From c9a5d243035161f06175a7c6d487c9860e0f179a Mon Sep 17 00:00:00 2001 From: Karsten Graul Date: Sun, 3 May 2020 14:38:46 +0200 Subject: net/smc: delete an asymmetric link as SMC server When a link group moved from asymmetric to symmetric state then the dangling asymmetric link can be deleted. Add smc_llc_find_asym_link() to find the respective link and add smc_llc_delete_asym_link() to delete it. Signed-off-by: Karsten Graul Reviewed-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/smc_llc.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- net/smc/smc_wr.c | 2 +- net/smc/smc_wr.h | 1 + 3 files changed, 82 insertions(+), 2 deletions(-) (limited to 'net/smc') diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index 1fefee55e293..9d102c912be9 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -863,6 +863,85 @@ static void smc_llc_process_cli_add_link(struct smc_link_group *lgr) mutex_unlock(&lgr->llc_conf_mutex); } +/* find the asymmetric link when 3 links are established */ +static struct smc_link *smc_llc_find_asym_link(struct smc_link_group *lgr) +{ + int asym_idx = -ENOENT; + int i, j, k; + bool found; + + /* determine asymmetric link */ + found = false; + for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) { + for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) { + if (!smc_link_usable(&lgr->lnk[i]) || + !smc_link_usable(&lgr->lnk[j])) + continue; + if (!memcmp(lgr->lnk[i].gid, lgr->lnk[j].gid, + SMC_GID_SIZE)) { + found = true; /* asym_lnk is i or j */ + break; + } + } + if (found) + break; + } + if (!found) + goto out; /* no asymmetric link */ + for (k = 0; k < SMC_LINKS_PER_LGR_MAX; k++) { + if (!smc_link_usable(&lgr->lnk[k])) + continue; + if (k != i && + !memcmp(lgr->lnk[i].peer_gid, lgr->lnk[k].peer_gid, + SMC_GID_SIZE)) { + asym_idx = i; + break; + } + if (k != j && + !memcmp(lgr->lnk[j].peer_gid, lgr->lnk[k].peer_gid, + SMC_GID_SIZE)) { + asym_idx = j; + break; + } + } +out: + return (asym_idx < 0) ? NULL : &lgr->lnk[asym_idx]; +} + +static void smc_llc_delete_asym_link(struct smc_link_group *lgr) +{ + struct smc_link *lnk_new = NULL, *lnk_asym; + struct smc_llc_qentry *qentry; + int rc; + + lnk_asym = smc_llc_find_asym_link(lgr); + if (!lnk_asym) + return; /* no asymmetric link */ + if (!smc_link_downing(&lnk_asym->state)) + return; + /* tbd: lnk_new = smc_switch_conns(lgr, lnk_asym, false); */ + smc_wr_tx_wait_no_pending_sends(lnk_asym); + if (!lnk_new) + goto out_free; + /* change flow type from ADD_LINK into DEL_LINK */ + lgr->llc_flow_lcl.type = SMC_LLC_FLOW_DEL_LINK; + rc = smc_llc_send_delete_link(lnk_new, lnk_asym->link_id, SMC_LLC_REQ, + true, SMC_LLC_DEL_NO_ASYM_NEEDED); + if (rc) { + smcr_link_down_cond(lnk_new); + goto out_free; + } + qentry = smc_llc_wait(lgr, lnk_new, SMC_LLC_WAIT_TIME, + SMC_LLC_DELETE_LINK); + if (!qentry) { + smcr_link_down_cond(lnk_new); + goto out_free; + } + smc_llc_flow_qentry_del(&lgr->llc_flow_lcl); +out_free: + smcr_link_clear(lnk_asym); +} + static int smc_llc_srv_rkey_exchange(struct smc_link *link, struct smc_link *link_new) { @@ -1014,7 +1093,7 @@ static void smc_llc_process_srv_add_link(struct smc_link_group *lgr) rc = smc_llc_srv_add_link(link); if (!rc && lgr->type == SMC_LGR_SYMMETRIC) { /* delete any asymmetric link */ - /* tbd: smc_llc_delete_asym_link(lgr); */ + smc_llc_delete_asym_link(lgr); } mutex_unlock(&lgr->llc_conf_mutex); } diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c index 031e6c9561b1..3fd27bea4f7a 100644 --- a/net/smc/smc_wr.c +++ b/net/smc/smc_wr.c @@ -61,7 +61,7 @@ static inline bool smc_wr_is_tx_pend(struct smc_link *link) } /* wait till all pending tx work requests on the given link are completed */ -static inline int smc_wr_tx_wait_no_pending_sends(struct smc_link *link) +int smc_wr_tx_wait_no_pending_sends(struct smc_link *link) { if (wait_event_timeout(link->wr_tx_wait, !smc_wr_is_tx_pend(link), SMC_WR_TX_WAIT_PENDING_TIME)) diff --git a/net/smc/smc_wr.h b/net/smc/smc_wr.h index 3ac99c898418..f7eaeb3391f3 100644 --- a/net/smc/smc_wr.h +++ b/net/smc/smc_wr.h @@ -106,6 +106,7 @@ void smc_wr_tx_dismiss_slots(struct smc_link *lnk, u8 wr_rx_hdr_type, smc_wr_tx_filter filter, smc_wr_tx_dismisser dismisser, unsigned long data); +int smc_wr_tx_wait_no_pending_sends(struct smc_link *link); int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler); int smc_wr_rx_post_init(struct smc_link *link); -- cgit v1.2.3