dm kcopyd: remove redundant client counting

[firefly-linux-kernel-4.4.55.git] / drivers / md / kcopyd.c

diff --git a/drivers/md/kcopyd.c b/drivers/md/kcopyd.c
index 0b2907d59a3f7190c7e2094c2e718a3700918bf8..17345844b03eb92c5b8a86d1eabc980b8869fed7 100644 (file)
--- a/drivers/md/kcopyd.c
+++ b/drivers/md/kcopyd.c
@@ -31,8 +31,6 @@
  * pages for kcopyd io.
  *---------------------------------------------------------------*/
 struct dm_kcopyd_client {
-       struct list_head list;
-
        spinlock_t lock;
        struct page_list *pages;
        unsigned int nr_pages;
@@ -224,7 +222,7 @@ struct kcopyd_job {
 
 static struct kmem_cache *_job_cache;
 
-static int jobs_init(void)
+int __init dm_kcopyd_init(void)
 {
        _job_cache = KMEM_CACHE(kcopyd_job, 0);
        if (!_job_cache)
@@ -233,7 +231,7 @@ static int jobs_init(void)
        return 0;
 }
 
-static void jobs_exit(void)
+void dm_kcopyd_exit(void)
 {
        kmem_cache_destroy(_job_cache);
        _job_cache = NULL;
@@ -581,78 +579,17 @@ int kcopyd_cancel(struct kcopyd_job *job, int block)
 #endif  /*  0  */
 
 /*-----------------------------------------------------------------
- * Unit setup
+ * Client setup
  *---------------------------------------------------------------*/
-static DEFINE_MUTEX(_client_lock);
-static LIST_HEAD(_clients);
-
-static void client_add(struct dm_kcopyd_client *kc)
-{
-       mutex_lock(&_client_lock);
-       list_add(&kc->list, &_clients);
-       mutex_unlock(&_client_lock);
-}
-
-static void client_del(struct dm_kcopyd_client *kc)
-{
-       mutex_lock(&_client_lock);
-       list_del(&kc->list);
-       mutex_unlock(&_client_lock);
-}
-
-static DEFINE_MUTEX(kcopyd_init_lock);
-static int kcopyd_clients = 0;
-
-static int kcopyd_init(void)
-{
-       int r;
-
-       mutex_lock(&kcopyd_init_lock);
-
-       if (kcopyd_clients) {
-               /* Already initialized. */
-               kcopyd_clients++;
-               mutex_unlock(&kcopyd_init_lock);
-               return 0;
-       }
-
-       r = jobs_init();
-       if (r) {
-               mutex_unlock(&kcopyd_init_lock);
-               return r;
-       }
-
-       kcopyd_clients++;
-       mutex_unlock(&kcopyd_init_lock);
-       return 0;
-}
-
-static void kcopyd_exit(void)
-{
-       mutex_lock(&kcopyd_init_lock);
-       kcopyd_clients--;
-       if (!kcopyd_clients) {
-               jobs_exit();
-       }
-       mutex_unlock(&kcopyd_init_lock);
-}
-
 int dm_kcopyd_client_create(unsigned int nr_pages,
                            struct dm_kcopyd_client **result)
 {
-       int r = 0;
+       int r = -ENOMEM;
        struct dm_kcopyd_client *kc;
 
-       r = kcopyd_init();
-       if (r)
-               return r;
-
        kc = kmalloc(sizeof(*kc), GFP_KERNEL);
-       if (!kc) {
-               r = -ENOMEM;
-               kcopyd_exit();
-               return r;
-       }
+       if (!kc)
+               return -ENOMEM;
 
        spin_lock_init(&kc->lock);
        spin_lock_init(&kc->job_lock);
@@ -661,51 +598,42 @@ int dm_kcopyd_client_create(unsigned int nr_pages,
        INIT_LIST_HEAD(&kc->pages_jobs);
 
        kc->job_pool = mempool_create_slab_pool(MIN_JOBS, _job_cache);
-       if (!kc->job_pool) {
-               r = -ENOMEM;
-               kfree(kc);
-               kcopyd_exit();
-               return r;
-       }
+       if (!kc->job_pool)
+               goto bad_slab;
 
        INIT_WORK(&kc->kcopyd_work, do_work);
        kc->kcopyd_wq = create_singlethread_workqueue("kcopyd");
-       if (!kc->kcopyd_wq) {
-               r = -ENOMEM;
-               mempool_destroy(kc->job_pool);
-               kfree(kc);
-               kcopyd_exit();
-               return r;
-       }
+       if (!kc->kcopyd_wq)
+               goto bad_workqueue;
 
        kc->pages = NULL;
        kc->nr_pages = kc->nr_free_pages = 0;
        r = client_alloc_pages(kc, nr_pages);
-       if (r) {
-               destroy_workqueue(kc->kcopyd_wq);
-               mempool_destroy(kc->job_pool);
-               kfree(kc);
-               kcopyd_exit();
-               return r;
-       }
+       if (r)
+               goto bad_client_pages;
 
        kc->io_client = dm_io_client_create(nr_pages);
        if (IS_ERR(kc->io_client)) {
                r = PTR_ERR(kc->io_client);
-               client_free_pages(kc);
-               destroy_workqueue(kc->kcopyd_wq);
-               mempool_destroy(kc->job_pool);
-               kfree(kc);
-               kcopyd_exit();
-               return r;
+               goto bad_io_client;
        }
 
        init_waitqueue_head(&kc->destroyq);
        atomic_set(&kc->nr_jobs, 0);
 
-       client_add(kc);
        *result = kc;
        return 0;
+
+bad_io_client:
+       client_free_pages(kc);
+bad_client_pages:
+       destroy_workqueue(kc->kcopyd_wq);
+bad_workqueue:
+       mempool_destroy(kc->job_pool);
+bad_slab:
+       kfree(kc);
+
+       return r;
 }
 EXPORT_SYMBOL(dm_kcopyd_client_create);
 
@@ -720,9 +648,7 @@ void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc)
        destroy_workqueue(kc->kcopyd_wq);
        dm_io_client_destroy(kc->io_client);
        client_free_pages(kc);
-       client_del(kc);
        mempool_destroy(kc->job_pool);
        kfree(kc);
-       kcopyd_exit();
 }
 EXPORT_SYMBOL(dm_kcopyd_client_destroy);