From 8beb9ab6c2df203e8d68cb1f48cf42604a6bed86 Mon Sep 17 00:00:00 2001 From: Octavian Purdila Date: Sat, 26 Dec 2009 11:51:06 +0000 Subject: [PATCH] llc: convert llc_sap_list to RCU Signed-off-by: Octavian Purdila Signed-off-by: David S. Miller --- include/net/llc.h | 2 +- net/llc/llc_core.c | 46 ++++++++++++++-------------------------------- net/llc/llc_proc.c | 11 ++++------- 3 files changed, 19 insertions(+), 40 deletions(-) diff --git a/include/net/llc.h b/include/net/llc.h index 709a9b37e239..5503b74ab170 100644 --- a/include/net/llc.h +++ b/include/net/llc.h @@ -93,7 +93,7 @@ struct hlist_nulls_head *llc_sk_laddr_hash(struct llc_sap *sap, #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 0c9ef8bc7655..78167e81dfeb 100644 --- a/net/llc/llc_core.c +++ b/net/llc/llc_core.c @@ -23,7 +23,7 @@ #include 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 @@ static struct llc_sap *llc_sap_alloc(void) 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 @@ out: */ 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 *llc_sap_open(unsigned char lsap, { 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 @@ struct llc_sap *llc_sap_open(unsigned char lsap, 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 @@ out: 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 09dec6307206..7af1ff2d1f19 100644 --- a/net/llc/llc_proc.c +++ b/net/llc/llc_proc.c @@ -32,14 +32,11 @@ static void llc_ui_format_mac(struct seq_file *seq, u8 *addr) 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 @@ static void *llc_seq_start(struct seq_file *seq, loff_t *pos) { 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 @@ static void *llc_seq_next(struct seq_file *seq, void *v, loff_t *pos) 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 @@ static void llc_seq_stop(struct seq_file *seq, void *v) 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) -- 2.30.2