llc: convert llc_sap_list to RCU
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/llc.h b/include/net/llc.h
index 709a9b3..5503b74 100644
--- a/include/net/llc.h
+++ b/include/net/llc.h
@@ -93,7 +93,7 @@
#define LLC_DEST_CONN 2 /* Type 2 goes here */
extern struct list_head llc_sap_list;
-extern rwlock_t llc_sap_list_lock;
+extern spinlock_t llc_sap_list_lock;
extern int llc_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev);
diff --git a/net/llc/llc_core.c b/net/llc/llc_core.c
index 0c9ef8b..78167e8 100644
--- a/net/llc/llc_core.c
+++ b/net/llc/llc_core.c
@@ -23,7 +23,7 @@
#include <net/llc.h>
LIST_HEAD(llc_sap_list);
-DEFINE_RWLOCK(llc_sap_list_lock);
+DEFINE_SPINLOCK(llc_sap_list_lock);
/**
* llc_sap_alloc - allocates and initializes sap.
@@ -46,30 +46,6 @@
return sap;
}
-/**
- * llc_add_sap - add sap to station list
- * @sap: Address of the sap
- *
- * Adds a sap to the LLC's station sap list.
- */
-static void llc_add_sap(struct llc_sap *sap)
-{
- list_add_tail(&sap->node, &llc_sap_list);
-}
-
-/**
- * llc_del_sap - del sap from station list
- * @sap: Address of the sap
- *
- * Removes a sap to the LLC's station sap list.
- */
-static void llc_del_sap(struct llc_sap *sap)
-{
- write_lock_bh(&llc_sap_list_lock);
- list_del(&sap->node);
- write_unlock_bh(&llc_sap_list_lock);
-}
-
static struct llc_sap *__llc_sap_find(unsigned char sap_value)
{
struct llc_sap* sap;
@@ -93,13 +69,13 @@
*/
struct llc_sap *llc_sap_find(unsigned char sap_value)
{
- struct llc_sap* sap;
+ struct llc_sap *sap;
- read_lock_bh(&llc_sap_list_lock);
+ rcu_read_lock_bh();
sap = __llc_sap_find(sap_value);
if (sap)
llc_sap_hold(sap);
- read_unlock_bh(&llc_sap_list_lock);
+ rcu_read_unlock_bh();
return sap;
}
@@ -120,7 +96,7 @@
{
struct llc_sap *sap = NULL;
- write_lock_bh(&llc_sap_list_lock);
+ spin_lock_bh(&llc_sap_list_lock);
if (__llc_sap_find(lsap)) /* SAP already exists */
goto out;
sap = llc_sap_alloc();
@@ -128,9 +104,9 @@
goto out;
sap->laddr.lsap = lsap;
sap->rcv_func = func;
- llc_add_sap(sap);
+ list_add_tail_rcu(&sap->node, &llc_sap_list);
out:
- write_unlock_bh(&llc_sap_list_lock);
+ spin_unlock_bh(&llc_sap_list_lock);
return sap;
}
@@ -146,7 +122,13 @@
void llc_sap_close(struct llc_sap *sap)
{
WARN_ON(sap->sk_count);
- llc_del_sap(sap);
+
+ spin_lock_bh(&llc_sap_list_lock);
+ list_del_rcu(&sap->node);
+ spin_unlock_bh(&llc_sap_list_lock);
+
+ synchronize_rcu();
+
kfree(sap);
}
diff --git a/net/llc/llc_proc.c b/net/llc/llc_proc.c
index 09dec63..7af1ff2 100644
--- a/net/llc/llc_proc.c
+++ b/net/llc/llc_proc.c
@@ -32,14 +32,11 @@
static struct sock *llc_get_sk_idx(loff_t pos)
{
- struct list_head *sap_entry;
struct llc_sap *sap;
struct sock *sk = NULL;
int i;
- list_for_each(sap_entry, &llc_sap_list) {
- sap = list_entry(sap_entry, struct llc_sap, node);
-
+ list_for_each_entry_rcu(sap, &llc_sap_list, node) {
spin_lock_bh(&sap->sk_lock);
for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++) {
struct hlist_nulls_head *head = &sap->sk_laddr_hash[i];
@@ -62,7 +59,7 @@
{
loff_t l = *pos;
- read_lock_bh(&llc_sap_list_lock);
+ rcu_read_lock_bh();
return l ? llc_get_sk_idx(--l) : SEQ_START_TOKEN;
}
@@ -102,7 +99,7 @@
if (sk)
goto out;
spin_unlock_bh(&sap->sk_lock);
- list_for_each_entry_continue(sap, &llc_sap_list, node) {
+ list_for_each_entry_continue_rcu(sap, &llc_sap_list, node) {
spin_lock_bh(&sap->sk_lock);
sk = laddr_hash_next(sap, -1);
if (sk)
@@ -122,7 +119,7 @@
spin_unlock_bh(&sap->sk_lock);
}
- read_unlock_bh(&llc_sap_list_lock);
+ rcu_read_unlock_bh();
}
static int llc_seq_socket_show(struct seq_file *seq, void *v)