Re: [libvirt] [PATCH v3] qemu: qemuDomainRename and virDomainObjListNumOfDomains ABBA deadlock fix

On 01.02.2016 10:33, Nikolay Shirokovskiy wrote: > A pretty nasty deadlock occurs while trying to rename a VM in parallel > with virDomainObjListNumOfDomains. > The short description of the problem is as follows: > > Thread #1: > > qemuDomainRename: > ------> aquires domain lock by qemuDomObjFromDomain > ---------> waits for domain list lock in any of the listed functions: > - virDomainObjListFindByName > - virDomainObjListRenameAddNew > - virDomainObjListRenameRemove > > Thread #2: > > virDomainObjListNumOfDomains: > ------> aquires domain list lock > ---------> waits for domain lock in virDomainObjListCount > > Introduce generic virDomainObjListRename function for renaming domains. > It aquires list lock in right order to avoid deadlock. Callback is used > to make driver specific domain updates. > > Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy(a)virtuozzo.com&gt; > --- > src/conf/virdomainobjlist.c | 98 +++++++++++++++++++----------- > src/conf/virdomainobjlist.h | 16 +++-- > src/libvirt_private.syms | 3 +- > src/qemu/qemu_driver.c | 142 ++++++++++++++++++++------------------------ > 4 files changed, 142 insertions(+), 117 deletions(-) Looking good. ACK. But I rather wait couple of moments in case others would like to express their feelings. Michal