This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / fs / ocfs2 / dlmglue.c
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
new file mode 100644 (file)
index 0000000..64cd528
--- /dev/null
@@ -0,0 +1,2907 @@
+/* -*- 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%016llx%08x",
+                      ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD,
+                      (long long)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 %llu, l_action = %u, type = %s\n",
+            (unsigned long long)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 %llu\n", lksb->status,
+                    (unsigned long long)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 %llu, blocking %d, level %d type %s\n",
+            (unsigned long long)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 %llu\n", (unsigned long long)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 %llu take %s RW lock\n",
+            (unsigned long long)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 %llu drop %s RW lock\n",
+            (unsigned long long)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 %llu take %s DATA lock\n",
+            (unsigned long long)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 %llu drop %s DATA lock\n",
+            (unsigned long long)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 %llu was deleted while we "
+                    "were waiting on a lock. ip_flags = 0x%x\n",
+                    (unsigned long long)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 %llu\n",
+                    (unsigned long long)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 %llu disk generation: %u "
+                               "inode->i_generation: %u\n",
+                               (unsigned long long)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 %llu dtime: %llu flags: 0x%x\n",
+                               (unsigned long long)oi->ip_blkno,
+                               (unsigned long long)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 %llu, take %s META lock\n",
+            (unsigned long long)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 %llu drop %s META lock\n",
+            (unsigned long long)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 const 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 %llu for downconvert!",
+                    (unsigned long long)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 %llu\n",
+            (unsigned long long)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 %llu, requeue = %d\n",
+            (unsigned long long)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 %llu\n",
+            (unsigned long long)OCFS2_I(inode)->ip_blkno);
+
+       status = ocfs2_do_unblock_meta(inode, requeue);
+       if (status < 0)
+               mlog_errno(status);
+
+       mlog(0, "inode %llu, requeue = %d\n",
+            (unsigned long long)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: %llu, uid %u, gid %u, mode 0x%x\n",
+            (unsigned long long)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%llx, ctime_packed 0x%llx, "
+            "mtime_packed 0x%llx\n", be16_to_cpu(lvb->lvb_inlink),
+            (long long)be64_to_cpu(lvb->lvb_iatime_packed),
+            (long long)be64_to_cpu(lvb->lvb_ictime_packed),
+            (long long)be64_to_cpu(lvb->lvb_imtime_packed));
+}