Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
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Daniel P. Berrange 925de19ed7 Add a mutex to serialize updates to firewall
The nwfilter conf update mutex previously serialized
updates to the internal data structures for firewall
rules, and updates to the firewall itself. The latter
was recently turned into a read/write lock, and filter
instantiation allowed to proceed in parallel. It was
believed that this was ok, since each filter is created
on a separate iptables/ebtables chain.

It turns out that there is a subtle lock ordering problem
on virNWFilterObjPtr instances. __virNWFilterInstantiateFilter
will hold a lock on the virNWFilterObjPtr it is instantiating.
This in turn invokes virNWFilterInstantiate which then invokes
virNWFilterDetermineMissingVarsRec which then invokes
virNWFilterObjFindByName. This iterates over every single
virNWFilterObjPtr in the list, locking them and checking their
name. So if 2 or more threads try to instantiate a filter in
parallel, they'll all hold 1 lock at the top level in the
__virNWFilterInstantiateFilter method which will cause the
other thread to deadlock in virNWFilterObjFindByName.

The fix is to add an exclusive mutex to serialize the
execution of __virNWFilterInstantiateFilter.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2014-03-10 11:56:45 +00:00
.gnulib@72fb9075b2 maint: update to latest gnulib, for older autoconf 2014-02-21 17:18:34 -07:00
build-aux Make syntax check notice assignments w/o surrounding spaces. 2014-01-20 14:35:26 +01:00
daemon Make sure apparmor is started before libvirtd 2014-03-04 11:07:05 +00:00
docs doc: storage: Explicitly state that it's possible to have non-unique key 2014-03-05 09:51:24 +01:00
examples add support for apparmor in lxc-enter-namespace 2014-03-04 11:15:47 +00:00
gnulib maint: update to latest gnulib 2014-01-01 06:02:47 -07:00
include bhyve: add a basic driver 2014-02-19 14:21:50 +00:00
m4 build: use --with-systemd-daemon as configure option 2014-02-26 05:59:22 -07:00
po add virhostdev files to maintain global state of host devices 2014-03-04 12:28:45 +00:00
src Add a mutex to serialize updates to firewall 2014-03-10 11:56:45 +00:00
tests tests: Fix SELinux tests in VPATH build 2014-03-10 10:20:30 +01:00
tools Fix locking in virsh console 2014-03-10 14:51:32 +04:00
.ctags maint: Make ctags work out of the box 2013-07-18 08:47:21 +02:00
.dir-locals.el build: avoid tabs that failed syntax-check 2012-09-06 09:43:46 -06:00
.gitignore Add tests for virUSBDeviceFind functions 2014-03-03 14:35:22 +01:00
.gitmodules make .gnulib a submodule 2009-07-08 16:17:51 +02:00
.mailmap Autogenerate AUTHORS 2012-10-19 12:44:56 -04:00
AUTHORS.in Add Roman Bogorodskiy to the committers list 2014-02-20 20:51:08 +04:00
autobuild.sh Remove python binding 2013-11-25 16:08:00 +00:00
autogen.sh autogen.sh: Correctly detect .git as a file 2013-08-29 13:19:45 +02:00
bootstrap maint: update to latest gnulib 2014-01-01 06:02:47 -07:00
bootstrap.conf Add helpers for getting env vars in a setuid environment 2013-10-21 14:03:52 +01:00
cfg.mk Add tests for virUSBDeviceFind functions 2014-03-03 14:35:22 +01:00
ChangeLog-old maint: typo fixes 2013-10-22 16:49:32 +01:00
config-post.h build: fix build of virt-login-shell on systems with older gnutls 2013-10-22 09:41:50 -06:00
configure.ac Fix missing char dev lock path case in configure 2014-03-05 22:51:59 +04:00
COPYING maint: follow recommended practice for using LGPL 2013-05-20 14:15:21 -06:00
COPYING.LESSER maint: follow recommended practice for using LGPL 2013-05-20 14:15:21 -06:00
HACKING maint: enforce comma style usage 2013-11-20 09:24:18 -07:00
libvirt.pc.in Add missing 'libvirt_lxc_api' variable in pkg-config file 2013-09-04 14:52:40 +01:00
libvirt.spec.in spec: Let translations be properly updated 2014-03-06 22:18:11 +01:00
Makefile.am Introduce Libvirt Wireshark dissector 2014-01-20 17:09:41 +01:00
Makefile.nonreentrant maint: use LGPL correctly 2013-05-20 14:03:48 -06:00
mingw-libvirt.spec.in Remove python binding 2013-11-25 16:08:00 +00:00
README Correct typos in the documentation (Atsushi SAKAI) 2008-01-24 10:15:13 +00:00
README-hacking maint: relax git minimum version 2010-02-24 14:29:27 -05:00
run.in Remove python binding 2013-11-25 16:08:00 +00:00
TODO Update todo list file to point at bugzilla/website 2010-10-13 16:45:26 +01:00

         LibVirt : simple API for virtualization

  Libvirt is a C toolkit to interact with the virtualization capabilities
of recent versions of Linux (and other OSes). It is free software
available under the GNU Lesser General Public License. Virtualization of
the Linux Operating System means the ability to run multiple instances of
Operating Systems concurrently on a single hardware system where the basic
resources are driven by a Linux instance. The library aim at providing
long term stable C API initially for the Xen paravirtualization but
should be able to integrate other virtualization mechanisms if needed.

Daniel Veillard <veillard@redhat.com>