Calls to rtnl_dump_ifinfo() are protected by RTNL lock. So are the
{list,unlist}_netdevice() calls where we bump the net->dev_base_seq
number.
For this reason net->dev_base_seq can't change under out feet while
we're looping over links in rtnl_dump_ifinfo(). So move the check for
net->dev_base_seq change (since the last time we were called) out of the
loop.
This way we avoid giving a wrong impression that there are concurrent
updates to the link list going on while we're iterating over them.
Signed-off-by: Jakub Sitnicki <j...@redhat.com>
---
net/core/rtnetlink.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 9201e36..6b7888e 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1644,8 +1644,6 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct
netlink_callback *cb)
s_h = cb->args[0];
s_idx = cb->args[1];
- cb->seq = net->dev_base_seq;
-
/* A hack to preserve kernel<->userspace interface.
* The correct header is ifinfomsg. It is consistent with rtnl_getlink.
* However, before Linux v3.9 the code here assumed rtgenmsg and that's
@@ -1691,8 +1689,6 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct
netlink_callback *cb)
goto out_err;
}
-
- nl_dump_check_consistent(cb, nlmsg_hdr(skb));
cont:
idx++;
}
@@ -1702,6 +1698,8 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct
netlink_callback *cb)
out_err:
cb->args[1] = idx;
cb->args[0] = h;
+ cb->seq = net->dev_base_seq;
+ nl_dump_check_consistent(cb, nlmsg_hdr(skb));
return err;
}
--
2.9.4
