7:39 a.m.
To break the chicken and egg problem loop between qemu and libvirt in
using new features introduce experimental support for blockdev-reopen
(or actually x-blockdev-reopen for the time being).
This patchset adds QEMU_CAPS_BLOCKDEV_REOPEN capability which is
currently not asserted until qemu stabilizes the blockdev-reopen
interface but implements all the handlers to use it.
This is a similar approach we used to add all of the bits required to
use -blockdev with qemu.
To show it's usefullnes two real problems are addressed using reopening:
- Checkpoint deletion in backing chain, where we need to reopen
the read-only backing images to allow modification of bitmaps.
Using this approach will prevent qemu from having to introduce yet
another ad-hoc interface to deal with the bitmaps.
(note that checkpoints are also experimental themselves since they
are part of the not-yet-finished incremental backup feature)
- Late open of backing files for virDomainBlockCopy
oVirt abuses a quirk in the old handling of block-copy when
drive-mirror is used as qemu opens the backing images of the
destination of the copy only once block-job-complete is called.
Without blockdev-reopen it's impossible to replicate the old semantics
as we need to install a backing file for the mirror copy and that
is possible only using blockdev-reopen.
(this change will stay disabled until blockdev-reopen is stabilized)
There are a few other problems which this will deal with mostly related
to bitmap handling which would also require ad-hoc qemu functionality
otherwise.
Since we have an existing interface we can show we are willing to use it
to prevent wasting more engieering on qemu's side on partial solutions.
This patchset applies on top of:
https://www.redhat.com/archives/libvir-list/2020-February/msg01062.html
It can be fetched from my repo:
git fetch https://gitlab.com/pipo.sk/libvirt.git reopen-impl
https://gitlab.com/pipo.sk/libvirt/-/commits/reopen-impl
Note the above branch contains also patches which enable the feature
and also enable incremental backup to facilitate simple testing
without the need to use the qemu namespace.
Successful use requires the following qemu patches:
https://lists.gnu.org/archive/html/qemu-block/2020-02/msg01423.html
https://lists.gnu.org/archive/html/qemu-block/2020-02/msg01467.html
A qemu repo containing the above patches and patch to enable the
detection done in my private brnch mentioned above can be fetched at:
git fetch https://gitlab.com/pipo.sk/qemu.git bitmap-reopen
https://gitlab.com/pipo.sk/qemu/-/commits/bitmap-reopen
Peter Krempa (8):
qemu: capabilities: Add QEMU_CAPS_BLOCKDEV_REOPEN
qemu: monitor: Add handler for blockdev-reopen
qemu: block: implement helpers for blockdev-reopen
qemuCheckpointDiscardBitmaps: Reopen images for bitmap modifications
qemuCheckpointDiscardBitmaps: Use correct field for checkpoint bitmap
name
qemuDomainBlockPivot: Move check prior to executing the pivot steps
qemuDomainBlockCopyCommon: Record updated flags to block job
qemu: blockcopy: Allow late opening of the backing chain of a shallow
copy
src/qemu/qemu_block.c | 121 +++++++++++++++++++++++++++++++++++
src/qemu/qemu_block.h | 14 ++++
src/qemu/qemu_capabilities.c | 1 +
src/qemu/qemu_capabilities.h | 1 +
src/qemu/qemu_checkpoint.c | 6 +-
src/qemu/qemu_driver.c | 67 ++++++++++++++++---
src/qemu/qemu_monitor.c | 13 ++++
src/qemu/qemu_monitor.h | 3 +
src/qemu/qemu_monitor_json.c | 21 ++++++
src/qemu/qemu_monitor_json.h | 4 ++
10 files changed, 241 insertions(+), 10 deletions(-)
--
2.24.1
7:39 a.m.
New subject: [PATCH 1/8] qemu: capabilities: Add QEMU_CAPS_BLOCKDEV_REOPEN
This capability will be asserted once qemu stabilizes 'blockdev-reopen'.
For now we just add the capability so that we can introduce some code
that will use the reopening call. This will show our willingness to
adopt use of reopen and help qemu developers stabilize it.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_capabilities.c | 1 +
src/qemu/qemu_capabilities.h | 1 +
2 files changed, 2 insertions(+)
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 5548ffad14..1cb8b697e0 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -564,6 +564,7 @@ VIR_ENUM_IMPL(virQEMUCaps,
/* 355 */
"query-named-block-nodes.flat",
+ "blockdev-reopen",
);
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index ffb4206723..f7e420a006 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -545,6 +545,7 @@ typedef enum { /* virQEMUCapsFlags grouping marker for syntax-check
*/
/* 355 */
QEMU_CAPS_QMP_QUERY_NAMED_BLOCK_NODES_FLAT, /* query-named-block-nodes supports the
'flat' option */
+ QEMU_CAPS_BLOCKDEV_REOPEN, /* 'blockdev-reopen' qmp command is supported */
QEMU_CAPS_LAST /* this must always be the last item */
} virQEMUCapsFlags;
--
2.24.1
7:39 a.m.
New subject: [PATCH 2/8] qemu: monitor: Add handler for blockdev-reopen
Introduce the monitor code for using blockdev-reopen. For now we'll use
x-blockdev-reopen so that the interactions between qemu and libvirt
can be tested with the existing code.
Since the usage will be guarded by the for-now unasserted capability
we'll be able to change the called command when the command will be
stabilized.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_monitor.c | 13 +++++++++++++
src/qemu/qemu_monitor.h | 3 +++
src/qemu/qemu_monitor_json.c | 21 +++++++++++++++++++++
src/qemu/qemu_monitor_json.h | 4 ++++
4 files changed, 41 insertions(+)
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index c2a61ec587..3fab31aa38 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -4378,6 +4378,19 @@ qemuMonitorBlockdevAdd(qemuMonitorPtr mon,
}
+int
+qemuMonitorBlockdevReopen(qemuMonitorPtr mon,
+ virJSONValuePtr *props)
+{
+ VIR_DEBUG("props=%p (node-name=%s)", *props,
+ NULLSTR(virJSONValueObjectGetString(*props, "node-name")));
+
+ QEMU_CHECK_MONITOR(mon);
+
+ return qemuMonitorJSONBlockdevReopen(mon, props);
+}
+
+
int
qemuMonitorBlockdevDel(qemuMonitorPtr mon,
const char *nodename)
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 4e06447ffa..23b8d0a650 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -1324,6 +1324,9 @@ int qemuMonitorBlockdevCreate(qemuMonitorPtr mon,
int qemuMonitorBlockdevAdd(qemuMonitorPtr mon,
virJSONValuePtr *props);
+int qemuMonitorBlockdevReopen(qemuMonitorPtr mon,
+ virJSONValuePtr *props);
+
int qemuMonitorBlockdevDel(qemuMonitorPtr mon,
const char *nodename);
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 451e1afef5..0f968b7d36 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -8837,6 +8837,27 @@ qemuMonitorJSONBlockdevAdd(qemuMonitorPtr mon,
}
+int
+qemuMonitorJSONBlockdevReopen(qemuMonitorPtr mon,
+ virJSONValuePtr *props)
+{
+ g_autoptr(virJSONValue) cmd = NULL;
+ g_autoptr(virJSONValue) reply = NULL;
+ virJSONValuePtr pr = g_steal_pointer(props);
+
+ if (!(cmd = qemuMonitorJSONMakeCommandInternal("x-blockdev-reopen", pr)))
+ return -1;
+
+ if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)
+ return -1;
+
+ if (qemuMonitorJSONCheckError(cmd, reply) < 0)
+ return -1;
+
+ return 0;
+}
+
+
int
qemuMonitorJSONBlockdevDel(qemuMonitorPtr mon,
const char *nodename)
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index ed48600b82..5b3bb295eb 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -602,6 +602,10 @@ int qemuMonitorJSONBlockdevAdd(qemuMonitorPtr mon,
virJSONValuePtr *props)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+int qemuMonitorJSONBlockdevReopen(qemuMonitorPtr mon,
+ virJSONValuePtr *props)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+
int qemuMonitorJSONBlockdevDel(qemuMonitorPtr mon,
const char *nodename)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
--
2.24.1
7:39 a.m.
New subject: [PATCH 3/8] qemu: block: implement helpers for blockdev-reopen
Introduce a set of helpers to call blockdev-reopen in certain scenarios
Libvirt will use the QMP command to turn certain members of the backing
chain read-write for bitmap manipulation and we'll also want to use it
to replace/install the backing chain of a qcow2 format node.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_block.c | 121 ++++++++++++++++++++++++++++++++++++++++++
src/qemu/qemu_block.h | 14 +++++
2 files changed, 135 insertions(+)
diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index 152c73f1bf..441b8ec07b 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -2960,3 +2960,124 @@ qemuBlockBitmapsHandleBlockcopy(virStorageSourcePtr src,
return 0;
}
+
+
+/**
+ * qemuBlockReopen:
+ * @vm: domain object
+ * @props: JSON object used as argument of 'blockdev-reopen'
+ * @asyncJob: qemu async job type
+ *
+ * Monitor interaction to call 'blockdev-reopen' @props is consumed on
successful
+ * call and set to NULL if consumed.
+ */
+static int
+qemuBlockReopen(virDomainObjPtr vm,
+ virJSONValuePtr *props,
+ qemuDomainAsyncJob asyncJob)
+{
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+ virQEMUDriverPtr driver = priv->driver;
+ int rc;
+
+ if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
+ return -1;
+
+ rc = qemuMonitorBlockdevReopen(priv->mon, props);
+
+ if (qemuDomainObjExitMonitor(driver, vm) < 0 || rc < 0)
+ return -1;
+
+ return 0;
+}
+
+
+/**
+ * qemuBlockReopenFormat:
+ * @vm: domain object
+ * @src: storage source to reopen
+ * @asyncJob: qemu async job type
+ *
+ * Invokes the 'blockdev-reopen' command on the format layer of @src. This means
+ * that @src must be already properly configured for the desired outcome. The
+ * nodenames of @src are used to identify the specific image in qemu. This
+ * function enters the monitor.
+ */
+int
+qemuBlockReopenFormat(virDomainObjPtr vm,
+ virStorageSourcePtr src,
+ qemuDomainAsyncJob asyncJob)
+{
+ g_autoptr(virJSONValue) reopenprops = NULL;
+
+ /* If we are lacking the object here, qemu might have opened an image with
+ * a node name unknown to us */
+ if (!src->backingStore) {
+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+ _("can't reopen image with unknown presence of backing
store"));
+ return -1;
+ }
+
+ if (!(reopenprops = qemuBlockStorageSourceGetBlockdevProps(src,
src->backingStore)))
+ return -1;
+
+ return qemuBlockReopen(vm, &reopenprops, asyncJob);
+}
+
+
+/**
+ * qemuBlockReopenReadWrite:
+ * @vm: domain object
+ * @src: storage source to reopen
+ * @asyncJob: qemu async job type
+ *
+ * Wrapper that reopens @src read-write. We currently depend on qemu
+ * reopening the storage with 'auto-read-only' enabled for us.
+ * After successful reopen @src's 'readonly' flag is modified. Does nothing
+ * if @src is already read-write.
+ */
+int
+qemuBlockReopenReadWrite(virDomainObjPtr vm,
+ virStorageSourcePtr src,
+ qemuDomainAsyncJob asyncJob)
+{
+ if (!src->readonly)
+ return 0;
+
+ src->readonly = false;
+ if (qemuBlockReopenFormat(vm, src, asyncJob) < 0) {
+ src->readonly = true;
+ return -1;
+ }
+
+ return 0;
+}
+
+
+/**
+ * qemuBlockReopenReadOnly:
+ * @vm: domain object
+ * @src: storage source to reopen
+ * @asyncJob: qemu async job type
+ *
+ * Wrapper that reopens @src read-only. We currently depend on qemu
+ * reopening the storage with 'auto-read-only' enabled for us.
+ * After successful reopen @src's 'readonly' flag is modified. Does nothing
+ * if @src is already read-only.
+ */
+int
+qemuBlockReopenReadOnly(virDomainObjPtr vm,
+ virStorageSourcePtr src,
+ qemuDomainAsyncJob asyncJob)
+{
+ if (src->readonly)
+ return 0;
+
+ src->readonly = true;
+ if (qemuBlockReopenFormat(vm, src, asyncJob) < 0) {
+ src->readonly = false;
+ return -1;
+ }
+
+ return 0;
+}
diff --git a/src/qemu/qemu_block.h b/src/qemu/qemu_block.h
index eab0128d5d..b3d7d0f876 100644
--- a/src/qemu/qemu_block.h
+++ b/src/qemu/qemu_block.h
@@ -228,3 +228,17 @@ qemuBlockBitmapsHandleBlockcopy(virStorageSourcePtr src,
virHashTablePtr blockNamedNodeData,
bool shallow,
virJSONValuePtr *actions);
+
+int
+qemuBlockReopenFormat(virDomainObjPtr vm,
+ virStorageSourcePtr src,
+ qemuDomainAsyncJob asyncJob);
+
+int
+qemuBlockReopenReadWrite(virDomainObjPtr vm,
+ virStorageSourcePtr src,
+ qemuDomainAsyncJob asyncJob);
+int
+qemuBlockReopenReadOnly(virDomainObjPtr vm,
+ virStorageSourcePtr src,
+ qemuDomainAsyncJob asyncJob);
--
2.24.1
7:39 a.m.
New subject: [PATCH 4/8] qemuCheckpointDiscardBitmaps: Reopen images for bitmap modifications
Qemu's bitmap APIs don't reopen the appropriate images read-write for
modification. It's libvirt's duty to reopen them via blockdev-reopen
if we wish to modify the bitmaps.
Use the new helpers to reopen the images for bitmap manipulation.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_checkpoint.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/src/qemu/qemu_checkpoint.c b/src/qemu/qemu_checkpoint.c
index a387e7dfe7..32b0ab0faf 100644
--- a/src/qemu/qemu_checkpoint.c
+++ b/src/qemu/qemu_checkpoint.c
@@ -299,6 +299,9 @@ qemuCheckpointDiscardBitmaps(virDomainObjPtr vm,
if (qemuDomainStorageSourceAccessAllow(driver, vm, src, false, false) < 0)
goto relabel;
+ if (qemuBlockReopenReadWrite(vm, src, QEMU_ASYNC_JOB_NONE) < 0)
+ goto relabel;
+
relabelimages = g_slist_prepend(relabelimages, src);
}
@@ -311,6 +314,7 @@ qemuCheckpointDiscardBitmaps(virDomainObjPtr vm,
for (next = relabelimages; next; next = next->next) {
virStorageSourcePtr src = next->data;
+ ignore_value(qemuBlockReopenReadOnly(vm, src, QEMU_ASYNC_JOB_NONE));
ignore_value(qemuDomainStorageSourceAccessAllow(driver, vm, src, true, false));
}
--
2.24.1
7:39 a.m.
New subject: [PATCH 5/8] qemuCheckpointDiscardBitmaps: Use correct field for checkpoint bitmap name
The code deleting checkpoints needs the name of the parent checkpoint's
disk's bitmap but was using the disk alias instead. This would create
wrong bitmaps after deleting some checkpoints.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_checkpoint.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/qemu/qemu_checkpoint.c b/src/qemu/qemu_checkpoint.c
index 32b0ab0faf..378f6c147e 100644
--- a/src/qemu/qemu_checkpoint.c
+++ b/src/qemu/qemu_checkpoint.c
@@ -283,7 +283,7 @@ qemuCheckpointDiscardBitmaps(virDomainObjPtr vm,
* ancestor. */
if ((parentchkdisk = qemuCheckpointFindActiveDiskInParent(vm, parent,
chkdisk->name)))
- parentbitmap = parentchkdisk->name;
+ parentbitmap = parentchkdisk->bitmap;
if (qemuCheckpointDiscardDiskBitmaps(domdisk->src, blockNamedNodeData,
chkdisk->bitmap, parentbitmap,
--
2.24.1
7:39 a.m.
New subject: [PATCH 6/8] qemuDomainBlockPivot: Move check prior to executing the pivot steps
Move the check whether the job is already synchronised to the beginning
of the function so that we don't try to do some of the steps necessary
for pivoting prior to actually wanting to pivot.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_driver.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 35ade1ef37..76787b6ccc 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -17234,6 +17234,13 @@ qemuDomainBlockPivot(virQEMUDriverPtr driver,
bool blockdev = virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV);
g_autoptr(virJSONValue) actions = NULL;
+ if (job->state != QEMU_BLOCKJOB_STATE_READY) {
+ virReportError(VIR_ERR_BLOCK_COPY_ACTIVE,
+ _("block job '%s' not ready for pivot yet"),
+ job->name);
+ return -1;
+ }
+
switch ((qemuBlockJobType) job->type) {
case QEMU_BLOCKJOB_TYPE_NONE:
case QEMU_BLOCKJOB_TYPE_LAST:
@@ -17271,13 +17278,6 @@ qemuDomainBlockPivot(virQEMUDriverPtr driver,
break;
}
- if (job->state != QEMU_BLOCKJOB_STATE_READY) {
- virReportError(VIR_ERR_BLOCK_COPY_ACTIVE,
- _("block job '%s' not ready for pivot yet"),
- job->name);
- return -1;
- }
-
qemuDomainObjEnterMonitor(driver, vm);
if (blockdev) {
int rc = 0;
--
2.24.1
7:15 a.m.
New subject: [PATCH 6/8] qemuDomainBlockPivot: Move check prior to executing the pivot steps
On a Friday in 2020, Peter Krempa wrote:
Move the check whether the job is already synchronised to the
beginning
of the function so that we don't try to do some of the steps necessary
for pivoting prior to actually wanting to pivot.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_driver.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
Reviewed-by: Ján Tomko <jtomko(a)redhat.com>
Jano
7:39 a.m.
New subject: [PATCH 7/8] qemuDomainBlockCopyCommon: Record updated flags to block job
For a long time we've masked out VIR_DOMAIN_BLOCK_COPY_SHALLOW if
there's no backing chain for the copied disk to simplify the code.
One of the refacors of caused that we no longer update the 'flags'
variable just the local copies. This was okay until in ccd4228afff I
started storing the job flags in the block job data.
Given that we modify how we call qemu we also should modify @flags so
that the correct value is recorded in the block job data.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_driver.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 76787b6ccc..c3215bccca 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -17915,8 +17915,10 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
}
/* clear the _SHALLOW flag if there is only one layer */
- if (!virStorageSourceHasBacking(disk->src))
+ if (!virStorageSourceHasBacking(disk->src)) {
+ flags &= ~VIR_DOMAIN_BLOCK_COPY_SHALLOW;
mirror_shallow = false;
+ }
if (qemuDomainBlockCopyCommonValidateUserMirrorBackingStore(mirror,
mirror_shallow,
--
2.24.1
7:17 a.m.
New subject: [PATCH 7/8] qemuDomainBlockCopyCommon: Record updated flags to block job
On a Friday in 2020, Peter Krempa wrote:
For a long time we've masked out VIR_DOMAIN_BLOCK_COPY_SHALLOW if
there's no backing chain for the copied disk to simplify the code.
One of the refacors of caused that we no longer update the 'flags'
variable just the local copies. This was okay until in ccd4228afff I
started storing the job flags in the block job data.
Given that we modify how we call qemu we also should modify @flags so
that the correct value is recorded in the block job data.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_driver.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
Reviewed-by: Ján Tomko <jtomko(a)redhat.com>
Jano
7:40 a.m.
New subject: [PATCH 8/8] qemu: blockcopy: Allow late opening of the backing chain of a shallow copy
oVirt used a quirk in the pre-blockdev semantics of drive-mirror which
opened the backing chain of the mirror destination only once
'block-job-complete' was called.
Our introduction of blockdev made qemu open the backing chain images
right at the start of the job. This broke oVirt's usage of this API
because they copy the data into the backing chain during the time the
block copy job is running.
Re-introduce late open of the backing chain if qemu supports
blockdev-reopen as we can use that command to install the backing chain
even for an existing image.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_driver.c | 53 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 50 insertions(+), 3 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index c3215bccca..b746cd92d9 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -17229,6 +17229,7 @@ qemuDomainBlockPivot(virQEMUDriverPtr driver,
qemuBlockJobDataPtr job,
virDomainDiskDefPtr disk)
{
+ g_autoptr(qemuBlockStorageSourceChainData) chainattachdata = NULL;
int ret = -1;
qemuDomainObjPrivatePtr priv = vm->privateData;
bool blockdev = virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV);
@@ -17263,6 +17264,7 @@ qemuDomainBlockPivot(virQEMUDriverPtr driver,
if (blockdev && !job->jobflagsmissing) {
g_autoptr(virHashTable) blockNamedNodeData = NULL;
bool shallow = job->jobflags & VIR_DOMAIN_BLOCK_COPY_SHALLOW;
+ bool reuse = job->jobflags & VIR_DOMAIN_BLOCK_COPY_REUSE_EXT;
if (!(blockNamedNodeData = qemuBlockGetNamedNodeData(vm,
QEMU_ASYNC_JOB_NONE)))
return -1;
@@ -17271,6 +17273,17 @@ qemuDomainBlockPivot(virQEMUDriverPtr driver,
blockNamedNodeData,
shallow, &actions) < 0)
return -1;
+
+ /* Open and install the backing chain of 'mirror' late if we support
+ * blockdev-reopen. This is to appease oVirt that wants to copy
+ * data into the backing chain while the top image is being copied
+ * shallow */
+ if (reuse && shallow &&
+ virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV_REOPEN)) {
+ if (!(chainattachdata =
qemuBuildStorageSourceChainAttachPrepareBlockdev(disk->mirror->backingStore,
+
priv->qemuCaps)))
+ return -1;
+ }
}
break;
@@ -17278,6 +17291,23 @@ qemuDomainBlockPivot(virQEMUDriverPtr driver,
break;
}
+ if (chainattachdata) {
+ int rc;
+
+ qemuDomainObjEnterMonitor(driver, vm);
+ rc = qemuBlockStorageSourceChainAttach(priv->mon, chainattachdata);
+ if (qemuDomainObjExitMonitor(driver, vm) < 0 || rc < 0)
+ return -1;
+
+ if (qemuBlockReopenFormat(vm, disk->mirror, QEMU_ASYNC_JOB_NONE) < 0) {
+ qemuDomainObjEnterMonitor(driver, vm);
+ qemuBlockStorageSourceChainDetach(priv->mon, chainattachdata);
+ if (qemuDomainObjExitMonitor(driver, vm) < 0)
+ return -1;
+ return -1;
+ }
+ }
+
qemuDomainObjEnterMonitor(driver, vm);
if (blockdev) {
int rc = 0;
@@ -18027,9 +18057,26 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm,
if (blockdev) {
if (mirror_reuse) {
- if (!(data = qemuBuildStorageSourceChainAttachPrepareBlockdev(mirror,
-
priv->qemuCaps)))
- goto endjob;
+ /* oVirt depended on late-backing-chain-opening semantics the old
+ * qemu command had to copy the backing chain data while the top
+ * level is being copied. To restore this semantics if
+ * blockdev-reopen is supported defer opening of the backing chain
+ * of 'mirror' to the pivot step */
+ if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV_REOPEN)) {
+ g_autoptr(virStorageSource) terminator = virStorageSourceNew();
+
+ if (!terminator)
+ goto endjob;
+
+ if (!(data = qemuBuildStorageSourceChainAttachPrepareBlockdevTop(mirror,
+
terminator,
+
priv->qemuCaps)))
+ goto endjob;
+ } else {
+ if (!(data = qemuBuildStorageSourceChainAttachPrepareBlockdev(mirror,
+
priv->qemuCaps)))
+ goto endjob;
+ }
} else {
if (!(blockNamedNodeData = qemuBlockGetNamedNodeData(vm,
QEMU_ASYNC_JOB_NONE)))
goto endjob;
--
2.24.1
1718
days inactive
1728
days old
10 comments
2 participants
participants (2)
-
Ján Tomko -
Peter Krempa