[libvirt] [PATCHv5 2/3] libvirt/qemu - support persistent modification of qemu disks

[KAMEZAWA Hiroyuki]

On Mon, 21 Mar 2011 16:05:19 +0800
Wen Congyang <wency at cn.fujitsu.com> wrote:

> At 03/16/2011 02:45 PM, KAMEZAWA Hiroyuki Write:
> >>From ddcd9cb499dd73dfc91c9f2cc97c064d6dda17fc Mon Sep 17 00:00:00 2001
> > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
> > Date: Wed, 16 Mar 2011 14:05:21 +0900
> > Subject: [PATCHv5 2/3] libvirt/qemu - support persistent modification of qemu disks
> > 
> > support changes of disks by VIR_DOMAIN_DEVICE_MODIFY_CONFIG
> > for qemu.
> > 
> > Changelog v4->v5:
> >   - moved some functions to domain_conf.c
> >   - added virDomainDefAddImplicitControllers() for ide/scsi
> >   - report OOM.
> >   - clean up.
> > 
> > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
> > ---
> >  src/conf/domain_conf.c   |   22 ++++++++++++++++++++++
> >  src/conf/domain_conf.h   |    3 ++-
> >  src/libvirt_private.syms |    2 ++
> >  src/qemu/qemu_driver.c   |   29 +++++++++++++++++++++++++++++
> >  4 files changed, 55 insertions(+), 1 deletions(-)
> > 
> > diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> > index 16e1291..1d39481 100644
> > --- a/src/conf/domain_conf.c
> > +++ b/src/conf/domain_conf.c
> > @@ -4859,6 +4859,19 @@ virVirtualPortProfileFormat(virBufferPtr buf,
> >      virBufferVSprintf(buf, "%s</virtualport>\n", indent);
> >  }
> >  
> > +int virDomainDiskIndexByName(virDomainDefPtr def, const char *name)
> > +{
> > +    virDomainDiskDefPtr vdisk;
> > +    int i;
> > +
> > +    for (i = 0; i < def->ndisks; i++) {
> > +        vdisk = def->disks[i];
> > +        if (STREQ(vdisk->dst, name))
> > +            return i;
> > +    }
> > +    return -1;
> > +}
> > +
> >  int virDomainDiskInsert(virDomainDefPtr def,
> >                          virDomainDiskDefPtr disk)
> >  {
> > @@ -4930,6 +4943,15 @@ void virDomainDiskRemove(virDomainDefPtr def, size_t i)
> >      }
> >  }
> >  
> > +int virDomainDiskRemoveByName(virDomainDefPtr def, const char *name)
> > +{
> > +    int i = virDomainDiskIndexByName(def, name);
> > +    if (i < 0)
> > +        return -1;
> > +    virDomainDiskRemove(def, i);
> > +    return 0;
> > +}
> > +
> >  
> >  int virDomainControllerInsert(virDomainDefPtr def,
> >                                virDomainControllerDefPtr controller)
> > diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
> > index 30aeccc..320ca13 100644
> > --- a/src/conf/domain_conf.h
> > +++ b/src/conf/domain_conf.h
> > @@ -1261,7 +1261,7 @@ int virDomainCpuSetParse(const char **str,
> >                           int maxcpu);
> >  char *virDomainCpuSetFormat(char *cpuset,
> >                              int maxcpu);
> > -
> > +int virDomainDiskIndexByName(virDomainDefPtr def, const char *name);
> >  int virDomainDiskInsert(virDomainDefPtr def,
> >                          virDomainDiskDefPtr disk);
> >  void virDomainDiskInsertPreAlloced(virDomainDefPtr def,
> > @@ -1269,6 +1269,7 @@ void virDomainDiskInsertPreAlloced(virDomainDefPtr def,
> >  int virDomainDiskDefAssignAddress(virCapsPtr caps, virDomainDiskDefPtr def);
> >  
> >  void virDomainDiskRemove(virDomainDefPtr def, size_t i);
> > +int virDomainDiskRemoveByName(virDomainDefPtr def, const char *name);
> >  
> >  int virDomainControllerInsert(virDomainDefPtr def,
> >                                virDomainControllerDefPtr controller);
> > diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> > index c88d934..1761dfb 100644
> > --- a/src/libvirt_private.syms
> > +++ b/src/libvirt_private.syms
> > @@ -243,11 +243,13 @@ virDomainDiskDefFree;
> >  virDomainDiskDeviceTypeToString;
> >  virDomainDiskErrorPolicyTypeFromString;
> >  virDomainDiskErrorPolicyTypeToString;
> > +virDomainDiskIndexByName;
> >  virDomainDiskInsert;
> >  virDomainDiskInsertPreAlloced;
> >  virDomainDiskIoTypeFromString;
> >  virDomainDiskIoTypeToString;
> >  virDomainDiskRemove;
> > +virDomainDiskRemoveByName;
> >  virDomainDiskTypeFromString;
> >  virDomainDiskTypeToString;
> >  virDomainFSDefFree;
> > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> > index dbd5bd3..d6d7ad0 100644
> > --- a/src/qemu/qemu_driver.c
> > +++ b/src/qemu/qemu_driver.c
> > @@ -4137,8 +4137,27 @@ cleanup:
> >  static int qemuDomainAttachDevicePersistent(virDomainDefPtr vmdef,
> >                                              virDomainDeviceDefPtr newdev)
> >  {
> > +    virDomainDiskDefPtr disk;
> >  
> >      switch(newdev->type) {
> > +    case VIR_DOMAIN_DEVICE_DISK:
> > +        disk = newdev->data.disk;
> > +        if (virDomainDiskIndexByName(vmdef, disk->dst) >= 0) {
> > +            qemuReportError(VIR_ERR_INVALID_ARG,
> > +                            _("target %s already exists."), disk->dst);
> > +            return -1;
> > +        }
> > +        if (virDomainDiskInsert(vmdef, disk)) {
> > +            virReportOOMError();
> > +            return -1;
> > +        }
> > +        if (disk->bus == VIR_DOMAIN_DISK_BUS_VIRTIO) {
> > +            if (qemuDomainAssignPCIAddresses(vmdef) < 0)
> > +                return -1;
> > +        } else if (virDomainDefAddImplicitControllers(vmdef) < 0)
> > +            return -1;
> 
> When qemuDomainAssignPCIAddresses() or virDomainDefAddImplicitControllers() failed,
> we should remove disk from vmdef, otherwise, it will cause libvirtd crashed.
> 

By returning -1, the vmdef is not saved and no one will see this modified
vmdef (because the task is inactive here.)

Do I need to care ?

Thanks,
-Kame