block: Use bdrv_filter_(bs|child) where obvious

Places that use patterns like

    if (bs->drv->is_filter && bs->file) {
        ... something about bs->file->bs ...
    }

should be

    BlockDriverState *filtered = bdrv_filter_bs(bs);
    if (filtered) {
        ... something about @filtered ...
    }

instead.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 20 insertions, 11 deletions

diff --git a/block.c b/block.c
index c09a766f54..887c125400 100644
--- a/block.c
+++ b/block.c
@@ -712,11 +712,12 @@ int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp)
 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
 {
     BlockDriver *drv = bs->drv;
+    BlockDriverState *filtered = bdrv_filter_bs(bs);
 
     if (drv && drv->bdrv_probe_blocksizes) {
         return drv->bdrv_probe_blocksizes(bs, bsz);
-    } else if (drv && drv->is_filter && bs->file) {
-        return bdrv_probe_blocksizes(bs->file->bs, bsz);
+    } else if (filtered) {
+        return bdrv_probe_blocksizes(filtered, bsz);
     }
 
     return -ENOTSUP;
@@ -731,11 +732,12 @@ int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
 {
     BlockDriver *drv = bs->drv;
+    BlockDriverState *filtered = bdrv_filter_bs(bs);
 
     if (drv && drv->bdrv_probe_geometry) {
         return drv->bdrv_probe_geometry(bs, geo);
-    } else if (drv && drv->is_filter && bs->file) {
-        return bdrv_probe_geometry(bs->file->bs, geo);
+    } else if (filtered) {
+        return bdrv_probe_geometry(filtered, geo);
     }
 
     return -ENOTSUP;
@@ -5442,6 +5444,8 @@ int bdrv_has_zero_init_1(BlockDriverState *bs)
 
 int bdrv_has_zero_init(BlockDriverState *bs)
 {
+    BlockDriverState *filtered;
+
     if (!bs->drv) {
         return 0;
     }
@@ -5454,8 +5458,10 @@ int bdrv_has_zero_init(BlockDriverState *bs)
     if (bs->drv->bdrv_has_zero_init) {
         return bs->drv->bdrv_has_zero_init(bs);
     }
-    if (bs->file && bs->drv->is_filter) {
-        return bdrv_has_zero_init(bs->file->bs);
+
+    filtered = bdrv_filter_bs(bs);
+    if (filtered) {
+        return bdrv_has_zero_init(filtered);
     }
 
     /* safe default */
@@ -5485,8 +5491,9 @@ int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
         return -ENOMEDIUM;
     }
     if (!drv->bdrv_get_info) {
-        if (bs->file && drv->is_filter) {
-            return bdrv_get_info(bs->file->bs, bdi);
+        BlockDriverState *filtered = bdrv_filter_bs(bs);
+        if (filtered) {
+            return bdrv_get_info(filtered, bdi);
         }
         return -ENOTSUP;
     }
@@ -6571,6 +6578,8 @@ int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
 bool bdrv_recurse_can_replace(BlockDriverState *bs,
                               BlockDriverState *to_replace)
 {
+    BlockDriverState *filtered;
+
     if (!bs || !bs->drv) {
         return false;
     }
@@ -6585,9 +6594,9 @@ bool bdrv_recurse_can_replace(BlockDriverState *bs,
     }
 
     /* For filters without an own implementation, we can recurse on our own */
-    if (bs->drv->is_filter) {
-        BdrvChild *child = bs->file ?: bs->backing;
-        return bdrv_recurse_can_replace(child->bs, to_replace);
+    filtered = bdrv_filter_bs(bs);
+    if (filtered) {
+        return bdrv_recurse_can_replace(filtered, to_replace);
     }
 
     /* Safe default */