[libvirt] [PATCH 6/8] qemu: block: Create helper for creating data for legacy snapshots

[Peter Krempa]

With 'transaction' support we don't need to keep around the multipurpose
code which would create the snapshot if 'transaction' is not supported.

To simplify this add a new helper that just wraps the arguments for
'blockdev-snapshot-sync' operation in 'transaction' and use it instead
of qemuBlockSnapshotAddLegacy.

Additionally this allows to format the arguments prior to creating the
file for simpler cleanup.

Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
 src/qemu/qemu_block.c  | 37 +++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_block.h  |  6 ++++++
 src/qemu/qemu_driver.c | 18 +++---------------
 3 files changed, 46 insertions(+), 15 deletions(-)

diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index 0ebf2d2aff..db1579ca20 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -19,8 +19,10 @@
 #include <config.h>

 #include "qemu_block.h"
+#include "qemu_command.h"
 #include "qemu_domain.h"
 #include "qemu_alias.h"
+#include "qemu_monitor_json.h"

 #include "viralloc.h"
 #include "virstring.h"
@@ -1683,3 +1685,38 @@ qemuBlockStorageSourceDetachOneBlockdev(virQEMUDriverPtr driver,

     return ret;
 }
+
+
+int
+qemuBlockSnapshotAddLegacy(virJSONValuePtr actions,
+                           virDomainDiskDefPtr disk,
+                           virStorageSourcePtr newsrc,
+                           bool reuse)
+{
+    const char *format = virStorageFileFormatTypeToString(newsrc->format);
+    char *device = NULL;
+    char *source = NULL;
+    int ret = -1;
+
+    if (!(device = qemuAliasDiskDriveFromDisk(disk)))
+        goto cleanup;
+
+    if (qemuGetDriveSourceString(newsrc, NULL, &source) < 0)
+        goto cleanup;
+
+    if (qemuMonitorJSONTransactionAdd(actions, "blockdev-snapshot-sync",
+                                      "s:device", device,
+                                      "s:snapshot-file", source,
+                                      "s:format", format,
+                                      "S:mode", reuse ? "existing" : NULL,
+                                       NULL) < 0)
+        goto cleanup;
+
+    ret = 0;
+
+ cleanup:
+    VIR_FREE(device);
+    VIR_FREE(source);
+
+    return ret;
+}
diff --git a/src/qemu/qemu_block.h b/src/qemu/qemu_block.h
index 418b5064b5..fd8984e60b 100644
--- a/src/qemu/qemu_block.h
+++ b/src/qemu/qemu_block.h
@@ -117,4 +117,10 @@ qemuBlockStorageSourceDetachOneBlockdev(virQEMUDriverPtr driver,
                                         qemuDomainAsyncJob asyncJob,
                                         virStorageSourcePtr src);

+int
+qemuBlockSnapshotAddLegacy(virJSONValuePtr actions,
+                           virDomainDiskDefPtr disk,
+                           virStorageSourcePtr newsrc,
+                           bool reuse);
+
 #endif /* __QEMU_BLOCK_H__ */
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index ea06e23ff1..2d8af5daaa 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -14932,23 +14932,16 @@ qemuDomainSnapshotCreateSingleDiskActive(virQEMUDriverPtr driver,
                                          virJSONValuePtr actions,
                                          bool reuse)
 {
-    qemuDomainObjPrivatePtr priv = vm->privateData;
-    char *device = NULL;
-    char *source = NULL;
-    const char *formatStr = NULL;
     int ret = -1;

-    if (!(device = qemuAliasDiskDriveFromDisk(dd->disk)))
-        goto cleanup;
-
-    if (qemuGetDriveSourceString(dd->src, NULL, &source) < 0)
+    if (qemuBlockSnapshotAddLegacy(actions, dd->disk, dd->src, reuse) < 0)
         goto cleanup;

     /* pre-create the image file so that we can label it before handing it to qemu */
     if (!reuse && dd->src->type != VIR_STORAGE_TYPE_BLOCK) {
         if (virStorageFileCreate(dd->src) < 0) {
             virReportSystemError(errno, _("failed to create image file '%s'"),
-                                 source);
+                                 NULLSTR(dd->src->path));
             goto cleanup;
         }
         dd->created = true;
@@ -14962,14 +14955,9 @@ qemuDomainSnapshotCreateSingleDiskActive(virQEMUDriverPtr driver,

     dd->prepared = true;

-    formatStr = virStorageFileFormatTypeToString(dd->src->format);
-
-    ret = qemuMonitorDiskSnapshot(priv->mon, actions, device, source,
-                                  formatStr, reuse);
+    ret = 0;

  cleanup:
-    VIR_FREE(device);
-    VIR_FREE(source);
     return ret;
 }

-- 
2.16.2