ocfs2/dlm: Fix race in adding/removing lockres' to/from the tracking list

[linux-2.6-omap-h63xx.git] / fs / ocfs2 / dlm / dlmmaster.c

diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 92fd1d7d61266b64afdf6842986c0ee51e1d7e54..cbf3abe24cdb4e899184be9e72db442cb695d61a 100644 (file)
--- 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 */