Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 912 insertions, 0 deletions

diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
new file mode 100644
index 000000000..624617c12
--- /dev/null
+++ b/fs/dlm/lockspace.c
@@ -0,0 +1,912 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/******************************************************************************
+*******************************************************************************
+**
+**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
+**  Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
+**
+**
+*******************************************************************************
+******************************************************************************/
+
+#include <linux/module.h>
+
+#include "dlm_internal.h"
+#include "lockspace.h"
+#include "member.h"
+#include "recoverd.h"
+#include "dir.h"
+#include "lowcomms.h"
+#include "config.h"
+#include "memory.h"
+#include "lock.h"
+#include "recover.h"
+#include "requestqueue.h"
+#include "user.h"
+#include "ast.h"
+
+static int			ls_count;
+static struct mutex		ls_lock;
+static struct list_head		lslist;
+static spinlock_t		lslist_lock;
+static struct task_struct *	scand_task;
+
+
+static ssize_t dlm_control_store(struct dlm_ls *ls, const char *buf, size_t len)
+{
+	ssize_t ret = len;
+	int n;
+	int rc = kstrtoint(buf, 0, &n);
+
+	if (rc)
+		return rc;
+	ls = dlm_find_lockspace_local(ls->ls_local_handle);
+	if (!ls)
+		return -EINVAL;
+
+	switch (n) {
+	case 0:
+		dlm_ls_stop(ls);
+		break;
+	case 1:
+		dlm_ls_start(ls);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	dlm_put_lockspace(ls);
+	return ret;
+}
+
+static ssize_t dlm_event_store(struct dlm_ls *ls, const char *buf, size_t len)
+{
+	int rc = kstrtoint(buf, 0, &ls->ls_uevent_result);
+
+	if (rc)
+		return rc;
+	set_bit(LSFL_UEVENT_WAIT, &ls->ls_flags);
+	wake_up(&ls->ls_uevent_wait);
+	return len;
+}
+
+static ssize_t dlm_id_show(struct dlm_ls *ls, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%u\n", ls->ls_global_id);
+}
+
+static ssize_t dlm_id_store(struct dlm_ls *ls, const char *buf, size_t len)
+{
+	int rc = kstrtouint(buf, 0, &ls->ls_global_id);
+
+	if (rc)
+		return rc;
+	return len;
+}
+
+static ssize_t dlm_nodir_show(struct dlm_ls *ls, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%u\n", dlm_no_directory(ls));
+}
+
+static ssize_t dlm_nodir_store(struct dlm_ls *ls, const char *buf, size_t len)
+{
+	int val;
+	int rc = kstrtoint(buf, 0, &val);
+
+	if (rc)
+		return rc;
+	if (val == 1)
+		set_bit(LSFL_NODIR, &ls->ls_flags);
+	return len;
+}
+
+static ssize_t dlm_recover_status_show(struct dlm_ls *ls, char *buf)
+{
+	uint32_t status = dlm_recover_status(ls);
+	return snprintf(buf, PAGE_SIZE, "%x\n", status);
+}
+
+static ssize_t dlm_recover_nodeid_show(struct dlm_ls *ls, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%d\n", ls->ls_recover_nodeid);
+}
+
+struct dlm_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct dlm_ls *, char *);
+	ssize_t (*store)(struct dlm_ls *, const char *, size_t);
+};
+
+static struct dlm_attr dlm_attr_control = {
+	.attr  = {.name = "control", .mode = S_IWUSR},
+	.store = dlm_control_store
+};
+
+static struct dlm_attr dlm_attr_event = {
+	.attr  = {.name = "event_done", .mode = S_IWUSR},
+	.store = dlm_event_store
+};
+
+static struct dlm_attr dlm_attr_id = {
+	.attr  = {.name = "id", .mode = S_IRUGO | S_IWUSR},
+	.show  = dlm_id_show,
+	.store = dlm_id_store
+};
+
+static struct dlm_attr dlm_attr_nodir = {
+	.attr  = {.name = "nodir", .mode = S_IRUGO | S_IWUSR},
+	.show  = dlm_nodir_show,
+	.store = dlm_nodir_store
+};
+
+static struct dlm_attr dlm_attr_recover_status = {
+	.attr  = {.name = "recover_status", .mode = S_IRUGO},
+	.show  = dlm_recover_status_show
+};
+
+static struct dlm_attr dlm_attr_recover_nodeid = {
+	.attr  = {.name = "recover_nodeid", .mode = S_IRUGO},
+	.show  = dlm_recover_nodeid_show
+};
+
+static struct attribute *dlm_attrs[] = {
+	&dlm_attr_control.attr,
+	&dlm_attr_event.attr,
+	&dlm_attr_id.attr,
+	&dlm_attr_nodir.attr,
+	&dlm_attr_recover_status.attr,
+	&dlm_attr_recover_nodeid.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(dlm);
+
+static ssize_t dlm_attr_show(struct kobject *kobj, struct attribute *attr,
+			     char *buf)
+{
+	struct dlm_ls *ls  = container_of(kobj, struct dlm_ls, ls_kobj);
+	struct dlm_attr *a = container_of(attr, struct dlm_attr, attr);
+	return a->show ? a->show(ls, buf) : 0;
+}
+
+static ssize_t dlm_attr_store(struct kobject *kobj, struct attribute *attr,
+			      const char *buf, size_t len)
+{
+	struct dlm_ls *ls  = container_of(kobj, struct dlm_ls, ls_kobj);
+	struct dlm_attr *a = container_of(attr, struct dlm_attr, attr);
+	return a->store ? a->store(ls, buf, len) : len;
+}
+
+static void lockspace_kobj_release(struct kobject *k)
+{
+	struct dlm_ls *ls  = container_of(k, struct dlm_ls, ls_kobj);
+	kfree(ls);
+}
+
+static const struct sysfs_ops dlm_attr_ops = {
+	.show  = dlm_attr_show,
+	.store = dlm_attr_store,
+};
+
+static struct kobj_type dlm_ktype = {
+	.default_groups = dlm_groups,
+	.sysfs_ops     = &dlm_attr_ops,
+	.release       = lockspace_kobj_release,
+};
+
+static struct kset *dlm_kset;
+
+static int do_uevent(struct dlm_ls *ls, int in)
+{
+	if (in)
+		kobject_uevent(&ls->ls_kobj, KOBJ_ONLINE);
+	else
+		kobject_uevent(&ls->ls_kobj, KOBJ_OFFLINE);
+
+	log_rinfo(ls, "%s the lockspace group...", in ? "joining" : "leaving");
+
+	/* dlm_controld will see the uevent, do the necessary group management
+	   and then write to sysfs to wake us */
+
+	wait_event(ls->ls_uevent_wait,
+		   test_and_clear_bit(LSFL_UEVENT_WAIT, &ls->ls_flags));
+
+	log_rinfo(ls, "group event done %d", ls->ls_uevent_result);
+
+	return ls->ls_uevent_result;
+}
+
+static int dlm_uevent(struct kset *kset, struct kobject *kobj,
+		      struct kobj_uevent_env *env)
+{
+	struct dlm_ls *ls = container_of(kobj, struct dlm_ls, ls_kobj);
+
+	add_uevent_var(env, "LOCKSPACE=%s", ls->ls_name);
+	return 0;
+}
+
+static const struct kset_uevent_ops dlm_uevent_ops = {
+	.uevent = dlm_uevent,
+};
+
+int __init dlm_lockspace_init(void)
+{
+	ls_count = 0;
+	mutex_init(&ls_lock);
+	INIT_LIST_HEAD(&lslist);
+	spin_lock_init(&lslist_lock);
+
+	dlm_kset = kset_create_and_add("dlm", &dlm_uevent_ops, kernel_kobj);
+	if (!dlm_kset) {
+		printk(KERN_WARNING "%s: can not create kset\n", __func__);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void dlm_lockspace_exit(void)
+{
+	kset_unregister(dlm_kset);
+}
+
+static struct dlm_ls *find_ls_to_scan(void)
+{
+	struct dlm_ls *ls;
+
+	spin_lock(&lslist_lock);
+	list_for_each_entry(ls, &lslist, ls_list) {
+		if (time_after_eq(jiffies, ls->ls_scan_time +
+					    dlm_config.ci_scan_secs * HZ)) {
+			spin_unlock(&lslist_lock);
+			return ls;
+		}
+	}
+	spin_unlock(&lslist_lock);
+	return NULL;
+}
+
+static int dlm_scand(void *data)
+{
+	struct dlm_ls *ls;
+
+	while (!kthread_should_stop()) {
+		ls = find_ls_to_scan();
+		if (ls) {
+			if (dlm_lock_recovery_try(ls)) {
+				ls->ls_scan_time = jiffies;
+				dlm_scan_rsbs(ls);
+				dlm_scan_timeout(ls);
+				dlm_scan_waiters(ls);
+				dlm_unlock_recovery(ls);
+			} else {
+				ls->ls_scan_time += HZ;
+			}
+			continue;
+		}
+		schedule_timeout_interruptible(dlm_config.ci_scan_secs * HZ);
+	}
+	return 0;
+}
+
+static int dlm_scand_start(void)
+{
+	struct task_struct *p;
+	int error = 0;
+
+	p = kthread_run(dlm_scand, NULL, "dlm_scand");
+	if (IS_ERR(p))
+		error = PTR_ERR(p);
+	else
+		scand_task = p;
+	return error;
+}
+
+static void dlm_scand_stop(void)
+{
+	kthread_stop(scand_task);
+}
+
+struct dlm_ls *dlm_find_lockspace_global(uint32_t id)
+{
+	struct dlm_ls *ls;
+
+	spin_lock(&lslist_lock);
+
+	list_for_each_entry(ls, &lslist, ls_list) {
+		if (ls->ls_global_id == id) {
+			ls->ls_count++;
+			goto out;
+		}
+	}
+	ls = NULL;
+ out:
+	spin_unlock(&lslist_lock);
+	return ls;
+}
+
+struct dlm_ls *dlm_find_lockspace_local(dlm_lockspace_t *lockspace)
+{
+	struct dlm_ls *ls;
+
+	spin_lock(&lslist_lock);
+	list_for_each_entry(ls, &lslist, ls_list) {
+		if (ls->ls_local_handle == lockspace) {
+			ls->ls_count++;
+			goto out;
+		}
+	}
+	ls = NULL;
+ out:
+	spin_unlock(&lslist_lock);
+	return ls;
+}
+
+struct dlm_ls *dlm_find_lockspace_device(int minor)
+{
+	struct dlm_ls *ls;
+
+	spin_lock(&lslist_lock);
+	list_for_each_entry(ls, &lslist, ls_list) {
+		if (ls->ls_device.minor == minor) {
+			ls->ls_count++;
+			goto out;
+		}
+	}
+	ls = NULL;
+ out:
+	spin_unlock(&lslist_lock);
+	return ls;
+}
+
+void dlm_put_lockspace(struct dlm_ls *ls)
+{
+	spin_lock(&lslist_lock);
+	ls->ls_count--;
+	spin_unlock(&lslist_lock);
+}
+
+static void remove_lockspace(struct dlm_ls *ls)
+{
+	for (;;) {
+		spin_lock(&lslist_lock);
+		if (ls->ls_count == 0) {
+			WARN_ON(ls->ls_create_count != 0);
+			list_del(&ls->ls_list);
+			spin_unlock(&lslist_lock);
+			return;
+		}
+		spin_unlock(&lslist_lock);
+		ssleep(1);
+	}
+}
+
+static int threads_start(void)
+{
+	int error;
+
+	error = dlm_scand_start();
+	if (error) {
+		log_print("cannot start dlm_scand thread %d", error);
+		goto fail;
+	}
+
+	/* Thread for sending/receiving messages for all lockspace's */
+	error = dlm_lowcomms_start();
+	if (error) {
+		log_print("cannot start dlm lowcomms %d", error);
+		goto scand_fail;
+	}
+
+	return 0;
+
+ scand_fail:
+	dlm_scand_stop();
+ fail:
+	return error;
+}
+
+static void threads_stop(void)
+{
+	dlm_scand_stop();
+	dlm_lowcomms_stop();
+}
+
+static int new_lockspace(const char *name, const char *cluster,
+			 uint32_t flags, int lvblen,
+			 const struct dlm_lockspace_ops *ops, void *ops_arg,
+			 int *ops_result, dlm_lockspace_t **lockspace)
+{
+	struct dlm_ls *ls;
+	int i, size, error;
+	int do_unreg = 0;
+	int namelen = strlen(name);
+
+	if (namelen > DLM_LOCKSPACE_LEN || namelen == 0)
+		return -EINVAL;
+
+	if (!lvblen || (lvblen % 8))
+		return -EINVAL;
+
+	if (!try_module_get(THIS_MODULE))
+		return -EINVAL;
+
+	if (!dlm_user_daemon_available()) {
+		log_print("dlm user daemon not available");
+		error = -EUNATCH;
+		goto out;
+	}
+
+	if (ops && ops_result) {
+	       	if (!dlm_config.ci_recover_callbacks)
+			*ops_result = -EOPNOTSUPP;
+		else
+			*ops_result = 0;
+	}
+
+	if (!cluster)
+		log_print("dlm cluster name '%s' is being used without an application provided cluster name",
+			  dlm_config.ci_cluster_name);
+
+	if (dlm_config.ci_recover_callbacks && cluster &&
+	    strncmp(cluster, dlm_config.ci_cluster_name, DLM_LOCKSPACE_LEN)) {
+		log_print("dlm cluster name '%s' does not match "
+			  "the application cluster name '%s'",
+			  dlm_config.ci_cluster_name, cluster);
+		error = -EBADR;
+		goto out;
+	}
+
+	error = 0;
+
+	spin_lock(&lslist_lock);
+	list_for_each_entry(ls, &lslist, ls_list) {
+		WARN_ON(ls->ls_create_count <= 0);
+		if (ls->ls_namelen != namelen)
+			continue;
+		if (memcmp(ls->ls_name, name, namelen))
+			continue;
+		if (flags & DLM_LSFL_NEWEXCL) {
+			error = -EEXIST;
+			break;
+		}
+		ls->ls_create_count++;
+		*lockspace = ls;
+		error = 1;
+		break;
+	}
+	spin_unlock(&lslist_lock);
+
+	if (error)
+		goto out;
+
+	error = -ENOMEM;
+
+	ls = kzalloc(sizeof(struct dlm_ls) + namelen, GFP_NOFS);
+	if (!ls)
+		goto out;
+	memcpy(ls->ls_name, name, namelen);
+	ls->ls_namelen = namelen;
+	ls->ls_lvblen = lvblen;
+	ls->ls_count = 0;
+	ls->ls_flags = 0;
+	ls->ls_scan_time = jiffies;
+
+	if (ops && dlm_config.ci_recover_callbacks) {
+		ls->ls_ops = ops;
+		ls->ls_ops_arg = ops_arg;
+	}
+
+	if (flags & DLM_LSFL_TIMEWARN)
+		set_bit(LSFL_TIMEWARN, &ls->ls_flags);
+
+	/* ls_exflags are forced to match among nodes, and we don't
+	   need to require all nodes to have some flags set */
+	ls->ls_exflags = (flags & ~(DLM_LSFL_TIMEWARN | DLM_LSFL_FS |
+				    DLM_LSFL_NEWEXCL));
+
+	size = dlm_config.ci_rsbtbl_size;
+	ls->ls_rsbtbl_size = size;
+
+	ls->ls_rsbtbl = vmalloc(array_size(size, sizeof(struct dlm_rsbtable)));
+	if (!ls->ls_rsbtbl)
+		goto out_lsfree;
+	for (i = 0; i < size; i++) {
+		ls->ls_rsbtbl[i].keep.rb_node = NULL;
+		ls->ls_rsbtbl[i].toss.rb_node = NULL;
+		spin_lock_init(&ls->ls_rsbtbl[i].lock);
+	}
+
+	spin_lock_init(&ls->ls_remove_spin);
+
+	for (i = 0; i < DLM_REMOVE_NAMES_MAX; i++) {
+		ls->ls_remove_names[i] = kzalloc(DLM_RESNAME_MAXLEN+1,
+						 GFP_KERNEL);
+		if (!ls->ls_remove_names[i])
+			goto out_rsbtbl;
+	}
+
+	idr_init(&ls->ls_lkbidr);
+	spin_lock_init(&ls->ls_lkbidr_spin);
+
+	INIT_LIST_HEAD(&ls->ls_waiters);
+	mutex_init(&ls->ls_waiters_mutex);
+	INIT_LIST_HEAD(&ls->ls_orphans);
+	mutex_init(&ls->ls_orphans_mutex);
+	INIT_LIST_HEAD(&ls->ls_timeout);
+	mutex_init(&ls->ls_timeout_mutex);
+
+	INIT_LIST_HEAD(&ls->ls_new_rsb);
+	spin_lock_init(&ls->ls_new_rsb_spin);
+
+	INIT_LIST_HEAD(&ls->ls_nodes);
+	INIT_LIST_HEAD(&ls->ls_nodes_gone);
+	ls->ls_num_nodes = 0;
+	ls->ls_low_nodeid = 0;
+	ls->ls_total_weight = 0;
+	ls->ls_node_array = NULL;
+
+	memset(&ls->ls_stub_rsb, 0, sizeof(struct dlm_rsb));
+	ls->ls_stub_rsb.res_ls = ls;
+
+	ls->ls_debug_rsb_dentry = NULL;
+	ls->ls_debug_waiters_dentry = NULL;
+
+	init_waitqueue_head(&ls->ls_uevent_wait);
+	ls->ls_uevent_result = 0;
+	init_completion(&ls->ls_members_done);
+	ls->ls_members_result = -1;
+
+	mutex_init(&ls->ls_cb_mutex);
+	INIT_LIST_HEAD(&ls->ls_cb_delay);
+
+	ls->ls_recoverd_task = NULL;
+	mutex_init(&ls->ls_recoverd_active);
+	spin_lock_init(&ls->ls_recover_lock);
+	spin_lock_init(&ls->ls_rcom_spin);
+	get_random_bytes(&ls->ls_rcom_seq, sizeof(uint64_t));
+	ls->ls_recover_status = 0;
+	ls->ls_recover_seq = 0;
+	ls->ls_recover_args = NULL;
+	init_rwsem(&ls->ls_in_recovery);
+	init_rwsem(&ls->ls_recv_active);
+	INIT_LIST_HEAD(&ls->ls_requestqueue);
+	mutex_init(&ls->ls_requestqueue_mutex);
+	mutex_init(&ls->ls_clear_proc_locks);
+
+	ls->ls_recover_buf = kmalloc(dlm_config.ci_buffer_size, GFP_NOFS);
+	if (!ls->ls_recover_buf)
+		goto out_lkbidr;
+
+	ls->ls_slot = 0;
+	ls->ls_num_slots = 0;
+	ls->ls_slots_size = 0;
+	ls->ls_slots = NULL;
+
+	INIT_LIST_HEAD(&ls->ls_recover_list);
+	spin_lock_init(&ls->ls_recover_list_lock);
+	idr_init(&ls->ls_recover_idr);
+	spin_lock_init(&ls->ls_recover_idr_lock);
+	ls->ls_recover_list_count = 0;
+	ls->ls_local_handle = ls;
+	init_waitqueue_head(&ls->ls_wait_general);
+	INIT_LIST_HEAD(&ls->ls_root_list);
+	init_rwsem(&ls->ls_root_sem);
+
+	spin_lock(&lslist_lock);
+	ls->ls_create_count = 1;
+	list_add(&ls->ls_list, &lslist);
+	spin_unlock(&lslist_lock);
+
+	if (flags & DLM_LSFL_FS) {
+		error = dlm_callback_start(ls);
+		if (error) {
+			log_error(ls, "can't start dlm_callback %d", error);
+			goto out_delist;
+		}
+	}
+
+	init_waitqueue_head(&ls->ls_recover_lock_wait);
+
+	/*
+	 * Once started, dlm_recoverd first looks for ls in lslist, then
+	 * initializes ls_in_recovery as locked in "down" mode.  We need
+	 * to wait for the wakeup from dlm_recoverd because in_recovery
+	 * has to start out in down mode.
+	 */
+
+	error = dlm_recoverd_start(ls);
+	if (error) {
+		log_error(ls, "can't start dlm_recoverd %d", error);
+		goto out_callback;
+	}
+
+	wait_event(ls->ls_recover_lock_wait,
+		   test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags));
+
+	/* let kobject handle freeing of ls if there's an error */
+	do_unreg = 1;
+
+	ls->ls_kobj.kset = dlm_kset;
+	error = kobject_init_and_add(&ls->ls_kobj, &dlm_ktype, NULL,
+				     "%s", ls->ls_name);
+	if (error)
+		goto out_recoverd;
+	kobject_uevent(&ls->ls_kobj, KOBJ_ADD);
+
+	/* This uevent triggers dlm_controld in userspace to add us to the
+	   group of nodes that are members of this lockspace (managed by the
+	   cluster infrastructure.)  Once it's done that, it tells us who the
+	   current lockspace members are (via configfs) and then tells the
+	   lockspace to start running (via sysfs) in dlm_ls_start(). */
+
+	error = do_uevent(ls, 1);
+	if (error)
+		goto out_recoverd;
+
+	wait_for_completion(&ls->ls_members_done);
+	error = ls->ls_members_result;
+	if (error)
+		goto out_members;
+
+	dlm_create_debug_file(ls);
+
+	log_rinfo(ls, "join complete");
+	*lockspace = ls;
+	return 0;
+
+ out_members:
+	do_uevent(ls, 0);
+	dlm_clear_members(ls);
+	kfree(ls->ls_node_array);
+ out_recoverd:
+	dlm_recoverd_stop(ls);
+ out_callback:
+	dlm_callback_stop(ls);
+ out_delist:
+	spin_lock(&lslist_lock);
+	list_del(&ls->ls_list);
+	spin_unlock(&lslist_lock);
+	idr_destroy(&ls->ls_recover_idr);
+	kfree(ls->ls_recover_buf);
+ out_lkbidr:
+	idr_destroy(&ls->ls_lkbidr);
+ out_rsbtbl:
+	for (i = 0; i < DLM_REMOVE_NAMES_MAX; i++)
+		kfree(ls->ls_remove_names[i]);
+	vfree(ls->ls_rsbtbl);
+ out_lsfree:
+	if (do_unreg)
+		kobject_put(&ls->ls_kobj);
+	else
+		kfree(ls);
+ out:
+	module_put(THIS_MODULE);
+	return error;
+}
+
+int dlm_new_lockspace(const char *name, const char *cluster,
+		      uint32_t flags, int lvblen,
+		      const struct dlm_lockspace_ops *ops, void *ops_arg,
+		      int *ops_result, dlm_lockspace_t **lockspace)
+{
+	int error = 0;
+
+	mutex_lock(&ls_lock);
+	if (!ls_count)
+		error = threads_start();
+	if (error)
+		goto out;
+
+	error = new_lockspace(name, cluster, flags, lvblen, ops, ops_arg,
+			      ops_result, lockspace);
+	if (!error)
+		ls_count++;
+	if (error > 0)
+		error = 0;
+	if (!ls_count)
+		threads_stop();
+ out:
+	mutex_unlock(&ls_lock);
+	return error;
+}
+
+static int lkb_idr_is_local(int id, void *p, void *data)
+{
+	struct dlm_lkb *lkb = p;
+
+	return lkb->lkb_nodeid == 0 && lkb->lkb_grmode != DLM_LOCK_IV;
+}
+
+static int lkb_idr_is_any(int id, void *p, void *data)
+{
+	return 1;
+}
+
+static int lkb_idr_free(int id, void *p, void *data)
+{
+	struct dlm_lkb *lkb = p;
+
+	if (lkb->lkb_lvbptr && lkb->lkb_flags & DLM_IFL_MSTCPY)
+		dlm_free_lvb(lkb->lkb_lvbptr);
+
+	dlm_free_lkb(lkb);
+	return 0;
+}
+
+/* NOTE: We check the lkbidr here rather than the resource table.
+   This is because there may be LKBs queued as ASTs that have been unlinked
+   from their RSBs and are pending deletion once the AST has been delivered */
+
+static int lockspace_busy(struct dlm_ls *ls, int force)
+{
+	int rv;
+
+	spin_lock(&ls->ls_lkbidr_spin);
+	if (force == 0) {
+		rv = idr_for_each(&ls->ls_lkbidr, lkb_idr_is_any, ls);
+	} else if (force == 1) {
+		rv = idr_for_each(&ls->ls_lkbidr, lkb_idr_is_local, ls);
+	} else {
+		rv = 0;
+	}
+	spin_unlock(&ls->ls_lkbidr_spin);
+	return rv;
+}
+
+static int release_lockspace(struct dlm_ls *ls, int force)
+{
+	struct dlm_rsb *rsb;
+	struct rb_node *n;
+	int i, busy, rv;
+
+	busy = lockspace_busy(ls, force);
+
+	spin_lock(&lslist_lock);
+	if (ls->ls_create_count == 1) {
+		if (busy) {
+			rv = -EBUSY;
+		} else {
+			/* remove_lockspace takes ls off lslist */
+			ls->ls_create_count = 0;
+			rv = 0;
+		}
+	} else if (ls->ls_create_count > 1) {
+		rv = --ls->ls_create_count;
+	} else {
+		rv = -EINVAL;
+	}
+	spin_unlock(&lslist_lock);
+
+	if (rv) {
+		log_debug(ls, "release_lockspace no remove %d", rv);
+		return rv;
+	}
+
+	dlm_device_deregister(ls);
+
+	if (force < 3 && dlm_user_daemon_available())
+		do_uevent(ls, 0);
+
+	dlm_recoverd_stop(ls);
+
+	dlm_callback_stop(ls);
+
+	remove_lockspace(ls);
+
+	dlm_delete_debug_file(ls);
+
+	idr_destroy(&ls->ls_recover_idr);
+	kfree(ls->ls_recover_buf);
+
+	/*
+	 * Free all lkb's in idr
+	 */
+
+	idr_for_each(&ls->ls_lkbidr, lkb_idr_free, ls);
+	idr_destroy(&ls->ls_lkbidr);
+
+	/*
+	 * Free all rsb's on rsbtbl[] lists
+	 */
+
+	for (i = 0; i < ls->ls_rsbtbl_size; i++) {
+		while ((n = rb_first(&ls->ls_rsbtbl[i].keep))) {
+			rsb = rb_entry(n, struct dlm_rsb, res_hashnode);
+			rb_erase(n, &ls->ls_rsbtbl[i].keep);
+			dlm_free_rsb(rsb);
+		}
+
+		while ((n = rb_first(&ls->ls_rsbtbl[i].toss))) {
+			rsb = rb_entry(n, struct dlm_rsb, res_hashnode);
+			rb_erase(n, &ls->ls_rsbtbl[i].toss);
+			dlm_free_rsb(rsb);
+		}
+	}
+
+	vfree(ls->ls_rsbtbl);
+
+	for (i = 0; i < DLM_REMOVE_NAMES_MAX; i++)
+		kfree(ls->ls_remove_names[i]);
+
+	while (!list_empty(&ls->ls_new_rsb)) {
+		rsb = list_first_entry(&ls->ls_new_rsb, struct dlm_rsb,
+				       res_hashchain);
+		list_del(&rsb->res_hashchain);
+		dlm_free_rsb(rsb);
+	}
+
+	/*
+	 * Free structures on any other lists
+	 */
+
+	dlm_purge_requestqueue(ls);
+	kfree(ls->ls_recover_args);
+	dlm_clear_members(ls);
+	dlm_clear_members_gone(ls);
+	kfree(ls->ls_node_array);
+	log_rinfo(ls, "release_lockspace final free");
+	kobject_put(&ls->ls_kobj);
+	/* The ls structure will be freed when the kobject is done with */
+
+	module_put(THIS_MODULE);
+	return 0;
+}
+
+/*
+ * Called when a system has released all its locks and is not going to use the
+ * lockspace any longer.  We free everything we're managing for this lockspace.
+ * Remaining nodes will go through the recovery process as if we'd died.  The
+ * lockspace must continue to function as usual, participating in recoveries,
+ * until this returns.
+ *
+ * Force has 4 possible values:
+ * 0 - don't destroy locksapce if it has any LKBs
+ * 1 - destroy lockspace if it has remote LKBs but not if it has local LKBs
+ * 2 - destroy lockspace regardless of LKBs
+ * 3 - destroy lockspace as part of a forced shutdown
+ */
+
+int dlm_release_lockspace(void *lockspace, int force)
+{
+	struct dlm_ls *ls;
+	int error;
+
+	ls = dlm_find_lockspace_local(lockspace);
+	if (!ls)
+		return -EINVAL;
+	dlm_put_lockspace(ls);
+
+	mutex_lock(&ls_lock);
+	error = release_lockspace(ls, force);
+	if (!error)
+		ls_count--;
+	if (!ls_count)
+		threads_stop();
+	mutex_unlock(&ls_lock);
+
+	return error;
+}
+
+void dlm_stop_lockspaces(void)
+{
+	struct dlm_ls *ls;
+	int count;
+
+ restart:
+	count = 0;
+	spin_lock(&lslist_lock);
+	list_for_each_entry(ls, &lslist, ls_list) {
+		if (!test_bit(LSFL_RUNNING, &ls->ls_flags)) {
+			count++;
+			continue;
+		}
+		spin_unlock(&lslist_lock);
+		log_error(ls, "no userland control daemon, stopping lockspace");
+		dlm_ls_stop(ls);
+		goto restart;
+	}
+	spin_unlock(&lslist_lock);
+
+	if (count)
+		log_print("dlm user daemon left %d lockspaces", count);
+}
+