Merge branch 'mlxsw-extack'

David Ahern says:

====================
mlxsw: spectrum_router: Add extack messages for RIF and VRF overflow

Currently, exceeding the number of VRF instances or the number of router
interfaces either fails with a non-intuitive EBUSY:
    $ ip li set swp1s1.6 vrf vrf-1s1-6 up
    RTNETLINK answers: Device or resource busy

or fails silently (IPv6) since the checks are done in a work queue. This
set adds support for the address validator notifier to spectrum which
allows ext-ack based messages to be returned on failure.

To make that happen the IPv6 version needs to be converted from atomic
to blocking (patch 2), and then support for extack needs to be added
to the notifier (patch 3). Patch 1 reworks the locking in ipv6_add_addr
to work better in the atomic and non-atomic code paths. Patches 4 and 5
add the validator notifier to spectrum and then plumb the extack argument
through spectrum_router.

With this set, VRF overflows fail with:
   $ ip li set swp1s1.6 vrf vrf-1s1-6 up
   Error: spectrum: Exceeded number of supported VRF.

and RIF overflows fail with:
   $ ip addr add dev swp1s2.191 10.12.191.1/24
   Error: spectrum: Exceeded number of supported router interfaces.

v2 -> v3
- fix surround context of patch 4 which was altered by c30f5d012edf

v1 -> v2
- fix error path in ipv6_add_addr: reset rt to NULL (Ido comment) and
  add in6_dev_put on ifa once the hold has been done

RFC -> v1
- addressed various comments from Ido
- refactored ipv6_add_addr to allow ifa's to be allocated with
  GFP_KERNEL as requested by DaveM
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 3cf67db513e2..f0ab55df57f1 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -808,10 +808,6 @@ static int ipvlan_addr6_event(struct notifier_block *unused,
         struct net_device *dev = (struct net_device *)if6->idev->dev;
         struct ipvl_dev *ipvlan = netdev_priv(dev);
 
-        /* FIXME IPv6 autoconf calls us from bh without RTNL */
-        if (in_softirq())
-                return NOTIFY_DONE;
-
         if (!netif_is_ipvlan(dev))
                 return NOTIFY_DONE;
 
@@ -851,8 +847,11 @@ static int ipvlan_addr6_validator_event(struct notifier_block *unused,
 
         switch (event) {
         case NETDEV_UP:
-                if (ipvlan_addr_busy(ipvlan->port, &i6vi->i6vi_addr, true))
+                if (ipvlan_addr_busy(ipvlan->port, &i6vi->i6vi_addr, true)) {
+                        NL_SET_ERR_MSG(i6vi->extack,
+                                       "Address already assigned to an ipvlan device");
                         return notifier_from_errno(-EADDRINUSE);
+                }
                 break;
         }
 
@@ -921,8 +920,11 @@ static int ipvlan_addr4_validator_event(struct notifier_block *unused,
 
         switch (event) {
         case NETDEV_UP:
-                if (ipvlan_addr_busy(ipvlan->port, &ivi->ivi_addr, false))
+                if (ipvlan_addr_busy(ipvlan->port, &ivi->ivi_addr, false)) {
+                        NL_SET_ERR_MSG(ivi->extack,
+                                       "Address already assigned to an ipvlan device");
                         return notifier_from_errno(-EADDRINUSE);
+                }
                 break;
         }