From ba203e81c1543d0d39d6de39fd5cb9d6af7cc283 Mon Sep 17 00:00:00 2001 From: Olaf Weber Date: Fri, 27 Jan 2017 16:24:04 +0100 Subject: [PATCH] LU-9480 lnet: refactor lnet_add_peer_ni() Refactor lnet_add_peer_ni() and the functions called by it. In particular, lnet_peer_add_nid() adds an lnet_peer_ni to an existing lnet_peer, lnet_peer_add() adds a new lnet_peer. lnet_find_or_create_peer_locked() is removed. Test-Parameters: trivial Signed-off-by: Olaf Weber Change-Id: Iffcbf9ffc26460afc544f102bd0e0a56e23a83f3 Reviewed-on: https://review.whamcloud.com/25780 Reviewed-by: Olaf Weber Reviewed-by: Amir Shehata Tested-by: Amir Shehata --- lnet/include/lnet/lib-lnet.h | 1 - lnet/lnet/lib-move.c | 13 ++- lnet/lnet/peer.c | 229 ++++++++++++++++--------------------------- 3 files changed, 92 insertions(+), 151 deletions(-) diff --git a/lnet/include/lnet/lib-lnet.h b/lnet/include/lnet/lib-lnet.h index eb25244..65bf460 100644 --- a/lnet/include/lnet/lib-lnet.h +++ b/lnet/include/lnet/lib-lnet.h @@ -823,7 +823,6 @@ __u32 lnet_get_dlc_seq_locked(void); struct lnet_peer_ni *lnet_get_next_peer_ni_locked(struct lnet_peer *peer, struct lnet_peer_net *peer_net, struct lnet_peer_ni *prev); -struct lnet_peer *lnet_find_or_create_peer_locked(lnet_nid_t dst_nid, int cpt); struct lnet_peer_ni *lnet_nid2peerni_locked(lnet_nid_t nid, int cpt); struct lnet_peer_ni *lnet_nid2peerni_ex(lnet_nid_t nid, int cpt); struct lnet_peer_ni *lnet_find_peer_ni_locked(lnet_nid_t nid); diff --git a/lnet/lnet/lib-move.c b/lnet/lnet/lib-move.c index 5863836..2779eea 100644 --- a/lnet/lnet/lib-move.c +++ b/lnet/lnet/lib-move.c @@ -1443,11 +1443,18 @@ again: return -ESHUTDOWN; } - peer = lnet_find_or_create_peer_locked(dst_nid, cpt); - if (IS_ERR(peer)) { + /* + * 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. + */ + lpni = lnet_nid2peerni_locked(dst_nid, cpt); + if (IS_ERR(lpni)) { lnet_net_unlock(cpt); - return PTR_ERR(peer); + return PTR_ERR(lpni); } + peer = lpni->lpni_peer_net->lpn_peer; + 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)) { diff --git a/lnet/lnet/peer.c b/lnet/lnet/peer.c index 4b3568b..4310f8c 100644 --- a/lnet/lnet/peer.c +++ b/lnet/lnet/peer.c @@ -536,25 +536,6 @@ lnet_find_peer_ni_locked(lnet_nid_t nid) return lpni; } -struct lnet_peer * -lnet_find_or_create_peer_locked(lnet_nid_t dst_nid, int cpt) -{ - struct lnet_peer_ni *lpni; - struct lnet_peer *lp; - - lpni = lnet_find_peer_ni_locked(dst_nid); - if (!lpni) { - lpni = lnet_nid2peerni_locked(dst_nid, cpt); - if (IS_ERR(lpni)) - return ERR_CAST(lpni); - } - - lp = lpni->lpni_peer_net->lpn_peer; - lnet_peer_ni_decref_locked(lpni); - - return lp; -} - struct lnet_peer_ni * lnet_get_peer_ni_idx_locked(int idx, struct lnet_peer_net **lpn, struct lnet_peer **lp) @@ -767,27 +748,26 @@ out_enomem: return -ENOMEM; } +/* + * Create a new peer, with nid as its primary nid. + * + * It is not an error if the peer already exists, provided that the + * given nid is the primary NID. + * + * Call with the lnet_api_mutex held. + */ static int -lnet_add_prim_lpni(lnet_nid_t nid) +lnet_peer_add(lnet_nid_t nid, bool mr) { - int rc = 0; - struct lnet_peer *peer; + struct lnet_peer *lp; struct lnet_peer_ni *lpni; + int rc; LASSERT(nid != LNET_NID_ANY); /* - * lookup the NID and its peer - * if the peer doesn't exist, create it. - * if this is a non-MR peer then change its state to MR and exit. - * if this is an MR peer and it's a primary NI: NO-OP. - * if this is an MR peer and it's not a primary NI. Operation not - * allowed. - * - * The adding and deleting of peer nis is being serialized through - * the api_mutex. So we can look up peers with the mutex locked - * safely. Only when we need to change the ptable, do we need to - * exclusively lock the lnet_net_lock() + * No need for the lnet_net_lock here, because the + * lnet_api_mutex is held. */ lpni = lnet_find_peer_ni_locked(nid); if (!lpni) { @@ -795,103 +775,69 @@ lnet_add_prim_lpni(lnet_nid_t nid) if (rc != 0) return rc; lpni = lnet_find_peer_ni_locked(nid); + LASSERT(lpni); } - - LASSERT(lpni); - + lp = lpni->lpni_peer_net->lpn_peer; lnet_peer_ni_decref_locked(lpni); - peer = lpni->lpni_peer_net->lpn_peer; - - /* - * If we found a lpni with the same nid as the NID we're trying to - * create, then we're trying to create an already existing lpni - * that belongs to a different peer - */ - if (peer->lp_primary_nid != nid) + /* A found peer must have this primary NID */ + if (lp->lp_primary_nid != nid) return -EEXIST; /* - * if we found an lpni that is not a multi-rail, which could occur + * If we found an lpni that is not a multi-rail, which could occur * if lpni is already created as a non-mr lpni or we just created * it, then make sure you indicate that this lpni is a primary mr * capable peer. * * TODO: update flags if necessary */ - if (!peer->lp_multi_rail && peer->lp_primary_nid == nid) - peer->lp_multi_rail = true; + if (mr && !lp->lp_multi_rail) { + lp->lp_multi_rail = true; + } else if (!mr && lp->lp_multi_rail) { + /* The mr state is sticky. */ + CDEBUG(D_NET, "Cannot clear multi-flag from peer %s\n", + libcfs_nid2str(nid)); + } - return rc; + return 0; } static int -lnet_add_peer_ni_to_prim_lpni(lnet_nid_t prim_nid, lnet_nid_t nid) +lnet_peer_add_nid(struct lnet_peer *lp, lnet_nid_t nid, bool mr) { - struct lnet_peer *peer, *primary_peer; - struct lnet_peer_ni *lpni = NULL, *klpni = NULL; - - LASSERT(prim_nid != LNET_NID_ANY && nid != LNET_NID_ANY); + struct lnet_peer_ni *lpni; - /* - * key nid must be created by this point. If not then this - * operation is not permitted - */ - klpni = lnet_find_peer_ni_locked(prim_nid); - if (!klpni) - return -ENOENT; + LASSERT(lp); + LASSERT(nid != LNET_NID_ANY); - lnet_peer_ni_decref_locked(klpni); + if (!mr && !lp->lp_multi_rail) { + CERROR("Cannot add nid %s to non-multi-rail peer %s\n", + libcfs_nid2str(nid), + libcfs_nid2str(lp->lp_primary_nid)); + return -EPERM; + } - primary_peer = klpni->lpni_peer_net->lpn_peer; + if (!lp->lp_multi_rail) + lp->lp_multi_rail = true; lpni = lnet_find_peer_ni_locked(nid); - if (lpni) { - lnet_peer_ni_decref_locked(lpni); - - peer = lpni->lpni_peer_net->lpn_peer; - /* - * lpni already exists in the system but it belongs to - * a different peer. We can't re-added it - */ - if (peer->lp_primary_nid != prim_nid && peer->lp_multi_rail) { - CERROR("Cannot add NID %s owned by peer %s to peer %s\n", - libcfs_nid2str(lpni->lpni_nid), - libcfs_nid2str(peer->lp_primary_nid), - libcfs_nid2str(prim_nid)); - return -EEXIST; - } else if (peer->lp_primary_nid == prim_nid) { - /* - * found a peer_ni that is already part of the - * peer. This is a no-op operation. - */ - return 0; - } - - /* - * TODO: else if (peer->lp_primary_nid != prim_nid && - * !peer->lp_multi_rail) - * peer is not an MR peer and it will be moved in the next - * step to klpni, so update its flags accordingly. - * lnet_move_peer_ni() - */ - - /* - * TODO: call lnet_update_peer() from here to update the - * flags. This is the case when the lpni you're trying to - * add is already part of the peer. This could've been - * added by the DD previously, so go ahead and do any - * updates to the state if necessary - */ + if (!lpni) + return lnet_peer_setup_hierarchy(lp, NULL, nid); + if (lpni->lpni_peer_net->lpn_peer != lp) { + struct lnet_peer *lp2 = lpni->lpni_peer_net->lpn_peer; + CERROR("Cannot add NID %s owned by peer %s to peer %s\n", + libcfs_nid2str(lpni->lpni_nid), + libcfs_nid2str(lp2->lp_primary_nid), + libcfs_nid2str(lp->lp_primary_nid)); + return -EEXIST; } - /* - * When we get here we either have found an existing lpni, which - * we can switch to the new peer. Or we need to create one and - * add it to the new peer - */ - return lnet_peer_setup_hierarchy(primary_peer, lpni, nid); + CDEBUG(D_NET, "NID %s is already owned by peer %s\n", + libcfs_nid2str(lpni->lpni_nid), + libcfs_nid2str(lp->lp_primary_nid)); + return 0; } /* @@ -923,61 +869,50 @@ lnet_peer_ni_traffic_add(lnet_nid_t nid) } -static int -lnet_peer_ni_add_non_mr(lnet_nid_t nid) -{ - struct lnet_peer_ni *lpni; - - lpni = lnet_find_peer_ni_locked(nid); - if (lpni) { - CERROR("Cannot add %s as non-mr when it already exists\n", - libcfs_nid2str(nid)); - lnet_peer_ni_decref_locked(lpni); - return -EEXIST; - } - - return lnet_peer_setup_hierarchy(NULL, NULL, nid); -} - /* * Implementation of IOC_LIBCFS_ADD_PEER_NI. * * This API handles the following combinations: - * Create a primary NI if only the prim_nid is provided - * Create or add an lpni to a primary NI. Primary NI must've already - * been created - * Create a non-MR peer. + * Create a peer with its primary NI if only the prim_nid is provided + * Add a NID to a peer identified by the prim_nid. The peer identified + * by the prim_nid must already exist. + * The peer being created may be non-MR. + * + * The caller must hold ln_api_mutex. This prevents the peer from + * being created/modified/deleted by a different thread. */ int lnet_add_peer_ni(lnet_nid_t prim_nid, lnet_nid_t nid, bool mr) { + struct lnet_peer *lp = NULL; + struct lnet_peer_ni *lpni; + + /* The prim_nid must always be specified */ + if (prim_nid == LNET_NID_ANY) + return -EINVAL; + /* - * Caller trying to setup an MR like peer hierarchy but - * specifying it to be non-MR. This is not allowed. + * If nid isn't specified, we must create a new peer with + * prim_nid as its primary nid. */ - if (prim_nid != LNET_NID_ANY && - nid != LNET_NID_ANY && !mr) - return -EPERM; - - /* Add the primary NID of a peer */ - if (prim_nid != LNET_NID_ANY && - nid == LNET_NID_ANY && mr) - return lnet_add_prim_lpni(prim_nid); + if (nid == LNET_NID_ANY) + return lnet_peer_add(prim_nid, mr); - /* Add a NID to an existing peer */ - if (prim_nid != LNET_NID_ANY && - nid != LNET_NID_ANY && mr) - return lnet_add_peer_ni_to_prim_lpni(prim_nid, nid); + /* Look up the prim_nid, which must exist. */ + lpni = lnet_find_peer_ni_locked(prim_nid); + if (!lpni) + return -ENOENT; + lnet_peer_ni_decref_locked(lpni); + lp = lpni->lpni_peer_net->lpn_peer; - /* Add a non-MR peer NI */ - if (((prim_nid != LNET_NID_ANY && - nid == LNET_NID_ANY) || - (prim_nid == LNET_NID_ANY && - nid != LNET_NID_ANY)) && !mr) - return lnet_peer_ni_add_non_mr(prim_nid != LNET_NID_ANY ? - prim_nid : nid); + if (lp->lp_primary_nid != prim_nid) { + CDEBUG(D_NET, "prim_nid %s is not primary for peer %s\n", + libcfs_nid2str(prim_nid), + libcfs_nid2str(lp->lp_primary_nid)); + return -ENODEV; + } - return 0; + return lnet_peer_add_nid(lp, nid, mr); } /* -- 1.8.3.1