[libvirt] [PATCH v3 0/9] qemu: Add quorum support to libvirt

Matthias Gatto matthias.gatto at outscale.com
Tue Mar 3 09:45:35 UTC 2015


On Thu, Feb 26, 2015 at 5:04 PM, Peter Krempa <pkrempa at redhat.com> wrote:
> On Mon, Feb 23, 2015 at 14:18:31 +0100, Matthias Gatto wrote:
>> On Tue, Feb 10, 2015 at 4:43 PM, Matthias Gatto
>> <matthias.gatto at outscale.com> wrote:
>> > The purpose of these patches is to introduce quorum for libvirt
>> > I've try to follow this proposal:
>> > http://www.redhat.com/archives/libvir-list/2014-May/msg00533.html
>> >
>> > This feature ask for 6 task:
>> >
>> > 1) Allow a _virStorageSource to contain more than one backing store.
>> >
>> > Because all the actual libvirt code use the backingStore field
>> > as a pointer and we needs want to change that, I've decide to encapsulate
>> > the backingStore field to simplifie the array manipulation.
>> >
>> > 2) Add the missing field a quorum need in _virStorageSource and
>> > the VIR_STORAGE_TYPE_QUORUM and VIR_STORAGE_FILE_QUORUM in
>> > their respectives enums.
>> >
>> > 3) Parse and format the xml
>> > Because a quorum allows to have more than one backing store at the same level
>> > we need to change virDomainDiskDefFormat and virDomainDiskDefParseXML
>> > to call virDomainDiskBackingStoreFormat and virDomainDiskBackingStoreParse
>> > in a loop.
>> > virDomainDiskBackingStoreFormat and virDomainDiskBackingStoreParse can
>> > call themself recursively in a loop because a quorum can contain another
>> > quorum
>> >
>> > 4) Add nodename
>> > We need to add nodename support in _virStorageSource because qemu
>> > use them for their child.
>> >
>> > 5) Build qemu string
>> > As for the xml, we have to call the function which create quorum recursively.
>> > But this task have the problem explained here:
>> > http://www.redhat.com/archives/libvir-list/2014-October/msg00529.html
>> > The _virStorageSource missing some informations that can be passed to
>> > a child, and therefore this version of quorum is incomplet.
>> >
>> > 6) Allow to hotplug/change a disk in a quorum
>> > This part is not present in these patches because for this task
>> > we have to use blockdev-add, and currently libvirt use
>> > device_add for hotpluging that doesn't allow to hotplug quorum childs.
>> >
>> > There is 3 way to handle this problem:
>> >       1) create a virDomainBlockDevAdd function in libvirt witch call
>> >       blockdev-add.
>> >
>> >       2) use blockdev-add instead of device_add in qemuMonitorJSONAddDevice
>> >
>> >       3) write a hack which uses blockdev-add when only attaching quorum
>> >       (but i'm pretty sure this solution is not the good one)
>> >
>> > V2:
>> >         -Rebase on master
>> >         -Add Documentation
>> >
>> > V3:
>> >         -Transforme the backingStore field in virStorageSource into
>> >          an array of pointer instead of a pointer
>> >         -Modify virStorageSourceSetBackingStore to allow it to expand
>> >          the backingStore size.
>> >
>> > Matthias Gatto (9):
>> >   virstoragefile: Add virStorageSourceGetBackingStore
>> >   virstoragefile: Always use virStorageSourceGetBackingStore to get
>> >     backing store
>> >   virstoragefile: Add virStorageSourceSetBackingStore
>> >   virstoragefile: Always use virStorageSourceSetBackingStore to set
>> >     backing store
>> >   virstoragefile: change backingStore to backingStores.
>> >   virstoragefile: Add quorum in virstoragefile
>> >   domain_conf: Read and Write quorum config
>> >   qemu: Add quorum support in qemuBuildDriveDevStr
>> >   virstoragefile: Add node-name
>> >
>> >  docs/formatdomain.html.in             |  27 ++++-
>> >  docs/schemas/domaincommon.rng         |  96 +++++++++++------
>> >  docs/schemas/storagecommon.rng        |   1 +
>> >  docs/schemas/storagevol.rng           |   1 +
>> >  src/conf/domain_conf.c                | 195 ++++++++++++++++++++++++++--------
>> >  src/conf/storage_conf.c               |  23 ++--
>> >  src/libvirt_private.syms              |   2 +
>> >  src/qemu/qemu_cgroup.c                |   4 +-
>> >  src/qemu/qemu_command.c               | 114 ++++++++++++++++++++
>> >  src/qemu/qemu_domain.c                |   2 +-
>> >  src/qemu/qemu_driver.c                |  30 +++---
>> >  src/qemu/qemu_migration.c             |   1 +
>> >  src/security/security_dac.c           |   2 +-
>> >  src/security/security_selinux.c       |   4 +-
>> >  src/security/virt-aa-helper.c         |   2 +-
>> >  src/storage/storage_backend.c         |  33 +++---
>> >  src/storage/storage_backend_fs.c      |  36 ++++---
>> >  src/storage/storage_backend_gluster.c |  10 +-
>> >  src/storage/storage_backend_logical.c |  15 ++-
>> >  src/storage/storage_driver.c          |   2 +-
>> >  src/util/virstoragefile.c             | 116 +++++++++++++++++---
>> >  src/util/virstoragefile.h             |  12 ++-
>> >  tests/virstoragetest.c                |  18 ++--
>> >  23 files changed, 573 insertions(+), 173 deletions(-)
>> >
>> > --
>> > 1.8.3.1
>> >
>>
>> ping
>
> Sorry for taking so long. I was pretty busy in the last time and need to
> switch context to the storage part of libvirt again at first.
>
> I have this series on the radar and will try to review it once I get rid
> of some stuff.
>
> Peter

ok,
Thank you




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