[DLM] The core of the DLM for GFS2/CLVM

This is the core of the distributed lock manager which is required
to use GFS2 as a cluster filesystem. It is also used by CLVM and
can be used as a standalone lock manager independantly of either
of these two projects.

It implements VAX-style locking modes.

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

1 files changed, 787 insertions, 0 deletions

diff --git a/fs/dlm/config.c b/fs/dlm/config.c
new file mode 100644
index 00000000000..024ace9973a
--- /dev/null
+++ b/fs/dlm/config.c
@@ -0,0 +1,787 @@
+/******************************************************************************
+*******************************************************************************
+**
+**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
+**  Copyright (C) 2004-2005 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
+**  of the GNU General Public License v.2.
+**
+*******************************************************************************
+******************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/configfs.h>
+#include <net/sock.h>
+
+#include "config.h"
+
+/*
+ * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/nodeid
+ * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/weight
+ * /config/dlm/<cluster>/comms/<comm>/nodeid
+ * /config/dlm/<cluster>/comms/<comm>/local
+ * /config/dlm/<cluster>/comms/<comm>/addr
+ * The <cluster> level is useless, but I haven't figured out how to avoid it.
+ */
+
+static struct config_group *space_list;
+static struct config_group *comm_list;
+static struct comm *local_comm;
+
+struct clusters;
+struct cluster;
+struct spaces;
+struct space;
+struct comms;
+struct comm;
+struct nodes;
+struct node;
+
+static struct config_group *make_cluster(struct config_group *, const char *);
+static void drop_cluster(struct config_group *, struct config_item *);
+static void release_cluster(struct config_item *);
+static struct config_group *make_space(struct config_group *, const char *);
+static void drop_space(struct config_group *, struct config_item *);
+static void release_space(struct config_item *);
+static struct config_item *make_comm(struct config_group *, const char *);
+static void drop_comm(struct config_group *, struct config_item *);
+static void release_comm(struct config_item *);
+static struct config_item *make_node(struct config_group *, const char *);
+static void drop_node(struct config_group *, struct config_item *);
+static void release_node(struct config_item *);
+
+static ssize_t show_comm(struct config_item *i, struct configfs_attribute *a,
+			 char *buf);
+static ssize_t store_comm(struct config_item *i, struct configfs_attribute *a,
+			  const char *buf, size_t len);
+static ssize_t show_node(struct config_item *i, struct configfs_attribute *a,
+			 char *buf);
+static ssize_t store_node(struct config_item *i, struct configfs_attribute *a,
+			  const char *buf, size_t len);
+
+static ssize_t comm_nodeid_read(struct comm *cm, char *buf);
+static ssize_t comm_nodeid_write(struct comm *cm, const char *buf, size_t len);
+static ssize_t comm_local_read(struct comm *cm, char *buf);
+static ssize_t comm_local_write(struct comm *cm, const char *buf, size_t len);
+static ssize_t comm_addr_write(struct comm *cm, const char *buf, size_t len);
+static ssize_t node_nodeid_read(struct node *nd, char *buf);
+static ssize_t node_nodeid_write(struct node *nd, const char *buf, size_t len);
+static ssize_t node_weight_read(struct node *nd, char *buf);
+static ssize_t node_weight_write(struct node *nd, const char *buf, size_t len);
+
+enum {
+	COMM_ATTR_NODEID = 0,
+	COMM_ATTR_LOCAL,
+	COMM_ATTR_ADDR,
+};
+
+struct comm_attribute {
+	struct configfs_attribute attr;
+	ssize_t (*show)(struct comm *, char *);
+	ssize_t (*store)(struct comm *, const char *, size_t);
+};
+
+static struct comm_attribute comm_attr_nodeid = {
+	.attr   = { .ca_owner = THIS_MODULE,
+                    .ca_name = "nodeid",
+                    .ca_mode = S_IRUGO | S_IWUSR },
+	.show   = comm_nodeid_read,
+	.store  = comm_nodeid_write,
+};
+
+static struct comm_attribute comm_attr_local = {
+	.attr   = { .ca_owner = THIS_MODULE,
+                    .ca_name = "local",
+                    .ca_mode = S_IRUGO | S_IWUSR },
+	.show   = comm_local_read,
+	.store  = comm_local_write,
+};
+
+static struct comm_attribute comm_attr_addr = {
+	.attr   = { .ca_owner = THIS_MODULE,
+                    .ca_name = "addr",
+                    .ca_mode = S_IRUGO | S_IWUSR },
+	.store  = comm_addr_write,
+};
+
+static struct configfs_attribute *comm_attrs[] = {
+	[COMM_ATTR_NODEID] = &comm_attr_nodeid.attr,
+	[COMM_ATTR_LOCAL] = &comm_attr_local.attr,
+	[COMM_ATTR_ADDR] = &comm_attr_addr.attr,
+	NULL,
+};
+
+enum {
+	NODE_ATTR_NODEID = 0,
+	NODE_ATTR_WEIGHT,
+};
+
+struct node_attribute {
+	struct configfs_attribute attr;
+	ssize_t (*show)(struct node *, char *);
+	ssize_t (*store)(struct node *, const char *, size_t);
+};
+
+static struct node_attribute node_attr_nodeid = {
+	.attr   = { .ca_owner = THIS_MODULE,
+                    .ca_name = "nodeid",
+                    .ca_mode = S_IRUGO | S_IWUSR },
+	.show   = node_nodeid_read,
+	.store  = node_nodeid_write,
+};
+
+static struct node_attribute node_attr_weight = {
+	.attr   = { .ca_owner = THIS_MODULE,
+                    .ca_name = "weight",
+                    .ca_mode = S_IRUGO | S_IWUSR },
+	.show   = node_weight_read,
+	.store  = node_weight_write,
+};
+
+static struct configfs_attribute *node_attrs[] = {
+	[NODE_ATTR_NODEID] = &node_attr_nodeid.attr,
+	[NODE_ATTR_WEIGHT] = &node_attr_weight.attr,
+	NULL,
+};
+
+struct clusters {
+	struct configfs_subsystem subsys;
+};
+
+struct cluster {
+	struct config_group group;
+};
+
+struct spaces {
+	struct config_group ss_group;
+};
+
+struct space {
+	struct config_group group;
+	struct list_head members;
+	struct semaphore members_lock;
+	int members_count;
+};
+
+struct comms {
+	struct config_group cs_group;
+};
+
+struct comm {
+	struct config_item item;
+	int nodeid;
+	int local;
+	int addr_count;
+	struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
+};
+
+struct nodes {
+	struct config_group ns_group;
+};
+
+struct node {
+	struct config_item item;
+	struct list_head list; /* space->members */
+	int nodeid;
+	int weight;
+};
+
+static struct configfs_group_operations clusters_ops = {
+	.make_group = make_cluster,
+	.drop_item = drop_cluster,
+};
+
+static struct configfs_item_operations cluster_ops = {
+	.release = release_cluster,
+};
+
+static struct configfs_group_operations spaces_ops = {
+	.make_group = make_space,
+	.drop_item = drop_space,
+};
+
+static struct configfs_item_operations space_ops = {
+	.release = release_space,
+};
+
+static struct configfs_group_operations comms_ops = {
+	.make_item = make_comm,
+	.drop_item = drop_comm,
+};
+
+static struct configfs_item_operations comm_ops = {
+	.release = release_comm,
+	.show_attribute = show_comm,
+	.store_attribute = store_comm,
+};
+
+static struct configfs_group_operations nodes_ops = {
+	.make_item = make_node,
+	.drop_item = drop_node,
+};
+
+static struct configfs_item_operations node_ops = {
+	.release = release_node,
+	.show_attribute = show_node,
+	.store_attribute = store_node,
+};
+
+static struct config_item_type clusters_type = {
+	.ct_group_ops = &clusters_ops,
+	.ct_owner = THIS_MODULE,
+};
+
+static struct config_item_type cluster_type = {
+	.ct_item_ops = &cluster_ops,
+	.ct_owner = THIS_MODULE,
+};
+
+static struct config_item_type spaces_type = {
+	.ct_group_ops = &spaces_ops,
+	.ct_owner = THIS_MODULE,
+};
+
+static struct config_item_type space_type = {
+	.ct_item_ops = &space_ops,
+	.ct_owner = THIS_MODULE,
+};
+
+static struct config_item_type comms_type = {
+	.ct_group_ops = &comms_ops,
+	.ct_owner = THIS_MODULE,
+};
+
+static struct config_item_type comm_type = {
+	.ct_item_ops = &comm_ops,
+	.ct_attrs = comm_attrs,
+	.ct_owner = THIS_MODULE,
+};
+
+static struct config_item_type nodes_type = {
+	.ct_group_ops = &nodes_ops,
+	.ct_owner = THIS_MODULE,
+};
+
+static struct config_item_type node_type = {
+	.ct_item_ops = &node_ops,
+	.ct_attrs = node_attrs,
+	.ct_owner = THIS_MODULE,
+};
+
+static struct cluster *to_cluster(struct config_item *i)
+{
+	return i ? container_of(to_config_group(i), struct cluster, group):NULL;
+}
+
+static struct space *to_space(struct config_item *i)
+{
+	return i ? container_of(to_config_group(i), struct space, group) : NULL;
+}
+
+static struct comm *to_comm(struct config_item *i)
+{
+	return i ? container_of(i, struct comm, item) : NULL;
+}
+
+static struct node *to_node(struct config_item *i)
+{
+	return i ? container_of(i, struct node, item) : NULL;
+}
+
+static struct config_group *make_cluster(struct config_group *g,
+					 const char *name)
+{
+	struct cluster *cl = NULL;
+	struct spaces *sps = NULL;
+	struct comms *cms = NULL;
+	void *gps = NULL;
+
+	cl = kzalloc(sizeof(struct cluster), GFP_KERNEL);
+	gps = kcalloc(3, sizeof(struct config_group *), GFP_KERNEL);
+	sps = kzalloc(sizeof(struct spaces), GFP_KERNEL);
+	cms = kzalloc(sizeof(struct comms), GFP_KERNEL);
+
+	if (!cl || !gps || !sps || !cms)
+		goto fail;
+
+	config_group_init_type_name(&cl->group, name, &cluster_type);
+	config_group_init_type_name(&sps->ss_group, "spaces", &spaces_type);
+	config_group_init_type_name(&cms->cs_group, "comms", &comms_type);
+
+	cl->group.default_groups = gps;
+	cl->group.default_groups[0] = &sps->ss_group;
+	cl->group.default_groups[1] = &cms->cs_group;
+	cl->group.default_groups[2] = NULL;
+
+	space_list = &sps->ss_group;
+	comm_list = &cms->cs_group;
+	return &cl->group;
+
+ fail:
+	kfree(cl);
+	kfree(gps);
+	kfree(sps);
+	kfree(cms);
+	return NULL;
+}
+
+static void drop_cluster(struct config_group *g, struct config_item *i)
+{
+	struct cluster *cl = to_cluster(i);
+	struct config_item *tmp;
+	int j;
+
+	for (j = 0; cl->group.default_groups[j]; j++) {
+		tmp = &cl->group.default_groups[j]->cg_item;
+		cl->group.default_groups[j] = NULL;
+		config_item_put(tmp);
+	}
+
+	space_list = NULL;
+	comm_list = NULL;
+
+	config_item_put(i);
+}
+
+static void release_cluster(struct config_item *i)
+{
+	struct cluster *cl = to_cluster(i);
+	kfree(cl->group.default_groups);
+	kfree(cl);
+}
+
+static struct config_group *make_space(struct config_group *g, const char *name)
+{
+	struct space *sp = NULL;
+	struct nodes *nds = NULL;
+	void *gps = NULL;
+
+	sp = kzalloc(sizeof(struct space), GFP_KERNEL);
+	gps = kcalloc(2, sizeof(struct config_group *), GFP_KERNEL);
+	nds = kzalloc(sizeof(struct nodes), GFP_KERNEL);
+
+	if (!sp || !gps || !nds)
+		goto fail;
+
+	config_group_init_type_name(&sp->group, name, &space_type);
+	config_group_init_type_name(&nds->ns_group, "nodes", &nodes_type);
+
+	sp->group.default_groups = gps;
+	sp->group.default_groups[0] = &nds->ns_group;
+	sp->group.default_groups[1] = NULL;
+
+	INIT_LIST_HEAD(&sp->members);
+	init_MUTEX(&sp->members_lock);
+	sp->members_count = 0;
+	return &sp->group;
+
+ fail:
+	kfree(sp);
+	kfree(gps);
+	kfree(nds);
+	return NULL;
+}
+
+static void drop_space(struct config_group *g, struct config_item *i)
+{
+	struct space *sp = to_space(i);
+	struct config_item *tmp;
+	int j;
+
+	/* assert list_empty(&sp->members) */
+
+	for (j = 0; sp->group.default_groups[j]; j++) {
+		tmp = &sp->group.default_groups[j]->cg_item;
+		sp->group.default_groups[j] = NULL;
+		config_item_put(tmp);
+	}
+
+	config_item_put(i);
+}
+
+static void release_space(struct config_item *i)
+{
+	struct space *sp = to_space(i);
+	kfree(sp->group.default_groups);
+	kfree(sp);
+}
+
+static struct config_item *make_comm(struct config_group *g, const char *name)
+{
+	struct comm *cm;
+
+	cm = kzalloc(sizeof(struct comm), GFP_KERNEL);
+	if (!cm)
+		return NULL;
+
+	config_item_init_type_name(&cm->item, name, &comm_type);
+	cm->nodeid = -1;
+	cm->local = 0;
+	cm->addr_count = 0;
+	return &cm->item;
+}
+
+static void drop_comm(struct config_group *g, struct config_item *i)
+{
+	struct comm *cm = to_comm(i);
+	if (local_comm == cm)
+		local_comm = NULL;
+	while (cm->addr_count--)
+		kfree(cm->addr[cm->addr_count]);
+	config_item_put(i);
+}
+
+static void release_comm(struct config_item *i)
+{
+	struct comm *cm = to_comm(i);
+	kfree(cm);
+}
+
+static struct config_item *make_node(struct config_group *g, const char *name)
+{
+	struct space *sp = to_space(g->cg_item.ci_parent);
+	struct node *nd;
+
+	nd = kzalloc(sizeof(struct node), GFP_KERNEL);
+	if (!nd)
+		return NULL;
+
+	config_item_init_type_name(&nd->item, name, &node_type);
+	nd->nodeid = -1;
+	nd->weight = 1;  /* default weight of 1 if none is set */
+
+	down(&sp->members_lock);
+	list_add(&nd->list, &sp->members);
+	sp->members_count++;
+	up(&sp->members_lock);
+
+	return &nd->item;
+}
+
+static void drop_node(struct config_group *g, struct config_item *i)
+{
+	struct space *sp = to_space(g->cg_item.ci_parent);
+	struct node *nd = to_node(i);
+
+	down(&sp->members_lock);
+	list_del(&nd->list);
+	sp->members_count--;
+	up(&sp->members_lock);
+
+	config_item_put(i);
+}
+
+static void release_node(struct config_item *i)
+{
+	struct node *nd = to_node(i);
+	kfree(nd);
+}
+
+static struct clusters clusters_root = {
+	.subsys = {
+		.su_group = {
+			.cg_item = {
+				.ci_namebuf = "dlm",
+				.ci_type = &clusters_type,
+			},
+		},
+	},
+};
+
+int dlm_config_init(void)
+{
+	config_group_init(&clusters_root.subsys.su_group);
+	init_MUTEX(&clusters_root.subsys.su_sem);
+	return configfs_register_subsystem(&clusters_root.subsys);
+}
+
+void dlm_config_exit(void)
+{
+	configfs_unregister_subsystem(&clusters_root.subsys);
+}
+
+/*
+ * Functions for user space to read/write attributes
+ */
+
+static ssize_t show_comm(struct config_item *i, struct configfs_attribute *a,
+			 char *buf)
+{
+	struct comm *cm = to_comm(i);
+	struct comm_attribute *cma =
+			container_of(a, struct comm_attribute, attr);
+	return cma->show ? cma->show(cm, buf) : 0;
+}
+
+static ssize_t store_comm(struct config_item *i, struct configfs_attribute *a,
+			  const char *buf, size_t len)
+{
+	struct comm *cm = to_comm(i);
+	struct comm_attribute *cma =
+		container_of(a, struct comm_attribute, attr);
+	return cma->store ? cma->store(cm, buf, len) : -EINVAL;
+}
+
+static ssize_t comm_nodeid_read(struct comm *cm, char *buf)
+{
+	return sprintf(buf, "%d\n", cm->nodeid);
+}
+
+static ssize_t comm_nodeid_write(struct comm *cm, const char *buf, size_t len)
+{
+	cm->nodeid = simple_strtol(buf, NULL, 0);
+	return len;
+}
+
+static ssize_t comm_local_read(struct comm *cm, char *buf)
+{
+	return sprintf(buf, "%d\n", cm->local);
+}
+
+static ssize_t comm_local_write(struct comm *cm, const char *buf, size_t len)
+{
+	cm->local= simple_strtol(buf, NULL, 0);
+	if (cm->local && !local_comm)
+		local_comm = cm;
+	return len;
+}
+
+static ssize_t comm_addr_write(struct comm *cm, const char *buf, size_t len)
+{
+	struct sockaddr_storage *addr;
+
+	if (len != sizeof(struct sockaddr_storage))
+		return -EINVAL;
+
+	if (cm->addr_count >= DLM_MAX_ADDR_COUNT)
+		return -ENOSPC;
+
+	addr = kzalloc(sizeof(*addr), GFP_KERNEL);
+	if (!addr)
+		return -ENOMEM;
+
+	memcpy(addr, buf, len);
+	cm->addr[cm->addr_count++] = addr;
+	return len;
+}
+
+static ssize_t show_node(struct config_item *i, struct configfs_attribute *a,
+			 char *buf)
+{
+	struct node *nd = to_node(i);
+	struct node_attribute *nda =
+			container_of(a, struct node_attribute, attr);
+	return nda->show ? nda->show(nd, buf) : 0;
+}
+
+static ssize_t store_node(struct config_item *i, struct configfs_attribute *a,
+			  const char *buf, size_t len)
+{
+	struct node *nd = to_node(i);
+	struct node_attribute *nda =
+		container_of(a, struct node_attribute, attr);
+	return nda->store ? nda->store(nd, buf, len) : -EINVAL;
+}
+
+static ssize_t node_nodeid_read(struct node *nd, char *buf)
+{
+	return sprintf(buf, "%d\n", nd->nodeid);
+}
+
+static ssize_t node_nodeid_write(struct node *nd, const char *buf, size_t len)
+{
+	nd->nodeid = simple_strtol(buf, NULL, 0);
+	return len;
+}
+
+static ssize_t node_weight_read(struct node *nd, char *buf)
+{
+	return sprintf(buf, "%d\n", nd->weight);
+}
+
+static ssize_t node_weight_write(struct node *nd, const char *buf, size_t len)
+{
+	nd->weight = simple_strtol(buf, NULL, 0);
+	return len;
+}
+
+/*
+ * Functions for the dlm to get the info that's been configured
+ */
+
+static struct space *get_space(char *name)
+{
+	if (!space_list)
+		return NULL;
+	return to_space(config_group_find_obj(space_list, name));
+}
+
+static void put_space(struct space *sp)
+{
+	config_item_put(&sp->group.cg_item);
+}
+
+static struct comm *get_comm(int nodeid, struct sockaddr_storage *addr)
+{
+	struct config_item *i;
+	struct comm *cm = NULL;
+	int found = 0;
+
+	if (!comm_list)
+		return NULL;
+
+	down(&clusters_root.subsys.su_sem);
+
+	list_for_each_entry(i, &comm_list->cg_children, ci_entry) {
+		cm = to_comm(i);
+
+		if (nodeid) {
+			if (cm->nodeid != nodeid)
+				continue;
+			found = 1;
+			break;
+		} else {
+			if (!cm->addr_count ||
+			    memcmp(cm->addr[0], addr, sizeof(*addr)))
+				continue;
+			found = 1;
+			break;
+		}
+	}
+	up(&clusters_root.subsys.su_sem);
+
+	if (found)
+		config_item_get(i);
+	else
+		cm = NULL;
+	return cm;
+}
+
+static void put_comm(struct comm *cm)
+{
+	config_item_put(&cm->item);
+}
+
+/* caller must free mem */
+int dlm_nodeid_list(char *lsname, int **ids_out)
+{
+	struct space *sp;
+	struct node *nd;
+	int i = 0, rv = 0;
+	int *ids;
+
+	sp = get_space(lsname);
+	if (!sp)
+		return -EEXIST;
+
+	down(&sp->members_lock);
+	if (!sp->members_count) {
+		rv = 0;
+		goto out;
+	}
+
+	ids = kcalloc(sp->members_count, sizeof(int), GFP_KERNEL);
+	if (!ids) {
+		rv = -ENOMEM;
+		goto out;
+	}
+
+	rv = sp->members_count;
+	list_for_each_entry(nd, &sp->members, list)
+		ids[i++] = nd->nodeid;
+
+	if (rv != i)
+		printk("bad nodeid count %d %d\n", rv, i);
+
+	*ids_out = ids;
+ out:
+	up(&sp->members_lock);
+	put_space(sp);
+	return rv;
+}
+
+int dlm_node_weight(char *lsname, int nodeid)
+{
+	struct space *sp;
+	struct node *nd;
+	int w = -EEXIST;
+
+	sp = get_space(lsname);
+	if (!sp)
+		goto out;
+
+	down(&sp->members_lock);
+	list_for_each_entry(nd, &sp->members, list) {
+		if (nd->nodeid != nodeid)
+			continue;
+		w = nd->weight;
+		break;
+	}
+	up(&sp->members_lock);
+	put_space(sp);
+ out:
+	return w;
+}
+
+int dlm_nodeid_to_addr(int nodeid, struct sockaddr_storage *addr)
+{
+	struct comm *cm = get_comm(nodeid, NULL);
+	if (!cm)
+		return -EEXIST;
+	if (!cm->addr_count)
+		return -ENOENT;
+	memcpy(addr, cm->addr[0], sizeof(*addr));
+	put_comm(cm);
+	return 0;
+}
+
+int dlm_addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid)
+{
+	struct comm *cm = get_comm(0, addr);
+	if (!cm)
+		return -EEXIST;
+	*nodeid = cm->nodeid;
+	put_comm(cm);
+	return 0;
+}
+
+int dlm_our_nodeid(void)
+{
+	return local_comm ? local_comm->nodeid : 0;
+}
+
+/* num 0 is first addr, num 1 is second addr */
+int dlm_our_addr(struct sockaddr_storage *addr, int num)
+{
+	if (!local_comm)
+		return -1;
+	if (num + 1 > local_comm->addr_count)
+		return -1;
+	memcpy(addr, local_comm->addr[num], sizeof(*addr));
+	return 0;
+}
+
+/* Config file defaults */
+#define DEFAULT_TCP_PORT       21064
+#define DEFAULT_BUFFER_SIZE     4096
+#define DEFAULT_RSBTBL_SIZE      256
+#define DEFAULT_LKBTBL_SIZE     1024
+#define DEFAULT_DIRTBL_SIZE      512
+#define DEFAULT_RECOVER_TIMER      5
+#define DEFAULT_TOSS_SECS         10
+#define DEFAULT_SCAN_SECS          5
+
+struct dlm_config_info dlm_config = {
+	.tcp_port = DEFAULT_TCP_PORT,
+	.buffer_size = DEFAULT_BUFFER_SIZE,
+	.rsbtbl_size = DEFAULT_RSBTBL_SIZE,
+	.lkbtbl_size = DEFAULT_LKBTBL_SIZE,
+	.dirtbl_size = DEFAULT_DIRTBL_SIZE,
+	.recover_timer = DEFAULT_RECOVER_TIMER,
+	.toss_secs = DEFAULT_TOSS_SECS,
+	.scan_secs = DEFAULT_SCAN_SECS
+};
+