ocfs2: dlm recovery / lockres reference count fix

Take a reference on lockres structures while they are on the recovery list.

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

3 files changed, 15 insertions, 4 deletions

diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index bf873919b009..9e052445b0b5 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -849,6 +849,7 @@ void dlm_clean_master_list(struct dlm_ctxt *dlm,
                            u8 dead_node);
 int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock);
 
+int __dlm_lockres_unused(struct dlm_lock_resource *res);
 
 static inline const char * dlm_lock_mode_name(int mode)
 {
diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 81bd2400e221..6ee8b3247129 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -1758,8 +1758,14 @@ void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
         struct dlm_lock *lock;
 
         res->state |= DLM_LOCK_RES_RECOVERING;
-        if (!list_empty(&res->recovering))
+        if (!list_empty(&res->recovering)) {
+                mlog(0,
+                     "Recovering res %s:%.*s, is already on recovery list!\n",
+                     dlm->name, res->lockname.len, res->lockname.name);
                 list_del_init(&res->recovering);
+        }
+        /* We need to hold a reference while on the recovery list */
+        dlm_lockres_get(res);
         list_add_tail(&res->recovering, &dlm->reco.resources);
 
         /* find any pending locks and put them back on proper list */
@@ -1848,9 +1854,11 @@ static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
                         spin_lock(&res->spinlock);
                         dlm_change_lockres_owner(dlm, res, new_master);
                         res->state &= ~DLM_LOCK_RES_RECOVERING;
-                        __dlm_dirty_lockres(dlm, res);
+                        if (!__dlm_lockres_unused(res))
+                                __dlm_dirty_lockres(dlm, res);
                         spin_unlock(&res->spinlock);
                         wake_up(&res->wq);
+                        dlm_lockres_put(res);
                 }
         }
 
@@ -1883,11 +1891,13 @@ static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
                                              dlm->name, res->lockname.len,
                                              res->lockname.name, res->owner);
                                         list_del_init(&res->recovering);
+                                        dlm_lockres_put(res);
                                 }
                                 spin_lock(&res->spinlock);
                                 dlm_change_lockres_owner(dlm, res, new_master);
                                 res->state &= ~DLM_LOCK_RES_RECOVERING;
-                                __dlm_dirty_lockres(dlm, res);
+                                if (!__dlm_lockres_unused(res))
+                                        __dlm_dirty_lockres(dlm, res);
                                 spin_unlock(&res->spinlock);
                                 wake_up(&res->wq);
                         }
diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
index 22bb58a514df..71302b90daf5 100644
--- a/fs/ocfs2/dlm/dlmthread.c
+++ b/fs/ocfs2/dlm/dlmthread.c
@@ -81,7 +81,7 @@ repeat:
 }
 
 
-static int __dlm_lockres_unused(struct dlm_lock_resource *res)
+int __dlm_lockres_unused(struct dlm_lock_resource *res)
 {
         if (list_empty(&res->granted) &&
             list_empty(&res->converting) &&