On Tue, 2012-05-22 at 16:40 +0400, Stanislav Kinsbursky wrote:
> Client have to be initialized prior to adding it to per-net clients list,
> because otherwise there are races, shown below:
>
> CPU#0 CPU#1
> _____ _____
>
> nfs_get_client
> nfs_alloc_client
> list_add(..., nfs_client_list)
> rpc_fill_super
> rpc_pipefs_event
> nfs_get_client_for_event
> __rpc_pipefs_event
> (clp->cl_rpcclient is uninitialized)
> BUG()
> init_client
> clp->cl_rpcclient = ...
>
Why not simply change nfs_get_client_for_event() so that it doesn't
touch nfs_clients that have clp->cl_cons_state!=NFS_CS_READY?
That should ensure that it doesn't touch nfs_clients that failed to
initialise and/or are still in the process of being initialised.
Cheers
Trond
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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