[libvirt] [PATCH v2 0/3] ensure diskchain is not broken on guest bootup

[Guannan Ren]

v1->v2: Add a helper function qemuDiskChainCheckBroken to check diskchain
        after invoking qemuDomainDetermineDiskChain()

This patchset try to check whether the diskchain is broken or not when domain
boot up. If dischain is broken, report like:

virsh start rhel6qcow2
error: Failed to start domain rhel6qcow2
error: invalid argument: Backing file '/var/lib/libvirt/images/thirddisk' of \
       image '/var/lib/libvirt/images/thirddisk.snap3' is missing.

For storage pool, it still can list volumes out even if their diskchain is broken

Guannan Ren(3)
 qemu: refactor qemuDomainCheckDiskPresence for only disk presence check
 qemu: add helper functions for diskchain checking
 qemu: check presence of each disk and its backing file as well

 src/libvirt_private.syms  |   1 +
 src/qemu/qemu_domain.c    | 133 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----------------------------
 src/qemu/qemu_domain.h    |   3 ++
 src/qemu/qemu_process.c   |   6 ----
 src/util/virstoragefile.c |  47 +++++++++++++++++++++++++++++++
 src/util/virstoragefile.h |   2 ++
 6 files changed, 141 insertions(+), 51 deletions(-)