RDMA/cma: Increment port number after close to avoid re-use
Randomize the starting port number and avoid re-using port values
immediately after they are closed. Instead keep track of the last
port value used and increment it every time a new port number is
assigned, to better replicate other port spaces.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 9e0ab04..bc31b54 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -71,6 +71,7 @@
static DEFINE_IDR(sdp_ps);
static DEFINE_IDR(tcp_ps);
static DEFINE_IDR(udp_ps);
+static int next_port;
struct cma_device {
struct list_head list;
@@ -1722,33 +1723,74 @@
unsigned short snum)
{
struct rdma_bind_list *bind_list;
- int port, start, ret;
+ int port, ret;
bind_list = kzalloc(sizeof *bind_list, GFP_KERNEL);
if (!bind_list)
return -ENOMEM;
- start = snum ? snum : sysctl_local_port_range[0];
-
do {
- ret = idr_get_new_above(ps, bind_list, start, &port);
+ ret = idr_get_new_above(ps, bind_list, snum, &port);
} while ((ret == -EAGAIN) && idr_pre_get(ps, GFP_KERNEL));
if (ret)
- goto err;
+ goto err1;
- if ((snum && port != snum) ||
- (!snum && port > sysctl_local_port_range[1])) {
- idr_remove(ps, port);
+ if (port != snum) {
ret = -EADDRNOTAVAIL;
- goto err;
+ goto err2;
}
bind_list->ps = ps;
bind_list->port = (unsigned short) port;
cma_bind_port(bind_list, id_priv);
return 0;
-err:
+err2:
+ idr_remove(ps, port);
+err1:
+ kfree(bind_list);
+ return ret;
+}
+
+static int cma_alloc_any_port(struct idr *ps, struct rdma_id_private *id_priv)
+{
+ struct rdma_bind_list *bind_list;
+ int port, ret;
+
+ bind_list = kzalloc(sizeof *bind_list, GFP_KERNEL);
+ if (!bind_list)
+ return -ENOMEM;
+
+retry:
+ do {
+ ret = idr_get_new_above(ps, bind_list, next_port, &port);
+ } while ((ret == -EAGAIN) && idr_pre_get(ps, GFP_KERNEL));
+
+ if (ret)
+ goto err1;
+
+ if (port > sysctl_local_port_range[1]) {
+ if (next_port != sysctl_local_port_range[0]) {
+ idr_remove(ps, port);
+ next_port = sysctl_local_port_range[0];
+ goto retry;
+ }
+ ret = -EADDRNOTAVAIL;
+ goto err2;
+ }
+
+ if (port == sysctl_local_port_range[1])
+ next_port = sysctl_local_port_range[0];
+ else
+ next_port = port + 1;
+
+ bind_list->ps = ps;
+ bind_list->port = (unsigned short) port;
+ cma_bind_port(bind_list, id_priv);
+ return 0;
+err2:
+ idr_remove(ps, port);
+err1:
kfree(bind_list);
return ret;
}
@@ -1811,7 +1853,7 @@
mutex_lock(&lock);
if (cma_any_port(&id_priv->id.route.addr.src_addr))
- ret = cma_alloc_port(ps, id_priv, 0);
+ ret = cma_alloc_any_port(ps, id_priv);
else
ret = cma_use_port(ps, id_priv);
mutex_unlock(&lock);
@@ -2448,6 +2490,10 @@
{
int ret;
+ get_random_bytes(&next_port, sizeof next_port);
+ next_port = (next_port % (sysctl_local_port_range[1] -
+ sysctl_local_port_range[0])) +
+ sysctl_local_port_range[0];
cma_wq = create_singlethread_workqueue("rdma_cm_wq");
if (!cma_wq)
return -ENOMEM;
