ptllnd_rx_buf.c

非常经典的一个分布式系统

        cfs_mem_cache_free(kptllnd_data.kptl_rx_cache, rx);
}

void
kptllnd_rx_buffer_callback (ptl_event_t *ev)
{
        kptl_eventarg_t        *eva = ev->md.user_ptr;
        kptl_rx_buffer_t       *rxb = kptllnd_eventarg2obj(eva);
        kptl_rx_buffer_pool_t  *rxbp = rxb->rxb_pool;
        kptl_rx_t              *rx;
        int                     unlinked;
        unsigned long           flags;

#ifdef LUSTRE_PORTALS_UNLINK_SEMANTICS
        unlinked = ev->unlinked;
#else
        unlinked = ev->type == PTL_EVENT_UNLINK;
#endif

        CDEBUG(D_NET, "%s: %s(%d) rxb=%p fail=%s(%d) unlink=%d\n",
               kptllnd_ptlid2str(ev->initiator), 
               kptllnd_evtype2str(ev->type), ev->type, rxb, 
               kptllnd_errtype2str(ev->ni_fail_type), ev->ni_fail_type,
               unlinked);

        LASSERT (!rxb->rxb_idle);
        LASSERT (ev->md.start == rxb->rxb_buffer);
        LASSERT (ev->offset + ev->mlength <= 
                 PAGE_SIZE * *kptllnd_tunables.kptl_rxb_npages);
        LASSERT (ev->type == PTL_EVENT_PUT_END || 
                 ev->type == PTL_EVENT_UNLINK);
        LASSERT (ev->type == PTL_EVENT_UNLINK ||
                 ev->match_bits == LNET_MSG_MATCHBITS);

        if (ev->ni_fail_type != PTL_NI_OK) {
                CERROR("Portals error from %s: %s(%d) rxb=%p fail=%s(%d) unlink=%dn",
                       kptllnd_ptlid2str(ev->initiator),
                       kptllnd_evtype2str(ev->type), ev->type, rxb,
                       kptllnd_errtype2str(ev->ni_fail_type),
                       ev->ni_fail_type, unlinked);

        } else if (ev->type == PTL_EVENT_PUT_END &&
                   !rxbp->rxbp_shutdown) {

                /* rxbp_shutdown sampled without locking!  I only treat it as a
                 * hint since shutdown can start while rx's are queued on
                 * kptl_sched_rxq. */
#if (PTL_MD_LOCAL_ALIGN8 == 0)
                /* Portals can't force message alignment - someone sending an
                 * odd-length message will misalign subsequent messages and
                 * force the fixup below...  */
                if ((ev->mlength & 7) != 0)
                        CWARN("Message from %s has odd length "LPU64": "
                              "probable version incompatibility\n",
                              kptllnd_ptlid2str(ev->initiator),
                              (__u64)ev->mlength);
#endif
                rx = kptllnd_rx_alloc();
                if (rx == NULL) {
                        CERROR("Message from %s dropped: ENOMEM",
                               kptllnd_ptlid2str(ev->initiator));
                } else {
                        if ((ev->offset & 7) == 0) {
                                kptllnd_rx_buffer_addref(rxb);
                                rx->rx_rxb = rxb;
                                rx->rx_nob = ev->mlength;
                                rx->rx_msg = (kptl_msg_t *)
                                             (rxb->rxb_buffer + ev->offset);
                        } else {
#if (PTL_MD_LOCAL_ALIGN8 == 0)
                                /* Portals can't force alignment - copy into
                                 * rx_space (avoiding overflow) to fix */
                                int maxlen = *kptllnd_tunables.kptl_max_msg_size;
                                
                                rx->rx_rxb = NULL;
                                rx->rx_nob = MIN(maxlen, ev->mlength);
                                rx->rx_msg = (kptl_msg_t *)rx->rx_space;
                                memcpy(rx->rx_msg, rxb->rxb_buffer + ev->offset,
                                       rx->rx_nob);
#else
                                /* Portals should have forced the alignment */
                                LBUG();
#endif
                        }

                        rx->rx_initiator = ev->initiator;
                        rx->rx_treceived = jiffies;
#ifdef CRAY_XT3
                        rx->rx_uid = ev->uid;
#endif
                        /* Queue for attention */
                        spin_lock_irqsave(&kptllnd_data.kptl_sched_lock, 
                                          flags);

                        list_add_tail(&rx->rx_list, 
                                      &kptllnd_data.kptl_sched_rxq);
                        wake_up(&kptllnd_data.kptl_sched_waitq);

                        spin_unlock_irqrestore(&kptllnd_data.kptl_sched_lock, 
                                               flags);
                }
        }

        if (unlinked) {
                spin_lock_irqsave(&rxbp->rxbp_lock, flags);

                rxb->rxb_posted = 0;
                rxb->rxb_mdh = PTL_INVALID_HANDLE;
                kptllnd_rx_buffer_decref_locked(rxb);

                spin_unlock_irqrestore(&rxbp->rxbp_lock, flags);
        }
}

void
kptllnd_nak (kptl_rx_t *rx)
{
        /* Fire-and-forget a stub message that will let the peer know my
         * protocol magic/version and make her drop/refresh any peer state she
         * might have with me. */
        ptl_md_t md = {
                .start        = kptllnd_data.kptl_nak_msg,
                .length       = kptllnd_data.kptl_nak_msg->ptlm_nob,
                .threshold    = 1,
                .options      = 0,
                .user_ptr     = NULL,
                .eq_handle    = PTL_EQ_NONE};
        ptl_handle_md_t   mdh;
        int               rc;

        rc = PtlMDBind(kptllnd_data.kptl_nih, md, PTL_UNLINK, &mdh);
        if (rc != PTL_OK) {
                CWARN("Can't NAK %s: bind failed %s(%d)\n",
                      kptllnd_ptlid2str(rx->rx_initiator),
                      kptllnd_errtype2str(rc), rc);
                return;
        }

        rc = PtlPut(mdh, PTL_NOACK_REQ, rx->rx_initiator,
                    *kptllnd_tunables.kptl_portal, 0,
                    LNET_MSG_MATCHBITS, 0, 0);

        if (rc != PTL_OK)
                CWARN("Can't NAK %s: put failed %s(%d)\n",
                      kptllnd_ptlid2str(rx->rx_initiator),
                      kptllnd_errtype2str(rc), rc);
}

void
kptllnd_rx_parse(kptl_rx_t *rx)
{
        kptl_msg_t             *msg = rx->rx_msg;
        kptl_peer_t            *peer;
        int                     rc;
        unsigned long           flags;
        lnet_process_id_t       srcid;

        LASSERT (rx->rx_peer == NULL);

        if ((rx->rx_nob >= 4 &&
             (msg->ptlm_magic == LNET_PROTO_MAGIC ||
              msg->ptlm_magic == __swab32(LNET_PROTO_MAGIC))) ||
            (rx->rx_nob >= 6 &&
             ((msg->ptlm_magic == PTLLND_MSG_MAGIC &&
               msg->ptlm_version != PTLLND_MSG_VERSION) ||
              (msg->ptlm_magic == __swab32(PTLLND_MSG_MAGIC) &&
               msg->ptlm_version != __swab16(PTLLND_MSG_VERSION))))) {
                /* NAK incompatible versions
                 * See other LNDs for how to handle this if/when ptllnd begins
                 * to allow different versions to co-exist */
                CERROR("Bad version: got %04x expected %04x from %s\n",
                       (__u32)(msg->ptlm_magic == PTLLND_MSG_MAGIC ?
                               msg->ptlm_version : __swab16(msg->ptlm_version)),
                        PTLLND_MSG_VERSION, kptllnd_ptlid2str(rx->rx_initiator));
                kptllnd_nak(rx);
                goto rx_done;
        }
        
        rc = kptllnd_msg_unpack(msg, rx->rx_nob);
        if (rc != 0) {
                CERROR ("Error %d unpacking rx from %s\n",
                        rc, kptllnd_ptlid2str(rx->rx_initiator));
                goto rx_done;
        }

        srcid.nid = msg->ptlm_srcnid;
        srcid.pid = msg->ptlm_srcpid;

        CDEBUG(D_NETTRACE, "%s: RX %s c %d %p rxb %p queued %lu ticks (%ld s)\n",
               libcfs_id2str(srcid), kptllnd_msgtype2str(msg->ptlm_type),
               msg->ptlm_credits, rx, rx->rx_rxb, 
               jiffies - rx->rx_treceived,
               cfs_duration_sec(jiffies - rx->rx_treceived));

        if (srcid.nid != kptllnd_ptl2lnetnid(rx->rx_initiator.nid)) {
                CERROR("Bad source id %s from %s\n",
                       libcfs_id2str(srcid),
                       kptllnd_ptlid2str(rx->rx_initiator));
                goto rx_done;
        }

        if (msg->ptlm_type == PTLLND_MSG_TYPE_NAK) {
                peer = kptllnd_id2peer(srcid);
                if (peer == NULL)
                        goto rx_done;
                
                CWARN("NAK from %s (%s)\n",
                      libcfs_id2str(srcid),
                      kptllnd_ptlid2str(rx->rx_initiator));

                rc = -EPROTO;
                goto failed;
        }

        if (msg->ptlm_dstnid != kptllnd_data.kptl_ni->ni_nid ||
            msg->ptlm_dstpid != the_lnet.ln_pid) {
                CERROR("Bad dstid %s (expected %s) from %s\n",
                       libcfs_id2str((lnet_process_id_t) {
                               .nid = msg->ptlm_dstnid,
                               .pid = msg->ptlm_dstpid}),
                       libcfs_id2str((lnet_process_id_t) {
                               .nid = kptllnd_data.kptl_ni->ni_nid,
                               .pid = the_lnet.ln_pid}),
                       kptllnd_ptlid2str(rx->rx_initiator));
                goto rx_done;
        }

        if (msg->ptlm_type == PTLLND_MSG_TYPE_HELLO) {
                peer = kptllnd_peer_handle_hello(rx->rx_initiator, msg);
                if (peer == NULL)
                        goto rx_done;
        } else {
                peer = kptllnd_id2peer(srcid);
                if (peer == NULL) {
                        CWARN("NAK %s: no connection; peer must reconnect\n",
                              libcfs_id2str(srcid));
                        /* NAK to make the peer reconnect */
                        kptllnd_nak(rx);
                        goto rx_done;
                }

                /* Ignore anything apart from HELLO while I'm waiting for it and
                 * any messages for a previous incarnation of the connection */
                if (peer->peer_state == PEER_STATE_WAITING_HELLO ||
                    msg->ptlm_dststamp < peer->peer_myincarnation) {
                        kptllnd_peer_decref(peer);
                        goto rx_done;
                }

                if (msg->ptlm_srcstamp != peer->peer_incarnation) {
                        CERROR("%s: Unexpected srcstamp "LPX64" "
                               "("LPX64" expected)\n",
                               libcfs_id2str(peer->peer_id),
                               msg->ptlm_srcstamp,
                               peer->peer_incarnation);
                        rc = -EPROTO;
                        goto failed;
                }

                if (msg->ptlm_dststamp != peer->peer_myincarnation) {
                        CERROR("%s: Unexpected dststamp "LPX64" "
                               "("LPX64" expected)\n",
                               libcfs_id2str(peer->peer_id), msg->ptlm_dststamp,
                               peer->peer_myincarnation);
                        rc = -EPROTO;
                        goto failed;
                }
        }

        LASSERT (msg->ptlm_srcnid == peer->peer_id.nid &&
                 msg->ptlm_srcpid == peer->peer_id.pid);

        spin_lock_irqsave(&peer->peer_lock, flags);

        /* Check peer only sends when I've sent her credits */
        if (peer->peer_sent_credits == 0) {
                int  c = peer->peer_credits;
                int oc = peer->peer_outstanding_credits;
                int sc = peer->peer_sent_credits;
                
                spin_unlock_irqrestore(&peer->peer_lock, flags);

                CERROR("%s: buffer overrun [%d/%d+%d]\n",
                       libcfs_id2str(peer->peer_id), c, sc, oc);
                goto failed;
        }
        peer->peer_sent_credits--;

        /* No check for credit overflow - the peer may post new
         * buffers after the startup handshake. */
        peer->peer_credits += msg->ptlm_credits;

        spin_unlock_irqrestore(&peer->peer_lock, flags);

        /* See if something can go out now that credits have come in */
        if (msg->ptlm_credits != 0)
                kptllnd_peer_check_sends(peer);

        /* ptllnd-level protocol correct - rx takes my ref on peer and increments
         * peer_outstanding_credits when it completes */
        rx->rx_peer = peer;
        kptllnd_peer_alive(peer);

        switch (msg->ptlm_type) {
        default:
                /* already checked by kptllnd_msg_unpack() */
                LBUG();

        case PTLLND_MSG_TYPE_HELLO:
                CDEBUG(D_NET, "PTLLND_MSG_TYPE_HELLO\n");
                goto rx_done;

        case PTLLND_MSG_TYPE_NOOP:
                CDEBUG(D_NET, "PTLLND_MSG_TYPE_NOOP\n");
                goto rx_done;

        case PTLLND_MSG_TYPE_IMMEDIATE:
                CDEBUG(D_NET, "PTLLND_MSG_TYPE_IMMEDIATE\n");
                rc = lnet_parse(kptllnd_data.kptl_ni,
                                &msg->ptlm_u.immediate.kptlim_hdr,
                                msg->ptlm_srcnid,
                                rx, 0);
                if (rc >= 0)                    /* kptllnd_recv owns 'rx' now */
                        return;
                goto failed;
                
        case PTLLND_MSG_TYPE_PUT:
        case PTLLND_MSG_TYPE_GET:
                CDEBUG(D_NET, "PTLLND_MSG_TYPE_%s\n",
                        msg->ptlm_type == PTLLND_MSG_TYPE_PUT ?
                        "PUT" : "GET");

                /* checked in kptllnd_msg_unpack() */
                LASSERT (msg->ptlm_u.rdma.kptlrm_matchbits >= 
                         PTL_RESERVED_MATCHBITS);

                /* Update last match bits seen */
                spin_lock_irqsave(&peer->peer_lock, flags);

                if (msg->ptlm_u.rdma.kptlrm_matchbits >
                    rx->rx_peer->peer_last_matchbits_seen)
                        rx->rx_peer->peer_last_matchbits_seen =
                                msg->ptlm_u.rdma.kptlrm_matchbits;

                spin_unlock_irqrestore(&rx->rx_peer->peer_lock, flags);

                rc = lnet_parse(kptllnd_data.kptl_ni,
                                &msg->ptlm_u.rdma.kptlrm_hdr,
                                msg->ptlm_srcnid,
                                rx, 1);
                if (rc >= 0)                    /* kptllnd_recv owns 'rx' now */
                        return;
                goto failed;
         }

 failed:
        kptllnd_peer_close(peer, rc);
        if (rx->rx_peer == NULL)                /* drop ref on peer */
                kptllnd_peer_decref(peer);      /* unless rx_done will */
 rx_done:
        kptllnd_rx_done(rx);
}