[libvirt] [PATCH v2 2/2] qemuProcessStop: Remove image metadata for running mirror jobs

[Michal Privoznik]

If user starts a blockcommit without --pivot or a blockcopy also
without --pivot then we modify access for qemu on both images and
leave it like that until pivot is executed. So far so good.
Problem is, if user instead of issuing pivot calls destroy on the
domain or if qemu dies whilst executing the block job. In this
case we don't ever clear the access we granted at the beginning.
To fix this, we need to mimic what block job code does for
aborting a block job -> remove image metadata from disk->mirror
and disk->src chains.

https://bugzilla.redhat.com/show_bug.cgi?id=1741456#c19

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---

Diff to v2:
- updated commit message
- do more remove - for disk->src chain too
- put a comment about the importance of code placement

 src/qemu/qemu_process.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 209d07cfe8..b9dd433f54 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -7615,6 +7615,18 @@ void qemuProcessStop(virQEMUDriverPtr driver,
     for (i = 0; i < vm->def->niothreadids; i++)
         vm->def->iothreadids[i]->thread_id = 0;
 
+    /* Do this explicitly after vm->pid is reset so that security drivers don't
+     * try to enter the domain's namespace which is non-existent by now as qemu
+     * is no longer running. */
+    for (i = 0; i < def->ndisks; i++) {
+        virDomainDiskDefPtr disk = def->disks[i];
+
+        if (disk->mirror)
+            qemuBlockRemoveImageMetadata(driver, vm, disk->dst, disk->mirror);
+
+        qemuBlockRemoveImageMetadata(driver, vm, disk->dst, disk->src);
+    }
+
     /* clear all private data entries which are no longer needed */
     qemuDomainObjPrivateDataClear(priv);
 
-- 
2.23.0