1 files changed, 22 insertions, 6 deletions

diff --git a/drivers/md/kcopyd.c b/drivers/md/kcopyd.c
index 9dcb2c8..72480a4 100644
--- a/drivers/md/kcopyd.c
+++ b/drivers/md/kcopyd.c
@@ -22,6 +22,7 @@
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/workqueue.h>
+#include <linux/mutex.h>
 
 #include "kcopyd.h"
 
@@ -44,6 +45,9 @@ struct kcopyd_client {
 	struct page_list *pages;
 	unsigned int nr_pages;
 	unsigned int nr_free_pages;
+
+	wait_queue_head_t destroyq;
+	atomic_t nr_jobs;
 };
 
 static struct page_list *alloc_pl(void)
@@ -292,10 +296,15 @@ static int run_complete_job(struct kcopyd_job *job)
 	int read_err = job->read_err;
 	unsigned int write_err = job->write_err;
 	kcopyd_notify_fn fn = job->fn;
+	struct kcopyd_client *kc = job->kc;
 
-	kcopyd_put_pages(job->kc, job->pages);
+	kcopyd_put_pages(kc, job->pages);
 	mempool_free(job, _job_pool);
 	fn(read_err, write_err, context);
+
+	if (atomic_dec_and_test(&kc->nr_jobs))
+		wake_up(&kc->destroyq);
+
 	return 0;
 }
 
@@ -430,6 +439,7 @@ static void do_work(void *ignored)
  */
 static void dispatch_job(struct kcopyd_job *job)
 {
+	atomic_inc(&job->kc->nr_jobs);
 	push(&_pages_jobs, job);
 	wake();
 }
@@ -572,21 +582,21 @@ int kcopyd_cancel(struct kcopyd_job *job, int block)
 /*-----------------------------------------------------------------
  * Unit setup
  *---------------------------------------------------------------*/
-static DECLARE_MUTEX(_client_lock);
+static DEFINE_MUTEX(_client_lock);
 static LIST_HEAD(_clients);
 
 static void client_add(struct kcopyd_client *kc)
 {
-	down(&_client_lock);
+	mutex_lock(&_client_lock);
 	list_add(&kc->list, &_clients);
-	up(&_client_lock);
+	mutex_unlock(&_client_lock);
 }
 
 static void client_del(struct kcopyd_client *kc)
 {
-	down(&_client_lock);
+	mutex_lock(&_client_lock);
 	list_del(&kc->list);
-	up(&_client_lock);
+	mutex_unlock(&_client_lock);
 }
 
 static DEFINE_MUTEX(kcopyd_init_lock);
@@ -669,6 +679,9 @@ int kcopyd_client_create(unsigned int nr_pages, struct kcopyd_client **result)
 		return r;
 	}
 
+	init_waitqueue_head(&kc->destroyq);
+	atomic_set(&kc->nr_jobs, 0);
+
 	client_add(kc);
 	*result = kc;
 	return 0;
@@ -676,6 +689,9 @@ int kcopyd_client_create(unsigned int nr_pages, struct kcopyd_client **result)
 
 void kcopyd_client_destroy(struct kcopyd_client *kc)
 {
+	/* Wait for completion of all jobs submitted by this client. */
+	wait_event(kc->destroyq, !atomic_read(&kc->nr_jobs));
+
 	dm_io_put(kc->nr_pages);
 	client_free_pages(kc);
 	client_del(kc);