Commit c9a5d243 authored by Karsten Graul's avatar Karsten Graul Committed by David S. Miller
Browse files

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: default avatarKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: default avatarUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1551c95b

net/smc/smc_llc.c

+80 −1
Original line number Diff line number Diff line
@@ -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);

}

net/smc/smc_wr.c

+1 −1
Original line number Diff line number Diff line
@@ -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))

net/smc/smc_wr.h

+1 −0
Original line number Diff line number Diff line
@@ -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);