From: Wengang Wang Date: Fri, 30 Jul 2010 15:18:00 +0000 (+0800) Subject: ocfs2/dlm: remove potential deadlock -V3 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b11f1f1ab73fd358b1b734a9427744802202ba68;p=linux-beck.git ocfs2/dlm: remove potential deadlock -V3 When we need to take both dlm_domain_lock and dlm->spinlock, we should take them in order of: dlm_domain_lock then dlm->spinlock. There is pathes disobey this order. That is calling dlm_lockres_put() with dlm->spinlock held in dlm_run_purge_list. dlm_lockres_put() calls dlm_put() at the ref and dlm_put() locks on dlm_domain_lock. Fix: Don't grab/put the dlm when the initialising/releasing lockres. That grab is not required because we don't call dlm_unregister_domain() based on refcount. Signed-off-by: Wengang Wang Cc: stable@kernel.org Signed-off-by: Joel Becker --- diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c index 6d098b89d46e..ffb4c68dafa4 100644 --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -511,8 +511,6 @@ static void dlm_lockres_release(struct kref *kref) atomic_dec(&dlm->res_cur_count); - dlm_put(dlm); - if (!hlist_unhashed(&res->hash_node) || !list_empty(&res->granted) || !list_empty(&res->converting) || @@ -585,8 +583,6 @@ 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);