net/smc: introduce link_idx for link group array

The link_id is the index of the link in the array of the link group.
When a link in the array is reused for a new link, a different unique
link_id should be used, otherwise the index in the array could collide
with the previous link at this array position.
Use a new variable link_idx as array index, and make link_id an
increasing unique id value.

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

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 3bb45c33db221b246ab5c29120354ad90c4dd5fd..d233112ced2acc40980369e2f4e85e49e6383e65 100644 (file)
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -245,8 +245,28 @@ static void smc_lgr_terminate_work(struct work_struct *work)
        __smc_lgr_terminate(lgr, true);
 }
 
-static int smcr_link_init(struct smc_link *lnk, u8 link_id,
-                         struct smc_init_info *ini)
+/* return next unique link id for the lgr */
+static u8 smcr_next_link_id(struct smc_link_group *lgr)
+{
+       u8 link_id;
+       int i;
+
+       while (1) {
+               link_id = ++lgr->next_link_id;
+               if (!link_id)   /* skip zero as link_id */
+                       link_id = ++lgr->next_link_id;
+               for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+                       if (lgr->lnk[i].state != SMC_LNK_INACTIVE &&
+                           lgr->lnk[i].link_id == link_id)
+                               continue;
+               }
+               break;
+       }
+       return link_id;
+}
+
+static int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
+                         u8 link_idx, struct smc_init_info *ini)
 {
        u8 rndvec[3];
        int rc;
@@ -254,7 +274,8 @@ static int smcr_link_init(struct smc_link *lnk, u8 link_id,
        get_device(&ini->ib_dev->ibdev->dev);
        atomic_inc(&ini->ib_dev->lnk_cnt);
        lnk->state = SMC_LNK_ACTIVATING;
-       lnk->link_id = link_id;
+       lnk->link_id = smcr_next_link_id(lgr);
+       lnk->link_idx = link_idx;
        lnk->smcibdev = ini->ib_dev;
        lnk->ibport = ini->ib_port;
        lnk->path_mtu = ini->ib_dev->pattr[ini->ib_port - 1].active_mtu;
@@ -310,6 +331,7 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
        struct list_head *lgr_list;
        struct smc_link *lnk;
        spinlock_t *lgr_lock;
+       u8 link_idx;
        int rc = 0;
        int i;
 
@@ -338,6 +360,7 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
                INIT_LIST_HEAD(&lgr->sndbufs[i]);
                INIT_LIST_HEAD(&lgr->rmbs[i]);
        }
+       lgr->next_link_id = 0;
        smc_lgr_list.num += SMC_LGR_NUM_INCR;
        memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
        INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
@@ -358,8 +381,9 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
                memcpy(lgr->peer_systemid, ini->ib_lcl->id_for_peer,
                       SMC_SYSTEMID_LEN);
 
-               lnk = &lgr->lnk[SMC_SINGLE_LINK];
-               rc = smcr_link_init(lnk, SMC_SINGLE_LINK, ini);
+               link_idx = SMC_SINGLE_LINK;
+               lnk = &lgr->lnk[link_idx];
+               rc = smcr_link_init(lgr, lnk, link_idx, ini);
                if (rc)
                        goto free_lgr;
                lgr_list = &smc_lgr_list.list;

diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 8041db20c7531c209242f774d41c3096b9e43d23..c459b0639bf306fe1c3d9e6b05c06752e8b585cd 100644 (file)
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -115,6 +115,7 @@ struct smc_link {
        u8                      peer_mac[ETH_ALEN];     /* = gid[8:10||13:15] */
        u8                      peer_gid[SMC_GID_SIZE]; /* gid of peer*/
        u8                      link_id;        /* unique # within link group */
+       u8                      link_idx;       /* index in lgr link array */
 
        enum smc_link_state     state;          /* state of link */
        struct workqueue_struct *llc_wq;        /* single thread work queue */
@@ -222,6 +223,7 @@ struct smc_link_group {
                                                /* remote addr/key pairs */
                        DECLARE_BITMAP(rtokens_used_mask, SMC_RMBS_PER_LGR_MAX);
                                                /* used rtoken elements */
+                       u8                      next_link_id;
                };
                struct { /* SMC-D */
                        u64                     peer_gid;