[Qemu-devel] [PATCH 0/3] qga: vss-win32: Fix interference with other VSS requesters

[Tomoki Sekiyama <tomoki.sekiyama@hds.com>]

Current functionarity of qemu-ga VSS provider is limited to implement
filesystems freeze, and doesn't support the creation of shadow copies
within the guest.
However, when no other hardware snapshot provider is installed, VSS may
choose qemu-ga VSS provider to create shadow copies and fail with
VSS_E_UNEXPECTED_PROVIDER_ERROR.
Similar issue occurs when the requester deletes shadow copies.

This patchset fix this issue by telling VSS that the volume is not
supported by qemu-ga VSS provider when it is kicked by other requesters.

It also fixes wrong error handling around OpenEvent/CreateEvent WinAPI,
which returns NULL instead of INVALID_HANDLE_VALUE on errors.

https://bugzilla.redhat.com/show_bug.cgi?id=1036341

---
Tomoki Sekiyama (3):
      qga: vss-win32: Use NULL as an invalid pointer for OpenEvent and CreateEvent
      qga: vss-win32: Fix interference with snapshot creation by other VSS requesters
      qga: vss-win32: Fix interference with snapshot deletion by other VSS request


 qga/vss-win32/provider.cpp  |   21 ++++++++++---
 qga/vss-win32/requester.cpp |   70 ++++++++++++++++++++-----------------------
 2 files changed, 49 insertions(+), 42 deletions(-)

-- 
Tomoki Sekiyama