RDS: Track transports via an array, not a list
Now that transports can be loaded in arbitrary order,
it is important for rds_trans_get_preferred() to look
for them in a particular order, instead of walking the list
until it finds a transport that works for a given address.
Now, each transport registers for a specific transport slot,
and these are ordered so that preferred transports come first,
and then if they are not loaded, other transports are queried.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/transport.c b/net/rds/transport.c
index 56a5309..7e10679 100644
--- a/net/rds/transport.c
+++ b/net/rds/transport.c
@@ -37,7 +37,7 @@
#include "rds.h"
#include "loop.h"
-static LIST_HEAD(rds_transports);
+static struct rds_transport *transports[RDS_TRANS_COUNT];
static DECLARE_RWSEM(rds_trans_sem);
int rds_trans_register(struct rds_transport *trans)
@@ -46,8 +46,13 @@
down_write(&rds_trans_sem);
- list_add_tail(&trans->t_item, &rds_transports);
- printk(KERN_INFO "Registered RDS/%s transport\n", trans->t_name);
+ if (transports[trans->t_type])
+ printk(KERN_ERR "RDS Transport type %d already registered\n",
+ trans->t_type);
+ else {
+ transports[trans->t_type] = trans;
+ printk(KERN_INFO "Registered RDS/%s transport\n", trans->t_name);
+ }
up_write(&rds_trans_sem);
@@ -59,7 +64,7 @@
{
down_write(&rds_trans_sem);
- list_del_init(&trans->t_item);
+ transports[trans->t_type] = NULL;
printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name);
up_write(&rds_trans_sem);
@@ -68,16 +73,17 @@
struct rds_transport *rds_trans_get_preferred(__be32 addr)
{
- struct rds_transport *trans;
struct rds_transport *ret = NULL;
+ int i;
if (IN_LOOPBACK(ntohl(addr)))
return &rds_loop_transport;
down_read(&rds_trans_sem);
- list_for_each_entry(trans, &rds_transports, t_item) {
- if (trans->laddr_check(addr) == 0) {
- ret = trans;
+ for (i = 0; i < RDS_TRANS_COUNT; i++)
+ {
+ if (transports[i] && (transports[i]->laddr_check(addr) == 0)) {
+ ret = transports[i];
break;
}
}
@@ -99,12 +105,15 @@
struct rds_transport *trans;
unsigned int total = 0;
unsigned int part;
+ int i;
rds_info_iter_unmap(iter);
down_read(&rds_trans_sem);
- list_for_each_entry(trans, &rds_transports, t_item) {
- if (trans->stats_info_copy == NULL)
+ for (i = 0; i < RDS_TRANS_COUNT; i++)
+ {
+ trans = transports[i];
+ if (!trans || !trans->stats_info_copy)
continue;
part = trans->stats_info_copy(iter, avail);