From 4d4be7a389cce11e5abaf72f069f59aca18ab044 Mon Sep 17 00:00:00 2001 From: Olaf Weber Date: Fri, 27 Jan 2017 16:23:51 +0100 Subject: [PATCH] LU-9480 lnet: refactor lnet_del_peer_ni() Refactor lnet_del_peer_ni(). In particular break out the code that removes an lnet_peer_ni from an lnet_peer and put it into a separate function, lnet_peer_del_nid(). Test-Parameters: trivial Signed-off-by: Olaf Weber Change-Id: Id5988b308afb093f83cc2e7029d3f2961171c906 Reviewed-on: https://review.whamcloud.com/25779 Reviewed-by: Olaf Weber Reviewed-by: Amir Shehata Tested-by: Amir Shehata --- lnet/lnet/peer.c | 96 +++++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 71 insertions(+), 25 deletions(-) diff --git a/lnet/lnet/peer.c b/lnet/lnet/peer.c index 7afcf6e..4b3568b 100644 --- a/lnet/lnet/peer.c +++ b/lnet/lnet/peer.c @@ -287,7 +287,7 @@ lnet_peer_ni_del_locked(struct lnet_peer_ni *lpni) * * The last reference may be lost in a place where the * lnet_net_lock locks only a single cpt, and that cpt may not - * be lpni->lpni_cpt. So the zombie list of this peer_table + * be lpni->lpni_cpt. So the zombie list of lnet_peer_table * has its own lock. */ spin_lock(&ptable->pt_zombie_lock); @@ -338,6 +338,61 @@ lnet_peer_del_locked(struct lnet_peer *peer) return rc2; } +static int +lnet_peer_del(struct lnet_peer *peer) +{ + lnet_net_lock(LNET_LOCK_EX); + lnet_peer_del_locked(peer); + lnet_net_unlock(LNET_LOCK_EX); + + return 0; +} + +/* + * Delete a NID from a peer. + * Implements a few sanity checks. + * Call with ln_api_mutex held. + */ +static int +lnet_peer_del_nid(struct lnet_peer *lp, lnet_nid_t nid) +{ + struct lnet_peer *lp2; + struct lnet_peer_ni *lpni; + + lpni = lnet_find_peer_ni_locked(nid); + if (!lpni) { + CERROR("Cannot remove unknown nid %s from peer %s\n", + libcfs_nid2str(nid), + libcfs_nid2str(lp->lp_primary_nid)); + return -ENOENT; + } + lnet_peer_ni_decref_locked(lpni); + lp2 = lpni->lpni_peer_net->lpn_peer; + if (lp2 != lp) { + CERROR("Nid %s is attached to peer %s, not peer %s\n", + libcfs_nid2str(nid), + libcfs_nid2str(lp2->lp_primary_nid), + libcfs_nid2str(lp->lp_primary_nid)); + return -EINVAL; + } + + /* + * This function only allows deletion of the primary NID if it + * is the only NID. + */ + if (nid == lp->lp_primary_nid && lnet_get_num_peer_nis(lp) != 1) { + CERROR("Cannot delete primary NID %s from multi-NID peer\n", + libcfs_nid2str(nid)); + return -EINVAL; + } + + lnet_net_lock(LNET_LOCK_EX); + lnet_peer_ni_del_locked(lpni); + lnet_net_unlock(LNET_LOCK_EX); + + return 0; +} + static void lnet_peer_table_cleanup_locked(struct lnet_net *net, struct lnet_peer_table *ptable) @@ -932,45 +987,36 @@ lnet_add_peer_ni(lnet_nid_t prim_nid, lnet_nid_t nid, bool mr) * Delete a NI from a peer if both prim_nid and nid are provided. * Delete a peer if only prim_nid is provided. * Delete a peer if its primary nid is provided. + * + * The caller must hold ln_api_mutex. This prevents the peer from + * being modified/deleted by a different thread. */ int lnet_del_peer_ni(lnet_nid_t prim_nid, lnet_nid_t nid) { - lnet_nid_t local_nid; - struct lnet_peer *peer; + struct lnet_peer *lp; struct lnet_peer_ni *lpni; - int rc; if (prim_nid == LNET_NID_ANY) return -EINVAL; - local_nid = (nid != LNET_NID_ANY) ? nid : prim_nid; - - lpni = lnet_find_peer_ni_locked(local_nid); + lpni = lnet_find_peer_ni_locked(prim_nid); if (!lpni) - return -EINVAL; + return -ENOENT; lnet_peer_ni_decref_locked(lpni); + lp = lpni->lpni_peer_net->lpn_peer; - peer = lpni->lpni_peer_net->lpn_peer; - LASSERT(peer != NULL); - - if (peer->lp_primary_nid == lpni->lpni_nid) { - /* - * deleting the primary ni is equivalent to deleting the - * entire peer - */ - lnet_net_lock(LNET_LOCK_EX); - rc = lnet_peer_del_locked(peer); - lnet_net_unlock(LNET_LOCK_EX); - - return rc; + if (prim_nid != lp->lp_primary_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; } - lnet_net_lock(LNET_LOCK_EX); - rc = lnet_peer_ni_del_locked(lpni); - lnet_net_unlock(LNET_LOCK_EX); + if (nid == LNET_NID_ANY || nid == lp->lp_primary_nid) + return lnet_peer_del(lp); - return rc; + return lnet_peer_del_nid(lp, nid); } void -- 1.8.3.1