On Apr. 01, 2009, 7:39 +0300, "J. Bruce Fields" <bfields@xxxxxxxxxxxx> wrote:
> On Sat, Mar 28, 2009 at 11:34:41AM +0300, Benny Halevy wrote:
>> From: Andy Adamson <andros@xxxxxxxxxx>
>>
>> Implement the cb_sequence callback conforming to draft-ietf-nfsv4-minorversion1
>>
>> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
>> [Rework the back channel xdr using the shared v4.0 and v4.1 framework.]
>> Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
>> [fixed indentation]
>> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
>> ---
>> fs/nfsd/nfs4callback.c | 118 ++++++++++++++++++++++++++++++++++++++++++++
>> include/linux/nfsd/state.h | 7 ++-
>> 2 files changed, 124 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
>> index 6b7ef87..7ada6b1 100644
>> --- a/fs/nfsd/nfs4callback.c
>> +++ b/fs/nfsd/nfs4callback.c
>> @@ -255,6 +255,29 @@ encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec,
>> hdr->nops++;
>> }
>>
>> +static void
>> +encode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *args,
>> + struct nfs4_cb_compound_hdr *hdr)
>> +{
>> + __be32 *p;
>> +
>> + if (hdr->minorversion == 0)
>> + return;
>> +
>> + RESERVE_SPACE(1 + NFS4_MAX_SESSIONID_LEN + 20);
>> +
>> + WRITE32(OP_CB_SEQUENCE);
>> +#ifdef CONFIG_NFSD_V4_1
>> + WRITEMEM(args->cbs_clp->cl_sessionid.data, NFS4_MAX_SESSIONID_LEN);
>> + WRITE32(args->cbs_clp->cl_cb_seq_nr);
>> +#endif /* CONFIG_NFSD_V4_1 */
>
> This whole function should be under CONFIG_NFSD_V4_1.
>
>> + WRITE32(0); /* slotid, always 0 */
>> + WRITE32(0); /* highest slotid always 0 */
>> + WRITE32(0); /* cachethis always 0 */
>> + WRITE32(0); /* FIXME: support referring_call_lists */
>> + hdr->nops++;
>> +}
>> +
>> static int
>> nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
>> {
>> @@ -319,6 +342,69 @@ decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
>> return 0;
>> }
>>
>> +/*
>> + * Our current back channel implmentation supports a single backchannel
>> + * with a single slot.
>> + */
>> +static int
>> +decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *res,
>> + struct rpc_rqst *rqstp)
>> +{
>> + struct nfs4_callback *cb =
>> + (struct nfs4_callback *)rqstp->rq_task->tk_client->cl_private;
>> + struct nfs4_sessionid id;
>> + int status;
>> + u32 dummy;
>> + __be32 *p;
>> +
>> + if (cb->cb_minorversion == 0)
>> + return 0;
>> +
>> + status = decode_cb_op_hdr(xdr, OP_CB_SEQUENCE);
>> + if (status)
>> + return status;
>> +
>> + /*
>> + * If the server returns different values for sessionID, slotID or
>> + * sequence number, the server is looney tunes.
>> + */
>> + status = -ESERVERFAULT;
>> +
>> + READ_BUF(NFS4_MAX_SESSIONID_LEN + 16);
>> + COPYMEM(id.data, NFS4_MAX_SESSIONID_LEN);
>> +#ifdef CONFIG_NFSD_V4_1
>> + if (memcmp(id.data, res->cbs_clp->cl_sessionid.data,
>> + NFS4_MAX_SESSIONID_LEN)) {
>> + dprintk("%s Invalid session id\n", __func__);
>> + goto out;
>> + }
>> + READ32(dummy);
>> + if (dummy != res->cbs_clp->cl_cb_seq_nr) {
>> + dprintk("%s Invalid sequence number\n", __func__);
>> + goto out;
>> + }
>> +#endif /* CONFIG_NFSD_V4_1 */
>
> Ditto.
>
>> + READ32(dummy); /* slotid must be 0 */
>> + if (dummy != 0) {
>> + dprintk("%s Invalid slotid\n", __func__);
>> + goto out;
>> + }
>> + READ32(dummy); /* highest slotid must be 0 */
>> + if (dummy != 0) {
>> + dprintk("%s Invalid highest slotid\n", __func__);
>> + goto out;
>> + }
>> + READ32(dummy); /* target highest slotid must be 0 */
>> + if (dummy != 0) {
>> + dprintk("%s Invalid target highest slotid\n", __func__);
>> + goto out;
>> + }
>> + status = 0;
>> +out:
>> + return status;
>> +}
>> +
>> +
>> static int
>> nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
>> {
>> @@ -503,6 +589,38 @@ nfsd4_probe_callback(struct nfs4_client *clp)
>> return;
>> }
>>
>> +#if defined(CONFIG_NFSD_V4_1)
>> +/*
>> + * FIXME: cb_sequence should support referring call lists, cachethis, and
>> + * multiple slots
>> + */
>> +static int
>> +nfs41_cb_sequence_setup(struct nfs4_client *clp, struct nfsd4_cb_sequence *args)
>> +{
>> + u32 *ptr = (u32 *)clp->cl_sessionid.data;
>> +
>> + dprintk("%s: %u:%u:%u:%u\n", __func__,
>> + ptr[0], ptr[1], ptr[2], ptr[3]);
>> +
>> + mutex_lock(&clp->cl_cb_mutex);
>
> We shouldn't be holding a mutex across a callback. Why is this needed?
Just a simple way to limit concurrency to 1 and not deal with
multiple slots on the callback path.
Benny
>
> --b.
>
>> + args->cbs_clp = clp;
>> + clp->cl_cb_seq_nr++;
>> + return 0;
>> +}
>> +
>> +static void
>> +nfs41_cb_sequence_done(struct nfs4_client *clp, struct nfsd4_cb_sequence *res)
>> +{
>> + u32 *ptr = (u32 *)clp->cl_sessionid.data;
>> +
>> + dprintk("%s: %u:%u:%u:%u\n", __func__,
>> + ptr[0], ptr[1], ptr[2], ptr[3]);
>> +
>> + /* FIXME: support multiple callback slots */
>> + mutex_unlock(&clp->cl_cb_mutex);
>> +}
>> +#endif /* CONFIG_NFSD_V4_1 */
>> +
>> /*
>> * called with dp->dl_count inc'ed.
>> */
>> diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
>> index f2783d4..0ea8c89 100644
>> --- a/include/linux/nfsd/state.h
>> +++ b/include/linux/nfsd/state.h
>> @@ -61,6 +61,10 @@ typedef struct {
>> #define si_stateownerid si_opaque.so_stateownerid
>> #define si_fileid si_opaque.so_fileid
>>
>> +struct nfsd4_cb_sequence {
>> + /* args/res */
>> + struct nfs4_client *cbs_clp;
>> +};
>>
>> struct nfs4_cb_recall {
>> u32 cbr_ident;
>> @@ -195,7 +199,8 @@ struct nfs4_client {
>> struct nfsd4_slot cl_slot; /* create_session slot */
>> u32 cl_exchange_flags;
>> struct nfs4_sessionid cl_sessionid;
>> -
>> + /* We currently support a single back channel with a single slot */
>> + u32 cl_cb_seq_nr;
>> struct svc_xprt *cl_cb_xprt; /* 4.1 callback transport */
>> struct mutex cl_cb_mutex;
>> #endif /* CONFIG_NFSD_V4_1 */
>> --
>> 1.6.2.1
>>
--
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