@@ -306,6 +306,7 @@ BlockDriverState *bdrv_new(const char *device_name)
bdrv_iostatus_disable(bs);
notifier_list_init(&bs->close_notifiers);
notifier_with_return_list_init(&bs->before_write_notifiers);
+ bs->refcnt = 1;
return bs;
}
@@ -1518,6 +1519,9 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
/* dirty bitmap */
bs_dest->dirty_bitmap = bs_src->dirty_bitmap;
+ /* reference count */
+ bs_dest->refcnt = bs_src->refcnt;
+
/* job */
bs_dest->in_use = bs_src->in_use;
bs_dest->job = bs_src->job;
@@ -4392,6 +4396,23 @@ int64_t bdrv_get_dirty_count(BlockDriverState *bs)
}
}
+/* Get a reference to bs */
+void bdrv_ref(BlockDriverState *bs)
+{
+ bs->refcnt++;
+}
+
+/* Release a previously grabbed reference to bs.
+ * If after releasing, reference count is zero, the BlockDriverState is
+ * deleted. */
+void bdrv_unref(BlockDriverState *bs)
+{
+ assert(bs->refcnt > 0);
+ if (--bs->refcnt == 0) {
+ bdrv_delete(bs);
+ }
+}
+
void bdrv_set_in_use(BlockDriverState *bs, int in_use)
{
assert(bs->in_use != in_use);
@@ -356,6 +356,8 @@ int64_t bdrv_get_dirty_count(BlockDriverState *bs);
void bdrv_enable_copy_on_read(BlockDriverState *bs);
void bdrv_disable_copy_on_read(BlockDriverState *bs);
+void bdrv_ref(BlockDriverState *bs);
+void bdrv_unref(BlockDriverState *bs);
void bdrv_set_in_use(BlockDriverState *bs, int in_use);
int bdrv_in_use(BlockDriverState *bs);
@@ -294,6 +294,7 @@ struct BlockDriverState {
BlockDeviceIoStatus iostatus;
char device_name[32];
HBitmap *dirty_bitmap;
+ int refcnt;
int in_use; /* users other than guest access, eg. block migration */
QTAILQ_ENTRY(BlockDriverState) list;
Introduce bdrv_ref/bdrv_unref to manage the lifecycle of BlockDriverState. They are unused for now but will used to replace bdrv_delete() later. Signed-off-by: Fam Zheng <famz@redhat.com> --- block.c | 21 +++++++++++++++++++++ include/block/block.h | 2 ++ include/block/block_int.h | 1 + 3 files changed, 24 insertions(+)