[libvirt] [PATCH v3 13/18] virSecuritySELinuxTransactionRun: Implement rollback

[Michal Privoznik]

When iterating over list of paths/disk sources to relabel it may
happen that the process fails at some point. In that case, for
the sake of keeping seclabel refcount (stored in XATTRs) in sync
with reality we have to perform rollback. However, if that fails
too the only thing we can do is warn user.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange at redhat.com>
---
 src/security/security_selinux.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/security/security_selinux.c b/src/security/security_selinux.c
index f52c88259d..4b68eb2717 100644
--- a/src/security/security_selinux.c
+++ b/src/security/security_selinux.c
@@ -276,7 +276,6 @@ virSecuritySELinuxTransactionRun(pid_t pid ATTRIBUTE_UNUSED,
     for (i = 0; i < list->nItems; i++) {
         virSecuritySELinuxContextItemPtr item = list->items[i];
 
-        /* TODO Implement rollback */
         if (!item->restore) {
             rv = virSecuritySELinuxSetFileconHelper(list->manager,
                                                     item->path,
@@ -293,6 +292,18 @@ virSecuritySELinuxTransactionRun(pid_t pid ATTRIBUTE_UNUSED,
             break;
     }
 
+    for (; rv < 0 && i > 0; i--) {
+        virSecuritySELinuxContextItemPtr item = list->items[i - 1];
+
+        if (!item->restore) {
+            virSecuritySELinuxRestoreFileLabel(list->manager,
+                                               item->path,
+                                               list->lock);
+        } else {
+            VIR_WARN("Ignoring failed restore attempt on %s", item->path);
+        }
+    }
+
     if (list->lock)
         virSecurityManagerMetadataUnlock(list->manager, &state);
 
-- 
2.19.2