Merge branch 'for-next' into for-linus
[safe/jmp/linux-2.6] / fs / ocfs2 / dlmglue.c
index aea3bef..50c4ee8 100644 (file)
 #include <linux/slab.h>
 #include <linux/highmem.h>
 #include <linux/mm.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>
+#include <linux/time.h>
+#include <linux/quotaops.h>
 
 #define MLOG_MASK_PREFIX ML_DLM_GLUE
 #include <cluster/masklog.h>
@@ -57,6 +52,8 @@
 #include "slot_map.h"
 #include "super.h"
 #include "uptodate.h"
+#include "quota.h"
+#include "refcounttree.h"
 
 #include "buffer_head_io.h"
 
@@ -66,11 +63,15 @@ struct ocfs2_mask_waiter {
        struct completion       mw_complete;
        unsigned long           mw_mask;
        unsigned long           mw_goal;
+#ifdef CONFIG_OCFS2_FS_STATS
+       unsigned long long      mw_lock_start;
+#endif
 };
 
 static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
 static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
 static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres);
+static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres);
 
 /*
  * Return value from ->downconvert_worker functions.
@@ -92,6 +93,9 @@ struct ocfs2_unblock_ctl {
        enum ocfs2_unblock_action unblock_action;
 };
 
+/* Lockdep class keys */
+struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES];
+
 static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
                                        int new_level);
 static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres);
@@ -105,6 +109,12 @@ static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
 static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
                                     struct ocfs2_lock_res *lockres);
 
+static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres);
+
+static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
+                                           int new_level);
+static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
+                                        int blocking);
 
 #define mlog_meta_lvb(__level, __lockres) ocfs2_dump_meta_lvb_info(__level, __PRETTY_FUNCTION__, __LINE__, __lockres)
 
@@ -114,7 +124,7 @@ static void ocfs2_dump_meta_lvb_info(u64 level,
                                     unsigned int line,
                                     struct ocfs2_lock_res *lockres)
 {
-       struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
+       struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
 
        mlog(level, "LVB information for %s (called from %s:%u):\n",
             lockres->l_name, function, line);
@@ -243,6 +253,14 @@ static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
        .flags          = 0,
 };
 
+static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
+       .flags          = 0,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
+       .flags          = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
+};
+
 static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
        .get_osb        = ocfs2_get_dentry_osb,
        .post_unlock    = ocfs2_dentry_post_unlock,
@@ -260,29 +278,16 @@ static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
        .flags          = 0,
 };
 
-/*
- * This is the filesystem locking protocol version.
- *
- * Whenever the filesystem does new things with locks (adds or removes a
- * lock, orders them differently, does different things underneath a lock),
- * the version must be changed.  The protocol is negotiated when joining
- * the dlm domain.  A node may join the domain if its major version is
- * identical to all other nodes and its minor version is greater than
- * or equal to all other nodes.  When its minor version is greater than
- * the other nodes, it will run at the minor version specified by the
- * other nodes.
- *
- * If a locking change is made that will not be compatible with older
- * versions, the major number must be increased and the minor version set
- * to zero.  If a change merely adds a behavior that can be disabled when
- * speaking to older versions, the minor version must be increased.  If a
- * change adds a fully backwards compatible change (eg, LVB changes that
- * are just ignored by older versions), the version does not need to be
- * updated.
- */
-const struct dlm_protocol_version ocfs2_locking_protocol = {
-       .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
-       .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
+static struct ocfs2_lock_res_ops ocfs2_qinfo_lops = {
+       .set_lvb        = ocfs2_set_qinfo_lvb,
+       .get_osb        = ocfs2_get_qinfo_osb,
+       .flags          = LOCK_TYPE_REQUIRES_REFRESH | LOCK_TYPE_USES_LVB,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_refcount_block_lops = {
+       .check_downconvert = ocfs2_check_refcount_downconvert,
+       .downconvert_worker = ocfs2_refcount_convert_worker,
+       .flags          = 0,
 };
 
 static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
@@ -292,6 +297,11 @@ static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
                lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
 }
 
+static inline struct ocfs2_lock_res *ocfs2_lksb_to_lock_res(struct ocfs2_dlm_lksb *lksb)
+{
+       return container_of(lksb, struct ocfs2_lock_res, l_lksb);
+}
+
 static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
 {
        BUG_ON(!ocfs2_is_inode_lock(lockres));
@@ -306,6 +316,19 @@ static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res
        return (struct ocfs2_dentry_lock *)lockres->l_priv;
 }
 
+static inline struct ocfs2_mem_dqinfo *ocfs2_lock_res_qinfo(struct ocfs2_lock_res *lockres)
+{
+       BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_QINFO);
+
+       return (struct ocfs2_mem_dqinfo *)lockres->l_priv;
+}
+
+static inline struct ocfs2_refcount_tree *
+ocfs2_lock_res_refcount_tree(struct ocfs2_lock_res *res)
+{
+       return container_of(res, struct ocfs2_refcount_tree, rf_lockres);
+}
+
 static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres)
 {
        if (lockres->l_ops->get_osb)
@@ -317,12 +340,19 @@ static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *l
 static int ocfs2_lock_create(struct ocfs2_super *osb,
                             struct ocfs2_lock_res *lockres,
                             int level,
-                            int dlm_flags);
+                            u32 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 void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
+                                  struct ocfs2_lock_res *lockres,
+                                  int level, unsigned long caller_ip);
+static inline void ocfs2_cluster_unlock(struct ocfs2_super *osb,
+                                       struct ocfs2_lock_res *lockres,
+                                       int level)
+{
+       __ocfs2_cluster_unlock(osb, lockres, level, _RET_IP_);
+}
+
 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);
@@ -331,10 +361,14 @@ 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));           \
+#define ocfs2_log_dlm_error(_func, _err, _lockres) do {                                        \
+       if ((_lockres)->l_type != OCFS2_LOCK_TYPE_DENTRY)                               \
+               mlog(ML_ERROR, "DLM error %d while calling %s on resource %s\n",        \
+                    _err, _func, _lockres->l_name);                                    \
+       else                                                                            \
+               mlog(ML_ERROR, "DLM error %d while calling %s on resource %.*s%08x\n",  \
+                    _err, _func, OCFS2_DENTRY_LOCK_INO_START - 1, (_lockres)->l_name,  \
+                    (unsigned int)ocfs2_get_dentry_lock_ino(_lockres));                \
 } while (0)
 static int ocfs2_downconvert_thread(void *arg);
 static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
@@ -343,12 +377,13 @@ static int ocfs2_inode_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 void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
-                                     int new_level);
+static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
+                                             int new_level);
 static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
                                  struct ocfs2_lock_res *lockres,
                                  int new_level,
-                                 int lvb);
+                                 int lvb,
+                                 unsigned int generation);
 static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
                                        struct ocfs2_lock_res *lockres);
 static int ocfs2_cancel_convert(struct ocfs2_super *osb,
@@ -397,6 +432,75 @@ static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
        spin_unlock(&ocfs2_dlm_tracking_lock);
 }
 
+#ifdef CONFIG_OCFS2_FS_STATS
+static void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
+{
+       res->l_lock_num_prmode = 0;
+       res->l_lock_num_prmode_failed = 0;
+       res->l_lock_total_prmode = 0;
+       res->l_lock_max_prmode = 0;
+       res->l_lock_num_exmode = 0;
+       res->l_lock_num_exmode_failed = 0;
+       res->l_lock_total_exmode = 0;
+       res->l_lock_max_exmode = 0;
+       res->l_lock_refresh = 0;
+}
+
+static void ocfs2_update_lock_stats(struct ocfs2_lock_res *res, int level,
+                                   struct ocfs2_mask_waiter *mw, int ret)
+{
+       unsigned long long *num, *sum;
+       unsigned int *max, *failed;
+       struct timespec ts = current_kernel_time();
+       unsigned long long time = timespec_to_ns(&ts) - mw->mw_lock_start;
+
+       if (level == LKM_PRMODE) {
+               num = &res->l_lock_num_prmode;
+               sum = &res->l_lock_total_prmode;
+               max = &res->l_lock_max_prmode;
+               failed = &res->l_lock_num_prmode_failed;
+       } else if (level == LKM_EXMODE) {
+               num = &res->l_lock_num_exmode;
+               sum = &res->l_lock_total_exmode;
+               max = &res->l_lock_max_exmode;
+               failed = &res->l_lock_num_exmode_failed;
+       } else
+               return;
+
+       (*num)++;
+       (*sum) += time;
+       if (time > *max)
+               *max = time;
+       if (ret)
+               (*failed)++;
+}
+
+static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
+{
+       lockres->l_lock_refresh++;
+}
+
+static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
+{
+       struct timespec ts = current_kernel_time();
+       mw->mw_lock_start = timespec_to_ns(&ts);
+}
+#else
+static inline void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
+{
+}
+static inline void ocfs2_update_lock_stats(struct ocfs2_lock_res *res,
+                          int level, struct ocfs2_mask_waiter *mw, int ret)
+{
+}
+static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
+{
+}
+static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
+{
+}
+#endif
+
 static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
                                       struct ocfs2_lock_res *res,
                                       enum ocfs2_lock_type type,
@@ -407,15 +511,24 @@ static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
        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_level         = DLM_LOCK_IV;
+       res->l_requested     = DLM_LOCK_IV;
+       res->l_blocking      = DLM_LOCK_IV;
        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);
+
+       ocfs2_init_lock_stats(res);
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+       if (type != OCFS2_LOCK_TYPE_OPEN)
+               lockdep_init_map(&res->l_lockdep_map, ocfs2_lock_type_strings[type],
+                                &lockdep_keys[type], 0);
+       else
+               res->l_lockdep_map.key = NULL;
+#endif
 }
 
 void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
@@ -463,6 +576,13 @@ static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
        return OCFS2_SB(inode->i_sb);
 }
 
+static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres)
+{
+       struct ocfs2_mem_dqinfo *info = lockres->l_priv;
+
+       return OCFS2_SB(info->dqi_gi.dqi_sb);
+}
+
 static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres)
 {
        struct ocfs2_file_private *fp = lockres->l_priv;
@@ -550,6 +670,26 @@ static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
                                   &ocfs2_rename_lops, osb);
 }
 
+static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
+                                        struct ocfs2_super *osb)
+{
+       /* nfs_sync lockres doesn't come from a slab so we call init
+        * once on it manually.  */
+       ocfs2_lock_res_init_once(res);
+       ocfs2_build_lock_name(OCFS2_LOCK_TYPE_NFS_SYNC, 0, 0, res->l_name);
+       ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_NFS_SYNC,
+                                  &ocfs2_nfs_sync_lops, osb);
+}
+
+static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res,
+                                           struct ocfs2_super *osb)
+{
+       ocfs2_lock_res_init_once(res);
+       ocfs2_build_lock_name(OCFS2_LOCK_TYPE_ORPHAN_SCAN, 0, 0, res->l_name);
+       ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_ORPHAN_SCAN,
+                                  &ocfs2_orphan_scan_lops, osb);
+}
+
 void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
                              struct ocfs2_file_private *fp)
 {
@@ -565,6 +705,28 @@ void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
        lockres->l_flags |= OCFS2_LOCK_NOCACHE;
 }
 
+void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres,
+                              struct ocfs2_mem_dqinfo *info)
+{
+       ocfs2_lock_res_init_once(lockres);
+       ocfs2_build_lock_name(OCFS2_LOCK_TYPE_QINFO, info->dqi_gi.dqi_type,
+                             0, lockres->l_name);
+       ocfs2_lock_res_init_common(OCFS2_SB(info->dqi_gi.dqi_sb), lockres,
+                                  OCFS2_LOCK_TYPE_QINFO, &ocfs2_qinfo_lops,
+                                  info);
+}
+
+void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres,
+                                 struct ocfs2_super *osb, u64 ref_blkno,
+                                 unsigned int generation)
+{
+       ocfs2_lock_res_init_once(lockres);
+       ocfs2_build_lock_name(OCFS2_LOCK_TYPE_REFCOUNT, ref_blkno,
+                             generation, lockres->l_name);
+       ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_REFCOUNT,
+                                  &ocfs2_refcount_block_lops, osb);
+}
+
 void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
 {
        mlog_entry_void();
@@ -605,10 +767,10 @@ static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
        BUG_ON(!lockres);
 
        switch(level) {
-       case LKM_EXMODE:
+       case DLM_LOCK_EX:
                lockres->l_ex_holders++;
                break;
-       case LKM_PRMODE:
+       case DLM_LOCK_PR:
                lockres->l_ro_holders++;
                break;
        default:
@@ -626,11 +788,11 @@ static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
        BUG_ON(!lockres);
 
        switch(level) {
-       case LKM_EXMODE:
+       case DLM_LOCK_EX:
                BUG_ON(!lockres->l_ex_holders);
                lockres->l_ex_holders--;
                break;
-       case LKM_PRMODE:
+       case DLM_LOCK_PR:
                BUG_ON(!lockres->l_ro_holders);
                lockres->l_ro_holders--;
                break;
@@ -645,12 +807,12 @@ static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
  * lock types are added. */
 static inline int ocfs2_highest_compat_lock_level(int level)
 {
-       int new_level = LKM_EXMODE;
+       int new_level = DLM_LOCK_EX;
 
-       if (level == LKM_EXMODE)
-               new_level = LKM_NLMODE;
-       else if (level == LKM_PRMODE)
-               new_level = LKM_PRMODE;
+       if (level == DLM_LOCK_EX)
+               new_level = DLM_LOCK_NL;
+       else if (level == DLM_LOCK_PR)
+               new_level = DLM_LOCK_PR;
        return new_level;
 }
 
@@ -689,12 +851,12 @@ static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res
        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);
+       BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
 
        lockres->l_level = lockres->l_requested;
        if (lockres->l_level <=
            ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
-               lockres->l_blocking = LKM_NLMODE;
+               lockres->l_blocking = DLM_LOCK_NL;
                lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
        }
        lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
@@ -713,11 +875,19 @@ static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lo
         * 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 &&
+       if (lockres->l_level == DLM_LOCK_NL &&
            lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
                lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
 
        lockres->l_level = lockres->l_requested;
+
+       /*
+        * We set the OCFS2_LOCK_UPCONVERT_FINISHING flag before clearing
+        * the OCFS2_LOCK_BUSY flag to prevent the dc thread from
+        * downconverting the lock before the upconvert has fully completed.
+        */
+       lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
+
        lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
 
        mlog_exit_void();
@@ -730,7 +900,7 @@ static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *loc
        BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY)));
        BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
 
-       if (lockres->l_requested > LKM_NLMODE &&
+       if (lockres->l_requested > DLM_LOCK_NL &&
            !(lockres->l_flags & OCFS2_LOCK_LOCAL) &&
            lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
                lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
@@ -750,8 +920,6 @@ static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
 
        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
@@ -764,21 +932,134 @@ static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
                lockres->l_blocking = level;
        }
 
+       mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n",
+            lockres->l_name, level, lockres->l_level, lockres->l_blocking,
+            needs_downconvert);
+
+       if (needs_downconvert)
+               lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
+
        mlog_exit(needs_downconvert);
        return needs_downconvert;
 }
 
-static void ocfs2_blocking_ast(void *opaque, int level)
+/*
+ * OCFS2_LOCK_PENDING and l_pending_gen.
+ *
+ * Why does OCFS2_LOCK_PENDING exist?  To close a race between setting
+ * OCFS2_LOCK_BUSY and calling ocfs2_dlm_lock().  See ocfs2_unblock_lock()
+ * for more details on the race.
+ *
+ * OCFS2_LOCK_PENDING closes the race quite nicely.  However, it introduces
+ * a race on itself.  In o2dlm, we can get the ast before ocfs2_dlm_lock()
+ * returns.  The ast clears OCFS2_LOCK_BUSY, and must therefore clear
+ * OCFS2_LOCK_PENDING at the same time.  When ocfs2_dlm_lock() returns,
+ * the caller is going to try to clear PENDING again.  If nothing else is
+ * happening, __lockres_clear_pending() sees PENDING is unset and does
+ * nothing.
+ *
+ * But what if another path (eg downconvert thread) has just started a
+ * new locking action?  The other path has re-set PENDING.  Our path
+ * cannot clear PENDING, because that will re-open the original race
+ * window.
+ *
+ * [Example]
+ *
+ * ocfs2_meta_lock()
+ *  ocfs2_cluster_lock()
+ *   set BUSY
+ *   set PENDING
+ *   drop l_lock
+ *   ocfs2_dlm_lock()
+ *    ocfs2_locking_ast()              ocfs2_downconvert_thread()
+ *     clear PENDING                    ocfs2_unblock_lock()
+ *                                       take_l_lock
+ *                                       !BUSY
+ *                                       ocfs2_prepare_downconvert()
+ *                                        set BUSY
+ *                                        set PENDING
+ *                                       drop l_lock
+ *   take l_lock
+ *   clear PENDING
+ *   drop l_lock
+ *                     <window>
+ *                                       ocfs2_dlm_lock()
+ *
+ * So as you can see, we now have a window where l_lock is not held,
+ * PENDING is not set, and ocfs2_dlm_lock() has not been called.
+ *
+ * The core problem is that ocfs2_cluster_lock() has cleared the PENDING
+ * set by ocfs2_prepare_downconvert().  That wasn't nice.
+ *
+ * To solve this we introduce l_pending_gen.  A call to
+ * lockres_clear_pending() will only do so when it is passed a generation
+ * number that matches the lockres.  lockres_set_pending() will return the
+ * current generation number.  When ocfs2_cluster_lock() goes to clear
+ * PENDING, it passes the generation it got from set_pending().  In our
+ * example above, the generation numbers will *not* match.  Thus,
+ * ocfs2_cluster_lock() will not clear the PENDING set by
+ * ocfs2_prepare_downconvert().
+ */
+
+/* Unlocked version for ocfs2_locking_ast() */
+static void __lockres_clear_pending(struct ocfs2_lock_res *lockres,
+                                   unsigned int generation,
+                                   struct ocfs2_super *osb)
 {
-       struct ocfs2_lock_res *lockres = opaque;
+       assert_spin_locked(&lockres->l_lock);
+
+       /*
+        * The ast and locking functions can race us here.  The winner
+        * will clear pending, the loser will not.
+        */
+       if (!(lockres->l_flags & OCFS2_LOCK_PENDING) ||
+           (lockres->l_pending_gen != generation))
+               return;
+
+       lockres_clear_flags(lockres, OCFS2_LOCK_PENDING);
+       lockres->l_pending_gen++;
+
+       /*
+        * The downconvert thread may have skipped us because we
+        * were PENDING.  Wake it up.
+        */
+       if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
+               ocfs2_wake_downconvert_thread(osb);
+}
+
+/* Locked version for callers of ocfs2_dlm_lock() */
+static void lockres_clear_pending(struct ocfs2_lock_res *lockres,
+                                 unsigned int generation,
+                                 struct ocfs2_super *osb)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&lockres->l_lock, flags);
+       __lockres_clear_pending(lockres, generation, osb);
+       spin_unlock_irqrestore(&lockres->l_lock, flags);
+}
+
+static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres)
+{
+       assert_spin_locked(&lockres->l_lock);
+       BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
+
+       lockres_or_flags(lockres, OCFS2_LOCK_PENDING);
+
+       return lockres->l_pending_gen;
+}
+
+static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level)
+{
+       struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
        struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
        int needs_downconvert;
        unsigned long flags;
 
-       BUG_ON(level <= LKM_NLMODE);
+       BUG_ON(level <= DLM_LOCK_NL);
 
-       mlog(0, "BAST fired for lockres %s, blocking %d, level %d type %s\n",
-            lockres->l_name, level, lockres->l_level,
+       mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, "
+            "type %s\n", lockres->l_name, level, lockres->l_level,
             ocfs2_lock_type_string(lockres->l_type));
 
        /*
@@ -799,21 +1080,33 @@ static void ocfs2_blocking_ast(void *opaque, int level)
        ocfs2_wake_downconvert_thread(osb);
 }
 
-static void ocfs2_locking_ast(void *opaque)
+static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb)
 {
-       struct ocfs2_lock_res *lockres = opaque;
-       struct dlm_lockstatus *lksb = &lockres->l_lksb;
+       struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
+       struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
        unsigned long flags;
+       int status;
 
        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);
+       status = ocfs2_dlm_lock_status(&lockres->l_lksb);
+
+       if (status == -EAGAIN) {
+               lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+               goto out;
+       }
+
+       if (status) {
+               mlog(ML_ERROR, "lockres %s: lksb status value of %d!\n",
+                    lockres->l_name, status);
                spin_unlock_irqrestore(&lockres->l_lock, flags);
                return;
        }
 
+       mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, "
+            "level %d => %d\n", lockres->l_name, lockres->l_action,
+            lockres->l_unlock_action, lockres->l_level, lockres->l_requested);
+
        switch(lockres->l_action) {
        case OCFS2_AST_ATTACH:
                ocfs2_generic_handle_attach_action(lockres);
@@ -826,21 +1119,115 @@ static void ocfs2_locking_ast(void *opaque)
                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",
+               mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, "
+                    "flags 0x%lx, unlock: %u\n",
                     lockres->l_name, lockres->l_action, lockres->l_flags,
                     lockres->l_unlock_action);
                BUG();
        }
-
+out:
        /* set it to something invalid so if we get called again we
         * can catch it. */
        lockres->l_action = OCFS2_AST_INVALID;
 
+       /* Did we try to cancel this lock?  Clear that state */
+       if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT)
+               lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
+
+       /*
+        * We may have beaten the locking functions here.  We certainly
+        * know that dlm_lock() has been called :-)
+        * Because we can't have two lock calls in flight at once, we
+        * can use lockres->l_pending_gen.
+        */
+       __lockres_clear_pending(lockres, lockres->l_pending_gen,  osb);
+
        wake_up(&lockres->l_event);
        spin_unlock_irqrestore(&lockres->l_lock, flags);
 }
 
+static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error)
+{
+       struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
+       unsigned long flags;
+
+       mlog_entry_void();
+
+       mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n",
+            lockres->l_name, lockres->l_unlock_action);
+
+       spin_lock_irqsave(&lockres->l_lock, flags);
+       if (error) {
+               mlog(ML_ERROR, "Dlm passes error %d for lock %s, "
+                    "unlock_action %d\n", error, lockres->l_name,
+                    lockres->l_unlock_action);
+               spin_unlock_irqrestore(&lockres->l_lock, flags);
+               mlog_exit_void();
+               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;
+               /* Downconvert thread may have requeued this lock, we
+                * need to wake it. */
+               if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
+                       ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres));
+               break;
+       case OCFS2_UNLOCK_DROP_LOCK:
+               lockres->l_level = DLM_LOCK_IV;
+               break;
+       default:
+               BUG();
+       }
+
+       lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+       lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
+       wake_up(&lockres->l_event);
+       spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+       mlog_exit_void();
+}
+
+/*
+ * This is the filesystem locking protocol.  It provides the lock handling
+ * hooks for the underlying DLM.  It has a maximum version number.
+ * The version number allows interoperability with systems running at
+ * the same major number and an equal or smaller minor number.
+ *
+ * Whenever the filesystem does new things with locks (adds or removes a
+ * lock, orders them differently, does different things underneath a lock),
+ * the version must be changed.  The protocol is negotiated when joining
+ * the dlm domain.  A node may join the domain if its major version is
+ * identical to all other nodes and its minor version is greater than
+ * or equal to all other nodes.  When its minor version is greater than
+ * the other nodes, it will run at the minor version specified by the
+ * other nodes.
+ *
+ * If a locking change is made that will not be compatible with older
+ * versions, the major number must be increased and the minor version set
+ * to zero.  If a change merely adds a behavior that can be disabled when
+ * speaking to older versions, the minor version must be increased.  If a
+ * change adds a fully backwards compatible change (eg, LVB changes that
+ * are just ignored by older versions), the version does not need to be
+ * updated.
+ */
+static struct ocfs2_locking_protocol lproto = {
+       .lp_max_version = {
+               .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
+               .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
+       },
+       .lp_lock_ast            = ocfs2_locking_ast,
+       .lp_blocking_ast        = ocfs2_blocking_ast,
+       .lp_unlock_ast          = ocfs2_unlock_ast,
+};
+
+void ocfs2_set_locking_protocol(void)
+{
+       ocfs2_stack_glue_set_max_proto_version(&lproto.lp_max_version);
+}
+
 static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
                                                int convert)
 {
@@ -849,6 +1236,7 @@ static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
        mlog_entry_void();
        spin_lock_irqsave(&lockres->l_lock, flags);
        lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+       lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
        if (convert)
                lockres->l_action = OCFS2_AST_INVALID;
        else
@@ -866,15 +1254,15 @@ static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
 static int ocfs2_lock_create(struct ocfs2_super *osb,
                             struct ocfs2_lock_res *lockres,
                             int level,
-                            int dlm_flags)
+                            u32 dlm_flags)
 {
        int ret = 0;
-       enum dlm_status status = DLM_NORMAL;
        unsigned long flags;
+       unsigned int gen;
 
        mlog_entry_void();
 
-       mlog(0, "lock %s, level = %d, flags = %d\n", lockres->l_name, level,
+       mlog(0, "lock %s, level = %d, flags = %u\n", lockres->l_name, level,
             dlm_flags);
 
        spin_lock_irqsave(&lockres->l_lock, flags);
@@ -887,23 +1275,22 @@ static int ocfs2_lock_create(struct ocfs2_super *osb,
        lockres->l_action = OCFS2_AST_ATTACH;
        lockres->l_requested = level;
        lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+       gen = lockres_set_pending(lockres);
        spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-       status = ocfs2_dlm_lock(osb->dlm,
-                               level,
-                               &lockres->l_lksb,
-                               dlm_flags,
-                               lockres->l_name,
-                               OCFS2_LOCK_ID_MAX_LEN - 1,
-                               lockres);
-       if (status != DLM_NORMAL) {
-               ocfs2_log_dlm_error("ocfs2_dlm_lock", status, lockres);
-               ret = -EINVAL;
+       ret = ocfs2_dlm_lock(osb->cconn,
+                            level,
+                            &lockres->l_lksb,
+                            dlm_flags,
+                            lockres->l_name,
+                            OCFS2_LOCK_ID_MAX_LEN - 1);
+       lockres_clear_pending(lockres, gen, osb);
+       if (ret) {
+               ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
                ocfs2_recover_from_dlm_error(lockres, 1);
        }
 
-       mlog(0, "lock %s, successfull return from ocfs2_dlm_lock\n",
-            lockres->l_name);
+       mlog(0, "lock %s, return from ocfs2_dlm_lock\n", lockres->l_name);
 
 bail:
        mlog_exit(ret);
@@ -952,6 +1339,7 @@ static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
 {
        INIT_LIST_HEAD(&mw->mw_item);
        init_completion(&mw->mw_complete);
+       ocfs2_init_start_time(mw);
 }
 
 static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
@@ -1013,35 +1401,38 @@ static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw,
        return ret;
 }
 
-static int ocfs2_cluster_lock(struct ocfs2_super *osb,
-                             struct ocfs2_lock_res *lockres,
-                             int level,
-                             int lkm_flags,
-                             int arg_flags)
+static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
+                               struct ocfs2_lock_res *lockres,
+                               int level,
+                               u32 lkm_flags,
+                               int arg_flags,
+                               int l_subclass,
+                               unsigned long caller_ip)
 {
        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;
+       unsigned int gen;
+       int noqueue_attempted = 0;
 
        mlog_entry_void();
 
        ocfs2_init_mask_waiter(&mw);
 
        if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
-               lkm_flags |= LKM_VALBLK;
+               lkm_flags |= DLM_LKF_VALBLK;
 
 again:
        wait = 0;
 
+       spin_lock_irqsave(&lockres->l_lock, flags);
+
        if (catch_signals && signal_pending(current)) {
                ret = -ERESTARTSYS;
-               goto out;
+               goto unlock;
        }
 
-       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);
@@ -1058,6 +1449,25 @@ again:
                goto unlock;
        }
 
+       if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) {
+               /*
+                * We've upconverted. If the lock now has a level we can
+                * work with, we take it. If, however, the lock is not at the
+                * required level, we go thru the full cycle. One way this could
+                * happen is if a process requesting an upconvert to PR is
+                * closely followed by another requesting upconvert to an EX.
+                * If the process requesting EX lands here, we want it to
+                * continue attempting to upconvert and let the process
+                * requesting PR take the lock.
+                * If multiple processes request upconvert to PR, the first one
+                * here will take the lock. The others will have to go thru the
+                * OCFS2_LOCK_BLOCKED check to ensure that there is no pending
+                * downconvert request.
+                */
+               if (level <= lockres->l_level)
+                       goto update_holders;
+       }
+
        if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
            !ocfs2_may_continue_on_blocked_lock(lockres, level)) {
                /* is the lock is currently blocked on behalf of
@@ -1068,50 +1478,55 @@ again:
        }
 
        if (level > lockres->l_level) {
+               if (noqueue_attempted > 0) {
+                       ret = -EAGAIN;
+                       goto unlock;
+               }
+               if (lkm_flags & DLM_LKF_NOQUEUE)
+                       noqueue_attempted = 1;
+
                if (lockres->l_action != OCFS2_AST_INVALID)
                        mlog(ML_ERROR, "lockres %s has action %u pending\n",
                             lockres->l_name, lockres->l_action);
 
                if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
                        lockres->l_action = OCFS2_AST_ATTACH;
-                       lkm_flags &= ~LKM_CONVERT;
+                       lkm_flags &= ~DLM_LKF_CONVERT;
                } else {
                        lockres->l_action = OCFS2_AST_CONVERT;
-                       lkm_flags |= LKM_CONVERT;
+                       lkm_flags |= DLM_LKF_CONVERT;
                }
 
                lockres->l_requested = level;
                lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+               gen = lockres_set_pending(lockres);
                spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-               BUG_ON(level == LKM_IVMODE);
-               BUG_ON(level == LKM_NLMODE);
+               BUG_ON(level == DLM_LOCK_IV);
+               BUG_ON(level == DLM_LOCK_NL);
 
-               mlog(0, "lock %s, convert from %d to level = %d\n",
+               mlog(ML_BASTS, "lockres %s, convert from %d to %d\n",
                     lockres->l_name, lockres->l_level, level);
 
                /* call dlm_lock to upgrade lock now */
-               status = ocfs2_dlm_lock(osb->dlm,
-                                       level,
-                                       &lockres->l_lksb,
-                                       lkm_flags,
-                                       lockres->l_name,
-                                       OCFS2_LOCK_ID_MAX_LEN - 1,
-                                       lockres);
-               if (status != DLM_NORMAL) {
-                       if ((lkm_flags & LKM_NOQUEUE) &&
-                           (status == DLM_NOTQUEUED))
-                               ret = -EAGAIN;
-                       else {
+               ret = ocfs2_dlm_lock(osb->cconn,
+                                    level,
+                                    &lockres->l_lksb,
+                                    lkm_flags,
+                                    lockres->l_name,
+                                    OCFS2_LOCK_ID_MAX_LEN - 1);
+               lockres_clear_pending(lockres, gen, osb);
+               if (ret) {
+                       if (!(lkm_flags & DLM_LKF_NOQUEUE) ||
+                           (ret != -EAGAIN)) {
                                ocfs2_log_dlm_error("ocfs2_dlm_lock",
-                                                   status, lockres);
-                               ret = -EINVAL;
+                                                   ret, lockres);
                        }
                        ocfs2_recover_from_dlm_error(lockres, 1);
                        goto out;
                }
 
-               mlog(0, "lock %s, successfull return from ocfs2_dlm_lock\n",
+               mlog(0, "lock %s, successful return from ocfs2_dlm_lock\n",
                     lockres->l_name);
 
                /* At this point we've gone inside the dlm and need to
@@ -1122,11 +1537,14 @@ again:
                goto again;
        }
 
+update_holders:
        /* Ok, if we get here then we're good to go. */
        ocfs2_inc_holders(lockres, level);
 
        ret = 0;
 unlock:
+       lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
+
        spin_unlock_irqrestore(&lockres->l_lock, flags);
 out:
        /*
@@ -1151,14 +1569,39 @@ out:
                        goto again;
                mlog_errno(ret);
        }
-
+       ocfs2_update_lock_stats(lockres, level, &mw, ret);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+       if (!ret && lockres->l_lockdep_map.key != NULL) {
+               if (level == DLM_LOCK_PR)
+                       rwsem_acquire_read(&lockres->l_lockdep_map, l_subclass,
+                               !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
+                               caller_ip);
+               else
+                       rwsem_acquire(&lockres->l_lockdep_map, l_subclass,
+                               !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
+                               caller_ip);
+       }
+#endif
        mlog_exit(ret);
        return ret;
 }
 
-static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
-                                struct ocfs2_lock_res *lockres,
-                                int level)
+static inline int ocfs2_cluster_lock(struct ocfs2_super *osb,
+                                    struct ocfs2_lock_res *lockres,
+                                    int level,
+                                    u32 lkm_flags,
+                                    int arg_flags)
+{
+       return __ocfs2_cluster_lock(osb, lockres, level, lkm_flags, arg_flags,
+                                   0, _RET_IP_);
+}
+
+
+static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
+                                  struct ocfs2_lock_res *lockres,
+                                  int level,
+                                  unsigned long caller_ip)
 {
        unsigned long flags;
 
@@ -1167,6 +1610,10 @@ static void ocfs2_cluster_unlock(struct ocfs2_super *osb,
        ocfs2_dec_holders(lockres, level);
        ocfs2_downconvert_on_unlock(osb, lockres);
        spin_unlock_irqrestore(&lockres->l_lock, flags);
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+       if (lockres->l_lockdep_map.key != NULL)
+               rwsem_release(&lockres->l_lockdep_map, 1, caller_ip);
+#endif
        mlog_exit_void();
 }
 
@@ -1175,9 +1622,9 @@ static int ocfs2_create_new_lock(struct ocfs2_super *osb,
                                 int ex,
                                 int local)
 {
-       int level =  ex ? LKM_EXMODE : LKM_PRMODE;
+       int level =  ex ? DLM_LOCK_EX : DLM_LOCK_PR;
        unsigned long flags;
-       int lkm_flags = local ? LKM_LOCAL : 0;
+       u32 lkm_flags = local ? DLM_LKF_LOCAL : 0;
 
        spin_lock_irqsave(&lockres->l_lock, flags);
        BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
@@ -1220,7 +1667,7 @@ int ocfs2_create_new_inode_locks(struct inode *inode)
        }
 
        /*
-        * We don't want to use LKM_LOCAL on a meta data lock as they
+        * We don't want to use DLM_LKF_LOCAL on a meta data lock as they
         * don't use a generation in their lock names.
         */
        ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0);
@@ -1254,12 +1701,14 @@ int ocfs2_rw_lock(struct inode *inode, int write)
             (unsigned long long)OCFS2_I(inode)->ip_blkno,
             write ? "EXMODE" : "PRMODE");
 
-       if (ocfs2_mount_local(osb))
+       if (ocfs2_mount_local(osb)) {
+               mlog_exit(0);
                return 0;
+       }
 
        lockres = &OCFS2_I(inode)->ip_rw_lockres;
 
-       level = write ? LKM_EXMODE : LKM_PRMODE;
+       level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
 
        status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 0,
                                    0);
@@ -1272,7 +1721,7 @@ int ocfs2_rw_lock(struct inode *inode, int write)
 
 void ocfs2_rw_unlock(struct inode *inode, int write)
 {
-       int level = write ? LKM_EXMODE : LKM_PRMODE;
+       int level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
        struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 
@@ -1310,7 +1759,7 @@ int ocfs2_open_lock(struct inode *inode)
        lockres = &OCFS2_I(inode)->ip_open_lockres;
 
        status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
-                                   LKM_PRMODE, 0, 0);
+                                   DLM_LOCK_PR, 0, 0);
        if (status < 0)
                mlog_errno(status);
 
@@ -1338,16 +1787,16 @@ int ocfs2_try_open_lock(struct inode *inode, int write)
 
        lockres = &OCFS2_I(inode)->ip_open_lockres;
 
-       level = write ? LKM_EXMODE : LKM_PRMODE;
+       level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
 
        /*
         * The file system may already holding a PRMODE/EXMODE open lock.
-        * Since we pass LKM_NOQUEUE, the request won't block waiting on
+        * Since we pass DLM_LKF_NOQUEUE, the request won't block waiting on
         * other nodes and the -EAGAIN will indicate to the caller that
         * this inode is still in use.
         */
        status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
-                                   level, LKM_NOQUEUE, 0);
+                                   level, DLM_LKF_NOQUEUE, 0);
 
 out:
        mlog_exit(status);
@@ -1372,10 +1821,10 @@ void ocfs2_open_unlock(struct inode *inode)
 
        if(lockres->l_ro_holders)
                ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
-                                    LKM_PRMODE);
+                                    DLM_LOCK_PR);
        if(lockres->l_ex_holders)
                ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
-                                    LKM_EXMODE);
+                                    DLM_LOCK_EX);
 
 out:
        mlog_exit_void();
@@ -1432,7 +1881,7 @@ out:
  * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of
  * flock() calls. The locking approach this requires is sufficiently
  * different from all other cluster lock types that we implement a
- * seperate path to the "low-level" dlm calls. In particular:
+ * separate path to the "low-level" dlm calls. In particular:
  *
  * - No optimization of lock levels is done - we take at exactly
  *   what's been requested.
@@ -1451,8 +1900,8 @@ out:
  */
 int ocfs2_file_lock(struct file *file, int ex, int trylock)
 {
-       int ret, level = ex ? LKM_EXMODE : LKM_PRMODE;
-       unsigned int lkm_flags = trylock ? LKM_NOQUEUE : 0;
+       int ret, level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+       unsigned int lkm_flags = trylock ? DLM_LKF_NOQUEUE : 0;
        unsigned long flags;
        struct ocfs2_file_private *fp = file->private_data;
        struct ocfs2_lock_res *lockres = &fp->fp_flock;
@@ -1462,7 +1911,7 @@ int ocfs2_file_lock(struct file *file, int ex, int trylock)
        ocfs2_init_mask_waiter(&mw);
 
        if ((lockres->l_flags & OCFS2_LOCK_BUSY) ||
-           (lockres->l_level > LKM_NLMODE)) {
+           (lockres->l_level > DLM_LOCK_NL)) {
                mlog(ML_ERROR,
                     "File lock \"%s\" has busy or locked state: flags: 0x%lx, "
                     "level: %u\n", lockres->l_name, lockres->l_flags,
@@ -1479,7 +1928,7 @@ int ocfs2_file_lock(struct file *file, int ex, int trylock)
                 * Get the lock at NLMODE to start - that way we
                 * can cancel the upconvert request if need be.
                 */
-               ret = ocfs2_lock_create(osb, lockres, LKM_NLMODE, 0);
+               ret = ocfs2_lock_create(osb, lockres, DLM_LOCK_NL, 0);
                if (ret < 0) {
                        mlog_errno(ret);
                        goto out;
@@ -1494,20 +1943,17 @@ int ocfs2_file_lock(struct file *file, int ex, int trylock)
        }
 
        lockres->l_action = OCFS2_AST_CONVERT;
-       lkm_flags |= LKM_CONVERT;
+       lkm_flags |= DLM_LKF_CONVERT;
        lockres->l_requested = level;
        lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
 
        lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
        spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-       ret = ocfs2_dlm_lock(osb->dlm, level, &lockres->l_lksb, lkm_flags,
-                            lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1,
-                            lockres);
-       if (ret != DLM_NORMAL) {
-               if (trylock && ret == DLM_NOTQUEUED)
-                       ret = -EAGAIN;
-               else {
+       ret = ocfs2_dlm_lock(osb->cconn, level, &lockres->l_lksb, lkm_flags,
+                            lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1);
+       if (ret) {
+               if (!trylock || (ret != -EAGAIN)) {
                        ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
                        ret = -EINVAL;
                }
@@ -1532,9 +1978,13 @@ int ocfs2_file_lock(struct file *file, int ex, int trylock)
                 * outstanding lock request, so a cancel convert is
                 * required. We intentionally overwrite 'ret' - if the
                 * cancel fails and the lock was granted, it's easier
-                * to just bubble sucess back up to the user.
+                * to just bubble success back up to the user.
                 */
                ret = ocfs2_flock_handle_signal(lockres, level);
+       } else if (!ret && (level > lockres->l_level)) {
+               /* Trylock failed asynchronously */
+               BUG_ON(!trylock);
+               ret = -EAGAIN;
        }
 
 out:
@@ -1547,6 +1997,7 @@ out:
 void ocfs2_file_unlock(struct file *file)
 {
        int ret;
+       unsigned int gen;
        unsigned long flags;
        struct ocfs2_file_private *fp = file->private_data;
        struct ocfs2_lock_res *lockres = &fp->fp_flock;
@@ -1558,7 +2009,7 @@ void ocfs2_file_unlock(struct file *file)
        if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED))
                return;
 
-       if (lockres->l_level == LKM_NLMODE)
+       if (lockres->l_level == DLM_LOCK_NL)
                return;
 
        mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n",
@@ -1570,13 +2021,13 @@ void ocfs2_file_unlock(struct file *file)
         * Fake a blocking ast for the downconvert code.
         */
        lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
-       lockres->l_blocking = LKM_EXMODE;
+       lockres->l_blocking = DLM_LOCK_EX;
 
-       ocfs2_prepare_downconvert(lockres, LKM_NLMODE);
+       gen = ocfs2_prepare_downconvert(lockres, DLM_LOCK_NL);
        lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
        spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-       ret = ocfs2_downconvert_lock(osb, lockres, LKM_NLMODE, 0);
+       ret = ocfs2_downconvert_lock(osb, lockres, DLM_LOCK_NL, 0, gen);
        if (ret) {
                mlog_errno(ret);
                return;
@@ -1599,11 +2050,11 @@ static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
         * condition. */
        if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
                switch(lockres->l_blocking) {
-               case LKM_EXMODE:
+               case DLM_LOCK_EX:
                        if (!lockres->l_ex_holders && !lockres->l_ro_holders)
                                kick = 1;
                        break;
-               case LKM_PRMODE:
+               case DLM_LOCK_PR:
                        if (!lockres->l_ex_holders)
                                kick = 1;
                        break;
@@ -1646,7 +2097,7 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode)
 
        mlog_entry_void();
 
-       lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
+       lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
 
        /*
         * Invalidate the LVB of a deleted inode - this way other
@@ -1698,7 +2149,7 @@ static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
 
        mlog_meta_lvb(0, lockres);
 
-       lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
+       lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
 
        /* We're safe here without the lockres lock... */
        spin_lock(&oi->ip_lock);
@@ -1733,9 +2184,10 @@ static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
 static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode,
                                              struct ocfs2_lock_res *lockres)
 {
-       struct ocfs2_meta_lvb *lvb = (struct ocfs2_meta_lvb *) lockres->l_lksb.lvb;
+       struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
 
-       if (lvb->lvb_version == OCFS2_LVB_VERSION
+       if (ocfs2_dlm_lvb_valid(&lockres->l_lksb)
+           && lvb->lvb_version == OCFS2_LVB_VERSION
            && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation)
                return 1;
        return 0;
@@ -1829,7 +2281,7 @@ static int ocfs2_inode_lock_update(struct inode *inode,
 
        /* This will discard any caching information we might have had
         * for the inode metadata. */
-       ocfs2_metadata_cache_purge(inode);
+       ocfs2_metadata_cache_purge(INODE_CACHE(inode));
 
        ocfs2_extent_map_trunc(inode, 0);
 
@@ -1840,8 +2292,7 @@ static int ocfs2_inode_lock_update(struct inode *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);
+               status = ocfs2_read_inode_block(inode, bh);
                if (status < 0) {
                        mlog_errno(status);
                        goto bail_refresh;
@@ -1849,18 +2300,14 @@ static int ocfs2_inode_lock_update(struct inode *inode,
                fe = (struct ocfs2_dinode *) (*bh)->b_data;
 
                /* This is a good chance to make sure we're not
-                * locking an invalid object.
+                * locking an invalid object.  ocfs2_read_inode_block()
+                * already checked that the inode block is sane.
                 *
                 * 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 "
@@ -1876,6 +2323,7 @@ static int ocfs2_inode_lock_update(struct inode *inode,
                                le32_to_cpu(fe->i_flags));
 
                ocfs2_refresh_inode(inode, fe);
+               ocfs2_track_lock_refresh(lockres);
        }
 
        status = 0;
@@ -1901,11 +2349,7 @@ static int ocfs2_assign_bh(struct inode *inode,
                return 0;
        }
 
-       status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
-                                 OCFS2_I(inode)->ip_blkno,
-                                 ret_bh,
-                                 OCFS2_BH_CACHED,
-                                 inode);
+       status = ocfs2_read_inode_block(inode, ret_bh);
        if (status < 0)
                mlog_errno(status);
 
@@ -1916,12 +2360,14 @@ static int ocfs2_assign_bh(struct inode *inode,
  * returns < 0 error if the callback will never be called, otherwise
  * the result of the lock will be communicated via the callback.
  */
-int ocfs2_inode_lock_full(struct inode *inode,
-                        struct buffer_head **ret_bh,
-                        int ex,
-                        int arg_flags)
+int ocfs2_inode_lock_full_nested(struct inode *inode,
+                                struct buffer_head **ret_bh,
+                                int ex,
+                                int arg_flags,
+                                int subclass)
 {
-       int status, level, dlm_flags, acquired;
+       int status, level, acquired;
+       u32 dlm_flags;
        struct ocfs2_lock_res *lockres = NULL;
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
        struct buffer_head *local_bh = NULL;
@@ -1951,12 +2397,13 @@ int ocfs2_inode_lock_full(struct inode *inode,
                ocfs2_wait_for_recovery(osb);
 
        lockres = &OCFS2_I(inode)->ip_inode_lockres;
-       level = ex ? LKM_EXMODE : LKM_PRMODE;
+       level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
        dlm_flags = 0;
        if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
-               dlm_flags |= LKM_NOQUEUE;
+               dlm_flags |= DLM_LKF_NOQUEUE;
 
-       status = ocfs2_cluster_lock(osb, lockres, level, dlm_flags, arg_flags);
+       status = __ocfs2_cluster_lock(osb, lockres, level, dlm_flags,
+                                     arg_flags, subclass, _RET_IP_);
        if (status < 0) {
                if (status != -EAGAIN && status != -EIOCBRETRY)
                        mlog_errno(status);
@@ -2105,7 +2552,7 @@ int ocfs2_inode_lock_atime(struct inode *inode,
 void ocfs2_inode_unlock(struct inode *inode,
                       int ex)
 {
-       int level = ex ? LKM_EXMODE : LKM_PRMODE;
+       int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
        struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 
@@ -2122,11 +2569,52 @@ void ocfs2_inode_unlock(struct inode *inode,
        mlog_exit_void();
 }
 
+int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno)
+{
+       struct ocfs2_lock_res *lockres;
+       struct ocfs2_orphan_scan_lvb *lvb;
+       int status = 0;
+
+       if (ocfs2_is_hard_readonly(osb))
+               return -EROFS;
+
+       if (ocfs2_mount_local(osb))
+               return 0;
+
+       lockres = &osb->osb_orphan_scan.os_lockres;
+       status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
+       if (status < 0)
+               return status;
+
+       lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+       if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
+           lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION)
+               *seqno = be32_to_cpu(lvb->lvb_os_seqno);
+       else
+               *seqno = osb->osb_orphan_scan.os_seqno + 1;
+
+       return status;
+}
+
+void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno)
+{
+       struct ocfs2_lock_res *lockres;
+       struct ocfs2_orphan_scan_lvb *lvb;
+
+       if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) {
+               lockres = &osb->osb_orphan_scan.os_lockres;
+               lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+               lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION;
+               lvb->lvb_os_seqno = cpu_to_be32(seqno);
+               ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
+       }
+}
+
 int ocfs2_super_lock(struct ocfs2_super *osb,
                     int ex)
 {
        int status = 0;
-       int level = ex ? LKM_EXMODE : LKM_PRMODE;
+       int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
        struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
 
        mlog_entry_void();
@@ -2159,6 +2647,7 @@ int ocfs2_super_lock(struct ocfs2_super *osb,
 
                if (status < 0)
                        mlog_errno(status);
+               ocfs2_track_lock_refresh(lockres);
        }
 bail:
        mlog_exit(status);
@@ -2168,7 +2657,7 @@ bail:
 void ocfs2_super_unlock(struct ocfs2_super *osb,
                        int ex)
 {
-       int level = ex ? LKM_EXMODE : LKM_PRMODE;
+       int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
        struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
 
        if (!ocfs2_mount_local(osb))
@@ -2186,7 +2675,7 @@ int ocfs2_rename_lock(struct ocfs2_super *osb)
        if (ocfs2_mount_local(osb))
                return 0;
 
-       status = ocfs2_cluster_lock(osb, lockres, LKM_EXMODE, 0, 0);
+       status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
        if (status < 0)
                mlog_errno(status);
 
@@ -2198,13 +2687,41 @@ void ocfs2_rename_unlock(struct ocfs2_super *osb)
        struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
 
        if (!ocfs2_mount_local(osb))
-               ocfs2_cluster_unlock(osb, lockres, LKM_EXMODE);
+               ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
+}
+
+int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex)
+{
+       int status;
+       struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
+
+       if (ocfs2_is_hard_readonly(osb))
+               return -EROFS;
+
+       if (ocfs2_mount_local(osb))
+               return 0;
+
+       status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE,
+                                   0, 0);
+       if (status < 0)
+               mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status);
+
+       return status;
+}
+
+void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
+{
+       struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
+
+       if (!ocfs2_mount_local(osb))
+               ocfs2_cluster_unlock(osb, lockres,
+                                    ex ? LKM_EXMODE : LKM_PRMODE);
 }
 
 int ocfs2_dentry_lock(struct dentry *dentry, int ex)
 {
        int ret;
-       int level = ex ? LKM_EXMODE : LKM_PRMODE;
+       int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
        struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
        struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 
@@ -2225,7 +2742,7 @@ int ocfs2_dentry_lock(struct dentry *dentry, int ex)
 
 void ocfs2_dentry_unlock(struct dentry *dentry, int ex)
 {
-       int level = ex ? LKM_EXMODE : LKM_PRMODE;
+       int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
        struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
        struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 
@@ -2353,7 +2870,7 @@ static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
 }
 
 /* So that debugfs.ocfs2 can determine which format is being used */
-#define OCFS2_DLM_DEBUG_STR_VERSION 1
+#define OCFS2_DLM_DEBUG_STR_VERSION 2
 static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
 {
        int i;
@@ -2390,10 +2907,51 @@ static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
                   lockres->l_blocking);
 
        /* Dump the raw LVB */
-       lvb = lockres->l_lksb.lvb;
+       lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
        for(i = 0; i < DLM_LVB_LEN; i++)
                seq_printf(m, "0x%x\t", lvb[i]);
 
+#ifdef CONFIG_OCFS2_FS_STATS
+# define lock_num_prmode(_l)           (_l)->l_lock_num_prmode
+# define lock_num_exmode(_l)           (_l)->l_lock_num_exmode
+# define lock_num_prmode_failed(_l)    (_l)->l_lock_num_prmode_failed
+# define lock_num_exmode_failed(_l)    (_l)->l_lock_num_exmode_failed
+# define lock_total_prmode(_l)         (_l)->l_lock_total_prmode
+# define lock_total_exmode(_l)         (_l)->l_lock_total_exmode
+# define lock_max_prmode(_l)           (_l)->l_lock_max_prmode
+# define lock_max_exmode(_l)           (_l)->l_lock_max_exmode
+# define lock_refresh(_l)              (_l)->l_lock_refresh
+#else
+# define lock_num_prmode(_l)           (0ULL)
+# define lock_num_exmode(_l)           (0ULL)
+# define lock_num_prmode_failed(_l)    (0)
+# define lock_num_exmode_failed(_l)    (0)
+# define lock_total_prmode(_l)         (0ULL)
+# define lock_total_exmode(_l)         (0ULL)
+# define lock_max_prmode(_l)           (0)
+# define lock_max_exmode(_l)           (0)
+# define lock_refresh(_l)              (0)
+#endif
+       /* The following seq_print was added in version 2 of this output */
+       seq_printf(m, "%llu\t"
+                  "%llu\t"
+                  "%u\t"
+                  "%u\t"
+                  "%llu\t"
+                  "%llu\t"
+                  "%u\t"
+                  "%u\t"
+                  "%u\t",
+                  lock_num_prmode(lockres),
+                  lock_num_exmode(lockres),
+                  lock_num_prmode_failed(lockres),
+                  lock_num_exmode_failed(lockres),
+                  lock_total_prmode(lockres),
+                  lock_total_exmode(lockres),
+                  lock_max_prmode(lockres),
+                  lock_max_exmode(lockres),
+                  lock_refresh(lockres));
+
        /* End the line */
        seq_printf(m, "\n");
        return 0;
@@ -2494,13 +3052,14 @@ static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
 int ocfs2_dlm_init(struct ocfs2_super *osb)
 {
        int status = 0;
-       u32 dlm_key;
-       struct dlm_ctxt *dlm = NULL;
+       struct ocfs2_cluster_connection *conn = NULL;
 
        mlog_entry_void();
 
-       if (ocfs2_mount_local(osb))
+       if (ocfs2_mount_local(osb)) {
+               osb->node_num = 0;
                goto local;
+       }
 
        status = ocfs2_dlm_init_debug(osb);
        if (status < 0) {
@@ -2517,26 +3076,33 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
                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,
-                                 &osb->osb_locking_proto);
-       if (IS_ERR(dlm)) {
-               status = PTR_ERR(dlm);
+       status = ocfs2_cluster_connect(osb->osb_cluster_stack,
+                                      osb->uuid_str,
+                                      strlen(osb->uuid_str),
+                                      &lproto, ocfs2_do_node_down, osb,
+                                      &conn);
+       if (status) {
                mlog_errno(status);
                goto bail;
        }
 
-       dlm_register_eviction_cb(dlm, &osb->osb_eviction_cb);
+       status = ocfs2_cluster_this_node(&osb->node_num);
+       if (status < 0) {
+               mlog_errno(status);
+               mlog(ML_ERROR,
+                    "could not find this host's node number\n");
+               ocfs2_cluster_disconnect(conn, 0);
+               goto bail;
+       }
 
 local:
        ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
        ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
+       ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
+       ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb);
 
-       osb->dlm = dlm;
+       osb->cconn = conn;
 
        status = 0;
 bail:
@@ -2550,14 +3116,19 @@ bail:
        return status;
 }
 
-void ocfs2_dlm_shutdown(struct ocfs2_super *osb)
+void ocfs2_dlm_shutdown(struct ocfs2_super *osb,
+                       int hangup_pending)
 {
        mlog_entry_void();
 
-       dlm_unregister_eviction_cb(&osb->osb_eviction_cb);
-
        ocfs2_drop_osb_locks(osb);
 
+       /*
+        * Now that we have dropped all locks and ocfs2_dismount_volume()
+        * has disabled recovery, the DLM won't be talking to us.  It's
+        * safe to tear things down before disconnecting the cluster.
+        */
+
        if (osb->dc_task) {
                kthread_stop(osb->dc_task);
                osb->dc_task = NULL;
@@ -2565,84 +3136,30 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb)
 
        ocfs2_lock_res_free(&osb->osb_super_lockres);
        ocfs2_lock_res_free(&osb->osb_rename_lockres);
+       ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres);
+       ocfs2_lock_res_free(&osb->osb_orphan_scan.os_lockres);
 
-       dlm_unregister_domain(osb->dlm);
-       osb->dlm = NULL;
+       ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
+       osb->cconn = NULL;
 
        ocfs2_dlm_shutdown_debug(osb);
 
        mlog_exit_void();
 }
 
-static void ocfs2_unlock_ast(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();
-}
-
 static int ocfs2_drop_lock(struct ocfs2_super *osb,
                           struct ocfs2_lock_res *lockres)
 {
-       enum dlm_status status;
+       int ret;
        unsigned long flags;
-       int lkm_flags = 0;
+       u32 lkm_flags = 0;
 
        /* We didn't get anywhere near actually using this lockres. */
        if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
                goto out;
 
        if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
-               lkm_flags |= LKM_VALBLK;
+               lkm_flags |= DLM_LKF_VALBLK;
 
        spin_lock_irqsave(&lockres->l_lock, flags);
 
@@ -2668,7 +3185,7 @@ static int ocfs2_drop_lock(struct ocfs2_super *osb,
 
        if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
                if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
-                   lockres->l_level == LKM_EXMODE &&
+                   lockres->l_level == DLM_LOCK_EX &&
                    !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
                        lockres->l_ops->set_lvb(lockres);
        }
@@ -2697,15 +3214,14 @@ static int ocfs2_drop_lock(struct ocfs2_super *osb,
 
        mlog(0, "lock %s\n", lockres->l_name);
 
-       status = ocfs2_dlm_unlock(osb->dlm, &lockres->l_lksb, lkm_flags,
-                                 lockres);
-       if (status != DLM_NORMAL) {
-               ocfs2_log_dlm_error("ocfs2_dlm_unlock", status, lockres);
+       ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, lkm_flags);
+       if (ret) {
+               ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
                mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
-               dlm_print_one_lock(lockres->l_lksb.lockid);
+               ocfs2_dlm_dump_lksb(&lockres->l_lksb);
                BUG();
        }
-       mlog(0, "lock %s, successfull return from ocfs2_dlm_unlock\n",
+       mlog(0, "lock %s, successful return from ocfs2_dlm_unlock\n",
             lockres->l_name);
 
        ocfs2_wait_on_busy_lock(lockres);
@@ -2717,7 +3233,7 @@ out:
 /* 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 downconvert thread before we can consider
- * it safe to drop. 
+ * 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)
@@ -2760,6 +3276,8 @@ static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
 {
        ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
        ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
+       ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres);
+       ocfs2_simple_drop_lockres(osb, &osb->osb_orphan_scan.os_lockres);
 }
 
 int ocfs2_drop_inode_locks(struct inode *inode)
@@ -2796,50 +3314,61 @@ int ocfs2_drop_inode_locks(struct inode *inode)
        return status;
 }
 
-static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
-                                     int new_level)
+static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
+                                             int new_level)
 {
        assert_spin_locked(&lockres->l_lock);
 
-       BUG_ON(lockres->l_blocking <= LKM_NLMODE);
+       BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
 
        if (lockres->l_level <= new_level) {
-               mlog(ML_ERROR, "lockres->l_level (%u) <= new_level (%u)\n",
-                    lockres->l_level, new_level);
+               mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, "
+                    "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, "
+                    "block %d, pgen %d\n", lockres->l_name, lockres->l_level,
+                    new_level, list_empty(&lockres->l_blocked_list),
+                    list_empty(&lockres->l_mask_waiters), lockres->l_type,
+                    lockres->l_flags, lockres->l_ro_holders,
+                    lockres->l_ex_holders, lockres->l_action,
+                    lockres->l_unlock_action, lockres->l_requested,
+                    lockres->l_blocking, lockres->l_pending_gen);
                BUG();
        }
 
-       mlog(0, "lock %s, new_level = %d, l_blocking = %d\n",
-            lockres->l_name, new_level, lockres->l_blocking);
+       mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n",
+            lockres->l_name, lockres->l_level, new_level, lockres->l_blocking);
 
        lockres->l_action = OCFS2_AST_DOWNCONVERT;
        lockres->l_requested = new_level;
        lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+       return lockres_set_pending(lockres);
 }
 
 static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
                                  struct ocfs2_lock_res *lockres,
                                  int new_level,
-                                 int lvb)
+                                 int lvb,
+                                 unsigned int generation)
 {
-       int ret, dlm_flags = LKM_CONVERT;
-       enum dlm_status status;
+       int ret;
+       u32 dlm_flags = DLM_LKF_CONVERT;
 
        mlog_entry_void();
 
+       mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name,
+            lockres->l_level, new_level);
+
        if (lvb)
-               dlm_flags |= LKM_VALBLK;
-
-       status = ocfs2_dlm_lock(osb->dlm,
-                               new_level,
-                               &lockres->l_lksb,
-                               dlm_flags,
-                               lockres->l_name,
-                               OCFS2_LOCK_ID_MAX_LEN - 1,
-                               lockres);
-       if (status != DLM_NORMAL) {
-               ocfs2_log_dlm_error("ocfs2_dlm_lock", status, lockres);
-               ret = -EINVAL;
+               dlm_flags |= DLM_LKF_VALBLK;
+
+       ret = ocfs2_dlm_lock(osb->cconn,
+                            new_level,
+                            &lockres->l_lksb,
+                            dlm_flags,
+                            lockres->l_name,
+                            OCFS2_LOCK_ID_MAX_LEN - 1);
+       lockres_clear_pending(lockres, generation, osb);
+       if (ret) {
+               ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
                ocfs2_recover_from_dlm_error(lockres, 1);
                goto bail;
        }
@@ -2857,14 +3386,12 @@ static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
        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);
+               mlog(ML_BASTS, "lockres %s, skip convert\n", lockres->l_name);
                return 0;
        }
 
@@ -2879,6 +3406,8 @@ static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
                        "lock %s, invalid flags: 0x%lx\n",
                        lockres->l_name, lockres->l_flags);
 
+       mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
+
        return 1;
 }
 
@@ -2886,23 +3415,17 @@ 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 = ocfs2_dlm_unlock(osb->dlm,
-                                 &lockres->l_lksb,
-                                 LKM_CANCEL,
-                                 lockres);
-       if (status != DLM_NORMAL) {
-               ocfs2_log_dlm_error("ocfs2_dlm_unlock", status, lockres);
-               ret = -EINVAL;
+       ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb,
+                              DLM_LKF_CANCEL);
+       if (ret) {
+               ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
                ocfs2_recover_from_dlm_error(lockres, 0);
        }
 
-       mlog(0, "lock %s return from ocfs2_dlm_unlock\n", lockres->l_name);
+       mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
 
        mlog_exit(ret);
        return ret;
@@ -2915,17 +3438,56 @@ static int ocfs2_unblock_lock(struct ocfs2_super *osb,
        unsigned long flags;
        int blocking;
        int new_level;
+       int level;
        int ret = 0;
        int set_lvb = 0;
+       unsigned int gen;
 
        mlog_entry_void();
 
        spin_lock_irqsave(&lockres->l_lock, flags);
 
-       BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
-
 recheck:
+       /*
+        * Is it still blocking? If not, we have no more work to do.
+        */
+       if (!(lockres->l_flags & OCFS2_LOCK_BLOCKED)) {
+               BUG_ON(lockres->l_blocking != DLM_LOCK_NL);
+               spin_unlock_irqrestore(&lockres->l_lock, flags);
+               ret = 0;
+               goto leave;
+       }
+
        if (lockres->l_flags & OCFS2_LOCK_BUSY) {
+               /* XXX
+                * This is a *big* race.  The OCFS2_LOCK_PENDING flag
+                * exists entirely for one reason - another thread has set
+                * OCFS2_LOCK_BUSY, but has *NOT* yet called dlm_lock().
+                *
+                * If we do ocfs2_cancel_convert() before the other thread
+                * calls dlm_lock(), our cancel will do nothing.  We will
+                * get no ast, and we will have no way of knowing the
+                * cancel failed.  Meanwhile, the other thread will call
+                * into dlm_lock() and wait...forever.
+                *
+                * Why forever?  Because another node has asked for the
+                * lock first; that's why we're here in unblock_lock().
+                *
+                * The solution is OCFS2_LOCK_PENDING.  When PENDING is
+                * set, we just requeue the unblock.  Only when the other
+                * thread has called dlm_lock() and cleared PENDING will
+                * we then cancel their request.
+                *
+                * All callers of dlm_lock() must set OCFS2_DLM_PENDING
+                * at the same time they set OCFS2_DLM_BUSY.  They must
+                * clear OCFS2_DLM_PENDING after dlm_lock() returns.
+                */
+               if (lockres->l_flags & OCFS2_LOCK_PENDING) {
+                       mlog(ML_BASTS, "lockres %s, ReQ: Pending\n",
+                            lockres->l_name);
+                       goto leave_requeue;
+               }
+
                ctl->requeue = 1;
                ret = ocfs2_prepare_cancel_convert(osb, lockres);
                spin_unlock_irqrestore(&lockres->l_lock, flags);
@@ -2937,31 +3499,70 @@ recheck:
                goto leave;
        }
 
+       /*
+        * This prevents livelocks. OCFS2_LOCK_UPCONVERT_FINISHING flag is
+        * set when the ast is received for an upconvert just before the
+        * OCFS2_LOCK_BUSY flag is cleared. Now if the fs received a bast
+        * on the heels of the ast, we want to delay the downconvert just
+        * enough to allow the up requestor to do its task. Because this
+        * lock is in the blocked queue, the lock will be downconverted
+        * as soon as the requestor is done with the lock.
+        */
+       if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING)
+               goto leave_requeue;
+
+       /*
+        * How can we block and yet be at NL?  We were trying to upconvert
+        * from NL and got canceled.  The code comes back here, and now
+        * we notice and clear BLOCKING.
+        */
+       if (lockres->l_level == DLM_LOCK_NL) {
+               BUG_ON(lockres->l_ex_holders || lockres->l_ro_holders);
+               mlog(ML_BASTS, "lockres %s, Aborting dc\n", lockres->l_name);
+               lockres->l_blocking = DLM_LOCK_NL;
+               lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
+               spin_unlock_irqrestore(&lockres->l_lock, flags);
+               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))
+       if ((lockres->l_blocking == DLM_LOCK_EX)
+           && (lockres->l_ex_holders || lockres->l_ro_holders)) {
+               mlog(ML_BASTS, "lockres %s, ReQ: EX/PR Holders %u,%u\n",
+                    lockres->l_name, lockres->l_ex_holders,
+                    lockres->l_ro_holders);
                goto leave_requeue;
+       }
 
        /* 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)
+       if (lockres->l_blocking == DLM_LOCK_PR &&
+           lockres->l_ex_holders) {
+               mlog(ML_BASTS, "lockres %s, ReQ: EX Holders %u\n",
+                    lockres->l_name, lockres->l_ex_holders);
                goto leave_requeue;
+       }
 
        /*
         * Can we get a lock in this state if the holder counts are
         * zero? The meta data unblock code used to check this.
         */
        if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
-           && (lockres->l_flags & OCFS2_LOCK_REFRESHING))
+           && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) {
+               mlog(ML_BASTS, "lockres %s, ReQ: Lock Refreshing\n",
+                    lockres->l_name);
                goto leave_requeue;
+       }
 
        new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
 
        if (lockres->l_ops->check_downconvert
-           && !lockres->l_ops->check_downconvert(lockres, new_level))
+           && !lockres->l_ops->check_downconvert(lockres, new_level)) {
+               mlog(ML_BASTS, "lockres %s, ReQ: Checkpointing\n",
+                    lockres->l_name);
                goto leave_requeue;
+       }
 
        /* If we get here, then we know that there are no more
         * incompatible holders (and anyone asking for an incompatible
@@ -2974,17 +3575,24 @@ recheck:
         * 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;
+       level = lockres->l_level;
        spin_unlock_irqrestore(&lockres->l_lock, flags);
 
        ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking);
 
-       if (ctl->unblock_action == UNBLOCK_STOP_POST)
+       if (ctl->unblock_action == UNBLOCK_STOP_POST) {
+               mlog(ML_BASTS, "lockres %s, UNBLOCK_STOP_POST\n",
+                    lockres->l_name);
                goto leave;
+       }
 
        spin_lock_irqsave(&lockres->l_lock, flags);
-       if (blocking != lockres->l_blocking) {
+       if ((blocking != lockres->l_blocking) || (level != lockres->l_level)) {
                /* If this changed underneath us, then we can't drop
                 * it just yet. */
+               mlog(ML_BASTS, "lockres %s, block=%d:%d, level=%d:%d, "
+                    "Recheck\n", lockres->l_name, blocking,
+                    lockres->l_blocking, level, lockres->l_level);
                goto recheck;
        }
 
@@ -2992,7 +3600,7 @@ downconvert:
        ctl->requeue = 0;
 
        if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
-               if (lockres->l_level == LKM_EXMODE)
+               if (lockres->l_level == DLM_LOCK_EX)
                        set_lvb = 1;
 
                /*
@@ -3005,9 +3613,11 @@ downconvert:
                        lockres->l_ops->set_lvb(lockres);
        }
 
-       ocfs2_prepare_downconvert(lockres, new_level);
+       gen = ocfs2_prepare_downconvert(lockres, new_level);
        spin_unlock_irqrestore(&lockres->l_lock, flags);
-       ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb);
+       ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb,
+                                    gen);
+
 leave:
        mlog_exit(ret);
        return ret;
@@ -3046,7 +3656,7 @@ static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
                     (unsigned long long)OCFS2_I(inode)->ip_blkno);
        }
        sync_mapping_buffers(mapping);
-       if (blocking == LKM_EXMODE) {
+       if (blocking == DLM_LOCK_EX) {
                truncate_inode_pages(mapping, 0);
        } else {
                /* We only need to wait on the I/O if we're not also
@@ -3061,22 +3671,30 @@ out:
        return UNBLOCK_CONTINUE;
 }
 
-static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
-                                       int new_level)
+static int ocfs2_ci_checkpointed(struct ocfs2_caching_info *ci,
+                                struct ocfs2_lock_res *lockres,
+                                int new_level)
 {
-       struct inode *inode = ocfs2_lock_res_inode(lockres);
-       int checkpointed = ocfs2_inode_fully_checkpointed(inode);
+       int checkpointed = ocfs2_ci_fully_checkpointed(ci);
 
-       BUG_ON(new_level != LKM_NLMODE && new_level != LKM_PRMODE);
-       BUG_ON(lockres->l_level != LKM_EXMODE && !checkpointed);
+       BUG_ON(new_level != DLM_LOCK_NL && new_level != DLM_LOCK_PR);
+       BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed);
 
        if (checkpointed)
                return 1;
 
-       ocfs2_start_checkpoint(OCFS2_SB(inode->i_sb));
+       ocfs2_start_checkpoint(OCFS2_SB(ocfs2_metadata_cache_get_super(ci)));
        return 0;
 }
 
+static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
+                                       int new_level)
+{
+       struct inode *inode = ocfs2_lock_res_inode(lockres);
+
+       return ocfs2_ci_checkpointed(INODE_CACHE(inode), lockres, new_level);
+}
+
 static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
 {
        struct inode *inode = ocfs2_lock_res_inode(lockres);
@@ -3132,7 +3750,7 @@ static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
         * valid. The downconvert code will retain a PR for this node,
         * so there's no further work to do.
         */
-       if (blocking == LKM_PRMODE)
+       if (blocking == DLM_LOCK_PR)
                return UNBLOCK_CONTINUE;
 
        /*
@@ -3206,21 +3824,167 @@ static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
        return UNBLOCK_CONTINUE_POST;
 }
 
-static struct ocfs2_locking_protocol lproto = {
-       .lp_lock_ast            = ocfs2_locking_ast,
-       .lp_blocking_ast        = ocfs2_blocking_ast,
-       .lp_unlock_ast          = ocfs2_unlock_ast,
-};
+static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
+                                           int new_level)
+{
+       struct ocfs2_refcount_tree *tree =
+                               ocfs2_lock_res_refcount_tree(lockres);
+
+       return ocfs2_ci_checkpointed(&tree->rf_ci, lockres, new_level);
+}
+
+static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
+                                        int blocking)
+{
+       struct ocfs2_refcount_tree *tree =
+                               ocfs2_lock_res_refcount_tree(lockres);
 
-/* This interface isn't the final one, hence the less-than-perfect names */
-void dlmglue_init_stack(void)
+       ocfs2_metadata_cache_purge(&tree->rf_ci);
+
+       return UNBLOCK_CONTINUE;
+}
+
+static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres)
 {
-       o2cb_get_stack(&lproto);
+       struct ocfs2_qinfo_lvb *lvb;
+       struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres);
+       struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
+                                           oinfo->dqi_gi.dqi_type);
+
+       mlog_entry_void();
+
+       lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+       lvb->lvb_version = OCFS2_QINFO_LVB_VERSION;
+       lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace);
+       lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace);
+       lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms);
+       lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks);
+       lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk);
+       lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry);
+
+       mlog_exit_void();
 }
 
-void dlmglue_exit_stack(void)
+void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex)
 {
-       o2cb_put_stack();
+       struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
+       struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
+       int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+
+       mlog_entry_void();
+       if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
+               ocfs2_cluster_unlock(osb, lockres, level);
+       mlog_exit_void();
+}
+
+static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo)
+{
+       struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
+                                           oinfo->dqi_gi.dqi_type);
+       struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
+       struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+       struct buffer_head *bh = NULL;
+       struct ocfs2_global_disk_dqinfo *gdinfo;
+       int status = 0;
+
+       if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
+           lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) {
+               info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace);
+               info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace);
+               oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms);
+               oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks);
+               oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk);
+               oinfo->dqi_gi.dqi_free_entry =
+                                       be32_to_cpu(lvb->lvb_free_entry);
+       } else {
+               status = ocfs2_read_quota_block(oinfo->dqi_gqinode, 0, &bh);
+               if (status) {
+                       mlog_errno(status);
+                       goto bail;
+               }
+               gdinfo = (struct ocfs2_global_disk_dqinfo *)
+                                       (bh->b_data + OCFS2_GLOBAL_INFO_OFF);
+               info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace);
+               info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace);
+               oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms);
+               oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks);
+               oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk);
+               oinfo->dqi_gi.dqi_free_entry =
+                                       le32_to_cpu(gdinfo->dqi_free_entry);
+               brelse(bh);
+               ocfs2_track_lock_refresh(lockres);
+       }
+
+bail:
+       return status;
+}
+
+/* Lock quota info, this function expects at least shared lock on the quota file
+ * so that we can safely refresh quota info from disk. */
+int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex)
+{
+       struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
+       struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
+       int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+       int status = 0;
+
+       mlog_entry_void();
+
+       /* On RO devices, locking really isn't needed... */
+       if (ocfs2_is_hard_readonly(osb)) {
+               if (ex)
+                       status = -EROFS;
+               goto bail;
+       }
+       if (ocfs2_mount_local(osb))
+               goto bail;
+
+       status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
+       if (status < 0) {
+               mlog_errno(status);
+               goto bail;
+       }
+       if (!ocfs2_should_refresh_lock_res(lockres))
+               goto bail;
+       /* OK, we have the lock but we need to refresh the quota info */
+       status = ocfs2_refresh_qinfo(oinfo);
+       if (status)
+               ocfs2_qinfo_unlock(oinfo, ex);
+       ocfs2_complete_lock_res_refresh(lockres, status);
+bail:
+       mlog_exit(status);
+       return status;
+}
+
+int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex)
+{
+       int status;
+       int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+       struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
+       struct ocfs2_super *osb = lockres->l_priv;
+
+
+       if (ocfs2_is_hard_readonly(osb))
+               return -EROFS;
+
+       if (ocfs2_mount_local(osb))
+               return 0;
+
+       status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
+       if (status < 0)
+               mlog_errno(status);
+
+       return status;
+}
+
+void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex)
+{
+       int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+       struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
+       struct ocfs2_super *osb = lockres->l_priv;
+
+       if (!ocfs2_mount_local(osb))
+               ocfs2_cluster_unlock(osb, lockres, level);
 }
 
 static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
@@ -3239,7 +4003,7 @@ static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
        BUG_ON(!lockres);
        BUG_ON(!lockres->l_ops);
 
-       mlog(0, "lockres %s blocked.\n", lockres->l_name);
+       mlog(ML_BASTS, "lockres %s blocked\n", lockres->l_name);
 
        /* Detect whether a lock has been marked as going away while
         * the downconvert thread was processing other things. A lock can
@@ -3262,7 +4026,7 @@ unqueue:
        } else
                ocfs2_schedule_blocked_lock(osb, lockres);
 
-       mlog(0, "lockres %s, requeue = %s.\n", lockres->l_name,
+       mlog(ML_BASTS, "lockres %s, requeue = %s.\n", lockres->l_name,
             ctl.requeue ? "yes" : "no");
        spin_unlock_irqrestore(&lockres->l_lock, flags);
 
@@ -3284,7 +4048,7 @@ static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
                /* 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",
+               mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n",
                     lockres->l_name, lockres->l_flags);
                return;
        }