1 files changed, 22 insertions, 6 deletions

diff --git a/drivers/md/kcopyd.c b/drivers/md/kcopyd.c
index 9dcb2c8a3853..72480a48d88b 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);