recovering res %s:%.*s, is already on recovery list!\n",
+		     dlm->name, res->lockname.len, res->lockname.name);
+		list_del_init(&res->recovering);
+		dlm_lockres_put(res);
+	}
+	/* We need to hold a reference while on the recovery list */
+	dlm_lockres_get(res);
+	list_add_tail(&res->recovering, &dlm->reco.resources);
+
+	/* find any pending locks and put them back on proper list */
+	for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
+		queue = dlm_list_idx_to_ptr(res, i);
+		list_for_each_entry_safe(lock, next, queue, list) {
+			dlm_lock_get(lock);
+			if (lock->convert_pending) {
+				/* move converting lock back to granted */
+				mlog(0, "node died with convert pending "
+				     "on %.*s. move back to granted list.\n",
+				     res->lockname.len, res->lockname.name);
+				dlm_revert_pending_convert(res, lock);
+				lock->convert_pending = 0;
+			} else if (lock->lock_pending) {
+				/* remove pending lock requests completely */
+				BUG_ON(i != DLM_BLOCKED_LIST);
+				mlog(0, "node died with lock pending "
+				     "on %.*s. remove from blocked list and skip.\n",
+				     res->lockname.len, res->lockname.name);
+				/* lock will be floating until ref in
+				 * dlmlock_remote is freed after the network
+				 * call returns.  ok for it to not be on any
+				 * list since no ast can be called
+				 * (the master is dead). */
+				dlm_revert_pending_lock(res, lock);
+				lock->lock_pending = 0;
+			} else if (lock->unlock_pending) {
+				/* if an unlock was in progress, treat as
+				 * if this had completed successfully
+				 * before sending this lock state to the
+				 * new master.  note that the dlm_unlock
+				 * call is still responsible for calling
+				 * the unlockast.  that will happen after
+				 * the network call times out.  for now,
+				 * just move lists to prepare the new
+				 * recovery master.  */
+				BUG_ON(i != DLM_GRANTED_LIST);
+				mlog(0, "node died with unlock pending "
+				     "on %.*s. remove from blocked list and skip.\n",
+				     res->lockname.len, res->lockname.name);
+				dlm_commit_pending_unlock(res, lock);
+				lock->unlock_pending = 0;
+			} else if (lock->cancel_pending) {
+				/* if a cancel was in progress, treat as
+				 * if this had completed successfully
+				 * before sending this lock state to the
+				 * new master */
+				BUG_ON(i != DLM_CONVERTING_LIST);
+				mlog(0, "node died with cancel pending "
+				     "on %.*s. move back to granted list.\n",
+				     res->lockname.len, res->lockname.name);
+				dlm_commit_pending_cancel(res, lock);
+				lock->cancel_pending = 0;
+			}
+			dlm_lock_put(lock);
+		}
+	}
+}
+
+
+
+/* removes all recovered locks from the recovery list.
+ * sets the res->owner to the new master.
+ * unsets the RECOVERY flag and wakes waiters. */
+static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
+					      u8 dead_node, u8 new_master)
+{
+	int i;
+	struct hlist_head *bucket;
+	struct dlm_lock_resource *res, *next;
+
+	assert_spin_locked(&dlm->spinlock);
+
+	list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
+		if (res->owner == dead_node) {
+			mlog(0, "%s: res %.*s, Changing owner from %u to %u\n",
+			     dlm->name, res->lockname.len, res->lockname.name,
+			     res->owner, new_master);
+			list_del_init(&res->recovering);
+			spin_lock(&res->spinlock);
+			/* new_master has our reference from
+			 * the lock state sent during recovery */
+			dlm_change_lockres_owner(dlm, res, new_master);
+			res->state &= ~DLM_LOCK_RES_RECOVERING;
+			if (__dlm_lockres_has_locks(res))
+				__dlm_dirty_lockres(dlm, res);
+			spin_unlock(&res->spinlock);
+			wake_up(&res->wq);
+			dlm_lockres_put(res);
+		}
+	}
+
+	/* this will become unnecessary eventually, but
+	 * for now we need to run the whole hash, clear
+	 * the RECOVERING state and set the owner
+	 * if necessary */
+	for (i = 0; i < DLM_HASH_BUCKETS; i++) {
+		bucket = dlm_lockres_hash(dlm, i);
+		hlist_for_each_entry(res, bucket, hash_node) {
+			if (res->state & DLM_LOCK_RES_RECOVERY_WAITING) {
+				spin_lock(&res->spinlock);
+				res->state &= ~DLM_LOCK_RES_RECOVERY_WAITING;
+				spin_unlock(&res->spinlock);
+				wake_up(&res->wq);
+			}
+
+			if (!(res->state & DLM_LOCK_RES_RECOVERING))
+				continue;
+
+			if (res->owner != dead_node &&
+			    res->owner != dlm->node_num)
+				continue;
+
+			if (!list_empty(&res->recovering)) {
+				list_del_init(&res->recovering);
+				dlm_lockres_put(res);
+			}
+
+			/* new_master has our reference from
+			 * the lock state sent during recovery */
+			mlog(0, "%s: res %.*s, Changing owner from %u to %u\n",
+			     dlm->name, res->lockname.len, res->lockname.name,
+			     res->owner, new_master);
+			spin_lock(&res->spinlock);
+			dlm_change_lockres_owner(dlm, res, new_master);
+			res->state &= ~DLM_LOCK_RES_RECOVERING;
+			if (__dlm_lockres_has_locks(res))
+				__dlm_dirty_lockres(dlm, res);
+			spin_unlock(&res->spinlock);
+			wake_up(&res->wq);
+		}
+	}
+}
+
+static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
+{
+	if (local) {
+		if (lock->ml.type != LKM_EXMODE &&
+		    lock->ml.type != LKM_PRMODE)
+			return 1;
+	} else if (lock->ml.type == LKM_EXMODE)
+		return 1;
+	return 0;
+}
+
+static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
+			       struct dlm_lock_resource *res, u8 dead_node)
+{
+	struct list_head *queue;
+	struct dlm_lock *lock;
+	int blank_lvb = 0, local = 0;
+	int i;
+	u8 search_node;
+
+	assert_spin_locked(&dlm->spinlock);
+	assert_spin_locked(&res->spinlock);
+
+	if (res->owner == dlm->node_num)
+		/* if this node owned the lockres, and if the dead node
+		 * had an EX when he died, blank out the lvb */
+		search_node = dead_node;
+	else {
+		/* if this is a secondary lockres, and we had no EX or PR
+		 * locks granted, we can no longer trust the lvb */
+		search_node = dlm->node_num;
+		local = 1;  /* check local state for valid lvb */
+	}
+
+	for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
+		queue = dlm_list_idx_to_ptr(res, i);
+		list_for_each_entry(lock, queue, list) {
+			if (lock->ml.node == search_node) {
+				if (dlm_lvb_needs_invalidation(lock, local)) {
+					/* zero the lksb lvb and lockres lvb */
+					blank_lvb = 1;
+					memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
+				}
+			}
+		}
+	}
+
+	if (blank_lvb) {
+		mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
+		     res->lockname.len, res->lockname.name, dead_node);
+		memset(res->lvb, 0, DLM_LVB_LEN);
+	}
+}
+
+static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
+				struct dlm_lock_resource *res, u8 dead_node)
+{
+	struct dlm_lock *lock, *next;
+	unsigned int freed = 0;
+
+	/* this node is the lockres master:
+	 * 1) remove any stale locks for the dead node
+	 * 2) if the dead node had an EX when he died, blank out the lvb
+	 */
+	assert_spin_locked(&dlm->spinlock);
+	assert_spin_locked(&res->spinlock);
+
+	/* We do two dlm_lock_put(). One for removing from list and the other is
+	 * to force the DLM_UNLOCK_FREE_LOCK action so as to free the locks */
+
+	/* TODO: check pending_asts, pending_basts here */
+	list_for_each_entry_safe(lock, next, &res->granted, list) {
+		if (lock->ml.node == dead_node) {
+			list_del_init(&lock->list);
+			dlm_lock_put(lock);
+			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
+			dlm_lock_put(lock);
+			freed++;
+		}
+	}
+	list_for_each_entry_safe(lock, next, &res->converting, list) {
+		if (lock->ml.node == dead_node) {
+			list_del_init(&lock->list);
+			dlm_lock_put(lock);
+			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
+			dlm_lock_put(lock);
+			freed++;
+		}
+	}
+	list_for_each_entry_safe(lock, next, &res->blocked, list) {
+		if (lock->ml.node == dead_node) {
+			list_del_init(&lock->list);
+			dlm_lock_put(lock);
+			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
+			dlm_lock_put(lock);
+			freed++;
+		}
+	}
+
+	if (freed) {
+		mlog(0, "%s:%.*s: freed %u locks for dead node %u, "
+		     "dropping ref from lockres\n", dlm->name,
+		     res->lockname.len, res->lockname.name, freed, dead_node);
+		if(!test_bit(dead_node, res->refmap)) {
+			mlog(ML_ERROR, "%s:%.*s: freed %u locks for dead node %u, "
+			     "but ref was not set\n", dlm->name,
+			     res->lockname.len, res->lockname.name, freed, dead_node);
+			__dlm_print_one_lock_resource(res);
+		}
+		res->state |= DLM_LOCK_RES_RECOVERY_WAITING;
+		dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
+	} else if (test_bit(dead_node, res->refmap)) {
+		mlog(0, "%s:%.*s: dead node %u had a ref, but had "
+		     "no locks and had not purged before dying\n", dlm->name,
+		     res->lockname.len, res->lockname.name, dead_node);
+		dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
+	}
+
+	/* do not kick thread yet */
+	__dlm_dirty_lockres(dlm, res);
+}
+
+static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
+{
+	struct dlm_lock_resource *res;
+	int i;
+	struct hlist_head *bucket;
+	struct hlist_node *tmp;
+	struct dlm_lock *lock;
+
+
+	/* purge any stale mles */
+	dlm_clean_master_list(dlm, dead_node);
+
+	/*
+	 * now clean up all lock resources.  there are two rules:
+	 *
+	 * 1) if the dead node was the master, move the lockres
+	 *    to the recovering list.  set the RECOVERING flag.
+	 *    this lockres needs to be cleaned up before it can
+	 *    be used further.
+	 *
+	 * 2) if this node was the master, remove all locks from
+	 *    each of the lockres queues that were owned by the
+	 *    dead node.  once recovery finishes, the dlm thread
+	 *    can be kicked again to see if any ASTs or BASTs
+	 *    need to be fired as a result.
+	 */
+	for (i = 0; i < DLM_HASH_BUCKETS; i++) {
+		bucket = dlm_lockres_hash(dlm, i);
+		hlist_for_each_entry_safe(res, tmp, bucket, hash_node) {
+ 			/* always prune any $RECOVERY entries for dead nodes,
+ 			 * otherwise hangs can occur during later recovery */
+			if (dlm_is_recovery_lock(res->lockname.name,
+						 res->lockname.len)) {
+				spin_lock(&res->spinlock);
+				list_for_each_entry(lock, &res->granted, list) {
+					if (lock->ml.node == dead_node) {
+						mlog(0, "AHA! there was "
+						     "a $RECOVERY lock for dead "
+						     "node %u (%s)!\n",
+						     dead_node, dlm->name);
+						list_del_init(&lock->list);
+						dlm_lock_put(lock);
+						/* Can't schedule
+						 * DLM_UNLOCK_FREE_LOCK
+						 * - do manually */
+						dlm_lock_put(lock);
+						break;
+					}
+				}
+
+				if ((res->owner == dead_node) &&
+							(res->state & DLM_LOCK_RES_DROPPING_REF)) {
+					dlm_lockres_get(res);
+					__dlm_do_purge_lockres(dlm, res);
+					spin_unlock(&res->spinlock);
+					wake_up(&res->wq);
+					dlm_lockres_put(res);
+					continue;
+				} else if (res->owner == dlm->node_num)
+					dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
+				spin_unlock(&res->spinlock);
+				continue;
+			}
+			spin_lock(&res->spinlock);
+			/* zero the lvb if necessary */
+			dlm_revalidate_lvb(dlm, res, dead_node);
+			if (res->owner == dead_node) {
+				if (res->state & DLM_LOCK_RES_DROPPING_REF) {
+					mlog(0, "%s:%.*s: owned by "
+						"dead node %u, this node was "
+						"dropping its ref when master died. "
+						"continue, purging the lockres.\n",
+						dlm->name, res->lockname.len,
+						res->lockname.name, dead_node);
+					dlm_lockres_get(res);
+					__dlm_do_purge_lockres(dlm, res);
+					spin_unlock(&res->spinlock);
+					wake_up(&res->wq);
+					dlm_lockres_put(res);
+					continue;
+				}
+				dlm_move_lockres_to_recovery_list(dlm, res);
+			} else if (res->owner == dlm->node_num) {
+				dlm_free_dead_locks(dlm, res, dead_node);
+				__dlm_lockres_calc_usage(dlm, res);
+			} else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
+				if (test_bit(dead_node, res->refmap)) {
+					mlog(0, "%s:%.*s: dead node %u had a ref, but had "
+						"no locks and had not purged before dying\n",
+						dlm->name, res->lockname.len,
+						res->lockname.name, dead_node);
+					dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
+				}
+			}
+			spin_unlock(&res->spinlock);
+		}
+	}
+
+}
+
+static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
+{
+	assert_spin_locked(&dlm->spinlock);
+
+	if (dlm->reco.new_master == idx) {
+		mlog(0, "%s: recovery master %d just died\n",
+		     dlm->name, idx);
+		if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
+			/* finalize1 was reached, so it is safe to clear
+			 * the new_master and dead_node.  that recovery
+			 * is complete. */
+			mlog(0, "%s: dead master %d had reached "
+			     "finalize1 state, clearing\n", dlm->name, idx);
+			dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
+			__dlm_reset_recovery(dlm);
+		}
+	}
+
+	/* Clean up join state on node death. */
+	if (dlm->joining_node == idx) {
+		mlog(0, "Clearing join state for node %u\n", idx);
+		__dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
+	}
+
+	/* check to see if the node is already considered dead */
+	if (!test_bit(idx, dlm->live_nodes_map)) {
+		mlog(0, "for domain %s, node %d is already dead. "
+		     "another node likely did recovery already.\n",
+		     dlm->name, idx);
+		return;
+	}
+
+	/* check to see if we do not care about this node */
+	if (!test_bit(idx, dlm->domain_map)) {
+		/* This also catches the case that we get a node down
+		 * but haven't joined the domain yet. */
+		mlog(0, "node %u already removed from domain!\n", idx);
+		return;
+	}
+
+	clear_bit(idx, dlm->live_nodes_map);
+
+	/* make sure local cleanup occurs before the heartbeat events */
+	if (!test_bit(idx, dlm->recovery_map))
+		dlm_do_local_recovery_cleanup(dlm, idx);
+
+	/* notify anything attached to the heartbeat events */
+	dlm_hb_event_notify_attached(dlm, idx, 0);
+
+	mlog(0, "node %u being removed from domain map!\n", idx);
+	clear_bit(idx, dlm->domain_map);
+	clear_bit(idx, dlm->exit_domain_map);
+	/* wake up migration waiters if a node goes down.
+	 * perhaps later we can genericize this for other waiters. */
+	wake_up(&dlm->migration_wq);
+
+	set_bit(idx, dlm->recovery_map);
+}
+
+void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
+{
+	struct dlm_ctxt *dlm = data;
+
+	if (!dlm_grab(dlm))
+		return;
+
+	/*
+	 * This will notify any dlm users that a node in our domain
+	 * went away without notifying us first.
+	 */
+	if (test_bit(idx, dlm->domain_map))
+		dlm_fire_domain_eviction_callbacks(dlm, idx);
+
+	spin_lock(&dlm->spinlock);
+	__dlm_hb_node_down(dlm, idx);
+	spin_unlock(&dlm->spinlock);
+
+	dlm_put(dlm);
+}
+
+void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
+{
+	struct dlm_ctxt *dlm = data;
+
+	if (!dlm_grab(dlm))
+		return;
+
+	spin_lock(&dlm->spinlock);
+	set_bit(idx, dlm->live_nodes_map);
+	/* do NOT notify mle attached to the heartbeat events.
+	 * new nodes are not interesting in mastery until joined. */
+	spin_unlock(&dlm->spinlock);
+
+	dlm_put(dlm);
+}
+
+static void dlm_reco_ast(void *astdata)
+{
+	struct dlm_ctxt *dlm = astdata;
+	mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
+	     dlm->node_num, dlm->name);
+}
+static void dlm_reco_bast(void *astdata, int blocked_type)
+{
+	struct dlm_ctxt *dlm = astdata;
+	mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
+	     dlm->node_num, dlm->name);
+}
+static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
+{
+	mlog(0, "unlockast for recovery lock fired!\n");
+}
+
+/*
+ * dlm_pick_recovery_master will continually attempt to use
+ * dlmlock() on the special "$RECOVERY" lockres with the
+ * LKM_NOQUEUE flag to get an EX.  every thread that enters
+ * this function on each node racing to become the recovery
+ * master will not stop attempting this until either:
+ * a) this node gets the EX (and becomes the recovery master),
+ * or b) dlm->reco.new_master gets set to some nodenum
+ * != O2NM_INVALID_NODE_NUM (another node will do the reco).
+ * so each time a recovery master is needed, the entire cluster
+ * will sync at this point.  if the new master dies, that will
+ * be detected in dlm_do_recovery */
+static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
+{
+	enum dlm_status ret;
+	struct dlm_lockstatus lksb;
+	int status = -EINVAL;
+
+	mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
+	     dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
+again:
+	memset(&lksb, 0, sizeof(lksb));
+
+	ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
+		      DLM_RECOVERY_LOCK_NAME, DLM_RECOVERY_LOCK_NAME_LEN,
+		      dlm_reco_ast, dlm, dlm_reco_bast);
+
+	mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
+	     dlm->name, ret, lksb.status);
+
+	if (ret == DLM_NORMAL) {
+		mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
+		     dlm->name, dlm->node_num);
+
+		/* got the EX lock.  check to see if another node
+		 * just became the reco master */
+		if (dlm_reco_master_ready(dlm)) {
+			mlog(0, "%s: got reco EX lock, but %u will "
+			     "do the recovery\n", dlm->name,
+			     dlm->reco.new_master);
+			status = -EEXIST;
+		} else {
+			status = 0;
+
+			/* see if recovery was already finished elsewhere */
+			spin_lock(&dlm->spinlock);
+			if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
+				status = -EINVAL;
+				mlog(0, "%s: got reco EX lock, but "
+				     "node got recovered already\n", dlm->name);
+				if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
+					mlog(ML_ERROR, "%s: new master is %u "
+					     "but no dead node!\n",
+					     dlm->name, dlm->reco.new_master);
+					BUG();
+				}
+			}
+			spin_unlock(&dlm->spinlock);
+		}
+
+		/* if this node has actually become the recovery master,
+		 * set the master and send the messages to begin recovery */
+		if (!status) {
+			mlog(0, "%s: dead=%u, this=%u, sending "
+			     "begin_reco now\n", dlm->name,
+			     dlm->reco.dead_node, dlm->node_num);
+			status = dlm_send_begin_reco_message(dlm,
+				      dlm->reco.dead_node);
+			/* this always succeeds */
+			BUG_ON(status);
+
+			/* set the new_master to this node */
+			spin_lock(&dlm->spinlock);
+			dlm_set_reco_master(dlm, dlm->node_num);
+			spin_unlock(&dlm->spinlock);
+		}
+
+		/* recovery lock is a special case.  ast will not get fired,
+		 * so just go ahead and unlock it. */
+		ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
+		if (ret == DLM_DENIED) {
+			mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
+			ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
+		}
+		if (ret != DLM_NORMAL) {
+			/* this would really suck. this could only happen
+			 * if there was a network error during the unlock
+			 * because of node death.  this means the unlock
+			 * is actually "done" and the lock structure is
+			 * even freed.  we can continue, but only
+			 * because this specific lock name is special. */
+			mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
+		}
+	} else if (ret == DLM_NOTQUEUED) {
+		mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
+		     dlm->name, dlm->node_num);
+		/* another node is master. wait on
+		 * reco.new_master != O2NM_INVALID_NODE_NUM
+		 * for at most one second */
+		wait_event_timeout(dlm->dlm_reco_thread_wq,
+					 dlm_reco_master_ready(dlm),
+					 msecs_to_jiffies(1000));
+		if (!dlm_reco_master_ready(dlm)) {
+			mlog(0, "%s: reco master taking awhile\n",
+			     dlm->name);
+			goto again;
+		}
+		/* another node has informed this one that it is reco master */
+		mlog(0, "%s: reco master %u is ready to recover %u\n",
+		     dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
+		status = -EEXIST;
+	} else if (ret == DLM_RECOVERING) {
+		mlog(0, "dlm=%s dlmlock says master node died (this=%u)\n",
+		     dlm->name, dlm->node_num);
+		goto again;
+	} else {
+		struct dlm_lock_resource *res;
+
+		/* dlmlock returned something other than NOTQUEUED or NORMAL */
+		mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
+		     "lksb.status=%s\n", dlm->name, dlm_errname(ret),
+		     dlm_errname(lksb.status));
+		res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
+					 DLM_RECOVERY_LOCK_NAME_LEN);
+		if (res) {
+			dlm_print_one_lock_resource(res);
+			dlm_lockres_put(res);
+		} else {
+			mlog(ML_ERROR, "recovery lock not found\n");
+		}
+		BUG();
+	}
+
+	return status;
+}
+
+static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
+{
+	struct dlm_begin_reco br;
+	int ret = 0;
+	struct dlm_node_iter iter;
+	int nodenum;
+	int status;
+
+	mlog(0, "%s: dead node is %u\n", dlm->name, dead_node);
+
+	spin_lock(&dlm->spinlock);
+	dlm_node_iter_init(dlm->domain_map, &iter);
+	spin_unlock(&dlm->spinlock);
+
+	clear_bit(dead_node, iter.node_map);
+
+	memset(&br, 0, sizeof(br));
+	br.node_idx = dlm->node_num;
+	br.dead_node = dead_node;
+
+	while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
+		ret = 0;
+		if (nodenum == dead_node) {
+			mlog(0, "not sending begin reco to dead node "
+				  "%u\n", dead_node);
+			continue;
+		}
+		if (nodenum == dlm->node_num) {
+			mlog(0, "not sending begin reco to self\n");
+			continue;
+		}
+retry:
+		mlog(0, "attempting to send begin reco msg to %d\n",
+			  nodenum);
+		ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
+					 &br, sizeof(br), nodenum, &status);
+		/* negative status is handled ok by caller here */
+		if (ret >= 0)
+			ret = status;
+		if (dlm_is_host_down(ret)) {
+			/* node is down.  not involved in recovery
+			 * so just keep going */
+			mlog(ML_NOTICE, "%s: node %u was down when sending "
+			     "begin reco msg (%d)\n", dlm->name, nodenum, ret);
+			ret = 0;
+		}
+
+		/*
+		 * Prior to commit aad1b15310b9bcd59fa81ab8f2b1513b59553ea8,
+		 * dlm_begin_reco_handler() returned EAGAIN and not -EAGAIN.
+		 * We are handling both for compatibility reasons.
+		 */
+		if (ret == -EAGAIN || ret == EAGAIN) {
+			mlog(0, "%s: trying to start recovery of node "
+			     "%u, but node %u is waiting for last recovery "
+			     "to complete, backoff for a bit\n", dlm->name,
+			     dead_node, nodenum);
+			msleep(100);
+			goto retry;
+		}
+		if (ret < 0) {
+			struct dlm_lock_resource *res;
+
+			/* this is now a serious problem, possibly ENOMEM
+			 * in the network stack.  must retry */
+			mlog_errno(ret);
+			mlog(ML_ERROR, "begin reco of dlm %s to node %u "
+			     "returned %d\n", dlm->name, nodenum, ret);
+			res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
+						 DLM_RECOVERY_LOCK_NAME_LEN);
+			if (res) {
+				dlm_print_one_lock_resource(res);
+				dlm_lockres_put(res);
+			} else {
+				mlog(ML_ERROR, "recovery lock not found\n");
+			}
+			/* sleep for a bit in hopes that we can avoid
+			 * another ENOMEM */
+			msleep(100);
+			goto retry;
+		}
+	}
+
+	return ret;
+}
+
+int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
+			   void **ret_data)
+{
+	struct dlm_ctxt *dlm = data;
+	struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;
+
+	/* ok to return 0, domain has gone away */
+	if (!dlm_grab(dlm))
+		return 0;
+
+	spin_lock(&dlm->spinlock);
+	if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
+		mlog(0, "%s: node %u wants to recover node %u (%u:%u) "
+		     "but this node is in finalize state, waiting on finalize2\n",
+		     dlm->name, br->node_idx, br->dead_node,
+		     dlm->reco.dead_node, dlm->reco.new_master);
+		spin_unlock(&dlm->spinlock);
+		dlm_put(dlm);
+		return -EAGAIN;
+	}
+	spin_unlock(&dlm->spinlock);
+
+	mlog(0, "%s: node %u wants to recover node %u (%u:%u)\n",
+	     dlm->name, br->node_idx, br->dead_node,
+	     dlm->reco.dead_node, dlm->reco.new_master);
+
+	dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);
+
+	spin_lock(&dlm->spinlock);
+	if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
+		if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
+			mlog(0, "%s: new_master %u died, changing "
+			     "to %u\n", dlm->name, dlm->reco.new_master,
+			     br->node_idx);
+		} else {
+			mlog(0, "%s: new_master %u NOT DEAD, changing "
+			     "to %u\n", dlm->name, dlm->reco.new_master,
+			     br->node_idx);
+			/* may not have seen the new master as dead yet */
+		}
+	}
+	if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
+		mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
+		     "node %u changing it to %u\n", dlm->name,
+		     dlm->reco.dead_node, br->node_idx, br->dead_node);
+	}
+	dlm_set_reco_master(dlm, br->node_idx);
+	dlm_set_reco_dead_node(dlm, br->dead_node);
+	if (!test_bit(br->dead_node, dlm->recovery_map)) {
+		mlog(0, "recovery master %u sees %u as dead, but this "
+		     "node has not yet.  marking %u as dead\n",
+		     br->node_idx, br->dead_node, br->dead_node);
+		if (!test_bit(br->dead_node, dlm->domain_map) ||
+		    !test_bit(br->dead_node, dlm->live_nodes_map))
+			mlog(0, "%u not in domain/live_nodes map "
+			     "so setting it in reco map manually\n",
+			     br->dead_node);
+		/* force the recovery cleanup in __dlm_hb_node_down
+		 * both of these will be cleared in a moment */
+		set_bit(br->dead_node, dlm->domain_map);
+		set_bit(br->dead_node, dlm->live_nodes_map);
+		__dlm_hb_node_down(dlm, br->dead_node);
+	}
+	spin_unlock(&dlm->spinlock);
+
+	dlm_kick_recovery_thread(dlm);
+
+	mlog(0, "%s: recovery started by node %u, for %u (%u:%u)\n",
+	     dlm->name, br->node_idx, br->dead_node,
+	     dlm->reco.dead_node, dlm->reco.new_master);
+
+	dlm_put(dlm);
+	return 0;
+}
+
+#define DLM_FINALIZE_STAGE2  0x01
+static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
+{
+	int ret = 0;
+	struct dlm_finalize_reco fr;
+	struct dlm_node_iter iter;
+	int nodenum;
+	int status;
+	int stage = 1;
+
+	mlog(0, "finishing recovery for node %s:%u, "
+	     "stage %d\n", dlm->name, dlm->reco.dead_node, stage);
+
+	spin_lock(&dlm->spinlock);
+	dlm_node_iter_init(dlm->domain_map, &iter);
+	spin_unlock(&dlm->spinlock);
+
+stage2:
+	memset(&fr, 0, sizeof(fr));
+	fr.node_idx = dlm->node_num;
+	fr.dead_node = dlm->reco.dead_node;
+	if (stage == 2)
+		fr.flags |= DLM_FINALIZE_STAGE2;
+
+	while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
+		if (nodenum == dlm->node_num)
+			continue;
+		ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
+					 &fr, sizeof(fr), nodenum, &status);
+		if (ret >= 0)
+			ret = status;
+		if (ret < 0) {
+			mlog(ML_ERROR, "Error %d when sending message %u (key "
+			     "0x%x) to node %u\n", ret, DLM_FINALIZE_RECO_MSG,
+			     dlm->key, nodenum);
+			if (dlm_is_host_down(ret)) {
+				/* this has no effect on this recovery
+				 * session, so set the status to zero to
+				 * finish out the last recovery */
+				mlog(ML_ERROR, "node %u went down after this "
+				     "node finished recovery.\n", nodenum);
+				ret = 0;
+				continue;
+			}
+			break;
+		}
+	}
+	if (stage == 1) {
+		/* reset the node_iter back to the top and send finalize2 */
+		iter.curnode = -1;
+		stage = 2;
+		goto stage2;
+	}
+
+	return ret;
+}
+
+int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
+			      void **ret_data)
+{
+	struct dlm_ctxt *dlm = data;
+	struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
+	int stage = 1;
+
+	/* ok to return 0, domain has gone away */
+	if (!dlm_grab(dlm))
+		return 0;
+
+	if (fr->flags & DLM_FINALIZE_STAGE2)
+		stage = 2;
+
+	mlog(0, "%s: node %u finalizing recovery stage%d of "
+	     "node %u (%u:%u)\n", dlm->name, fr->node_idx, stage,
+	     fr->dead_node, dlm->reco.dead_node, dlm->reco.new_master);
+
+	spin_lock(&dlm->spinlock);
+
+	if (dlm->reco.new_master != fr->node_idx) {
+		mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
+		     "%u is supposed to be the new master, dead=%u\n",
+		     fr->node_idx, dlm->reco.new_master, fr->dead_node);
+		BUG();
+	}
+	if (dlm->reco.dead_node != fr->dead_node) {
+		mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
+		     "node %u, but node %u is supposed to be dead\n",
+		     fr->node_idx, fr->dead_node, dlm->reco.dead_node);
+		BUG();
+	}
+
+	switch (stage) {
+		case 1:
+			dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
+			if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
+				mlog(ML_ERROR, "%s: received finalize1 from "
+				     "new master %u for dead node %u, but "
+				     "this node has already received it!\n",
+				     dlm->name, fr->node_idx, fr->dead_node);
+				dlm_print_reco_node_status(dlm);
+				BUG();
+			}
+			dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
+			spin_unlock(&dlm->spinlock);
+			break;
+		case 2:
+			if (!(dlm->reco.state & DLM_RECO_STATE_FINALIZE)) {
+				mlog(ML_ERROR, "%s: received finalize2 from "
+				     "new master %u for dead node %u, but "
+				     "this node did not have finalize1!\n",
+				     dlm->name, fr->node_idx, fr->dead_node);
+				dlm_print_reco_node_status(dlm);
+				BUG();
+			}
+			dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
+			__dlm_reset_recovery(dlm);
+			spin_unlock(&dlm->spinlock);
+			dlm_kick_recovery_thread(dlm);
+			break;
+	}
+
+	mlog(0, "%s: recovery done, reco master was %u, dead now %u, master now %u\n",
+	     dlm->name, fr->node_idx, dlm->reco.dead_node, dlm->reco.new_master);
+
+	dlm_put(dlm);
+	return 0;
+}