UPSTREAM: workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes The workqueue code added manual lock acquisition annotations to catch deadlocks. After lockdepcrossrelease was introduced, some of those became redundant, since wait_for_completion() already does the acquisition and tracking. Remove the duplicate annotations. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-9-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org> (cherry picked from commit fd1a5b04dfb899f84ddeb8acdaea6b98283df1e5) Signed-off-by: Xuewei Zhang <xueweiz@google.com> BUG=b:112611854 TEST=xfstests generic/113 Change-Id: Ice24050ea02b961b3a592fdacb58a89ee97a65d9 Reviewed-on: https://chromium-review.googlesource.com/1195022 Commit-Ready: Xuewei Zhang <xueweiz@google.com> Tested-by: Xuewei Zhang <xueweiz@google.com> Reviewed-by: Guenter Roeck <groeck@chromium.org>
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 1c527ab..33eaaf0 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h
@@ -219,7 +219,7 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; } \ __init_work((_work), _onstack); \ (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \ - lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \ + lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \ INIT_LIST_HEAD(&(_work)->entry); \ (_work)->func = (_func); \ } while (0) @@ -399,7 +399,7 @@ __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active, static struct lock_class_key __key; \ const char *__lock_name; \ \ - __lock_name = #fmt#args; \ + __lock_name = "(wq_completion)"#fmt#args; \ \ __alloc_workqueue_key((fmt), (flags), (max_active), \ &__key, __lock_name, ##args); \
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index d8a7f89..98055b2 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c
@@ -2492,15 +2492,8 @@ static void insert_wq_barrier(struct pool_workqueue *pwq, INIT_WORK_ONSTACK(&barr->work, wq_barrier_func); __set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(&barr->work)); - /* - * Explicitly init the crosslock for wq_barrier::done, make its lock - * key a subkey of the corresponding work. As a result we won't - * build a dependency between wq_barrier::done and unrelated work. - */ - lockdep_init_map_crosslock((struct lockdep_map *)&barr->done.map, - "(complete)wq_barr::done", - target->lockdep_map.key, 1); - __init_completion(&barr->done); + init_completion_map(&barr->done, &target->lockdep_map); + barr->task = current; /* @@ -2606,16 +2599,13 @@ void flush_workqueue(struct workqueue_struct *wq) struct wq_flusher this_flusher = { .list = LIST_HEAD_INIT(this_flusher.list), .flush_color = -1, - .done = COMPLETION_INITIALIZER_ONSTACK(this_flusher.done), + .done = COMPLETION_INITIALIZER_ONSTACK_MAP(this_flusher.done, wq->lockdep_map), }; int next_color; if (WARN_ON(!wq_online)) return; - lock_map_acquire(&wq->lockdep_map); - lock_map_release(&wq->lockdep_map); - mutex_lock(&wq->mutex); /* @@ -2878,9 +2868,6 @@ bool flush_work(struct work_struct *work) if (WARN_ON(!wq_online)) return false; - lock_map_acquire(&work->lockdep_map); - lock_map_release(&work->lockdep_map); - if (start_flush_work(work, &barr)) { wait_for_completion(&barr.done); destroy_work_on_stack(&barr.work);