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-rw-r--r--fs/ocfs2/stackglue.c703
1 files changed, 703 insertions, 0 deletions
diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c
new file mode 100644
index 000000000..a8d5ca98f
--- /dev/null
+++ b/fs/ocfs2/stackglue.c
@@ -0,0 +1,703 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * stackglue.c
+ *
+ * Code which implements an OCFS2 specific interface to underlying
+ * cluster stacks.
+ *
+ * Copyright (C) 2007, 2009 Oracle. All rights reserved.
+ */
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/kmod.h>
+#include <linux/fs.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/sysctl.h>
+
+#include "ocfs2_fs.h"
+
+#include "stackglue.h"
+
+#define OCFS2_STACK_PLUGIN_O2CB "o2cb"
+#define OCFS2_STACK_PLUGIN_USER "user"
+#define OCFS2_MAX_HB_CTL_PATH 256
+
+static struct ocfs2_protocol_version locking_max_version;
+static DEFINE_SPINLOCK(ocfs2_stack_lock);
+static LIST_HEAD(ocfs2_stack_list);
+static char cluster_stack_name[OCFS2_STACK_LABEL_LEN + 1];
+static char ocfs2_hb_ctl_path[OCFS2_MAX_HB_CTL_PATH] = "/sbin/ocfs2_hb_ctl";
+
+/*
+ * The stack currently in use. If not null, active_stack->sp_count > 0,
+ * the module is pinned, and the locking protocol cannot be changed.
+ */
+static struct ocfs2_stack_plugin *active_stack;
+
+static struct ocfs2_stack_plugin *ocfs2_stack_lookup(const char *name)
+{
+ struct ocfs2_stack_plugin *p;
+
+ assert_spin_locked(&ocfs2_stack_lock);
+
+ list_for_each_entry(p, &ocfs2_stack_list, sp_list) {
+ if (!strcmp(p->sp_name, name))
+ return p;
+ }
+
+ return NULL;
+}
+
+static int ocfs2_stack_driver_request(const char *stack_name,
+ const char *plugin_name)
+{
+ int rc;
+ struct ocfs2_stack_plugin *p;
+
+ spin_lock(&ocfs2_stack_lock);
+
+ /*
+ * If the stack passed by the filesystem isn't the selected one,
+ * we can't continue.
+ */
+ if (strcmp(stack_name, cluster_stack_name)) {
+ rc = -EBUSY;
+ goto out;
+ }
+
+ if (active_stack) {
+ /*
+ * If the active stack isn't the one we want, it cannot
+ * be selected right now.
+ */
+ if (!strcmp(active_stack->sp_name, plugin_name))
+ rc = 0;
+ else
+ rc = -EBUSY;
+ goto out;
+ }
+
+ p = ocfs2_stack_lookup(plugin_name);
+ if (!p || !try_module_get(p->sp_owner)) {
+ rc = -ENOENT;
+ goto out;
+ }
+
+ active_stack = p;
+ rc = 0;
+
+out:
+ /* If we found it, pin it */
+ if (!rc)
+ active_stack->sp_count++;
+
+ spin_unlock(&ocfs2_stack_lock);
+ return rc;
+}
+
+/*
+ * This function looks up the appropriate stack and makes it active. If
+ * there is no stack, it tries to load it. It will fail if the stack still
+ * cannot be found. It will also fail if a different stack is in use.
+ */
+static int ocfs2_stack_driver_get(const char *stack_name)
+{
+ int rc;
+ char *plugin_name = OCFS2_STACK_PLUGIN_O2CB;
+
+ /*
+ * Classic stack does not pass in a stack name. This is
+ * compatible with older tools as well.
+ */
+ if (!stack_name || !*stack_name)
+ stack_name = OCFS2_STACK_PLUGIN_O2CB;
+
+ if (strlen(stack_name) != OCFS2_STACK_LABEL_LEN) {
+ printk(KERN_ERR
+ "ocfs2 passed an invalid cluster stack label: \"%s\"\n",
+ stack_name);
+ return -EINVAL;
+ }
+
+ /* Anything that isn't the classic stack is a user stack */
+ if (strcmp(stack_name, OCFS2_STACK_PLUGIN_O2CB))
+ plugin_name = OCFS2_STACK_PLUGIN_USER;
+
+ rc = ocfs2_stack_driver_request(stack_name, plugin_name);
+ if (rc == -ENOENT) {
+ request_module("ocfs2_stack_%s", plugin_name);
+ rc = ocfs2_stack_driver_request(stack_name, plugin_name);
+ }
+
+ if (rc == -ENOENT) {
+ printk(KERN_ERR
+ "ocfs2: Cluster stack driver \"%s\" cannot be found\n",
+ plugin_name);
+ } else if (rc == -EBUSY) {
+ printk(KERN_ERR
+ "ocfs2: A different cluster stack is in use\n");
+ }
+
+ return rc;
+}
+
+static void ocfs2_stack_driver_put(void)
+{
+ spin_lock(&ocfs2_stack_lock);
+ BUG_ON(active_stack == NULL);
+ BUG_ON(active_stack->sp_count == 0);
+
+ active_stack->sp_count--;
+ if (!active_stack->sp_count) {
+ module_put(active_stack->sp_owner);
+ active_stack = NULL;
+ }
+ spin_unlock(&ocfs2_stack_lock);
+}
+
+int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin)
+{
+ int rc;
+
+ spin_lock(&ocfs2_stack_lock);
+ if (!ocfs2_stack_lookup(plugin->sp_name)) {
+ plugin->sp_count = 0;
+ plugin->sp_max_proto = locking_max_version;
+ list_add(&plugin->sp_list, &ocfs2_stack_list);
+ printk(KERN_INFO "ocfs2: Registered cluster interface %s\n",
+ plugin->sp_name);
+ rc = 0;
+ } else {
+ printk(KERN_ERR "ocfs2: Stack \"%s\" already registered\n",
+ plugin->sp_name);
+ rc = -EEXIST;
+ }
+ spin_unlock(&ocfs2_stack_lock);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(ocfs2_stack_glue_register);
+
+void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin)
+{
+ struct ocfs2_stack_plugin *p;
+
+ spin_lock(&ocfs2_stack_lock);
+ p = ocfs2_stack_lookup(plugin->sp_name);
+ if (p) {
+ BUG_ON(p != plugin);
+ BUG_ON(plugin == active_stack);
+ BUG_ON(plugin->sp_count != 0);
+ list_del_init(&plugin->sp_list);
+ printk(KERN_INFO "ocfs2: Unregistered cluster interface %s\n",
+ plugin->sp_name);
+ } else {
+ printk(KERN_ERR "Stack \"%s\" is not registered\n",
+ plugin->sp_name);
+ }
+ spin_unlock(&ocfs2_stack_lock);
+}
+EXPORT_SYMBOL_GPL(ocfs2_stack_glue_unregister);
+
+void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto)
+{
+ struct ocfs2_stack_plugin *p;
+
+ spin_lock(&ocfs2_stack_lock);
+ if (memcmp(max_proto, &locking_max_version,
+ sizeof(struct ocfs2_protocol_version))) {
+ BUG_ON(locking_max_version.pv_major != 0);
+
+ locking_max_version = *max_proto;
+ list_for_each_entry(p, &ocfs2_stack_list, sp_list) {
+ p->sp_max_proto = locking_max_version;
+ }
+ }
+ spin_unlock(&ocfs2_stack_lock);
+}
+EXPORT_SYMBOL_GPL(ocfs2_stack_glue_set_max_proto_version);
+
+
+/*
+ * The ocfs2_dlm_lock() and ocfs2_dlm_unlock() functions take no argument
+ * for the ast and bast functions. They will pass the lksb to the ast
+ * and bast. The caller can wrap the lksb with their own structure to
+ * get more information.
+ */
+int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
+ int mode,
+ struct ocfs2_dlm_lksb *lksb,
+ u32 flags,
+ void *name,
+ unsigned int namelen)
+{
+ if (!lksb->lksb_conn)
+ lksb->lksb_conn = conn;
+ else
+ BUG_ON(lksb->lksb_conn != conn);
+ return active_stack->sp_ops->dlm_lock(conn, mode, lksb, flags,
+ name, namelen);
+}
+EXPORT_SYMBOL_GPL(ocfs2_dlm_lock);
+
+int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
+ struct ocfs2_dlm_lksb *lksb,
+ u32 flags)
+{
+ BUG_ON(lksb->lksb_conn == NULL);
+
+ return active_stack->sp_ops->dlm_unlock(conn, lksb, flags);
+}
+EXPORT_SYMBOL_GPL(ocfs2_dlm_unlock);
+
+int ocfs2_dlm_lock_status(struct ocfs2_dlm_lksb *lksb)
+{
+ return active_stack->sp_ops->lock_status(lksb);
+}
+EXPORT_SYMBOL_GPL(ocfs2_dlm_lock_status);
+
+int ocfs2_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb)
+{
+ return active_stack->sp_ops->lvb_valid(lksb);
+}
+EXPORT_SYMBOL_GPL(ocfs2_dlm_lvb_valid);
+
+void *ocfs2_dlm_lvb(struct ocfs2_dlm_lksb *lksb)
+{
+ return active_stack->sp_ops->lock_lvb(lksb);
+}
+EXPORT_SYMBOL_GPL(ocfs2_dlm_lvb);
+
+void ocfs2_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb)
+{
+ active_stack->sp_ops->dump_lksb(lksb);
+}
+EXPORT_SYMBOL_GPL(ocfs2_dlm_dump_lksb);
+
+int ocfs2_stack_supports_plocks(void)
+{
+ return active_stack && active_stack->sp_ops->plock;
+}
+EXPORT_SYMBOL_GPL(ocfs2_stack_supports_plocks);
+
+/*
+ * ocfs2_plock() can only be safely called if
+ * ocfs2_stack_supports_plocks() returned true
+ */
+int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino,
+ struct file *file, int cmd, struct file_lock *fl)
+{
+ WARN_ON_ONCE(active_stack->sp_ops->plock == NULL);
+ if (active_stack->sp_ops->plock)
+ return active_stack->sp_ops->plock(conn, ino, file, cmd, fl);
+ return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_GPL(ocfs2_plock);
+
+int ocfs2_cluster_connect(const char *stack_name,
+ const char *cluster_name,
+ int cluster_name_len,
+ const char *group,
+ int grouplen,
+ struct ocfs2_locking_protocol *lproto,
+ void (*recovery_handler)(int node_num,
+ void *recovery_data),
+ void *recovery_data,
+ struct ocfs2_cluster_connection **conn)
+{
+ int rc = 0;
+ struct ocfs2_cluster_connection *new_conn;
+
+ BUG_ON(group == NULL);
+ BUG_ON(conn == NULL);
+ BUG_ON(recovery_handler == NULL);
+
+ if (grouplen > GROUP_NAME_MAX) {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ if (memcmp(&lproto->lp_max_version, &locking_max_version,
+ sizeof(struct ocfs2_protocol_version))) {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ new_conn = kzalloc(sizeof(struct ocfs2_cluster_connection),
+ GFP_KERNEL);
+ if (!new_conn) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ strscpy(new_conn->cc_name, group, GROUP_NAME_MAX + 1);
+ new_conn->cc_namelen = grouplen;
+ if (cluster_name_len)
+ strscpy(new_conn->cc_cluster_name, cluster_name,
+ CLUSTER_NAME_MAX + 1);
+ new_conn->cc_cluster_name_len = cluster_name_len;
+ new_conn->cc_recovery_handler = recovery_handler;
+ new_conn->cc_recovery_data = recovery_data;
+
+ new_conn->cc_proto = lproto;
+ /* Start the new connection at our maximum compatibility level */
+ new_conn->cc_version = lproto->lp_max_version;
+
+ /* This will pin the stack driver if successful */
+ rc = ocfs2_stack_driver_get(stack_name);
+ if (rc)
+ goto out_free;
+
+ rc = active_stack->sp_ops->connect(new_conn);
+ if (rc) {
+ ocfs2_stack_driver_put();
+ goto out_free;
+ }
+
+ *conn = new_conn;
+
+out_free:
+ if (rc)
+ kfree(new_conn);
+
+out:
+ return rc;
+}
+EXPORT_SYMBOL_GPL(ocfs2_cluster_connect);
+
+/* The caller will ensure all nodes have the same cluster stack */
+int ocfs2_cluster_connect_agnostic(const char *group,
+ int grouplen,
+ struct ocfs2_locking_protocol *lproto,
+ void (*recovery_handler)(int node_num,
+ void *recovery_data),
+ void *recovery_data,
+ struct ocfs2_cluster_connection **conn)
+{
+ char *stack_name = NULL;
+
+ if (cluster_stack_name[0])
+ stack_name = cluster_stack_name;
+ return ocfs2_cluster_connect(stack_name, NULL, 0, group, grouplen,
+ lproto, recovery_handler, recovery_data,
+ conn);
+}
+EXPORT_SYMBOL_GPL(ocfs2_cluster_connect_agnostic);
+
+/* If hangup_pending is 0, the stack driver will be dropped */
+int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
+ int hangup_pending)
+{
+ int ret;
+
+ BUG_ON(conn == NULL);
+
+ ret = active_stack->sp_ops->disconnect(conn);
+
+ /* XXX Should we free it anyway? */
+ if (!ret) {
+ kfree(conn);
+ if (!hangup_pending)
+ ocfs2_stack_driver_put();
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ocfs2_cluster_disconnect);
+
+/*
+ * Leave the group for this filesystem. This is executed by a userspace
+ * program (stored in ocfs2_hb_ctl_path).
+ */
+static void ocfs2_leave_group(const char *group)
+{
+ int ret;
+ char *argv[5], *envp[3];
+
+ argv[0] = ocfs2_hb_ctl_path;
+ argv[1] = "-K";
+ argv[2] = "-u";
+ argv[3] = (char *)group;
+ argv[4] = NULL;
+
+ /* minimal command environment taken from cpu_run_sbin_hotplug */
+ envp[0] = "HOME=/";
+ envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
+ envp[2] = NULL;
+
+ ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+ if (ret < 0) {
+ printk(KERN_ERR
+ "ocfs2: Error %d running user helper "
+ "\"%s %s %s %s\"\n",
+ ret, argv[0], argv[1], argv[2], argv[3]);
+ }
+}
+
+/*
+ * Hangup is a required post-umount. ocfs2-tools software expects the
+ * filesystem to call "ocfs2_hb_ctl" during unmount. This happens
+ * regardless of whether the DLM got started, so we can't do it
+ * in ocfs2_cluster_disconnect(). The ocfs2_leave_group() function does
+ * the actual work.
+ */
+void ocfs2_cluster_hangup(const char *group, int grouplen)
+{
+ BUG_ON(group == NULL);
+ BUG_ON(group[grouplen] != '\0');
+
+ ocfs2_leave_group(group);
+
+ /* cluster_disconnect() was called with hangup_pending==1 */
+ ocfs2_stack_driver_put();
+}
+EXPORT_SYMBOL_GPL(ocfs2_cluster_hangup);
+
+int ocfs2_cluster_this_node(struct ocfs2_cluster_connection *conn,
+ unsigned int *node)
+{
+ return active_stack->sp_ops->this_node(conn, node);
+}
+EXPORT_SYMBOL_GPL(ocfs2_cluster_this_node);
+
+
+/*
+ * Sysfs bits
+ */
+
+static ssize_t ocfs2_max_locking_protocol_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = 0;
+
+ spin_lock(&ocfs2_stack_lock);
+ if (locking_max_version.pv_major)
+ ret = snprintf(buf, PAGE_SIZE, "%u.%u\n",
+ locking_max_version.pv_major,
+ locking_max_version.pv_minor);
+ spin_unlock(&ocfs2_stack_lock);
+
+ return ret;
+}
+
+static struct kobj_attribute ocfs2_attr_max_locking_protocol =
+ __ATTR(max_locking_protocol, S_IRUGO,
+ ocfs2_max_locking_protocol_show, NULL);
+
+static ssize_t ocfs2_loaded_cluster_plugins_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = 0, total = 0, remain = PAGE_SIZE;
+ struct ocfs2_stack_plugin *p;
+
+ spin_lock(&ocfs2_stack_lock);
+ list_for_each_entry(p, &ocfs2_stack_list, sp_list) {
+ ret = snprintf(buf, remain, "%s\n",
+ p->sp_name);
+ if (ret >= remain) {
+ /* snprintf() didn't fit */
+ total = -E2BIG;
+ break;
+ }
+ total += ret;
+ remain -= ret;
+ }
+ spin_unlock(&ocfs2_stack_lock);
+
+ return total;
+}
+
+static struct kobj_attribute ocfs2_attr_loaded_cluster_plugins =
+ __ATTR(loaded_cluster_plugins, S_IRUGO,
+ ocfs2_loaded_cluster_plugins_show, NULL);
+
+static ssize_t ocfs2_active_cluster_plugin_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ ssize_t ret = 0;
+
+ spin_lock(&ocfs2_stack_lock);
+ if (active_stack) {
+ ret = snprintf(buf, PAGE_SIZE, "%s\n",
+ active_stack->sp_name);
+ if (ret >= PAGE_SIZE)
+ ret = -E2BIG;
+ }
+ spin_unlock(&ocfs2_stack_lock);
+
+ return ret;
+}
+
+static struct kobj_attribute ocfs2_attr_active_cluster_plugin =
+ __ATTR(active_cluster_plugin, S_IRUGO,
+ ocfs2_active_cluster_plugin_show, NULL);
+
+static ssize_t ocfs2_cluster_stack_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ ssize_t ret;
+ spin_lock(&ocfs2_stack_lock);
+ ret = snprintf(buf, PAGE_SIZE, "%s\n", cluster_stack_name);
+ spin_unlock(&ocfs2_stack_lock);
+
+ return ret;
+}
+
+static ssize_t ocfs2_cluster_stack_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ size_t len = count;
+ ssize_t ret;
+
+ if (len == 0)
+ return len;
+
+ if (buf[len - 1] == '\n')
+ len--;
+
+ if ((len != OCFS2_STACK_LABEL_LEN) ||
+ (strnlen(buf, len) != len))
+ return -EINVAL;
+
+ spin_lock(&ocfs2_stack_lock);
+ if (active_stack) {
+ if (!strncmp(buf, cluster_stack_name, len))
+ ret = count;
+ else
+ ret = -EBUSY;
+ } else {
+ memcpy(cluster_stack_name, buf, len);
+ ret = count;
+ }
+ spin_unlock(&ocfs2_stack_lock);
+
+ return ret;
+}
+
+
+static struct kobj_attribute ocfs2_attr_cluster_stack =
+ __ATTR(cluster_stack, S_IRUGO | S_IWUSR,
+ ocfs2_cluster_stack_show,
+ ocfs2_cluster_stack_store);
+
+
+
+static ssize_t ocfs2_dlm_recover_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "1\n");
+}
+
+static struct kobj_attribute ocfs2_attr_dlm_recover_support =
+ __ATTR(dlm_recover_callback_support, S_IRUGO,
+ ocfs2_dlm_recover_show, NULL);
+
+static struct attribute *ocfs2_attrs[] = {
+ &ocfs2_attr_max_locking_protocol.attr,
+ &ocfs2_attr_loaded_cluster_plugins.attr,
+ &ocfs2_attr_active_cluster_plugin.attr,
+ &ocfs2_attr_cluster_stack.attr,
+ &ocfs2_attr_dlm_recover_support.attr,
+ NULL,
+};
+
+static const struct attribute_group ocfs2_attr_group = {
+ .attrs = ocfs2_attrs,
+};
+
+struct kset *ocfs2_kset;
+EXPORT_SYMBOL_GPL(ocfs2_kset);
+
+static void ocfs2_sysfs_exit(void)
+{
+ kset_unregister(ocfs2_kset);
+}
+
+static int ocfs2_sysfs_init(void)
+{
+ int ret;
+
+ ocfs2_kset = kset_create_and_add("ocfs2", NULL, fs_kobj);
+ if (!ocfs2_kset)
+ return -ENOMEM;
+
+ ret = sysfs_create_group(&ocfs2_kset->kobj, &ocfs2_attr_group);
+ if (ret)
+ goto error;
+
+ return 0;
+
+error:
+ kset_unregister(ocfs2_kset);
+ return ret;
+}
+
+/*
+ * Sysctl bits
+ *
+ * The sysctl lives at /proc/sys/fs/ocfs2/nm/hb_ctl_path. The 'nm' doesn't
+ * make as much sense in a multiple cluster stack world, but it's safer
+ * and easier to preserve the name.
+ */
+
+static struct ctl_table ocfs2_nm_table[] = {
+ {
+ .procname = "hb_ctl_path",
+ .data = ocfs2_hb_ctl_path,
+ .maxlen = OCFS2_MAX_HB_CTL_PATH,
+ .mode = 0644,
+ .proc_handler = proc_dostring,
+ },
+ { }
+};
+
+static struct ctl_table_header *ocfs2_table_header;
+
+/*
+ * Initialization
+ */
+
+static int __init ocfs2_stack_glue_init(void)
+{
+ int ret;
+
+ strcpy(cluster_stack_name, OCFS2_STACK_PLUGIN_O2CB);
+
+ ocfs2_table_header = register_sysctl("fs/ocfs2/nm", ocfs2_nm_table);
+ if (!ocfs2_table_header) {
+ printk(KERN_ERR
+ "ocfs2 stack glue: unable to register sysctl\n");
+ return -ENOMEM; /* or something. */
+ }
+
+ ret = ocfs2_sysfs_init();
+ if (ret)
+ unregister_sysctl_table(ocfs2_table_header);
+
+ return ret;
+}
+
+static void __exit ocfs2_stack_glue_exit(void)
+{
+ memset(&locking_max_version, 0,
+ sizeof(struct ocfs2_protocol_version));
+ ocfs2_sysfs_exit();
+ if (ocfs2_table_header)
+ unregister_sysctl_table(ocfs2_table_header);
+}
+
+MODULE_AUTHOR("Oracle");
+MODULE_DESCRIPTION("ocfs2 cluster stack glue layer");
+MODULE_LICENSE("GPL");
+module_init(ocfs2_stack_glue_init);
+module_exit(ocfs2_stack_glue_exit);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 17:48:51 +0000