[PATCH v2] qemuProcessStop: Reattach NVMe disks a domain is mirroring into

[Michal Privoznik]

In v5.10.0-rc1~42 (which was later fixed in v6.0.0-rc1~487) I am
removing XATTRs for a file that QEMU is mirroring a disk into but
it is killed meanwhile. Well, we can call
qemuSecurityRestoreImageLabel() which will not only remove XATTRs
but also use them to restore the original owner of the file.
Moreover, if the mirror destination is not a file but a NVMe
disk, then call qemuHostdevReAttachOneNVMeDisk() to reattach the
NVMe back to the host.

All of this would be done by blockjob code when the job finishes,
but in this case the job won't finish - QEMU is killed meanwhile.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1825785

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

v2 of:

https://www.redhat.com/archives/libvir-list/2020-May/msg00210.html

diff to v1:
- per Peter's review, instead of calling qemuDomainStorageSourceAccessRevoke()
  call only some functions it would call.

 src/qemu/qemu_process.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 8ea470f75f..65d51e58c9 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -7604,8 +7604,13 @@ void qemuProcessStop(virQEMUDriverPtr driver,
         for (i = 0; i < def->ndisks; i++) {
             virDomainDiskDefPtr disk = def->disks[i];
 
-            if (disk->mirror)
-                qemuBlockRemoveImageMetadata(driver, vm, disk->dst, disk->mirror);
+            if (disk->mirror) {
+                if (qemuSecurityRestoreImageLabel(driver, vm, disk->mirror, false) < 0)
+                    VIR_WARN("Unable to restore security label on %s", disk->dst);
+
+                if (virStorageSourceChainHasNVMe(disk->mirror))
+                    qemuHostdevReAttachOneNVMeDisk(driver, vm->def->name, disk->mirror);
+            }
 
             qemuBlockRemoveImageMetadata(driver, vm, disk->dst, disk->src);
         }
-- 
2.26.2