Re: [PATCH v2 10/49] nfs41: create NFSv3 DS connection if specified

[Anna Schumaker <Anna.Schumaker@netapp.com>]

Hey Tom and Peng,

On 12/24/2014 02:12 AM, Tom Haynes wrote:
> From: Peng Tao <tao.peng@primarydata.com>
> 
> Signed-off-by: Peng Tao <tao.peng@primarydata.com>
> Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>
> ---
>  fs/nfs/pnfs_dev.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 51 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/nfs/pnfs_dev.c b/fs/nfs/pnfs_dev.c
> index 56f5c16..655333d 100644
> --- a/fs/nfs/pnfs_dev.c
> +++ b/fs/nfs/pnfs_dev.c
> @@ -615,7 +615,44 @@ static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
>  	wake_up_bit(&ds->ds_state, NFS4DS_CONNECTING);
>  }
>  
> -static int _nfs4_pnfs_ds_connect(struct nfs_server *mds_srv,
> +static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
> +				 struct nfs4_pnfs_ds *ds,
> +				 unsigned int timeo,
> +				 unsigned int retrans,
> +				 rpc_authflavor_t au_flavor)
> +{
> +	struct nfs_client *clp = ERR_PTR(-EIO);
> +	struct nfs4_pnfs_ds_addr *da;
> +	int status = 0;
> +
> +	dprintk("--> %s DS %s au_flavor %d\n", __func__,
> +		ds->ds_remotestr, au_flavor);
> +
> +	list_for_each_entry(da, &ds->ds_addrs, da_node) {
> +		dprintk("%s: DS %s: trying address %s\n",
> +			__func__, ds->ds_remotestr, da->da_remotestr);
> +
> +		clp = nfs3_set_ds_client(mds_srv->nfs_client,
> +					(struct sockaddr *)&da->da_addr,
> +					da->da_addrlen, IPPROTO_TCP,
> +					timeo, retrans, au_flavor);
> +		if (!IS_ERR(clp))
> +			break;
> +	}
> +
> +	if (IS_ERR(clp)) {
> +		status = PTR_ERR(clp);
> +		goto out;
> +	}
> +
> +	smp_wmb();
> +	ds->ds_clp = clp;
> +	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
> +out:
> +	return status;
> +}
> +
> +static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
>  				 struct nfs4_pnfs_ds *ds,
>  				 unsigned int timeo,
>  				 unsigned int retrans,
> @@ -674,8 +711,19 @@ void nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
>  	if (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) == 0) {
>  		int err = 0;
>  
> -		err = _nfs4_pnfs_ds_connect(mds_srv, ds, timeo, retrans,
> -					    minor_version, au_flavor);
> +		if (version == 3) {
> +			err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo,
> +						       retrans, au_flavor);
> +		} else if (version == 4) {
> +			err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo,
> +						       retrans, minor_version,
> +						       au_flavor);

Is it possible to do this with NFS-version specific function pointers, similar to how we have the rpc_ops array?

Thanks,
Anna

> +		} else {
> +			dprintk("%s: unsupported DS version %d\n", __func__,
> +				version);
> +			err = -EPROTONOSUPPORT;
> +		}
> +
>  		if (err)
>  			nfs4_mark_deviceid_unavailable(devid);
>  		nfs4_clear_ds_conn_bit(ds);
>