1 files changed, 62 insertions, 48 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 641f2e47f165..79981d97bc9c 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -115,15 +115,24 @@
 #include <net/checksum.h>
 #include <linux/security.h>
 
-struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
+struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
 EXPORT_SYMBOL_GPL(unix_socket_table);
 DEFINE_SPINLOCK(unix_table_lock);
 EXPORT_SYMBOL_GPL(unix_table_lock);
 static atomic_long_t unix_nr_socks;
 
-#define unix_sockets_unbound	(&unix_socket_table[UNIX_HASH_SIZE])
 
-#define UNIX_ABSTRACT(sk)	(unix_sk(sk)->addr->hash != UNIX_HASH_SIZE)
+static struct hlist_head *unix_sockets_unbound(void *addr)
+{
+	unsigned long hash = (unsigned long)addr;
+
+	hash ^= hash >> 16;
+	hash ^= hash >> 8;
+	hash %= UNIX_HASH_SIZE;
+	return &unix_socket_table[UNIX_HASH_SIZE + hash];
+}
+
+#define UNIX_ABSTRACT(sk)	(unix_sk(sk)->addr->hash < UNIX_HASH_SIZE)
 
 #ifdef CONFIG_SECURITY_NETWORK
 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
@@ -645,7 +654,7 @@ static struct sock *unix_create1(struct net *net, struct socket *sock)
 	INIT_LIST_HEAD(&u->link);
 	mutex_init(&u->readlock); /* single task reading lock */
 	init_waitqueue_head(&u->peer_wait);
-	unix_insert_socket(unix_sockets_unbound, sk);
+	unix_insert_socket(unix_sockets_unbound(sk), sk);
 out:
 	if (sk == NULL)
 		atomic_long_dec(&unix_nr_socks);
@@ -2239,47 +2248,54 @@ static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
 }
 
 #ifdef CONFIG_PROC_FS
-static struct sock *first_unix_socket(int *i)
+
+#define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1)
+
+#define get_bucket(x) ((x) >> BUCKET_SPACE)
+#define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1))
+#define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o))
+
+static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos)
 {
-	for (*i = 0; *i <= UNIX_HASH_SIZE; (*i)++) {
-		if (!hlist_empty(&unix_socket_table[*i]))
-			return __sk_head(&unix_socket_table[*i]);
+	unsigned long offset = get_offset(*pos);
+	unsigned long bucket = get_bucket(*pos);
+	struct sock *sk;
+	unsigned long count = 0;
+
+	for (sk = sk_head(&unix_socket_table[bucket]); sk; sk = sk_next(sk)) {
+		if (sock_net(sk) != seq_file_net(seq))
+			continue;
+		if (++count == offset)
+			break;
 	}
-	return NULL;
+
+	return sk;
 }
 
-static struct sock *next_unix_socket(int *i, struct sock *s)
+static struct sock *unix_next_socket(struct seq_file *seq,
+				     struct sock *sk,
+				     loff_t *pos)
 {
-	struct sock *next = sk_next(s);
-	/* More in this chain? */
-	if (next)
-		return next;
-	/* Look for next non-empty chain. */
-	for ((*i)++; *i <= UNIX_HASH_SIZE; (*i)++) {
-		if (!hlist_empty(&unix_socket_table[*i]))
-			return __sk_head(&unix_socket_table[*i]);
+	unsigned long bucket;
+
+	while (sk > (struct sock *)SEQ_START_TOKEN) {
+		sk = sk_next(sk);
+		if (!sk)
+			goto next_bucket;
+		if (sock_net(sk) == seq_file_net(seq))
+			return sk;
 	}
-	return NULL;
-}
 
-struct unix_iter_state {
-	struct seq_net_private p;
-	int i;
-};
+	do {
+		sk = unix_from_bucket(seq, pos);
+		if (sk)
+			return sk;
 
-static struct sock *unix_seq_idx(struct seq_file *seq, loff_t pos)
-{
-	struct unix_iter_state *iter = seq->private;
-	loff_t off = 0;
-	struct sock *s;
+next_bucket:
+		bucket = get_bucket(*pos) + 1;
+		*pos = set_bucket_offset(bucket, 1);
+	} while (bucket < ARRAY_SIZE(unix_socket_table));
 
-	for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) {
-		if (sock_net(s) != seq_file_net(seq))
-			continue;
-		if (off == pos)
-			return s;
-		++off;
-	}
 	return NULL;
 }
 
@@ -2287,22 +2303,20 @@ static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
 	__acquires(unix_table_lock)
 {
 	spin_lock(&unix_table_lock);
-	return *pos ? unix_seq_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+
+	if (!*pos)
+		return SEQ_START_TOKEN;
+
+	if (get_bucket(*pos) >= ARRAY_SIZE(unix_socket_table))
+		return NULL;
+
+	return unix_next_socket(seq, NULL, pos);
 }
 
 static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-	struct unix_iter_state *iter = seq->private;
-	struct sock *sk = v;
 	++*pos;
-
-	if (v == SEQ_START_TOKEN)
-		sk = first_unix_socket(&iter->i);
-	else
-		sk = next_unix_socket(&iter->i, sk);
-	while (sk && (sock_net(sk) != seq_file_net(seq)))
-		sk = next_unix_socket(&iter->i, sk);
-	return sk;
+	return unix_next_socket(seq, v, pos);
 }
 
 static void unix_seq_stop(struct seq_file *seq, void *v)
@@ -2365,7 +2379,7 @@ static const struct seq_operations unix_seq_ops = {
 static int unix_seq_open(struct inode *inode, struct file *file)
 {
 	return seq_open_net(inode, file, &unix_seq_ops,
-			    sizeof(struct unix_iter_state));
+			    sizeof(struct seq_net_private));
 }
 
 static const struct file_operations unix_seq_fops = {