Re: [libvirt] [PATCH v5 3/3] libvirtd: fix crash on termination
On 12/14/2017 06:58 AM, Nikolay Shirokovskiy wrote:
Hi, all.
I looked over thread for this particular patch again and found resolution is we:
1. make a more sane cleanup order in libvirtd's main function (already done by [1]).
2. rewrite linked series [2] by introducing event loop closing callback (ok)
But there is no resolution on this patch itself if I am not mistaken and
it is not pushed too.
LINKS
[1] [PATCH 0/5] libvirtd: Adjustments to startup and cleanup processing
https://www.redhat.com/archives/libvir-list/2017-November/msg00293.html
The cover letter of this essentially states the cleanup is an
alternative based upon the review of "this" series' 3/3 patch (IOW: this
patch).
So I agree w/ Erik - the (last) memory strand that I have left on this
indicates that the virHashRemoveAll isn't necessary in virNetDaemonClose
because we've properly order the cleanup with the new patch 4 from [1].
[2] [PATCH 0/4] libvirtd: fix hang on termination in qemu driver
https://www.redhat.com/archives/libvir-list/2017-October/msg01134.html
I responded to this series' cover letter with:
https://www.redhat.com/archives/libvir-list/2017-November/msg00455.html
in order to attempt to move the conversations found in "this" series to
that series rather than clouding "this" series with information
belonging to that series.
So the question *now* is - did you find a condition/case with [1]
patches applied, but [2] patches not applied (IOW: current top) where
something isn't being Unref'd properly?
John
Nikolay
On 30.10.2017 14:14, John Ferlan wrote:
> From: Nikolay Shirokovskiy <nshirokovskiy(a)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(a)redhat.com>
> ---
> src/rpc/virnetdaemon.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/src/rpc/virnetdaemon.c b/src/rpc/virnetdaemon.c
> index 8c21414897..33bd8e3b06 100644
> --- a/src/rpc/virnetdaemon.c
> +++ b/src/rpc/virnetdaemon.c
> @@ -881,6 +881,7 @@ virNetDaemonClose(virNetDaemonPtr dmn)
> virObjectLock(dmn);
>
> virHashForEach(dmn->servers, daemonServerClose, NULL);
> + virHashRemoveAll(dmn->servers);
>
> virObjectUnlock(dmn);
> }
>