dlm: use rsbtbl as resource directory

Remove the dir hash table (dirtbl), and use
the rsb hash table (rsbtbl) as the resource
directory. It has always been an unnecessary
duplication of information.

This improves efficiency by using a single rsbtbl
lookup in many cases where both rsbtbl and dirtbl
lookups were needed previously.

This eliminates the need to handle cases of rsbtbl
and dirtbl being out of sync.

In many cases there will be memory savings because
the dir hash table no longer exists.

Signed-off-by: David Teigland <[e-mail]>

fs/dlm/config.c

···
 	unsigned int cl_tcp_port;
 	unsigned int cl_buffer_size;
 	unsigned int cl_rsbtbl_size;
-	unsigned int cl_dirtbl_size;
 	unsigned int cl_recover_timer;
 	unsigned int cl_toss_secs;
 	unsigned int cl_scan_secs;
···
 	CLUSTER_ATTR_TCP_PORT = 0,
 	CLUSTER_ATTR_BUFFER_SIZE,
 	CLUSTER_ATTR_RSBTBL_SIZE,
-	CLUSTER_ATTR_DIRTBL_SIZE,
 	CLUSTER_ATTR_RECOVER_TIMER,
 	CLUSTER_ATTR_TOSS_SECS,
 	CLUSTER_ATTR_SCAN_SECS,
···
 CLUSTER_ATTR(tcp_port, 1);
 CLUSTER_ATTR(buffer_size, 1);
 CLUSTER_ATTR(rsbtbl_size, 1);
-CLUSTER_ATTR(dirtbl_size, 1);
 CLUSTER_ATTR(recover_timer, 1);
 CLUSTER_ATTR(toss_secs, 1);
 CLUSTER_ATTR(scan_secs, 1);
···
 	[CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port.attr,
 	[CLUSTER_ATTR_BUFFER_SIZE] = &cluster_attr_buffer_size.attr,
 	[CLUSTER_ATTR_RSBTBL_SIZE] = &cluster_attr_rsbtbl_size.attr,
-	[CLUSTER_ATTR_DIRTBL_SIZE] = &cluster_attr_dirtbl_size.attr,
 	[CLUSTER_ATTR_RECOVER_TIMER] = &cluster_attr_recover_timer.attr,
 	[CLUSTER_ATTR_TOSS_SECS] = &cluster_attr_toss_secs.attr,
 	[CLUSTER_ATTR_SCAN_SECS] = &cluster_attr_scan_secs.attr,
···
 	cl->cl_tcp_port = dlm_config.ci_tcp_port;
 	cl->cl_buffer_size = dlm_config.ci_buffer_size;
 	cl->cl_rsbtbl_size = dlm_config.ci_rsbtbl_size;
-	cl->cl_dirtbl_size = dlm_config.ci_dirtbl_size;
 	cl->cl_recover_timer = dlm_config.ci_recover_timer;
 	cl->cl_toss_secs = dlm_config.ci_toss_secs;
 	cl->cl_scan_secs = dlm_config.ci_scan_secs;
···
 #define DEFAULT_TCP_PORT       21064
 #define DEFAULT_BUFFER_SIZE     4096
 #define DEFAULT_RSBTBL_SIZE     1024
-#define DEFAULT_DIRTBL_SIZE     1024
 #define DEFAULT_RECOVER_TIMER      5
 #define DEFAULT_TOSS_SECS         10
 #define DEFAULT_SCAN_SECS          5
···
 	.ci_tcp_port = DEFAULT_TCP_PORT,
 	.ci_buffer_size = DEFAULT_BUFFER_SIZE,
 	.ci_rsbtbl_size = DEFAULT_RSBTBL_SIZE,
-	.ci_dirtbl_size = DEFAULT_DIRTBL_SIZE,
 	.ci_recover_timer = DEFAULT_RECOVER_TIMER,
 	.ci_toss_secs = DEFAULT_TOSS_SECS,
 	.ci_scan_secs = DEFAULT_SCAN_SECS,

fs/dlm/config.h

···
 	int ci_tcp_port;
 	int ci_buffer_size;
 	int ci_rsbtbl_size;
-	int ci_dirtbl_size;
 	int ci_recover_timer;
 	int ci_toss_secs;
 	int ci_scan_secs;

fs/dlm/debug_fs.c

···
 	return rv;
 }
 
+static int print_format4(struct dlm_rsb *r, struct seq_file *s)
+{
+	int our_nodeid = dlm_our_nodeid();
+	int print_name = 1;
+	int i, rv;
+
+	lock_rsb(r);
+
+	rv = seq_printf(s, "rsb %p %d %d %d %d %lu %lx %d ",
+			r,
+			r->res_nodeid,
+			r->res_master_nodeid,
+			r->res_dir_nodeid,
+			our_nodeid,
+			r->res_toss_time,
+			r->res_flags,
+			r->res_length);
+	if (rv)
+		goto out;
+
+	for (i = 0; i < r->res_length; i++) {
+		if (!isascii(r->res_name[i]) || !isprint(r->res_name[i]))
+			print_name = 0;
+	}
+
+	seq_printf(s, "%s", print_name ? "str " : "hex");
+
+	for (i = 0; i < r->res_length; i++) {
+		if (print_name)
+			seq_printf(s, "%c", r->res_name[i]);
+		else
+			seq_printf(s, " %02x", (unsigned char)r->res_name[i]);
+	}
+	rv = seq_printf(s, "\n");
+ out:
+	unlock_rsb(r);
+	return rv;
+}
+
 struct rsbtbl_iter {
 	struct dlm_rsb *rsb;
 	unsigned bucket;
···
 		}
 		rv = print_format3(ri->rsb, seq);
 		break;
+	case 4:
+		if (ri->header) {
+			seq_printf(seq, "version 4 rsb 2\n");
+			ri->header = 0;
+		}
+		rv = print_format4(ri->rsb, seq);
+		break;
 	}
 
 	return rv;
···
 static const struct seq_operations format1_seq_ops;
 static const struct seq_operations format2_seq_ops;
 static const struct seq_operations format3_seq_ops;
+static const struct seq_operations format4_seq_ops;
 
 static void *table_seq_start(struct seq_file *seq, loff_t *pos)
 {
+	struct rb_root *tree;
 	struct rb_node *node;
 	struct dlm_ls *ls = seq->private;
 	struct rsbtbl_iter *ri;
 	struct dlm_rsb *r;
 	loff_t n = *pos;
 	unsigned bucket, entry;
+	int toss = (seq->op == &format4_seq_ops);
 
 	bucket = n >> 32;
 	entry = n & ((1LL << 32) - 1);
···
 		ri->format = 2;
 	if (seq->op == &format3_seq_ops)
 		ri->format = 3;
+	if (seq->op == &format4_seq_ops)
+		ri->format = 4;
+
+	tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
 
 	spin_lock(&ls->ls_rsbtbl[bucket].lock);
-	if (!RB_EMPTY_ROOT(&ls->ls_rsbtbl[bucket].keep)) {
-		for (node = rb_first(&ls->ls_rsbtbl[bucket].keep); node;
-		     node = rb_next(node)) {
+	if (!RB_EMPTY_ROOT(tree)) {
+		for (node = rb_first(tree); node; node = rb_next(node)) {
 			r = rb_entry(node, struct dlm_rsb, res_hashnode);
 			if (!entry--) {
 				dlm_hold_rsb(r);
···
 			kfree(ri);
 			return NULL;
 		}
+		tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
 
 		spin_lock(&ls->ls_rsbtbl[bucket].lock);
-		if (!RB_EMPTY_ROOT(&ls->ls_rsbtbl[bucket].keep)) {
-			node = rb_first(&ls->ls_rsbtbl[bucket].keep);
+		if (!RB_EMPTY_ROOT(tree)) {
+			node = rb_first(tree);
 			r = rb_entry(node, struct dlm_rsb, res_hashnode);
 			dlm_hold_rsb(r);
 			ri->rsb = r;
···
 {
 	struct dlm_ls *ls = seq->private;
 	struct rsbtbl_iter *ri = iter_ptr;
+	struct rb_root *tree;
 	struct rb_node *next;
 	struct dlm_rsb *r, *rp;
 	loff_t n = *pos;
 	unsigned bucket;
+	int toss = (seq->op == &format4_seq_ops);
 
 	bucket = n >> 32;
 
···
 			kfree(ri);
 			return NULL;
 		}
+		tree = toss ? &ls->ls_rsbtbl[bucket].toss : &ls->ls_rsbtbl[bucket].keep;
 
 		spin_lock(&ls->ls_rsbtbl[bucket].lock);
-		if (!RB_EMPTY_ROOT(&ls->ls_rsbtbl[bucket].keep)) {
-			next = rb_first(&ls->ls_rsbtbl[bucket].keep);
+		if (!RB_EMPTY_ROOT(tree)) {
+			next = rb_first(tree);
 			r = rb_entry(next, struct dlm_rsb, res_hashnode);
 			dlm_hold_rsb(r);
 			ri->rsb = r;
···
 	.show  = table_seq_show,
 };
 
+static const struct seq_operations format4_seq_ops = {
+	.start = table_seq_start,
+	.next  = table_seq_next,
+	.stop  = table_seq_stop,
+	.show  = table_seq_show,
+};
+
 static const struct file_operations format1_fops;
 static const struct file_operations format2_fops;
 static const struct file_operations format3_fops;
+static const struct file_operations format4_fops;
 
 static int table_open(struct inode *inode, struct file *file)
 {
···
 		ret = seq_open(file, &format2_seq_ops);
 	else if (file->f_op == &format3_fops)
 		ret = seq_open(file, &format3_seq_ops);
+	else if (file->f_op == &format4_fops)
+		ret = seq_open(file, &format4_seq_ops);
 
 	if (ret)
 		return ret;
···
 };
 
 static const struct file_operations format3_fops = {
+	.owner   = THIS_MODULE,
+	.open    = table_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release
+};
+
+static const struct file_operations format4_fops = {
 	.owner   = THIS_MODULE,
 	.open    = table_open,
 	.read    = seq_read,
···
 		debugfs_remove(ls->ls_debug_locks_dentry);
 	if (ls->ls_debug_all_dentry)
 		debugfs_remove(ls->ls_debug_all_dentry);
+	if (ls->ls_debug_toss_dentry)
+		debugfs_remove(ls->ls_debug_toss_dentry);
 }
 
 int dlm_create_debug_file(struct dlm_ls *ls)
···
 						      ls,
 						      &format3_fops);
 	if (!ls->ls_debug_all_dentry)
+		goto fail;
+
+	/* format 4 */
+
+	memset(name, 0, sizeof(name));
+	snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_toss", ls->ls_name);
+
+	ls->ls_debug_toss_dentry = debugfs_create_file(name,
+						       S_IFREG | S_IRUGO,
+						       dlm_root,
+						       ls,
+						       &format4_fops);
+	if (!ls->ls_debug_toss_dentry)
 		goto fail;
 
 	memset(name, 0, sizeof(name));

fs/dlm/dir.c

···
 #include "lock.h"
 #include "dir.h"
 
-
-static void put_free_de(struct dlm_ls *ls, struct dlm_direntry *de)
-{
-	spin_lock(&ls->ls_recover_list_lock);
-	list_add(&de->list, &ls->ls_recover_list);
-	spin_unlock(&ls->ls_recover_list_lock);
-}
-
-static struct dlm_direntry *get_free_de(struct dlm_ls *ls, int len)
-{
-	int found = 0;
-	struct dlm_direntry *de;
-
-	spin_lock(&ls->ls_recover_list_lock);
-	list_for_each_entry(de, &ls->ls_recover_list, list) {
-		if (de->length == len) {
-			list_del(&de->list);
-			de->master_nodeid = 0;
-			memset(de->name, 0, len);
-			found = 1;
-			break;
-		}
-	}
-	spin_unlock(&ls->ls_recover_list_lock);
-
-	if (!found)
-		de = kzalloc(sizeof(struct dlm_direntry) + len, GFP_NOFS);
-	return de;
-}
-
-void dlm_clear_free_entries(struct dlm_ls *ls)
-{
-	struct dlm_direntry *de;
-
-	spin_lock(&ls->ls_recover_list_lock);
-	while (!list_empty(&ls->ls_recover_list)) {
-		de = list_entry(ls->ls_recover_list.next, struct dlm_direntry,
-				list);
-		list_del(&de->list);
-		kfree(de);
-	}
-	spin_unlock(&ls->ls_recover_list_lock);
-}
-
 /*
  * We use the upper 16 bits of the hash value to select the directory node.
  * Low bits are used for distribution of rsb's among hash buckets on each node.
···
 
 int dlm_hash2nodeid(struct dlm_ls *ls, uint32_t hash)
 {
-	struct list_head *tmp;
-	struct dlm_member *memb = NULL;
-	uint32_t node, n = 0;
-	int nodeid;
+	uint32_t node;
 
-	if (ls->ls_num_nodes == 1) {
-		nodeid = dlm_our_nodeid();
-		goto out;
-	}
-
-	if (ls->ls_node_array) {
+	if (ls->ls_num_nodes == 1)
+		return dlm_our_nodeid();
+	else {
 		node = (hash >> 16) % ls->ls_total_weight;
-		nodeid = ls->ls_node_array[node];
-		goto out;
+		return ls->ls_node_array[node];
 	}
-
-	/* make_member_array() failed to kmalloc ls_node_array... */
-
-	node = (hash >> 16) % ls->ls_num_nodes;
-
-	list_for_each(tmp, &ls->ls_nodes) {
-		if (n++ != node)
-			continue;
-		memb = list_entry(tmp, struct dlm_member, list);
-		break;
-	}
-
-	DLM_ASSERT(memb , printk("num_nodes=%u n=%u node=%u\n",
-				 ls->ls_num_nodes, n, node););
-	nodeid = memb->nodeid;
- out:
-	return nodeid;
 }
 
 int dlm_dir_nodeid(struct dlm_rsb *r)
 {
-	return dlm_hash2nodeid(r->res_ls, r->res_hash);
+	return r->res_dir_nodeid;
 }
 
-static inline uint32_t dir_hash(struct dlm_ls *ls, char *name, int len)
+void dlm_recover_dir_nodeid(struct dlm_ls *ls)
 {
-	uint32_t val;
+	struct dlm_rsb *r;
 
-	val = jhash(name, len, 0);
-	val &= (ls->ls_dirtbl_size - 1);
-
-	return val;
-}
-
-static void add_entry_to_hash(struct dlm_ls *ls, struct dlm_direntry *de)
-{
-	uint32_t bucket;
-
-	bucket = dir_hash(ls, de->name, de->length);
-	list_add_tail(&de->list, &ls->ls_dirtbl[bucket].list);
-}
-
-static struct dlm_direntry *search_bucket(struct dlm_ls *ls, char *name,
-					  int namelen, uint32_t bucket)
-{
-	struct dlm_direntry *de;
-
-	list_for_each_entry(de, &ls->ls_dirtbl[bucket].list, list) {
-		if (de->length == namelen && !memcmp(name, de->name, namelen))
-			goto out;
+	down_read(&ls->ls_root_sem);
+	list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
+		r->res_dir_nodeid = dlm_hash2nodeid(ls, r->res_hash);
 	}
-	de = NULL;
- out:
-	return de;
-}
-
-void dlm_dir_remove_entry(struct dlm_ls *ls, int nodeid, char *name, int namelen)
-{
-	struct dlm_direntry *de;
-	uint32_t bucket;
-
-	bucket = dir_hash(ls, name, namelen);
-
-	spin_lock(&ls->ls_dirtbl[bucket].lock);
-
-	de = search_bucket(ls, name, namelen, bucket);
-
-	if (!de) {
-		log_error(ls, "remove fr %u none", nodeid);
-		goto out;
-	}
-
-	if (de->master_nodeid != nodeid) {
-		log_error(ls, "remove fr %u ID %u", nodeid, de->master_nodeid);
-		goto out;
-	}
-
-	list_del(&de->list);
-	kfree(de);
- out:
-	spin_unlock(&ls->ls_dirtbl[bucket].lock);
-}
-
-void dlm_dir_clear(struct dlm_ls *ls)
-{
-	struct list_head *head;
-	struct dlm_direntry *de;
-	int i;
-
-	DLM_ASSERT(list_empty(&ls->ls_recover_list), );
-
-	for (i = 0; i < ls->ls_dirtbl_size; i++) {
-		spin_lock(&ls->ls_dirtbl[i].lock);
-		head = &ls->ls_dirtbl[i].list;
-		while (!list_empty(head)) {
-			de = list_entry(head->next, struct dlm_direntry, list);
-			list_del(&de->list);
-			put_free_de(ls, de);
-		}
-		spin_unlock(&ls->ls_dirtbl[i].lock);
-	}
+	up_read(&ls->ls_root_sem);
 }
 
 int dlm_recover_directory(struct dlm_ls *ls)
 {
 	struct dlm_member *memb;
-	struct dlm_direntry *de;
 	char *b, *last_name = NULL;
-	int error = -ENOMEM, last_len, count = 0;
+	int error = -ENOMEM, last_len, nodeid, result;
 	uint16_t namelen;
+	unsigned int count = 0, count_match = 0, count_bad = 0, count_add = 0;
 
 	log_debug(ls, "dlm_recover_directory");
 
 	if (dlm_no_directory(ls))
 		goto out_status;
 
-	dlm_dir_clear(ls);
-
 	last_name = kmalloc(DLM_RESNAME_MAXLEN, GFP_NOFS);
 	if (!last_name)
 		goto out;
 
 	list_for_each_entry(memb, &ls->ls_nodes, list) {
+		if (memb->nodeid == dlm_our_nodeid())
+			continue;
+
 		memset(last_name, 0, DLM_RESNAME_MAXLEN);
 		last_len = 0;
 
···
 			if (error)
 				goto out_free;
 
-			schedule();
+			cond_resched();
 
 			/*
 			 * pick namelen/name pairs out of received buffer
···
 				if (namelen > DLM_RESNAME_MAXLEN)
 					goto out_free;
 
-				error = -ENOMEM;
-				de = get_free_de(ls, namelen);
-				if (!de)
+				error = dlm_master_lookup(ls, memb->nodeid,
+							  b, namelen,
+							  DLM_LU_RECOVER_DIR,
+							  &nodeid, &result);
+				if (error) {
+					log_error(ls, "recover_dir lookup %d",
+						  error);
 					goto out_free;
+				}
 
-				de->master_nodeid = memb->nodeid;
-				de->length = namelen;
+				/* The name was found in rsbtbl, but the
+				 * master nodeid is different from
+				 * memb->nodeid which says it is the master.
+				 * This should not happen. */
+
+				if (result == DLM_LU_MATCH &&
+				    nodeid != memb->nodeid) {
+					count_bad++;
+					log_error(ls, "recover_dir lookup %d "
+						  "nodeid %d memb %d bad %u",
+						  result, nodeid, memb->nodeid,
+						  count_bad);
+					print_hex_dump_bytes("dlm_recover_dir ",
+							     DUMP_PREFIX_NONE,
+							     b, namelen);
+				}
+
+				/* The name was found in rsbtbl, and the
+				 * master nodeid matches memb->nodeid. */
+
+				if (result == DLM_LU_MATCH &&
+				    nodeid == memb->nodeid) {
+					count_match++;
+				}
+
+				/* The name was not found in rsbtbl and was
+				 * added with memb->nodeid as the master. */
+
+				if (result == DLM_LU_ADD) {
+					count_add++;
+				}
+
 				last_len = namelen;
-				memcpy(de->name, b, namelen);
 				memcpy(last_name, b, namelen);
 				b += namelen;
 				left -= namelen;
-
-				add_entry_to_hash(ls, de);
 				count++;
 			}
 		}
-         done:
+	 done:
 		;
 	}
 
  out_status:
 	error = 0;
-	log_debug(ls, "dlm_recover_directory %d entries", count);
+	dlm_set_recover_status(ls, DLM_RS_DIR);
+
+	log_debug(ls, "dlm_recover_directory %u in %u new",
+		  count, count_add);
  out_free:
 	kfree(last_name);
  out:
-	dlm_clear_free_entries(ls);
 	return error;
-}
-
-static int get_entry(struct dlm_ls *ls, int nodeid, char *name,
-		     int namelen, int *r_nodeid)
-{
-	struct dlm_direntry *de, *tmp;
-	uint32_t bucket;
-
-	bucket = dir_hash(ls, name, namelen);
-
-	spin_lock(&ls->ls_dirtbl[bucket].lock);
-	de = search_bucket(ls, name, namelen, bucket);
-	if (de) {
-		*r_nodeid = de->master_nodeid;
-		spin_unlock(&ls->ls_dirtbl[bucket].lock);
-		if (*r_nodeid == nodeid)
-			return -EEXIST;
-		return 0;
-	}
-
-	spin_unlock(&ls->ls_dirtbl[bucket].lock);
-
-	if (namelen > DLM_RESNAME_MAXLEN)
-		return -EINVAL;
-
-	de = kzalloc(sizeof(struct dlm_direntry) + namelen, GFP_NOFS);
-	if (!de)
-		return -ENOMEM;
-
-	de->master_nodeid = nodeid;
-	de->length = namelen;
-	memcpy(de->name, name, namelen);
-
-	spin_lock(&ls->ls_dirtbl[bucket].lock);
-	tmp = search_bucket(ls, name, namelen, bucket);
-	if (tmp) {
-		kfree(de);
-		de = tmp;
-	} else {
-		list_add_tail(&de->list, &ls->ls_dirtbl[bucket].list);
-	}
-	*r_nodeid = de->master_nodeid;
-	spin_unlock(&ls->ls_dirtbl[bucket].lock);
-	return 0;
-}
-
-int dlm_dir_lookup(struct dlm_ls *ls, int nodeid, char *name, int namelen,
-		   int *r_nodeid)
-{
-	return get_entry(ls, nodeid, name, namelen, r_nodeid);
 }
 
 static struct dlm_rsb *find_rsb_root(struct dlm_ls *ls, char *name, int len)
···
 	bucket = hash & (ls->ls_rsbtbl_size - 1);
 
 	spin_lock(&ls->ls_rsbtbl[bucket].lock);
-	rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].keep, name, len, 0, &r);
+	rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].keep, name, len, &r);
 	if (rv)
 		rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].toss,
-					 name, len, 0, &r);
+					 name, len, &r);
 	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 
 	if (!rv)
···
 	list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
 		if (len == r->res_length && !memcmp(name, r->res_name, len)) {
 			up_read(&ls->ls_root_sem);
-			log_error(ls, "find_rsb_root revert to root_list %s",
+			log_debug(ls, "find_rsb_root revert to root_list %s",
 				  r->res_name);
 			return r;
 		}
···
 			be_namelen = cpu_to_be16(0);
 			memcpy(outbuf + offset, &be_namelen, sizeof(__be16));
 			offset += sizeof(__be16);
+			ls->ls_recover_dir_sent_msg++;
 			goto out;
 		}
 
···
 		offset += sizeof(__be16);
 		memcpy(outbuf + offset, r->res_name, r->res_length);
 		offset += r->res_length;
+		ls->ls_recover_dir_sent_res++;
 	}
 
 	/*
···
 		be_namelen = cpu_to_be16(0xFFFF);
 		memcpy(outbuf + offset, &be_namelen, sizeof(__be16));
 		offset += sizeof(__be16);
+		ls->ls_recover_dir_sent_msg++;
 	}
-
  out:
 	up_read(&ls->ls_root_sem);
 }

fs/dlm/dir.h

···
 #ifndef __DIR_DOT_H__
 #define __DIR_DOT_H__
 
-
 int dlm_dir_nodeid(struct dlm_rsb *rsb);
 int dlm_hash2nodeid(struct dlm_ls *ls, uint32_t hash);
-void dlm_dir_remove_entry(struct dlm_ls *ls, int nodeid, char *name, int len);
-void dlm_dir_clear(struct dlm_ls *ls);
-void dlm_clear_free_entries(struct dlm_ls *ls);
+void dlm_recover_dir_nodeid(struct dlm_ls *ls);
 int dlm_recover_directory(struct dlm_ls *ls);
-int dlm_dir_lookup(struct dlm_ls *ls, int nodeid, char *name, int namelen,
-	int *r_nodeid);
 void dlm_copy_master_names(struct dlm_ls *ls, char *inbuf, int inlen,
 	char *outbuf, int outlen, int nodeid);
 

fs/dlm/dlm_internal.h

···
 struct dlm_rsb;
 struct dlm_member;
 struct dlm_rsbtable;
-struct dlm_dirtable;
-struct dlm_direntry;
 struct dlm_recover;
 struct dlm_header;
 struct dlm_message;
···
   } \
 }
 
-
-struct dlm_direntry {
-	struct list_head	list;
-	uint32_t		master_nodeid;
-	uint16_t		length;
-	char			name[1];
-};
-
-struct dlm_dirtable {
-	struct list_head	list;
-	spinlock_t		lock;
-};
 
 struct dlm_rsbtable {
 	struct rb_root		keep;
···
 	};
 };
 
+/*
+ * res_master_nodeid is "normal": 0 is unset/invalid, non-zero is the real
+ * nodeid, even when nodeid is our_nodeid.
+ *
+ * res_nodeid is "odd": -1 is unset/invalid, zero means our_nodeid,
+ * greater than zero when another nodeid.
+ *
+ * (TODO: remove res_nodeid and only use res_master_nodeid)
+ */
 
 struct dlm_rsb {
 	struct dlm_ls		*res_ls;	/* the lockspace */
···
 	unsigned long		res_flags;
 	int			res_length;	/* length of rsb name */
 	int			res_nodeid;
+	int			res_master_nodeid;
+	int			res_dir_nodeid;
 	uint32_t                res_lvbseq;
 	uint32_t		res_hash;
 	uint32_t		res_bucket;	/* rsbtbl */
···
 	char			res_name[DLM_RESNAME_MAXLEN+1];
 };
 
+/* dlm_master_lookup() flags */
+
+#define DLM_LU_RECOVER_DIR	1
+#define DLM_LU_RECOVER_MASTER	2
+
+/* dlm_master_lookup() results */
+
+#define DLM_LU_MATCH		1
+#define DLM_LU_ADD		2
+
 /* find_rsb() flags */
 
-#define R_MASTER		1	/* only return rsb if it's a master */
-#define R_CREATE		2	/* create/add rsb if not found */
+#define R_REQUEST		0x00000001
+#define R_RECEIVE_REQUEST	0x00000002
+#define R_RECEIVE_RECOVER	0x00000004
 
 /* rsb_flags */
 
···
 	struct dlm_rsbtable	*ls_rsbtbl;
 	uint32_t		ls_rsbtbl_size;
 
-	struct dlm_dirtable	*ls_dirtbl;
-	uint32_t		ls_dirtbl_size;
-
 	struct mutex		ls_waiters_mutex;
 	struct list_head	ls_waiters;	/* lkbs needing a reply */
 
···
 	struct dentry		*ls_debug_waiters_dentry; /* debugfs */
 	struct dentry		*ls_debug_locks_dentry; /* debugfs */
 	struct dentry		*ls_debug_all_dentry; /* debugfs */
+	struct dentry		*ls_debug_toss_dentry; /* debugfs */
 
 	wait_queue_head_t	ls_uevent_wait;	/* user part of join/leave */
 	int			ls_uevent_result;
···
 	struct mutex		ls_requestqueue_mutex;
 	struct dlm_rcom		*ls_recover_buf;
 	int			ls_recover_nodeid; /* for debugging */
+	unsigned int		ls_recover_dir_sent_res; /* for log info */
+	unsigned int		ls_recover_dir_sent_msg; /* for log info */
 	unsigned int		ls_recover_locks_in; /* for log info */
 	uint64_t		ls_rcom_seq;
 	spinlock_t		ls_rcom_spin;

fs/dlm/lock.c

···
 static int receive_extralen(struct dlm_message *ms);
 static void do_purge(struct dlm_ls *ls, int nodeid, int pid);
 static void del_timeout(struct dlm_lkb *lkb);
+static void toss_rsb(struct kref *kref);
 
 /*
  * Lock compatibilty matrix - thanks Steve
···
 
 static void dlm_print_rsb(struct dlm_rsb *r)
 {
-	printk(KERN_ERR "rsb: nodeid %d flags %lx first %x rlc %d name %s\n",
-	       r->res_nodeid, r->res_flags, r->res_first_lkid,
-	       r->res_recover_locks_count, r->res_name);
+	printk(KERN_ERR "rsb: nodeid %d master %d dir %d flags %lx first %x "
+	       "rlc %d name %s\n",
+	       r->res_nodeid, r->res_master_nodeid, r->res_dir_nodeid,
+	       r->res_flags, r->res_first_lkid, r->res_recover_locks_count,
+	       r->res_name);
 }
 
 void dlm_dump_rsb(struct dlm_rsb *r)
···
  * Basic operations on rsb's and lkb's
  */
 
+/* This is only called to add a reference when the code already holds
+   a valid reference to the rsb, so there's no need for locking. */
+
+static inline void hold_rsb(struct dlm_rsb *r)
+{
+	kref_get(&r->res_ref);
+}
+
+void dlm_hold_rsb(struct dlm_rsb *r)
+{
+	hold_rsb(r);
+}
+
+/* When all references to the rsb are gone it's transferred to
+   the tossed list for later disposal. */
+
+static void put_rsb(struct dlm_rsb *r)
+{
+	struct dlm_ls *ls = r->res_ls;
+	uint32_t bucket = r->res_bucket;
+
+	spin_lock(&ls->ls_rsbtbl[bucket].lock);
+	kref_put(&r->res_ref, toss_rsb);
+	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+}
+
+void dlm_put_rsb(struct dlm_rsb *r)
+{
+	put_rsb(r);
+}
+
 static int pre_rsb_struct(struct dlm_ls *ls)
 {
 	struct dlm_rsb *r1, *r2;
···
 }
 
 int dlm_search_rsb_tree(struct rb_root *tree, char *name, int len,
-			unsigned int flags, struct dlm_rsb **r_ret)
+			struct dlm_rsb **r_ret)
 {
 	struct rb_node *node = tree->rb_node;
 	struct dlm_rsb *r;
-	int error = 0;
 	int rc;
 
 	while (node) {
···
 	return -EBADR;
 
  found:
-	if (r->res_nodeid && (flags & R_MASTER))
-		error = -ENOTBLK;
 	*r_ret = r;
-	return error;
+	return 0;
 }
 
 static int rsb_insert(struct dlm_rsb *rsb, struct rb_root *tree)
···
 	return 0;
 }
 
-static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b,
-		       unsigned int flags, struct dlm_rsb **r_ret)
-{
-	struct dlm_rsb *r;
-	int error;
-
-	error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, flags, &r);
-	if (!error) {
-		kref_get(&r->res_ref);
-		goto out;
-	}
-	if (error == -ENOTBLK)
-		goto out;
-
-	error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
-	if (error)
-		goto out;
-
-	rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
-	error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
-	if (error)
-		return error;
-
-	if (dlm_no_directory(ls))
-		goto out;
-
-	if (r->res_nodeid == -1) {
-		rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
-		r->res_first_lkid = 0;
-	} else if (r->res_nodeid > 0) {
-		rsb_set_flag(r, RSB_MASTER_UNCERTAIN);
-		r->res_first_lkid = 0;
-	} else {
-		DLM_ASSERT(r->res_nodeid == 0, dlm_print_rsb(r););
-		DLM_ASSERT(!rsb_flag(r, RSB_MASTER_UNCERTAIN),);
-	}
- out:
-	*r_ret = r;
-	return error;
-}
-
 /*
  * Find rsb in rsbtbl and potentially create/add one
  *
···
  * Searching for an rsb means looking through both the normal list and toss
  * list.  When found on the toss list the rsb is moved to the normal list with
  * ref count of 1; when found on normal list the ref count is incremented.
+ *
+ * rsb's on the keep list are being used locally and refcounted.
+ * rsb's on the toss list are not being used locally, and are not refcounted.
+ *
+ * The toss list rsb's were either
+ * - previously used locally but not any more (were on keep list, then
+ *   moved to toss list when last refcount dropped)
+ * - created and put on toss list as a directory record for a lookup
+ *   (we are the dir node for the res, but are not using the res right now,
+ *   but some other node is)
+ *
+ * The purpose of find_rsb() is to return a refcounted rsb for local use.
+ * So, if the given rsb is on the toss list, it is moved to the keep list
+ * before being returned.
+ *
+ * toss_rsb() happens when all local usage of the rsb is done, i.e. no
+ * more refcounts exist, so the rsb is moved from the keep list to the
+ * toss list.
+ *
+ * rsb's on both keep and toss lists are used for doing a name to master
+ * lookups.  rsb's that are in use locally (and being refcounted) are on
+ * the keep list, rsb's that are not in use locally (not refcounted) and
+ * only exist for name/master lookups are on the toss list.
+ *
+ * rsb's on the toss list who's dir_nodeid is not local can have stale
+ * name/master mappings.  So, remote requests on such rsb's can potentially
+ * return with an error, which means the mapping is stale and needs to
+ * be updated with a new lookup.  (The idea behind MASTER UNCERTAIN and
+ * first_lkid is to keep only a single outstanding request on an rsb
+ * while that rsb has a potentially stale master.)
  */
 
-static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
-		    unsigned int flags, struct dlm_rsb **r_ret)
+static int find_rsb_dir(struct dlm_ls *ls, char *name, int len,
+			uint32_t hash, uint32_t b,
+			int dir_nodeid, int from_nodeid,
+			unsigned int flags, struct dlm_rsb **r_ret)
 {
 	struct dlm_rsb *r = NULL;
-	uint32_t hash, bucket;
+	int our_nodeid = dlm_our_nodeid();
+	int from_local = 0;
+	int from_other = 0;
+	int from_dir = 0;
+	int create = 0;
 	int error;
 
-	if (namelen > DLM_RESNAME_MAXLEN) {
-		error = -EINVAL;
-		goto out;
+	if (flags & R_RECEIVE_REQUEST) {
+		if (from_nodeid == dir_nodeid)
+			from_dir = 1;
+		else
+			from_other = 1;
+	} else if (flags & R_REQUEST) {
+		from_local = 1;
 	}
 
-	if (dlm_no_directory(ls))
-		flags |= R_CREATE;
+	/*
+	 * flags & R_RECEIVE_RECOVER is from dlm_recover_master_copy, so
+	 * from_nodeid has sent us a lock in dlm_recover_locks, believing
+	 * we're the new master.  Our local recovery may not have set
+	 * res_master_nodeid to our_nodeid yet, so allow either.  Don't
+	 * create the rsb; dlm_recover_process_copy() will handle EBADR
+	 * by resending.
+	 *
+	 * If someone sends us a request, we are the dir node, and we do
+	 * not find the rsb anywhere, then recreate it.  This happens if
+	 * someone sends us a request after we have removed/freed an rsb
+	 * from our toss list.  (They sent a request instead of lookup
+	 * because they are using an rsb from their toss list.)
+	 */
 
-	hash = jhash(name, namelen, 0);
-	bucket = hash & (ls->ls_rsbtbl_size - 1);
+	if (from_local || from_dir ||
+	    (from_other && (dir_nodeid == our_nodeid))) {
+		create = 1;
+	}
 
  retry:
-	if (flags & R_CREATE) {
+	if (create) {
 		error = pre_rsb_struct(ls);
 		if (error < 0)
 			goto out;
 	}
 
-	spin_lock(&ls->ls_rsbtbl[bucket].lock);
+	spin_lock(&ls->ls_rsbtbl[b].lock);
 
-	error = _search_rsb(ls, name, namelen, bucket, flags, &r);
-	if (!error)
+	error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
+	if (error)
+		goto do_toss;
+	
+	/*
+	 * rsb is active, so we can't check master_nodeid without lock_rsb.
+	 */
+
+	kref_get(&r->res_ref);
+	error = 0;
+	goto out_unlock;
+
+
+ do_toss:
+	error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
+	if (error)
+		goto do_new;
+
+	/*
+	 * rsb found inactive (master_nodeid may be out of date unless
+	 * we are the dir_nodeid or were the master)  No other thread
+	 * is using this rsb because it's on the toss list, so we can
+	 * look at or update res_master_nodeid without lock_rsb.
+	 */
+
+	if ((r->res_master_nodeid != our_nodeid) && from_other) {
+		/* our rsb was not master, and another node (not the dir node)
+		   has sent us a request */
+		log_debug(ls, "find_rsb toss from_other %d master %d dir %d %s",
+			  from_nodeid, r->res_master_nodeid, dir_nodeid,
+			  r->res_name);
+		error = -ENOTBLK;
+		goto out_unlock;
+	}
+
+	if ((r->res_master_nodeid != our_nodeid) && from_dir) {
+		/* don't think this should ever happen */
+		log_error(ls, "find_rsb toss from_dir %d master %d",
+			  from_nodeid, r->res_master_nodeid);
+		dlm_print_rsb(r);
+		/* fix it and go on */
+		r->res_master_nodeid = our_nodeid;
+		r->res_nodeid = 0;
+		rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
+		r->res_first_lkid = 0;
+	}
+
+	if (from_local && (r->res_master_nodeid != our_nodeid)) {
+		/* Because we have held no locks on this rsb,
+		   res_master_nodeid could have become stale. */
+		rsb_set_flag(r, RSB_MASTER_UNCERTAIN);
+		r->res_first_lkid = 0;
+	}
+
+	rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
+	error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
+	goto out_unlock;
+
+
+ do_new:
+	/*
+	 * rsb not found
+	 */
+
+	if (error == -EBADR && !create)
 		goto out_unlock;
 
-	if (error == -EBADR && !(flags & R_CREATE))
-		goto out_unlock;
-
-	/* the rsb was found but wasn't a master copy */
-	if (error == -ENOTBLK)
-		goto out_unlock;
-
-	error = get_rsb_struct(ls, name, namelen, &r);
+	error = get_rsb_struct(ls, name, len, &r);
 	if (error == -EAGAIN) {
-		spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+		spin_unlock(&ls->ls_rsbtbl[b].lock);
 		goto retry;
 	}
 	if (error)
 		goto out_unlock;
 
 	r->res_hash = hash;
-	r->res_bucket = bucket;
-	r->res_nodeid = -1;
+	r->res_bucket = b;
+	r->res_dir_nodeid = dir_nodeid;
 	kref_init(&r->res_ref);
 
-	/* With no directory, the master can be set immediately */
-	if (dlm_no_directory(ls)) {
-		int nodeid = dlm_dir_nodeid(r);
-		if (nodeid == dlm_our_nodeid())
-			nodeid = 0;
-		r->res_nodeid = nodeid;
+	if (from_dir) {
+		/* want to see how often this happens */
+		log_debug(ls, "find_rsb new from_dir %d recreate %s",
+			  from_nodeid, r->res_name);
+		r->res_master_nodeid = our_nodeid;
+		r->res_nodeid = 0;
+		goto out_add;
 	}
-	error = rsb_insert(r, &ls->ls_rsbtbl[bucket].keep);
+
+	if (from_other && (dir_nodeid != our_nodeid)) {
+		/* should never happen */
+		log_error(ls, "find_rsb new from_other %d dir %d our %d %s",
+			  from_nodeid, dir_nodeid, our_nodeid, r->res_name);
+		dlm_free_rsb(r);
+		error = -ENOTBLK;
+		goto out_unlock;
+	}
+
+	if (from_other) {
+		log_debug(ls, "find_rsb new from_other %d dir %d %s",
+			  from_nodeid, dir_nodeid, r->res_name);
+	}
+
+	if (dir_nodeid == our_nodeid) {
+		/* When we are the dir nodeid, we can set the master
+		   node immediately */
+		r->res_master_nodeid = our_nodeid;
+		r->res_nodeid = 0;
+	} else {
+		/* set_master will send_lookup to dir_nodeid */
+		r->res_master_nodeid = 0;
+		r->res_nodeid = -1;
+	}
+
+ out_add:
+	error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
  out_unlock:
-	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+	spin_unlock(&ls->ls_rsbtbl[b].lock);
  out:
 	*r_ret = r;
+	return error;
+}
+
+/* During recovery, other nodes can send us new MSTCPY locks (from
+   dlm_recover_locks) before we've made ourself master (in
+   dlm_recover_masters). */
+
+static int find_rsb_nodir(struct dlm_ls *ls, char *name, int len,
+			  uint32_t hash, uint32_t b,
+			  int dir_nodeid, int from_nodeid,
+			  unsigned int flags, struct dlm_rsb **r_ret)
+{
+	struct dlm_rsb *r = NULL;
+	int our_nodeid = dlm_our_nodeid();
+	int recover = (flags & R_RECEIVE_RECOVER);
+	int error;
+
+ retry:
+	error = pre_rsb_struct(ls);
+	if (error < 0)
+		goto out;
+
+	spin_lock(&ls->ls_rsbtbl[b].lock);
+
+	error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
+	if (error)
+		goto do_toss;
+
+	/*
+	 * rsb is active, so we can't check master_nodeid without lock_rsb.
+	 */
+
+	kref_get(&r->res_ref);
+	goto out_unlock;
+
+
+ do_toss:
+	error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
+	if (error)
+		goto do_new;
+
+	/*
+	 * rsb found inactive. No other thread is using this rsb because
+	 * it's on the toss list, so we can look at or update
+	 * res_master_nodeid without lock_rsb.
+	 */
+
+	if (!recover && (r->res_master_nodeid != our_nodeid) && from_nodeid) {
+		/* our rsb is not master, and another node has sent us a
+		   request; this should never happen */
+		log_error(ls, "find_rsb toss from_nodeid %d master %d dir %d",
+			  from_nodeid, r->res_master_nodeid, dir_nodeid);
+		dlm_print_rsb(r);
+		error = -ENOTBLK;
+		goto out_unlock;
+	}
+
+	if (!recover && (r->res_master_nodeid != our_nodeid) &&
+	    (dir_nodeid == our_nodeid)) {
+		/* our rsb is not master, and we are dir; may as well fix it;
+		   this should never happen */
+		log_error(ls, "find_rsb toss our %d master %d dir %d",
+			  our_nodeid, r->res_master_nodeid, dir_nodeid);
+		dlm_print_rsb(r);
+		r->res_master_nodeid = our_nodeid;
+		r->res_nodeid = 0;
+	}
+
+	rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
+	error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
+	goto out_unlock;
+
+
+ do_new:
+	/*
+	 * rsb not found
+	 */
+
+	error = get_rsb_struct(ls, name, len, &r);
+	if (error == -EAGAIN) {
+		spin_unlock(&ls->ls_rsbtbl[b].lock);
+		goto retry;
+	}
+	if (error)
+		goto out_unlock;
+
+	r->res_hash = hash;
+	r->res_bucket = b;
+	r->res_dir_nodeid = dir_nodeid;
+	r->res_master_nodeid = dir_nodeid;
+	r->res_nodeid = (dir_nodeid == our_nodeid) ? 0 : dir_nodeid;
+	kref_init(&r->res_ref);
+
+	error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
+ out_unlock:
+	spin_unlock(&ls->ls_rsbtbl[b].lock);
+ out:
+	*r_ret = r;
+	return error;
+}
+
+static int find_rsb(struct dlm_ls *ls, char *name, int len, int from_nodeid,
+		    unsigned int flags, struct dlm_rsb **r_ret)
+{
+	uint32_t hash, b;
+	int dir_nodeid;
+
+	if (len > DLM_RESNAME_MAXLEN)
+		return -EINVAL;
+
+	hash = jhash(name, len, 0);
+	b = hash & (ls->ls_rsbtbl_size - 1);
+
+	dir_nodeid = dlm_hash2nodeid(ls, hash);
+
+	if (dlm_no_directory(ls))
+		return find_rsb_nodir(ls, name, len, hash, b, dir_nodeid,
+				      from_nodeid, flags, r_ret);
+	else
+		return find_rsb_dir(ls, name, len, hash, b, dir_nodeid,
+				      from_nodeid, flags, r_ret);
+}
+
+/* we have received a request and found that res_master_nodeid != our_nodeid,
+   so we need to return an error or make ourself the master */
+
+static int validate_master_nodeid(struct dlm_ls *ls, struct dlm_rsb *r,
+				  int from_nodeid)
+{
+	if (dlm_no_directory(ls)) {
+		log_error(ls, "find_rsb keep from_nodeid %d master %d dir %d",
+			  from_nodeid, r->res_master_nodeid,
+			  r->res_dir_nodeid);
+		dlm_print_rsb(r);
+		return -ENOTBLK;
+	}
+
+	if (from_nodeid != r->res_dir_nodeid) {
+		/* our rsb is not master, and another node (not the dir node)
+	   	   has sent us a request.  this is much more common when our
+	   	   master_nodeid is zero, so limit debug to non-zero.  */
+
+		if (r->res_master_nodeid) {
+			log_debug(ls, "validate master from_other %d master %d "
+				  "dir %d first %x %s", from_nodeid,
+				  r->res_master_nodeid, r->res_dir_nodeid,
+				  r->res_first_lkid, r->res_name);
+		}
+		return -ENOTBLK;
+	} else {
+		/* our rsb is not master, but the dir nodeid has sent us a
+	   	   request; this could happen with master 0 / res_nodeid -1 */
+
+		if (r->res_master_nodeid) {
+			log_error(ls, "validate master from_dir %d master %d "
+				  "first %x %s",
+				  from_nodeid, r->res_master_nodeid,
+				  r->res_first_lkid, r->res_name);
+		}
+
+		r->res_master_nodeid = dlm_our_nodeid();
+		r->res_nodeid = 0;
+		return 0;
+	}
+}
+
+/*
+ * We're the dir node for this res and another node wants to know the
+ * master nodeid.  During normal operation (non recovery) this is only
+ * called from receive_lookup(); master lookups when the local node is
+ * the dir node are done by find_rsb().
+ *
+ * normal operation, we are the dir node for a resource
+ * . _request_lock
+ * . set_master
+ * . send_lookup
+ * . receive_lookup
+ * . dlm_master_lookup flags 0
+ *
+ * recover directory, we are rebuilding dir for all resources
+ * . dlm_recover_directory
+ * . dlm_rcom_names
+ *   remote node sends back the rsb names it is master of and we are dir of
+ * . dlm_master_lookup RECOVER_DIR (fix_master 0, from_master 1)
+ *   we either create new rsb setting remote node as master, or find existing
+ *   rsb and set master to be the remote node.
+ *
+ * recover masters, we are finding the new master for resources
+ * . dlm_recover_masters
+ * . recover_master
+ * . dlm_send_rcom_lookup
+ * . receive_rcom_lookup
+ * . dlm_master_lookup RECOVER_MASTER (fix_master 1, from_master 0)
+ */
+
+int dlm_master_lookup(struct dlm_ls *ls, int from_nodeid, char *name, int len,
+		      unsigned int flags, int *r_nodeid, int *result)
+{
+	struct dlm_rsb *r = NULL;
+	uint32_t hash, b;
+	int from_master = (flags & DLM_LU_RECOVER_DIR);
+	int fix_master = (flags & DLM_LU_RECOVER_MASTER);
+	int our_nodeid = dlm_our_nodeid();
+	int dir_nodeid, error, toss_list = 0;
+
+	if (len > DLM_RESNAME_MAXLEN)
+		return -EINVAL;
+
+	if (from_nodeid == our_nodeid) {
+		log_error(ls, "dlm_master_lookup from our_nodeid %d flags %x",
+			  our_nodeid, flags);
+		return -EINVAL;
+	}
+
+	hash = jhash(name, len, 0);
+	b = hash & (ls->ls_rsbtbl_size - 1);
+
+	dir_nodeid = dlm_hash2nodeid(ls, hash);
+	if (dir_nodeid != our_nodeid) {
+		log_error(ls, "dlm_master_lookup from %d dir %d our %d h %x %d",
+			  from_nodeid, dir_nodeid, our_nodeid, hash,
+			  ls->ls_num_nodes);
+		*r_nodeid = -1;
+		return -EINVAL;
+	}
+
+ retry:
+	error = pre_rsb_struct(ls);
+	if (error < 0)
+		return error;
+
+	spin_lock(&ls->ls_rsbtbl[b].lock);
+	error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
+	if (!error) {
+		/* because the rsb is active, we need to lock_rsb before
+		   checking/changing re_master_nodeid */
+
+		hold_rsb(r);
+		spin_unlock(&ls->ls_rsbtbl[b].lock);
+		lock_rsb(r);
+		goto found;
+	}
+
+	error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
+	if (error)
+		goto not_found;
+
+	/* because the rsb is inactive (on toss list), it's not refcounted
+	   and lock_rsb is not used, but is protected by the rsbtbl lock */
+
+	toss_list = 1;
+ found:
+	if (r->res_dir_nodeid != our_nodeid) {
+		/* should not happen, but may as well fix it and carry on */
+		log_error(ls, "dlm_master_lookup res_dir %d our %d %s",
+			  r->res_dir_nodeid, our_nodeid, r->res_name);
+		r->res_dir_nodeid = our_nodeid;
+	}
+
+	if (fix_master && dlm_is_removed(ls, r->res_master_nodeid)) {
+		/* Recovery uses this function to set a new master when
+		   the previous master failed.  Setting NEW_MASTER will
+		   force dlm_recover_masters to call recover_master on this
+		   rsb even though the res_nodeid is no longer removed. */
+
+		r->res_master_nodeid = from_nodeid;
+		r->res_nodeid = from_nodeid;
+		rsb_set_flag(r, RSB_NEW_MASTER);
+
+		if (toss_list) {
+			/* I don't think we should ever find it on toss list. */
+			log_error(ls, "dlm_master_lookup fix_master on toss");
+			dlm_dump_rsb(r);
+		}
+	}
+
+	if (from_master && (r->res_master_nodeid != from_nodeid)) {
+		/* this will happen if from_nodeid became master during
+		   a previous recovery cycle, and we aborted the previous
+		   cycle before recovering this master value */
+
+		log_limit(ls, "dlm_master_lookup from_master %d "
+			  "master_nodeid %d res_nodeid %d first %x %s",
+			  from_nodeid, r->res_master_nodeid, r->res_nodeid,
+			  r->res_first_lkid, r->res_name);
+
+		if (r->res_master_nodeid == our_nodeid) {
+			log_error(ls, "from_master %d our_master", from_nodeid);
+			dlm_dump_rsb(r);
+			dlm_send_rcom_lookup_dump(r, from_nodeid);
+			goto out_found;
+		}
+
+		r->res_master_nodeid = from_nodeid;
+		r->res_nodeid = from_nodeid;
+		rsb_set_flag(r, RSB_NEW_MASTER);
+	}
+
+	if (!r->res_master_nodeid) {
+		/* this will happen if recovery happens while we're looking
+		   up the master for this rsb */
+
+		log_debug(ls, "dlm_master_lookup master 0 to %d first %x %s",
+			  from_nodeid, r->res_first_lkid, r->res_name);
+		r->res_master_nodeid = from_nodeid;
+		r->res_nodeid = from_nodeid;
+	}
+
+	if (!from_master && !fix_master &&
+	    (r->res_master_nodeid == from_nodeid)) {
+		/* this can happen when the master sends remove, the dir node
+		   finds the rsb on the keep list and ignores the remove,
+		   and the former master sends a lookup */
+
+		log_limit(ls, "dlm_master_lookup from master %d flags %x "
+			  "first %x %s", from_nodeid, flags,
+			  r->res_first_lkid, r->res_name);
+	}
+
+ out_found:
+	*r_nodeid = r->res_master_nodeid;
+	if (result)
+		*result = DLM_LU_MATCH;
+
+	if (toss_list) {
+		r->res_toss_time = jiffies;
+		/* the rsb was inactive (on toss list) */
+		spin_unlock(&ls->ls_rsbtbl[b].lock);
+	} else {
+		/* the rsb was active */
+		unlock_rsb(r);
+		put_rsb(r);
+	}
+	return 0;
+
+ not_found:
+	error = get_rsb_struct(ls, name, len, &r);
+	if (error == -EAGAIN) {
+		spin_unlock(&ls->ls_rsbtbl[b].lock);
+		goto retry;
+	}
+	if (error)
+		goto out_unlock;
+
+	r->res_hash = hash;
+	r->res_bucket = b;
+	r->res_dir_nodeid = our_nodeid;
+	r->res_master_nodeid = from_nodeid;
+	r->res_nodeid = from_nodeid;
+	kref_init(&r->res_ref);
+	r->res_toss_time = jiffies;
+
+	error = rsb_insert(r, &ls->ls_rsbtbl[b].toss);
+	if (error) {
+		/* should never happen */
+		dlm_free_rsb(r);
+		spin_unlock(&ls->ls_rsbtbl[b].lock);
+		goto retry;
+	}
+
+	if (result)
+		*result = DLM_LU_ADD;
+	*r_nodeid = from_nodeid;
+	error = 0;
+ out_unlock:
+	spin_unlock(&ls->ls_rsbtbl[b].lock);
 	return error;
 }
 
···
 	}
 }
 
-/* This is only called to add a reference when the code already holds
-   a valid reference to the rsb, so there's no need for locking. */
-
-static inline void hold_rsb(struct dlm_rsb *r)
+void dlm_dump_rsb_name(struct dlm_ls *ls, char *name, int len)
 {
-	kref_get(&r->res_ref);
-}
+	struct dlm_rsb *r = NULL;
+	uint32_t hash, b;
+	int error;
 
-void dlm_hold_rsb(struct dlm_rsb *r)
-{
-	hold_rsb(r);
+	hash = jhash(name, len, 0);
+	b = hash & (ls->ls_rsbtbl_size - 1);
+
+	spin_lock(&ls->ls_rsbtbl[b].lock);
+	error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
+	if (!error)
+		goto out_dump;
+
+	error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
+	if (error)
+		goto out;
+ out_dump:
+	dlm_dump_rsb(r);
+ out:
+	spin_unlock(&ls->ls_rsbtbl[b].lock);
 }
 
 static void toss_rsb(struct kref *kref)
···
 		dlm_free_lvb(r->res_lvbptr);
 		r->res_lvbptr = NULL;
 	}
-}
-
-/* When all references to the rsb are gone it's transferred to
-   the tossed list for later disposal. */
-
-static void put_rsb(struct dlm_rsb *r)
-{
-	struct dlm_ls *ls = r->res_ls;
-	uint32_t bucket = r->res_bucket;
-
-	spin_lock(&ls->ls_rsbtbl[bucket].lock);
-	kref_put(&r->res_ref, toss_rsb);
-	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
-}
-
-void dlm_put_rsb(struct dlm_rsb *r)
-{
-	put_rsb(r);
 }
 
 /* See comment for unhold_lkb */
···
 	return error;
 }
 
-static void dir_remove(struct dlm_rsb *r)
-{
-	int to_nodeid;
-
-	if (dlm_no_directory(r->res_ls))
-		return;
-
-	to_nodeid = dlm_dir_nodeid(r);
-	if (to_nodeid != dlm_our_nodeid())
-		send_remove(r);
-	else
-		dlm_dir_remove_entry(r->res_ls, to_nodeid,
-				     r->res_name, r->res_length);
-}
-
 /* FIXME: make this more efficient */
 
 static int shrink_bucket(struct dlm_ls *ls, int b)
 {
 	struct rb_node *n;
 	struct dlm_rsb *r;
+	int our_nodeid = dlm_our_nodeid();
 	int count = 0, found;
 
 	for (;;) {
···
 		spin_lock(&ls->ls_rsbtbl[b].lock);
 		for (n = rb_first(&ls->ls_rsbtbl[b].toss); n; n = rb_next(n)) {
 			r = rb_entry(n, struct dlm_rsb, res_hashnode);
+
+			/* If we're the directory record for this rsb, and
+			   we're not the master of it, then we need to wait
+			   for the master node to send us a dir remove for
+			   before removing the dir record. */
+
+			if (!dlm_no_directory(ls) && !is_master(r) &&
+			    (dlm_dir_nodeid(r) == our_nodeid)) {
+				continue;
+			}
+
 			if (!time_after_eq(jiffies, r->res_toss_time +
 					   dlm_config.ci_toss_secs * HZ))
 				continue;
···
 			rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
 			spin_unlock(&ls->ls_rsbtbl[b].lock);
 
-			if (is_master(r))
-				dir_remove(r);
+			/* We're the master of this rsb but we're not
+			   the directory record, so we need to tell the
+			   dir node to remove the dir record. */
+
+			if (!dlm_no_directory(ls) && is_master(r) &&
+			    (dlm_dir_nodeid(r) != our_nodeid)) {
+				send_remove(r);
+			}
+
 			dlm_free_rsb(r);
 			count++;
 		} else {
···
 
 static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb)
 {
-	struct dlm_ls *ls = r->res_ls;
-	int i, error, dir_nodeid, ret_nodeid, our_nodeid = dlm_our_nodeid();
+	int our_nodeid = dlm_our_nodeid();
 
 	if (rsb_flag(r, RSB_MASTER_UNCERTAIN)) {
 		rsb_clear_flag(r, RSB_MASTER_UNCERTAIN);
···
 		return 1;
 	}
 
-	if (r->res_nodeid == 0) {
+	if (r->res_master_nodeid == our_nodeid) {
 		lkb->lkb_nodeid = 0;
 		return 0;
 	}
 
-	if (r->res_nodeid > 0) {
-		lkb->lkb_nodeid = r->res_nodeid;
+	if (r->res_master_nodeid) {
+		lkb->lkb_nodeid = r->res_master_nodeid;
 		return 0;
 	}
 
-	DLM_ASSERT(r->res_nodeid == -1, dlm_dump_rsb(r););
-
-	dir_nodeid = dlm_dir_nodeid(r);
-
-	if (dir_nodeid != our_nodeid) {
-		r->res_first_lkid = lkb->lkb_id;
-		send_lookup(r, lkb);
-		return 1;
-	}
-
-	for (i = 0; i < 2; i++) {
-		/* It's possible for dlm_scand to remove an old rsb for
-		   this same resource from the toss list, us to create
-		   a new one, look up the master locally, and find it
-		   already exists just before dlm_scand does the
-		   dir_remove() on the previous rsb. */
-
-		error = dlm_dir_lookup(ls, our_nodeid, r->res_name,
-				       r->res_length, &ret_nodeid);
-		if (!error)
-			break;
-		log_debug(ls, "dir_lookup error %d %s", error, r->res_name);
-		schedule();
-	}
-	if (error && error != -EEXIST)
-		return error;
-
-	if (ret_nodeid == our_nodeid) {
-		r->res_first_lkid = 0;
+	if (dlm_dir_nodeid(r) == our_nodeid) {
+		/* This is a somewhat unusual case; find_rsb will usually
+		   have set res_master_nodeid when dir nodeid is local, but
+		   there are cases where we become the dir node after we've
+		   past find_rsb and go through _request_lock again.
+		   confirm_master() or process_lookup_list() needs to be
+		   called after this. */
+		log_debug(r->res_ls, "set_master %x self master %d dir %d %s",
+			  lkb->lkb_id, r->res_master_nodeid, r->res_dir_nodeid,
+			  r->res_name);
+		r->res_master_nodeid = our_nodeid;
 		r->res_nodeid = 0;
 		lkb->lkb_nodeid = 0;
-	} else {
-		r->res_first_lkid = lkb->lkb_id;
-		r->res_nodeid = ret_nodeid;
-		lkb->lkb_nodeid = ret_nodeid;
+		return 0;
 	}
-	return 0;
+
+	r->res_first_lkid = lkb->lkb_id;
+	send_lookup(r, lkb);
+	return 1;
 }
 
 static void process_lookup_list(struct dlm_rsb *r)
···
 }
 
 /* returns: 0 did nothing, -DLM_ECANCEL canceled lock */
- 
+
 static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
 {
 	int error;
···
 
 	error = validate_lock_args(ls, lkb, args);
 	if (error)
-		goto out;
+		return error;
 
-	error = find_rsb(ls, name, len, R_CREATE, &r);
+	error = find_rsb(ls, name, len, 0, R_REQUEST, &r);
 	if (error)
-		goto out;
+		return error;
 
 	lock_rsb(r);
 
···
 
 	unlock_rsb(r);
 	put_rsb(r);
-
- out:
 	return error;
 }
 
···
 {
 	struct dlm_lkb *lkb;
 	struct dlm_rsb *r;
+	int from_nodeid;
 	int error, namelen;
+
+	from_nodeid = ms->m_header.h_nodeid;
 
 	error = create_lkb(ls, &lkb);
 	if (error)
···
 		goto fail;
 	}
 
+	/* The dir node is the authority on whether we are the master
+	   for this rsb or not, so if the master sends us a request, we should
+	   recreate the rsb if we've destroyed it.   This race happens when we
+	   send a remove message to the dir node at the same time that the dir
+	   node sends us a request for the rsb. */
+
 	namelen = receive_extralen(ms);
 
-	error = find_rsb(ls, ms->m_extra, namelen, R_MASTER, &r);
+	error = find_rsb(ls, ms->m_extra, namelen, from_nodeid,
+			 R_RECEIVE_REQUEST, &r);
 	if (error) {
 		__put_lkb(ls, lkb);
 		goto fail;
 	}
 
 	lock_rsb(r);
+
+	if (r->res_master_nodeid != dlm_our_nodeid()) {
+		error = validate_master_nodeid(ls, r, from_nodeid);
+		if (error) {
+			unlock_rsb(r);
+			put_rsb(r);
+			__put_lkb(ls, lkb);
+			goto fail;
+		}
+	}
 
 	attach_lkb(r, lkb);
 	error = do_request(r, lkb);
···
 	return 0;
 
  fail:
+	/* TODO: instead of returning ENOTBLK, add the lkb to res_lookup
+	   and do this receive_request again from process_lookup_list once
+	   we get the lookup reply.  This would avoid a many repeated
+	   ENOTBLK request failures when the lookup reply designating us
+	   as master is delayed. */
+
+	/* We could repeatedly return -EBADR here if our send_remove() is
+	   delayed in being sent/arriving/being processed on the dir node.
+	   Another node would repeatedly lookup up the master, and the dir
+	   node would continue returning our nodeid until our send_remove
+	   took effect. */
+
+	if (error != -ENOTBLK) {
+		log_limit(ls, "receive_request %x from %d %d",
+			  ms->m_lkid, from_nodeid, error);
+	}
+
 	setup_stub_lkb(ls, ms);
 	send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
 	return error;
···
 
 static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms)
 {
-	int len, error, ret_nodeid, dir_nodeid, from_nodeid, our_nodeid;
+	int len, error, ret_nodeid, from_nodeid, our_nodeid;
 
 	from_nodeid = ms->m_header.h_nodeid;
 	our_nodeid = dlm_our_nodeid();
 
 	len = receive_extralen(ms);
 
-	dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
-	if (dir_nodeid != our_nodeid) {
-		log_error(ls, "lookup dir_nodeid %d from %d",
-			  dir_nodeid, from_nodeid);
-		error = -EINVAL;
-		ret_nodeid = -1;
-		goto out;
-	}
-
-	error = dlm_dir_lookup(ls, from_nodeid, ms->m_extra, len, &ret_nodeid);
+	error = dlm_master_lookup(ls, from_nodeid, ms->m_extra, len, 0,
+				  &ret_nodeid, NULL);
 
 	/* Optimization: we're master so treat lookup as a request */
 	if (!error && ret_nodeid == our_nodeid) {
 		receive_request(ls, ms);
 		return;
 	}
- out:
 	send_lookup_reply(ls, ms, ret_nodeid, error);
 }
 
 static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms)
 {
-	int len, dir_nodeid, from_nodeid;
+	char name[DLM_RESNAME_MAXLEN+1];
+	struct dlm_rsb *r;
+	uint32_t hash, b;
+	int rv, len, dir_nodeid, from_nodeid;
 
 	from_nodeid = ms->m_header.h_nodeid;
 
 	len = receive_extralen(ms);
 
-	dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
-	if (dir_nodeid != dlm_our_nodeid()) {
-		log_error(ls, "remove dir entry dir_nodeid %d from %d",
-			  dir_nodeid, from_nodeid);
+	if (len > DLM_RESNAME_MAXLEN) {
+		log_error(ls, "receive_remove from %d bad len %d",
+			  from_nodeid, len);
 		return;
 	}
 
-	dlm_dir_remove_entry(ls, from_nodeid, ms->m_extra, len);
+	dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash);
+	if (dir_nodeid != dlm_our_nodeid()) {
+		log_error(ls, "receive_remove from %d bad nodeid %d",
+			  from_nodeid, dir_nodeid);
+		return;
+	}
+
+	/* Look for name on rsbtbl.toss, if it's there, kill it.
+	   If it's on rsbtbl.keep, it's being used, and we should ignore this
+	   message.  This is an expected race between the dir node sending a
+	   request to the master node at the same time as the master node sends
+	   a remove to the dir node.  The resolution to that race is for the
+	   dir node to ignore the remove message, and the master node to
+	   recreate the master rsb when it gets a request from the dir node for
+	   an rsb it doesn't have. */
+
+	memset(name, 0, sizeof(name));
+	memcpy(name, ms->m_extra, len);
+
+	hash = jhash(name, len, 0);
+	b = hash & (ls->ls_rsbtbl_size - 1);
+
+	spin_lock(&ls->ls_rsbtbl[b].lock);
+
+	rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
+	if (rv) {
+		/* verify the rsb is on keep list per comment above */
+		rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
+		if (rv) {
+			/* should not happen */
+			log_error(ls, "receive_remove from %d not found %s",
+				  from_nodeid, name);
+			spin_unlock(&ls->ls_rsbtbl[b].lock);
+			return;
+		}
+		if (r->res_master_nodeid != from_nodeid) {
+			/* should not happen */
+			log_error(ls, "receive_remove keep from %d master %d",
+				  from_nodeid, r->res_master_nodeid);
+			dlm_print_rsb(r);
+			spin_unlock(&ls->ls_rsbtbl[b].lock);
+			return;
+		}
+
+		log_debug(ls, "receive_remove from %d master %d first %x %s",
+			  from_nodeid, r->res_master_nodeid, r->res_first_lkid,
+			  name);
+		spin_unlock(&ls->ls_rsbtbl[b].lock);
+		return;
+	}
+
+	if (r->res_master_nodeid != from_nodeid) {
+		log_error(ls, "receive_remove toss from %d master %d",
+			  from_nodeid, r->res_master_nodeid);
+		dlm_print_rsb(r);
+		spin_unlock(&ls->ls_rsbtbl[b].lock);
+		return;
+	}
+
+	if (kref_put(&r->res_ref, kill_rsb)) {
+		rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
+		spin_unlock(&ls->ls_rsbtbl[b].lock);
+		dlm_free_rsb(r);
+	} else {
+		log_error(ls, "receive_remove from %d rsb ref error",
+			  from_nodeid);
+		dlm_print_rsb(r);
+		spin_unlock(&ls->ls_rsbtbl[b].lock);
+	}
 }
 
 static void receive_purge(struct dlm_ls *ls, struct dlm_message *ms)
···
 	struct dlm_lkb *lkb;
 	struct dlm_rsb *r;
 	int error, mstype, result;
+	int from_nodeid = ms->m_header.h_nodeid;
 
 	error = find_lkb(ls, ms->m_remid, &lkb);
 	if (error)
···
 	error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY);
 	if (error) {
 		log_error(ls, "receive_request_reply %x remote %d %x result %d",
-			  lkb->lkb_id, ms->m_header.h_nodeid, ms->m_lkid,
-			  ms->m_result);
+			  lkb->lkb_id, from_nodeid, ms->m_lkid, ms->m_result);
 		dlm_dump_rsb(r);
 		goto out;
 	}
···
 	/* Optimization: the dir node was also the master, so it took our
 	   lookup as a request and sent request reply instead of lookup reply */
 	if (mstype == DLM_MSG_LOOKUP) {
-		r->res_nodeid = ms->m_header.h_nodeid;
-		lkb->lkb_nodeid = r->res_nodeid;
+		r->res_master_nodeid = from_nodeid;
+		r->res_nodeid = from_nodeid;
+		lkb->lkb_nodeid = from_nodeid;
 	}
 
 	/* this is the value returned from do_request() on the master */
···
 	case -EBADR:
 	case -ENOTBLK:
 		/* find_rsb failed to find rsb or rsb wasn't master */
-		log_debug(ls, "receive_request_reply %x %x master diff %d %d",
-			  lkb->lkb_id, lkb->lkb_flags, r->res_nodeid, result);
-		r->res_nodeid = -1;
-		lkb->lkb_nodeid = -1;
+		log_limit(ls, "receive_request_reply %x from %d %d "
+			  "master %d dir %d first %x %s", lkb->lkb_id,
+			  from_nodeid, result, r->res_master_nodeid,
+			  r->res_dir_nodeid, r->res_first_lkid, r->res_name);
+
+		if (r->res_dir_nodeid != dlm_our_nodeid() &&
+		    r->res_master_nodeid != dlm_our_nodeid()) {
+			/* cause _request_lock->set_master->send_lookup */
+			r->res_master_nodeid = 0;
+			r->res_nodeid = -1;
+			lkb->lkb_nodeid = -1;
+		}
 
 		if (is_overlap(lkb)) {
 			/* we'll ignore error in cancel/unlock reply */
 			queue_cast_overlap(r, lkb);
 			confirm_master(r, result);
 			unhold_lkb(lkb); /* undoes create_lkb() */
-		} else
+		} else {
 			_request_lock(r, lkb);
+
+			if (r->res_master_nodeid == dlm_our_nodeid())
+				confirm_master(r, 0);
+		}
 		break;
 
 	default:
···
 	struct dlm_lkb *lkb;
 	struct dlm_rsb *r;
 	int error, ret_nodeid;
+	int do_lookup_list = 0;
 
 	error = find_lkb(ls, ms->m_lkid, &lkb);
 	if (error) {
···
 		return;
 	}
 
-	/* ms->m_result is the value returned by dlm_dir_lookup on dir node
+	/* ms->m_result is the value returned by dlm_master_lookup on dir node
 	   FIXME: will a non-zero error ever be returned? */
 
 	r = lkb->lkb_resource;
···
 		goto out;
 
 	ret_nodeid = ms->m_nodeid;
+
+	/* We sometimes receive a request from the dir node for this
+	   rsb before we've received the dir node's loookup_reply for it.
+	   The request from the dir node implies we're the master, so we set
+	   ourself as master in receive_request_reply, and verify here that
+	   we are indeed the master. */
+
+	if (r->res_master_nodeid && (r->res_master_nodeid != ret_nodeid)) {
+		/* This should never happen */
+		log_error(ls, "receive_lookup_reply %x from %d ret %d "
+			  "master %d dir %d our %d first %x %s",
+			  lkb->lkb_id, ms->m_header.h_nodeid, ret_nodeid,
+			  r->res_master_nodeid, r->res_dir_nodeid,
+			  dlm_our_nodeid(), r->res_first_lkid, r->res_name);
+	}
+
 	if (ret_nodeid == dlm_our_nodeid()) {
+		r->res_master_nodeid = ret_nodeid;
 		r->res_nodeid = 0;
-		ret_nodeid = 0;
+		do_lookup_list = 1;
 		r->res_first_lkid = 0;
+	} else if (ret_nodeid == -1) {
+		/* the remote node doesn't believe it's the dir node */
+		log_error(ls, "receive_lookup_reply %x from %d bad ret_nodeid",
+			  lkb->lkb_id, ms->m_header.h_nodeid);
+		r->res_master_nodeid = 0;
+		r->res_nodeid = -1;
+		lkb->lkb_nodeid = -1;
 	} else {
-		/* set_master() will copy res_nodeid to lkb_nodeid */
+		/* set_master() will set lkb_nodeid from r */
+		r->res_master_nodeid = ret_nodeid;
 		r->res_nodeid = ret_nodeid;
 	}
 
···
 	_request_lock(r, lkb);
 
  out_list:
-	if (!ret_nodeid)
+	if (do_lookup_list)
 		process_lookup_list(r);
  out:
 	unlock_rsb(r);
···
 	int error = 0, noent = 0;
 
 	if (!dlm_is_member(ls, ms->m_header.h_nodeid)) {
-		log_debug(ls, "ignore non-member message %d from %d %x %x %d",
+		log_limit(ls, "receive %d from non-member %d %x %x %d",
 			  ms->m_type, ms->m_header.h_nodeid, ms->m_lkid,
 			  ms->m_remid, ms->m_result);
 		return;
···
 				int nodeid)
 {
 	if (dlm_locking_stopped(ls)) {
+		/* If we were a member of this lockspace, left, and rejoined,
+		   other nodes may still be sending us messages from the
+		   lockspace generation before we left. */
+		if (!ls->ls_generation) {
+			log_limit(ls, "receive %d from %d ignore old gen",
+				  ms->m_type, nodeid);
+			return;
+		}
+
 		dlm_add_requestqueue(ls, nodeid, ms);
 	} else {
 		dlm_wait_requestqueue(ls);
···
 	struct dlm_rsb *r;
 	struct dlm_lkb *lkb;
 	uint32_t remid = 0;
+	int from_nodeid = rc->rc_header.h_nodeid;
 	int error;
 
 	if (rl->rl_parent_lkid) {
···
 	   we make ourselves master, dlm_recover_masters() won't touch the
 	   MSTCPY locks we've received early. */
 
-	error = find_rsb(ls, rl->rl_name, le16_to_cpu(rl->rl_namelen), 0, &r);
+	error = find_rsb(ls, rl->rl_name, le16_to_cpu(rl->rl_namelen),
+			 from_nodeid, R_RECEIVE_RECOVER, &r);
 	if (error)
 		goto out;
 
-	if (dlm_no_directory(ls) && (dlm_dir_nodeid(r) != dlm_our_nodeid())) {
-		log_error(ls, "dlm_recover_master_copy remote %d %x not dir",
-			  rc->rc_header.h_nodeid, remid);
-		error = -EBADR;
-		put_rsb(r);
-		goto out;
-	}
-
 	lock_rsb(r);
 
-	lkb = search_remid(r, rc->rc_header.h_nodeid, remid);
+	if (dlm_no_directory(ls) && (dlm_dir_nodeid(r) != dlm_our_nodeid())) {
+		log_error(ls, "dlm_recover_master_copy remote %d %x not dir",
+			  from_nodeid, remid);
+		error = -EBADR;
+		goto out_unlock;
+	}
+
+	lkb = search_remid(r, from_nodeid, remid);
 	if (lkb) {
 		error = -EEXIST;
 		goto out_remid;
···
  out:
 	if (error && error != -EEXIST)
 		log_debug(ls, "dlm_recover_master_copy remote %d %x error %d",
-			  rc->rc_header.h_nodeid, remid, error);
+			  from_nodeid, remid, error);
 	rl->rl_result = cpu_to_le32(error);
 	return error;
 }

fs/dlm/lock.h

···
 #define __LOCK_DOT_H__
 
 void dlm_dump_rsb(struct dlm_rsb *r);
+void dlm_dump_rsb_name(struct dlm_ls *ls, char *name, int len);
 void dlm_print_lkb(struct dlm_lkb *lkb);
 void dlm_receive_message_saved(struct dlm_ls *ls, struct dlm_message *ms,
 			       uint32_t saved_seq);
···
 void dlm_scan_waiters(struct dlm_ls *ls);
 void dlm_scan_timeout(struct dlm_ls *ls);
 void dlm_adjust_timeouts(struct dlm_ls *ls);
+int dlm_master_lookup(struct dlm_ls *ls, int nodeid, char *name, int len,
+		      unsigned int flags, int *r_nodeid, int *result);
 
 int dlm_search_rsb_tree(struct rb_root *tree, char *name, int len,
-			unsigned int flags, struct dlm_rsb **r_ret);
+			struct dlm_rsb **r_ret);
 
 void dlm_recover_purge(struct dlm_ls *ls);
 void dlm_purge_mstcpy_locks(struct dlm_rsb *r);

fs/dlm/lockspace.c

···
 	idr_init(&ls->ls_lkbidr);
 	spin_lock_init(&ls->ls_lkbidr_spin);
 
-	size = dlm_config.ci_dirtbl_size;
-	ls->ls_dirtbl_size = size;
-
-	ls->ls_dirtbl = vmalloc(sizeof(struct dlm_dirtable) * size);
-	if (!ls->ls_dirtbl)
-		goto out_lkbfree;
-	for (i = 0; i < size; i++) {
-		INIT_LIST_HEAD(&ls->ls_dirtbl[i].list);
-		spin_lock_init(&ls->ls_dirtbl[i].lock);
-	}
-
 	INIT_LIST_HEAD(&ls->ls_waiters);
 	mutex_init(&ls->ls_waiters_mutex);
 	INIT_LIST_HEAD(&ls->ls_orphans);
···
 
 	ls->ls_recover_buf = kmalloc(dlm_config.ci_buffer_size, GFP_NOFS);
 	if (!ls->ls_recover_buf)
-		goto out_dirfree;
+		goto out_lkbfree;
 
 	ls->ls_slot = 0;
 	ls->ls_num_slots = 0;
···
 	list_del(&ls->ls_list);
 	spin_unlock(&lslist_lock);
 	kfree(ls->ls_recover_buf);
- out_dirfree:
-	vfree(ls->ls_dirtbl);
  out_lkbfree:
 	idr_destroy(&ls->ls_lkbidr);
 	vfree(ls->ls_rsbtbl);
···
 	kfree(ls->ls_recover_buf);
 
 	/*
-	 * Free direntry structs.
-	 */
-
-	dlm_dir_clear(ls);
-	vfree(ls->ls_dirtbl);
-
-	/*
 	 * Free all lkb's in idr
 	 */
 
···
 
 	dlm_purge_requestqueue(ls);
 	kfree(ls->ls_recover_args);
-	dlm_clear_free_entries(ls);
 	dlm_clear_members(ls);
 	dlm_clear_members_gone(ls);
 	kfree(ls->ls_node_array);

fs/dlm/rcom.c

···
 #include "memory.h"
 #include "lock.h"
 #include "util.h"
-#include "member.h"
-
 
 static int rcom_response(struct dlm_ls *ls)
 {
···
 	struct dlm_rcom *rc;
 	struct dlm_mhandle *mh;
 	int error = 0;
-	int max_size = dlm_config.ci_buffer_size - sizeof(struct dlm_rcom);
 
 	ls->ls_recover_nodeid = nodeid;
-
-	if (nodeid == dlm_our_nodeid()) {
-		ls->ls_recover_buf->rc_header.h_length =
-			dlm_config.ci_buffer_size;
-		dlm_copy_master_names(ls, last_name, last_len,
-		                      ls->ls_recover_buf->rc_buf,
-		                      max_size, nodeid);
-		goto out;
-	}
 
 	error = create_rcom(ls, nodeid, DLM_RCOM_NAMES, last_len, &rc, &mh);
 	if (error)
···
 	return error;
 }
 
+int dlm_send_rcom_lookup_dump(struct dlm_rsb *r, int to_nodeid)
+{
+	struct dlm_rcom *rc;
+	struct dlm_mhandle *mh;
+	struct dlm_ls *ls = r->res_ls;
+	int error;
+
+	error = create_rcom(ls, to_nodeid, DLM_RCOM_LOOKUP, r->res_length,
+			    &rc, &mh);
+	if (error)
+		goto out;
+	memcpy(rc->rc_buf, r->res_name, r->res_length);
+	rc->rc_id = 0xFFFFFFFF;
+
+	send_rcom(ls, mh, rc);
+ out:
+	return error;
+}
+
 static void receive_rcom_lookup(struct dlm_ls *ls, struct dlm_rcom *rc_in)
 {
 	struct dlm_rcom *rc;
···
 	if (error)
 		return;
 
-	error = dlm_dir_lookup(ls, nodeid, rc_in->rc_buf, len, &ret_nodeid);
+	if (rc_in->rc_id == 0xFFFFFFFF) {
+		log_error(ls, "receive_rcom_lookup dump from %d", nodeid);
+		dlm_dump_rsb_name(ls, rc_in->rc_buf, len);
+		return;
+	}
+
+	error = dlm_master_lookup(ls, nodeid, rc_in->rc_buf, len,
+				  DLM_LU_RECOVER_MASTER, &ret_nodeid, NULL);
 	if (error)
 		ret_nodeid = error;
 	rc->rc_result = ret_nodeid;
···
 	return 0;
 }
 
+/*
+ * Ignore messages for stage Y before we set
+ * recover_status bit for stage X:
+ *
+ * recover_status = 0
+ *
+ * dlm_recover_members()
+ * - send nothing
+ * - recv nothing
+ * - ignore NAMES, NAMES_REPLY
+ * - ignore LOOKUP, LOOKUP_REPLY
+ * - ignore LOCK, LOCK_REPLY
+ *
+ * recover_status |= NODES
+ *
+ * dlm_recover_members_wait()
+ *
+ * dlm_recover_directory()
+ * - send NAMES
+ * - recv NAMES_REPLY
+ * - ignore LOOKUP, LOOKUP_REPLY
+ * - ignore LOCK, LOCK_REPLY
+ *
+ * recover_status |= DIR
+ *
+ * dlm_recover_directory_wait()
+ *
+ * dlm_recover_masters()
+ * - send LOOKUP
+ * - recv LOOKUP_REPLY
+ *
+ * dlm_recover_locks()
+ * - send LOCKS
+ * - recv LOCKS_REPLY
+ *
+ * recover_status |= LOCKS
+ *
+ * dlm_recover_locks_wait()
+ *
+ * recover_status |= DONE
+ */
+
 /* Called by dlm_recv; corresponds to dlm_receive_message() but special
    recovery-only comms are sent through here. */
 
 void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
 {
 	int lock_size = sizeof(struct dlm_rcom) + sizeof(struct rcom_lock);
-	int stop, reply = 0, lock = 0;
+	int stop, reply = 0, names = 0, lookup = 0, lock = 0;
 	uint32_t status;
 	uint64_t seq;
 
 	switch (rc->rc_type) {
+	case DLM_RCOM_STATUS_REPLY:
+		reply = 1;
+		break;
+	case DLM_RCOM_NAMES:
+		names = 1;
+		break;
+	case DLM_RCOM_NAMES_REPLY:
+		names = 1;
+		reply = 1;
+		break;
+	case DLM_RCOM_LOOKUP:
+		lookup = 1;
+		break;
+	case DLM_RCOM_LOOKUP_REPLY:
+		lookup = 1;
+		reply = 1;
+		break;
 	case DLM_RCOM_LOCK:
 		lock = 1;
 		break;
···
 		lock = 1;
 		reply = 1;
 		break;
-	case DLM_RCOM_STATUS_REPLY:
-	case DLM_RCOM_NAMES_REPLY:
-	case DLM_RCOM_LOOKUP_REPLY:
-		reply = 1;
 	};
 
 	spin_lock(&ls->ls_recover_lock);
···
 	seq = ls->ls_recover_seq;
 	spin_unlock(&ls->ls_recover_lock);
 
-	if ((stop && (rc->rc_type != DLM_RCOM_STATUS)) ||
-	    (reply && (rc->rc_seq_reply != seq)) ||
-	    (lock && !(status & DLM_RS_DIR))) {
-		log_limit(ls, "dlm_receive_rcom ignore msg %d "
-			  "from %d %llu %llu recover seq %llu sts %x gen %u",
-			   rc->rc_type,
-			   nodeid,
-			   (unsigned long long)rc->rc_seq,
-			   (unsigned long long)rc->rc_seq_reply,
-			   (unsigned long long)seq,
-			   status, ls->ls_generation);
-		goto out;
-	}
+	if (stop && (rc->rc_type != DLM_RCOM_STATUS))
+		goto ignore;
+
+	if (reply && (rc->rc_seq_reply != seq))
+		goto ignore;
+
+	if (!(status & DLM_RS_NODES) && (names || lookup || lock))
+		goto ignore;
+
+	if (!(status & DLM_RS_DIR) && (lookup || lock))
+		goto ignore;
 
 	switch (rc->rc_type) {
 	case DLM_RCOM_STATUS:
···
 	default:
 		log_error(ls, "receive_rcom bad type %d", rc->rc_type);
 	}
-out:
+	return;
+
+ignore:
+	log_limit(ls, "dlm_receive_rcom ignore msg %d "
+		  "from %d %llu %llu recover seq %llu sts %x gen %u",
+		   rc->rc_type,
+		   nodeid,
+		   (unsigned long long)rc->rc_seq,
+		   (unsigned long long)rc->rc_seq_reply,
+		   (unsigned long long)seq,
+		   status, ls->ls_generation);
 	return;
 Eshort:
-	log_error(ls, "recovery message %x from %d is too short",
-			  rc->rc_type, nodeid);
+	log_error(ls, "recovery message %d from %d is too short",
+		  rc->rc_type, nodeid);
 }
 

fs/dlm/rcom.h

···
 int dlm_rcom_status(struct dlm_ls *ls, int nodeid, uint32_t status_flags);
 int dlm_rcom_names(struct dlm_ls *ls, int nodeid, char *last_name,int last_len);
 int dlm_send_rcom_lookup(struct dlm_rsb *r, int dir_nodeid);
+int dlm_send_rcom_lookup_dump(struct dlm_rsb *r, int to_nodeid);
 int dlm_send_rcom_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
 void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid);
 int dlm_send_ls_not_ready(int nodeid, struct dlm_rcom *rc_in);

fs/dlm/recover.c

···
  * rsb's to consider.
  */
 
-static void set_new_master(struct dlm_rsb *r, int nodeid)
+static void set_new_master(struct dlm_rsb *r)
 {
-	r->res_nodeid = nodeid;
 	set_master_lkbs(r);
 	rsb_set_flag(r, RSB_NEW_MASTER);
 	rsb_set_flag(r, RSB_NEW_MASTER2);
···
 /*
  * We do async lookups on rsb's that need new masters.  The rsb's
  * waiting for a lookup reply are kept on the recover_list.
+ *
+ * Another node recovering the master may have sent us a rcom lookup,
+ * and our dlm_master_lookup() set it as the new master, along with
+ * NEW_MASTER so that we'll recover it here (this implies dir_nodeid
+ * equals our_nodeid below).
  */
 
-static int recover_master(struct dlm_rsb *r)
+static int recover_master(struct dlm_rsb *r, unsigned int *count)
 {
 	struct dlm_ls *ls = r->res_ls;
-	int error, ret_nodeid;
-	int our_nodeid = dlm_our_nodeid();
-	int dir_nodeid = dlm_dir_nodeid(r);
+	int our_nodeid, dir_nodeid;
+	int is_removed = 0;
+	int error;
+
+	if (is_master(r))
+		return 0;
+
+	is_removed = dlm_is_removed(ls, r->res_nodeid);
+
+	if (!is_removed && !rsb_flag(r, RSB_NEW_MASTER))
+		return 0;
+
+	our_nodeid = dlm_our_nodeid();
+	dir_nodeid = dlm_dir_nodeid(r);
 
 	if (dir_nodeid == our_nodeid) {
-		error = dlm_dir_lookup(ls, our_nodeid, r->res_name,
-				       r->res_length, &ret_nodeid);
-		if (error)
-			log_error(ls, "recover dir lookup error %d", error);
+		if (is_removed) {
+			r->res_master_nodeid = our_nodeid;
+			r->res_nodeid = 0;
+		}
 
-		if (ret_nodeid == our_nodeid)
-			ret_nodeid = 0;
-		lock_rsb(r);
-		set_new_master(r, ret_nodeid);
-		unlock_rsb(r);
+		/* set master of lkbs to ourself when is_removed, or to
+		   another new master which we set along with NEW_MASTER
+		   in dlm_master_lookup */
+		set_new_master(r);
+		error = 0;
 	} else {
 		recover_list_add(r);
 		error = dlm_send_rcom_lookup(r, dir_nodeid);
 	}
 
+	(*count)++;
 	return error;
 }
 
···
  * resent.
  */
 
-static int recover_master_static(struct dlm_rsb *r)
+static int recover_master_static(struct dlm_rsb *r, unsigned int *count)
 {
 	int dir_nodeid = dlm_dir_nodeid(r);
 	int new_master = dir_nodeid;
···
 	if (dir_nodeid == dlm_our_nodeid())
 		new_master = 0;
 
-	lock_rsb(r);
 	dlm_purge_mstcpy_locks(r);
-	set_new_master(r, new_master);
-	unlock_rsb(r);
-	return 1;
+	r->res_master_nodeid = dir_nodeid;
+	r->res_nodeid = new_master;
+	set_new_master(r);
+	(*count)++;
+	return 0;
 }
 
 /*
···
 int dlm_recover_masters(struct dlm_ls *ls)
 {
 	struct dlm_rsb *r;
-	int error = 0, count = 0;
+	unsigned int total = 0;
+	unsigned int count = 0;
+	int nodir = dlm_no_directory(ls);
+	int error;
 
 	log_debug(ls, "dlm_recover_masters");
 
···
 			goto out;
 		}
 
-		if (dlm_no_directory(ls))
-			count += recover_master_static(r);
-		else if (!is_master(r) &&
-			 (dlm_is_removed(ls, r->res_nodeid) ||
-			  rsb_flag(r, RSB_NEW_MASTER))) {
-			recover_master(r);
-			count++;
-		}
+		lock_rsb(r);
+		if (nodir)
+			error = recover_master_static(r, &count);
+		else
+			error = recover_master(r, &count);
+		unlock_rsb(r);
+		cond_resched();
+		total++;
 
-		schedule();
+		if (error) {
+			up_read(&ls->ls_root_sem);
+			goto out;
+		}
 	}
 	up_read(&ls->ls_root_sem);
 
-	log_debug(ls, "dlm_recover_masters %d resources", count);
+	log_debug(ls, "dlm_recover_masters %u of %u", count, total);
 
 	error = dlm_wait_function(ls, &recover_list_empty);
  out:
···
 int dlm_recover_master_reply(struct dlm_ls *ls, struct dlm_rcom *rc)
 {
 	struct dlm_rsb *r;
-	int nodeid;
+	int ret_nodeid, new_master;
 
 	r = recover_list_find(ls, rc->rc_id);
 	if (!r) {
···
 		goto out;
 	}
 
-	nodeid = rc->rc_result;
-	if (nodeid == dlm_our_nodeid())
-		nodeid = 0;
+	ret_nodeid = rc->rc_result;
+
+	if (ret_nodeid == dlm_our_nodeid())
+		new_master = 0;
+	else
+		new_master = ret_nodeid;
 
 	lock_rsb(r);
-	set_new_master(r, nodeid);
+	r->res_master_nodeid = ret_nodeid;
+	r->res_nodeid = new_master;
+	set_new_master(r);
 	unlock_rsb(r);
 	recover_list_del(r);
 
···
 			dlm_hold_rsb(r);
 		}
 
-		/* If we're using a directory, add tossed rsbs to the root
-		   list; they'll have entries created in the new directory,
-		   but no other recovery steps should do anything with them. */
-
-		if (dlm_no_directory(ls)) {
-			spin_unlock(&ls->ls_rsbtbl[i].lock);
-			continue;
-		}
-
-		for (n = rb_first(&ls->ls_rsbtbl[i].toss); n; n = rb_next(n)) {
-			r = rb_entry(n, struct dlm_rsb, res_hashnode);
-			list_add(&r->res_root_list, &ls->ls_root_list);
-			dlm_hold_rsb(r);
-		}
+		if (!RB_EMPTY_ROOT(&ls->ls_rsbtbl[i].toss))
+			log_error(ls, "dlm_create_root_list toss not empty");
 		spin_unlock(&ls->ls_rsbtbl[i].lock);
 	}
  out:
···
 	up_write(&ls->ls_root_sem);
 }
 
-/* If not using a directory, clear the entire toss list, there's no benefit to
-   caching the master value since it's fixed.  If we are using a dir, keep the
-   rsb's we're the master of.  Recovery will add them to the root list and from
-   there they'll be entered in the rebuilt directory. */
-
-void dlm_clear_toss_list(struct dlm_ls *ls)
+void dlm_clear_toss(struct dlm_ls *ls)
 {
 	struct rb_node *n, *next;
-	struct dlm_rsb *rsb;
+	struct dlm_rsb *r;
+	unsigned int count = 0;
 	int i;
 
 	for (i = 0; i < ls->ls_rsbtbl_size; i++) {
 		spin_lock(&ls->ls_rsbtbl[i].lock);
 		for (n = rb_first(&ls->ls_rsbtbl[i].toss); n; n = next) {
-			next = rb_next(n);;
-			rsb = rb_entry(n, struct dlm_rsb, res_hashnode);
-			if (dlm_no_directory(ls) || !is_master(rsb)) {
-				rb_erase(n, &ls->ls_rsbtbl[i].toss);
-				dlm_free_rsb(rsb);
-			}
+			next = rb_next(n);
+			r = rb_entry(n, struct dlm_rsb, res_hashnode);
+			rb_erase(n, &ls->ls_rsbtbl[i].toss);
+			dlm_free_rsb(r);
+			count++;
 		}
 		spin_unlock(&ls->ls_rsbtbl[i].lock);
 	}
+
+	if (count)
+		log_debug(ls, "dlm_clear_toss %u done", count);
 }
 

fs/dlm/recover.h

···
 void dlm_recovered_lock(struct dlm_rsb *r);
 int dlm_create_root_list(struct dlm_ls *ls);
 void dlm_release_root_list(struct dlm_ls *ls);
-void dlm_clear_toss_list(struct dlm_ls *ls);
+void dlm_clear_toss(struct dlm_ls *ls);
 void dlm_recover_rsbs(struct dlm_ls *ls);
 
 #endif				/* __RECOVER_DOT_H__ */

fs/dlm/recoverd.c

···
 
 	dlm_callback_suspend(ls);
 
-	/*
-	 * Free non-master tossed rsb's.  Master rsb's are kept on toss
-	 * list and put on root list to be included in resdir recovery.
-	 */
-
-	dlm_clear_toss_list(ls);
+	dlm_clear_toss(ls);
 
 	/*
 	 * This list of root rsb's will be the basis of most of the recovery
···
 		goto fail;
 	}
 
+	dlm_recover_dir_nodeid(ls);
+
+	ls->ls_recover_dir_sent_res = 0;
+	ls->ls_recover_dir_sent_msg = 0;
 	ls->ls_recover_locks_in = 0;
 
 	dlm_set_recover_status(ls, DLM_RS_NODES);
···
 		log_debug(ls, "dlm_recover_directory_wait error %d", error);
 		goto fail;
 	}
+
+	log_debug(ls, "dlm_recover_directory %u out %u messages",
+		  ls->ls_recover_dir_sent_res, ls->ls_recover_dir_sent_msg);
 
 	/*
 	 * We may have outstanding operations that are waiting for a reply from