Merge tag 'dm-4.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - various fixes and cleanups for request-based DM core

 - add support for delaying the requeue of requests; used by DM
   multipath when all paths have failed and 'queue_if_no_path' is
   enabled

 - DM cache improvements to speedup the loading metadata and the writing
   of the hint array

 - fix potential for a dm-crypt crash on device teardown

 - remove dm_bufio_cond_resched() and just using cond_resched()

 - change DM multipath to return a reservation conflict error
   immediately; rather than failing the path and retrying (potentially
   indefinitely)

* tag 'dm-4.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (24 commits)
  dm mpath: always return reservation conflict without failing over
  dm bufio: remove dm_bufio_cond_resched()
  dm crypt: fix crash on exit
  dm cache metadata: switch to using the new cursor api for loading metadata
  dm array: introduce cursor api
  dm btree: introduce cursor api
  dm cache policy smq: distribute entries to random levels when switching to smq
  dm cache: speed up writing of the hint array
  dm array: add dm_array_new()
  dm mpath: delay the requeue of blk-mq requests while all paths down
  dm mpath: use dm_mq_kick_requeue_list()
  dm rq: introduce dm_mq_kick_requeue_list()
  dm rq: reduce arguments passed to map_request() and dm_requeue_original_request()
  dm rq: add DM_MAPIO_DELAY_REQUEUE to delay requeue of blk-mq requests
  dm: convert wait loops to use autoremove_wake_function()
  dm: use signal_pending_state() in dm_wait_for_completion()
  dm: rename task state function arguments
  dm: add two lockdep_assert_held() statements
  dm rq: simplify dm_old_stop_queue()
  dm mpath: check if path's request_queue is dying in activate_path()
  ...

1 files changed, 10 insertions, 14 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 0448e7e35c8c..a2768835d394 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -113,8 +113,7 @@ struct iv_tcw_private {
  * and encrypts / decrypts at the same time.
  */
 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
-	     DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
-	     DM_CRYPT_EXIT_THREAD};
+	     DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD };
 
 /*
  * The fields in here must be read only after initialization.
@@ -1207,18 +1206,20 @@ continue_locked:
 		if (!RB_EMPTY_ROOT(&cc->write_tree))
 			goto pop_from_list;
 
-		if (unlikely(test_bit(DM_CRYPT_EXIT_THREAD, &cc->flags))) {
-			spin_unlock_irq(&cc->write_thread_wait.lock);
-			break;
-		}
-
-		__set_current_state(TASK_INTERRUPTIBLE);
+		set_current_state(TASK_INTERRUPTIBLE);
 		__add_wait_queue(&cc->write_thread_wait, &wait);
 
 		spin_unlock_irq(&cc->write_thread_wait.lock);
 
+		if (unlikely(kthread_should_stop())) {
+			set_task_state(current, TASK_RUNNING);
+			remove_wait_queue(&cc->write_thread_wait, &wait);
+			break;
+		}
+
 		schedule();
 
+		set_task_state(current, TASK_RUNNING);
 		spin_lock_irq(&cc->write_thread_wait.lock);
 		__remove_wait_queue(&cc->write_thread_wait, &wait);
 		goto continue_locked;
@@ -1533,13 +1534,8 @@ static void crypt_dtr(struct dm_target *ti)
 	if (!cc)
 		return;
 
-	if (cc->write_thread) {
-		spin_lock_irq(&cc->write_thread_wait.lock);
-		set_bit(DM_CRYPT_EXIT_THREAD, &cc->flags);
-		wake_up_locked(&cc->write_thread_wait);
-		spin_unlock_irq(&cc->write_thread_wait.lock);
+	if (cc->write_thread)
 		kthread_stop(cc->write_thread);
-	}
 
 	if (cc->io_queue)
 		destroy_workqueue(cc->io_queue);