[PATCH net-next 10/13] net/smc: delete link processing as SMC client

Karsten Graul
2020-05-02T12:36:19Z

Add smc_llc_process_cli_delete_link() to process a DELETE_LINK request
as SMC client. When the request is to delete ALL links then terminate
the whole link group. If not, find the link to delete by its link_id,
send the DELETE_LINK response LLC message and then clear the deleted
link. Finally determine and update the link group state.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
---
net/smc/smc_llc.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 72 insertions(+)

diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index e4e3910a9624..cd57b4fb1842 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -863,6 +863,18 @@ static void smc_llc_process_cli_add_link(struct smc_link_group *lgr)
mutex_unlock(&lgr->llc_conf_mutex);
}

+static int smc_llc_active_link_count(struct smc_link_group *lgr)
+{
+ int i, link_count = 0;
+
+ for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+ if (!smc_link_usable(&lgr->lnk[i]))
+ continue;
+ link_count++;
+ }
+ return link_count;
+}
+
/* find the asymmetric link when 3 links are established */
static struct smc_link *smc_llc_find_asym_link(struct smc_link_group *lgr)
{
@@ -1118,6 +1130,63 @@ static void smc_llc_add_link_work(struct work_struct *work)
smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
}

+static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
+{
+ struct smc_link *lnk_del = NULL, *lnk_asym, *lnk;
+ struct smc_llc_msg_del_link *del_llc;
+ struct smc_llc_qentry *qentry;
+ int active_links;
+ int lnk_idx;
+
+ qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
+ lnk = qentry->link;
+ del_llc = &qentry->msg.delete_link;
+
+ if (del_llc->hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
+ smc_lgr_terminate_sched(lgr);
+ goto out;
+ }
+ mutex_lock(&lgr->llc_conf_mutex);
+ /* delete single link */
+ for (lnk_idx = 0; lnk_idx < SMC_LINKS_PER_LGR_MAX; lnk_idx++) {
+ if (lgr->lnk[lnk_idx].link_id != del_llc->link_num)
+ continue;
+ lnk_del = &lgr->lnk[lnk_idx];
+ break;
+ }
+ del_llc->hd.flags |= SMC_LLC_FLAG_RESP;
+ if (!lnk_del) {
+ /* link was not found */
+ del_llc->reason = htonl(SMC_LLC_DEL_NOLNK);
+ smc_llc_send_message(lnk, &qentry->msg);
+ goto out_unlock;
+ }
+ lnk_asym = smc_llc_find_asym_link(lgr);
+
+ del_llc->reason = 0;
+ smc_llc_send_message(lnk, &qentry->msg); /* response */
+
+ if (smc_link_downing(&lnk_del->state)) {
+ /* tbd: call smc_switch_conns(lgr, lnk_del, false); */
+ smc_wr_tx_wait_no_pending_sends(lnk_del);
+ }
+ smcr_link_clear(lnk_del);
+
+ active_links = smc_llc_active_link_count(lgr);
+ if (lnk_del == lnk_asym) {
+ /* expected deletion of asym link, don't change lgr state */
+ } else if (active_links == 1) {
+ lgr->type = SMC_LGR_SINGLE;
+ } else if (!active_links) {
+ lgr->type = SMC_LGR_NONE;
+ smc_lgr_terminate_sched(lgr);
+ }
+out_unlock:
+ mutex_unlock(&lgr->llc_conf_mutex);
+out:
+ kfree(qentry);
+}
+
static void smc_llc_delete_link_work(struct work_struct *work)
{
struct smc_link_group *lgr = container_of(work, struct smc_link_group,
@@ -1128,6 +1197,9 @@ static void smc_llc_delete_link_work(struct work_struct *work)
smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
goto out;
}
+
+ if (lgr->role == SMC_CLNT)
+ smc_llc_process_cli_delete_link(lgr);
out:
smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
}
--
2.17.1