[Qemu-block] [PATCH v6 1/9] block: Always set *file in get_block_status

[Max Reitz]

*file should always be set (to NULL, if nothing else) instead of leaving
it dangling sometimes. This should also be documented so callers can
rely on this behavior.

Signed-off-by: Max Reitz <address@hidden>
---
 block/io.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/block/io.c b/block/io.c
index 4f005623f7..ff693d7f73 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1709,7 +1709,8 @@ typedef struct BdrvCoGetBlockStatusData {
  * beyond the end of the disk image it will be clamped.
  *
  * If returned value is positive and BDRV_BLOCK_OFFSET_VALID bit is set, 'file'
- * points to the BDS which the sector range is allocated in.
+ * points to the BDS which the sector range is allocated in. If the block 
driver
+ * does not set 'file', it will be set to NULL.
  */
 static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
                                                      int64_t sector_num,
@@ -1720,6 +1721,8 @@ static int64_t coroutine_fn 
bdrv_co_get_block_status(BlockDriverState *bs,
     int64_t n;
     int64_t ret, ret2;
 
+    *file = NULL;
+
     total_sectors = bdrv_nb_sectors(bs);
     if (total_sectors < 0) {
         return total_sectors;
@@ -1744,7 +1747,6 @@ static int64_t coroutine_fn 
bdrv_co_get_block_status(BlockDriverState *bs,
         return ret;
     }
 
-    *file = NULL;
     bdrv_inc_in_flight(bs);
     ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum,
                                             file);
-- 
2.11.0