Re: [libvirt] [PATCH 5/8] UndefineFlags: Implement qemu driver handling
于 2011年07月14日 02:01, Eric Blake 写道:
On 07/13/2011 04:19 AM, Osier Yang wrote:
> ---
> src/qemu/qemu_driver.c | 31 +++++++++++++++++++++++++++----
> 1 files changed, 27 insertions(+), 4 deletions(-)
>
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index f962e2c..a9f6986 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -2402,10 +2402,8 @@ cleanup:
> static char *
> qemuDomainManagedSavePath(struct qemud_driver *driver, virDomainObjPtr vm) {
> char *ret;
> - char uuidstr[VIR_UUID_STRING_BUFLEN];
> - virUUIDFormat(vm->def->uuid, uuidstr);
>
> - if (virAsprintf(&ret, "%s/%s.save", driver->saveDir,
uuidstr)< 0) {
> + if (virAsprintf(&ret, "%s/%s.save", driver->saveDir,
vm->def->name)< 0) {
This hunk won't apply to existing libvirt.git. Did you forget to rebase
out your first attempt?
Ah, yes.
> @@ -4312,6 +4315,20 @@ static int
qemudDomainUndefine(virDomainPtr dom) {
> goto cleanup;
> }
>
> + if (flags& VIR_DOMAIN_UNDEFINE_MANAGED_STATE) {
> + name = qemuDomainManagedSavePath(driver, vm);
> +
> + if (name == NULL)
> + goto cleanup;
> +
> + if (virFileExists(name)&& (unlink(name)< 0)) {
> + qemuReportError(VIR_ERR_INTERNAL_ERROR,
> + _("failed on removing domain managed state "
> + "file '%s'"), name);
> + goto cleanup;
> + }
> + }
I think we need to explicitly reject attempts to undefine a domain while
a state file exists. That is, I think this logic needs to be:
name = qemuDomainManagedSavePath(driver, vm);
if (name == NULL)
goto cleanup;
if (virFileExists(name)) {
if (flags& VIR_DOMAIN_UNDEFINE_MANAGED_STATE) {
if (unlink(name)< 0) {
error - failed to remove
}
} else {
error - refusing to undefine with managed state file present
}
}
Yes, it will change existing behavior (previously, you could undefine a
domain and leave the state file behind), but that was unsafe, and this
is arguably a bug fix. The default should be as safe as possible, with
the flags (VIR_DOMAIN_UNDEFINE_MANAGED_STATE) in place to make things
faster.
This answer my question in 3/8
> @@ -8487,6 +8509,7 @@ static virDriver qemuDriver = {
> .domainCreateWithFlags = qemudDomainStartWithFlags, /* 0.8.2 */
> .domainDefineXML = qemudDomainDefine, /* 0.2.0 */
> .domainUndefine = qemudDomainUndefine, /* 0.2.0 */
> + .domainUndefineWithFlags = qemudDomainUndefineWithFlags, /* 0.9.4 */
Also, I think that for every hypervisor that supports domainUndefine, we
should add a (trivial) domainUndefine[With]Flags wrapper, so that the
new API is available everywhere in 0.9.4, but do that as a separate patch.
Agree, even if other hypervisors except libxl and qemu don't support
managed saving.
I'm about to post a series to add virDomainSaveFlags, which might
serve
as an example for what I'm thinking about. That series will add a
no-semantic-change wrapper in the first commit, and only later changes
the qemu wrapper to learn to honor a new flag value.