On Apr. 02, 2009, 21:51 +0300, "J. Bruce Fields" <bfields@xxxxxxxxxxxx> wrote:
> On Thu, Apr 02, 2009 at 11:47:24AM +0300, Benny Halevy wrote:
>> 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.
>
> OK. We should work out some sort of asynchronous equivalent.
OK.
> How is the client side currently waiting on slots?
Currently it has a single slot and a single
(NFS41_BC_MIN_CALLBACKS) preallocated rpc_rqst.
If it gets more calls than that, concurrently, it will
drop its end of the line using
set_bit(XPRT_CLOSE_WAIT, &xprt->state)
(Ricardo, please keep me honest :)
Benny
>
> --b.
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
