Patch from Stephen Hemminger The following replaces brlock with RCU in the SNAP module. 25-akpm/net/802/psnap.c | 26 ++++++++++++-------------- 1 files changed, 12 insertions(+), 14 deletions(-) diff -puN net/802/psnap.c~brlock-1 net/802/psnap.c --- 25/net/802/psnap.c~brlock-1 Tue Mar 11 16:57:30 2003 +++ 25-akpm/net/802/psnap.c Tue Mar 11 16:57:30 2003 @@ -21,10 +21,10 @@ #include #include #include -#include LIST_HEAD(snap_list); static struct llc_sap *snap_sap; +static spinlock_t snap_lock = SPIN_LOCK_UNLOCKED; /* * Find a snap client by matching the 5 bytes. @@ -34,17 +34,15 @@ static struct datalink_proto *find_snap_ struct list_head *entry; struct datalink_proto *proto = NULL, *p; - if (list_empty(&snap_list)) - goto out; - - list_for_each(entry, &snap_list) { + rcu_read_lock(); + list_for_each_rcu(entry, &snap_list) { p = list_entry(entry, struct datalink_proto, node); if (!memcmp(p->type, desc, 5)) { proto = p; break; } } -out: + rcu_read_unlock(); return proto; } @@ -124,8 +122,7 @@ struct datalink_proto *register_snap_cli { struct datalink_proto *proto = NULL; - br_write_lock_bh(BR_NETPROTO_LOCK); - + spin_lock_bh(&snap_lock); if (find_snap_client(desc)) goto out; @@ -135,10 +132,10 @@ struct datalink_proto *register_snap_cli proto->rcvfunc = rcvfunc; proto->header_length = 5 + 3; /* snap + 802.2 */ proto->request = snap_request; - list_add(&proto->node, &snap_list); + list_add_rcu(&proto->node, &snap_list); } out: - br_write_unlock_bh(BR_NETPROTO_LOCK); + spin_unlock_bh(&snap_lock); return proto; } @@ -147,12 +144,13 @@ out: */ void unregister_snap_client(struct datalink_proto *proto) { - br_write_lock_bh(BR_NETPROTO_LOCK); + static RCU_HEAD(snap_rcu); - list_del(&proto->node); - kfree(proto); + spin_lock_bh(&snap_lock); + list_del_rcu(&proto->node); + spin_unlock_bh(&snap_lock); - br_write_unlock_bh(BR_NETPROTO_LOCK); + call_rcu(&snap_rcu, (void (*)(void *)) kfree, proto); } MODULE_LICENSE("GPL"); _