Signed-off-by: Ken-ichirou MATSUZAWA <cha...@h4.dion.ne.jp>
---
net/netlink/af_netlink.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7e1610e..8901acd 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -576,16 +576,6 @@ netlink_current_frame(const struct netlink_ring *ring,
return netlink_lookup_frame(ring, ring->head, status);
}
-static struct nl_mmap_hdr *
-netlink_previous_frame(const struct netlink_ring *ring,
- enum nl_mmap_status status)
-{
- unsigned int prev;
-
- prev = ring->head ? ring->head - 1 : ring->frame_max;
- return netlink_lookup_frame(ring, prev, status);
-}
-
static void netlink_increment_head(struct netlink_ring *ring)
{
ring->head = ring->head != ring->frame_max ? ring->head + 1 : 0;
@@ -606,6 +596,21 @@ static void netlink_forward_ring(struct netlink_ring *ring)
} while (ring->head != head);
}
+static bool netlink_has_valid_frame(struct netlink_ring *ring)
+{
+ unsigned int head = ring->head, pos = head;
+ const struct nl_mmap_hdr *hdr;
+
+ do {
+ hdr = __netlink_lookup_frame(ring, pos);
+ if (hdr->nm_status == NL_MMAP_STATUS_VALID)
+ return true;
+ pos = pos != ring->frame_max ? pos + 1 : 0;
+ } while (pos != head);
+
+ return false;
+}
+
static bool netlink_dump_space(struct netlink_sock *nlk)
{
struct netlink_ring *ring = &nlk->rx_ring;
@@ -653,8 +658,7 @@ static unsigned int netlink_poll(struct file *file, struct
socket *sock,
spin_lock_bh(&sk->sk_receive_queue.lock);
if (nlk->rx_ring.pg_vec) {
- netlink_forward_ring(&nlk->rx_ring);
- if (!netlink_previous_frame(&nlk->rx_ring,
NL_MMAP_STATUS_UNUSED))
+ if (netlink_has_valid_frame(&nlk->rx_ring))
mask |= POLLIN | POLLRDNORM;
}
spin_unlock_bh(&sk->sk_receive_queue.lock);
--
1.7.10.4
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