On Thu, Aug 19, 2010 at 02:49:34PM +0200, soren@xxxxxxxxxxx wrote:
> From: Soren Hansen <soren@xxxxxxxxxxx>
>
> UML supports hot plugging and unplugging of various devices. This patch
> exposes this functionality for disks.
Nice, I had no idea they supported that.
> Signed-off-by: Soren Hansen <soren@xxxxxxxxxxx>
> ---
> src/uml/uml_driver.c | 223 +++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 221 insertions(+), 2 deletions(-)
>
> diff --git a/src/uml/uml_driver.c b/src/uml/uml_driver.c
> index 04493ba..a09bc60 100644
> --- a/src/uml/uml_driver.c
> +++ b/src/uml/uml_driver.c
> @@ -1686,6 +1686,225 @@ cleanup:
> }
>
>
> +static inline void umlShrinkDisks(virDomainDefPtr def, size_t i)
> +{
> + if (def->ndisks > 1) {
> + memmove(def->disks + i,
> + def->disks + i + 1,
> + sizeof(*def->disks) *
> + (def->ndisks - (i + 1)));
> + def->ndisks--;
> + if (VIR_REALLOC_N(def->disks, def->ndisks) < 0) {
> + /* ignore, harmless */
> + }
> + } else {
> + VIR_FREE(def->disks);
> + def->ndisks = 0;
> + }
> +}
Since this code is already used in the QEMU driver, I think we
should just put it straight into src/conf/domain_conf.c so we
can share it. 'virDomainDiskRemove' is probably a more accurate
name than ShrinkDisks.
> +
> +
> +static int umlDomainAttachUmlDisk(struct uml_driver *driver,
> + virDomainObjPtr vm,
> + virDomainDiskDefPtr disk)
> +{
> + int i, ret;
> + char *cmd = NULL;
> + char *reply;
> +
> + for (i = 0 ; i < vm->def->ndisks ; i++) {
> + if (STREQ(vm->def->disks[i]->dst, disk->dst)) {
> + umlReportError(VIR_ERR_OPERATION_FAILED,
> + _("target %s already exists"), disk->dst);
> + return -1;
> + }
> + }
> +
> + if (!disk->src) {
> + umlReportError(VIR_ERR_INTERNAL_ERROR,
> + "%s", _("disk source path is missing"));
> + goto error;
> + }
> +
> + if (virAsprintf(&cmd, "config %s=%s", disk->dst, disk->src) < 0) {
> + virReportOOMError();
> + return -1;
> + }
> +
> + if (umlMonitorCommand(driver, vm, cmd, &reply) < 0)
> + return -1;
Needs to be a 'goto error' to avoid leaking 'cmd'
> +
> + if (VIR_REALLOC_N(vm->def->disks, vm->def->ndisks+1) < 0) {
> + virReportOOMError();
> + goto error;
> + }
> +
> + if (ret < 0)
> + goto error;
> +
> + virDomainDiskInsertPreAlloced(vm->def, disk);
> +
> + VIR_FREE(cmd);
> +
> + return 0;
> +
> +error:
> +
> + VIR_FREE(cmd);
> +
> + return -1;
> +}
> + dev = virDomainDeviceDefParse(driver->caps, vm->def, xml,
> + VIR_DOMAIN_XML_INACTIVE);
> + if (dev == NULL)
> + goto cleanup;
> +
> + if (dev->type == VIR_DOMAIN_DEVICE_DISK &&
> + dev->data.disk->device == VIR_DOMAIN_DISK_DEVICE_DISK) {
> + if (dev->data.disk->bus == VIR_DOMAIN_DISK_BUS_UML)
> + ret = umlDomainDetachUmlDisk(driver, vm, dev);
> + else {
> + umlReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> + _("This type of disk cannot be hot unplugged"));
> + }
> + } else {
> + umlReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> + "%s", _("This type of device cannot be hot unplugged"));
> + }
> +
> +cleanup:
> + virDomainDeviceDefFree(dev);
> + if (vm)
> + virDomainObjUnlock(vm);
> + umlDriverUnlock(driver);
> + return ret;
> +}
> +
>
> static int umlDomainGetAutostart(virDomainPtr dom,
> int *autostart) {
> @@ -1900,9 +2119,9 @@ static virDriver umlDriver = {
> umlDomainStartWithFlags, /* domainCreateWithFlags */
> umlDomainDefine, /* domainDefineXML */
> umlDomainUndefine, /* domainUndefine */
> - NULL, /* domainAttachDevice */
> + umlDomainAttachDevice, /* domainAttachDevice */
> NULL, /* domainAttachDeviceFlags */
> - NULL, /* domainDetachDevice */
> + umlDomainDetachDevice, /* domainDetachDevice */
> NULL, /* domainDetachDeviceFlags */
You should also implement the DeviceFlags variants at
the same time. You can just do a dumb wrapper like QEMU
driver does, for simplicity.
Regards,
Daniel
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