LVS
lvs-devel
Google
 
Web LinuxVirtualServer.org

Re: [v2 PATCH 0/4] IPVS: Backup Adding Ipv6 and Persistence support

To: Simon Horman <horms@xxxxxxxxxxxx>
Subject: Re: [v2 PATCH 0/4] IPVS: Backup Adding Ipv6 and Persistence support
Cc: Hans Schillstrom <hans.schillstrom@xxxxxxxxxxxx>, LVS-Devel <lvs-devel@xxxxxxxxxxxxxxx>, "wensong@xxxxxxxxxxxx" <wensong@xxxxxxxxxxxx>, "daniel.lezcano@xxxxxxx" <daniel.lezcano@xxxxxxx>
From: Julian Anastasov <ja@xxxxxx>
Date: Mon, 8 Nov 2010 22:59:39 +0200 (EET)

        Hello,

On Mon, 8 Nov 2010, Simon Horman wrote:

today. May be if Hans uses ip_vs_pe_getbyname instead of
ip_vs_pe_get that should solve the request_module problem.

I changed things around a bit in "IPVS: Add persistence engine to
connection entry".

        ip_vs_pe_getbyname() became __ip_vs_pe_getbyname()
        ip_vs_pe_get() became ip_vs_pe_getbyname()
        And ip_vs_pe_get() now just takes a reference on the module if its
        loaded.

So yes I agree, except that __ip_vs_pe_getbyname() is the name
of the function that should be called, which needs to be made
un-static and possibly renamed (again).

Also, to __ip_vs_pe_getbyname() calls try_module_get().
Is that safe from interrupt context?

        Yes, we already use it for cp->app: ip_vs_bind_app ->
tcp_app_conn_bind -> ip_vs_app_inc_get -> ip_vs_app_get

        What should we do if PE module is not loaded
while we are creating connection in backup? We can not
load modules, may be when connection is bound to
dest+svc we should inherit the PE from svc->pe ?

If the modules isn't loaded, then svc->pe can't be non-NULL, right?

        Adding svc will load the PE module, for example:

- backup creates template but there is no PE => cp->pe remains NULL if
        we want to keep conn entry. Option 2 is that we can ignore
        the conn entry if the PE module is not loaded before this step

- svc is added => PE module is loaded (request_module)

- next sync message comes and we bind cp->dest => if cp->pe
is NULL we should set cp->pe to svc->pe. The problem here is
that svc can be added without PE, then this template will not
work as expected.

Regards

--
Julian Anastasov <ja@xxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe lvs-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

<Prev in Thread] Current Thread [Next in Thread>