[libvirt] [PATCH] Reject duplicate disk targets

[Martin Kletzander]

We never check for disks with duplicate targets connected to the same
controller/bus/etc.  That means we go ahead, create the same IDs for
them and pass them to qemu, which subsequently fails to start.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=968899
Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
---
 src/conf/domain_conf.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 3398d8b..01720e1 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -2629,6 +2629,45 @@ virDomainDeviceInfoIterate(virDomainDefPtr def,


 static int
+virDomainDefRejectDuplicateDiskTargets(virDomainDefPtr def)
+{
+    char *disk_id = NULL;
+    int ret = -1;
+    size_t i = 0;
+    virHashTablePtr targets = NULL;
+
+    if (!(targets = virHashCreate(def->ndisks, NULL)))
+        goto cleanup;
+
+    for (i = 0; i < def->ndisks; i++) {
+        virDomainDiskDefPtr disk = def->disks[i];
+
+        if (virAsprintf(&disk_id, "%d%s%d%d%d%d",
+                        disk->bus,
+                        NULLSTR(disk->dst),
+                        disk->info.addr.drive.controller,
+                        disk->info.addr.drive.bus,
+                        disk->info.addr.drive.target,
+                        disk->info.addr.drive.unit) < 0)
+            goto cleanup;
+
+        if (virHashAddEntry(targets, disk_id, NULL) < 0) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("Multiple disks with same address and target ('%s')"),
+                           def->disks[i]->dst);
+            VIR_FREE(disk_id);
+            goto cleanup;
+        }
+        VIR_FREE(disk_id);
+    }
+
+    ret = 0;
+ cleanup:
+    virHashFree(targets);
+    return ret;
+}
+
+static int
 virDomainDefRejectDuplicateControllers(virDomainDefPtr def)
 {
     int max_idx[VIR_DOMAIN_CONTROLLER_TYPE_LAST];
@@ -2762,7 +2801,8 @@ virDomainDefPostParseInternal(virDomainDefPtr def,
         }
     }

-    if (virDomainDefRejectDuplicateControllers(def) < 0)
+    if (virDomainDefRejectDuplicateControllers(def) < 0 ||
+        virDomainDefRejectDuplicateDiskTargets(def) < 0)
         return -1;
     return 0;
 }
-- 
1.8.3.2