block: add default implementations for bdrv_co_get_block_status()

bdrv_co_get_block_status_from_file() and
bdrv_co_get_block_status_from_backing() set *file to bs->file and
bs->backing respectively, so that bdrv_co_get_block_status() can recurse
to them. Future block drivers won't have to duplicate code to implement
this.

Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/block/io.c b/block/io.c
index 2600381..4378ae4 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1714,6 +1714,32 @@ typedef struct BdrvCoGetBlockStatusData {
     bool done;
 } BdrvCoGetBlockStatusData;
 
+int64_t coroutine_fn bdrv_co_get_block_status_from_file(BlockDriverState *bs,
+                                                        int64_t sector_num,
+                                                        int nb_sectors,
+                                                        int *pnum,
+                                                        BlockDriverState **file)
+{
+    assert(bs->file && bs->file->bs);
+    *pnum = nb_sectors;
+    *file = bs->file->bs;
+    return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
+           (sector_num << BDRV_SECTOR_BITS);
+}
+
+int64_t coroutine_fn bdrv_co_get_block_status_from_backing(BlockDriverState *bs,
+                                                           int64_t sector_num,
+                                                           int nb_sectors,
+                                                           int *pnum,
+                                                           BlockDriverState **file)
+{
+    assert(bs->backing && bs->backing->bs);
+    *pnum = nb_sectors;
+    *file = bs->backing->bs;
+    return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
+           (sector_num << BDRV_SECTOR_BITS);
+}
+
 /*
  * Returns the allocation status of the specified sectors.
  * Drivers not implementing the functionality are assumed to not support