@@ -2288,10 +2288,38 @@ static bool seq_sk_match(struct seq_file *seq, const struct sock *sk)
net_eq(sock_net(sk), seq_file_net(seq)));
}
-/*
- * Get next listener socket follow cur. If cur is NULL, get first socket
- * starting from bucket given in st->bucket; when st->bucket is zero the
- * very first socket in the hash table is returned.
+/* Find a non empty bucket (starting from st->bucket)
+ * and return the first sk from it.
+ */
+static void *listening_get_first(struct seq_file *seq)
+{
+ struct tcp_iter_state *st = seq->private;
+
+ st->offset = 0;
+ for (; st->bucket < INET_LHTABLE_SIZE; st->bucket++) {
+ struct inet_listen_hashbucket *ilb;
+ struct hlist_nulls_node *node;
+ struct sock *sk;
+
+ ilb = &tcp_hashinfo.listening_hash[st->bucket];
+ if (hlist_nulls_empty(&ilb->nulls_head))
+ continue;
+
+ spin_lock(&ilb->lock);
+ sk_nulls_for_each(sk, node, &ilb->nulls_head) {
+ if (seq_sk_match(seq, sk))
+ return sk;
+ }
+ spin_unlock(&ilb->lock);
+ }
+
+ return NULL;
+}
+
+/* Find the next sk of "cur" within the same bucket (i.e. st->bucket).
+ * If "cur" is the last one in the st->bucket,
+ * call listening_get_first() to return the first sk of the next
+ * non empty bucket.
*/
static void *listening_get_next(struct seq_file *seq, void *cur)
{
@@ -2300,29 +2328,20 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
struct hlist_nulls_node *node;
struct sock *sk = cur;
- if (!sk) {
-get_head:
- ilb = &tcp_hashinfo.listening_hash[st->bucket];
- spin_lock(&ilb->lock);
- sk = sk_nulls_head(&ilb->nulls_head);
- st->offset = 0;
- goto get_sk;
- }
- ilb = &tcp_hashinfo.listening_hash[st->bucket];
++st->num;
++st->offset;
sk = sk_nulls_next(sk);
-get_sk:
+
sk_nulls_for_each_from(sk, node) {
if (seq_sk_match(seq, sk))
return sk;
}
+
+ ilb = &tcp_hashinfo.listening_hash[st->bucket];
spin_unlock(&ilb->lock);
- st->offset = 0;
- if (++st->bucket < INET_LHTABLE_SIZE)
- goto get_head;
- return NULL;
+ ++st->bucket;
+ return listening_get_first(seq);
}
static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
@@ -2332,7 +2351,7 @@ static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
st->bucket = 0;
st->offset = 0;
- rc = listening_get_next(seq, NULL);
+ rc = listening_get_first(seq);
while (rc && *pos) {
rc = listening_get_next(seq, rc);
@@ -2440,7 +2459,7 @@ static void *tcp_seek_last_pos(struct seq_file *seq)
if (st->bucket >= INET_LHTABLE_SIZE)
break;
st->state = TCP_SEQ_STATE_LISTENING;
- rc = listening_get_next(seq, NULL);
+ rc = listening_get_first(seq);
while (offset-- && rc && bucket == st->bucket)
rc = listening_get_next(seq, rc);
if (rc)
The current listening_get_next() is overloaded by passing NULL to the 2nd arg, like listening_get_next(seq, NULL), to mean get_first(). This patch moves some logic from the listening_get_next() into a new function listening_get_first(). It will be equivalent to the current established_get_first() and established_get_next() setup. get_first() is to find a non empty bucket and return the first sk. get_next() is to find the next sk of the current bucket and then resorts to get_first() if the current bucket is exhausted. The next patch is to move the listener seq_file iteration from listening_hash (port only) to lhash2 (port+addr). Separating out listening_get_first() from listening_get_next() here will make the following lhash2 changes cleaner and easier to follow. Signed-off-by: Martin KaFai Lau <kafai@fb.com> --- net/ipv4/tcp_ipv4.c | 59 ++++++++++++++++++++++++++++++--------------- 1 file changed, 39 insertions(+), 20 deletions(-)