tipc: convert tipc_bearers array to pointer list

As part of the effort to introduce RCU protection for the bearer
list, we first need to change it to a list of pointers.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index e0feb7e..b4f8c62 100644 (file)
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -668,9 +668,8 @@ void tipc_bcbearer_sort(void)
        memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
 
        for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
-               struct tipc_bearer *b = &tipc_bearers[b_index];
-
-               if (!b->active || !b->nodes.count)
+               struct tipc_bearer *b = bearer_list[b_index];
+               if (!b || !b->active || !b->nodes.count)
                        continue;
 
                if (!bp_temp[b->priority].primary)

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 7f1f95c..7ff98ef 100644 (file)
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -49,7 +49,7 @@ static struct tipc_media * const media_info_array[] = {
        NULL
 };
 
-struct tipc_bearer tipc_bearers[MAX_BEARERS];
+struct tipc_bearer *bearer_list[MAX_BEARERS];
 
 static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down);
 
@@ -177,8 +177,9 @@ struct tipc_bearer *tipc_bearer_find(const char *name)
        struct tipc_bearer *b_ptr;
        u32 i;
 
-       for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) {
-               if (b_ptr->active && (!strcmp(b_ptr->name, name)))
+       for (i = 0; i < MAX_BEARERS; i++) {
+               b_ptr = bearer_list[i];
+               if (b_ptr && b_ptr->active && (!strcmp(b_ptr->name, name)))
                        return b_ptr;
        }
        return NULL;
@@ -200,7 +201,9 @@ struct sk_buff *tipc_bearer_get_names(void)
        read_lock_bh(&tipc_net_lock);
        for (i = 0; media_info_array[i] != NULL; i++) {
                for (j = 0; j < MAX_BEARERS; j++) {
-                       b = &tipc_bearers[j];
+                       b = bearer_list[j];
+                       if (!b)
+                               continue;
                        if (b->active && (b->media == media_info_array[i])) {
                                tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME,
                                                    b->name,
@@ -284,16 +287,17 @@ restart:
        bearer_id = MAX_BEARERS;
        with_this_prio = 1;
        for (i = MAX_BEARERS; i-- != 0; ) {
-               if (!tipc_bearers[i].active) {
+               b_ptr = bearer_list[i];
+               if (!b_ptr || !b_ptr->active) {
                        bearer_id = i;
                        continue;
                }
-               if (!strcmp(name, tipc_bearers[i].name)) {
+               if (!strcmp(name, b_ptr->name)) {
                        pr_warn("Bearer <%s> rejected, already enabled\n",
                                name);
                        goto exit;
                }
-               if ((tipc_bearers[i].priority == priority) &&
+               if ((b_ptr->priority == priority) &&
                    (++with_this_prio > 2)) {
                        if (priority-- == 0) {
                                pr_warn("Bearer <%s> rejected, duplicate priority\n",
@@ -311,7 +315,11 @@ restart:
                goto exit;
        }
 
-       b_ptr = &tipc_bearers[bearer_id];
+       b_ptr = kzalloc(sizeof(*b_ptr), GFP_ATOMIC);
+       if (!b_ptr) {
+               res = -ENOMEM;
+               goto exit;
+       }
        strcpy(b_ptr->name, name);
        b_ptr->media = m_ptr;
        res = m_ptr->enable_media(b_ptr);
@@ -335,6 +343,9 @@ restart:
                        name);
                goto exit;
        }
+
+       bearer_list[bearer_id] = b_ptr;
+
        pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
                name,
                tipc_addr_string_fill(addr_string, disc_domain), priority);
@@ -362,13 +373,22 @@ static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
  */
 static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down)
 {
+       u32 i;
+
        pr_info("Disabling bearer <%s>\n", b_ptr->name);
        b_ptr->media->disable_media(b_ptr);
 
        tipc_link_delete_list(b_ptr->identity, shutting_down);
        if (b_ptr->link_req)
                tipc_disc_delete(b_ptr->link_req);
-       memset(b_ptr, 0, sizeof(struct tipc_bearer));
+
+       for (i = 0; i < MAX_BEARERS; i++) {
+               if (b_ptr == bearer_list[i]) {
+                       bearer_list[i] = NULL;
+                       break;
+               }
+       }
+       kfree(b_ptr);
 }
 
 int tipc_disable_bearer(const char *name)
@@ -603,10 +623,14 @@ void tipc_bearer_cleanup(void)
 
 void tipc_bearer_stop(void)
 {
+       struct tipc_bearer *b_ptr;
        u32 i;
 
        for (i = 0; i < MAX_BEARERS; i++) {
-               if (tipc_bearers[i].active)
-                       bearer_disable(&tipc_bearers[i], true);
+               b_ptr = bearer_list[i];
+               if (b_ptr && b_ptr->active) {
+                       bearer_disable(b_ptr, true);
+                       bearer_list[i] = NULL;
+               }
        }
 }

diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index 425dd81..f4e72ca 100644 (file)
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -150,7 +150,7 @@ struct tipc_bearer_names {
 
 struct tipc_link;
 
-extern struct tipc_bearer tipc_bearers[];
+extern struct tipc_bearer *bearer_list[];
 
 /*
  * TIPC routines available to supported media types