From 4e48761a57193279ce3f3d5170c3e38cf287b59a Mon Sep 17 00:00:00 2001 From: Amir Shehata Date: Tue, 13 Feb 2018 13:11:30 -0800 Subject: [PATCH] LU-9120 lnet: refactor lnet_select_pathway() lnet_select_pathway() is a complex monolithic function which handles many send cases. Broke down lnet_select_pathway() to multiple functions. Each function handles a different send case. This will make it easier to add the handling of the different health cases in future patches. Test-Parameters: forbuildonly Signed-off-by: Amir Shehata Change-Id: I6e554c71eaa61f3e1bdfdc60bd9cd38f70df57b5 Reviewed-on: https://review.whamcloud.com/32760 Reviewed-by: Sonia Sharma Reviewed-by: Olaf Weber Tested-by: Jenkins Reviewed-by: Chris Horn --- lnet/include/lnet/lib-lnet.h | 13 + lnet/lnet/lib-move.c | 1410 ++++++++++++++++++++++++++++-------------- 2 files changed, 944 insertions(+), 479 deletions(-) diff --git a/lnet/include/lnet/lib-lnet.h b/lnet/include/lnet/lib-lnet.h index 6197be6..f8a208d 100644 --- a/lnet/include/lnet/lib-lnet.h +++ b/lnet/include/lnet/lib-lnet.h @@ -937,6 +937,19 @@ lnet_is_peer_healthy_locked(struct lnet_peer *peer) return false; } +static inline struct lnet_peer_net * +lnet_find_peer_net_locked(struct lnet_peer *peer, __u32 net_id) +{ + struct lnet_peer_net *peer_net; + + list_for_each_entry(peer_net, &peer->lp_peer_nets, lpn_peer_nets) { + if (peer_net->lpn_net_id == net_id) + return peer_net; + } + + return NULL; +} + static inline void lnet_peer_set_alive(struct lnet_peer_ni *lp) { diff --git a/lnet/lnet/lib-move.c b/lnet/lnet/lib-move.c index e0014c2..383cc82 100644 --- a/lnet/lnet/lib-move.c +++ b/lnet/lnet/lib-move.c @@ -46,6 +46,23 @@ static int local_nid_dist_zero = 1; module_param(local_nid_dist_zero, int, 0444); MODULE_PARM_DESC(local_nid_dist_zero, "Reserved"); +struct lnet_send_data { + struct lnet_ni *sd_best_ni; + struct lnet_peer_ni *sd_best_lpni; + struct lnet_peer_ni *sd_final_dst_lpni; + struct lnet_peer *sd_peer; + struct lnet_peer *sd_gw_peer; + struct lnet_peer_ni *sd_gw_lpni; + struct lnet_peer_net *sd_peer_net; + struct lnet_msg *sd_msg; + lnet_nid_t sd_dst_nid; + lnet_nid_t sd_src_nid; + lnet_nid_t sd_rtr_nid; + int sd_cpt; + int sd_md_cpt; + __u32 sd_send_case; +}; + static inline struct lnet_comm_count * get_stats_counts(struct lnet_element_stats *stats, enum lnet_stats_type stats_type) @@ -1369,7 +1386,7 @@ lnet_compare_routes(struct lnet_route *r1, struct lnet_route *r2) } static struct lnet_peer_ni * -lnet_find_route_locked(struct lnet_net *net, lnet_nid_t target, +lnet_find_route_locked(struct lnet_net *net, __u32 remote_net, lnet_nid_t rtr_nid) { struct lnet_remotenet *rnet; @@ -1383,7 +1400,7 @@ lnet_find_route_locked(struct lnet_net *net, lnet_nid_t target, /* If @rtr_nid is not LNET_NID_ANY, return the gateway with * rtr_nid nid, otherwise find the best gateway I can use */ - rnet = lnet_find_rnet_locked(LNET_NIDNET(target)); + rnet = lnet_find_rnet_locked(remote_net); if (rnet == NULL) return NULL; @@ -1428,13 +1445,21 @@ lnet_find_route_locked(struct lnet_net *net, lnet_nid_t target, } static struct lnet_ni * -lnet_get_best_ni(struct lnet_net *local_net, struct lnet_ni *cur_ni, +lnet_get_best_ni(struct lnet_net *local_net, struct lnet_ni *best_ni, + struct lnet_peer *peer, struct lnet_peer_net *peer_net, int md_cpt) { - struct lnet_ni *ni = NULL, *best_ni = cur_ni; + struct lnet_ni *ni = NULL; unsigned int shortest_distance; int best_credits; + /* + * If there is no peer_ni that we can send to on this network, + * then there is no point in looking for a new best_ni here. + */ + if (!lnet_get_next_peer_ni_locked(peer, peer_net, NULL)) + return best_ni; + if (best_ni == NULL) { shortest_distance = UINT_MAX; best_credits = INT_MIN; @@ -1462,6 +1487,12 @@ lnet_get_best_ni(struct lnet_net *local_net, struct lnet_ni *cur_ni, md_cpt, ni->ni_dev_cpt); + CDEBUG(D_NET, "compare ni %s [c:%d, d:%d, s:%d] with best_ni %s [c:%d, d:%d, s:%d]\n", + libcfs_nid2str(ni->ni_nid), ni_credits, distance, + ni->ni_seq, (best_ni) ? libcfs_nid2str(best_ni->ni_nid) + : "not seleced", best_credits, shortest_distance, + (best_ni) ? best_ni->ni_seq : 0); + /* * All distances smaller than the NUMA range * are treated equally. @@ -1487,6 +1518,9 @@ lnet_get_best_ni(struct lnet_net *local_net, struct lnet_ni *cur_ni, best_credits = ni_credits; } + CDEBUG(D_NET, "selected best_ni %s\n", + (best_ni) ? libcfs_nid2str(best_ni->ni_nid) : "no selection"); + return best_ni; } @@ -1511,422 +1545,150 @@ lnet_msg_discovery(struct lnet_msg *msg) return false; } +#define SRC_SPEC 0x0001 +#define SRC_ANY 0x0002 +#define LOCAL_DST 0x0004 +#define REMOTE_DST 0x0008 +#define MR_DST 0x0010 +#define NMR_DST 0x0020 +#define SND_RESP 0x0040 + +/* The following to defines are used for return codes */ +#define REPEAT_SEND 0x1000 +#define PASS_THROUGH 0x2000 + +/* The different cases lnet_select pathway needs to handle */ +#define SRC_SPEC_LOCAL_MR_DST (SRC_SPEC | LOCAL_DST | MR_DST) +#define SRC_SPEC_ROUTER_MR_DST (SRC_SPEC | REMOTE_DST | MR_DST) +#define SRC_SPEC_LOCAL_NMR_DST (SRC_SPEC | LOCAL_DST | NMR_DST) +#define SRC_SPEC_ROUTER_NMR_DST (SRC_SPEC | REMOTE_DST | NMR_DST) +#define SRC_ANY_LOCAL_MR_DST (SRC_ANY | LOCAL_DST | MR_DST) +#define SRC_ANY_ROUTER_MR_DST (SRC_ANY | REMOTE_DST | MR_DST) +#define SRC_ANY_LOCAL_NMR_DST (SRC_ANY | LOCAL_DST | NMR_DST) +#define SRC_ANY_ROUTER_NMR_DST (SRC_ANY | REMOTE_DST | NMR_DST) + static int -lnet_select_pathway(lnet_nid_t src_nid, lnet_nid_t dst_nid, - struct lnet_msg *msg, lnet_nid_t rtr_nid) +lnet_handle_send(struct lnet_send_data *sd) { - struct lnet_ni *best_ni; - struct lnet_peer_ni *best_lpni; - struct lnet_peer_ni *best_gw; - struct lnet_peer_ni *lpni; - struct lnet_peer_ni *final_dst; - struct lnet_peer *peer; - struct lnet_peer_net *peer_net; - struct lnet_net *local_net; - int cpt, cpt2, rc; - bool routing; - bool routing2; - bool ni_is_pref; - bool preferred; - bool local_found; - int best_lpni_credits; - int md_cpt; - - /* - * get an initial CPT to use for locking. The idea here is not to - * serialize the calls to select_pathway, so that as many - * operations can run concurrently as possible. To do that we use - * the CPT where this call is being executed. Later on when we - * determine the CPT to use in lnet_message_commit, we switch the - * lock and check if there was any configuration change. If none, - * then we proceed, if there is, then we restart the operation. - */ - cpt = lnet_net_lock_current(); - - md_cpt = lnet_cpt_of_md(msg->msg_md, msg->msg_offset); - if (md_cpt == CFS_CPT_ANY) - md_cpt = cpt; - -again: - best_ni = NULL; - best_lpni = NULL; - best_gw = NULL; - final_dst = NULL; - local_net = NULL; - routing = false; - routing2 = false; - local_found = false; + struct lnet_ni *best_ni = sd->sd_best_ni; + struct lnet_peer_ni *best_lpni = sd->sd_best_lpni; + struct lnet_peer_ni *final_dst_lpni = sd->sd_final_dst_lpni; + struct lnet_msg *msg = sd->sd_msg; + int cpt2; + __u32 send_case = sd->sd_send_case; + int rc; + __u32 routing = send_case & REMOTE_DST; /* - * lnet_nid2peerni_locked() is the path that will find an - * existing peer_ni, or create one and mark it as having been - * created due to network traffic. + * Increment sequence number of the selected peer so that we + * pick the next one in Round Robin. */ - lpni = lnet_nid2peerni_locked(dst_nid, LNET_NID_ANY, cpt); - if (IS_ERR(lpni)) { - lnet_net_unlock(cpt); - return PTR_ERR(lpni); - } + best_lpni->lpni_seq++; /* - * If we're being asked to send to the loopback interface, there - * is no need to go through any selection. We can just shortcut - * the entire process and send over lolnd + * grab a reference on the peer_ni so it sticks around even if + * we need to drop and relock the lnet_net_lock below. */ - if (LNET_NETTYP(LNET_NIDNET(dst_nid)) == LOLND) { - lnet_peer_ni_decref_locked(lpni); - best_ni = the_lnet.ln_loni; - goto send; - } + lnet_peer_ni_addref_locked(best_lpni); /* - * Now that we have a peer_ni, check if we want to discover - * the peer. Traffic to the LNET_RESERVED_PORTAL should not - * trigger discovery. + * Use lnet_cpt_of_nid() to determine the CPT used to commit the + * message. This ensures that we get a CPT that is correct for + * the NI when the NI has been restricted to a subset of all CPTs. + * If the selected CPT differs from the one currently locked, we + * must unlock and relock the lnet_net_lock(), and then check whether + * the configuration has changed. We don't have a hold on the best_ni + * yet, and it may have vanished. */ - peer = lpni->lpni_peer_net->lpn_peer; - if (lnet_msg_discovery(msg) && !lnet_peer_is_uptodate(peer)) { - rc = lnet_discover_peer_locked(lpni, cpt, false); - if (rc) { - lnet_peer_ni_decref_locked(lpni); - lnet_net_unlock(cpt); - return rc; + cpt2 = lnet_cpt_of_nid_locked(best_lpni->lpni_nid, best_ni); + if (sd->sd_cpt != cpt2) { + __u32 seq = lnet_get_dlc_seq_locked(); + lnet_net_unlock(sd->sd_cpt); + sd->sd_cpt = cpt2; + lnet_net_lock(sd->sd_cpt); + if (seq != lnet_get_dlc_seq_locked()) { + lnet_peer_ni_decref_locked(best_lpni); + return REPEAT_SEND; } - /* The peer may have changed. */ - peer = lpni->lpni_peer_net->lpn_peer; - /* queue message and return */ - msg->msg_src_nid_param = src_nid; - msg->msg_rtr_nid_param = rtr_nid; - msg->msg_sending = 0; - list_add_tail(&msg->msg_list, &peer->lp_dc_pendq); - CDEBUG(D_NET, "%s pending discovery\n", - libcfs_nid2str(peer->lp_primary_nid)); - lnet_peer_ni_decref_locked(lpni); - lnet_net_unlock(cpt); - - return LNET_DC_WAIT; - } - lnet_peer_ni_decref_locked(lpni); - - /* If peer is not healthy then can not send anything to it */ - if (!lnet_is_peer_healthy_locked(peer)) { - lnet_net_unlock(cpt); - return -EHOSTUNREACH; } /* - * STEP 1: first jab at determining best_ni - * if src_nid is explicitly specified, then best_ni is already - * pre-determiend for us. Otherwise we need to select the best - * one to use later on + * store the best_lpni in the message right away to avoid having + * to do the same operation under different conditions */ - if (src_nid != LNET_NID_ANY) { - best_ni = lnet_nid2ni_locked(src_nid, cpt); - if (!best_ni) { - lnet_net_unlock(cpt); - LCONSOLE_WARN("Can't send to %s: src %s is not a " - "local nid\n", libcfs_nid2str(dst_nid), - libcfs_nid2str(src_nid)); - return -EINVAL; - } - } - - if (msg->msg_type == LNET_MSG_REPLY || - msg->msg_type == LNET_MSG_ACK || - !lnet_peer_is_multi_rail(peer) || - best_ni) { - /* - * for replies we want to respond on the same peer_ni we - * received the message on if possible. If not, then pick - * a peer_ni to send to - * - * if the peer is non-multi-rail then you want to send to - * the dst_nid provided as well. - * - * If the best_ni has already been determined, IE the - * src_nid has been specified, then use the - * destination_nid provided as well, since we're - * continuing a series of related messages for the same - * RPC. - * - * It is expected to find the lpni using dst_nid, since we - * created it earlier. - */ - best_lpni = lnet_find_peer_ni_locked(dst_nid); - if (best_lpni) - lnet_peer_ni_decref_locked(best_lpni); - - if (best_lpni && !lnet_get_net_locked(LNET_NIDNET(dst_nid))) { - /* - * this lpni is not on a local network so we need - * to route this reply. - */ - best_gw = lnet_find_route_locked(NULL, - best_lpni->lpni_nid, - rtr_nid); - if (best_gw) { - /* - * RULE: Each node considers only the next-hop - * - * We're going to route the message, so change the peer to - * the router. - */ - LASSERT(best_gw->lpni_peer_net); - LASSERT(best_gw->lpni_peer_net->lpn_peer); - peer = best_gw->lpni_peer_net->lpn_peer; - - /* - * if the router is not multi-rail then use the best_gw - * found to send the message to - */ - if (!lnet_peer_is_multi_rail(peer)) - best_lpni = best_gw; - else - best_lpni = NULL; - - routing = true; - } else { - best_lpni = NULL; - } - } else if (!best_lpni) { - lnet_net_unlock(cpt); - CERROR("unable to send msg_type %d to " - "originating %s. Destination NID not in DB\n", - msg->msg_type, libcfs_nid2str(dst_nid)); - return -EINVAL; - } - } + msg->msg_txpeer = best_lpni; + msg->msg_txni = best_ni; /* - * We must use a consistent source address when sending to a - * non-MR peer. However, a non-MR peer can have multiple NIDs - * on multiple networks, and we may even need to talk to this - * peer on multiple networks -- certain types of - * load-balancing configuration do this. - * - * So we need to pick the NI the peer prefers for this - * particular network. + * grab a reference for the best_ni since now it's in use in this + * send. The reference will be dropped in lnet_finalize() */ - if (!lnet_peer_is_multi_rail(peer)) { - if (!best_lpni) { - lnet_net_unlock(cpt); - CERROR("no route to %s\n", - libcfs_nid2str(dst_nid)); - return -EHOSTUNREACH; - } - - /* best ni is already set if src_nid was provided */ - if (!best_ni) { - /* Get the target peer_ni */ - peer_net = lnet_peer_get_net_locked(peer, - LNET_NIDNET(best_lpni->lpni_nid)); - LASSERT(peer_net != NULL); - list_for_each_entry(lpni, &peer_net->lpn_peer_nis, - lpni_peer_nis) { - if (lpni->lpni_pref_nnids == 0) - continue; - LASSERT(lpni->lpni_pref_nnids == 1); - best_ni = lnet_nid2ni_locked( - lpni->lpni_pref.nid, cpt); - break; - } - } - /* if best_ni is still not set just pick one */ - if (!best_ni) { - best_ni = lnet_net2ni_locked( - best_lpni->lpni_net->net_id, cpt); - /* If there is no best_ni we don't have a route */ - if (!best_ni) { - CERROR("no path to %s from net %s\n", - libcfs_nid2str(best_lpni->lpni_nid), - libcfs_net2str(best_lpni->lpni_net->net_id)); - lnet_net_unlock(cpt); - return -EHOSTUNREACH; - } - lpni = list_entry(peer_net->lpn_peer_nis.next, - struct lnet_peer_ni, - lpni_peer_nis); - } - /* Set preferred NI if necessary. */ - if (lpni->lpni_pref_nnids == 0) - lnet_peer_ni_set_non_mr_pref_nid(lpni, best_ni->ni_nid); - } + lnet_ni_addref_locked(msg->msg_txni, sd->sd_cpt); /* - * if we already found a best_ni because src_nid is specified and - * best_lpni because we are replying to a message then just send - * the message + * Always set the target.nid to the best peer picked. Either the + * NID will be one of the peer NIDs selected, or the same NID as + * what was originally set in the target or it will be the NID of + * a router if this message should be routed */ - if (best_ni && best_lpni) - goto send; + msg->msg_target.nid = msg->msg_txpeer->lpni_nid; /* - * If we already found a best_ni because src_nid is specified then - * pick the peer then send the message + * lnet_msg_commit assigns the correct cpt to the message, which + * is used to decrement the correct refcount on the ni when it's + * time to return the credits */ - if (best_ni) - goto pick_peer; + lnet_msg_commit(msg, sd->sd_cpt); /* - * pick the best_ni by going through all the possible networks of - * that peer and see which local NI is best suited to talk to that - * peer. - * - * Locally connected networks will always be preferred over - * a routed network. If there are only routed paths to the peer, - * then the best route is chosen. If all routes are equal then - * they are used in round robin. + * If we are routing the message then we keep the src_nid that was + * set by the originator. If we are not routing then we are the + * originator and set it here. */ - list_for_each_entry(peer_net, &peer->lp_peer_nets, lpn_peer_nets) { - if (!lnet_is_peer_net_healthy_locked(peer_net)) - continue; - - local_net = lnet_get_net_locked(peer_net->lpn_net_id); - if (!local_net && !routing && !local_found) { - struct lnet_peer_ni *net_gw; - - lpni = list_entry(peer_net->lpn_peer_nis.next, - struct lnet_peer_ni, - lpni_peer_nis); - - net_gw = lnet_find_route_locked(NULL, - lpni->lpni_nid, - rtr_nid); - if (!net_gw) - continue; - - if (best_gw) { - /* - * lnet_find_route_locked() call - * will return the best_Gw on the - * lpni->lpni_nid network. - * However, best_gw and net_gw can - * be on different networks. - * Therefore need to compare them - * to pick the better of either. - */ - if (lnet_compare_peers(best_gw, net_gw) > 0) - continue; - if (best_gw->lpni_gw_seq <= net_gw->lpni_gw_seq) - continue; - } - best_gw = net_gw; - final_dst = lpni; - - routing2 = true; - } else { - best_gw = NULL; - final_dst = NULL; - routing2 = false; - local_found = true; - } - - /* - * a gw on this network is found, but there could be - * other better gateways on other networks. So don't pick - * the best_ni until we determine the best_gw. - */ - if (best_gw) - continue; - - /* if no local_net found continue */ - if (!local_net) - continue; + if (!msg->msg_routing) + msg->msg_hdr.src_nid = cpu_to_le64(msg->msg_txni->ni_nid); + if (routing) { + msg->msg_target_is_router = 1; + msg->msg_target.pid = LNET_PID_LUSTRE; /* - * Iterate through the NIs in this local Net and select - * the NI to send from. The selection is determined by - * these 3 criterion in the following priority: - * 1. NUMA - * 2. NI available credits - * 3. Round Robin + * since we're routing we want to ensure that the + * msg_hdr.dest_nid is set to the final destination. When + * the router receives this message it knows how to route + * it. + * + * final_dst_lpni is set at the beginning of the + * lnet_select_pathway() function and is never changed. + * It's safe to use it here. */ - best_ni = lnet_get_best_ni(local_net, best_ni, md_cpt); - } - - if (!best_ni && !best_gw) { - lnet_net_unlock(cpt); - LCONSOLE_WARN("No local ni found to send from to %s\n", - libcfs_nid2str(dst_nid)); - return -EINVAL; - } - - if (!best_ni) { - best_ni = lnet_get_best_ni(best_gw->lpni_net, best_ni, md_cpt); - LASSERT(best_gw && best_ni); - + msg->msg_hdr.dest_nid = cpu_to_le64(final_dst_lpni->lpni_nid); + } else { /* - * We're going to route the message, so change the peer to - * the router. + * if we're not routing set the dest_nid to the best peer + * ni NID that we picked earlier in the algorithm. */ - LASSERT(best_gw->lpni_peer_net); - LASSERT(best_gw->lpni_peer_net->lpn_peer); - best_gw->lpni_gw_seq++; - peer = best_gw->lpni_peer_net->lpn_peer; + msg->msg_hdr.dest_nid = cpu_to_le64(msg->msg_txpeer->lpni_nid); } - /* - * Now that we selected the NI to use increment its sequence - * number so the Round Robin algorithm will detect that it has - * been used and pick the next NI. - */ - best_ni->ni_seq++; - -pick_peer: - /* - * At this point the best_ni is on a local network on which - * the peer has a peer_ni as well - */ - peer_net = lnet_peer_get_net_locked(peer, - best_ni->ni_net->net_id); - /* - * peer_net is not available or the src_nid is explicitly defined - * and the peer_net for that src_nid is unhealthy. find a route to - * the destination nid. - */ - if (!peer_net || - (src_nid != LNET_NID_ANY && - !lnet_is_peer_net_healthy_locked(peer_net))) { - best_gw = lnet_find_route_locked(best_ni->ni_net, - dst_nid, - rtr_nid); - /* - * if no route is found for that network then - * move onto the next peer_ni in the peer - */ - if (!best_gw) { - LCONSOLE_WARN("No route to peer from %s\n", - libcfs_nid2str(best_ni->ni_nid)); - lnet_net_unlock(cpt); - return -EHOSTUNREACH; - } + rc = lnet_post_send_locked(msg, 0); - CDEBUG(D_NET, "Best route to %s via %s for %s %d\n", - libcfs_nid2str(dst_nid), - libcfs_nid2str(best_gw->lpni_nid), - lnet_msgtyp2str(msg->msg_type), msg->msg_len); + if (!rc) + CDEBUG(D_NET, "TRACE: %s(%s:%s) -> %s(%s:%s) : %s\n", + libcfs_nid2str(msg->msg_hdr.src_nid), + libcfs_nid2str(msg->msg_txni->ni_nid), + libcfs_nid2str(sd->sd_src_nid), + libcfs_nid2str(msg->msg_hdr.dest_nid), + libcfs_nid2str(sd->sd_dst_nid), + libcfs_nid2str(msg->msg_txpeer->lpni_nid), + lnet_msgtyp2str(msg->msg_type)); - routing2 = true; - /* - * RULE: Each node considers only the next-hop - * - * We're going to route the message, so change the peer to - * the router. - */ - LASSERT(best_gw->lpni_peer_net); - LASSERT(best_gw->lpni_peer_net->lpn_peer); - peer = best_gw->lpni_peer_net->lpn_peer; - } else if (!lnet_is_peer_net_healthy_locked(peer_net)) { - /* - * this peer_net is unhealthy but we still have an opportunity - * to find another peer_net that we can use - */ - __u32 net_id = peer_net->lpn_net_id; - LCONSOLE_WARN("peer net %s unhealthy\n", - libcfs_net2str(net_id)); - goto again; - } + return rc; +} +static struct lnet_peer_ni * +lnet_select_peer_ni(struct lnet_send_data *sd, struct lnet_peer *peer, + struct lnet_peer_net *peer_net) +{ /* * Look at the peer NIs for the destination peer that connect * to the chosen net. If a peer_ni is preferred when using the @@ -1935,20 +1697,31 @@ pick_peer: * the available transmit credits are used. If the transmit * credits are equal, we round-robin over the peer_ni. */ - lpni = NULL; - best_lpni_credits = INT_MIN; - preferred = false; - best_lpni = NULL; + struct lnet_peer_ni *lpni = NULL; + struct lnet_peer_ni *best_lpni = NULL; + struct lnet_ni *best_ni = sd->sd_best_ni; + lnet_nid_t dst_nid = sd->sd_dst_nid; + int best_lpni_credits = INT_MIN; + bool preferred = false; + bool ni_is_pref; + while ((lpni = lnet_get_next_peer_ni_locked(peer, peer_net, lpni))) { /* - * if this peer ni is not healthy just skip it, no point in - * examining it further + * if the best_ni we've chosen aleady has this lpni + * preferred, then let's use it */ - if (!lnet_is_peer_ni_healthy_locked(lpni)) - continue; ni_is_pref = lnet_peer_is_pref_nid_locked(lpni, best_ni->ni_nid); + CDEBUG(D_NET, "%s ni_is_pref = %d\n", + libcfs_nid2str(best_ni->ni_nid), ni_is_pref); + + if (best_lpni) + CDEBUG(D_NET, "%s c:[%d, %d], s:[%d, %d]\n", + libcfs_nid2str(lpni->lpni_nid), + lpni->lpni_txcredits, best_lpni_credits, + lpni->lpni_seq, best_lpni->lpni_seq); + /* if this is a preferred peer use it */ if (!preferred && ni_is_pref) { preferred = true; @@ -1986,133 +1759,812 @@ pick_peer: if (!best_lpni) { __u32 net_id = (peer_net) ? peer_net->lpn_net_id : LNET_NIDNET(dst_nid); - lnet_net_unlock(cpt); - LCONSOLE_WARN("no peer_ni found on peer net %s\n", + CDEBUG(D_NET, "no peer_ni found on peer net %s\n", libcfs_net2str(net_id)); - return -EHOSTUNREACH; + return NULL; } + CDEBUG(D_NET, "sd_best_lpni = %s\n", + libcfs_nid2str(best_lpni->lpni_nid)); -send: - /* Shortcut for loopback. */ - if (best_ni == the_lnet.ln_loni) { - /* No send credit hassles with LOLND */ - lnet_ni_addref_locked(best_ni, cpt); - msg->msg_hdr.dest_nid = cpu_to_le64(best_ni->ni_nid); - if (!msg->msg_routing) - msg->msg_hdr.src_nid = cpu_to_le64(best_ni->ni_nid); - msg->msg_target.nid = best_ni->ni_nid; - lnet_msg_commit(msg, cpt); - msg->msg_txni = best_ni; - lnet_net_unlock(cpt); - - return LNET_CREDIT_OK; - } + return best_lpni; +} - routing = routing || routing2; +/* + * Prerequisite: the best_ni should already be set in the sd + */ +static inline struct lnet_peer_ni * +lnet_find_best_lpni_on_net(struct lnet_send_data *sd, struct lnet_peer *peer, + __u32 net_id) +{ + struct lnet_peer_net *peer_net; /* - * Increment sequence number of the peer selected so that we - * pick the next one in Round Robin. + * The gateway is Multi-Rail capable so now we must select the + * proper peer_ni */ - best_lpni->lpni_seq++; + peer_net = lnet_peer_get_net_locked(peer, net_id); + + if (!peer_net) { + CERROR("gateway peer %s has no NI on net %s\n", + libcfs_nid2str(peer->lp_primary_nid), + libcfs_net2str(net_id)); + return NULL; + } + + return lnet_select_peer_ni(sd, peer, peer_net); +} + +static inline void +lnet_set_non_mr_pref_nid(struct lnet_send_data *sd) +{ + if (sd->sd_send_case & NMR_DST && + sd->sd_msg->msg_type != LNET_MSG_REPLY && + sd->sd_msg->msg_type != LNET_MSG_ACK && + sd->sd_best_lpni->lpni_pref_nnids == 0) { + CDEBUG(D_NET, "Setting preferred local NID %s on NMR peer %s\n", + libcfs_nid2str(sd->sd_best_ni->ni_nid), + libcfs_nid2str(sd->sd_best_lpni->lpni_nid)); + lnet_peer_ni_set_non_mr_pref_nid(sd->sd_best_lpni, + sd->sd_best_ni->ni_nid); + } +} + +/* + * Source Specified + * Local Destination + * non-mr peer + * + * use the source and destination NIDs as the pathway + */ +static int +lnet_handle_spec_local_nmr_dst(struct lnet_send_data *sd) +{ + /* the destination lpni is set before we get here. */ + + /* find local NI */ + sd->sd_best_ni = lnet_nid2ni_locked(sd->sd_src_nid, sd->sd_cpt); + if (!sd->sd_best_ni) { + CERROR("Can't send to %s: src %s is not a " + "local nid\n", libcfs_nid2str(sd->sd_dst_nid), + libcfs_nid2str(sd->sd_src_nid)); + return -EINVAL; + } /* - * grab a reference on the peer_ni so it sticks around even if - * we need to drop and relock the lnet_net_lock below. + * the preferred NID will only be set for NMR peers */ - lnet_peer_ni_addref_locked(best_lpni); + lnet_set_non_mr_pref_nid(sd); + + return lnet_handle_send(sd); +} + +/* + * Source Specified + * Local Destination + * MR Peer + * + * Run the selection algorithm on the peer NIs unless we're sending + * a response, in this case just send to the destination + */ +static int +lnet_handle_spec_local_mr_dst(struct lnet_send_data *sd) +{ + sd->sd_best_ni = lnet_nid2ni_locked(sd->sd_src_nid, sd->sd_cpt); + if (!sd->sd_best_ni) { + CERROR("Can't send to %s: src %s is not a " + "local nid\n", libcfs_nid2str(sd->sd_dst_nid), + libcfs_nid2str(sd->sd_src_nid)); + return -EINVAL; + } /* - * Use lnet_cpt_of_nid() to determine the CPT used to commit the - * message. This ensures that we get a CPT that is correct for - * the NI when the NI has been restricted to a subset of all CPTs. - * If the selected CPT differs from the one currently locked, we - * must unlock and relock the lnet_net_lock(), and then check whether - * the configuration has changed. We don't have a hold on the best_ni - * yet, and it may have vanished. + * only run the selection algorithm to pick the peer_ni if we're + * sending a GET or a PUT. Responses are sent to the same + * destination NID provided. */ - cpt2 = lnet_cpt_of_nid_locked(best_lpni->lpni_nid, best_ni); - if (cpt != cpt2) { - __u32 seq = lnet_get_dlc_seq_locked(); - lnet_net_unlock(cpt); - cpt = cpt2; - lnet_net_lock(cpt); - if (seq != lnet_get_dlc_seq_locked()) { - lnet_peer_ni_decref_locked(best_lpni); - goto again; + if (!(sd->sd_send_case & SND_RESP)) { + sd->sd_best_lpni = + lnet_find_best_lpni_on_net(sd, sd->sd_peer, + sd->sd_best_ni->ni_net->net_id); + } + + if (sd->sd_best_lpni) + return lnet_handle_send(sd); + + CERROR("can't send to %s. no NI on %s\n", + libcfs_nid2str(sd->sd_dst_nid), + libcfs_net2str(sd->sd_best_ni->ni_net->net_id)); + + return -EHOSTUNREACH; +} + +struct lnet_ni * +lnet_find_best_ni_on_spec_net(struct lnet_ni *cur_best_ni, + struct lnet_peer *peer, + struct lnet_peer_net *peer_net, + int cpt, + bool incr_seq) +{ + struct lnet_net *local_net; + struct lnet_ni *best_ni; + + local_net = lnet_get_net_locked(peer_net->lpn_net_id); + if (!local_net) + return NULL; + + /* + * Iterate through the NIs in this local Net and select + * the NI to send from. The selection is determined by + * these 3 criterion in the following priority: + * 1. NUMA + * 2. NI available credits + * 3. Round Robin + */ + best_ni = lnet_get_best_ni(local_net, cur_best_ni, + peer, peer_net, cpt); + + if (incr_seq && best_ni) + best_ni->ni_seq++; + + return best_ni; +} + +static int +lnet_handle_find_routed_path(struct lnet_send_data *sd, + lnet_nid_t dst_nid, + struct lnet_peer_ni **gw_lpni, + struct lnet_peer **gw_peer) +{ + struct lnet_peer_ni *gw; + lnet_nid_t src_nid = sd->sd_src_nid; + + gw = lnet_find_route_locked(NULL, LNET_NIDNET(dst_nid), + sd->sd_rtr_nid); + if (!gw) { + CERROR("no route to %s from %s\n", + libcfs_nid2str(dst_nid), libcfs_nid2str(src_nid)); + return -EHOSTUNREACH; + } + + /* get the peer of the gw_ni */ + LASSERT(gw->lpni_peer_net); + LASSERT(gw->lpni_peer_net->lpn_peer); + + *gw_peer = gw->lpni_peer_net->lpn_peer; + + if (!sd->sd_best_ni) + sd->sd_best_ni = lnet_find_best_ni_on_spec_net(NULL, *gw_peer, + gw->lpni_peer_net, + sd->sd_md_cpt, + true); + + if (!sd->sd_best_ni) { + CERROR("Internal Error. Expected local ni on %s " + "but non found :%s\n", + libcfs_net2str(gw->lpni_peer_net->lpn_net_id), + libcfs_nid2str(sd->sd_src_nid)); + return -EFAULT; + } + + /* + * if gw is MR let's find its best peer_ni + */ + if (lnet_peer_is_multi_rail(*gw_peer)) { + gw = lnet_find_best_lpni_on_net(sd, *gw_peer, + sd->sd_best_ni->ni_net->net_id); + /* + * We've already verified that the gw has an NI on that + * desired net, but we're not finding it. Something is + * wrong. + */ + if (!gw) { + CERROR("Internal Error. Route expected to %s from %s\n", + libcfs_nid2str(dst_nid), + libcfs_nid2str(src_nid)); + return -EFAULT; } } + *gw_lpni = gw; + + return 0; +} + +/* + * Handle two cases: + * + * Case 1: + * Source specified + * Remote destination + * Non-MR destination + * + * Case 2: + * Source specified + * Remote destination + * MR destination + * + * The handling of these two cases is similar. Even though the destination + * can be MR or non-MR, we'll deal directly with the router. + */ +static int +lnet_handle_spec_router_dst(struct lnet_send_data *sd) +{ + int rc; + struct lnet_peer_ni *gw_lpni = NULL; + struct lnet_peer *gw_peer = NULL; + + /* find local NI */ + sd->sd_best_ni = lnet_nid2ni_locked(sd->sd_src_nid, sd->sd_cpt); + if (!sd->sd_best_ni) { + CERROR("Can't send to %s: src %s is not a " + "local nid\n", libcfs_nid2str(sd->sd_dst_nid), + libcfs_nid2str(sd->sd_src_nid)); + return -EINVAL; + } + + rc = lnet_handle_find_routed_path(sd, sd->sd_dst_nid, &gw_lpni, + &gw_peer); + if (rc < 0) + return rc; + + if (sd->sd_send_case & NMR_DST) + /* + * since the final destination is non-MR let's set its preferred + * NID before we send + */ + lnet_set_non_mr_pref_nid(sd); + /* - * store the best_lpni in the message right away to avoid having - * to do the same operation under different conditions + * We're going to send to the gw found so let's set its + * info */ - msg->msg_txpeer = best_lpni; - msg->msg_txni = best_ni; + sd->sd_peer = gw_peer; + sd->sd_best_lpni = gw_lpni; + + return lnet_handle_send(sd); +} + +struct lnet_ni * +lnet_find_best_ni_on_local_net(struct lnet_peer *peer, int md_cpt) +{ + struct lnet_peer_net *peer_net = NULL; + struct lnet_ni *best_ni = NULL; /* - * grab a reference for the best_ni since now it's in use in this - * send. the reference will need to be dropped when the message is - * finished in lnet_finalize() + * The peer can have multiple interfaces, some of them can be on + * the local network and others on a routed network. We should + * prefer the local network. However if the local network is not + * available then we need to try the routed network + */ + + /* go through all the peer nets and find the best_ni */ + list_for_each_entry(peer_net, &peer->lp_peer_nets, lpn_peer_nets) { + /* + * The peer's list of nets can contain non-local nets. We + * want to only examine the local ones. + */ + if (!lnet_get_net_locked(peer_net->lpn_net_id)) + continue; + best_ni = lnet_find_best_ni_on_spec_net(best_ni, peer, + peer_net, md_cpt, false); + } + + if (best_ni) + /* increment sequence number so we can round robin */ + best_ni->ni_seq++; + + return best_ni; +} + +static struct lnet_ni * +lnet_find_existing_preferred_best_ni(struct lnet_send_data *sd) +{ + struct lnet_ni *best_ni = NULL; + struct lnet_peer_net *peer_net; + struct lnet_peer *peer = sd->sd_peer; + struct lnet_peer_ni *best_lpni = sd->sd_best_lpni; + struct lnet_peer_ni *lpni; + int cpt = sd->sd_cpt; + + /* + * We must use a consistent source address when sending to a + * non-MR peer. However, a non-MR peer can have multiple NIDs + * on multiple networks, and we may even need to talk to this + * peer on multiple networks -- certain types of + * load-balancing configuration do this. + * + * So we need to pick the NI the peer prefers for this + * particular network. */ - lnet_ni_addref_locked(msg->msg_txni, cpt); + + /* Get the target peer_ni */ + peer_net = lnet_peer_get_net_locked(peer, + LNET_NIDNET(best_lpni->lpni_nid)); + LASSERT(peer_net != NULL); + list_for_each_entry(lpni, &peer_net->lpn_peer_nis, + lpni_peer_nis) { + if (lpni->lpni_pref_nnids == 0) + continue; + LASSERT(lpni->lpni_pref_nnids == 1); + best_ni = lnet_nid2ni_locked( + lpni->lpni_pref.nid, cpt); + break; + } + + return best_ni; +} + +/* Prerequisite: sd->sd_peer and sd->sd_best_lpni should be set */ +static int +lnet_select_preferred_best_ni(struct lnet_send_data *sd) +{ + struct lnet_ni *best_ni = NULL; + struct lnet_peer_ni *best_lpni = sd->sd_best_lpni; /* - * Always set the target.nid to the best peer picked. Either the - * nid will be one of the preconfigured NIDs, or the same NID as - * what was originally set in the target or it will be the NID of - * a router if this message should be routed + * We must use a consistent source address when sending to a + * non-MR peer. However, a non-MR peer can have multiple NIDs + * on multiple networks, and we may even need to talk to this + * peer on multiple networks -- certain types of + * load-balancing configuration do this. + * + * So we need to pick the NI the peer prefers for this + * particular network. */ - msg->msg_target.nid = msg->msg_txpeer->lpni_nid; + + best_ni = lnet_find_existing_preferred_best_ni(sd); + + /* if best_ni is still not set just pick one */ + if (!best_ni) { + best_ni = + lnet_find_best_ni_on_spec_net(NULL, sd->sd_peer, + sd->sd_best_lpni->lpni_peer_net, + sd->sd_md_cpt, true); + /* If there is no best_ni we don't have a route */ + if (!best_ni) { + CERROR("no path to %s from net %s\n", + libcfs_nid2str(best_lpni->lpni_nid), + libcfs_net2str(best_lpni->lpni_net->net_id)); + return -EHOSTUNREACH; + } + } + + sd->sd_best_ni = best_ni; + + /* Set preferred NI if necessary. */ + lnet_set_non_mr_pref_nid(sd); + + return 0; +} + + +/* + * Source not specified + * Local destination + * Non-MR Peer + * + * always use the same source NID for NMR peers + * If we've talked to that peer before then we already have a preferred + * source NI associated with it. Otherwise, we select a preferred local NI + * and store it in the peer + */ +static int +lnet_handle_any_local_nmr_dst(struct lnet_send_data *sd) +{ + int rc; + + /* sd->sd_best_lpni is already set to the final destination */ /* - * lnet_msg_commit assigns the correct cpt to the message, which - * is used to decrement the correct refcount on the ni when it's - * time to return the credits + * At this point we should've created the peer ni and peer. If we + * can't find it, then something went wrong. Instead of assert + * output a relevant message and fail the send */ - lnet_msg_commit(msg, cpt); + if (!sd->sd_best_lpni) { + CERROR("Internal fault. Unable to send msg %s to %s. " + "NID not known\n", + lnet_msgtyp2str(sd->sd_msg->msg_type), + libcfs_nid2str(sd->sd_dst_nid)); + return -EFAULT; + } + + rc = lnet_select_preferred_best_ni(sd); + if (!rc) + rc = lnet_handle_send(sd); + return rc; +} + +static int +lnet_handle_any_mr_dsta(struct lnet_send_data *sd) +{ /* - * If we are routing the message then we don't need to overwrite - * the src_nid since it would've been set at the origin. Otherwise - * we are the originator so we need to set it. + * NOTE we've already handled the remote peer case. So we only + * need to worry about the local case here. + * + * if we're sending a response, ACK or reply, we need to send it + * to the destination NID given to us. At this point we already + * have the peer_ni we're suppose to send to, so just find the + * best_ni on the peer net and use that. Since we're sending to an + * MR peer then we can just run the selection algorithm on our + * local NIs and pick the best one. */ - if (!msg->msg_routing) - msg->msg_hdr.src_nid = cpu_to_le64(msg->msg_txni->ni_nid); + if (sd->sd_send_case & SND_RESP) { + sd->sd_best_ni = + lnet_find_best_ni_on_spec_net(NULL, sd->sd_peer, + sd->sd_best_lpni->lpni_peer_net, + sd->sd_md_cpt, true); + + if (!sd->sd_best_ni) { + /* + * We're not going to deal with not able to send + * a response to the provided final destination + */ + CERROR("Can't send response to %s. " + "No local NI available\n", + libcfs_nid2str(sd->sd_dst_nid)); + return -EHOSTUNREACH; + } + + return lnet_handle_send(sd); + } + + /* + * If we get here that means we're sending a fresh request, PUT or + * GET, so we need to run our standard selection algorithm. + * First find the best local interface that's on any of the peer's + * networks. + */ + sd->sd_best_ni = lnet_find_best_ni_on_local_net(sd->sd_peer, + sd->sd_md_cpt); + if (sd->sd_best_ni) { + sd->sd_best_lpni = + lnet_find_best_lpni_on_net(sd, sd->sd_peer, + sd->sd_best_ni->ni_net->net_id); - if (routing) { - msg->msg_target_is_router = 1; - msg->msg_target.pid = LNET_PID_LUSTRE; - /* - * since we're routing we want to ensure that the - * msg_hdr.dest_nid is set to the final destination. When - * the router receives this message it knows how to route - * it. - */ - msg->msg_hdr.dest_nid = - cpu_to_le64(final_dst ? final_dst->lpni_nid : dst_nid); - } else { /* - * if we're not routing set the dest_nid to the best peer - * ni that we picked earlier in the algorithm. + * if we're successful in selecting a peer_ni on the local + * network, then send to it. Otherwise fall through and + * try and see if we can reach it over another routed + * network */ - msg->msg_hdr.dest_nid = cpu_to_le64(msg->msg_txpeer->lpni_nid); + if (sd->sd_best_lpni) { + /* + * in case we initially started with a routed + * destination, let's reset to local + */ + sd->sd_send_case &= ~REMOTE_DST; + sd->sd_send_case |= LOCAL_DST; + return lnet_handle_send(sd); + } + + CERROR("Internal Error. Expected to have a best_lpni: " + "%s -> %s\n", + libcfs_nid2str(sd->sd_src_nid), + libcfs_nid2str(sd->sd_dst_nid)); + + return -EFAULT; } - rc = lnet_post_send_locked(msg, 0); + /* + * Peer doesn't have a local network. Let's see if there is + * a remote network we can reach it on. + */ + return PASS_THROUGH; +} - if (!rc) - CDEBUG(D_NET, "TRACE: %s(%s:%s) -> %s(%s:%s) : %s\n", - libcfs_nid2str(msg->msg_hdr.src_nid), - libcfs_nid2str(msg->msg_txni->ni_nid), - libcfs_nid2str(src_nid), - libcfs_nid2str(msg->msg_hdr.dest_nid), - libcfs_nid2str(dst_nid), - libcfs_nid2str(msg->msg_txpeer->lpni_nid), - lnet_msgtyp2str(msg->msg_type)); +/* + * Case 1: + * Source NID not specified + * Local destination + * MR peer + * + * Case 2: + * Source NID not speified + * Remote destination + * MR peer + * + * In both of these cases if we're sending a response, ACK or REPLY, then + * we need to send to the destination NID provided. + * + * In the remote case let's deal with MR routers. + * + */ - lnet_net_unlock(cpt); +static int +lnet_handle_any_mr_dst(struct lnet_send_data *sd) +{ + int rc = 0; + struct lnet_peer *gw_peer = NULL; + struct lnet_peer_ni *gw_lpni = NULL; + + /* + * handle sending a response to a remote peer here so we don't + * have to worry about it if we hit lnet_handle_any_mr_dsta() + */ + if (sd->sd_send_case & REMOTE_DST && + sd->sd_send_case & SND_RESP) { + struct lnet_peer_ni *gw; + struct lnet_peer *gw_peer; + + rc = lnet_handle_find_routed_path(sd, sd->sd_dst_nid, &gw, + &gw_peer); + if (rc < 0) { + CERROR("Can't send response to %s. " + "No route available\n", + libcfs_nid2str(sd->sd_dst_nid)); + return -EHOSTUNREACH; + } + + sd->sd_best_lpni = gw; + sd->sd_peer = gw_peer; + + return lnet_handle_send(sd); + } + + /* + * Even though the NID for the peer might not be on a local network, + * since the peer is MR there could be other interfaces on the + * local network. In that case we'd still like to prefer the local + * network over the routed network. If we're unable to do that + * then we select the best router among the different routed networks, + * and if the router is MR then we can deal with it as such. + */ + rc = lnet_handle_any_mr_dsta(sd); + if (rc != PASS_THROUGH) + return rc; + + /* + * TODO; One possible enhancement is to run the selection + * algorithm on the peer. However for remote peers the credits are + * not decremented, so we'll be basically going over the peer NIs + * in round robin. An MR router will run the selection algorithm + * on the next-hop interfaces. + */ + rc = lnet_handle_find_routed_path(sd, sd->sd_dst_nid, &gw_lpni, + &gw_peer); + if (rc < 0) + return rc; + + sd->sd_send_case &= ~LOCAL_DST; + sd->sd_send_case |= REMOTE_DST; + + sd->sd_peer = gw_peer; + sd->sd_best_lpni = gw_lpni; + + return lnet_handle_send(sd); +} + +/* + * Source not specified + * Remote destination + * Non-MR peer + * + * Must send to the specified peer NID using the same source NID that + * we've used before. If it's the first time to talk to that peer then + * find the source NI and assign it as preferred to that peer + */ +static int +lnet_handle_any_router_nmr_dst(struct lnet_send_data *sd) +{ + int rc; + struct lnet_peer_ni *gw_lpni = NULL; + struct lnet_peer *gw_peer = NULL; + + /* + * Let's set if we have a preferred NI to talk to this NMR peer + */ + sd->sd_best_ni = lnet_find_existing_preferred_best_ni(sd); + + /* + * find the router and that'll find the best NI if we didn't find + * it already. + */ + rc = lnet_handle_find_routed_path(sd, sd->sd_dst_nid, &gw_lpni, + &gw_peer); + if (rc < 0) + return rc; + + /* + * set the best_ni we've chosen as the preferred one for + * this peer + */ + lnet_set_non_mr_pref_nid(sd); + + /* we'll be sending to the gw */ + sd->sd_best_lpni = gw_lpni; + sd->sd_peer = gw_peer; + + return lnet_handle_send(sd); +} + +static int +lnet_handle_send_case_locked(struct lnet_send_data *sd) +{ + /* + * turn off the SND_RESP bit. + * It will be checked in the case handling + */ + __u32 send_case = sd->sd_send_case &= ~SND_RESP ; + + CDEBUG(D_NET, "Source %s%s to %s %s %s destination\n", + (send_case & SRC_SPEC) ? "Specified: " : "ANY", + (send_case & SRC_SPEC) ? libcfs_nid2str(sd->sd_src_nid) : "", + (send_case & MR_DST) ? "MR: " : "NMR: ", + libcfs_nid2str(sd->sd_dst_nid), + (send_case & LOCAL_DST) ? "local" : "routed"); + + switch (send_case) { + /* + * For all cases where the source is specified, we should always + * use the destination NID, whether it's an MR destination or not, + * since we're continuing a series of related messages for the + * same RPC + */ + case SRC_SPEC_LOCAL_NMR_DST: + return lnet_handle_spec_local_nmr_dst(sd); + case SRC_SPEC_LOCAL_MR_DST: + return lnet_handle_spec_local_mr_dst(sd); + case SRC_SPEC_ROUTER_NMR_DST: + case SRC_SPEC_ROUTER_MR_DST: + return lnet_handle_spec_router_dst(sd); + case SRC_ANY_LOCAL_NMR_DST: + return lnet_handle_any_local_nmr_dst(sd); + case SRC_ANY_LOCAL_MR_DST: + case SRC_ANY_ROUTER_MR_DST: + return lnet_handle_any_mr_dst(sd); + case SRC_ANY_ROUTER_NMR_DST: + return lnet_handle_any_router_nmr_dst(sd); + default: + CERROR("Unknown send case\n"); + return -1; + } +} + +static int +lnet_select_pathway(lnet_nid_t src_nid, lnet_nid_t dst_nid, + struct lnet_msg *msg, lnet_nid_t rtr_nid) +{ + struct lnet_peer_ni *lpni; + struct lnet_peer *peer; + struct lnet_send_data send_data; + int cpt, rc; + int md_cpt; + __u32 send_case = 0; + + memset(&send_data, 0, sizeof(send_data)); + + /* + * get an initial CPT to use for locking. The idea here is not to + * serialize the calls to select_pathway, so that as many + * operations can run concurrently as possible. To do that we use + * the CPT where this call is being executed. Later on when we + * determine the CPT to use in lnet_message_commit, we switch the + * lock and check if there was any configuration change. If none, + * then we proceed, if there is, then we restart the operation. + */ + cpt = lnet_net_lock_current(); + + md_cpt = lnet_cpt_of_md(msg->msg_md, msg->msg_offset); + if (md_cpt == CFS_CPT_ANY) + md_cpt = cpt; + +again: + + /* + * If we're being asked to send to the loopback interface, there + * is no need to go through any selection. We can just shortcut + * the entire process and send over lolnd + */ + if (LNET_NETTYP(LNET_NIDNET(dst_nid)) == LOLND) { + /* No send credit hassles with LOLND */ + lnet_ni_addref_locked(the_lnet.ln_loni, cpt); + msg->msg_hdr.dest_nid = cpu_to_le64(the_lnet.ln_loni->ni_nid); + if (!msg->msg_routing) + msg->msg_hdr.src_nid = + cpu_to_le64(the_lnet.ln_loni->ni_nid); + msg->msg_target.nid = the_lnet.ln_loni->ni_nid; + lnet_msg_commit(msg, cpt); + msg->msg_txni = the_lnet.ln_loni; + lnet_net_unlock(cpt); + + return LNET_CREDIT_OK; + } + + /* + * find an existing peer_ni, or create one and mark it as having been + * created due to network traffic. This call will create the + * peer->peer_net->peer_ni tree. + */ + lpni = lnet_nid2peerni_locked(dst_nid, LNET_NID_ANY, cpt); + if (IS_ERR(lpni)) { + lnet_net_unlock(cpt); + return PTR_ERR(lpni); + } + + /* + * Now that we have a peer_ni, check if we want to discover + * the peer. Traffic to the LNET_RESERVED_PORTAL should not + * trigger discovery. + */ + peer = lpni->lpni_peer_net->lpn_peer; + if (lnet_msg_discovery(msg) && !lnet_peer_is_uptodate(peer)) { + lnet_nid_t primary_nid; + rc = lnet_discover_peer_locked(lpni, cpt, false); + if (rc) { + lnet_peer_ni_decref_locked(lpni); + lnet_net_unlock(cpt); + return rc; + } + /* The peer may have changed. */ + peer = lpni->lpni_peer_net->lpn_peer; + /* queue message and return */ + msg->msg_src_nid_param = src_nid; + msg->msg_rtr_nid_param = rtr_nid; + msg->msg_sending = 0; + list_add_tail(&msg->msg_list, &peer->lp_dc_pendq); + lnet_peer_ni_decref_locked(lpni); + primary_nid = peer->lp_primary_nid; + lnet_net_unlock(cpt); + + CDEBUG(D_NET, "%s pending discovery\n", + libcfs_nid2str(primary_nid)); + + return LNET_DC_WAIT; + } + lnet_peer_ni_decref_locked(lpni); + + /* If peer is not healthy then can not send anything to it */ + if (!lnet_is_peer_healthy_locked(peer)) { + lnet_net_unlock(cpt); + return -EHOSTUNREACH; + } + + /* + * Identify the different send cases + */ + if (src_nid == LNET_NID_ANY) + send_case |= SRC_ANY; + else + send_case |= SRC_SPEC; + + if (lnet_get_net_locked(LNET_NIDNET(dst_nid))) + send_case |= LOCAL_DST; + else + send_case |= REMOTE_DST; + + if (!lnet_peer_is_multi_rail(peer)) + send_case |= NMR_DST; + else + send_case |= MR_DST; + + if (msg->msg_type == LNET_MSG_REPLY || + msg->msg_type == LNET_MSG_ACK) + send_case |= SND_RESP; + + /* assign parameters to the send_data */ + send_data.sd_msg = msg; + send_data.sd_rtr_nid = rtr_nid; + send_data.sd_src_nid = src_nid; + send_data.sd_dst_nid = dst_nid; + send_data.sd_best_lpni = lpni; + /* + * keep a pointer to the final destination in case we're going to + * route, so we'll need to access it later + */ + send_data.sd_final_dst_lpni = lpni; + send_data.sd_peer = peer; + send_data.sd_md_cpt = md_cpt; + send_data.sd_cpt = cpt; + send_data.sd_send_case = send_case; + + rc = lnet_handle_send_case_locked(&send_data); + + if (rc == REPEAT_SEND) + goto again; + + lnet_net_unlock(send_data.sd_cpt); return rc; } -- 1.8.3.1