Revert "ipv6: Handle race in addrconf_dad_work"

This reverts commit 967e7b45cfe7cada13f1e784c285688cce4923d1.

Eric reported tests failings with commit. After digging into it,
the bottom line is that the DAD sequence is not to be messed with.
There are too many cases that are expected to proceed regardless
of whether a device is up.

Revert the patch and I will send a different solution for the
problem Rajendra reported.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index dd3be06d5a066e494617d4917c757eae19340d4d..6a576ff92c399fbb686c839c525e700f2579b1a9 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4032,12 +4032,6 @@ static void addrconf_dad_work(struct work_struct *w)
 
        rtnl_lock();
 
-       /* check if device was taken down before this delayed work
-        * function could be canceled
-        */
-       if (idev->dead || !(idev->if_flags & IF_READY))
-               goto out;
-
        spin_lock_bh(&ifp->lock);
        if (ifp->state == INET6_IFADDR_STATE_PREDAD) {
                action = DAD_BEGIN;
@@ -4083,6 +4077,11 @@ static void addrconf_dad_work(struct work_struct *w)
                goto out;
 
        write_lock_bh(&idev->lock);
+       if (idev->dead || !(idev->if_flags & IF_READY)) {
+               write_unlock_bh(&idev->lock);
+               goto out;
+       }
+
        spin_lock(&ifp->lock);
        if (ifp->state == INET6_IFADDR_STATE_DEAD) {
                spin_unlock(&ifp->lock);