[libvirt] [PATCH v10 19/19] backup: Prevent snapshots and checkpoints at same time
Eric Blake
eblake at redhat.com
Wed Jul 24 05:56:09 UTC 2019
Earlier patches mentioned that the initial implementation will prevent
snapshots and checkpoints from being used on the same domain at once.
However, the actual restriction is done in this separate patch to make
it easier to lift that restriction via a revert, when we are finally
ready to tackle that integration in the future.
Signed-off-by: Eric Blake <eblake at redhat.com>
---
docs/formatsnapshot.html.in | 4 +++-
src/qemu/qemu_driver.c | 12 ++++++++++++
src/test/test_driver.c | 12 ++++++++++++
tests/virsh-checkpoint | 10 ++++++++++
tests/virsh-snapshot | 10 ++++++++++
tools/virsh.pod | 16 ++++++++++++++++
6 files changed, 63 insertions(+), 1 deletion(-)
diff --git a/docs/formatsnapshot.html.in b/docs/formatsnapshot.html.in
index ced8bbd6db..1935e7351a 100644
--- a/docs/formatsnapshot.html.in
+++ b/docs/formatsnapshot.html.in
@@ -93,7 +93,9 @@
sets that snapshot as current, and the prior current snapshot is
the parent of the new snapshot. Branches in the hierarchy can
be formed by reverting to a snapshot with a child, then creating
- another snapshot.
+ another snapshot. For now, the creation of external snapshots
+ when checkpoints exist is forbidden, although future work will
+ make it possible to integrate these two concepts.
</p>
<p>
The top-level <code>domainsnapshot</code> element may contain
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index d0377d78a9..ca707815d9 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -15749,6 +15749,12 @@ qemuDomainSnapshotCreateXML(virDomainPtr domain,
if (!(vm = qemuDomObjFromDomain(domain)))
goto cleanup;
+ if (virDomainListCheckpoints(vm->checkpoints, NULL, domain, NULL, 0) > 0) {
+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+ _("cannot create snapshot while checkpoint exists"));
+ goto cleanup;
+ }
+
cfg = virQEMUDriverGetConfig(driver);
if (virDomainSnapshotCreateXMLEnsureACL(domain->conn, vm->def, flags) < 0)
@@ -22332,6 +22338,12 @@ static int qemuDomainRename(virDomainPtr dom,
goto endjob;
}
+ if (virDomainListCheckpoints(vm->checkpoints, NULL, dom, NULL, flags) > 0) {
+ virReportError(VIR_ERR_OPERATION_INVALID,
+ "%s", _("cannot rename domain with checkpoints"));
+ goto endjob;
+ }
+
if (virDomainObjListRename(driver->domains, vm, new_name, flags,
qemuDomainRenameCallback, driver) < 0)
goto endjob;
diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index abe51f252a..886d6720db 100644
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -7306,6 +7306,12 @@ testDomainSnapshotCreateXML(virDomainPtr domain,
if (!(vm = testDomObjFromDomain(domain)))
goto cleanup;
+ if (virDomainListCheckpoints(vm->checkpoints, NULL, domain, NULL, 0) > 0) {
+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+ _("cannot create snapshot while checkpoint exists"));
+ goto cleanup;
+ }
+
if (!vm->persistent && (flags & VIR_DOMAIN_SNAPSHOT_CREATE_HALT)) {
virReportError(VIR_ERR_OPERATION_INVALID, "%s",
_("cannot halt after transient domain snapshot"));
@@ -7766,6 +7772,12 @@ testDomainCheckpointCreateXML(virDomainPtr domain,
if (!(vm = testDomObjFromDomain(domain)))
goto cleanup;
+ if (virDomainSnapshotObjListNum(vm->snapshots, NULL, 0) > 0) {
+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+ _("cannot create checkpoint while snapshot exists"));
+ goto cleanup;
+ }
+
if (!virDomainObjIsActive(vm)) {
virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
_("cannot create checkpoint for inactive domain"));
diff --git a/tests/virsh-checkpoint b/tests/virsh-checkpoint
index 6fe5aa4c05..8f964b5822 100755
--- a/tests/virsh-checkpoint
+++ b/tests/virsh-checkpoint
@@ -38,6 +38,10 @@ $abs_top_builddir/tools/virsh --connect test:///default >out 2>err '
checkpoint-create-as test c1
checkpoint-create-as test c3
checkpoint-create-as test c2
+ # snapshots cannot be created while checkpoints exist
+ echo --err marker
+ snapshot-create-as test s1
+ echo --err marker
# Checking tree view (siblings sorted alphabetically)
checkpoint-list test --tree
# Demonstrate list filtering
@@ -77,6 +81,9 @@ Domain checkpoint c1 created
Domain checkpoint c3 created
Domain checkpoint c2 created
+
+
+
c1
|
+- c3
@@ -126,6 +133,9 @@ compare exp out.cooked || fail=1
cat <<EOF > exp || fail=1
error: operation failed: domain moment c1 already exists
+error: marker
+error: Operation not supported: cannot create snapshot while checkpoint exists
+error: marker
EOF
compare exp err || fail=1
diff --git a/tests/virsh-snapshot b/tests/virsh-snapshot
index b23d949f62..fa321d3354 100755
--- a/tests/virsh-snapshot
+++ b/tests/virsh-snapshot
@@ -45,6 +45,10 @@ $abs_top_builddir/tools/virsh --connect test:///default >out 2>err '
snapshot-revert test s1
snapshot-create-as test s7
snapshot-create-as test s8
+ # checkpoints cannot be created while snapshots exist
+ echo --err marker
+ checkpoint-create-as test c1
+ echo --err marker
# Checking tree view (siblings sorted alphabetically)
snapshot-list test --tree
# Current was last one created, but we can change that
@@ -102,6 +106,9 @@ Domain snapshot s4 created
Domain snapshot s7 created
Domain snapshot s8 created
+
+
+
s1
|
+- s3
@@ -175,6 +182,9 @@ compare exp out.cooked || fail=1
cat <<EOF > exp || fail=1
error: operation failed: domain moment s1 already exists
error: marker
+error: Operation not supported: cannot create checkpoint while snapshot exists
+error: marker
+error: marker
error: domain 'test' has no current snapshot
error: marker
EOF
diff --git a/tools/virsh.pod b/tools/virsh.pod
index f58578e3b3..af739bec24 100644
--- a/tools/virsh.pod
+++ b/tools/virsh.pod
@@ -4669,6 +4669,10 @@ a persistent domain. However, for transient domains, snapshot
metadata is silently lost when the domain quits running (whether
by command such as B<destroy> or by internal guest action).
+For now, it is not possible to create snapshots in a domain that has
+checkpoints, although this restriction will be lifted in a future
+release.
+
=item B<snapshot-create-as> I<domain> {[I<--print-xml>]
[I<--no-metadata>] [I<--halt>] [I<--reuse-external>]} [I<name>]
[I<description>] [I<--disk-only> [I<--quiesce>]] [I<--atomic>]
@@ -4735,6 +4739,10 @@ If I<--live> is specified, libvirt takes the snapshot while the guest is
running. This increases the size of the memory image of the external
snapshot. This is currently supported only for external full system snapshots.
+For now, it is not possible to create snapshots in a domain that has
+checkpoints, although this restriction will be lifted in a future
+release.
+
=item B<snapshot-current> I<domain> {[I<--name>] | [I<--security-info>]
| [I<snapshotname>]}
@@ -4943,6 +4951,10 @@ a persistent domain. However, for transient domains, checkpoint
metadata is silently lost when the domain quits running (whether
by command such as B<destroy> or by internal guest action).
+For now, it is not possible to create checkpoints in a domain that has
+snapshots, although this restriction will be lifted in a future
+release.
+
=item B<checkpoint-create-as> I<domain> [I<--print-xml>]
[I<name>] [I<description>] [I<--quiesce>] [I<--diskspec>] B<diskspec>]...
@@ -4966,6 +4978,10 @@ If I<--quiesce> is specified, libvirt will try to use guest agent
to freeze and unfreeze domain's mounted file systems. However,
if domain has no guest agent, checkpoint creation will fail.
+For now, it is not possible to create checkpoints in a domain that has
+snapshots, although this restriction will be lifted in a future
+release.
+
=item B<checkpoint-edit> I<domain> I<checkpointname>
Edit the XML configuration file for I<checkpointname> of a domain.
--
2.20.1
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