[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 000000000000..024ace9973a8
--- /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
+};
+