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netfilter: ip6_queue: rwlock to spinlock conversion

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Converts queue_lock rwlock to a spinlock.

(readlocked part can be changed by reads of integer values)

One atomic operation instead of four per ipq_enqueue_packet() call.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Eric Dumazet
2010-06-09 16:25:08 +02:00
committed by Patrick McHardy
parent 5756d346c7
commit 144ad2a6c5
1 changed files with 25 additions and 32 deletions
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57
net/ipv6/netfilter/ip6_queue.c
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@@ -43,7 +43,7 @@ typedef int (*ipq_cmpfn)(struct nf_queue_entry *, unsigned long);
static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE; static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT; static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
static DEFINE_RWLOCK(queue_lock); static DEFINE_SPINLOCK(queue_lock);
static int peer_pid __read_mostly; static int peer_pid __read_mostly;
static unsigned int copy_range __read_mostly; static unsigned int copy_range __read_mostly;
static unsigned int queue_total; static unsigned int queue_total;
@@ -73,10 +73,10 @@ __ipq_set_mode(unsigned char mode, unsigned int range)
break; break;
case IPQ_COPY_PACKET: case IPQ_COPY_PACKET:
copy_mode = mode; if (range > 0xFFFF)
range = 0xFFFF;
copy_range = range; copy_range = range;
if (copy_range > 0xFFFF) copy_mode = mode;
copy_range = 0xFFFF;
break; break;
default: default:
@@ -102,7 +102,7 @@ ipq_find_dequeue_entry(unsigned long id)
{ {
struct nf_queue_entry *entry = NULL, *i; struct nf_queue_entry *entry = NULL, *i;
write_lock_bh(&queue_lock); spin_lock_bh(&queue_lock);
list_for_each_entry(i, &queue_list, list) { list_for_each_entry(i, &queue_list, list) {
if ((unsigned long)i == id) { if ((unsigned long)i == id) {
@@ -116,7 +116,7 @@ ipq_find_dequeue_entry(unsigned long id)
queue_total--; queue_total--;
} }
write_unlock_bh(&queue_lock); spin_unlock_bh(&queue_lock);
return entry; return entry;
} }
@@ -137,9 +137,9 @@ __ipq_flush(ipq_cmpfn cmpfn, unsigned long data)
static void static void
ipq_flush(ipq_cmpfn cmpfn, unsigned long data) ipq_flush(ipq_cmpfn cmpfn, unsigned long data)
{ {
write_lock_bh(&queue_lock); spin_lock_bh(&queue_lock);
__ipq_flush(cmpfn, data); __ipq_flush(cmpfn, data);
write_unlock_bh(&queue_lock); spin_unlock_bh(&queue_lock);
} }
static struct sk_buff * static struct sk_buff *
@@ -153,9 +153,7 @@ ipq_build_packet_message(struct nf_queue_entry *entry, int *errp)
struct nlmsghdr *nlh; struct nlmsghdr *nlh;
struct timeval tv; struct timeval tv;
read_lock_bh(&queue_lock); switch (ACCESS_ONCE(copy_mode)) {
switch (copy_mode) {
case IPQ_COPY_META: case IPQ_COPY_META:
case IPQ_COPY_NONE: case IPQ_COPY_NONE:
size = NLMSG_SPACE(sizeof(*pmsg)); size = NLMSG_SPACE(sizeof(*pmsg));
@@ -163,26 +161,21 @@ ipq_build_packet_message(struct nf_queue_entry *entry, int *errp)
case IPQ_COPY_PACKET: case IPQ_COPY_PACKET:
if (entry->skb->ip_summed == CHECKSUM_PARTIAL && if (entry->skb->ip_summed == CHECKSUM_PARTIAL &&
(*errp = skb_checksum_help(entry->skb))) { (*errp = skb_checksum_help(entry->skb)))
read_unlock_bh(&queue_lock);
return NULL; return NULL;
}
if (copy_range == 0 || copy_range > entry->skb->len) data_len = ACCESS_ONCE(copy_range);
if (data_len == 0 || data_len > entry->skb->len)
data_len = entry->skb->len; data_len = entry->skb->len;
else
data_len = copy_range;
size = NLMSG_SPACE(sizeof(*pmsg) + data_len); size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
break; break;
default: default:
*errp = -EINVAL; *errp = -EINVAL;
read_unlock_bh(&queue_lock);
return NULL; return NULL;
} }
read_unlock_bh(&queue_lock);
skb = alloc_skb(size, GFP_ATOMIC); skb = alloc_skb(size, GFP_ATOMIC);
if (!skb) if (!skb)
goto nlmsg_failure; goto nlmsg_failure;
@@ -242,7 +235,7 @@ ipq_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
if (nskb == NULL) if (nskb == NULL)
return status; return status;
write_lock_bh(&queue_lock); spin_lock_bh(&queue_lock);
if (!peer_pid) if (!peer_pid)
goto err_out_free_nskb; goto err_out_free_nskb;
@@ -266,14 +259,14 @@ ipq_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
__ipq_enqueue_entry(entry); __ipq_enqueue_entry(entry);
write_unlock_bh(&queue_lock); spin_unlock_bh(&queue_lock);
return status; return status;
err_out_free_nskb: err_out_free_nskb:
kfree_skb(nskb); kfree_skb(nskb);
err_out_unlock: err_out_unlock:
write_unlock_bh(&queue_lock); spin_unlock_bh(&queue_lock);
return status; return status;
} }
@@ -342,9 +335,9 @@ ipq_set_mode(unsigned char mode, unsigned int range)
{ {
int status; int status;
write_lock_bh(&queue_lock); spin_lock_bh(&queue_lock);
status = __ipq_set_mode(mode, range); status = __ipq_set_mode(mode, range);
write_unlock_bh(&queue_lock); spin_unlock_bh(&queue_lock);
return status; return status;
} }
@@ -441,11 +434,11 @@ __ipq_rcv_skb(struct sk_buff *skb)
if (security_netlink_recv(skb, CAP_NET_ADMIN)) if (security_netlink_recv(skb, CAP_NET_ADMIN))
RCV_SKB_FAIL(-EPERM); RCV_SKB_FAIL(-EPERM);
write_lock_bh(&queue_lock); spin_lock_bh(&queue_lock);
if (peer_pid) { if (peer_pid) {
if (peer_pid != pid) { if (peer_pid != pid) {
write_unlock_bh(&queue_lock); spin_unlock_bh(&queue_lock);
RCV_SKB_FAIL(-EBUSY); RCV_SKB_FAIL(-EBUSY);
} }
} else { } else {
@@ -453,7 +446,7 @@ __ipq_rcv_skb(struct sk_buff *skb)
peer_pid = pid; peer_pid = pid;
} }
write_unlock_bh(&queue_lock); spin_unlock_bh(&queue_lock);
status = ipq_receive_peer(NLMSG_DATA(nlh), type, status = ipq_receive_peer(NLMSG_DATA(nlh), type,
nlmsglen - NLMSG_LENGTH(0)); nlmsglen - NLMSG_LENGTH(0));
@@ -498,10 +491,10 @@ ipq_rcv_nl_event(struct notifier_block *this,
struct netlink_notify *n = ptr; struct netlink_notify *n = ptr;
if (event == NETLINK_URELEASE && n->protocol == NETLINK_IP6_FW) { if (event == NETLINK_URELEASE && n->protocol == NETLINK_IP6_FW) {
write_lock_bh(&queue_lock); spin_lock_bh(&queue_lock);
if ((net_eq(n->net, &init_net)) && (n->pid == peer_pid)) if ((net_eq(n->net, &init_net)) && (n->pid == peer_pid))
__ipq_reset(); __ipq_reset();
write_unlock_bh(&queue_lock); spin_unlock_bh(&queue_lock);
} }
return NOTIFY_DONE; return NOTIFY_DONE;
} }
@@ -528,7 +521,7 @@ static ctl_table ipq_table[] = {
#ifdef CONFIG_PROC_FS #ifdef CONFIG_PROC_FS
static int ip6_queue_show(struct seq_file *m, void *v) static int ip6_queue_show(struct seq_file *m, void *v)
{ {
read_lock_bh(&queue_lock); spin_lock_bh(&queue_lock);
seq_printf(m, seq_printf(m,
"Peer PID : %d\n" "Peer PID : %d\n"
@@ -546,7 +539,7 @@ static int ip6_queue_show(struct seq_file *m, void *v)
queue_dropped, queue_dropped,
queue_user_dropped); queue_user_dropped);
read_unlock_bh(&queue_lock); spin_unlock_bh(&queue_lock);
return 0; return 0;
} }