qemu: Revoke access to mirror on failed blockcopy

When preparing to do a blockcopy, the mirror image is modified so
that QEMU can access it. For instance, the mirror has seclabels
set, if it is a NVMe disk it is detached from the host and so on.
And usually, the restore is done upon successful finish of the
blockcopy operation. But, if something fails then we need to
explicitly revoke the access to the mirror image (and thus
reattach NVMe disk back to the host).

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1822538
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Pavel Mores <pmores@redhat.com>

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 31f199fdefd0372d866ddfa8a70d1b6111f54c5c..dfe0adaad81a0503be9e0ef59dcdd115fc1c43db 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -17950,6 +17950,7 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
     virDomainDiskDefPtr disk = NULL;
     int ret = -1;
     bool need_unlink = false;
+    bool need_revoke = false;
     g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
     const char *format = NULL;
     bool mirror_reuse = !!(flags & VIR_DOMAIN_BLOCK_COPY_REUSE_EXT);
@@ -18124,6 +18125,7 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
 
     if (qemuDomainStorageSourceChainAccessAllow(driver, vm, mirror) < 0)
         goto endjob;
+    need_revoke = true;
 
     if (blockdev) {
         if (mirror_reuse) {
@@ -18232,14 +18234,17 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
 
  endjob:
     if (ret < 0 &&
-        virDomainObjIsActive(vm) &&
-        (data || crdata)) {
-        qemuDomainObjEnterMonitor(driver, vm);
-        if (data)
-            qemuBlockStorageSourceChainDetach(priv->mon, data);
-        if (crdata)
-            qemuBlockStorageSourceAttachRollback(priv->mon, crdata->srcdata[0]);
-        ignore_value(qemuDomainObjExitMonitor(driver, vm));
+        virDomainObjIsActive(vm)) {
+        if (data || crdata) {
+            qemuDomainObjEnterMonitor(driver, vm);
+            if (data)
+                qemuBlockStorageSourceChainDetach(priv->mon, data);
+            if (crdata)
+                qemuBlockStorageSourceAttachRollback(priv->mon, crdata->srcdata[0]);
+            ignore_value(qemuDomainObjExitMonitor(driver, vm));
+        }
+        if (need_revoke)
+            qemuDomainStorageSourceChainAccessRevoke(driver, vm, mirror);
     }
     if (need_unlink && virStorageFileUnlink(mirror) < 0)
         VIR_WARN("%s", _("unable to remove just-created copy target"));