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[tipc-discussion] [net-next v3 1/8] tipc: refactor function tipc_enable_bearer()
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From: Jon M. <jon...@er...> - 2018-03-20 19:25:32
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As a preparation for the next commits we try to reduce the footprint of
the function tipc_enable_bearer(), while hopefully making is simpler to
follow.
Acked-by: Ying Xue <yin...@wi...>
Signed-off-by: Jon Maloy <jon...@er...>
---
net/tipc/bearer.c | 136 ++++++++++++++++++++++++++++--------------------------
1 file changed, 70 insertions(+), 66 deletions(-)
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index f3d2e83..e18cb27 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -230,88 +230,90 @@ void tipc_bearer_remove_dest(struct net *net, u32 bearer_id, u32 dest)
* tipc_enable_bearer - enable bearer with the given name
*/
static int tipc_enable_bearer(struct net *net, const char *name,
- u32 disc_domain, u32 priority,
+ u32 disc_domain, u32 prio,
struct nlattr *attr[])
{
- struct tipc_net *tn = net_generic(net, tipc_net_id);
+ struct tipc_net *tn = tipc_net(net);
+ struct tipc_bearer_names b_names;
+ u32 self = tipc_own_addr(net);
+ int with_this_prio = 1;
struct tipc_bearer *b;
struct tipc_media *m;
- struct tipc_bearer_names b_names;
struct sk_buff *skb;
char addr_string[16];
- u32 bearer_id;
- u32 with_this_prio;
- u32 i;
+ int bearer_id = 0;
int res = -EINVAL;
+ char *errstr = "";
- if (!tn->own_addr) {
- pr_warn("Bearer <%s> rejected, not supported in standalone mode\n",
- name);
- return -ENOPROTOOPT;
+ if (!self) {
+ errstr = "not supported in standalone mode";
+ res = -ENOPROTOOPT;
+ goto rejected;
}
+
if (!bearer_name_validate(name, &b_names)) {
- pr_warn("Bearer <%s> rejected, illegal name\n", name);
- return -EINVAL;
+ errstr = "illegal name";
+ goto rejected;
}
- if (tipc_addr_domain_valid(disc_domain) &&
- (disc_domain != tn->own_addr)) {
- if (tipc_in_scope(disc_domain, tn->own_addr)) {
- disc_domain = tn->own_addr & TIPC_ZONE_CLUSTER_MASK;
- res = 0; /* accept any node in own cluster */
- } else if (in_own_cluster_exact(net, disc_domain))
- res = 0; /* accept specified node in own cluster */
+
+ if (tipc_addr_domain_valid(disc_domain) && disc_domain != self) {
+ if (tipc_in_scope(disc_domain, self)) {
+ /* Accept any node in own cluster */
+ disc_domain = self & TIPC_ZONE_CLUSTER_MASK;
+ res = 0;
+ } else if (in_own_cluster_exact(net, disc_domain)) {
+ /* Accept specified node in own cluster */
+ res = 0;
+ }
}
if (res) {
- pr_warn("Bearer <%s> rejected, illegal discovery domain\n",
- name);
- return -EINVAL;
+ errstr = "illegal discovery domain";
+ goto rejected;
}
- if ((priority > TIPC_MAX_LINK_PRI) &&
- (priority != TIPC_MEDIA_LINK_PRI)) {
- pr_warn("Bearer <%s> rejected, illegal priority\n", name);
- return -EINVAL;
+
+ if (prio > TIPC_MAX_LINK_PRI && prio != TIPC_MEDIA_LINK_PRI) {
+ errstr = "illegal priority";
+ goto rejected;
}
m = tipc_media_find(b_names.media_name);
if (!m) {
- pr_warn("Bearer <%s> rejected, media <%s> not registered\n",
- name, b_names.media_name);
- return -EINVAL;
+ errstr = "media not registered";
+ goto rejected;
}
- if (priority == TIPC_MEDIA_LINK_PRI)
- priority = m->priority;
+ if (prio == TIPC_MEDIA_LINK_PRI)
+ prio = m->priority;
-restart:
- bearer_id = MAX_BEARERS;
- with_this_prio = 1;
- for (i = MAX_BEARERS; i-- != 0; ) {
- b = rtnl_dereference(tn->bearer_list[i]);
- if (!b) {
- bearer_id = i;
- continue;
- }
+ /* Check new bearer vs existing ones and find free bearer id if any */
+ while (bearer_id < MAX_BEARERS) {
+ b = rtnl_dereference(tn->bearer_list[bearer_id]);
+ if (!b)
+ break;
if (!strcmp(name, b->name)) {
- pr_warn("Bearer <%s> rejected, already enabled\n",
- name);
- return -EINVAL;
+ errstr = "already enabled";
+ goto rejected;
}
- if ((b->priority == priority) &&
- (++with_this_prio > 2)) {
- if (priority-- == 0) {
- pr_warn("Bearer <%s> rejected, duplicate priority\n",
- name);
- return -EINVAL;
- }
- pr_warn("Bearer <%s> priority adjustment required %u->%u\n",
- name, priority + 1, priority);
- goto restart;
+ bearer_id++;
+ if (b->priority != prio)
+ continue;
+ if (++with_this_prio <= 2)
+ continue;
+ pr_warn("Bearer <%s>: already 2 bearers with priority %u\n",
+ name, prio);
+ if (prio == TIPC_MIN_LINK_PRI) {
+ errstr = "cannot adjust to lower";
+ goto rejected;
}
+ pr_warn("Bearer <%s>: trying with adjusted priority\n", name);
+ prio--;
+ bearer_id = 0;
+ with_this_prio = 1;
}
+
if (bearer_id >= MAX_BEARERS) {
- pr_warn("Bearer <%s> rejected, bearer limit reached (%u)\n",
- name, MAX_BEARERS);
- return -EINVAL;
+ errstr = "max 3 bearers permitted";
+ goto rejected;
}
b = kzalloc(sizeof(*b), GFP_ATOMIC);
@@ -322,10 +324,9 @@ static int tipc_enable_bearer(struct net *net, const char *name,
b->media = m;
res = m->enable_media(net, b, attr);
if (res) {
- pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
- name, -res);
kfree(b);
- return -EINVAL;
+ errstr = "failed to enable media";
+ goto rejected;
}
b->identity = bearer_id;
@@ -333,15 +334,15 @@ static int tipc_enable_bearer(struct net *net, const char *name,
b->window = m->window;
b->domain = disc_domain;
b->net_plane = bearer_id + 'A';
- b->priority = priority;
+ b->priority = prio;
test_and_set_bit_lock(0, &b->up);
res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
if (res) {
bearer_disable(net, b);
- pr_warn("Bearer <%s> rejected, discovery object creation failed\n",
- name);
- return -EINVAL;
+ kfree(b);
+ errstr = "failed to create discoverer";
+ goto rejected;
}
rcu_assign_pointer(tn->bearer_list[bearer_id], b);
@@ -353,9 +354,12 @@ static int tipc_enable_bearer(struct net *net, const char *name,
return -ENOMEM;
}
- pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n",
- name,
- tipc_addr_string_fill(addr_string, disc_domain), priority);
+ tipc_addr_string_fill(addr_string, disc_domain);
+ pr_info("Enabled bearer <%s>, discovery scope %s, priority %u\n",
+ name, addr_string, prio);
+ return res;
+rejected:
+ pr_warn("Bearer <%s> rejected, %s\n", name, errstr);
return res;
}
--
2.1.4
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