tipc: Allow retransmission of cloned buffers

Forward port commit
fc477e160af086f6e30c3d4fdf5f5c000d29beb5
from git://tipc.cslab.ericsson.net/pub/git/people/allan/tipc.git

Origional commit message:

Allow retransmission of cloned buffers

This patch fixes an issue with TIPC's message retransmission logic
that prevented retransmission of clone sk_buffs.  Originally intended
as a means of avoiding wasted work in retransmitting messages that
were still on the driver's outbound queue, it also prevented TIPC
from retransmitting messages through other means -- such as the
secondary bearer of the broadcast link, or another interface in a
set of bonded interfaces.  This fix removes existing checks for
cloned sk_buffs that prevented such retransmission.

Origionally-Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 1a7e466..49f2be8 100644 (file)
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1553,7 +1553,7 @@ u32 tipc_link_push_packet(struct link *l_ptr)
 
        /* Continue retransmission now, if there is anything: */
 
-       if (r_q_size && buf && !skb_cloned(buf)) {
+       if (r_q_size && buf) {
                msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
                msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
                if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
@@ -1722,15 +1722,16 @@ void tipc_link_retransmit(struct link *l_ptr, struct sk_buff *buf,
        dbg("Retransmitting %u in link %x\n", retransmits, l_ptr);
 
        if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
-               if (!skb_cloned(buf)) {
+               if (l_ptr->retransm_queue_size == 0) {
                        msg_dbg(msg, ">NO_RETR->BCONG>");
                        dbg_print_link(l_ptr, "   ");
                        l_ptr->retransm_queue_head = msg_seqno(msg);
                        l_ptr->retransm_queue_size = retransmits;
-                       return;
                } else {
-                       /* Don't retransmit if driver already has the buffer */
+                       err("Unexpected retransmit on link %s (qsize=%d)\n",
+                           l_ptr->name, l_ptr->retransm_queue_size);
                }
+               return;
        } else {
                /* Detect repeated retransmit failures on uncongested bearer */
 
@@ -1745,7 +1746,7 @@ void tipc_link_retransmit(struct link *l_ptr, struct sk_buff *buf,
                }
        }
 
-       while (retransmits && (buf != l_ptr->next_out) && buf && !skb_cloned(buf)) {
+       while (retransmits && (buf != l_ptr->next_out) && buf) {
                msg = buf_msg(buf);
                msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
                msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);