qemu: checkpoint: Track and relabel images for bitmap merging

Allow qemu access to modify backing files in case when we want to delete
a checkpoint.

This patch adds tracking of which images need to be relabelled when
calculating the transaction, the code to relabel them and rollback.

To verify that stuff works we also output the list of images to relabel
into the test case output files in qemublocktest.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/src/qemu/qemu_checkpoint.c b/src/qemu/qemu_checkpoint.c
index 55061bbf7653185e847e9c364cace6eae4b380d7..59b7f63fdc2582354d264620a1cdaf42a2c6d1e7 100644 (file)
--- a/src/qemu/qemu_checkpoint.c
+++ b/src/qemu/qemu_checkpoint.c
@@ -155,7 +155,8 @@ qemuCheckpointDiscardDiskBitmaps(virStorageSourcePtr src,
                                  const char *delbitmap,
                                  const char *parentbitmap,
                                  virJSONValuePtr actions,
-                                 const char *diskdst)
+                                 const char *diskdst,
+                                 GSList **reopenimages)
 {
     virStorageSourcePtr n = src;
 
@@ -235,6 +236,9 @@ qemuCheckpointDiscardDiskBitmaps(virStorageSourcePtr src,
                                                srcbitmap->name) < 0)
             return -1;
 
+        if (n != src)
+            *reopenimages = g_slist_prepend(*reopenimages, n);
+
         n = n->backingStore;
     }
 
@@ -250,9 +254,12 @@ qemuCheckpointDiscardBitmaps(virDomainObjPtr vm,
     qemuDomainObjPrivatePtr priv = vm->privateData;
     virQEMUDriverPtr driver = priv->driver;
     g_autoptr(virHashTable) blockNamedNodeData = NULL;
-    int rc;
+    int rc = -1;
     g_autoptr(virJSONValue) actions = NULL;
     size_t i;
+    g_autoptr(GSList) reopenimages = NULL;
+    g_autoptr(GSList) relabelimages = NULL;
+    GSList *next;
 
     if (!(actions = virJSONValueNewArray()))
         return -1;
@@ -284,16 +291,34 @@ qemuCheckpointDiscardBitmaps(virDomainObjPtr vm,
 
         if (qemuCheckpointDiscardDiskBitmaps(domdisk->src, blockNamedNodeData,
                                              chkdisk->bitmap, parentbitmap,
-                                             actions, domdisk->dst) < 0)
+                                             actions, domdisk->dst,
+                                             &reopenimages) < 0)
             return -1;
     }
 
+    /* label any non-top images for read-write access */
+    for (next = reopenimages; next; next = next->next) {
+        virStorageSourcePtr src = next->data;
+
+        if (qemuDomainStorageSourceAccessAllow(driver, vm, src, false, false) < 0)
+            goto relabel;
+
+        relabelimages = g_slist_prepend(relabelimages, src);
+    }
+
     qemuDomainObjEnterMonitor(driver, vm);
     rc = qemuMonitorTransaction(priv->mon, &actions);
-    if (qemuDomainObjExitMonitor(driver, vm) < 0 || rc < 0)
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
         return -1;
 
-    return 0;
+ relabel:
+    for (next = relabelimages; next; next = next->next) {
+        virStorageSourcePtr src = next->data;
+
+        ignore_value(qemuDomainStorageSourceAccessAllow(driver, vm, src, true, false));
+    }
+
+    return rc;
 }
 
 

diff --git a/src/qemu/qemu_checkpoint.h b/src/qemu/qemu_checkpoint.h
index 976b1eed0f6d22f58836819a66166eed0344a2d5..cf1e9e46cb25093f5ab935921ef2b3f0c6e2751a 100644 (file)
--- a/src/qemu/qemu_checkpoint.h
+++ b/src/qemu/qemu_checkpoint.h
@@ -78,4 +78,5 @@ qemuCheckpointDiscardDiskBitmaps(virStorageSourcePtr src,
                                  const char *delbitmap,
                                  const char *parentbitmap,
                                  virJSONValuePtr actions,
-                                 const char *diskdst);
+                                 const char *diskdst,
+                                 GSList **reopenimages);

diff --git a/tests/qemublocktest.c b/tests/qemublocktest.c
index 8f290452062ff81c7959506eed397a61e7c95f91..f518b0e025353780ad4a34a2b2aa4fb133fde7a7 100644 (file)
--- a/tests/qemublocktest.c
+++ b/tests/qemublocktest.c
@@ -721,6 +721,9 @@ testQemuCheckpointDeleteMerge(const void *opaque)
     g_autoptr(virJSONValue) actions = NULL;
     g_autoptr(virJSONValue) nodedatajson = NULL;
     g_autoptr(virHashTable) nodedata = NULL;
+    g_autoptr(GSList) reopenimages = NULL;
+    g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER;
+    GSList *tmp;
 
     expectpath = g_strdup_printf("%s/%s%s-out.json", abs_srcdir,
                                  checkpointDeletePrefix, data->name);
@@ -742,14 +745,26 @@ testQemuCheckpointDeleteMerge(const void *opaque)
                                          data->deletebitmap,
                                          data->parentbitmap,
                                          actions,
-                                         "testdisk") < 0) {
+                                         "testdisk",
+                                         &reopenimages) < 0) {
         VIR_TEST_VERBOSE("failed to generate checkpoint delete transaction\n");
         return -1;
     }
 
-    if (!(actual = virJSONValueToString(actions, true)))
+    if (virJSONValueToBuffer(actions, &buf, true) < 0)
         return -1;
 
+    if (reopenimages) {
+        virBufferAddLit(&buf, "reopen nodes:\n");
+
+        for (tmp = reopenimages; tmp; tmp = tmp->next) {
+            virStorageSourcePtr src = tmp->data;
+            virBufferAsprintf(&buf, "%s\n", src->nodeformat);
+        }
+    }
+
+    actual = virBufferContentAndReset(&buf);
+
     return virTestCompareToFile(actual, expectpath);
 }
 

diff --git a/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate1-out.json b/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate1-out.json
index 29fefeea6301756cbcd05437a5944e9490229225..c9bda3a17a9e40e222c523cc81260fa94c402b7e 100644 (file)
--- a/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate1-out.json
+++ b/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate1-out.json
@@ -20,3 +20,5 @@
     }
   }
 ]
+reopen nodes:
+libvirt-3-format

diff --git a/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate2-out.json b/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate2-out.json
index 4da21a9df71230df76d7b6a0e8e6963f7a310d1f..8a0e3f2cff8d9bbc050f026698c2671c26d227ad 100644 (file)
--- a/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate2-out.json
+++ b/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate2-out.json
@@ -57,3 +57,6 @@
     }
   }
 ]
+reopen nodes:
+libvirt-3-format
+libvirt-2-format

diff --git a/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate3-out.json b/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate3-out.json
index dc87dd60b87335a19cf6a9f1be590877f75da4be..211bc40bafbd2ebf9325eaf48198f0142278b469 100644 (file)
--- a/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate3-out.json
+++ b/tests/qemublocktestdata/checkpointdelete/snapshots-intermediate3-out.json
@@ -57,3 +57,5 @@
     }
   }
 ]
+reopen nodes:
+libvirt-2-format

diff --git a/tests/qemublocktestdata/checkpointdelete/snapshots-noparent-out.json b/tests/qemublocktestdata/checkpointdelete/snapshots-noparent-out.json
index 45a84b47c24ca7cde95f72acb0ecdaf8008cfa8e..f750f44da2029eac82d3deb1936b1ab2b0fbb84f 100644 (file)
--- a/tests/qemublocktestdata/checkpointdelete/snapshots-noparent-out.json
+++ b/tests/qemublocktestdata/checkpointdelete/snapshots-noparent-out.json
@@ -21,3 +21,7 @@
     }
   }
 ]
+reopen nodes:
+libvirt-5-format
+libvirt-4-format
+libvirt-3-format

diff --git a/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate1-out.json b/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate1-out.json
index e979691e6fc1661c34babbbd4d37660ee3d68ea0..d7e6d1863742f2d70582c9bdd0ef6fd96f240338 100644 (file)
--- a/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate1-out.json
+++ b/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate1-out.json
@@ -27,3 +27,5 @@
     }
   }
 ]
+reopen nodes:
+libvirt-3-format

diff --git a/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate2-out.json b/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate2-out.json
index e82098918aeece855289b7f47901ac75ab18517d..cfbff010c2c6ddfa051a4e72fe8147b16fd52d3d 100644 (file)
--- a/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate2-out.json
+++ b/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate2-out.json
@@ -30,3 +30,5 @@
     }
   }
 ]
+reopen nodes:
+libvirt-2-format

diff --git a/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate3-out.json b/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate3-out.json
index dc87dd60b87335a19cf6a9f1be590877f75da4be..211bc40bafbd2ebf9325eaf48198f0142278b469 100644 (file)
--- a/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate3-out.json
+++ b/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-intermediate3-out.json
@@ -57,3 +57,5 @@
     }
   }
 ]
+reopen nodes:
+libvirt-2-format

diff --git a/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-noparent-out.json b/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-noparent-out.json
index 45a84b47c24ca7cde95f72acb0ecdaf8008cfa8e..f750f44da2029eac82d3deb1936b1ab2b0fbb84f 100644 (file)
--- a/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-noparent-out.json
+++ b/tests/qemublocktestdata/checkpointdelete/snapshots-synthetic-checkpoint-noparent-out.json
@@ -21,3 +21,7 @@
     }
   }
 ]
+reopen nodes:
+libvirt-5-format
+libvirt-4-format
+libvirt-3-format