From 1e5895816030eaadb952c89eb9f4054e5c0082c3 Mon Sep 17 00:00:00 2001 From: Joseph Qi Date: Thu, 18 Dec 2014 16:17:34 -0800 Subject: [PATCH] ocfs2/dlm: fix race between dispatched_work and dlm_lockres_grab_inflight_worker Commit ac4fef4d23ed ("ocfs2/dlm: do not purge lockres that is queued for assert master") may have the following possible race case: dlm_dispatch_assert_master dlm_wq ======================================================================== queue_work(dlm->quedlm_worker, &dlm->dispatched_work); dispatch work, dlm_lockres_drop_inflight_worker *BUG_ON(res->inflight_assert_workers == 0)* dlm_lockres_grab_inflight_worker inflight_assert_workers++ So ensure inflight_assert_workers to be increased first. Signed-off-by: Joseph Qi Signed-off-by: Xue jiufei Cc: Joel Becker Reviewed-by: Mark Fasheh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/dlm/dlmmaster.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c index 3689b3592042..a6944b25fd5b 100644 --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -695,14 +695,6 @@ void __dlm_lockres_grab_inflight_worker(struct dlm_ctxt *dlm, res->inflight_assert_workers); } -static void dlm_lockres_grab_inflight_worker(struct dlm_ctxt *dlm, - struct dlm_lock_resource *res) -{ - spin_lock(&res->spinlock); - __dlm_lockres_grab_inflight_worker(dlm, res); - spin_unlock(&res->spinlock); -} - static void __dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) { @@ -1646,6 +1638,7 @@ send_response: } mlog(0, "%u is the owner of %.*s, cleaning everyone else\n", dlm->node_num, res->lockname.len, res->lockname.name); + spin_lock(&res->spinlock); ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx, DLM_ASSERT_MASTER_MLE_CLEANUP); if (ret < 0) { @@ -1653,7 +1646,8 @@ send_response: response = DLM_MASTER_RESP_ERROR; dlm_lockres_put(res); } else - dlm_lockres_grab_inflight_worker(dlm, res); + __dlm_lockres_grab_inflight_worker(dlm, res); + spin_unlock(&res->spinlock); } else { if (res) dlm_lockres_put(res); -- 2.39.5