Re: [PATCH 08/50] nfsv3: introduce nfs3_set_ds_client

[Tom Haynes <thomas.haynes@primarydata.com>]

On Tue, Dec 16, 2014 at 03:35:54PM -0500, Anna Schumaker wrote:
> On 12/16/2014 02:01 PM, Tom Haynes wrote:
> > From: Peng Tao <tao.peng@primarydata.com>
> > 
> > The flexfiles layout wants to create DS connection over NFSv3.
> > Add nfs3_set_ds_client to allow that to happen.
> > 
> > Signed-off-by: Peng Tao <tao.peng@primarydata.com>
> > Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>
> > ---
> >  fs/nfs/internal.h   |  7 +++++++
> >  fs/nfs/nfs3client.c | 34 ++++++++++++++++++++++++++++++++++
> >  fs/nfs/nfs3super.c  |  2 +-
> >  3 files changed, 42 insertions(+), 1 deletion(-)
> > 
> > diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> > index 7d7c36f..bf9f79f 100644
> > --- a/fs/nfs/internal.h
> > +++ b/fs/nfs/internal.h
> > @@ -193,6 +193,10 @@ extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
> >  					     rpc_authflavor_t au_flavor);
> >  extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
> >  						struct inode *);
> > +extern struct nfs_client *nfs3_set_ds_client(struct nfs_client *mds_clp,
> > +			const struct sockaddr *ds_addr, int ds_addrlen,
> > +			int ds_proto, unsigned int ds_timeo,
> > +			unsigned int ds_retrans, rpc_authflavor_t au_flavor);
> >  #ifdef CONFIG_PROC_FS
> >  extern int __init nfs_fs_proc_init(void);
> >  extern void nfs_fs_proc_exit(void);
> > @@ -381,6 +385,9 @@ extern void __exit unregister_nfs_fs(void);
> >  extern void nfs_sb_active(struct super_block *sb);
> >  extern void nfs_sb_deactive(struct super_block *sb);
> >  
> > +/* nfs3super.c */
> > +extern struct nfs_subversion nfs_v3;
> > +
> >  /* namespace.c */
> >  #define NFS_PATH_CANONICAL 1
> >  extern char *nfs_path(char **p, struct dentry *dentry,
> > diff --git a/fs/nfs/nfs3client.c b/fs/nfs/nfs3client.c
> > index 8c1b437..52e2344 100644
> > --- a/fs/nfs/nfs3client.c
> > +++ b/fs/nfs/nfs3client.c
> > @@ -64,3 +64,37 @@ struct nfs_server *nfs3_clone_server(struct nfs_server *source,
> >  		nfs_init_server_aclclient(server);
> >  	return server;
> >  }
> > +
> > +/*
> > + * Set up a pNFS Data Server client over NFSv3.
> > + *
> > + * Return any existing nfs_client that matches server address,port,version
> > + * and minorversion.
> > + *
> > + * For a new nfs_client, use a soft mount (default), a low retrans and a
> > + * low timeout interval so that if a connection is lost, we retry through
> > + * the MDS.
> > + */
> > +struct nfs_client *nfs3_set_ds_client(struct nfs_client *mds_clp,
> > +		const struct sockaddr *ds_addr, int ds_addrlen,
> > +		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
> > +		rpc_authflavor_t au_flavor)
> > +{
> > +	struct nfs_client_initdata cl_init = {
> > +		.addr = ds_addr,
> > +		.addrlen = ds_addrlen,
> > +		.nfs_mod = &nfs_v3,
> 
> Can you use get_nfs_version() / put_nfs_version() here rather than exposing nfs_v3 to the entire client?  If this *has* to be global then please put it in nfs3_fs.h.
> 
> Anna

Hi Anna,

Are you suggesting:

.nfs_mod = &get_nfs_version(3);

Does that alleviate your concern?

I guess I am asking what you mean by "exposing nfs_v3 to the entire client"?

Thanks,
Tom

> 
> > +		.proto = ds_proto,
> > +		.net = mds_clp->cl_net,
> > +	};
> > +	struct rpc_timeout ds_timeout;
> > +	struct nfs_client *clp;
> > +
> > +	/* Use the MDS nfs_client cl_ipaddr. */
> > +	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
> > +	clp = nfs_get_client(&cl_init, &ds_timeout, mds_clp->cl_ipaddr,
> > +			     au_flavor);
> > +
> > +	return clp;
> > +}
> > +EXPORT_SYMBOL_GPL(nfs3_set_ds_client);
> > diff --git a/fs/nfs/nfs3super.c b/fs/nfs/nfs3super.c
> > index 6af29c2..5c4394e 100644
> > --- a/fs/nfs/nfs3super.c
> > +++ b/fs/nfs/nfs3super.c
> > @@ -7,7 +7,7 @@
> >  #include "nfs3_fs.h"
> >  #include "nfs.h"
> >  
> > -static struct nfs_subversion nfs_v3 = {
> > +struct nfs_subversion nfs_v3 = {
> >  	.owner = THIS_MODULE,
> >  	.nfs_fs   = &nfs_fs_type,
> >  	.rpc_vers = &nfs_version3,
> > 
>