ocfs2: Fix setting of OCFS2_LOCK_BLOCKED during bast
[safe/jmp/linux-2.6] / fs / ocfs2 / dlmglue.c
index c7653bb..0cdf630 100644 (file)
@@ -31,6 +31,8 @@
 #include <linux/pagemap.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
+#include <linux/time.h>
+#include <linux/quotaops.h>
 
 #define MLOG_MASK_PREFIX ML_DLM_GLUE
 #include <cluster/masklog.h>
@@ -50,6 +52,8 @@
 #include "slot_map.h"
 #include "super.h"
 #include "uptodate.h"
+#include "quota.h"
+#include "refcounttree.h"
 
 #include "buffer_head_io.h"
 
@@ -59,11 +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.
@@ -85,6 +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);
@@ -98,6 +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)
 
@@ -107,8 +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 *)ocfs2_dlm_lvb(&lockres->l_lksb);
+       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);
@@ -237,6 +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,
@@ -254,6 +278,18 @@ static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
        .flags          = 0,
 };
 
+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)
 {
        return lockres->l_type == OCFS2_LOCK_TYPE_META ||
@@ -275,6 +311,19 @@ 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)
@@ -289,9 +338,16 @@ static int ocfs2_lock_create(struct ocfs2_super *osb,
                             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);
@@ -300,9 +356,14 @@ 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, _err, _lockres) do {                        \
-       mlog(ML_ERROR, "DLM error %d while calling %s on resource %s\n", \
-            _err, _func, _lockres->l_name);                            \
+#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,
@@ -311,12 +372,13 @@ 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,
@@ -365,6 +427,75 @@ 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,
@@ -384,6 +515,15 @@ static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
        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)
@@ -431,6 +571,13 @@ 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;
@@ -518,6 +665,26 @@ 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)
 {
@@ -533,6 +700,28 @@ 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();
@@ -718,8 +907,6 @@ 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
@@ -732,10 +919,120 @@ static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
                lockres->l_blocking = level;
        }
 
+       if (needs_downconvert)
+               lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
+
        mlog_exit(needs_downconvert);
        return needs_downconvert;
 }
 
+/*
+ * 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)
+{
+       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(void *opaque, int level)
 {
        struct ocfs2_lock_res *lockres = opaque;
@@ -770,14 +1067,22 @@ static void ocfs2_blocking_ast(void *opaque, int level)
 static void ocfs2_locking_ast(void *opaque)
 {
        struct ocfs2_lock_res *lockres = opaque;
+       struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
        unsigned long flags;
+       int status;
 
        spin_lock_irqsave(&lockres->l_lock, flags);
 
-       if (ocfs2_dlm_lock_status(&lockres->l_lksb)) {
+       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,
-                    ocfs2_dlm_lock_status(&lockres->l_lksb));
+                    lockres->l_name, status);
                spin_unlock_irqrestore(&lockres->l_lock, flags);
                return;
        }
@@ -800,11 +1105,23 @@ static void ocfs2_locking_ast(void *opaque)
                     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);
 }
@@ -838,6 +1155,7 @@ static int ocfs2_lock_create(struct ocfs2_super *osb,
 {
        int ret = 0;
        unsigned long flags;
+       unsigned int gen;
 
        mlog_entry_void();
 
@@ -854,6 +1172,7 @@ 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);
 
        ret = ocfs2_dlm_lock(osb->cconn,
@@ -863,6 +1182,7 @@ static int ocfs2_lock_create(struct ocfs2_super *osb,
                             lockres->l_name,
                             OCFS2_LOCK_ID_MAX_LEN - 1,
                             lockres);
+       lockres_clear_pending(lockres, gen, osb);
        if (ret) {
                ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
                ocfs2_recover_from_dlm_error(lockres, 1);
@@ -917,6 +1237,7 @@ 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)
@@ -978,16 +1299,20 @@ 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,
-                             u32 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;
        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();
 
@@ -1032,6 +1357,13 @@ 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);
@@ -1046,6 +1378,7 @@ again:
 
                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 == DLM_LOCK_IV);
@@ -1062,6 +1395,7 @@ again:
                                     lockres->l_name,
                                     OCFS2_LOCK_ID_MAX_LEN - 1,
                                     lockres);
+               lockres_clear_pending(lockres, gen, osb);
                if (ret) {
                        if (!(lkm_flags & DLM_LKF_NOQUEUE) ||
                            (ret != -EAGAIN)) {
@@ -1072,7 +1406,7 @@ again:
                        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
@@ -1112,14 +1446,39 @@ 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;
 
@@ -1128,6 +1487,10 @@ 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();
 }
 
@@ -1215,8 +1578,10 @@ 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;
 
@@ -1412,8 +1777,8 @@ 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;
@@ -1440,7 +1805,7 @@ 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;
@@ -1455,7 +1820,7 @@ 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);
 
@@ -1491,9 +1856,13 @@ 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:
@@ -1506,6 +1875,7 @@ 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;
@@ -1517,7 +1887,7 @@ 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",
@@ -1531,11 +1901,11 @@ void ocfs2_file_unlock(struct file *file)
        lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
        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;
@@ -1605,7 +1975,7 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode)
 
        mlog_entry_void();
 
-       lvb = (struct ocfs2_meta_lvb *)ocfs2_dlm_lvb(&lockres->l_lksb);
+       lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
 
        /*
         * Invalidate the LVB of a deleted inode - this way other
@@ -1657,7 +2027,7 @@ static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
 
        mlog_meta_lvb(0, lockres);
 
-       lvb = (struct ocfs2_meta_lvb *)ocfs2_dlm_lvb(&lockres->l_lksb);
+       lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
 
        /* We're safe here without the lockres lock... */
        spin_lock(&oi->ip_lock);
@@ -1692,10 +2062,10 @@ 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 *)ocfs2_dlm_lvb(&lockres->l_lksb);
+       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;
@@ -1789,7 +2159,7 @@ 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);
 
@@ -1800,8 +2170,7 @@ 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;
@@ -1809,18 +2178,14 @@ 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 "
@@ -1836,6 +2201,7 @@ 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;
@@ -1861,11 +2227,7 @@ 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);
 
@@ -1876,10 +2238,11 @@ 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, acquired;
        u32 dlm_flags;
@@ -1917,7 +2280,8 @@ int ocfs2_inode_lock_full(struct inode *inode,
        if (arg_flags & OCFS2_META_LOCK_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);
@@ -2083,6 +2447,47 @@ 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)
 {
@@ -2120,6 +2525,7 @@ int ocfs2_super_lock(struct ocfs2_super *osb,
 
                if (status < 0)
                        mlog_errno(status);
+               ocfs2_track_lock_refresh(lockres);
        }
 bail:
        mlog_exit(status);
@@ -2162,6 +2568,34 @@ void ocfs2_rename_unlock(struct ocfs2_super *osb)
                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;
@@ -2314,7 +2748,7 @@ 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;
@@ -2355,6 +2789,47 @@ static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
        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;
@@ -2480,7 +2955,8 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
        }
 
        /* for now, uuid == domain */
-       status = ocfs2_cluster_connect(osb->uuid_str,
+       status = ocfs2_cluster_connect(osb->osb_cluster_stack,
+                                      osb->uuid_str,
                                       strlen(osb->uuid_str),
                                       ocfs2_do_node_down, osb,
                                       &conn);
@@ -2494,13 +2970,15 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
                mlog_errno(status);
                mlog(ML_ERROR,
                     "could not find this host's node number\n");
-               ocfs2_cluster_disconnect(conn);
+               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->cconn = conn;
 
@@ -2516,7 +2994,8 @@ 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();
 
@@ -2535,8 +3014,10 @@ 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);
 
-       ocfs2_cluster_disconnect(osb->cconn);
+       ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
        osb->cconn = NULL;
 
        ocfs2_dlm_shutdown_debug(osb);
@@ -2555,27 +3036,12 @@ static void ocfs2_unlock_ast(void *opaque, int error)
             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 (error == -DLM_ECANCEL &&
-           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;
-       }
-
-       /* DLM_EUNLOCK is the success code for unlock */
-       if (error != -DLM_EUNLOCK) {
+       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;
        }
 
@@ -2583,6 +3049,10 @@ static void ocfs2_unlock_ast(void *opaque, int error)
        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;
@@ -2592,11 +3062,9 @@ static void ocfs2_unlock_ast(void *opaque, int error)
        }
 
        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);
+       spin_unlock_irqrestore(&lockres->l_lock, flags);
 
        mlog_exit_void();
 }
@@ -2673,11 +3141,10 @@ static int ocfs2_drop_lock(struct ocfs2_super *osb,
        if (ret) {
                ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
                mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
-               /* XXX Need to abstract this */
-               dlm_print_one_lock(lockres->l_lksb.lksb_o2dlm.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);
@@ -2689,7 +3156,7 @@ 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)
@@ -2732,6 +3199,8 @@ 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)
@@ -2768,8 +3237,8 @@ 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);
 
@@ -2787,12 +3256,14 @@ static void ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
        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;
        u32 dlm_flags = DLM_LKF_CONVERT;
@@ -2809,6 +3280,7 @@ static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
                             lockres->l_name,
                             OCFS2_LOCK_ID_MAX_LEN - 1,
                             lockres);
+       lockres_clear_pending(lockres, generation, osb);
        if (ret) {
                ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
                ocfs2_recover_from_dlm_error(lockres, 1);
@@ -2883,6 +3355,7 @@ static int ocfs2_unblock_lock(struct ocfs2_super *osb,
        int new_level;
        int ret = 0;
        int set_lvb = 0;
+       unsigned int gen;
 
        mlog_entry_void();
 
@@ -2892,6 +3365,32 @@ static int ocfs2_unblock_lock(struct ocfs2_super *osb,
 
 recheck:
        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)
+                       goto leave_requeue;
+
                ctl->requeue = 1;
                ret = ocfs2_prepare_cancel_convert(osb, lockres);
                spin_unlock_irqrestore(&lockres->l_lock, flags);
@@ -2971,9 +3470,11 @@ 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;
@@ -3027,11 +3528,11 @@ 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 != DLM_LOCK_NL && new_level != DLM_LOCK_PR);
        BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed);
@@ -3039,10 +3540,18 @@ static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
        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);
@@ -3172,6 +3681,169 @@ static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
        return UNBLOCK_CONTINUE_POST;
 }
 
+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);
+
+       ocfs2_metadata_cache_purge(&tree->rf_ci);
+
+       return UNBLOCK_CONTINUE;
+}
+
+static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres)
+{
+       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 ocfs2_qinfo_unlock(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;
+
+       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);
+}
+
 /*
  * This is the filesystem locking protocol.  It provides the lock handling
  * hooks for the underlying DLM.  It has a maximum version number.
@@ -3205,16 +3877,11 @@ static struct ocfs2_locking_protocol lproto = {
        .lp_unlock_ast          = ocfs2_unlock_ast,
 };
 
-/* This interface isn't the final one, hence the less-than-perfect names */
-void dlmglue_init_stack(void)
+void ocfs2_set_locking_protocol(void)
 {
-       o2cb_get_stack(&lproto);
+       ocfs2_stack_glue_set_locking_protocol(&lproto);
 }
 
-void dlmglue_exit_stack(void)
-{
-       o2cb_put_stack();
-}
 
 static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
                                       struct ocfs2_lock_res *lockres)