2 files changed, 94 insertions, 11 deletions

diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 3f554711efe5..2f4f5d4edb07 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -180,6 +180,11 @@ struct dlm_assert_master_priv
         unsigned ignore_higher:1;
 };
 
+struct dlm_deref_lockres_priv
+{
+        struct dlm_lock_resource *deref_res;
+        u8 deref_node;
+};
 
 struct dlm_work_item
 {
@@ -191,6 +196,7 @@ struct dlm_work_item
                 struct dlm_request_all_locks_priv ral;
                 struct dlm_mig_lockres_priv ml;
                 struct dlm_assert_master_priv am;
+                struct dlm_deref_lockres_priv dl;
         } u;
 };
 
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 84f36db8ada3..77e4e6169a0d 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -102,6 +102,7 @@ static void dlm_assert_master_worker(struct dlm_work_item *item, void *data);
 static int dlm_do_assert_master(struct dlm_ctxt *dlm,
                                 struct dlm_lock_resource *res,
                                 void *nodemap, u32 flags);
+static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data);
 
 static inline int dlm_mle_equal(struct dlm_ctxt *dlm,
                                 struct dlm_master_list_entry *mle,
@@ -1717,6 +1718,11 @@ int dlm_do_assert_master(struct dlm_ctxt *dlm,
         unsigned int namelen = res->lockname.len;
 
         BUG_ON(namelen > O2NM_MAX_NAME_LEN);
+
+        spin_lock(&res->spinlock);
+        res->state |= DLM_LOCK_RES_SETREF_INPROG;
+        spin_unlock(&res->spinlock);
+
 again:
         reassert = 0;
 
@@ -1789,6 +1795,11 @@ again:
         if (reassert)
                 goto again;
 
+        spin_lock(&res->spinlock);
+        res->state &= ~DLM_LOCK_RES_SETREF_INPROG;
+        spin_unlock(&res->spinlock);
+        wake_up(&res->wq);
+
         return ret;
 }
 
@@ -2296,6 +2307,9 @@ int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
         int ret = -EINVAL;
         u8 node;
         unsigned int hash;
+        struct dlm_work_item *item;
+        int cleared = 0;
+        int dispatch = 0;
 
         if (!dlm_grab(dlm))
                 return 0;
@@ -2326,27 +2340,90 @@ int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
         spin_unlock(&dlm->spinlock);
 
         spin_lock(&res->spinlock);
-        BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
-        if (test_bit(node, res->refmap)) {
-                ret = 0;
-                dlm_lockres_clear_refmap_bit(node, res);
-        } else {
-                mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
-                     "but it is already dropped!\n", dlm->name, namelen,
-                     name, node);
-                __dlm_print_one_lock_resource(res);
+        if (res->state & DLM_LOCK_RES_SETREF_INPROG)
+                dispatch = 1;
+        else {
+                BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
+                if (test_bit(node, res->refmap)) {
+                        dlm_lockres_clear_refmap_bit(node, res);
+                        cleared = 1;
+                }
         }
         spin_unlock(&res->spinlock);
 
-        if (!ret)
-                dlm_lockres_calc_usage(dlm, res);
+        if (!dispatch) {
+                if (cleared)
+                        dlm_lockres_calc_usage(dlm, res);
+                else {
+                        mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
+                        "but it is already dropped!\n", dlm->name,
+                        res->lockname.len, res->lockname.name, node);
+                        __dlm_print_one_lock_resource(res);
+                }
+                ret = 0;
+                goto done;
+        }
+
+        item = kzalloc(sizeof(*item), GFP_NOFS);
+        if (!item) {
+                ret = -ENOMEM;
+                mlog_errno(ret);
+                goto done;
+        }
+
+        dlm_init_work_item(dlm, item, dlm_deref_lockres_worker, NULL);
+        item->u.dl.deref_res = res;
+        item->u.dl.deref_node = node;
+
+        spin_lock(&dlm->work_lock);
+        list_add_tail(&item->list, &dlm->work_list);
+        spin_unlock(&dlm->work_lock);
+
+        queue_work(dlm->dlm_worker, &dlm->dispatched_work);
+        return 0;
+
 done:
         if (res)
                 dlm_lockres_put(res);
         dlm_put(dlm);
+
         return ret;
 }
 
+static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
+{
+        struct dlm_ctxt *dlm;
+        struct dlm_lock_resource *res;
+        u8 node;
+        u8 cleared = 0;
+
+        dlm = item->dlm;
+        res = item->u.dl.deref_res;
+        node = item->u.dl.deref_node;
+
+        spin_lock(&res->spinlock);
+        BUG_ON(res->state & DLM_LOCK_RES_DROPPING_REF);
+        if (test_bit(node, res->refmap)) {
+                __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG);
+                dlm_lockres_clear_refmap_bit(node, res);
+                cleared = 1;
+        }
+        spin_unlock(&res->spinlock);
+
+        if (cleared) {
+                mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
+                     dlm->name, res->lockname.len, res->lockname.name, node);
+                dlm_lockres_calc_usage(dlm, res);
+        } else {
+                mlog(ML_ERROR, "%s:%.*s: node %u trying to drop ref "
+                     "but it is already dropped!\n", dlm->name,
+                     res->lockname.len, res->lockname.name, node);
+                __dlm_print_one_lock_resource(res);
+        }
+
+        dlm_lockres_put(res);
+}
+
 
 /*
  * DLM_MIGRATE_LOCKRES