4 files changed, 38 insertions, 29 deletions

diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index d5a86fb81a49..bb53714813ab 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -140,6 +140,7 @@ struct dlm_ctxt
         unsigned int purge_count;
         spinlock_t spinlock;
         spinlock_t ast_lock;
+        spinlock_t track_lock;
         char *name;
         u8 node_num;
         u32 key;
@@ -316,6 +317,8 @@ struct dlm_lock_resource
          * put on a list for the dlm thread to run. */
         unsigned long    last_used;
 
+        struct dlm_ctxt *dlm;
+
         unsigned migration_pending:1;
         atomic_t asts_reserved;
         spinlock_t spinlock;
diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c
index 1b81dcba175d..b32f60a5acfb 100644
--- a/fs/ocfs2/dlm/dlmdebug.c
+++ b/fs/ocfs2/dlm/dlmdebug.c
@@ -630,43 +630,38 @@ static void *lockres_seq_start(struct seq_file *m, loff_t *pos)
 {
         struct debug_lockres *dl = m->private;
         struct dlm_ctxt *dlm = dl->dl_ctxt;
+        struct dlm_lock_resource *oldres = dl->dl_res;
         struct dlm_lock_resource *res = NULL;
+        struct list_head *track_list;
 
-        spin_lock(&dlm->spinlock);
+        spin_lock(&dlm->track_lock);
+        if (oldres)
+                track_list = &oldres->tracking;
+        else
+                track_list = &dlm->tracking_list;
 
-        if (dl->dl_res) {
-                list_for_each_entry(res, &dl->dl_res->tracking, tracking) {
-                        if (dl->dl_res) {
-                                dlm_lockres_put(dl->dl_res);
-                                dl->dl_res = NULL;
-                        }
-                        if (&res->tracking == &dlm->tracking_list) {
-                                mlog(0, "End of list found, %p\n", res);
-                                dl = NULL;
-                                break;
-                        }
+        list_for_each_entry(res, track_list, tracking) {
+                if (&res->tracking == &dlm->tracking_list)
+                        res = NULL;
+                else
                         dlm_lockres_get(res);
-                        dl->dl_res = res;
-                        break;
-                }
-        } else {
-                if (!list_empty(&dlm->tracking_list)) {
-                        list_for_each_entry(res, &dlm->tracking_list, tracking)
-                                break;
-                        dlm_lockres_get(res);
-                        dl->dl_res = res;
-                } else
-                        dl = NULL;
+                break;
         }
+        spin_unlock(&dlm->track_lock);
 
-        if (dl) {
-                spin_lock(&dl->dl_res->spinlock);
-                dump_lockres(dl->dl_res, dl->dl_buf, dl->dl_len - 1);
-                spin_unlock(&dl->dl_res->spinlock);
-        }
+        if (oldres)
+                dlm_lockres_put(oldres);
 
-        spin_unlock(&dlm->spinlock);
+        dl->dl_res = res;
+
+        if (res) {
+                spin_lock(&res->spinlock);
+                dump_lockres(res, dl->dl_buf, dl->dl_len - 1);
+                spin_unlock(&res->spinlock);
+        } else
+                dl = NULL;
 
+        /* passed to seq_show */
         return dl;
 }
 
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 63f8125824e8..d8d578f45613 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -1550,6 +1550,7 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
         spin_lock_init(&dlm->spinlock);
         spin_lock_init(&dlm->master_lock);
         spin_lock_init(&dlm->ast_lock);
+        spin_lock_init(&dlm->track_lock);
         INIT_LIST_HEAD(&dlm->list);
         INIT_LIST_HEAD(&dlm->dirty_list);
         INIT_LIST_HEAD(&dlm->reco.resources);
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 92fd1d7d6126..cbf3abe24cdb 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -505,8 +505,10 @@ void dlm_change_lockres_owner(struct dlm_ctxt *dlm,
 static void dlm_lockres_release(struct kref *kref)
 {
         struct dlm_lock_resource *res;
+        struct dlm_ctxt *dlm;
 
         res = container_of(kref, struct dlm_lock_resource, refs);
+        dlm = res->dlm;
 
         /* This should not happen -- all lockres' have a name
          * associated with them at init time. */
@@ -515,6 +517,7 @@ static void dlm_lockres_release(struct kref *kref)
         mlog(0, "destroying lockres %.*s\n", res->lockname.len,
              res->lockname.name);
 
+        spin_lock(&dlm->track_lock);
         if (!list_empty(&res->tracking))
                 list_del_init(&res->tracking);
         else {
@@ -522,6 +525,9 @@ static void dlm_lockres_release(struct kref *kref)
                      res->lockname.len, res->lockname.name);
                 dlm_print_one_lock_resource(res);
         }
+        spin_unlock(&dlm->track_lock);
+
+        dlm_put(dlm);
 
         if (!hlist_unhashed(&res->hash_node) ||
             !list_empty(&res->granted) ||
@@ -595,6 +601,10 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
         res->migration_pending = 0;
         res->inflight_locks = 0;
 
+        /* put in dlm_lockres_release */
+        dlm_grab(dlm);
+        res->dlm = dlm;
+
         kref_init(&res->refs);
 
         /* just for consistency */