Re: [pnfs] [RFC 07/51] nfsd41: sessions basic data types

[Benny Halevy <bhalevy@panasas.com>]

On Nov. 10, 2008, 22:43 +0200, Benny Halevy <bhalevy@panasas.com> wrote:
> From: Marc Eshel <eshel@almaden.ibm.com>
> 
> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
> ---
>  fs/nfsd/nfs4state.c        |   20 ++++++++++++
>  include/linux/nfsd/state.h |   70 ++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 90 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index b91a2f1..8c1b5d9 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -310,6 +310,26 @@ static struct list_head	unconf_id_hashtbl[CLIENT_HASH_SIZE];
>  static struct list_head client_lru;
>  static struct list_head close_lru;
>  
> +#if defined(CONFIG_NFSD_V4_1)
> +static void
> +destroy_session(struct nfs41_session *ses)
> +{
> +	list_del(&ses->se_hash);
> +	list_del(&ses->se_perclnt);
> +	nfs41_put_session(ses);
> +}

rename to release_session.

> +
> +void
> +free_session(struct kref *kref)
> +{
> +	struct nfs41_session *ses;
> +
> +	ses = container_of(kref, struct nfs41_session, se_ref);
> +	kfree(ses->se_slots);
> +	kfree(ses);
> +}
> +#endif /* CONFIG_NFSD_V4_1 */
> +
>  static inline void
>  renew_client(struct nfs4_client *clp)
>  {
> diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
> index 8f492e3..2f28ad4 100644
> --- a/include/linux/nfsd/state.h
> +++ b/include/linux/nfsd/state.h
> @@ -100,6 +100,76 @@ struct nfs4_callback {
>  	struct rpc_clnt *       cb_client;
>  };
>  
> +#if defined(CONFIG_NFSD_V4_1)
> +/*
> + * nfs41_channel
> + *
> + * for both forward and back channels

review 11-12: 
channel attributes (either forward or backchannel)

> + */
> +struct nfs41_channel {

review 11-12: naming?
nfsd4_* for server names and
nfs4_ for client names

> +	u32	ch_headerpad_sz;

not used, always return zero for now.

> +	u32	ch_maxreq_sz;

we don't have to save that, just reply our max
based on svc_max_payload. ok to keep it.

> +	u32	ch_maxresp_sz;
> +	u32	ch_maxresp_cached;

we'll need at least one per-session max. variable
maybe a global max.

> +	u32	ch_maxops;

todo: nfsd_compoundargs has a max size for the preallocated ops
array. need to define that in a header file
use for both nfs4 and nfs41. (preallocated per nfsd thread)

> +	u32	ch_maxreqs;	/* number of slots */
> +};
> +
> +/* Maximum number of slots per session - XXX arbitrary */
> +#define NFS41_MAX_SLOTS 64
> +
> +/* slot states */
> +enum {
> +	NFS4_SLOT_AVAILABLE,
> +	NFS4_SLOT_INPROGRESS
> +};
> +
> +/*
> + * nfs41_slot
> + *
> + * for now, just slot sequence number - will hold DRC for this slot.
> + */
> +struct nfs41_slot {
> +	atomic_t		sl_state;

11-12: use a bitmap for the AVAIL/INPROG state.

> +	struct nfs41_session	*sl_session;

see if we can keep the pointer in the cur_sess struct

> +	u32			sl_seqid;
> +};
> +
> +/*
> + * nfs41_session
> + */
> +struct nfs41_session {
> +	struct kref		se_ref;
> +	struct list_head	se_hash;	/* hash by sessionid_t */

s/sessionid_t/sessionid/

> +	struct list_head	se_perclnt;
> +	u32			se_flags;

unused at the moment.

> +	struct nfs4_client	*se_client;	/* for expire_client */
> +	nfs41_sessionid		se_sessionid;
> +	struct nfs41_channel	se_forward;

look into whether we should embed the channel fields here
if what we use for the fore channel is different enough
from what we use for the back channel.

> +	struct nfs41_slot	*se_slots;	/* forward channel slots */
> +};
> +
> +#define se_fheaderpad_sz	se_forward.ch_headerpad_sz
> +#define se_fmaxreq_sz		se_forward.ch_maxreq_sz
> +#define se_fmaxresp_sz		se_forward.ch_maxresp_sz
> +#define se_fmaxresp_cached	se_forward.ch_maxresp_cached
> +#define se_fmaxops		se_forward.ch_maxops
> +#define se_fnumslots		se_forward.ch_maxreqs
> +
> +static inline void
> +nfs41_put_session(struct nfs41_session *ses)
> +{
> +	extern void free_session(struct kref *kref);
> +	kref_put(&ses->se_ref, free_session);
> +}
> +
> +static inline void
> +nfs41_get_session(struct nfs41_session *ses)
> +{
> +	kref_get(&ses->se_ref);
> +}
> +#endif /* CONFIG_NFSD_V4_1 */
> +
>  #define HEXDIR_LEN     33 /* hex version of 16 byte md5 of cl_name plus '\0' */
>  
>  /*