block: inline bdrv_unallocated_blocks_are_zero()

The function has only one user: bdrv_co_block_status(). Inline it to
simplify reviewing of the following patches, which will finally drop
unallocated_blocks_are_zero field too.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-3-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

3 files changed, 8 insertions, 19 deletions

diff --git a/block.c b/block.c
index 144f52e..62e40db 100644
--- a/block.c
+++ b/block.c
@@ -5408,21 +5408,6 @@ int bdrv_has_zero_init(BlockDriverState *bs)
     return 0;
 }
 
-bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
-{
-    BlockDriverInfo bdi;
-
-    if (bs->backing) {
-        return false;
-    }
-
-    if (bdrv_get_info(bs, &bdi) == 0) {
-        return bdi.unallocated_blocks_are_zero;
-    }
-
-    return false;
-}
-
 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
 {
     if (!(bs->open_flags & BDRV_O_UNMAP)) {
diff --git a/block/io.c b/block/io.c
index df8f2a9..36d4d56 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2407,15 +2407,20 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs,
     if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
         ret |= BDRV_BLOCK_ALLOCATED;
     } else if (want_zero) {
-        if (bdrv_unallocated_blocks_are_zero(bs)) {
-            ret |= BDRV_BLOCK_ZERO;
-        } else if (bs->backing) {
+        if (bs->backing) {
             BlockDriverState *bs2 = bs->backing->bs;
             int64_t size2 = bdrv_getlength(bs2);
 
             if (size2 >= 0 && offset >= size2) {
                 ret |= BDRV_BLOCK_ZERO;
             }
+        } else {
+            BlockDriverInfo bdi;
+            int ret2 = bdrv_get_info(bs, &bdi);
+
+            if (ret2 == 0 && bdi.unallocated_blocks_are_zero) {
+                ret |= BDRV_BLOCK_ZERO;
+            }
         }
     }
 
diff --git a/include/block/block.h b/include/block/block.h
index a2414a5..e7934e0 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -489,7 +489,6 @@ int bdrv_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
 int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
 int bdrv_has_zero_init_1(BlockDriverState *bs);
 int bdrv_has_zero_init(BlockDriverState *bs);
-bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 int bdrv_block_status(BlockDriverState *bs, int64_t offset,
                       int64_t bytes, int64_t *pnum, int64_t *map,