[libvirt] [PATCHv6 2/7] qemu: monitor: Add argument for specifying backing name for block commit

[Peter Krempa]

To allow changing the name that is recorded in the overlay of the TOP
image used in a block commit operation, we need to specify the backing
name to qemu. This is done via the "backing-file" attribute to the
block-commit command.
---
 src/qemu/qemu_driver.c       |  1 +
 src/qemu/qemu_monitor.c      | 10 ++++++----
 src/qemu/qemu_monitor.h      |  1 +
 src/qemu/qemu_monitor_json.c |  2 ++
 src/qemu/qemu_monitor_json.h |  1 +
 tests/qemumonitorjsontest.c  |  2 +-
 6 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 224df54..9f9fdea 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -15642,6 +15642,7 @@ qemuDomainBlockCommit(virDomainPtr dom,
     ret = qemuMonitorBlockCommit(priv->mon, device,
                                  top && !topIndex ? top : topSource->path,
                                  base && !baseIndex ? base : baseSource->path,
+                                 NULL,
                                  bandwidth);
     qemuDomainObjExitMonitor(driver, vm);

diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 2d584fc..3bc06e5 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -3234,13 +3234,14 @@ qemuMonitorTransaction(qemuMonitorPtr mon, virJSONValuePtr actions)
 int
 qemuMonitorBlockCommit(qemuMonitorPtr mon, const char *device,
                        const char *top, const char *base,
+                       const char *backingName,
                        unsigned long bandwidth)
 {
     int ret = -1;
     unsigned long long speed;

-    VIR_DEBUG("mon=%p, device=%s, top=%s, base=%s, bandwidth=%ld",
-              mon, device, top, base, bandwidth);
+    VIR_DEBUG("mon=%p, device=%s, top=%s, base=%s, backingName=%s, bandwidth=%lu",
+              mon, device, top, base, NULLSTR(backingName), bandwidth);

     /* Convert bandwidth MiB to bytes - unfortunately the JSON QMP protocol is
      * limited to LLONG_MAX also for unsigned values */
@@ -3254,7 +3255,8 @@ qemuMonitorBlockCommit(qemuMonitorPtr mon, const char *device,
     speed <<= 20;

     if (mon->json)
-        ret = qemuMonitorJSONBlockCommit(mon, device, top, base, speed);
+        ret = qemuMonitorJSONBlockCommit(mon, device, top, base,
+                                         backingName, speed);
     else
         virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
                        _("block-commit requires JSON monitor"));
@@ -3269,7 +3271,7 @@ qemuMonitorSupportsActiveCommit(qemuMonitorPtr mon)
     if (!mon->json)
         return false;

-    return qemuMonitorJSONBlockCommit(mon, "bogus", NULL, NULL, 0) == -2;
+    return qemuMonitorJSONBlockCommit(mon, "bogus", NULL, NULL, NULL, 0) == -2;
 }


diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 63e78d8..4652ea5 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -662,6 +662,7 @@ int qemuMonitorBlockCommit(qemuMonitorPtr mon,
                            const char *device,
                            const char *top,
                            const char *base,
+                           const char *backingName,
                            unsigned long bandwidth)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
     ATTRIBUTE_NONNULL(4);
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 75b33e8..719be66 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -3465,6 +3465,7 @@ qemuMonitorJSONTransaction(qemuMonitorPtr mon, virJSONValuePtr actions)
 int
 qemuMonitorJSONBlockCommit(qemuMonitorPtr mon, const char *device,
                            const char *top, const char *base,
+                           const char *backingName,
                            unsigned long long speed)
 {
     int ret = -1;
@@ -3476,6 +3477,7 @@ qemuMonitorJSONBlockCommit(qemuMonitorPtr mon, const char *device,
                                      "U:speed", speed,
                                      "S:top", top,
                                      "S:base", base,
+                                     "S:backing-file", backingName,
                                      NULL);
     if (!cmd)
         return -1;
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index 89e668c..652a4b6 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -261,6 +261,7 @@ int qemuMonitorJSONBlockCommit(qemuMonitorPtr mon,
                                const char *device,
                                const char *top,
                                const char *base,
+                               const char *backingName,
                                unsigned long long bandwidth)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);

diff --git a/tests/qemumonitorjsontest.c b/tests/qemumonitorjsontest.c
index d136576..6debe13 100644
--- a/tests/qemumonitorjsontest.c
+++ b/tests/qemumonitorjsontest.c
@@ -1164,7 +1164,7 @@ GEN_TEST_FUNC(qemuMonitorJSONAddDevice, "some_dummy_devicestr")
 GEN_TEST_FUNC(qemuMonitorJSONSetDrivePassphrase, "vda", "secret_passhprase")
 GEN_TEST_FUNC(qemuMonitorJSONDriveMirror, "vdb", "/foo/bar", NULL, 1024,
               VIR_DOMAIN_BLOCK_REBASE_SHALLOW | VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT)
-GEN_TEST_FUNC(qemuMonitorJSONBlockCommit, "vdb", "/foo/bar1", "/foo/bar2", 1024)
+GEN_TEST_FUNC(qemuMonitorJSONBlockCommit, "vdb", "/foo/bar1", "/foo/bar2", NULL, 1024)
 GEN_TEST_FUNC(qemuMonitorJSONDrivePivot, "vdb", NULL, NULL)
 GEN_TEST_FUNC(qemuMonitorJSONScreendump, "/foo/bar")
 GEN_TEST_FUNC(qemuMonitorJSONOpenGraphics, "spice", "spicefd", false)
-- 
1.9.3