diff options
| -rw-r--r-- | block.c | 21 | ||||
| -rw-r--r-- | include/block/block.h | 2 | ||||
| -rw-r--r-- | include/block/block_int.h | 1 |
3 files changed, 24 insertions, 0 deletions
diff --git a/block.c b/block.c index 0292d1ddc9..a2b60031a2 100644 --- a/block.c +++ b/block.c @@ -332,6 +332,7 @@ BlockDriverState *bdrv_new(const char *device_name) notifier_with_return_list_init(&bs->before_write_notifiers); qemu_co_queue_init(&bs->throttled_reqs[0]); qemu_co_queue_init(&bs->throttled_reqs[1]); + bs->refcnt = 1; return bs; } @@ -1566,6 +1567,9 @@ 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; @@ -4297,6 +4301,23 @@ 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); diff --git a/include/block/block.h b/include/block/block.h index 6207ff2cec..f24e1fffe2 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -355,6 +355,8 @@ 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); diff --git a/include/block/block_int.h b/include/block/block_int.h index c3c9c61fa5..b9212b8331 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -277,6 +277,7 @@ 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; |