1 files changed, 349 insertions, 96 deletions

diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index 7428663f9cb..13a8537d8e8 100644
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -21,12 +21,14 @@
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/mutex.h>
+#include <linux/slab.h>
 #include <linux/reboot.h>
+#include <linux/sched.h>
 #include <asm/uaccess.h>
 
-#include "ocfs2.h"  /* For struct ocfs2_lock_res */
 #include "stackglue.h"
 
+#include <linux/dlm_plock.h>
 
 /*
  * The control protocol starts with a handshake.  Until the handshake
@@ -61,8 +63,8 @@
  * negotiated by the client.  The client negotiates based on the maximum
  * version advertised in /sys/fs/ocfs2/max_locking_protocol.  The major
  * number from the "SETV" message must match
- * user_stack.sp_proto->lp_max_version.pv_major, and the minor number
- * must be less than or equal to ...->lp_max_version.pv_minor.
+ * ocfs2_user_plugin.sp_max_proto.pv_major, and the minor number
+ * must be less than or equal to ...sp_max_version.pv_minor.
  *
  * Once this information has been set, mounts will be allowed.  From this
  * point on, the "DOWN" message can be sent for node down notification.
@@ -101,6 +103,12 @@
 #define OCFS2_TEXT_UUID_LEN			32
 #define OCFS2_CONTROL_MESSAGE_VERNUM_LEN	2
 #define OCFS2_CONTROL_MESSAGE_NODENUM_LEN	8
+#define VERSION_LOCK				"version_lock"
+
+enum ocfs2_connection_type {
+	WITH_CONTROLD,
+	NO_CONTROLD
+};
 
 /*
  * ocfs2_live_connection is refcounted because the filesystem and
@@ -109,6 +117,13 @@
 struct ocfs2_live_connection {
 	struct list_head		oc_list;
 	struct ocfs2_cluster_connection	*oc_conn;
+	enum ocfs2_connection_type	oc_type;
+	atomic_t                        oc_this_node;
+	int                             oc_our_slot;
+	struct dlm_lksb                 oc_version_lksb;
+	char                            oc_lvb[DLM_LVB_LEN];
+	struct completion               oc_sync_wait;
+	wait_queue_head_t		oc_wait;
 };
 
 struct ocfs2_control_private {
@@ -153,7 +168,7 @@ union ocfs2_control_message {
 	struct ocfs2_control_message_down	u_down;
 };
 
-static struct ocfs2_stack_plugin user_stack;
+static struct ocfs2_stack_plugin ocfs2_user_plugin;
 
 static atomic_t ocfs2_control_opened;
 static int ocfs2_control_this_node = -1;
@@ -189,7 +204,7 @@ static struct ocfs2_live_connection *ocfs2_connection_find(const char *name)
 			return c;
 	}
 
-	return c;
+	return NULL;
 }
 
 /*
@@ -197,20 +212,15 @@ static struct ocfs2_live_connection *ocfs2_connection_find(const char *name)
  * mount path.  Since the VFS prevents multiple calls to
  * fill_super(), we can't get dupes here.
  */
-static int ocfs2_live_connection_new(struct ocfs2_cluster_connection *conn,
-				     struct ocfs2_live_connection **c_ret)
+static int ocfs2_live_connection_attach(struct ocfs2_cluster_connection *conn,
+				     struct ocfs2_live_connection *c)
 {
 	int rc = 0;
-	struct ocfs2_live_connection *c;
-
-	c = kzalloc(sizeof(struct ocfs2_live_connection), GFP_KERNEL);
-	if (!c)
-		return -ENOMEM;
 
 	mutex_lock(&ocfs2_control_lock);
 	c->oc_conn = conn;
 
-	if (atomic_read(&ocfs2_control_opened))
+	if ((c->oc_type == NO_CONTROLD) || atomic_read(&ocfs2_control_opened))
 		list_add(&c->oc_list, &ocfs2_live_connection_list);
 	else {
 		printk(KERN_ERR
@@ -219,12 +229,6 @@ static int ocfs2_live_connection_new(struct ocfs2_cluster_connection *conn,
 	}
 
 	mutex_unlock(&ocfs2_control_lock);
-
-	if (!rc)
-		*c_ret = c;
-	else
-		kfree(c);
-
 	return rc;
 }
 
@@ -399,7 +403,7 @@ static int ocfs2_control_do_setversion_msg(struct file *file,
 	char *ptr = NULL;
 	struct ocfs2_control_private *p = file->private_data;
 	struct ocfs2_protocol_version *max =
-		&user_stack.sp_proto->lp_max_version;
+		&ocfs2_user_plugin.sp_max_proto;
 
 	if (ocfs2_control_get_handshake_state(file) !=
 	    OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
@@ -549,26 +553,17 @@ static ssize_t ocfs2_control_read(struct file *file,
 				  size_t count,
 				  loff_t *ppos)
 {
-	char *proto_string = OCFS2_CONTROL_PROTO;
-	size_t to_write = 0;
-
-	if (*ppos >= OCFS2_CONTROL_PROTO_LEN)
-		return 0;
-
-	to_write = OCFS2_CONTROL_PROTO_LEN - *ppos;
-	if (to_write > count)
-		to_write = count;
-	if (copy_to_user(buf, proto_string + *ppos, to_write))
-		return -EFAULT;
+	ssize_t ret;
 
-	*ppos += to_write;
+	ret = simple_read_from_buffer(buf, count, ppos,
+			OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN);
 
 	/* Have we read the whole protocol list? */
-	if (*ppos >= OCFS2_CONTROL_PROTO_LEN)
+	if (ret > 0 && *ppos >= OCFS2_CONTROL_PROTO_LEN)
 		ocfs2_control_set_handshake_state(file,
 						  OCFS2_CONTROL_HANDSHAKE_READ);
 
-	return to_write;
+	return ret;
 }
 
 static int ocfs2_control_release(struct inode *inode, struct file *file)
@@ -633,9 +628,10 @@ static const struct file_operations ocfs2_control_fops = {
 	.read    = ocfs2_control_read,
 	.write   = ocfs2_control_write,
 	.owner   = THIS_MODULE,
+	.llseek  = default_llseek,
 };
 
-struct miscdevice ocfs2_control_device = {
+static struct miscdevice ocfs2_control_device = {
 	.minor		= MISC_DYNAMIC_MINOR,
 	.name		= "ocfs2_control",
 	.fops		= &ocfs2_control_fops,
@@ -669,18 +665,10 @@ static void ocfs2_control_exit(void)
 		       -rc);
 }
 
-static struct dlm_lksb *fsdlm_astarg_to_lksb(void *astarg)
-{
-	struct ocfs2_lock_res *res = astarg;
-	return &res->l_lksb.lksb_fsdlm;
-}
-
 static void fsdlm_lock_ast_wrapper(void *astarg)
 {
-	struct dlm_lksb *lksb = fsdlm_astarg_to_lksb(astarg);
-	int status = lksb->sb_status;
-
-	BUG_ON(user_stack.sp_proto == NULL);
+	struct ocfs2_dlm_lksb *lksb = astarg;
+	int status = lksb->lksb_fsdlm.sb_status;
 
 	/*
 	 * For now we're punting on the issue of other non-standard errors
@@ -693,25 +681,24 @@ static void fsdlm_lock_ast_wrapper(void *astarg)
 	 */
 
 	if (status == -DLM_EUNLOCK || status == -DLM_ECANCEL)
-		user_stack.sp_proto->lp_unlock_ast(astarg, 0);
+		lksb->lksb_conn->cc_proto->lp_unlock_ast(lksb, 0);
 	else
-		user_stack.sp_proto->lp_lock_ast(astarg);
+		lksb->lksb_conn->cc_proto->lp_lock_ast(lksb);
 }
 
 static void fsdlm_blocking_ast_wrapper(void *astarg, int level)
 {
-	BUG_ON(user_stack.sp_proto == NULL);
+	struct ocfs2_dlm_lksb *lksb = astarg;
 
-	user_stack.sp_proto->lp_blocking_ast(astarg, level);
+	lksb->lksb_conn->cc_proto->lp_blocking_ast(lksb, level);
 }
 
 static int user_dlm_lock(struct ocfs2_cluster_connection *conn,
 			 int mode,
-			 union ocfs2_dlm_lksb *lksb,
+			 struct ocfs2_dlm_lksb *lksb,
 			 u32 flags,
 			 void *name,
-			 unsigned int namelen,
-			 void *astarg)
+			 unsigned int namelen)
 {
 	int ret;
 
@@ -721,37 +708,77 @@ static int user_dlm_lock(struct ocfs2_cluster_connection *conn,
 
 	ret = dlm_lock(conn->cc_lockspace, mode, &lksb->lksb_fsdlm,
 		       flags|DLM_LKF_NODLCKWT, name, namelen, 0,
-		       fsdlm_lock_ast_wrapper, astarg,
+		       fsdlm_lock_ast_wrapper, lksb,
 		       fsdlm_blocking_ast_wrapper);
 	return ret;
 }
 
 static int user_dlm_unlock(struct ocfs2_cluster_connection *conn,
-			   union ocfs2_dlm_lksb *lksb,
-			   u32 flags,
-			   void *astarg)
+			   struct ocfs2_dlm_lksb *lksb,
+			   u32 flags)
 {
 	int ret;
 
 	ret = dlm_unlock(conn->cc_lockspace, lksb->lksb_fsdlm.sb_lkid,
-			 flags, &lksb->lksb_fsdlm, astarg);
+			 flags, &lksb->lksb_fsdlm, lksb);
 	return ret;
 }
 
-static int user_dlm_lock_status(union ocfs2_dlm_lksb *lksb)
+static int user_dlm_lock_status(struct ocfs2_dlm_lksb *lksb)
 {
 	return lksb->lksb_fsdlm.sb_status;
 }
 
-static void *user_dlm_lvb(union ocfs2_dlm_lksb *lksb)
+static int user_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb)
 {
+	int invalid = lksb->lksb_fsdlm.sb_flags & DLM_SBF_VALNOTVALID;
+
+	return !invalid;
+}
+
+static void *user_dlm_lvb(struct ocfs2_dlm_lksb *lksb)
+{
+	if (!lksb->lksb_fsdlm.sb_lvbptr)
+		lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb +
+					     sizeof(struct dlm_lksb);
 	return (void *)(lksb->lksb_fsdlm.sb_lvbptr);
 }
 
-static void user_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb)
+static void user_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb)
 {
 }
 
+static int user_plock(struct ocfs2_cluster_connection *conn,
+		      u64 ino,
+		      struct file *file,
+		      int cmd,
+		      struct file_lock *fl)
+{
+	/*
+	 * This more or less just demuxes the plock request into any
+	 * one of three dlm calls.
+	 *
+	 * Internally, fs/dlm will pass these to a misc device, which
+	 * a userspace daemon will read and write to.
+	 *
+	 * For now, cancel requests (which happen internally only),
+	 * are turned into unlocks. Most of this function taken from
+	 * gfs2_lock.
+	 */
+
+	if (cmd == F_CANCELLK) {
+		cmd = F_SETLK;
+		fl->fl_type = F_UNLCK;
+	}
+
+	if (IS_GETLK(cmd))
+		return dlm_posix_get(conn->cc_lockspace, ino, file, fl);
+	else if (fl->fl_type == F_UNLCK)
+		return dlm_posix_unlock(conn->cc_lockspace, ino, file, fl);
+	else
+		return dlm_posix_lock(conn->cc_lockspace, ino, file, cmd, fl);
+}
+
 /*
  * Compare a requested locking protocol version against the current one.
  *
@@ -775,18 +802,251 @@ static int fs_protocol_compare(struct ocfs2_protocol_version *existing,
 	return 0;
 }
 
+static void lvb_to_version(char *lvb, struct ocfs2_protocol_version *ver)
+{
+	struct ocfs2_protocol_version *pv =
+		(struct ocfs2_protocol_version *)lvb;
+	/*
+	 * ocfs2_protocol_version has two u8 variables, so we don't
+	 * need any endian conversion.
+	 */
+	ver->pv_major = pv->pv_major;
+	ver->pv_minor = pv->pv_minor;
+}
+
+static void version_to_lvb(struct ocfs2_protocol_version *ver, char *lvb)
+{
+	struct ocfs2_protocol_version *pv =
+		(struct ocfs2_protocol_version *)lvb;
+	/*
+	 * ocfs2_protocol_version has two u8 variables, so we don't
+	 * need any endian conversion.
+	 */
+	pv->pv_major = ver->pv_major;
+	pv->pv_minor = ver->pv_minor;
+}
+
+static void sync_wait_cb(void *arg)
+{
+	struct ocfs2_cluster_connection *conn = arg;
+	struct ocfs2_live_connection *lc = conn->cc_private;
+	complete(&lc->oc_sync_wait);
+}
+
+static int sync_unlock(struct ocfs2_cluster_connection *conn,
+		struct dlm_lksb *lksb, char *name)
+{
+	int error;
+	struct ocfs2_live_connection *lc = conn->cc_private;
+
+	error = dlm_unlock(conn->cc_lockspace, lksb->sb_lkid, 0, lksb, conn);
+	if (error) {
+		printk(KERN_ERR "%s lkid %x error %d\n",
+				name, lksb->sb_lkid, error);
+		return error;
+	}
+
+	wait_for_completion(&lc->oc_sync_wait);
+
+	if (lksb->sb_status != -DLM_EUNLOCK) {
+		printk(KERN_ERR "%s lkid %x status %d\n",
+				name, lksb->sb_lkid, lksb->sb_status);
+		return -1;
+	}
+	return 0;
+}
+
+static int sync_lock(struct ocfs2_cluster_connection *conn,
+		int mode, uint32_t flags,
+		struct dlm_lksb *lksb, char *name)
+{
+	int error, status;
+	struct ocfs2_live_connection *lc = conn->cc_private;
+
+	error = dlm_lock(conn->cc_lockspace, mode, lksb, flags,
+			name, strlen(name),
+			0, sync_wait_cb, conn, NULL);
+	if (error) {
+		printk(KERN_ERR "%s lkid %x flags %x mode %d error %d\n",
+				name, lksb->sb_lkid, flags, mode, error);
+		return error;
+	}
+
+	wait_for_completion(&lc->oc_sync_wait);
+
+	status = lksb->sb_status;
+
+	if (status && status != -EAGAIN) {
+		printk(KERN_ERR "%s lkid %x flags %x mode %d status %d\n",
+				name, lksb->sb_lkid, flags, mode, status);
+	}
+
+	return status;
+}
+
+
+static int version_lock(struct ocfs2_cluster_connection *conn, int mode,
+		int flags)
+{
+	struct ocfs2_live_connection *lc = conn->cc_private;
+	return sync_lock(conn, mode, flags,
+			&lc->oc_version_lksb, VERSION_LOCK);
+}
+
+static int version_unlock(struct ocfs2_cluster_connection *conn)
+{
+	struct ocfs2_live_connection *lc = conn->cc_private;
+	return sync_unlock(conn, &lc->oc_version_lksb, VERSION_LOCK);
+}
+
+/* get_protocol_version()
+ *
+ * To exchange ocfs2 versioning, we use the LVB of the version dlm lock.
+ * The algorithm is:
+ * 1. Attempt to take the lock in EX mode (non-blocking).
+ * 2. If successful (which means it is the first mount), write the
+ *    version number and downconvert to PR lock.
+ * 3. If unsuccessful (returns -EAGAIN), read the version from the LVB after
+ *    taking the PR lock.
+ */
+
+static int get_protocol_version(struct ocfs2_cluster_connection *conn)
+{
+	int ret;
+	struct ocfs2_live_connection *lc = conn->cc_private;
+	struct ocfs2_protocol_version pv;
+
+	running_proto.pv_major =
+		ocfs2_user_plugin.sp_max_proto.pv_major;
+	running_proto.pv_minor =
+		ocfs2_user_plugin.sp_max_proto.pv_minor;
+
+	lc->oc_version_lksb.sb_lvbptr = lc->oc_lvb;
+	ret = version_lock(conn, DLM_LOCK_EX,
+			DLM_LKF_VALBLK|DLM_LKF_NOQUEUE);
+	if (!ret) {
+		conn->cc_version.pv_major = running_proto.pv_major;
+		conn->cc_version.pv_minor = running_proto.pv_minor;
+		version_to_lvb(&running_proto, lc->oc_lvb);
+		version_lock(conn, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
+	} else if (ret == -EAGAIN) {
+		ret = version_lock(conn, DLM_LOCK_PR, DLM_LKF_VALBLK);
+		if (ret)
+			goto out;
+		lvb_to_version(lc->oc_lvb, &pv);
+
+		if ((pv.pv_major != running_proto.pv_major) ||
+				(pv.pv_minor > running_proto.pv_minor)) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		conn->cc_version.pv_major = pv.pv_major;
+		conn->cc_version.pv_minor = pv.pv_minor;
+	}
+out:
+	return ret;
+}
+
+static void user_recover_prep(void *arg)
+{
+}
+
+static void user_recover_slot(void *arg, struct dlm_slot *slot)
+{
+	struct ocfs2_cluster_connection *conn = arg;
+	printk(KERN_INFO "ocfs2: Node %d/%d down. Initiating recovery.\n",
+			slot->nodeid, slot->slot);
+	conn->cc_recovery_handler(slot->nodeid, conn->cc_recovery_data);
+
+}
+
+static void user_recover_done(void *arg, struct dlm_slot *slots,
+		int num_slots, int our_slot,
+		uint32_t generation)
+{
+	struct ocfs2_cluster_connection *conn = arg;
+	struct ocfs2_live_connection *lc = conn->cc_private;
+	int i;
+
+	for (i = 0; i < num_slots; i++)
+		if (slots[i].slot == our_slot) {
+			atomic_set(&lc->oc_this_node, slots[i].nodeid);
+			break;
+		}
+
+	lc->oc_our_slot = our_slot;
+	wake_up(&lc->oc_wait);
+}
+
+static const struct dlm_lockspace_ops ocfs2_ls_ops = {
+	.recover_prep = user_recover_prep,
+	.recover_slot = user_recover_slot,
+	.recover_done = user_recover_done,
+};
+
+static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
+{
+	version_unlock(conn);
+	dlm_release_lockspace(conn->cc_lockspace, 2);
+	conn->cc_lockspace = NULL;
+	ocfs2_live_connection_drop(conn->cc_private);
+	conn->cc_private = NULL;
+	return 0;
+}
+
 static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
 {
 	dlm_lockspace_t *fsdlm;
-	struct ocfs2_live_connection *control;
-	int rc = 0;
+	struct ocfs2_live_connection *lc;
+	int rc, ops_rv;
 
 	BUG_ON(conn == NULL);
 
-	rc = ocfs2_live_connection_new(conn, &control);
+	lc = kzalloc(sizeof(struct ocfs2_live_connection), GFP_KERNEL);
+	if (!lc) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	init_waitqueue_head(&lc->oc_wait);
+	init_completion(&lc->oc_sync_wait);
+	atomic_set(&lc->oc_this_node, 0);
+	conn->cc_private = lc;
+	lc->oc_type = NO_CONTROLD;
+
+	rc = dlm_new_lockspace(conn->cc_name, conn->cc_cluster_name,
+			       DLM_LSFL_FS, DLM_LVB_LEN,
+			       &ocfs2_ls_ops, conn, &ops_rv, &fsdlm);
 	if (rc)
 		goto out;
 
+	if (ops_rv == -EOPNOTSUPP) {
+		lc->oc_type = WITH_CONTROLD;
+		printk(KERN_NOTICE "ocfs2: You seem to be using an older "
+				"version of dlm_controld and/or ocfs2-tools."
+				" Please consider upgrading.\n");
+	} else if (ops_rv) {
+		rc = ops_rv;
+		goto out;
+	}
+	conn->cc_lockspace = fsdlm;
+
+	rc = ocfs2_live_connection_attach(conn, lc);
+	if (rc)
+		goto out;
+
+	if (lc->oc_type == NO_CONTROLD) {
+		rc = get_protocol_version(conn);
+		if (rc) {
+			printk(KERN_ERR "ocfs2: Could not determine"
+					" locking version\n");
+			user_cluster_disconnect(conn);
+			goto out;
+		}
+		wait_event(lc->oc_wait, (atomic_read(&lc->oc_this_node) > 0));
+	}
+
 	/*
 	 * running_proto must have been set before we allowed any mounts
 	 * to proceed.
@@ -794,43 +1054,34 @@ static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
 	if (fs_protocol_compare(&running_proto, &conn->cc_version)) {
 		printk(KERN_ERR
 		       "Unable to mount with fs locking protocol version "
-		       "%u.%u because the userspace control daemon has "
-		       "negotiated %u.%u\n",
+		       "%u.%u because negotiated protocol is %u.%u\n",
 		       conn->cc_version.pv_major, conn->cc_version.pv_minor,
 		       running_proto.pv_major, running_proto.pv_minor);
 		rc = -EPROTO;
-		ocfs2_live_connection_drop(control);
-		goto out;
+		ocfs2_live_connection_drop(lc);
+		lc = NULL;
 	}
 
-	rc = dlm_new_lockspace(conn->cc_name, strlen(conn->cc_name),
-			       &fsdlm, DLM_LSFL_FS, DLM_LVB_LEN);
-	if (rc) {
-		ocfs2_live_connection_drop(control);
-		goto out;
-	}
-
-	conn->cc_private = control;
-	conn->cc_lockspace = fsdlm;
 out:
+	if (rc && lc)
+		kfree(lc);
 	return rc;
 }
 
-static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn,
-				   int hangup_pending)
-{
-	dlm_release_lockspace(conn->cc_lockspace, 2);
-	conn->cc_lockspace = NULL;
-	ocfs2_live_connection_drop(conn->cc_private);
-	conn->cc_private = NULL;
-	return 0;
-}
 
-static int user_cluster_this_node(unsigned int *this_node)
+static int user_cluster_this_node(struct ocfs2_cluster_connection *conn,
+				  unsigned int *this_node)
 {
 	int rc;
+	struct ocfs2_live_connection *lc = conn->cc_private;
+
+	if (lc->oc_type == WITH_CONTROLD)
+		rc = ocfs2_control_get_this_node();
+	else if (lc->oc_type == NO_CONTROLD)
+		rc = atomic_read(&lc->oc_this_node);
+	else
+		rc = -EINVAL;
 
-	rc = ocfs2_control_get_this_node();
 	if (rc < 0)
 		return rc;
 
@@ -838,31 +1089,33 @@ static int user_cluster_this_node(unsigned int *this_node)
 	return 0;
 }
 
-static struct ocfs2_stack_operations user_stack_ops = {
+static struct ocfs2_stack_operations ocfs2_user_plugin_ops = {
 	.connect	= user_cluster_connect,
 	.disconnect	= user_cluster_disconnect,
 	.this_node	= user_cluster_this_node,
 	.dlm_lock	= user_dlm_lock,
 	.dlm_unlock	= user_dlm_unlock,
 	.lock_status	= user_dlm_lock_status,
+	.lvb_valid	= user_dlm_lvb_valid,
 	.lock_lvb	= user_dlm_lvb,
+	.plock		= user_plock,
 	.dump_lksb	= user_dlm_dump_lksb,
 };
 
-static struct ocfs2_stack_plugin user_stack = {
+static struct ocfs2_stack_plugin ocfs2_user_plugin = {
 	.sp_name	= "user",
-	.sp_ops		= &user_stack_ops,
+	.sp_ops		= &ocfs2_user_plugin_ops,
 	.sp_owner	= THIS_MODULE,
 };
 
 
-static int __init user_stack_init(void)
+static int __init ocfs2_user_plugin_init(void)
 {
 	int rc;
 
 	rc = ocfs2_control_init();
 	if (!rc) {
-		rc = ocfs2_stack_glue_register(&user_stack);
+		rc = ocfs2_stack_glue_register(&ocfs2_user_plugin);
 		if (rc)
 			ocfs2_control_exit();
 	}
@@ -870,14 +1123,14 @@ static int __init user_stack_init(void)
 	return rc;
 }
 
-static void __exit user_stack_exit(void)
+static void __exit ocfs2_user_plugin_exit(void)
 {
-	ocfs2_stack_glue_unregister(&user_stack);
+	ocfs2_stack_glue_unregister(&ocfs2_user_plugin);
 	ocfs2_control_exit();
 }
 
 MODULE_AUTHOR("Oracle");
 MODULE_DESCRIPTION("ocfs2 driver for userspace cluster stacks");
 MODULE_LICENSE("GPL");
-module_init(user_stack_init);
-module_exit(user_stack_exit);
+module_init(ocfs2_user_plugin_init);
+module_exit(ocfs2_user_plugin_exit);