[PATCH] OCFS2: The Second Oracle Cluster Filesystem

The OCFS2 file system module.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>

1 files changed, 2904 insertions, 0 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
new file mode 100644
index 0000000..e971ec2
--- /dev/null
+++ b/fs/ocfs2/dlmglue.c
@@ -0,0 +1,2904 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * dlmglue.c
+ *
+ * Code which implements an OCFS2 specific interface to our DLM.
+ *
+ * Copyright (C) 2003, 2004 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/smp_lock.h>
+#include <linux/crc32.h>
+#include <linux/kthread.h>
+#include <linux/pagemap.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include <cluster/heartbeat.h>
+#include <cluster/nodemanager.h>
+#include <cluster/tcp.h>
+
+#include <dlm/dlmapi.h>
+
+#define MLOG_MASK_PREFIX ML_DLM_GLUE
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "alloc.h"
+#include "dlmglue.h"
+#include "extent_map.h"
+#include "heartbeat.h"
+#include "inode.h"
+#include "journal.h"
+#include "slot_map.h"
+#include "super.h"
+#include "uptodate.h"
+#include "vote.h"
+
+#include "buffer_head_io.h"
+
+struct ocfs2_mask_waiter {
+	struct list_head	mw_item;
+	int			mw_status;
+	struct completion	mw_complete;
+	unsigned long		mw_mask;
+	unsigned long		mw_goal;
+};
+
+static void ocfs2_inode_ast_func(void *opaque);
+static void ocfs2_inode_bast_func(void *opaque,
+				  int level);
+static void ocfs2_super_ast_func(void *opaque);
+static void ocfs2_super_bast_func(void *opaque,
+				  int level);
+static void ocfs2_rename_ast_func(void *opaque);
+static void ocfs2_rename_bast_func(void *opaque,
+				   int level);
+
+/* so far, all locks have gotten along with the same unlock ast */
+static void ocfs2_unlock_ast_func(void *opaque,
+				  enum dlm_status status);
+static int ocfs2_do_unblock_meta(struct inode *inode,
+				 int *requeue);
+static int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres,
+			      int *requeue);
+static int ocfs2_unblock_data(struct ocfs2_lock_res *lockres,
+			      int *requeue);
+static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres,
+			      int *requeue);
+static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres,
+				  int *requeue);
+typedef void (ocfs2_convert_worker_t)(struct ocfs2_lock_res *, int);
+static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb,
+				      struct ocfs2_lock_res *lockres,
+				      int *requeue,
+				      ocfs2_convert_worker_t *worker);
+
+struct ocfs2_lock_res_ops {
+	void (*ast)(void *);
+	void (*bast)(void *, int);
+	void (*unlock_ast)(void *, enum dlm_status);
+	int  (*unblock)(struct ocfs2_lock_res *, int *);
+};
+
+static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
+	.ast		= ocfs2_inode_ast_func,
+	.bast		= ocfs2_inode_bast_func,
+	.unlock_ast	= ocfs2_unlock_ast_func,
+	.unblock	= ocfs2_unblock_inode_lock,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_inode_meta_lops = {
+	.ast		= ocfs2_inode_ast_func,
+	.bast		= ocfs2_inode_bast_func,
+	.unlock_ast	= ocfs2_unlock_ast_func,
+	.unblock	= ocfs2_unblock_meta,
+};
+
+static void ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
+				      int blocking);
+
+static struct ocfs2_lock_res_ops ocfs2_inode_data_lops = {
+	.ast		= ocfs2_inode_ast_func,
+	.bast		= ocfs2_inode_bast_func,
+	.unlock_ast	= ocfs2_unlock_ast_func,
+	.unblock	= ocfs2_unblock_data,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_super_lops = {
+	.ast		= ocfs2_super_ast_func,
+	.bast		= ocfs2_super_bast_func,
+	.unlock_ast	= ocfs2_unlock_ast_func,
+	.unblock	= ocfs2_unblock_osb_lock,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
+	.ast		= ocfs2_rename_ast_func,
+	.bast		= ocfs2_rename_bast_func,
+	.unlock_ast	= ocfs2_unlock_ast_func,
+	.unblock	= ocfs2_unblock_osb_lock,
+};
+
+static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
+{
+	return lockres->l_type == OCFS2_LOCK_TYPE_META ||
+		lockres->l_type == OCFS2_LOCK_TYPE_DATA ||
+		lockres->l_type == OCFS2_LOCK_TYPE_RW;
+}
+
+static inline int ocfs2_is_super_lock(struct ocfs2_lock_res *lockres)
+{
+	return lockres->l_type == OCFS2_LOCK_TYPE_SUPER;
+}
+
+static inline int ocfs2_is_rename_lock(struct ocfs2_lock_res *lockres)
+{
+	return lockres->l_type == OCFS2_LOCK_TYPE_RENAME;
+}
+
+static inline struct ocfs2_super *ocfs2_lock_res_super(struct ocfs2_lock_res *lockres)
+{
+	BUG_ON(!ocfs2_is_super_lock(lockres)
+	       && !ocfs2_is_rename_lock(lockres));
+
+	return (struct ocfs2_super *) lockres->l_priv;
+}
+
+static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
+{
+	BUG_ON(!ocfs2_is_inode_lock(lockres));
+
+	return (struct inode *) lockres->l_priv;
+}
+
+static int ocfs2_lock_create(struct ocfs2_super *osb,
+			     struct ocfs2_lock_res *lockres,
+			     int level,
+			     int dlm_flags);
+static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
+						     int wanted);
+static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
+				 struct ocfs2_lock_res *lockres,
+				 int level);
+static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres);
+static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres);
+static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres);
+static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level);
+static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
+					struct ocfs2_lock_res *lockres);
+static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
+						int convert);
+#define ocfs2_log_dlm_error(_func, _stat, _lockres) do {	\
+	mlog(ML_ERROR, "Dlm error \"%s\" while calling %s on "	\
+		"resource %s: %s\n", dlm_errname(_stat), _func,	\
+		_lockres->l_name, dlm_errmsg(_stat));		\
+} while (0)
+static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
+				 struct ocfs2_lock_res *lockres);
+static int ocfs2_meta_lock_update(struct inode *inode,
+				  struct buffer_head **bh);
+static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
+static inline int ocfs2_highest_compat_lock_level(int level);
+static inline int ocfs2_can_downconvert_meta_lock(struct inode *inode,
+						  struct ocfs2_lock_res *lockres,
+						  int new_level);
+
+static char *ocfs2_lock_type_strings[] = {
+	[OCFS2_LOCK_TYPE_META] = "Meta",
+	[OCFS2_LOCK_TYPE_DATA] = "Data",
+	[OCFS2_LOCK_TYPE_SUPER] = "Super",
+	[OCFS2_LOCK_TYPE_RENAME] = "Rename",
+	/* Need to differntiate from [R]ename.. serializing writes is the
+	 * important job it does, anyway. */
+	[OCFS2_LOCK_TYPE_RW] = "Write/Read",
+};
+
+static char *ocfs2_lock_type_string(enum ocfs2_lock_type type)
+{
+	mlog_bug_on_msg(type >= OCFS2_NUM_LOCK_TYPES, "%d\n", type);
+	return ocfs2_lock_type_strings[type];
+}
+
+static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
+				  u64 blkno,
+				  u32 generation,
+				  char *name)
+{
+	int len;
+
+	mlog_entry_void();
+
+	BUG_ON(type >= OCFS2_NUM_LOCK_TYPES);
+
+	len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016"MLFx64"%08x",
+		       ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD, blkno,
+		       generation);
+
+	BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1));
+
+	mlog(0, "built lock resource with name: %s\n", name);
+
+	mlog_exit_void();
+}
+
+static spinlock_t ocfs2_dlm_tracking_lock = SPIN_LOCK_UNLOCKED;
+
+static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res,
+				       struct ocfs2_dlm_debug *dlm_debug)
+{
+	mlog(0, "Add tracking for lockres %s\n", res->l_name);
+
+	spin_lock(&ocfs2_dlm_tracking_lock);
+	list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking);
+	spin_unlock(&ocfs2_dlm_tracking_lock);
+}
+
+static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
+{
+	spin_lock(&ocfs2_dlm_tracking_lock);
+	if (!list_empty(&res->l_debug_list))
+		list_del_init(&res->l_debug_list);
+	spin_unlock(&ocfs2_dlm_tracking_lock);
+}
+
+static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
+				       struct ocfs2_lock_res *res,
+				       enum ocfs2_lock_type type,
+				       u64 blkno,
+				       u32 generation,
+				       struct ocfs2_lock_res_ops *ops,
+				       void *priv)
+{
+	ocfs2_build_lock_name(type, blkno, generation, res->l_name);
+
+	res->l_type          = type;
+	res->l_ops           = ops;
+	res->l_priv          = priv;
+
+	res->l_level         = LKM_IVMODE;
+	res->l_requested     = LKM_IVMODE;
+	res->l_blocking      = LKM_IVMODE;
+	res->l_action        = OCFS2_AST_INVALID;
+	res->l_unlock_action = OCFS2_UNLOCK_INVALID;
+
+	res->l_flags         = OCFS2_LOCK_INITIALIZED;
+
+	ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug);
+}
+
+void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
+{
+	/* This also clears out the lock status block */
+	memset(res, 0, sizeof(struct ocfs2_lock_res));
+	spin_lock_init(&res->l_lock);
+	init_waitqueue_head(&res->l_event);
+	INIT_LIST_HEAD(&res->l_blocked_list);
+	INIT_LIST_HEAD(&res->l_mask_waiters);
+}
+
+void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
+			       enum ocfs2_lock_type type,
+			       struct inode *inode)
+{
+	struct ocfs2_lock_res_ops *ops;
+
+	switch(type) {
+		case OCFS2_LOCK_TYPE_RW:
+			ops = &ocfs2_inode_rw_lops;
+			break;
+		case OCFS2_LOCK_TYPE_META:
+			ops = &ocfs2_inode_meta_lops;
+			break;
+		case OCFS2_LOCK_TYPE_DATA:
+			ops = &ocfs2_inode_data_lops;
+			break;
+		default:
+			mlog_bug_on_msg(1, "type: %d\n", type);
+			ops = NULL; /* thanks, gcc */
+			break;
+	};
+
+	ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type,
+				   OCFS2_I(inode)->ip_blkno,
+				   inode->i_generation, ops, inode);
+}
+
+static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res,
+				      struct ocfs2_super *osb)
+{
+	/* Superblock lockres doesn't come from a slab so we call init
+	 * once on it manually.  */
+	ocfs2_lock_res_init_once(res);
+	ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER,
+				   OCFS2_SUPER_BLOCK_BLKNO, 0,
+				   &ocfs2_super_lops, osb);
+}
+
+static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
+				       struct ocfs2_super *osb)
+{
+	/* Rename lockres doesn't come from a slab so we call init
+	 * once on it manually.  */
+	ocfs2_lock_res_init_once(res);
+	ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME, 0, 0,
+				   &ocfs2_rename_lops, osb);
+}
+
+void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
+{
+	mlog_entry_void();
+
+	if (!(res->l_flags & OCFS2_LOCK_INITIALIZED))
+		return;
+
+	ocfs2_remove_lockres_tracking(res);
+
+	mlog_bug_on_msg(!list_empty(&res->l_blocked_list),
+			"Lockres %s is on the blocked list\n",
+			res->l_name);
+	mlog_bug_on_msg(!list_empty(&res->l_mask_waiters),
+			"Lockres %s has mask waiters pending\n",
+			res->l_name);
+	mlog_bug_on_msg(spin_is_locked(&res->l_lock),
+			"Lockres %s is locked\n",
+			res->l_name);
+	mlog_bug_on_msg(res->l_ro_holders,
+			"Lockres %s has %u ro holders\n",
+			res->l_name, res->l_ro_holders);
+	mlog_bug_on_msg(res->l_ex_holders,
+			"Lockres %s has %u ex holders\n",
+			res->l_name, res->l_ex_holders);
+
+	/* Need to clear out the lock status block for the dlm */
+	memset(&res->l_lksb, 0, sizeof(res->l_lksb));
+
+	res->l_flags = 0UL;
+	mlog_exit_void();
+}
+
+static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
+				     int level)
+{
+	mlog_entry_void();
+
+	BUG_ON(!lockres);
+
+	switch(level) {
+	case LKM_EXMODE:
+		lockres->l_ex_holders++;
+		break;
+	case LKM_PRMODE:
+		lockres->l_ro_holders++;
+		break;
+	default:
+		BUG();
+	}
+
+	mlog_exit_void();
+}
+
+static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
+				     int level)
+{
+	mlog_entry_void();
+
+	BUG_ON(!lockres);
+
+	switch(level) {
+	case LKM_EXMODE:
+		BUG_ON(!lockres->l_ex_holders);
+		lockres->l_ex_holders--;
+		break;
+	case LKM_PRMODE:
+		BUG_ON(!lockres->l_ro_holders);
+		lockres->l_ro_holders--;
+		break;
+	default:
+		BUG();
+	}
+	mlog_exit_void();
+}
+
+/* WARNING: This function lives in a world where the only three lock
+ * levels are EX, PR, and NL. It *will* have to be adjusted when more
+ * lock types are added. */
+static inline int ocfs2_highest_compat_lock_level(int level)
+{
+	int new_level = LKM_EXMODE;
+
+	if (level == LKM_EXMODE)
+		new_level = LKM_NLMODE;
+	else if (level == LKM_PRMODE)
+		new_level = LKM_PRMODE;
+	return new_level;
+}
+
+static void lockres_set_flags(struct ocfs2_lock_res *lockres,
+			      unsigned long newflags)
+{
+	struct list_head *pos, *tmp;
+	struct ocfs2_mask_waiter *mw;
+
+ 	assert_spin_locked(&lockres->l_lock);
+
+	lockres->l_flags = newflags;
+
+	list_for_each_safe(pos, tmp, &lockres->l_mask_waiters) {
+		mw = list_entry(pos, struct ocfs2_mask_waiter, mw_item);
+		if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
+			continue;
+
+		list_del_init(&mw->mw_item);
+		mw->mw_status = 0;
+		complete(&mw->mw_complete);
+	}
+}
+static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or)
+{
+	lockres_set_flags(lockres, lockres->l_flags | or);
+}
+static void lockres_clear_flags(struct ocfs2_lock_res *lockres,
+				unsigned long clear)
+{
+	lockres_set_flags(lockres, lockres->l_flags & ~clear);
+}
+
+static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres)
+{
+	mlog_entry_void();
+
+	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
+	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
+	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
+	BUG_ON(lockres->l_blocking <= LKM_NLMODE);
+
+	lockres->l_level = lockres->l_requested;
+	if (lockres->l_level <=
+	    ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
+		lockres->l_blocking = LKM_NLMODE;
+		lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
+	}
+	lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+
+	mlog_exit_void();
+}
+
+static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres)
+{
+	mlog_entry_void();
+
+	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
+	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
+
+	/* Convert from RO to EX doesn't really need anything as our
+	 * information is already up to data. Convert from NL to
+	 * *anything* however should mark ourselves as needing an
+	 * update */
+	if (lockres->l_level == LKM_NLMODE)
+		lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
+
+	lockres->l_level = lockres->l_requested;
+	lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+
+	mlog_exit_void();
+}
+
+static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres)
+{
+	mlog_entry_void();
+
+	BUG_ON((!lockres->l_flags & OCFS2_LOCK_BUSY));
+	BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
+
+	if (lockres->l_requested > LKM_NLMODE &&
+	    !(lockres->l_flags & OCFS2_LOCK_LOCAL))
+		lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
+
+	lockres->l_level = lockres->l_requested;
+	lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED);
+	lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+
+	mlog_exit_void();
+}
+
+static void ocfs2_inode_ast_func(void *opaque)
+{
+	struct ocfs2_lock_res *lockres = opaque;
+	struct inode *inode;
+	struct dlm_lockstatus *lksb;
+	unsigned long flags;
+
+	mlog_entry_void();
+
+	inode = ocfs2_lock_res_inode(lockres);
+
+	mlog(0, "AST fired for inode %"MLFu64", l_action = %u, type = %s\n",
+	     OCFS2_I(inode)->ip_blkno, lockres->l_action,
+	     ocfs2_lock_type_string(lockres->l_type));
+
+	BUG_ON(!ocfs2_is_inode_lock(lockres));
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+
+	lksb = &(lockres->l_lksb);
+	if (lksb->status != DLM_NORMAL) {
+		mlog(ML_ERROR, "ocfs2_inode_ast_func: lksb status value of %u "
+		     "on inode %"MLFu64"\n", lksb->status,
+		     OCFS2_I(inode)->ip_blkno);
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		mlog_exit_void();
+		return;
+	}
+
+	switch(lockres->l_action) {
+	case OCFS2_AST_ATTACH:
+		ocfs2_generic_handle_attach_action(lockres);
+		lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL);
+		break;
+	case OCFS2_AST_CONVERT:
+		ocfs2_generic_handle_convert_action(lockres);
+		break;
+	case OCFS2_AST_DOWNCONVERT:
+		ocfs2_generic_handle_downconvert_action(lockres);
+		break;
+	default:
+		mlog(ML_ERROR, "lockres %s: ast fired with invalid action: %u "
+		     "lockres flags = 0x%lx, unlock action: %u\n",
+		     lockres->l_name, lockres->l_action, lockres->l_flags,
+		     lockres->l_unlock_action);
+
+		BUG();
+	}
+
+	/* data and rw locking ignores refresh flag for now. */
+	if (lockres->l_type != OCFS2_LOCK_TYPE_META)
+		lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
+
+	/* set it to something invalid so if we get called again we
+	 * can catch it. */
+	lockres->l_action = OCFS2_AST_INVALID;
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+	wake_up(&lockres->l_event);
+
+	mlog_exit_void();
+}
+
+static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
+				     int level)
+{
+	int needs_downconvert = 0;
+	mlog_entry_void();
+
+	assert_spin_locked(&lockres->l_lock);
+
+	lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
+
+	if (level > lockres->l_blocking) {
+		/* only schedule a downconvert if we haven't already scheduled
+		 * one that goes low enough to satisfy the level we're
+		 * blocking.  this also catches the case where we get
+		 * duplicate BASTs */
+		if (ocfs2_highest_compat_lock_level(level) <
+		    ocfs2_highest_compat_lock_level(lockres->l_blocking))
+			needs_downconvert = 1;
+
+		lockres->l_blocking = level;
+	}
+
+	mlog_exit(needs_downconvert);
+	return needs_downconvert;
+}
+
+static void ocfs2_generic_bast_func(struct ocfs2_super *osb,
+				    struct ocfs2_lock_res *lockres,
+				    int level)
+{
+	int needs_downconvert;
+	unsigned long flags;
+
+	mlog_entry_void();
+
+	BUG_ON(level <= LKM_NLMODE);
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
+	if (needs_downconvert)
+		ocfs2_schedule_blocked_lock(osb, lockres);
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	ocfs2_kick_vote_thread(osb);
+
+	wake_up(&lockres->l_event);
+	mlog_exit_void();
+}
+
+static void ocfs2_inode_bast_func(void *opaque, int level)
+{
+	struct ocfs2_lock_res *lockres = opaque;
+	struct inode *inode;
+	struct ocfs2_super *osb;
+
+	mlog_entry_void();
+
+	BUG_ON(!ocfs2_is_inode_lock(lockres));
+
+	inode = ocfs2_lock_res_inode(lockres);
+	osb = OCFS2_SB(inode->i_sb);
+
+	mlog(0, "BAST fired for inode %"MLFu64", blocking = %d, level = %d "
+	     "type = %s\n", OCFS2_I(inode)->ip_blkno, level,
+	     lockres->l_level,
+	     ocfs2_lock_type_string(lockres->l_type));
+
+	ocfs2_generic_bast_func(osb, lockres, level);
+
+	mlog_exit_void();
+}
+
+static void ocfs2_generic_ast_func(struct ocfs2_lock_res *lockres,
+				   int ignore_refresh)
+{
+	struct dlm_lockstatus *lksb = &lockres->l_lksb;
+	unsigned long flags;
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+
+	if (lksb->status != DLM_NORMAL) {
+		mlog(ML_ERROR, "lockres %s: lksb status value of %u!\n",
+		     lockres->l_name, lksb->status);
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		return;
+	}
+
+	switch(lockres->l_action) {
+	case OCFS2_AST_ATTACH:
+		ocfs2_generic_handle_attach_action(lockres);
+		break;
+	case OCFS2_AST_CONVERT:
+		ocfs2_generic_handle_convert_action(lockres);
+		break;
+	case OCFS2_AST_DOWNCONVERT:
+		ocfs2_generic_handle_downconvert_action(lockres);
+		break;
+	default:
+		BUG();
+	}
+
+	if (ignore_refresh)
+		lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
+
+	/* set it to something invalid so if we get called again we
+	 * can catch it. */
+	lockres->l_action = OCFS2_AST_INVALID;
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	wake_up(&lockres->l_event);
+}
+
+static void ocfs2_super_ast_func(void *opaque)
+{
+	struct ocfs2_lock_res *lockres = opaque;
+
+	mlog_entry_void();
+	mlog(0, "Superblock AST fired\n");
+
+	BUG_ON(!ocfs2_is_super_lock(lockres));
+	ocfs2_generic_ast_func(lockres, 0);
+
+	mlog_exit_void();
+}
+
+static void ocfs2_super_bast_func(void *opaque,
+				  int level)
+{
+	struct ocfs2_lock_res *lockres = opaque;
+	struct ocfs2_super *osb;
+
+	mlog_entry_void();
+	mlog(0, "Superblock BAST fired\n");
+
+	BUG_ON(!ocfs2_is_super_lock(lockres));
+       	osb = ocfs2_lock_res_super(lockres);
+	ocfs2_generic_bast_func(osb, lockres, level);
+
+	mlog_exit_void();
+}
+
+static void ocfs2_rename_ast_func(void *opaque)
+{
+	struct ocfs2_lock_res *lockres = opaque;
+
+	mlog_entry_void();
+
+	mlog(0, "Rename AST fired\n");
+
+	BUG_ON(!ocfs2_is_rename_lock(lockres));
+
+	ocfs2_generic_ast_func(lockres, 1);
+
+	mlog_exit_void();
+}
+
+static void ocfs2_rename_bast_func(void *opaque,
+				   int level)
+{
+	struct ocfs2_lock_res *lockres = opaque;
+	struct ocfs2_super *osb;
+
+	mlog_entry_void();
+
+	mlog(0, "Rename BAST fired\n");
+
+	BUG_ON(!ocfs2_is_rename_lock(lockres));
+
+	osb = ocfs2_lock_res_super(lockres);
+	ocfs2_generic_bast_func(osb, lockres, level);
+
+	mlog_exit_void();
+}
+
+static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
+						int convert)
+{
+	unsigned long flags;
+
+	mlog_entry_void();
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+	if (convert)
+		lockres->l_action = OCFS2_AST_INVALID;
+	else
+		lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	wake_up(&lockres->l_event);
+	mlog_exit_void();
+}
+
+/* Note: If we detect another process working on the lock (i.e.,
+ * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller
+ * to do the right thing in that case.
+ */
+static int ocfs2_lock_create(struct ocfs2_super *osb,
+			     struct ocfs2_lock_res *lockres,
+			     int level,
+			     int dlm_flags)
+{
+	int ret = 0;
+	enum dlm_status status;
+	unsigned long flags;
+
+	mlog_entry_void();
+
+	mlog(0, "lock %s, level = %d, flags = %d\n", lockres->l_name, level,
+	     dlm_flags);
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) ||
+	    (lockres->l_flags & OCFS2_LOCK_BUSY)) {
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		goto bail;
+	}
+
+	lockres->l_action = OCFS2_AST_ATTACH;
+	lockres->l_requested = level;
+	lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	status = dlmlock(osb->dlm,
+			 level,
+			 &lockres->l_lksb,
+			 dlm_flags,
+			 lockres->l_name,
+			 lockres->l_ops->ast,
+			 lockres,
+			 lockres->l_ops->bast);
+	if (status != DLM_NORMAL) {
+		ocfs2_log_dlm_error("dlmlock", status, lockres);
+		ret = -EINVAL;
+		ocfs2_recover_from_dlm_error(lockres, 1);
+	}
+
+	mlog(0, "lock %s, successfull return from dlmlock\n", lockres->l_name);
+
+bail:
+	mlog_exit(ret);
+	return ret;
+}
+
+static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres,
+					int flag)
+{
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	ret = lockres->l_flags & flag;
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	return ret;
+}
+
+static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres)
+
+{
+	wait_event(lockres->l_event,
+		   !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY));
+}
+
+static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres)
+
+{
+	wait_event(lockres->l_event,
+		   !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING));
+}
+
+/* predict what lock level we'll be dropping down to on behalf
+ * of another node, and return true if the currently wanted
+ * level will be compatible with it. */
+static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
+						     int wanted)
+{
+	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
+
+	return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking);
+}
+
+static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
+{
+	INIT_LIST_HEAD(&mw->mw_item);
+	init_completion(&mw->mw_complete);
+}
+
+static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
+{
+	wait_for_completion(&mw->mw_complete);
+	/* Re-arm the completion in case we want to wait on it again */
+	INIT_COMPLETION(mw->mw_complete);
+	return mw->mw_status;
+}
+
+static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres,
+				    struct ocfs2_mask_waiter *mw,
+				    unsigned long mask,
+				    unsigned long goal)
+{
+	BUG_ON(!list_empty(&mw->mw_item));
+
+	assert_spin_locked(&lockres->l_lock);
+
+	list_add_tail(&mw->mw_item, &lockres->l_mask_waiters);
+	mw->mw_mask = mask;
+	mw->mw_goal = goal;
+}
+
+/* returns 0 if the mw that was removed was already satisfied, -EBUSY
+ * if the mask still hadn't reached its goal */
+static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
+				      struct ocfs2_mask_waiter *mw)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	if (!list_empty(&mw->mw_item)) {
+		if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
+			ret = -EBUSY;
+
+		list_del_init(&mw->mw_item);
+		init_completion(&mw->mw_complete);
+	}
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	return ret;
+
+}
+
+static int ocfs2_cluster_lock(struct ocfs2_super *osb,
+			      struct ocfs2_lock_res *lockres,
+			      int level,
+			      int lkm_flags,
+			      int arg_flags)
+{
+	struct ocfs2_mask_waiter mw;
+	enum dlm_status status;
+	int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR);
+	int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */
+	unsigned long flags;
+
+	mlog_entry_void();
+
+	ocfs2_init_mask_waiter(&mw);
+
+again:
+	wait = 0;
+
+	if (catch_signals && signal_pending(current)) {
+		ret = -ERESTARTSYS;
+		goto out;
+	}
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+
+	mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING,
+			"Cluster lock called on freeing lockres %s! flags "
+			"0x%lx\n", lockres->l_name, lockres->l_flags);
+
+	/* We only compare against the currently granted level
+	 * here. If the lock is blocked waiting on a downconvert,
+	 * we'll get caught below. */
+	if (lockres->l_flags & OCFS2_LOCK_BUSY &&
+	    level > lockres->l_level) {
+		/* is someone sitting in dlm_lock? If so, wait on
+		 * them. */
+		lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+		wait = 1;
+		goto unlock;
+	}
+
+	if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
+		/* lock has not been created yet. */
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+		ret = ocfs2_lock_create(osb, lockres, LKM_NLMODE, 0);
+		if (ret < 0) {
+			mlog_errno(ret);
+			goto out;
+		}
+		goto again;
+	}
+
+	if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
+	    !ocfs2_may_continue_on_blocked_lock(lockres, level)) {
+		/* is the lock is currently blocked on behalf of
+		 * another node */
+		lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0);
+		wait = 1;
+		goto unlock;
+	}
+
+	if (level > lockres->l_level) {
+		if (lockres->l_action != OCFS2_AST_INVALID)
+			mlog(ML_ERROR, "lockres %s has action %u pending\n",
+			     lockres->l_name, lockres->l_action);
+
+		lockres->l_action = OCFS2_AST_CONVERT;
+		lockres->l_requested = level;
+		lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+		BUG_ON(level == LKM_IVMODE);
+		BUG_ON(level == LKM_NLMODE);
+
+		mlog(0, "lock %s, convert from %d to level = %d\n",
+		     lockres->l_name, lockres->l_level, level);
+
+		/* call dlm_lock to upgrade lock now */
+		status = dlmlock(osb->dlm,
+				 level,
+				 &lockres->l_lksb,
+				 lkm_flags|LKM_CONVERT|LKM_VALBLK,
+				 lockres->l_name,
+				 lockres->l_ops->ast,
+				 lockres,
+				 lockres->l_ops->bast);
+		if (status != DLM_NORMAL) {
+			if ((lkm_flags & LKM_NOQUEUE) &&
+			    (status == DLM_NOTQUEUED))
+				ret = -EAGAIN;
+			else {
+				ocfs2_log_dlm_error("dlmlock", status,
+						    lockres);
+				ret = -EINVAL;
+			}
+			ocfs2_recover_from_dlm_error(lockres, 1);
+			goto out;
+		}
+
+		mlog(0, "lock %s, successfull return from dlmlock\n",
+		     lockres->l_name);
+
+		/* At this point we've gone inside the dlm and need to
+		 * complete our work regardless. */
+		catch_signals = 0;
+
+		/* wait for busy to clear and carry on */
+		goto again;
+	}
+
+	/* Ok, if we get here then we're good to go. */
+	ocfs2_inc_holders(lockres, level);
+
+	ret = 0;
+unlock:
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+out:
+	/*
+	 * This is helping work around a lock inversion between the page lock
+	 * and dlm locks.  One path holds the page lock while calling aops
+	 * which block acquiring dlm locks.  The voting thread holds dlm
+	 * locks while acquiring page locks while down converting data locks.
+	 * This block is helping an aop path notice the inversion and back
+	 * off to unlock its page lock before trying the dlm lock again.
+	 */
+	if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
+	    mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) {
+		wait = 0;
+		if (lockres_remove_mask_waiter(lockres, &mw))
+			ret = -EAGAIN;
+		else
+			goto again;
+	}
+	if (wait) {
+		ret = ocfs2_wait_for_mask(&mw);
+		if (ret == 0)
+			goto again;
+		mlog_errno(ret);
+	}
+
+	mlog_exit(ret);
+	return ret;
+}
+
+static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
+				 struct ocfs2_lock_res *lockres,
+				 int level)
+{
+	unsigned long flags;
+
+	mlog_entry_void();
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	ocfs2_dec_holders(lockres, level);
+	ocfs2_vote_on_unlock(osb, lockres);
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+	mlog_exit_void();
+}
+
+static int ocfs2_create_new_inode_lock(struct inode *inode,
+				       struct ocfs2_lock_res *lockres)
+{
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	unsigned long flags;
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
+	lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	return ocfs2_lock_create(osb, lockres, LKM_EXMODE, LKM_LOCAL);
+}
+
+/* Grants us an EX lock on the data and metadata resources, skipping
+ * the normal cluster directory lookup. Use this ONLY on newly created
+ * inodes which other nodes can't possibly see, and which haven't been
+ * hashed in the inode hash yet. This can give us a good performance
+ * increase as it'll skip the network broadcast normally associated
+ * with creating a new lock resource. */
+int ocfs2_create_new_inode_locks(struct inode *inode)
+{
+	int ret;
+
+	BUG_ON(!inode);
+	BUG_ON(!ocfs2_inode_is_new(inode));
+
+	mlog_entry_void();
+
+	mlog(0, "Inode %"MLFu64"\n", OCFS2_I(inode)->ip_blkno);
+
+	/* NOTE: That we don't increment any of the holder counts, nor
+	 * do we add anything to a journal handle. Since this is
+	 * supposed to be a new inode which the cluster doesn't know
+	 * about yet, there is no need to.  As far as the LVB handling
+	 * is concerned, this is basically like acquiring an EX lock
+	 * on a resource which has an invalid one -- we'll set it
+	 * valid when we release the EX. */
+
+	ret = ocfs2_create_new_inode_lock(inode,
+					  &OCFS2_I(inode)->ip_rw_lockres);
+	if (ret) {
+		mlog_errno(ret);
+		goto bail;
+	}
+
+	ret = ocfs2_create_new_inode_lock(inode,
+					  &OCFS2_I(inode)->ip_meta_lockres);
+	if (ret) {
+		mlog_errno(ret);
+		goto bail;
+	}
+
+	ret = ocfs2_create_new_inode_lock(inode,
+					  &OCFS2_I(inode)->ip_data_lockres);
+	if (ret) {
+		mlog_errno(ret);
+		goto bail;
+	}
+
+bail:
+	mlog_exit(ret);
+	return ret;
+}
+
+int ocfs2_rw_lock(struct inode *inode, int write)
+{
+	int status, level;
+	struct ocfs2_lock_res *lockres;
+
+	BUG_ON(!inode);
+
+	mlog_entry_void();
+
+	mlog(0, "inode %"MLFu64" take %s RW lock\n",
+	     OCFS2_I(inode)->ip_blkno,
+	     write ? "EXMODE" : "PRMODE");
+
+	lockres = &OCFS2_I(inode)->ip_rw_lockres;
+
+	level = write ? LKM_EXMODE : LKM_PRMODE;
+
+	status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 0,
+				    0);
+	if (status < 0)
+		mlog_errno(status);
+
+	mlog_exit(status);
+	return status;
+}
+
+void ocfs2_rw_unlock(struct inode *inode, int write)
+{
+	int level = write ? LKM_EXMODE : LKM_PRMODE;
+	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;
+
+	mlog_entry_void();
+
+	mlog(0, "inode %"MLFu64" drop %s RW lock\n",
+	     OCFS2_I(inode)->ip_blkno,
+	     write ? "EXMODE" : "PRMODE");
+
+	ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
+
+	mlog_exit_void();
+}
+
+int ocfs2_data_lock_full(struct inode *inode,
+			 int write,
+			 int arg_flags)
+{
+	int status = 0, level;
+	struct ocfs2_lock_res *lockres;
+
+	BUG_ON(!inode);
+
+	mlog_entry_void();
+
+	mlog(0, "inode %"MLFu64" take %s DATA lock\n",
+	     OCFS2_I(inode)->ip_blkno,
+	     write ? "EXMODE" : "PRMODE");
+
+	/* We'll allow faking a readonly data lock for
+	 * rodevices. */
+	if (ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb))) {
+		if (write) {
+			status = -EROFS;
+			mlog_errno(status);
+		}
+		goto out;
+	}
+
+	lockres = &OCFS2_I(inode)->ip_data_lockres;
+
+	level = write ? LKM_EXMODE : LKM_PRMODE;
+
+	status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level,
+				    0, arg_flags);
+	if (status < 0 && status != -EAGAIN)
+		mlog_errno(status);
+
+out:
+	mlog_exit(status);
+	return status;
+}
+
+/* see ocfs2_meta_lock_with_page() */
+int ocfs2_data_lock_with_page(struct inode *inode,
+			      int write,
+			      struct page *page)
+{
+	int ret;
+
+	ret = ocfs2_data_lock_full(inode, write, OCFS2_LOCK_NONBLOCK);
+	if (ret == -EAGAIN) {
+		unlock_page(page);
+		if (ocfs2_data_lock(inode, write) == 0)
+			ocfs2_data_unlock(inode, write);
+		ret = AOP_TRUNCATED_PAGE;
+	}
+
+	return ret;
+}
+
+static void ocfs2_vote_on_unlock(struct ocfs2_super *osb,
+				 struct ocfs2_lock_res *lockres)
+{
+	int kick = 0;
+
+	mlog_entry_void();
+
+	/* If we know that another node is waiting on our lock, kick
+	 * the vote thread * pre-emptively when we reach a release
+	 * condition. */
+	if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
+		switch(lockres->l_blocking) {
+		case LKM_EXMODE:
+			if (!lockres->l_ex_holders && !lockres->l_ro_holders)
+				kick = 1;
+			break;
+		case LKM_PRMODE:
+			if (!lockres->l_ex_holders)
+				kick = 1;
+			break;
+		default:
+			BUG();
+		}
+	}
+
+	if (kick)
+		ocfs2_kick_vote_thread(osb);
+
+	mlog_exit_void();
+}
+
+void ocfs2_data_unlock(struct inode *inode,
+		       int write)
+{
+	int level = write ? LKM_EXMODE : LKM_PRMODE;
+	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_data_lockres;
+
+	mlog_entry_void();
+
+	mlog(0, "inode %"MLFu64" drop %s DATA lock\n",
+	     OCFS2_I(inode)->ip_blkno,
+	     write ? "EXMODE" : "PRMODE");
+
+	if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)))
+		ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
+
+	mlog_exit_void();
+}
+
+#define OCFS2_SEC_BITS   34
+#define OCFS2_SEC_SHIFT  (64 - 34)
+#define OCFS2_NSEC_MASK  ((1ULL << OCFS2_SEC_SHIFT) - 1)
+
+/* LVB only has room for 64 bits of time here so we pack it for
+ * now. */
+static u64 ocfs2_pack_timespec(struct timespec *spec)
+{
+	u64 res;
+	u64 sec = spec->tv_sec;
+	u32 nsec = spec->tv_nsec;
+
+	res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);
+
+	return res;
+}
+
+/* Call this with the lockres locked. I am reasonably sure we don't
+ * need ip_lock in this function as anyone who would be changing those
+ * values is supposed to be blocked in ocfs2_meta_lock right now. */
+static void __ocfs2_stuff_meta_lvb(struct inode *inode)
+{
+	struct ocfs2_inode_info *oi = OCFS2_I(inode);
+	struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
+	struct ocfs2_meta_lvb *lvb;
+
+	mlog_entry_void();
+
+	lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
+
+	lvb->lvb_version   = cpu_to_be32(OCFS2_LVB_VERSION);
+	lvb->lvb_isize	   = cpu_to_be64(i_size_read(inode));
+	lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
+	lvb->lvb_iuid      = cpu_to_be32(inode->i_uid);
+	lvb->lvb_igid      = cpu_to_be32(inode->i_gid);
+	lvb->lvb_imode     = cpu_to_be16(inode->i_mode);
+	lvb->lvb_inlink    = cpu_to_be16(inode->i_nlink);
+	lvb->lvb_iatime_packed  =
+		cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
+	lvb->lvb_ictime_packed =
+		cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
+	lvb->lvb_imtime_packed =
+		cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
+
+	mlog_meta_lvb(0, lockres);
+
+	mlog_exit_void();
+}
+
+static void ocfs2_unpack_timespec(struct timespec *spec,
+				  u64 packed_time)
+{
+	spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
+	spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
+}
+
+static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
+{
+	struct ocfs2_inode_info *oi = OCFS2_I(inode);
+	struct ocfs2_lock_res *lockres = &oi->ip_meta_lockres;
+	struct ocfs2_meta_lvb *lvb;
+
+	mlog_entry_void();
+
+	mlog_meta_lvb(0, lockres);
+
+	lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
+
+	/* We're safe here without the lockres lock... */
+	spin_lock(&oi->ip_lock);
+	oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
+	i_size_write(inode, be64_to_cpu(lvb->lvb_isize));
+
+	/* fast-symlinks are a special case */
+	if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
+		inode->i_blocks = 0;
+	else
+		inode->i_blocks =
+			ocfs2_align_bytes_to_sectors(i_size_read(inode));
+
+	inode->i_uid     = be32_to_cpu(lvb->lvb_iuid);
+	inode->i_gid     = be32_to_cpu(lvb->lvb_igid);
+	inode->i_mode    = be16_to_cpu(lvb->lvb_imode);
+	inode->i_nlink   = be16_to_cpu(lvb->lvb_inlink);
+	ocfs2_unpack_timespec(&inode->i_atime,
+			      be64_to_cpu(lvb->lvb_iatime_packed));
+	ocfs2_unpack_timespec(&inode->i_mtime,
+			      be64_to_cpu(lvb->lvb_imtime_packed));
+	ocfs2_unpack_timespec(&inode->i_ctime,
+			      be64_to_cpu(lvb->lvb_ictime_packed));
+	spin_unlock(&oi->ip_lock);
+
+	mlog_exit_void();
+}
+
+static inline int ocfs2_meta_lvb_is_trustable(struct ocfs2_lock_res *lockres)
+{
+	struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
+
+	if (be32_to_cpu(lvb->lvb_version) == OCFS2_LVB_VERSION)
+		return 1;
+	return 0;
+}
+
+/* Determine whether a lock resource needs to be refreshed, and
+ * arbitrate who gets to refresh it.
+ *
+ *   0 means no refresh needed.
+ *
+ *   > 0 means you need to refresh this and you MUST call
+ *   ocfs2_complete_lock_res_refresh afterwards. */
+static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
+{
+	unsigned long flags;
+	int status = 0;
+
+	mlog_entry_void();
+
+refresh_check:
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		goto bail;
+	}
+
+	if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+		ocfs2_wait_on_refreshing_lock(lockres);
+		goto refresh_check;
+	}
+
+	/* Ok, I'll be the one to refresh this lock. */
+	lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	status = 1;
+bail:
+	mlog_exit(status);
+	return status;
+}
+
+/* If status is non zero, I'll mark it as not being in refresh
+ * anymroe, but i won't clear the needs refresh flag. */
+static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
+						   int status)
+{
+	unsigned long flags;
+	mlog_entry_void();
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
+	if (!status)
+		lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	wake_up(&lockres->l_event);
+
+	mlog_exit_void();
+}
+
+/* may or may not return a bh if it went to disk. */
+static int ocfs2_meta_lock_update(struct inode *inode,
+				  struct buffer_head **bh)
+{
+	int status = 0;
+	struct ocfs2_inode_info *oi = OCFS2_I(inode);
+	struct ocfs2_lock_res *lockres;
+	struct ocfs2_dinode *fe;
+
+	mlog_entry_void();
+
+	spin_lock(&oi->ip_lock);
+	if (oi->ip_flags & OCFS2_INODE_DELETED) {
+		mlog(0, "Orphaned inode %"MLFu64" was deleted while we "
+		     "were waiting on a lock. ip_flags = 0x%x\n",
+		     oi->ip_blkno, oi->ip_flags);
+		spin_unlock(&oi->ip_lock);
+		status = -ENOENT;
+		goto bail;
+	}
+	spin_unlock(&oi->ip_lock);
+
+	lockres = &oi->ip_meta_lockres;
+
+	if (!ocfs2_should_refresh_lock_res(lockres))
+		goto bail;
+
+	/* This will discard any caching information we might have had
+	 * for the inode metadata. */
+	ocfs2_metadata_cache_purge(inode);
+
+	/* will do nothing for inode types that don't use the extent
+	 * map (directories, bitmap files, etc) */
+	ocfs2_extent_map_trunc(inode, 0);
+
+	if (ocfs2_meta_lvb_is_trustable(lockres)) {
+		mlog(0, "Trusting LVB on inode %"MLFu64"\n",
+		     oi->ip_blkno);
+		ocfs2_refresh_inode_from_lvb(inode);
+	} else {
+		/* Boo, we have to go to disk. */
+		/* read bh, cast, ocfs2_refresh_inode */
+		status = ocfs2_read_block(OCFS2_SB(inode->i_sb), oi->ip_blkno,
+					  bh, OCFS2_BH_CACHED, inode);
+		if (status < 0) {
+			mlog_errno(status);
+			goto bail_refresh;
+		}
+		fe = (struct ocfs2_dinode *) (*bh)->b_data;
+
+		/* This is a good chance to make sure we're not
+		 * locking an invalid object.
+		 *
+		 * We bug on a stale inode here because we checked
+		 * above whether it was wiped from disk. The wiping
+		 * node provides a guarantee that we receive that
+		 * message and can mark the inode before dropping any
+		 * locks associated with it. */
+		if (!OCFS2_IS_VALID_DINODE(fe)) {
+			OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
+			status = -EIO;
+			goto bail_refresh;
+		}
+		mlog_bug_on_msg(inode->i_generation !=
+				le32_to_cpu(fe->i_generation),
+				"Invalid dinode %"MLFu64" disk generation: %u "
+				"inode->i_generation: %u\n",
+				oi->ip_blkno, le32_to_cpu(fe->i_generation),
+				inode->i_generation);
+		mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
+				!(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
+				"Stale dinode %"MLFu64" dtime: %"MLFu64" "
+				"flags: 0x%x\n", oi->ip_blkno,
+				le64_to_cpu(fe->i_dtime),
+				le32_to_cpu(fe->i_flags));
+
+		ocfs2_refresh_inode(inode, fe);
+	}
+
+	status = 0;
+bail_refresh:
+	ocfs2_complete_lock_res_refresh(lockres, status);
+bail:
+	mlog_exit(status);
+	return status;
+}
+
+static int ocfs2_assign_bh(struct inode *inode,
+			   struct buffer_head **ret_bh,
+			   struct buffer_head *passed_bh)
+{
+	int status;
+
+	if (passed_bh) {
+		/* Ok, the update went to disk for us, use the
+		 * returned bh. */
+		*ret_bh = passed_bh;
+		get_bh(*ret_bh);
+
+		return 0;
+	}
+
+	status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
+				  OCFS2_I(inode)->ip_blkno,
+				  ret_bh,
+				  OCFS2_BH_CACHED,
+				  inode);
+	if (status < 0)
+		mlog_errno(status);
+
+	return status;
+}
+
+/*
+ * returns < 0 error if the callback will never be called, otherwise
+ * the result of the lock will be communicated via the callback.
+ */
+int ocfs2_meta_lock_full(struct inode *inode,
+			 struct ocfs2_journal_handle *handle,
+			 struct buffer_head **ret_bh,
+			 int ex,
+			 int arg_flags)
+{
+	int status, level, dlm_flags, acquired;
+	struct ocfs2_lock_res *lockres;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	struct buffer_head *local_bh = NULL;
+
+	BUG_ON(!inode);
+
+	mlog_entry_void();
+
+	mlog(0, "inode %"MLFu64", take %s META lock\n",
+	     OCFS2_I(inode)->ip_blkno,
+	     ex ? "EXMODE" : "PRMODE");
+
+	status = 0;
+	acquired = 0;
+	/* We'll allow faking a readonly metadata lock for
+	 * rodevices. */
+	if (ocfs2_is_hard_readonly(osb)) {
+		if (ex)
+			status = -EROFS;
+		goto bail;
+	}
+
+	if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
+		wait_event(osb->recovery_event,
+			   ocfs2_node_map_is_empty(osb, &osb->recovery_map));
+
+	acquired = 0;
+	lockres = &OCFS2_I(inode)->ip_meta_lockres;
+	level = ex ? LKM_EXMODE : LKM_PRMODE;
+	dlm_flags = 0;
+	if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
+		dlm_flags |= LKM_NOQUEUE;
+
+	status = ocfs2_cluster_lock(osb, lockres, level, dlm_flags, arg_flags);
+	if (status < 0) {
+		if (status != -EAGAIN && status != -EIOCBRETRY)
+			mlog_errno(status);
+		goto bail;
+	}
+
+	/* Notify the error cleanup path to drop the cluster lock. */
+	acquired = 1;
+
+	/* We wait twice because a node may have died while we were in
+	 * the lower dlm layers. The second time though, we've
+	 * committed to owning this lock so we don't allow signals to
+	 * abort the operation. */
+	if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
+		wait_event(osb->recovery_event,
+			   ocfs2_node_map_is_empty(osb, &osb->recovery_map));
+
+	/* This is fun. The caller may want a bh back, or it may
+	 * not. ocfs2_meta_lock_update definitely wants one in, but
+	 * may or may not read one, depending on what's in the
+	 * LVB. The result of all of this is that we've *only* gone to
+	 * disk if we have to, so the complexity is worthwhile. */
+	status = ocfs2_meta_lock_update(inode, &local_bh);
+	if (status < 0) {
+		if (status != -ENOENT)
+			mlog_errno(status);
+		goto bail;
+	}
+
+	if (ret_bh) {
+		status = ocfs2_assign_bh(inode, ret_bh, local_bh);
+		if (status < 0) {
+			mlog_errno(status);
+			goto bail;
+		}
+	}
+
+	if (handle) {
+		status = ocfs2_handle_add_lock(handle, inode);
+		if (status < 0)
+			mlog_errno(status);
+	}
+
+bail:
+	if (status < 0) {
+		if (ret_bh && (*ret_bh)) {
+			brelse(*ret_bh);
+			*ret_bh = NULL;
+		}
+		if (acquired)
+			ocfs2_meta_unlock(inode, ex);
+	}
+
+	if (local_bh)
+		brelse(local_bh);
+
+	mlog_exit(status);
+	return status;
+}
+
+/*
+ * This is working around a lock inversion between tasks acquiring DLM locks
+ * while holding a page lock and the vote thread which blocks dlm lock acquiry
+ * while acquiring page locks.
+ *
+ * ** These _with_page variantes are only intended to be called from aop
+ * methods that hold page locks and return a very specific *positive* error
+ * code that aop methods pass up to the VFS -- test for errors with != 0. **
+ *
+ * The DLM is called such that it returns -EAGAIN if it would have blocked
+ * waiting for the vote thread.  In that case we unlock our page so the vote
+ * thread can make progress.  Once we've done this we have to return
+ * AOP_TRUNCATED_PAGE so the aop method that called us can bubble that back up
+ * into the VFS who will then immediately retry the aop call.
+ *
+ * We do a blocking lock and immediate unlock before returning, though, so that
+ * the lock has a great chance of being cached on this node by the time the VFS
+ * calls back to retry the aop.    This has a potential to livelock as nodes
+ * ping locks back and forth, but that's a risk we're willing to take to avoid
+ * the lock inversion simply.
+ */
+int ocfs2_meta_lock_with_page(struct inode *inode,
+			      struct ocfs2_journal_handle *handle,
+			      struct buffer_head **ret_bh,
+			      int ex,
+			      struct page *page)
+{
+	int ret;
+
+	ret = ocfs2_meta_lock_full(inode, handle, ret_bh, ex,
+				   OCFS2_LOCK_NONBLOCK);
+	if (ret == -EAGAIN) {
+		unlock_page(page);
+		if (ocfs2_meta_lock(inode, handle, ret_bh, ex) == 0)
+			ocfs2_meta_unlock(inode, ex);
+		ret = AOP_TRUNCATED_PAGE;
+	}
+
+	return ret;
+}
+
+void ocfs2_meta_unlock(struct inode *inode,
+		       int ex)
+{
+	int level = ex ? LKM_EXMODE : LKM_PRMODE;
+	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres;
+
+	mlog_entry_void();
+
+	mlog(0, "inode %"MLFu64" drop %s META lock\n",
+	     OCFS2_I(inode)->ip_blkno,
+	     ex ? "EXMODE" : "PRMODE");
+
+	if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)))
+		ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
+
+	mlog_exit_void();
+}
+
+int ocfs2_super_lock(struct ocfs2_super *osb,
+		     int ex)
+{
+	int status;
+	int level = ex ? LKM_EXMODE : LKM_PRMODE;
+	struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
+	struct buffer_head *bh;
+	struct ocfs2_slot_info *si = osb->slot_info;
+
+	mlog_entry_void();
+
+	if (ocfs2_is_hard_readonly(osb))
+		return -EROFS;
+
+	status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
+	if (status < 0) {
+		mlog_errno(status);
+		goto bail;
+	}
+
+	/* The super block lock path is really in the best position to
+	 * know when resources covered by the lock need to be
+	 * refreshed, so we do it here. Of course, making sense of
+	 * everything is up to the caller :) */
+	status = ocfs2_should_refresh_lock_res(lockres);
+	if (status < 0) {
+		mlog_errno(status);
+		goto bail;
+	}
+	if (status) {
+		bh = si->si_bh;
+		status = ocfs2_read_block(osb, bh->b_blocknr, &bh, 0,
+					  si->si_inode);
+		if (status == 0)
+			ocfs2_update_slot_info(si);
+
+		ocfs2_complete_lock_res_refresh(lockres, status);
+
+		if (status < 0)
+			mlog_errno(status);
+	}
+bail:
+	mlog_exit(status);
+	return status;
+}
+
+void ocfs2_super_unlock(struct ocfs2_super *osb,
+			int ex)
+{
+	int level = ex ? LKM_EXMODE : LKM_PRMODE;
+	struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
+
+	ocfs2_cluster_unlock(osb, lockres, level);
+}
+
+int ocfs2_rename_lock(struct ocfs2_super *osb)
+{
+	int status;
+	struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
+
+	if (ocfs2_is_hard_readonly(osb))
+		return -EROFS;
+
+	status = ocfs2_cluster_lock(osb, lockres, LKM_EXMODE, 0, 0);
+	if (status < 0)
+		mlog_errno(status);
+
+	return status;
+}
+
+void ocfs2_rename_unlock(struct ocfs2_super *osb)
+{
+	struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
+
+	ocfs2_cluster_unlock(osb, lockres, LKM_EXMODE);
+}
+
+/* Reference counting of the dlm debug structure. We want this because
+ * open references on the debug inodes can live on after a mount, so
+ * we can't rely on the ocfs2_super to always exist. */
+static void ocfs2_dlm_debug_free(struct kref *kref)
+{
+	struct ocfs2_dlm_debug *dlm_debug;
+
+	dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);
+
+	kfree(dlm_debug);
+}
+
+void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
+{
+	if (dlm_debug)
+		kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
+}
+
+static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
+{
+	kref_get(&debug->d_refcnt);
+}
+
+struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
+{
+	struct ocfs2_dlm_debug *dlm_debug;
+
+	dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
+	if (!dlm_debug) {
+		mlog_errno(-ENOMEM);
+		goto out;
+	}
+
+	kref_init(&dlm_debug->d_refcnt);
+	INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
+	dlm_debug->d_locking_state = NULL;
+out:
+	return dlm_debug;
+}
+
+/* Access to this is arbitrated for us via seq_file->sem. */
+struct ocfs2_dlm_seq_priv {
+	struct ocfs2_dlm_debug *p_dlm_debug;
+	struct ocfs2_lock_res p_iter_res;
+	struct ocfs2_lock_res p_tmp_res;
+};
+
+static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
+						 struct ocfs2_dlm_seq_priv *priv)
+{
+	struct ocfs2_lock_res *iter, *ret = NULL;
+	struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;
+
+	assert_spin_locked(&ocfs2_dlm_tracking_lock);
+
+	list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
+		/* discover the head of the list */
+		if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
+			mlog(0, "End of list found, %p\n", ret);
+			break;
+		}
+
+		/* We track our "dummy" iteration lockres' by a NULL
+		 * l_ops field. */
+		if (iter->l_ops != NULL) {
+			ret = iter;
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
+{
+	struct ocfs2_dlm_seq_priv *priv = m->private;
+	struct ocfs2_lock_res *iter;
+
+	spin_lock(&ocfs2_dlm_tracking_lock);
+	iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
+	if (iter) {
+		/* Since lockres' have the lifetime of their container
+		 * (which can be inodes, ocfs2_supers, etc) we want to
+		 * copy this out to a temporary lockres while still
+		 * under the spinlock. Obviously after this we can't
+		 * trust any pointers on the copy returned, but that's
+		 * ok as the information we want isn't typically held
+		 * in them. */
+		priv->p_tmp_res = *iter;
+		iter = &priv->p_tmp_res;
+	}
+	spin_unlock(&ocfs2_dlm_tracking_lock);
+
+	return iter;
+}
+
+static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
+{
+}
+
+static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	struct ocfs2_dlm_seq_priv *priv = m->private;
+	struct ocfs2_lock_res *iter = v;
+	struct ocfs2_lock_res *dummy = &priv->p_iter_res;
+
+	spin_lock(&ocfs2_dlm_tracking_lock);
+	iter = ocfs2_dlm_next_res(iter, priv);
+	list_del_init(&dummy->l_debug_list);
+	if (iter) {
+		list_add(&dummy->l_debug_list, &iter->l_debug_list);
+		priv->p_tmp_res = *iter;
+		iter = &priv->p_tmp_res;
+	}
+	spin_unlock(&ocfs2_dlm_tracking_lock);
+
+	return iter;
+}
+
+/* So that debugfs.ocfs2 can determine which format is being used */
+#define OCFS2_DLM_DEBUG_STR_VERSION 1
+static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
+{
+	int i;
+	char *lvb;
+	struct ocfs2_lock_res *lockres = v;
+
+	if (!lockres)
+		return -EINVAL;
+
+	seq_printf(m, "0x%x\t"
+		   "%.*s\t"
+		   "%d\t"
+		   "0x%lx\t"
+		   "0x%x\t"
+		   "0x%x\t"
+		   "%u\t"
+		   "%u\t"
+		   "%d\t"
+		   "%d\t",
+		   OCFS2_DLM_DEBUG_STR_VERSION,
+		   OCFS2_LOCK_ID_MAX_LEN, lockres->l_name,
+		   lockres->l_level,
+		   lockres->l_flags,
+		   lockres->l_action,
+		   lockres->l_unlock_action,
+		   lockres->l_ro_holders,
+		   lockres->l_ex_holders,
+		   lockres->l_requested,
+		   lockres->l_blocking);
+
+	/* Dump the raw LVB */
+	lvb = lockres->l_lksb.lvb;
+	for(i = 0; i < DLM_LVB_LEN; i++)
+		seq_printf(m, "0x%x\t", lvb[i]);
+
+	/* End the line */
+	seq_printf(m, "\n");
+	return 0;
+}
+
+static struct seq_operations ocfs2_dlm_seq_ops = {
+	.start =	ocfs2_dlm_seq_start,
+	.stop =		ocfs2_dlm_seq_stop,
+	.next =		ocfs2_dlm_seq_next,
+	.show =		ocfs2_dlm_seq_show,
+};
+
+static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq = (struct seq_file *) file->private_data;
+	struct ocfs2_dlm_seq_priv *priv = seq->private;
+	struct ocfs2_lock_res *res = &priv->p_iter_res;
+
+	ocfs2_remove_lockres_tracking(res);
+	ocfs2_put_dlm_debug(priv->p_dlm_debug);
+	return seq_release_private(inode, file);
+}
+
+static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
+{
+	int ret;
+	struct ocfs2_dlm_seq_priv *priv;
+	struct seq_file *seq;
+	struct ocfs2_super *osb;
+
+	priv = kzalloc(sizeof(struct ocfs2_dlm_seq_priv), GFP_KERNEL);
+	if (!priv) {
+		ret = -ENOMEM;
+		mlog_errno(ret);
+		goto out;
+	}
+	osb = (struct ocfs2_super *) inode->u.generic_ip;
+	ocfs2_get_dlm_debug(osb->osb_dlm_debug);
+	priv->p_dlm_debug = osb->osb_dlm_debug;
+	INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);
+
+	ret = seq_open(file, &ocfs2_dlm_seq_ops);
+	if (ret) {
+		kfree(priv);
+		mlog_errno(ret);
+		goto out;
+	}
+
+	seq = (struct seq_file *) file->private_data;
+	seq->private = priv;
+
+	ocfs2_add_lockres_tracking(&priv->p_iter_res,
+				   priv->p_dlm_debug);
+
+out:
+	return ret;
+}
+
+static struct file_operations ocfs2_dlm_debug_fops = {
+	.open =		ocfs2_dlm_debug_open,
+	.release =	ocfs2_dlm_debug_release,
+	.read =		seq_read,
+	.llseek =	seq_lseek,
+};
+
+static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
+{
+	int ret = 0;
+	struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
+
+	dlm_debug->d_locking_state = debugfs_create_file("locking_state",
+							 S_IFREG|S_IRUSR,
+							 osb->osb_debug_root,
+							 osb,
+							 &ocfs2_dlm_debug_fops);
+	if (!dlm_debug->d_locking_state) {
+		ret = -EINVAL;
+		mlog(ML_ERROR,
+		     "Unable to create locking state debugfs file.\n");
+		goto out;
+	}
+
+	ocfs2_get_dlm_debug(dlm_debug);
+out:
+	return ret;
+}
+
+static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
+{
+	struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
+
+	if (dlm_debug) {
+		debugfs_remove(dlm_debug->d_locking_state);
+		ocfs2_put_dlm_debug(dlm_debug);
+	}
+}
+
+int ocfs2_dlm_init(struct ocfs2_super *osb)
+{
+	int status;
+	u32 dlm_key;
+	struct dlm_ctxt *dlm;
+
+	mlog_entry_void();
+
+	status = ocfs2_dlm_init_debug(osb);
+	if (status < 0) {
+		mlog_errno(status);
+		goto bail;
+	}
+
+	/* launch vote thread */
+	osb->vote_task = kthread_run(ocfs2_vote_thread, osb, "ocfs2vote-%d",
+				     osb->osb_id);
+	if (IS_ERR(osb->vote_task)) {
+		status = PTR_ERR(osb->vote_task);
+		osb->vote_task = NULL;
+		mlog_errno(status);
+		goto bail;
+	}
+
+	/* used by the dlm code to make message headers unique, each
+	 * node in this domain must agree on this. */
+	dlm_key = crc32_le(0, osb->uuid_str, strlen(osb->uuid_str));
+
+	/* for now, uuid == domain */
+	dlm = dlm_register_domain(osb->uuid_str, dlm_key);
+	if (IS_ERR(dlm)) {
+		status = PTR_ERR(dlm);
+		mlog_errno(status);
+		goto bail;
+	}
+
+	ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
+	ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
+
+	dlm_register_eviction_cb(dlm, &osb->osb_eviction_cb);
+
+	osb->dlm = dlm;
+
+	status = 0;
+bail:
+	if (status < 0) {
+		ocfs2_dlm_shutdown_debug(osb);
+		if (osb->vote_task)
+			kthread_stop(osb->vote_task);
+	}
+
+	mlog_exit(status);
+	return status;
+}
+
+void ocfs2_dlm_shutdown(struct ocfs2_super *osb)
+{
+	mlog_entry_void();
+
+	dlm_unregister_eviction_cb(&osb->osb_eviction_cb);
+
+	ocfs2_drop_osb_locks(osb);
+
+	if (osb->vote_task) {
+		kthread_stop(osb->vote_task);
+		osb->vote_task = NULL;
+	}
+
+	ocfs2_lock_res_free(&osb->osb_super_lockres);
+	ocfs2_lock_res_free(&osb->osb_rename_lockres);
+
+	dlm_unregister_domain(osb->dlm);
+	osb->dlm = NULL;
+
+	ocfs2_dlm_shutdown_debug(osb);
+
+	mlog_exit_void();
+}
+
+static void ocfs2_unlock_ast_func(void *opaque, enum dlm_status status)
+{
+	struct ocfs2_lock_res *lockres = opaque;
+	unsigned long flags;
+
+	mlog_entry_void();
+
+	mlog(0, "UNLOCK AST called on lock %s, action = %d\n", lockres->l_name,
+	     lockres->l_unlock_action);
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	/* We tried to cancel a convert request, but it was already
+	 * granted. All we want to do here is clear our unlock
+	 * state. The wake_up call done at the bottom is redundant
+	 * (ocfs2_prepare_cancel_convert doesn't sleep on this) but doesn't
+	 * hurt anything anyway */
+	if (status == DLM_CANCELGRANT &&
+	    lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
+		mlog(0, "Got cancelgrant for %s\n", lockres->l_name);
+
+		/* We don't clear the busy flag in this case as it
+		 * should have been cleared by the ast which the dlm
+		 * has called. */
+		goto complete_unlock;
+	}
+
+	if (status != DLM_NORMAL) {
+		mlog(ML_ERROR, "Dlm passes status %d for lock %s, "
+		     "unlock_action %d\n", status, lockres->l_name,
+		     lockres->l_unlock_action);
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		return;
+	}
+
+	switch(lockres->l_unlock_action) {
+	case OCFS2_UNLOCK_CANCEL_CONVERT:
+		mlog(0, "Cancel convert success for %s\n", lockres->l_name);
+		lockres->l_action = OCFS2_AST_INVALID;
+		break;
+	case OCFS2_UNLOCK_DROP_LOCK:
+		lockres->l_level = LKM_IVMODE;
+		break;
+	default:
+		BUG();
+	}
+
+	lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+complete_unlock:
+	lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	wake_up(&lockres->l_event);
+
+	mlog_exit_void();
+}
+
+typedef void (ocfs2_pre_drop_cb_t)(struct ocfs2_lock_res *, void *);
+
+struct drop_lock_cb {
+	ocfs2_pre_drop_cb_t	*drop_func;
+	void			*drop_data;
+};
+
+static int ocfs2_drop_lock(struct ocfs2_super *osb,
+			   struct ocfs2_lock_res *lockres,
+			   struct drop_lock_cb *dcb)
+{
+	enum dlm_status status;
+	unsigned long flags;
+
+	/* We didn't get anywhere near actually using this lockres. */
+	if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
+		goto out;
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+
+	mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
+			"lockres %s, flags 0x%lx\n",
+			lockres->l_name, lockres->l_flags);
+
+	while (lockres->l_flags & OCFS2_LOCK_BUSY) {
+		mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = "
+		     "%u, unlock_action = %u\n",
+		     lockres->l_name, lockres->l_flags, lockres->l_action,
+		     lockres->l_unlock_action);
+
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+		/* XXX: Today we just wait on any busy
+		 * locks... Perhaps we need to cancel converts in the
+		 * future? */
+		ocfs2_wait_on_busy_lock(lockres);
+
+		spin_lock_irqsave(&lockres->l_lock, flags);
+	}
+
+	if (dcb)
+		dcb->drop_func(lockres, dcb->drop_data);
+
+	if (lockres->l_flags & OCFS2_LOCK_BUSY)
+		mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
+		     lockres->l_name);
+	if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
+		mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name);
+
+	if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		goto out;
+	}
+
+	lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED);
+
+	/* make sure we never get here while waiting for an ast to
+	 * fire. */
+	BUG_ON(lockres->l_action != OCFS2_AST_INVALID);
+
+	/* is this necessary? */
+	lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+	lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK;
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	mlog(0, "lock %s\n", lockres->l_name);
+
+	status = dlmunlock(osb->dlm, &lockres->l_lksb, LKM_VALBLK,
+			   lockres->l_ops->unlock_ast, lockres);
+	if (status != DLM_NORMAL) {
+		ocfs2_log_dlm_error("dlmunlock", status, lockres);
+		mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
+		dlm_print_one_lock(lockres->l_lksb.lockid);
+		BUG();
+	}
+	mlog(0, "lock %s, successfull return from dlmunlock\n",
+	     lockres->l_name);
+
+	ocfs2_wait_on_busy_lock(lockres);
+out:
+	mlog_exit(0);
+	return 0;
+}
+
+/* Mark the lockres as being dropped. It will no longer be
+ * queued if blocking, but we still may have to wait on it
+ * being dequeued from the vote thread before we can consider
+ * it safe to drop. 
+ *
+ * You can *not* attempt to call cluster_lock on this lockres anymore. */
+void ocfs2_mark_lockres_freeing(struct ocfs2_lock_res *lockres)
+{
+	int status;
+	struct ocfs2_mask_waiter mw;
+	unsigned long flags;
+
+	ocfs2_init_mask_waiter(&mw);
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	lockres->l_flags |= OCFS2_LOCK_FREEING;
+	while (lockres->l_flags & OCFS2_LOCK_QUEUED) {
+		lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0);
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+		mlog(0, "Waiting on lockres %s\n", lockres->l_name);
+
+		status = ocfs2_wait_for_mask(&mw);
+		if (status)
+			mlog_errno(status);
+
+		spin_lock_irqsave(&lockres->l_lock, flags);
+	}
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+}
+
+static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
+{
+	int status;
+
+	mlog_entry_void();
+
+	ocfs2_mark_lockres_freeing(&osb->osb_super_lockres);
+
+	status = ocfs2_drop_lock(osb, &osb->osb_super_lockres, NULL);
+	if (status < 0)
+		mlog_errno(status);
+
+	ocfs2_mark_lockres_freeing(&osb->osb_rename_lockres);
+
+	status = ocfs2_drop_lock(osb, &osb->osb_rename_lockres, NULL);
+	if (status < 0)
+		mlog_errno(status);
+
+	mlog_exit(status);
+}
+
+static void ocfs2_meta_pre_drop(struct ocfs2_lock_res *lockres, void *data)
+{
+	struct inode *inode = data;
+
+	/* the metadata lock requires a bit more work as we have an
+	 * LVB to worry about. */
+	if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
+	    lockres->l_level == LKM_EXMODE &&
+	    !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
+		__ocfs2_stuff_meta_lvb(inode);
+}
+
+int ocfs2_drop_inode_locks(struct inode *inode)
+{
+	int status, err;
+	struct drop_lock_cb meta_dcb = { ocfs2_meta_pre_drop, inode, };
+
+	mlog_entry_void();
+
+	/* No need to call ocfs2_mark_lockres_freeing here -
+	 * ocfs2_clear_inode has done it for us. */
+
+	err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
+			      &OCFS2_I(inode)->ip_data_lockres,
+			      NULL);
+	if (err < 0)
+		mlog_errno(err);
+
+	status = err;
+
+	err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
+			      &OCFS2_I(inode)->ip_meta_lockres,
+			      &meta_dcb);
+	if (err < 0)
+		mlog_errno(err);
+	if (err < 0 && !status)
+		status = err;
+
+	err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
+			      &OCFS2_I(inode)->ip_rw_lockres,
+			      NULL);
+	if (err < 0)
+		mlog_errno(err);
+	if (err < 0 && !status)
+		status = err;
+
+	mlog_exit(status);
+	return status;
+}
+
+static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
+				      int new_level)
+{
+	assert_spin_locked(&lockres->l_lock);
+
+	BUG_ON(lockres->l_blocking <= LKM_NLMODE);
+
+	if (lockres->l_level <= new_level) {
+		mlog(ML_ERROR, "lockres->l_level (%u) <= new_level (%u)\n",
+		     lockres->l_level, new_level);
+		BUG();
+	}
+
+	mlog(0, "lock %s, new_level = %d, l_blocking = %d\n",
+	     lockres->l_name, new_level, lockres->l_blocking);
+
+	lockres->l_action = OCFS2_AST_DOWNCONVERT;
+	lockres->l_requested = new_level;
+	lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+}
+
+static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
+				  struct ocfs2_lock_res *lockres,
+				  int new_level,
+				  int lvb)
+{
+	int ret, dlm_flags = LKM_CONVERT;
+	enum dlm_status status;
+
+	mlog_entry_void();
+
+	if (lvb)
+		dlm_flags |= LKM_VALBLK;
+
+	status = dlmlock(osb->dlm,
+			 new_level,
+			 &lockres->l_lksb,
+			 dlm_flags,
+			 lockres->l_name,
+			 lockres->l_ops->ast,
+			 lockres,
+			 lockres->l_ops->bast);
+	if (status != DLM_NORMAL) {
+		ocfs2_log_dlm_error("dlmlock", status, lockres);
+		ret = -EINVAL;
+		ocfs2_recover_from_dlm_error(lockres, 1);
+		goto bail;
+	}
+
+	ret = 0;
+bail:
+	mlog_exit(ret);
+	return ret;
+}
+
+/* returns 1 when the caller should unlock and call dlmunlock */
+static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
+				        struct ocfs2_lock_res *lockres)
+{
+	assert_spin_locked(&lockres->l_lock);
+
+	mlog_entry_void();
+	mlog(0, "lock %s\n", lockres->l_name);
+
+	if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
+		/* If we're already trying to cancel a lock conversion
+		 * then just drop the spinlock and allow the caller to
+		 * requeue this lock. */
+
+		mlog(0, "Lockres %s, skip convert\n", lockres->l_name);
+		return 0;
+	}
+
+	/* were we in a convert when we got the bast fire? */
+	BUG_ON(lockres->l_action != OCFS2_AST_CONVERT &&
+	       lockres->l_action != OCFS2_AST_DOWNCONVERT);
+	/* set things up for the unlockast to know to just
+	 * clear out the ast_action and unset busy, etc. */
+	lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT;
+
+	mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY),
+			"lock %s, invalid flags: 0x%lx\n",
+			lockres->l_name, lockres->l_flags);
+
+	return 1;
+}
+
+static int ocfs2_cancel_convert(struct ocfs2_super *osb,
+				struct ocfs2_lock_res *lockres)
+{
+	int ret;
+	enum dlm_status status;
+
+	mlog_entry_void();
+	mlog(0, "lock %s\n", lockres->l_name);
+
+	ret = 0;
+	status = dlmunlock(osb->dlm,
+			   &lockres->l_lksb,
+			   LKM_CANCEL,
+			   lockres->l_ops->unlock_ast,
+			   lockres);
+	if (status != DLM_NORMAL) {
+		ocfs2_log_dlm_error("dlmunlock", status, lockres);
+		ret = -EINVAL;
+		ocfs2_recover_from_dlm_error(lockres, 0);
+	}
+
+	mlog(0, "lock %s return from dlmunlock\n", lockres->l_name);
+
+	mlog_exit(ret);
+	return ret;
+}
+
+static inline int ocfs2_can_downconvert_meta_lock(struct inode *inode,
+						  struct ocfs2_lock_res *lockres,
+						  int new_level)
+{
+	int ret;
+
+	mlog_entry_void();
+
+	BUG_ON(new_level != LKM_NLMODE && new_level != LKM_PRMODE);
+
+	if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
+		ret = 0;
+		mlog(0, "lockres %s currently being refreshed -- backing "
+		     "off!\n", lockres->l_name);
+	} else if (new_level == LKM_PRMODE)
+		ret = !lockres->l_ex_holders &&
+			ocfs2_inode_fully_checkpointed(inode);
+	else /* Must be NLMODE we're converting to. */
+		ret = !lockres->l_ro_holders && !lockres->l_ex_holders &&
+			ocfs2_inode_fully_checkpointed(inode);
+
+	mlog_exit(ret);
+	return ret;
+}
+
+static int ocfs2_do_unblock_meta(struct inode *inode,
+				 int *requeue)
+{
+	int new_level;
+	int set_lvb = 0;
+	int ret = 0;
+	struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_meta_lockres;
+	unsigned long flags;
+
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+	mlog_entry_void();
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+
+	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
+
+	mlog(0, "l_level=%d, l_blocking=%d\n", lockres->l_level,
+	     lockres->l_blocking);
+
+	BUG_ON(lockres->l_level != LKM_EXMODE &&
+	       lockres->l_level != LKM_PRMODE);
+
+	if (lockres->l_flags & OCFS2_LOCK_BUSY) {
+		*requeue = 1;
+		ret = ocfs2_prepare_cancel_convert(osb, lockres);
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		if (ret) {
+			ret = ocfs2_cancel_convert(osb, lockres);
+			if (ret < 0)
+				mlog_errno(ret);
+		}
+		goto leave;
+	}
+
+	new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
+
+	mlog(0, "l_level=%d, l_blocking=%d, new_level=%d\n",
+	     lockres->l_level, lockres->l_blocking, new_level);
+
+	if (ocfs2_can_downconvert_meta_lock(inode, lockres, new_level)) {
+		if (lockres->l_level == LKM_EXMODE)
+			set_lvb = 1;
+
+		/* If the lock hasn't been refreshed yet (rare), then
+		 * our memory inode values are old and we skip
+		 * stuffing the lvb. There's no need to actually clear
+		 * out the lvb here as it's value is still valid. */
+		if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
+			if (set_lvb)
+				__ocfs2_stuff_meta_lvb(inode);
+		} else
+			mlog(0, "lockres %s: downconverting stale lock!\n",
+			     lockres->l_name);
+
+		mlog(0, "calling ocfs2_downconvert_lock with l_level=%d, "
+		     "l_blocking=%d, new_level=%d\n",
+		     lockres->l_level, lockres->l_blocking, new_level);
+
+		ocfs2_prepare_downconvert(lockres, new_level);
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb);
+		goto leave;
+	}
+	if (!ocfs2_inode_fully_checkpointed(inode))
+		ocfs2_start_checkpoint(osb);
+
+	*requeue = 1;
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+	ret = 0;
+leave:
+	mlog_exit(ret);
+	return ret;
+}
+
+static int ocfs2_generic_unblock_lock(struct ocfs2_super *osb,
+				      struct ocfs2_lock_res *lockres,
+				      int *requeue,
+				      ocfs2_convert_worker_t *worker)
+{
+	unsigned long flags;
+	int blocking;
+	int new_level;
+	int ret = 0;
+
+	mlog_entry_void();
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+
+	BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
+
+recheck:
+	if (lockres->l_flags & OCFS2_LOCK_BUSY) {
+		*requeue = 1;
+		ret = ocfs2_prepare_cancel_convert(osb, lockres);
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		if (ret) {
+			ret = ocfs2_cancel_convert(osb, lockres);
+			if (ret < 0)
+				mlog_errno(ret);
+		}
+		goto leave;
+	}
+
+	/* if we're blocking an exclusive and we have *any* holders,
+	 * then requeue. */
+	if ((lockres->l_blocking == LKM_EXMODE)
+	    && (lockres->l_ex_holders || lockres->l_ro_holders)) {
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		*requeue = 1;
+		ret = 0;
+		goto leave;
+	}
+
+	/* If it's a PR we're blocking, then only
+	 * requeue if we've got any EX holders */
+	if (lockres->l_blocking == LKM_PRMODE &&
+	    lockres->l_ex_holders) {
+		spin_unlock_irqrestore(&lockres->l_lock, flags);
+		*requeue = 1;
+		ret = 0;
+		goto leave;
+	}
+
+	/* If we get here, then we know that there are no more
+	 * incompatible holders (and anyone asking for an incompatible
+	 * lock is blocked). We can now downconvert the lock */
+	if (!worker)
+		goto downconvert;
+
+	/* Some lockres types want to do a bit of work before
+	 * downconverting a lock. Allow that here. The worker function
+	 * may sleep, so we save off a copy of what we're blocking as
+	 * it may change while we're not holding the spin lock. */
+	blocking = lockres->l_blocking;
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	worker(lockres, blocking);
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	if (blocking != lockres->l_blocking) {
+		/* If this changed underneath us, then we can't drop
+		 * it just yet. */
+		goto recheck;
+	}
+
+downconvert:
+	*requeue = 0;
+	new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
+
+	ocfs2_prepare_downconvert(lockres, new_level);
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+	ret = ocfs2_downconvert_lock(osb, lockres, new_level, 0);
+leave:
+	mlog_exit(ret);
+	return ret;
+}
+
+static void ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
+				      int blocking)
+{
+	struct inode *inode;
+	struct address_space *mapping;
+
+	mlog_entry_void();
+
+       	inode = ocfs2_lock_res_inode(lockres);
+	mapping = inode->i_mapping;
+
+	if (filemap_fdatawrite(mapping)) {
+		mlog(ML_ERROR, "Could not sync inode %"MLFu64" for downconvert!",
+		     OCFS2_I(inode)->ip_blkno);
+	}
+	sync_mapping_buffers(mapping);
+	if (blocking == LKM_EXMODE) {
+		truncate_inode_pages(mapping, 0);
+		unmap_mapping_range(mapping, 0, 0, 0);
+	} else {
+		/* We only need to wait on the I/O if we're not also
+		 * truncating pages because truncate_inode_pages waits
+		 * for us above. We don't truncate pages if we're
+		 * blocking anything < EXMODE because we want to keep
+		 * them around in that case. */
+		filemap_fdatawait(mapping);
+	}
+
+	mlog_exit_void();
+}
+
+int ocfs2_unblock_data(struct ocfs2_lock_res *lockres,
+		       int *requeue)
+{
+	int status;
+	struct inode *inode;
+	struct ocfs2_super *osb;
+
+	mlog_entry_void();
+
+	inode = ocfs2_lock_res_inode(lockres);
+	osb = OCFS2_SB(inode->i_sb);
+
+	mlog(0, "unblock inode %"MLFu64"\n", OCFS2_I(inode)->ip_blkno);
+
+	status = ocfs2_generic_unblock_lock(osb,
+					    lockres,
+					    requeue,
+					    ocfs2_data_convert_worker);
+	if (status < 0)
+		mlog_errno(status);
+
+	mlog(0, "inode %"MLFu64", requeue = %d\n",
+	     OCFS2_I(inode)->ip_blkno, *requeue);
+
+	mlog_exit(status);
+	return status;
+}
+
+static int ocfs2_unblock_inode_lock(struct ocfs2_lock_res *lockres,
+				    int *requeue)
+{
+	int status;
+	struct inode *inode;
+
+	mlog_entry_void();
+
+	mlog(0, "Unblock lockres %s\n", lockres->l_name);
+
+	inode  = ocfs2_lock_res_inode(lockres);
+
+	status = ocfs2_generic_unblock_lock(OCFS2_SB(inode->i_sb),
+					    lockres,
+					    requeue,
+					    NULL);
+	if (status < 0)
+		mlog_errno(status);
+
+	mlog_exit(status);
+	return status;
+}
+
+
+int ocfs2_unblock_meta(struct ocfs2_lock_res *lockres,
+		       int *requeue)
+{
+	int status;
+	struct inode *inode;
+
+	mlog_entry_void();
+
+       	inode = ocfs2_lock_res_inode(lockres);
+
+	mlog(0, "unblock inode %"MLFu64"\n", OCFS2_I(inode)->ip_blkno);
+
+	status = ocfs2_do_unblock_meta(inode, requeue);
+	if (status < 0)
+		mlog_errno(status);
+
+	mlog(0, "inode %"MLFu64", requeue = %d\n",
+	     OCFS2_I(inode)->ip_blkno, *requeue);
+
+	mlog_exit(status);
+	return status;
+}
+
+/* Generic unblock function for any lockres whose private data is an
+ * ocfs2_super pointer. */
+static int ocfs2_unblock_osb_lock(struct ocfs2_lock_res *lockres,
+				  int *requeue)
+{
+	int status;
+	struct ocfs2_super *osb;
+
+	mlog_entry_void();
+
+	mlog(0, "Unblock lockres %s\n", lockres->l_name);
+
+	osb = ocfs2_lock_res_super(lockres);
+
+	status = ocfs2_generic_unblock_lock(osb,
+					    lockres,
+					    requeue,
+					    NULL);
+	if (status < 0)
+		mlog_errno(status);
+
+	mlog_exit(status);
+	return status;
+}
+
+void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
+				struct ocfs2_lock_res *lockres)
+{
+	int status;
+	int requeue = 0;
+	unsigned long flags;
+
+	/* Our reference to the lockres in this function can be
+	 * considered valid until we remove the OCFS2_LOCK_QUEUED
+	 * flag. */
+
+	mlog_entry_void();
+
+	BUG_ON(!lockres);
+	BUG_ON(!lockres->l_ops);
+	BUG_ON(!lockres->l_ops->unblock);
+
+	mlog(0, "lockres %s blocked.\n", lockres->l_name);
+
+	/* Detect whether a lock has been marked as going away while
+	 * the vote thread was processing other things. A lock can
+	 * still be marked with OCFS2_LOCK_FREEING after this check,
+	 * but short circuiting here will still save us some
+	 * performance. */
+	spin_lock_irqsave(&lockres->l_lock, flags);
+	if (lockres->l_flags & OCFS2_LOCK_FREEING)
+		goto unqueue;
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	status = lockres->l_ops->unblock(lockres, &requeue);
+	if (status < 0)
+		mlog_errno(status);
+
+	spin_lock_irqsave(&lockres->l_lock, flags);
+unqueue:
+	if (lockres->l_flags & OCFS2_LOCK_FREEING || !requeue) {
+		lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED);
+	} else
+		ocfs2_schedule_blocked_lock(osb, lockres);
+
+	mlog(0, "lockres %s, requeue = %s.\n", lockres->l_name,
+	     requeue ? "yes" : "no");
+	spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+	mlog_exit_void();
+}
+
+static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
+					struct ocfs2_lock_res *lockres)
+{
+	mlog_entry_void();
+
+	assert_spin_locked(&lockres->l_lock);
+
+	if (lockres->l_flags & OCFS2_LOCK_FREEING) {
+		/* Do not schedule a lock for downconvert when it's on
+		 * the way to destruction - any nodes wanting access
+		 * to the resource will get it soon. */
+		mlog(0, "Lockres %s won't be scheduled: flags 0x%lx\n",
+		     lockres->l_name, lockres->l_flags);
+		return;
+	}
+
+	lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
+
+	spin_lock(&osb->vote_task_lock);
+	if (list_empty(&lockres->l_blocked_list)) {
+		list_add_tail(&lockres->l_blocked_list,
+			      &osb->blocked_lock_list);
+		osb->blocked_lock_count++;
+	}
+	spin_unlock(&osb->vote_task_lock);
+
+	mlog_exit_void();
+}
+
+/* This aids in debugging situations where a bad LVB might be involved. */
+void ocfs2_dump_meta_lvb_info(u64 level,
+			      const char *function,
+			      unsigned int line,
+			      struct ocfs2_lock_res *lockres)
+{
+	struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
+
+	mlog(level, "LVB information for %s (called from %s:%u):\n",
+	     lockres->l_name, function, line);
+	mlog(level, "version: %u, clusters: %u\n",
+	     be32_to_cpu(lvb->lvb_version), be32_to_cpu(lvb->lvb_iclusters));
+	mlog(level, "size: %"MLFu64", uid %u, gid %u, mode 0x%x\n",
+	     be64_to_cpu(lvb->lvb_isize), be32_to_cpu(lvb->lvb_iuid),
+	     be32_to_cpu(lvb->lvb_igid), be16_to_cpu(lvb->lvb_imode));
+	mlog(level, "nlink %u, atime_packed 0x%"MLFx64", "
+	     "ctime_packed 0x%"MLFx64", mtime_packed 0x%"MLFx64"\n",
+	     be16_to_cpu(lvb->lvb_inlink), be64_to_cpu(lvb->lvb_iatime_packed),
+	     be64_to_cpu(lvb->lvb_ictime_packed),
+	     be64_to_cpu(lvb->lvb_imtime_packed));
+}