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24d194ad59
This patch fixes some flawed logic around ref counting the libxlMigrationDstArgs object. First, when adding sockets to the event loop with virNetSocketAddIOCallback(), the generic virObjectFreeCallback() was registered as a free function, with libxlMigrationDstArgs as its parameter. A reference was also taken on libxlMigrationDstArgs for each successful call to virNetSocketAddIOCallback(). The rational behind this logic was that the libxlMigrationDstArgs object had to out-live the socket objects. But virNetSocketAddIOCallback() already takes a reference on socket objects, ensuring their life until removed from the event loop and unref'ed in virNetSocketEventFree(). We only need to ensure libxlMigrationDstArgs lives until libxlDoMigrateReceive() finishes, which can be done by simply unref'ing libxlMigrationDstArgs at the end of libxlDoMigrateReceive(). The second flaw was unref'ing the sockets in the failure path of libxlMigrateReceive() and at the end of libxlDoMigrateReceive(). As mentioned above, the sockets are already unref'ed by virNetSocketEventFree() when removed from the event loop. Attempting to unref the socket a second time resulted in a libvirtd crash since the socket was previously unref'ed and disposed. Signed-off-by: Jim Fehlig <jfehlig@suse.com> (cherry picked from commit 44a54eb073d2ae52ebf1661ae73bb1f0f98599f9)
libvirt library code README
===========================
The directory provides the bulk of the libvirt codebase. Everything
except for the libvirtd daemon and client tools. The build uses a
large number of libtool convenience libraries - one for each child
directory, and then links them together for the final libvirt.so,
although some bits get linked directly to libvirtd daemon instead.
The files directly in this directory are supporting the public API
entry points & data structures.
There are two core shared modules to be aware of:
* util/ - a collection of shared APIs that can be used by any
code. This directory is always in the include path
for all things built
* conf/ - APIs for parsing / manipulating all the official XML
files used by the public API. This directory is only
in the include path for driver implementation modules
* vmx/ - VMware VMX config handling (used by esx/ and vmware/)
Then there are the hypervisor implementations:
* bhyve - bhyve - The BSD Hypervisor
* esx/ - VMware ESX and GSX support using vSphere API over SOAP
* hyperv/ - Microsoft Hyper-V support using WinRM
* lxc/ - Linux Native Containers
* openvz/ - OpenVZ containers using cli tools
* phyp/ - IBM Power Hypervisor using CLI tools over SSH
* qemu/ - QEMU / KVM using qemu CLI/monitor
* remote/ - Generic libvirt native RPC client
* test/ - A "mock" driver for testing
* uml/ - User Mode Linux
* vbox/ - Virtual Box using native API
* vmware/ - VMware Workstation and Player using the vmrun tool
* xen/ - Xen using hypercalls, XenD SEXPR & XenStore
* xenapi/ - Xen using libxenserver
Finally some secondary drivers that are shared for several HVs.
Currently these are used by LXC, OpenVZ, QEMU, UML and Xen drivers.
The ESX, Hyper-V, Power Hypervisor, Remote, Test & VirtualBox drivers all
implement the secondary drivers directly
* cpu/ - CPU feature management
* interface/ - Host network interface management
* network/ - Virtual NAT networking
* nwfilter/ - Network traffic filtering rules
* node_device/ - Host device enumeration
* secret/ - Secret management
* security/ - Mandatory access control drivers
* storage/ - Storage management drivers
Since both the hypervisor and secondary drivers can be built as
dlopen()able modules, it is *FORBIDDEN* to have build dependencies
between these directories. Drivers are only allowed to depend on
the public API, and the internal APIs in the util/ and conf/
directories