workqueue: skip lockdep wq dependency in cancel_work_sync()
In cancel_work_sync(), we can only have one of two cases, even with an ordered workqueue: * the work isn't running, just cancelled before it started * the work is running, but then nothing else can be on the workqueue before it Thus, we need to skip the lockdep workqueue dependency handling, otherwise we get false positive reports from lockdep saying that we have a potential deadlock when the workqueue also has other work items with locking, e.g. work1_function() { mutex_lock(&mutex); ... } work2_function() { /* nothing */ } other_function() { queue_work(ordered_wq, &work1); queue_work(ordered_wq, &work2); mutex_lock(&mutex); cancel_work_sync(&work2); } As described above, this isn't a problem, but lockdep will currently flag it as if cancel_work_sync() was flush_work(), which *is* a problem. Signed-off-by:Johannes Berg <johannes.berg@intel.com> Signed-off-by:
Tejun Heo <tj@kernel.org>
parent
66448bc2