[libvirt] [PATCH v4 2/2] libvirtd: fix crash on termination

[Nikolay Shirokovskiy]

On 27.10.2017 08:26, John Ferlan wrote:
> From: Nikolay Shirokovskiy <nshirokovskiy at virtuozzo.com>
> 
> The problem is incorrect order of qemu driver shutdown and shutdown
> of netserver threads that serve client requests (thru qemu driver
> particularly).
> 
> Net server threads are shutdown upon dispose which is triggered
> by last daemon object unref at the end of main function. At the same
> time qemu driver is shutdown earlier in virStateCleanup. As a result
> netserver threads see invalid driver object in the middle of request
> processing.
> 
> Let's move shutting down netserver threads earlier to virNetDaemonClose.
> 
> Note: order of last daemon unref and virStateCleanup
> is introduced in 85c3a182 for a valid reason.
> 
> Signed-off-by: John Ferlan <jferlan at redhat.com>
> ---
>  src/rpc/virnetdaemon.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/src/rpc/virnetdaemon.c b/src/rpc/virnetdaemon.c
> index d970c47ad4..7cb3214166 100644
> --- a/src/rpc/virnetdaemon.c
> +++ b/src/rpc/virnetdaemon.c
> @@ -882,6 +882,8 @@ virNetDaemonClose(virNetDaemonPtr dmn)
>      virObjectLock(dmn);
>  
>      virHashForEach(dmn->servers, daemonServerClose, NULL);
> +    virHashRemoveAll(dmn->servers);
> +    dmn->servers = NULL;

Setting NULL is not good, we leak hash table memory. Originally I call virHashFree instead of
virHashRemoveAll thus this line. But calling virHashFree earlier then dispose is dangerous
I agee with you here, virHashRemoveAll is better.

>  
>      virObjectUnlock(dmn);
>  }
>