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path: root/qga/vss-win32/provider.cpp
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2014-02-23qga: vss-win32: Fix interference with snapshot deletion by other VSS requestTomoki Sekiyama1-1/+3
When a VSS requester such as vshadow.exe or diskshadow.exe requests to delete snapshots, qemu-ga VSS provider's DeleteSnapshots() is also called and returns E_NOTIMPL, that makes the deletion fail. To avoid this issue, return S_OK and set values that represent no snapshots are deleted by qemu-ga VSS provider. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com> Reviewed-by: Gal Hammer <ghammer@redhat.com> Reviewed-by: Yan Vugenfirer <yvugenfi@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2014-02-23qga: vss-win32: Fix interference with snapshot creation by other VSS requestersTomoki Sekiyama1-1/+10
When a VSS requester such as vshadow.exe or diskshadow.exe requests to create disk snapshots, Windows may choose qemu-ga VSS provider if it is only provider registered on the system. However, because it provides only a function to freeze the filesystem, the snapshotting fails. This patch adds a check into CQGAVssProvider::IsVolumeSupported() to reject the request from other VSS requesters, so that the other provider is chosen. The check of requester is done by confirming event channels between qemu-ga's requester and provider established. To ensure that the events are initialized when CQGAVssProvider::IsVolumeSupported() is called, it moves the initialization earlier. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com> Reviewed-by: Gal Hammer <ghammer@redhat.com> Reviewed-by: Yan Vugenfirer <yvugenfi@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2014-02-23qga: vss-win32: Use NULL as an invalid pointer for OpenEvent and CreateEventTomoki Sekiyama1-3/+3
OpenEvent and CreateEvent WinAPI return NULL when failed to open/create events handles, instead of INVALID_HANDLE_VALUE (although their return types are HANDLE). This replaces INVALID_HANDLE_VALUE related to event handles with NULL. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com> Reviewed-by: Gal Hammer <ghammer@redhat.com> Reviewed-by: Yan Vugenfirer <yvugenfi@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-09-09qemu-ga: Add Windows VSS provider and requester as DLLTomoki Sekiyama1-0/+523
Adds VSS provider and requester as a qga-vss.dll, which is loaded by Windows VSS service as well as by qemu-ga. "provider.cpp" implements a basic stub of a software VSS provider. Currently, this module only relays a frozen event from VSS service to the agent, and thaw event from the agent to VSS service, to block VSS process to keep the system frozen while snapshots are taken at the host. To register the provider to the guest system as COM+ application, the type library (.tlb) for qga-vss.dll is required. To build it from COM IDL (.idl), VisualC++, MIDL and stdole2.tlb in Windows SDK are required. This patch also adds pre-compiled .tlb file in the repository in order to enable cross-compile qemu-ga.exe for Windows with VSS support. "requester.cpp" provides the VSS requester to kick the VSS snapshot process. Qemu-ga.exe works without the DLL, although fsfreeze features are disabled. These functions are only supported in Windows 2003 or later. In older systems, fsfreeze features are disabled. In several versions of Windows which don't support attribute VSS_VOLSNAP_ATTR_NO_AUTORECOVERY, DoSnapshotSet fails with error VSS_E_OBJECT_NOT_FOUND. In this patch, we just ignore this error. To solve this fundamentally, we need a framework to handle mount writable snapshot on guests, which is required by VSS auto-recovery feature (cleanup phase after a snapshot is taken). Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>