blockcommit: fix regression with explicit top argument

Commit f586965 accidentally changed the semantics of the
virDomainBlockCommit command; where it previously looked for
an explicit top argument from the top of the chain, it now
starts from the backing file of the top.  Of course, until
we allow active commits, the only difference it makes is in
the quality of the error message, but with code for active
commit coming soon, we need to support an explicit mention
of the active layer.

* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Start looking
from top of chain.

Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index e147d282c59dc0b7a5d517326405c5965add9469..b5f7b3ce42c955db88cf407a556b19e0857d2bdd 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -15529,8 +15529,7 @@ qemuDomainBlockCommit(virDomainPtr dom,
     if (!top)
         topSource = disk->src;
     else if (virStorageFileParseChainIndex(disk->dst, top, &topIndex) < 0 ||
-             !(topSource = virStorageFileChainLookup(disk->src,
-                                                     disk->src->backingStore,
+             !(topSource = virStorageFileChainLookup(disk->src, NULL,
                                                      top, topIndex,
                                                      &top_parent)))
         goto endjob;