dlm: add recovery callbacks

These new callbacks notify the dlm user about lock recovery.
GFS2, and possibly others, need to be aware of when the dlm
will be doing lock recovery for a failed lockspace member.

In the past, this coordination has been done between dlm and
file system daemons in userspace, which then direct their
kernel counterparts.  These callbacks allow the same
coordination directly, and more simply.

Signed-off-by: David Teigland <teigland@redhat.com>

1 files changed, 125 insertions, 72 deletions

diff --git a/fs/dlm/member.c b/fs/dlm/member.c
index eebc52a..862640a 100644
--- a/fs/dlm/member.c
+++ b/fs/dlm/member.c
@@ -1,7 +1,7 @@
 /******************************************************************************
 *******************************************************************************
 **
-**  Copyright (C) 2005-2009 Red Hat, Inc.  All rights reserved.
+**  Copyright (C) 2005-2011 Red Hat, Inc.  All rights reserved.
 **
 **  This copyrighted material is made available to anyone wishing to use,
 **  modify, copy, or redistribute it subject to the terms and conditions
@@ -27,7 +27,7 @@ int dlm_slots_version(struct dlm_header *h)
 }
 
 void dlm_slot_save(struct dlm_ls *ls, struct dlm_rcom *rc,
-		  struct dlm_member *memb)
+		   struct dlm_member *memb)
 {
 	struct rcom_config *rf = (struct rcom_config *)rc->rc_buf;
 
@@ -317,59 +317,51 @@ static void add_ordered_member(struct dlm_ls *ls, struct dlm_member *new)
 	}
 }
 
-static int dlm_add_member(struct dlm_ls *ls, int nodeid)
+static int dlm_add_member(struct dlm_ls *ls, struct dlm_config_node *node)
 {
 	struct dlm_member *memb;
-	int w, error;
+	int error;
 
 	memb = kzalloc(sizeof(struct dlm_member), GFP_NOFS);
 	if (!memb)
 		return -ENOMEM;
 
-	w = dlm_node_weight(ls->ls_name, nodeid);
-	if (w < 0) {
-		kfree(memb);
-		return w;
-	}
-
-	error = dlm_lowcomms_connect_node(nodeid);
+	error = dlm_lowcomms_connect_node(node->nodeid);
 	if (error < 0) {
 		kfree(memb);
 		return error;
 	}
 
-	memb->nodeid = nodeid;
-	memb->weight = w;
+	memb->nodeid = node->nodeid;
+	memb->weight = node->weight;
+	memb->comm_seq = node->comm_seq;
 	add_ordered_member(ls, memb);
 	ls->ls_num_nodes++;
 	return 0;
 }
 
-static void dlm_remove_member(struct dlm_ls *ls, struct dlm_member *memb)
-{
-	list_move(&memb->list, &ls->ls_nodes_gone);
-	ls->ls_num_nodes--;
-}
-
-int dlm_is_member(struct dlm_ls *ls, int nodeid)
+static struct dlm_member *find_memb(struct list_head *head, int nodeid)
 {
 	struct dlm_member *memb;
 
-	list_for_each_entry(memb, &ls->ls_nodes, list) {
+	list_for_each_entry(memb, head, list) {
 		if (memb->nodeid == nodeid)
-			return 1;
+			return memb;
 	}
+	return NULL;
+}
+
+int dlm_is_member(struct dlm_ls *ls, int nodeid)
+{
+	if (find_memb(&ls->ls_nodes, nodeid))
+		return 1;
 	return 0;
 }
 
 int dlm_is_removed(struct dlm_ls *ls, int nodeid)
 {
-	struct dlm_member *memb;
-
-	list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
-		if (memb->nodeid == nodeid)
-			return 1;
-	}
+	if (find_memb(&ls->ls_nodes_gone, nodeid))
+		return 1;
 	return 0;
 }
 
@@ -460,10 +452,88 @@ static int ping_members(struct dlm_ls *ls)
 	return error;
 }
 
+static void dlm_lsop_recover_prep(struct dlm_ls *ls)
+{
+	if (!ls->ls_ops || !ls->ls_ops->recover_prep)
+		return;
+	ls->ls_ops->recover_prep(ls->ls_ops_arg);
+}
+
+static void dlm_lsop_recover_slot(struct dlm_ls *ls, struct dlm_member *memb)
+{
+	struct dlm_slot slot;
+	uint32_t seq;
+	int error;
+
+	if (!ls->ls_ops || !ls->ls_ops->recover_slot)
+		return;
+
+	/* if there is no comms connection with this node
+	   or the present comms connection is newer
+	   than the one when this member was added, then
+	   we consider the node to have failed (versus
+	   being removed due to dlm_release_lockspace) */
+
+	error = dlm_comm_seq(memb->nodeid, &seq);
+
+	if (!error && seq == memb->comm_seq)
+		return;
+
+	slot.nodeid = memb->nodeid;
+	slot.slot = memb->slot;
+
+	ls->ls_ops->recover_slot(ls->ls_ops_arg, &slot);
+}
+
+void dlm_lsop_recover_done(struct dlm_ls *ls)
+{
+	struct dlm_member *memb;
+	struct dlm_slot *slots;
+	int i, num;
+
+	if (!ls->ls_ops || !ls->ls_ops->recover_done)
+		return;
+
+	num = ls->ls_num_nodes;
+
+	slots = kzalloc(num * sizeof(struct dlm_slot), GFP_KERNEL);
+	if (!slots)
+		return;
+
+	i = 0;
+	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (i == num) {
+			log_error(ls, "dlm_lsop_recover_done bad num %d", num);
+			goto out;
+		}
+		slots[i].nodeid = memb->nodeid;
+		slots[i].slot = memb->slot;
+		i++;
+	}
+
+	ls->ls_ops->recover_done(ls->ls_ops_arg, slots, num,
+				 ls->ls_slot, ls->ls_generation);
+ out:
+	kfree(slots);
+}
+
+static struct dlm_config_node *find_config_node(struct dlm_recover *rv,
+						int nodeid)
+{
+	int i;
+
+	for (i = 0; i < rv->nodes_count; i++) {
+		if (rv->nodes[i].nodeid == nodeid)
+			return &rv->nodes[i];
+	}
+	return NULL;
+}
+
 int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv, int *neg_out)
 {
 	struct dlm_member *memb, *safe;
-	int i, error, found, pos = 0, neg = 0, low = -1;
+	struct dlm_config_node *node;
+	int i, error, neg = 0, low = -1;
 
 	/* previously removed members that we've not finished removing need to
 	   count as a negative change so the "neg" recovery steps will happen */
@@ -476,46 +546,32 @@ int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv, int *neg_out)
 	/* move departed members from ls_nodes to ls_nodes_gone */
 
 	list_for_each_entry_safe(memb, safe, &ls->ls_nodes, list) {
-		found = 0;
-		for (i = 0; i < rv->node_count; i++) {
-			if (memb->nodeid == rv->nodeids[i]) {
-				found = 1;
-				break;
-			}
-		}
+		node = find_config_node(rv, memb->nodeid);
+		if (node && !node->new)
+			continue;
 
-		if (!found) {
-			neg++;
-			dlm_remove_member(ls, memb);
+		if (!node) {
 			log_debug(ls, "remove member %d", memb->nodeid);
+		} else {
+			/* removed and re-added */
+			log_debug(ls, "remove member %d comm_seq %u %u",
+				  memb->nodeid, memb->comm_seq, node->comm_seq);
 		}
-	}
-
-	/* Add an entry to ls_nodes_gone for members that were removed and
-	   then added again, so that previous state for these nodes will be
-	   cleared during recovery. */
 
-	for (i = 0; i < rv->new_count; i++) {
-		if (!dlm_is_member(ls, rv->new[i]))
-			continue;
-		log_debug(ls, "new nodeid %d is a re-added member", rv->new[i]);
-
-		memb = kzalloc(sizeof(struct dlm_member), GFP_NOFS);
-		if (!memb)
-			return -ENOMEM;
-		memb->nodeid = rv->new[i];
-		list_add_tail(&memb->list, &ls->ls_nodes_gone);
 		neg++;
+		list_move(&memb->list, &ls->ls_nodes_gone);
+		ls->ls_num_nodes--;
+		dlm_lsop_recover_slot(ls, memb);
 	}
 
 	/* add new members to ls_nodes */
 
-	for (i = 0; i < rv->node_count; i++) {
-		if (dlm_is_member(ls, rv->nodeids[i]))
+	for (i = 0; i < rv->nodes_count; i++) {
+		node = &rv->nodes[i];
+		if (dlm_is_member(ls, node->nodeid))
 			continue;
-		dlm_add_member(ls, rv->nodeids[i]);
-		pos++;
-		log_debug(ls, "add member %d", rv->nodeids[i]);
+		dlm_add_member(ls, node);
+		log_debug(ls, "add member %d", node->nodeid);
 	}
 
 	list_for_each_entry(memb, &ls->ls_nodes, list) {
@@ -609,21 +665,22 @@ int dlm_ls_stop(struct dlm_ls *ls)
 
 	if (!ls->ls_recover_begin)
 		ls->ls_recover_begin = jiffies;
+
+	dlm_lsop_recover_prep(ls);
 	return 0;
 }
 
 int dlm_ls_start(struct dlm_ls *ls)
 {
 	struct dlm_recover *rv = NULL, *rv_old;
-	int *ids = NULL, *new = NULL;
-	int error, ids_count = 0, new_count = 0;
+	struct dlm_config_node *nodes;
+	int error, count;
 
 	rv = kzalloc(sizeof(struct dlm_recover), GFP_NOFS);
 	if (!rv)
 		return -ENOMEM;
 
-	error = dlm_nodeid_list(ls->ls_name, &ids, &ids_count,
-				&new, &new_count);
+	error = dlm_config_nodes(ls->ls_name, &nodes, &count);
 	if (error < 0)
 		goto fail;
 
@@ -638,10 +695,8 @@ int dlm_ls_start(struct dlm_ls *ls)
 		goto fail;
 	}
 
-	rv->nodeids = ids;
-	rv->node_count = ids_count;
-	rv->new = new;
-	rv->new_count = new_count;
+	rv->nodes = nodes;
+	rv->nodes_count = count;
 	rv->seq = ++ls->ls_recover_seq;
 	rv_old = ls->ls_recover_args;
 	ls->ls_recover_args = rv;
@@ -649,9 +704,8 @@ int dlm_ls_start(struct dlm_ls *ls)
 
 	if (rv_old) {
 		log_error(ls, "unused recovery %llx %d",
-			  (unsigned long long)rv_old->seq, rv_old->node_count);
-		kfree(rv_old->nodeids);
-		kfree(rv_old->new);
+			  (unsigned long long)rv_old->seq, rv_old->nodes_count);
+		kfree(rv_old->nodes);
 		kfree(rv_old);
 	}
 
@@ -660,8 +714,7 @@ int dlm_ls_start(struct dlm_ls *ls)
 
  fail:
 	kfree(rv);
-	kfree(ids);
-	kfree(new);
+	kfree(nodes);
 	return error;
 }