Merge pull request #125 from arutk/vol_ref_cnt

Wait for IO put in volume close

src/ocf_io.c

@@ -54,10 +54,15 @@ struct ocf_io *ocf_io_new(ocf_volume_t volume)
 	struct ocf_io_meta *io_meta;
 	void *data;
 
-	data = env_allocator_new(volume->type->allocator);
-	if (!data)
+	if (!ocf_refcnt_inc(&volume->refcnt))
 		return NULL;
 
+	data = env_allocator_new(volume->type->allocator);
+	if (!data) {
+		ocf_refcnt_dec(&volume->refcnt);
+		return NULL;
+	}
+
 	io = data + sizeof(struct ocf_io_meta);
 
 	io_meta = ocf_io_get_meta(io);
@@ -92,6 +97,8 @@ void ocf_io_put(struct ocf_io *io)
 	if (env_atomic_dec_return(&io_meta->ref_count))
 		return;
 
+	ocf_refcnt_dec(&io->volume->refcnt);
+
 	env_allocator_del(io->volume->type->allocator,
 			(void *)io - sizeof(struct ocf_io_meta));
 }

src/ocf_volume.c

@@ -79,6 +79,9 @@ int ocf_volume_init(ocf_volume_t volume, ocf_volume_type_t type,
 	if (!volume->priv)
 		return -OCF_ERR_NO_MEM;
 
+	ocf_refcnt_init(&volume->refcnt);
+	ocf_refcnt_freeze(&volume->refcnt);
+
 	if (!uuid) {
 		volume->uuid.size = 0;
 		volume->uuid.data = NULL;
@@ -109,6 +112,7 @@ int ocf_volume_init(ocf_volume_t volume, ocf_volume_type_t type,
 	return 0;
 
 err:
+	ocf_refcnt_unfreeze(&volume->refcnt);
 	env_free(volume->priv);
 	return -OCF_ERR_NO_MEM;
 }
@@ -137,6 +141,7 @@ void ocf_volume_move(ocf_volume_t volume, ocf_volume_t from)
 	volume->priv = from->priv;
 	volume->cache = from->cache;
 	volume->features = from->features;
+	volume->refcnt = from->refcnt;
 
 	/*
 	 * Deinitialize original volume without freeing resources.
@@ -221,9 +226,6 @@ int ocf_volume_is_atomic(ocf_volume_t volume)
 
 struct ocf_io *ocf_volume_new_io(ocf_volume_t volume)
 {
-	if (!volume->opened)
-		return NULL;
-
 	return ocf_io_new(volume);
 }
 
@@ -276,16 +278,32 @@ int ocf_volume_open(ocf_volume_t volume, void *volume_params)
 	if (ret)
 		return ret;
 
+	ocf_refcnt_unfreeze(&volume->refcnt);
 	volume->opened = true;
 
 	return 0;
 }
 
+static void ocf_volume_close_end(void *ctx)
+{
+	env_completion *cmpl = ctx;
+
+	env_completion_complete(cmpl);
+}
+
 void ocf_volume_close(ocf_volume_t volume)
 {
+	env_completion cmpl;
+
 	ENV_BUG_ON(!volume->type->properties->ops.close);
 	ENV_BUG_ON(!volume->opened);
 
+	env_completion_init(&cmpl);
+	ocf_refcnt_freeze(&volume->refcnt);
+	ocf_refcnt_register_zero_cb(&volume->refcnt, ocf_volume_close_end,
+			&cmpl);
+	env_completion_wait(&cmpl);
+
 	volume->type->properties->ops.close(volume);
 	volume->opened = false;
 }

src/ocf_volume_priv.h

@@ -8,6 +8,7 @@
 
 #include "ocf_env.h"
 #include "ocf_io_priv.h"
+#include "utils/utils_refcnt.h"
 
 struct ocf_volume_type {
 	const struct ocf_volume_properties *properties;
@@ -26,6 +27,7 @@ struct ocf_volume {
 		unsigned discard_zeroes:1;
 			/* true if reading discarded pages returns 0 */
 	} features;
+	struct ocf_refcnt refcnt;
 };
 
 int ocf_volume_type_init(struct ocf_volume_type **type,

src/utils/utils_refcnt.c

@@ -5,6 +5,14 @@
 
 #include "../utils/utils_refcnt.h"
 
+void ocf_refcnt_init(struct ocf_refcnt *rc)
+{
+	env_atomic_set(&rc->counter, 0);
+	env_atomic_set(&rc->freeze, 0);
+	env_atomic_set(&rc->callback, 0);
+	rc->cb = NULL;
+}
+
 void ocf_refcnt_dec(struct ocf_refcnt *rc)
 {
 	int val = env_atomic_dec_return(&rc->counter);

src/utils/utils_refcnt.h

@@ -19,6 +19,9 @@ struct ocf_refcnt
 	void *priv;
 };
 
+/* Initialize reference counter */
+void ocf_refcnt_init(struct ocf_refcnt *rc);
+
 /* Try to increment counter. Returns true if successfull, false if freezed */
 bool ocf_refcnt_inc(struct ocf_refcnt  *rc);