net/smc: stop links when their GID is removed

With SMC-Rv2 the GID is an IP address that can be deleted from the
device. When an IB_EVENT_GID_CHANGE event is provided then iterate over
all active links and check if their GID is still defined. Otherwise
stop the affected link.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
index 32f9d2fdc47463f1ef02555ae3709fa2e8206c7b..d93055ec17ae86cbaee63cc35943a71a118d1a74 100644 (file)
--- a/net/smc/smc_ib.c
+++ b/net/smc/smc_ib.c
@@ -295,6 +295,58 @@ int smc_ib_determine_gid(struct smc_ib_device *smcibdev, u8 ibport,
        return -ENODEV;
 }
 
+/* check if gid is still defined on smcibdev */
+static bool smc_ib_check_link_gid(u8 gid[SMC_GID_SIZE], bool smcrv2,
+                                 struct smc_ib_device *smcibdev, u8 ibport)
+{
+       const struct ib_gid_attr *attr;
+       bool rc = false;
+       int i;
+
+       for (i = 0; !rc && i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
+               attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, i);
+               if (IS_ERR(attr))
+                       continue;
+
+               rcu_read_lock();
+               if ((!smcrv2 && attr->gid_type == IB_GID_TYPE_ROCE) ||
+                   (smcrv2 && attr->gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP &&
+                    !(ipv6_addr_type((const struct in6_addr *)&attr->gid)
+                                    & IPV6_ADDR_LINKLOCAL)))
+                       if (!memcmp(gid, &attr->gid, SMC_GID_SIZE))
+                               rc = true;
+               rcu_read_unlock();
+               rdma_put_gid_attr(attr);
+       }
+       return rc;
+}
+
+/* check all links if the gid is still defined on smcibdev */
+static void smc_ib_gid_check(struct smc_ib_device *smcibdev, u8 ibport)
+{
+       struct smc_link_group *lgr;
+       int i;
+
+       spin_lock_bh(&smc_lgr_list.lock);
+       list_for_each_entry(lgr, &smc_lgr_list.list, list) {
+               if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
+                           SMC_MAX_PNETID_LEN))
+                       continue; /* lgr is not affected */
+               if (list_empty(&lgr->list))
+                       continue;
+               for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+                       if (lgr->lnk[i].state == SMC_LNK_UNUSED ||
+                           lgr->lnk[i].smcibdev != smcibdev)
+                               continue;
+                       if (!smc_ib_check_link_gid(lgr->lnk[i].gid,
+                                                  lgr->smc_version == SMC_V2,
+                                                  smcibdev, ibport))
+                               smcr_port_err(smcibdev, ibport);
+               }
+       }
+       spin_unlock_bh(&smc_lgr_list.lock);
+}
+
 static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
 {
        int rc;
@@ -333,6 +385,7 @@ static void smc_ib_port_event_work(struct work_struct *work)
                } else {
                        clear_bit(port_idx, smcibdev->ports_going_away);
                        smcr_port_add(smcibdev, port_idx + 1);
+                       smc_ib_gid_check(smcibdev, port_idx + 1);
                }
        }
 }