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authorVladimir Oltean <vladimir.oltean@nxp.com>2021-06-21 19:42:18 +0300
committerDavid S. Miller <davem@davemloft.net>2021-06-21 22:50:20 +0300
commit88faba20e2100c1f367133af56612742ad37df08 (patch)
tree54b39a59d69c8c7294bf675f0e91520f27fce15d
parent4e4ab7950044d195f6e3d4dac328f506badb6efa (diff)
downloadlinux-88faba20e2100c1f367133af56612742ad37df08.tar.xz
net: dsa: targeted MTU notifiers should only match on one port
dsa_slave_change_mtu() calls dsa_port_mtu_change() twice: - it sends a cross-chip notifier with the MTU of the CPU port which is used to update the DSA links. - it sends one targeted MTU notifier which is supposed to only match the user port on which we are changing the MTU. The "propagate_upstream" variable is used here to bypass the cross-chip notifier system from switch.c But due to a mistake, the second, targeted notifier matches not only on the user port, but also on the DSA link which is a member of the same switch, if that exists. And because the DSA links of the entire dst were programmed in a previous round to the largest_mtu via a "propagate_upstream == true" notification, then the dsa_port_mtu_change(propagate_upstream == false) call that is immediately upcoming will break the MTU on the one DSA link which is chip-wise local to the dp whose MTU is changing right now. Example given this daisy chain topology: sw0p0 sw0p1 sw0p2 sw0p3 sw0p4 [ cpu ] [ user ] [ user ] [ dsa ] [ user ] [ x ] [ ] [ ] [ x ] [ ] | +---------+ | sw1p0 sw1p1 sw1p2 sw1p3 sw1p4 [ user ] [ user ] [ user ] [ dsa ] [ dsa ] [ ] [ ] [ ] [ ] [ x ] ip link set sw0p1 mtu 9000 ip link set sw1p1 mtu 9000 # at this stage, sw0p1 and sw1p1 can talk # to one another using jumbo frames ip link set sw0p2 mtu 1500 # this programs the sw0p3 DSA link first to # the largest_mtu of 9000, then reprograms it to # 1500 with the "propagate_upstream == false" # notifier, breaking communication between # sw0p1 and sw1p1 To escape from this situation, make the targeted match really match on a single port - the user port, and rename the "propagate_upstream" variable to "targeted_match" to clarify the intention and avoid future issues. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/dsa/dsa_priv.h4
-rw-r--r--net/dsa/port.c4
-rw-r--r--net/dsa/slave.c9
-rw-r--r--net/dsa/switch.c9
4 files changed, 15 insertions, 11 deletions
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index b8b17474b72b..b0811253d101 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -84,7 +84,7 @@ struct dsa_notifier_vlan_info {
/* DSA_NOTIFIER_MTU */
struct dsa_notifier_mtu_info {
- bool propagate_upstream;
+ bool targeted_match;
int sw_index;
int port;
int mtu;
@@ -200,7 +200,7 @@ int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
bool dsa_port_skip_vlan_configuration(struct dsa_port *dp);
int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock);
int dsa_port_mtu_change(struct dsa_port *dp, int new_mtu,
- bool propagate_upstream);
+ bool targeted_match);
int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
u16 vid);
int dsa_port_fdb_del(struct dsa_port *dp, const unsigned char *addr,
diff --git a/net/dsa/port.c b/net/dsa/port.c
index 6379d66a6bb3..5c93f1e1a03d 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -567,11 +567,11 @@ int dsa_port_mrouter(struct dsa_port *dp, bool mrouter,
}
int dsa_port_mtu_change(struct dsa_port *dp, int new_mtu,
- bool propagate_upstream)
+ bool targeted_match)
{
struct dsa_notifier_mtu_info info = {
.sw_index = dp->ds->index,
- .propagate_upstream = propagate_upstream,
+ .targeted_match = targeted_match,
.port = dp->index,
.mtu = new_mtu,
};
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index ac2ca5f75af3..5e668e529575 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1586,14 +1586,15 @@ int dsa_slave_change_mtu(struct net_device *dev, int new_mtu)
goto out_master_failed;
/* We only need to propagate the MTU of the CPU port to
- * upstream switches.
+ * upstream switches, so create a non-targeted notifier which
+ * updates all switches.
*/
- err = dsa_port_mtu_change(cpu_dp, cpu_mtu, true);
+ err = dsa_port_mtu_change(cpu_dp, cpu_mtu, false);
if (err)
goto out_cpu_failed;
}
- err = dsa_port_mtu_change(dp, new_mtu, false);
+ err = dsa_port_mtu_change(dp, new_mtu, true);
if (err)
goto out_port_failed;
@@ -1607,7 +1608,7 @@ out_port_failed:
if (new_master_mtu != old_master_mtu)
dsa_port_mtu_change(cpu_dp, old_master_mtu -
dsa_tag_protocol_overhead(cpu_dp->tag_ops),
- true);
+ false);
out_cpu_failed:
if (new_master_mtu != old_master_mtu)
dev_set_mtu(master, old_master_mtu);
diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index 8b601ced6b45..75f567390a6b 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -52,10 +52,13 @@ static int dsa_switch_ageing_time(struct dsa_switch *ds,
static bool dsa_switch_mtu_match(struct dsa_switch *ds, int port,
struct dsa_notifier_mtu_info *info)
{
- if (ds->index == info->sw_index)
- return (port == info->port) || dsa_is_dsa_port(ds, port);
+ if (ds->index == info->sw_index && port == info->port)
+ return true;
- if (!info->propagate_upstream)
+ /* Do not propagate to other switches in the tree if the notifier was
+ * targeted for a single switch.
+ */
+ if (info->targeted_match)
return false;
if (dsa_is_dsa_port(ds, port) || dsa_is_cpu_port(ds, port))