bdrv_unref_child() does the following things:
- Updates the child->bs->inherits_from pointer.
- Calls bdrv_detach_child() to remove the BdrvChild from bs->children.
- Calls bdrv_unref() to unref the child BlockDriverState.
When bdrv_unref_child() was introduced in commit 33a604075c it was not
used in bdrv_close() because the drivers that had additional children
(like quorum or blkverify) had already called bdrv_unref() on their
children during their own close functions.
This was changed later (in 0bd6e91a7e for quorum, in 3e586be0b2 for
blkverify) so there's no reason not to use bdrv_unref_child() in
bdrv_close() anymore.
After this there's also no need to remove bs->backing and bs->file
separately from the rest of the children, so bdrv_close() can be
simplified.
Now bdrv_close() unrefs all children (before this patch it was only
bs->file and bs->backing). As a result, none of the callers of
brvd_attach_child() should remove their reference to child_bs (because
this function effectively steals that reference). This patch updates a
couple of tests that where doing their own bdrv_unref().
Signed-off-by: Alberto Garcia <be...@igalia.com>
---
block.c | 16 +++-------------
tests/test-bdrv-drain.c | 6 ------
tests/test-bdrv-graph-mod.c | 1 -
3 files changed, 3 insertions(+), 20 deletions(-)
diff --git a/block.c b/block.c
index 5c2c6aa761..3c3bd0f8d2 100644
--- a/block.c
+++ b/block.c
@@ -3842,22 +3842,12 @@ static void bdrv_close(BlockDriverState *bs)
bs->drv = NULL;
}
- bdrv_set_backing_hd(bs, NULL, &error_abort);
-
- if (bs->file != NULL) {
- bdrv_unref_child(bs, bs->file);
- bs->file = NULL;
- }
-
QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
- /* TODO Remove bdrv_unref() from drivers' close function and use
- * bdrv_unref_child() here */
- if (child->bs->inherits_from == bs) {
- child->bs->inherits_from = NULL;
- }
- bdrv_detach_child(child);
+ bdrv_unref_child(bs, child);
}
+ bs->backing = NULL;
+ bs->file = NULL;
g_free(bs->opaque);
bs->opaque = NULL;
atomic_set(&bs->copy_on_read, 0);
diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index eda90750eb..5534c2adf9 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -1436,12 +1436,6 @@ static void test_detach_indirect(bool by_parent_cb)
bdrv_unref(parent_b);
blk_unref(blk);
- /* XXX Once bdrv_close() unref's children instead of just detaching them,
- * this won't be necessary any more. */
- bdrv_unref(a);
- bdrv_unref(a);
- bdrv_unref(c);
-
g_assert_cmpint(a->refcnt, ==, 1);
g_assert_cmpint(b->refcnt, ==, 1);
g_assert_cmpint(c->refcnt, ==, 1);
diff --git a/tests/test-bdrv-graph-mod.c b/tests/test-bdrv-graph-mod.c
index 283dc84869..747c0bf8fc 100644
--- a/tests/test-bdrv-graph-mod.c
+++ b/tests/test-bdrv-graph-mod.c
@@ -116,7 +116,6 @@ static void test_update_perm_tree(void)
g_assert_nonnull(local_err);
error_free(local_err);
- bdrv_unref(bs);
blk_unref(root);
}
--
2.11.0
