From: Alexander Aring <aahringo@redhat.com> stable inclusion from stable-v5.10.150 commit 0b2d8e4db40c44d4bfe7c8819888f6299f7c0a54 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0XA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit eef6ec9bf390e836a6c4029f3620fe49528aa1fe upstream. This patch fixes a race by using ls_cb_mutex around the bit operations and conditional code blocks for LSFL_CB_DELAY. The function dlm_callback_stop() expects to stop all callbacks and flush all currently queued onces. The set_bit() is not enough because there can still be queue_work() after the workqueue was flushed. To avoid queue_work() after set_bit(), surround both by ls_cb_mutex. Cc: stable@vger.kernel.org Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com> --- fs/dlm/ast.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c index 283c7b94edda..ca06069e95c8 100644 --- a/fs/dlm/ast.c +++ b/fs/dlm/ast.c @@ -198,13 +198,13 @@ void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status, if (!prev_seq) { kref_get(&lkb->lkb_ref); + mutex_lock(&ls->ls_cb_mutex); if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) { - mutex_lock(&ls->ls_cb_mutex); list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay); - mutex_unlock(&ls->ls_cb_mutex); } else { queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work); } + mutex_unlock(&ls->ls_cb_mutex); } out: mutex_unlock(&lkb->lkb_cb_mutex); @@ -284,7 +284,9 @@ void dlm_callback_stop(struct dlm_ls *ls) void dlm_callback_suspend(struct dlm_ls *ls) { + mutex_lock(&ls->ls_cb_mutex); set_bit(LSFL_CB_DELAY, &ls->ls_flags); + mutex_unlock(&ls->ls_cb_mutex); if (ls->ls_callback_wq) flush_workqueue(ls->ls_callback_wq); -- 2.25.1