Merge tag 'v4.4.177' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.8b6.183-20190331

This is the 4.4.177 stable release

1 files changed, 14 insertions, 5 deletions

diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index 54c308e6704f..04248394843e 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -55,15 +55,17 @@ struct dm_kcopyd_client {
 	struct dm_kcopyd_throttle *throttle;
 
 /*
- * We maintain three lists of jobs:
+ * We maintain four lists of jobs:
  *
  * i)   jobs waiting for pages
  * ii)  jobs that have pages, and are waiting for the io to be issued.
- * iii) jobs that have completed.
+ * iii) jobs that don't need to do any IO and just run a callback
+ * iv) jobs that have completed.
  *
- * All three of these are protected by job_lock.
+ * All four of these are protected by job_lock.
  */
 	spinlock_t job_lock;
+	struct list_head callback_jobs;
 	struct list_head complete_jobs;
 	struct list_head io_jobs;
 	struct list_head pages_jobs;
@@ -583,6 +585,7 @@ static void do_work(struct work_struct *work)
 	struct dm_kcopyd_client *kc = container_of(work,
 					struct dm_kcopyd_client, kcopyd_work);
 	struct blk_plug plug;
+	unsigned long flags;
 
 	/*
 	 * The order that these are called is *very* important.
@@ -591,6 +594,10 @@ static void do_work(struct work_struct *work)
 	 * list.  io jobs call wake when they complete and it all
 	 * starts again.
 	 */
+	spin_lock_irqsave(&kc->job_lock, flags);
+	list_splice_tail_init(&kc->callback_jobs, &kc->complete_jobs);
+	spin_unlock_irqrestore(&kc->job_lock, flags);
+
 	blk_start_plug(&plug);
 	process_jobs(&kc->complete_jobs, kc, run_complete_job);
 	process_jobs(&kc->pages_jobs, kc, run_pages_job);
@@ -608,7 +615,7 @@ static void dispatch_job(struct kcopyd_job *job)
 	struct dm_kcopyd_client *kc = job->kc;
 	atomic_inc(&kc->nr_jobs);
 	if (unlikely(!job->source.count))
-		push(&kc->complete_jobs, job);
+		push(&kc->callback_jobs, job);
 	else if (job->pages == &zero_page_list)
 		push(&kc->io_jobs, job);
 	else
@@ -795,7 +802,7 @@ void dm_kcopyd_do_callback(void *j, int read_err, unsigned long write_err)
 	job->read_err = read_err;
 	job->write_err = write_err;
 
-	push(&kc->complete_jobs, job);
+	push(&kc->callback_jobs, job);
 	wake(kc);
 }
 EXPORT_SYMBOL(dm_kcopyd_do_callback);
@@ -825,6 +832,7 @@ struct dm_kcopyd_client *dm_kcopyd_client_create(struct dm_kcopyd_throttle *thro
 		return ERR_PTR(-ENOMEM);
 
 	spin_lock_init(&kc->job_lock);
+	INIT_LIST_HEAD(&kc->callback_jobs);
 	INIT_LIST_HEAD(&kc->complete_jobs);
 	INIT_LIST_HEAD(&kc->io_jobs);
 	INIT_LIST_HEAD(&kc->pages_jobs);
@@ -874,6 +882,7 @@ void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc)
 	/* Wait for completion of all jobs submitted by this client. */
 	wait_event(kc->destroyq, !atomic_read(&kc->nr_jobs));
 
+	BUG_ON(!list_empty(&kc->callback_jobs));
 	BUG_ON(!list_empty(&kc->complete_jobs));
 	BUG_ON(!list_empty(&kc->io_jobs));
 	BUG_ON(!list_empty(&kc->pages_jobs));