From 60244b56afb3438080b55ac838766af3a0037e03 Mon Sep 17 00:00:00 2001
From: Peter Krempa <pkrempa@redhat.com>
Date: Mon, 28 Apr 2014 15:39:19 +0200
Subject: [PATCH] qemu: Add support for networked disks for block commit

Now that we are able to select images from the backing chain via indexed
access we should also convert possible network sources to
qemu-compatible strings before passing them to qemu.
---
 src/qemu/qemu_driver.c | 38 ++++++++++++++++++++++++++++++++++----
 1 file changed, 34 insertions(+), 4 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 23f3f089a8..fa5f9c34b8 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -15505,9 +15505,13 @@ qemuDomainBlockCommit(virDomainPtr dom,
     unsigned int baseIndex = 0;
     const char *top_parent = NULL;
     bool clean_access = false;
+    char *topPath = NULL;
+    char *basePath = NULL;
+    char *backingPath = NULL;
 
     /* XXX Add support for COMMIT_ACTIVE, COMMIT_DELETE */
-    virCheckFlags(VIR_DOMAIN_BLOCK_COMMIT_SHALLOW, -1);
+    virCheckFlags(VIR_DOMAIN_BLOCK_COMMIT_SHALLOW |
+                  VIR_DOMAIN_BLOCK_COMMIT_RELATIVE, -1);
 
     if (!(vm = qemuDomObjFromDomain(dom)))
         goto cleanup;
@@ -15617,6 +15621,31 @@ qemuDomainBlockCommit(virDomainPtr dom,
                                                VIR_DISK_CHAIN_READ_WRITE) < 0))
         goto endjob;
 
+    if (qemuGetDriveSourceString(topSource, NULL, &topPath) < 0)
+        goto endjob;
+
+    if (qemuGetDriveSourceString(baseSource, NULL, &basePath) < 0)
+        goto endjob;
+
+    if (flags & VIR_DOMAIN_BLOCK_COMMIT_RELATIVE &&
+        topSource != disk->src) {
+        if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_CHANGE_BACKING_FILE)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("this qemu doesn't support relative blockpull"));
+            goto endjob;
+        }
+
+        if (virStorageFileGetRelativeBackingPath(topSource, baseSource,
+                                                 &backingPath) < 0)
+            goto endjob;
+
+        if (!backingPath) {
+            virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+                           _("can't keep relative backing relationship"));
+            goto endjob;
+        }
+    }
+
     /* Start the commit operation.  Pass the user's original spelling,
      * if any, through to qemu, since qemu may behave differently
      * depending on whether the input was specified as relative or
@@ -15624,9 +15653,7 @@ qemuDomainBlockCommit(virDomainPtr dom,
      * thing if the user specified a relative name). */
     qemuDomainObjEnterMonitor(driver, vm);
     ret = qemuMonitorBlockCommit(priv->mon, device,
-                                 top && !topIndex ? top : topSource->path,
-                                 base && !baseIndex ? base : baseSource->path,
-                                 NULL,
+                                 topPath, basePath, backingPath,
                                  bandwidth);
     qemuDomainObjExitMonitor(driver, vm);
 
@@ -15644,6 +15671,9 @@ qemuDomainBlockCommit(virDomainPtr dom,
         vm = NULL;
 
  cleanup:
+    VIR_FREE(topPath);
+    VIR_FREE(basePath);
+    VIR_FREE(backingPath);
     VIR_FREE(device);
     if (vm)
         virObjectUnlock(vm);