Ivan Vecera
2017-May-19 17:30 UTC
[Bridge] [PATCH net-next v2] bridge: fix hello and hold timers starting/stopping
Current bridge code incorrectly handles starting/stopping of hello and
hold timers during STP enable/disable.
1. Timers are stopped in br_stp_start() during NO_STP->USER_STP
transition. The timers are already stopped in NO_STP state so
this is confusing no-op.
2. During USER_STP->NO_STP transition the timers are started. This
does not make sense and is confusion because the timer should not be
active in NO_STP state.
Cc: davem at davemloft.net
Cc: sashok at cumulusnetworks.com
Cc: stephen at networkplumber.org
Cc: bridge at lists.linux-foundation.org
Cc: lucien.xin at gmail.com
Cc: nikolay at cumulusnetworks.com
Signed-off-by: Ivan Vecera <cera at cera.cz>
---
net/bridge/br_stp_if.c | 11 -----------
1 file changed, 11 deletions(-)
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index 08341d2aa9c9..a05027027513 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -150,7 +150,6 @@ static int br_stp_call_user(struct net_bridge *br, char
*arg)
static void br_stp_start(struct net_bridge *br)
{
- struct net_bridge_port *p;
int err = -ENOENT;
if (net_eq(dev_net(br->dev), &init_net))
@@ -169,11 +168,6 @@ static void br_stp_start(struct net_bridge *br)
if (!err) {
br->stp_enabled = BR_USER_STP;
br_debug(br, "userspace STP started\n");
-
- /* Stop hello and hold timers */
- del_timer(&br->hello_timer);
- list_for_each_entry(p, &br->port_list, list)
- del_timer(&p->hold_timer);
} else {
br->stp_enabled = BR_KERNEL_STP;
br_debug(br, "using kernel STP\n");
@@ -187,7 +181,6 @@ static void br_stp_start(struct net_bridge *br)
static void br_stp_stop(struct net_bridge *br)
{
- struct net_bridge_port *p;
int err;
if (br->stp_enabled == BR_USER_STP) {
@@ -196,10 +189,6 @@ static void br_stp_stop(struct net_bridge *br)
br_err(br, "failed to stop userspace STP (%d)\n", err);
/* To start timers on any ports left in blocking */
- mod_timer(&br->hello_timer, jiffies + br->hello_time);
- list_for_each_entry(p, &br->port_list, list)
- mod_timer(&p->hold_timer,
- round_jiffies(jiffies + BR_HOLD_TIME));
spin_lock_bh(&br->lock);
br_port_state_selection(br);
spin_unlock_bh(&br->lock);
--
2.13.0
Xin Long
2017-May-19 17:35 UTC
[Bridge] [PATCH net-next v2] bridge: fix hello and hold timers starting/stopping
On Sat, May 20, 2017 at 1:30 AM, Ivan Vecera <cera at cera.cz> wrote:> Current bridge code incorrectly handles starting/stopping of hello and > hold timers during STP enable/disable. > > 1. Timers are stopped in br_stp_start() during NO_STP->USER_STP > transition. The timers are already stopped in NO_STP state so > this is confusing no-op. > > 2. During USER_STP->NO_STP transition the timers are started. This > does not make sense and is confusion because the timer should not be > active in NO_STP state. > > Cc: davem at davemloft.net > Cc: sashok at cumulusnetworks.com > Cc: stephen at networkplumber.org > Cc: bridge at lists.linux-foundation.org > Cc: lucien.xin at gmail.com > Cc: nikolay at cumulusnetworks.com > Signed-off-by: Ivan Vecera <cera at cera.cz>Reviewed-by: Xin Long <lucien.xin at gmail.com>> --- > net/bridge/br_stp_if.c | 11 ----------- > 1 file changed, 11 deletions(-) > > diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c > index 08341d2aa9c9..a05027027513 100644 > --- a/net/bridge/br_stp_if.c > +++ b/net/bridge/br_stp_if.c > @@ -150,7 +150,6 @@ static int br_stp_call_user(struct net_bridge *br, char *arg) > > static void br_stp_start(struct net_bridge *br) > { > - struct net_bridge_port *p; > int err = -ENOENT; > > if (net_eq(dev_net(br->dev), &init_net)) > @@ -169,11 +168,6 @@ static void br_stp_start(struct net_bridge *br) > if (!err) { > br->stp_enabled = BR_USER_STP; > br_debug(br, "userspace STP started\n"); > - > - /* Stop hello and hold timers */ > - del_timer(&br->hello_timer); > - list_for_each_entry(p, &br->port_list, list) > - del_timer(&p->hold_timer); > } else { > br->stp_enabled = BR_KERNEL_STP; > br_debug(br, "using kernel STP\n"); > @@ -187,7 +181,6 @@ static void br_stp_start(struct net_bridge *br) > > static void br_stp_stop(struct net_bridge *br) > { > - struct net_bridge_port *p; > int err; > > if (br->stp_enabled == BR_USER_STP) { > @@ -196,10 +189,6 @@ static void br_stp_stop(struct net_bridge *br) > br_err(br, "failed to stop userspace STP (%d)\n", err); > > /* To start timers on any ports left in blocking */ > - mod_timer(&br->hello_timer, jiffies + br->hello_time); > - list_for_each_entry(p, &br->port_list, list) > - mod_timer(&p->hold_timer, > - round_jiffies(jiffies + BR_HOLD_TIME)); > spin_lock_bh(&br->lock); > br_port_state_selection(br); > spin_unlock_bh(&br->lock); > -- > 2.13.0 >
Nikolay Aleksandrov
2017-May-19 20:12 UTC
[Bridge] [PATCH net-next v2] bridge: fix hello and hold timers starting/stopping
On 5/19/17 8:30 PM, Ivan Vecera wrote:> Current bridge code incorrectly handles starting/stopping of hello and > hold timers during STP enable/disable. > > 1. Timers are stopped in br_stp_start() during NO_STP->USER_STP > transition. The timers are already stopped in NO_STP state so > this is confusing no-op. > > 2. During USER_STP->NO_STP transition the timers are started. This > does not make sense and is confusion because the timer should not be > active in NO_STP state. > > Cc: davem at davemloft.net > Cc: sashok at cumulusnetworks.com > Cc: stephen at networkplumber.org > Cc: bridge at lists.linux-foundation.org > Cc: lucien.xin at gmail.com > Cc: nikolay at cumulusnetworks.com > Signed-off-by: Ivan Vecera <cera at cera.cz> > --- > net/bridge/br_stp_if.c | 11 ----------- > 1 file changed, 11 deletions(-) >LGTM, thanks! Acked-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
Hangbin Liu
2017-May-20 05:57 UTC
[Bridge] [PATCH net-next v2] bridge: fix hello and hold timers starting/stopping
On Fri, May 19, 2017 at 07:30:43PM +0200, Ivan Vecera wrote:> Current bridge code incorrectly handles starting/stopping of hello and > hold timers during STP enable/disable. > > 1. Timers are stopped in br_stp_start() during NO_STP->USER_STP > transition. The timers are already stopped in NO_STP state so > this is confusing no-op.Hi Ivan, Shouldn't we start hello timer in br_stp_start when NO_STP -> BR_KERNEL_STP ?> > 2. During USER_STP->NO_STP transition the timers are started. This > does not make sense and is confusion because the timer should not be > active in NO_STP state.Yes, but what about BR_KERNEL_STP -> NO_STP in function br_stp_stop() ?> > Cc: davem at davemloft.net > Cc: sashok at cumulusnetworks.com > Cc: stephen at networkplumber.org > Cc: bridge at lists.linux-foundation.org > Cc: lucien.xin at gmail.com > Cc: nikolay at cumulusnetworks.com > Signed-off-by: Ivan Vecera <cera at cera.cz> > --- > net/bridge/br_stp_if.c | 11 ----------- > 1 file changed, 11 deletions(-) > > diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c > index 08341d2aa9c9..a05027027513 100644 > --- a/net/bridge/br_stp_if.c > +++ b/net/bridge/br_stp_if.c > @@ -150,7 +150,6 @@ static int br_stp_call_user(struct net_bridge *br, char *arg) > > static void br_stp_start(struct net_bridge *br) > { > - struct net_bridge_port *p; > int err = -ENOENT; > > if (net_eq(dev_net(br->dev), &init_net)) > @@ -169,11 +168,6 @@ static void br_stp_start(struct net_bridge *br) > if (!err) { > br->stp_enabled = BR_USER_STP; > br_debug(br, "userspace STP started\n"); > - > - /* Stop hello and hold timers */ > - del_timer(&br->hello_timer); > - list_for_each_entry(p, &br->port_list, list) > - del_timer(&p->hold_timer);I'm not sure if user space daemon will send bpdu or not? In comment 76b91c32dd86 ("bridge: stp: when using userspace stp stop kernel hello and hold timers"). Nikolay said we should not handle it with BR_USER_STP.> } else { > br->stp_enabled = BR_KERNEL_STP; > br_debug(br, "using kernel STP\n"); > @@ -187,7 +181,6 @@ static void br_stp_start(struct net_bridge *br) > > static void br_stp_stop(struct net_bridge *br) > { > - struct net_bridge_port *p; > int err; > > if (br->stp_enabled == BR_USER_STP) { > @@ -196,10 +189,6 @@ static void br_stp_stop(struct net_bridge *br) > br_err(br, "failed to stop userspace STP (%d)\n", err); > > /* To start timers on any ports left in blocking */ > - mod_timer(&br->hello_timer, jiffies + br->hello_time); > - list_for_each_entry(p, &br->port_list, list) > - mod_timer(&p->hold_timer, > - round_jiffies(jiffies + BR_HOLD_TIME));If we do not del hello_timer. after it expired in br_hello_timer_expired(), Our state is br->dev->flags & IFF_UP and br->stp_enabled == NO_STP, it will call mod_timer(&br->hello_timer, round_jiffies(jiffies + br->hello_time)) and we will keep sending bpdu message even after stp stoped.> spin_lock_bh(&br->lock); > br_port_state_selection(br); > spin_unlock_bh(&br->lock); > --So how about just like diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c index d8ad73b..0198f62 100644 --- a/net/bridge/br_stp_if.c +++ b/net/bridge/br_stp_if.c @@ -183,6 +183,7 @@ static void br_stp_start(struct net_bridge *br) } else { br->stp_enabled = BR_KERNEL_STP; br_debug(br, "using kernel STP\n"); + mod_timer(&br->hello_timer, jiffies + br->hello_time); /* To start timers on any ports left in blocking */ br_port_state_selection(br); @@ -202,7 +203,6 @@ static void br_stp_stop(struct net_bridge *br) br_err(br, "failed to stop userspace STP (%d)\n", err); /* To start timers on any ports left in blocking */ - mod_timer(&br->hello_timer, jiffies + br->hello_time); list_for_each_entry(p, &br->port_list, list) mod_timer(&p->hold_timer, round_jiffies(jiffies + BR_HOLD_TIME)); @@ -211,6 +211,7 @@ static void br_stp_stop(struct net_bridge *br) spin_unlock_bh(&br->lock); } + del_timer_sync(&br->hello_timer); br->stp_enabled = BR_NO_STP; } Thanks Hangbin
Nikolay Aleksandrov
2017-May-20 06:55 UTC
[Bridge] [PATCH net-next v2] bridge: fix hello and hold timers starting/stopping
On 5/20/17 8:57 AM, Hangbin Liu wrote:> On Fri, May 19, 2017 at 07:30:43PM +0200, Ivan Vecera wrote: >> Current bridge code incorrectly handles starting/stopping of hello and >> hold timers during STP enable/disable. >> >> 1. Timers are stopped in br_stp_start() during NO_STP->USER_STP >> transition. The timers are already stopped in NO_STP state so >> this is confusing no-op. > > Hi Ivan, > > Shouldn't we start hello timer in br_stp_start when NO_STP -> BR_KERNEL_STP ?Please see Xin Long's recent -net patch that fixes exactly this issue. It will answer your questions below, too. https://patchwork.ozlabs.org/patch/764685/>> >> 2. During USER_STP->NO_STP transition the timers are started. This >> does not make sense and is confusion because the timer should not be >> active in NO_STP state. > > Yes, but what about BR_KERNEL_STP -> NO_STP in function br_stp_stop() ? >> >> Cc: davem at davemloft.net >> Cc: sashok at cumulusnetworks.com >> Cc: stephen at networkplumber.org >> Cc: bridge at lists.linux-foundation.org >> Cc: lucien.xin at gmail.com >> Cc: nikolay at cumulusnetworks.com >> Signed-off-by: Ivan Vecera <cera at cera.cz> >> --- >> net/bridge/br_stp_if.c | 11 ----------- >> 1 file changed, 11 deletions(-) >> >> diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c >> index 08341d2aa9c9..a05027027513 100644 >> --- a/net/bridge/br_stp_if.c >> +++ b/net/bridge/br_stp_if.c >> @@ -150,7 +150,6 @@ static int br_stp_call_user(struct net_bridge *br, char *arg) >> >> static void br_stp_start(struct net_bridge *br) >> { >> - struct net_bridge_port *p; >> int err = -ENOENT; >> >> if (net_eq(dev_net(br->dev), &init_net)) >> @@ -169,11 +168,6 @@ static void br_stp_start(struct net_bridge *br) >> if (!err) { >> br->stp_enabled = BR_USER_STP; >> br_debug(br, "userspace STP started\n"); >> - >> - /* Stop hello and hold timers */ >> - del_timer(&br->hello_timer); >> - list_for_each_entry(p, &br->port_list, list) >> - del_timer(&p->hold_timer); > > I'm not sure if user space daemon will send bpdu or not? In comment > 76b91c32dd86 ("bridge: stp: when using userspace stp stop kernel hello and > hold timers"). Nikolay said we should not handle it with BR_USER_STP > >> } else { >> br->stp_enabled = BR_KERNEL_STP; >> br_debug(br, "using kernel STP\n"); >> @@ -187,7 +181,6 @@ static void br_stp_start(struct net_bridge *br) >> >> static void br_stp_stop(struct net_bridge *br) >> { >> - struct net_bridge_port *p; >> int err; >> >> if (br->stp_enabled == BR_USER_STP) { >> @@ -196,10 +189,6 @@ static void br_stp_stop(struct net_bridge *br) >> br_err(br, "failed to stop userspace STP (%d)\n", err); >> >> /* To start timers on any ports left in blocking */ >> - mod_timer(&br->hello_timer, jiffies + br->hello_time); >> - list_for_each_entry(p, &br->port_list, list) >> - mod_timer(&p->hold_timer, >> - round_jiffies(jiffies + BR_HOLD_TIME)); > > If we do not del hello_timer. after it expired in br_hello_timer_expired(), > Our state is br->dev->flags & IFF_UP and br->stp_enabled == NO_STP, it will > call mod_timer(&br->hello_timer, round_jiffies(jiffies + br->hello_time)) > and we will keep sending bpdu message even after stp stoped.Again see Xin Long's recent -net patch.> >> spin_lock_bh(&br->lock); >> br_port_state_selection(br); >> spin_unlock_bh(&br->lock); >> -- > > So how about just like > > diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c > index d8ad73b..0198f62 100644 > --- a/net/bridge/br_stp_if.c > +++ b/net/bridge/br_stp_if.c > @@ -183,6 +183,7 @@ static void br_stp_start(struct net_bridge *br) > } else { > br->stp_enabled = BR_KERNEL_STP; > br_debug(br, "using kernel STP\n"); > + mod_timer(&br->hello_timer, jiffies + br->hello_time); > > /* To start timers on any ports left in blocking */ > br_port_state_selection(br); > @@ -202,7 +203,6 @@ static void br_stp_stop(struct net_bridge *br) > br_err(br, "failed to stop userspace STP (%d)\n", err); > > /* To start timers on any ports left in blocking */ > - mod_timer(&br->hello_timer, jiffies + br->hello_time); > list_for_each_entry(p, &br->port_list, list) > mod_timer(&p->hold_timer, > round_jiffies(jiffies + BR_HOLD_TIME)); > @@ -211,6 +211,7 @@ static void br_stp_stop(struct net_bridge *br) > spin_unlock_bh(&br->lock); > } > > + del_timer_sync(&br->hello_timer); > br->stp_enabled = BR_NO_STP; > } > > Thanks > Hangbin >
Ivan Vecera
2017-May-20 07:06 UTC
[Bridge] [PATCH net-next v2] bridge: fix hello and hold timers starting/stopping
2017-05-20 7:57 GMT+02:00 Hangbin Liu <liuhangbin at gmail.com>:> On Fri, May 19, 2017 at 07:30:43PM +0200, Ivan Vecera wrote: >> Current bridge code incorrectly handles starting/stopping of hello and >> hold timers during STP enable/disable. >> >> 1. Timers are stopped in br_stp_start() during NO_STP->USER_STP >> transition. The timers are already stopped in NO_STP state so >> this is confusing no-op. > > Hi Ivan, > > Shouldn't we start hello timer in br_stp_start when NO_STP -> BR_KERNEL_STP ?As Nikolay mentioned, this is fixed by https://patchwork.ozlabs.org/patch/764685/>> >> 2. During USER_STP->NO_STP transition the timers are started. This >> does not make sense and is confusion because the timer should not be >> active in NO_STP state. > > Yes, but what about BR_KERNEL_STP -> NO_STP in function br_stp_stop() ?The timer is lazily stopped by itself in its handler... or not rearmed respectively.>> Cc: davem at davemloft.net >> Cc: sashok at cumulusnetworks.com >> Cc: stephen at networkplumber.org >> Cc: bridge at lists.linux-foundation.org >> Cc: lucien.xin at gmail.com >> Cc: nikolay at cumulusnetworks.com >> Signed-off-by: Ivan Vecera <cera at cera.cz> >> --- >> net/bridge/br_stp_if.c | 11 ----------- >> 1 file changed, 11 deletions(-) >> >> diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c >> index 08341d2aa9c9..a05027027513 100644 >> --- a/net/bridge/br_stp_if.c >> +++ b/net/bridge/br_stp_if.c >> @@ -150,7 +150,6 @@ static int br_stp_call_user(struct net_bridge *br, char *arg) >> >> static void br_stp_start(struct net_bridge *br) >> { >> - struct net_bridge_port *p; >> int err = -ENOENT; >> >> if (net_eq(dev_net(br->dev), &init_net)) >> @@ -169,11 +168,6 @@ static void br_stp_start(struct net_bridge *br) >> if (!err) { >> br->stp_enabled = BR_USER_STP; >> br_debug(br, "userspace STP started\n"); >> - >> - /* Stop hello and hold timers */ >> - del_timer(&br->hello_timer); >> - list_for_each_entry(p, &br->port_list, list) >> - del_timer(&p->hold_timer); > > I'm not sure if user space daemon will send bpdu or not? In comment > 76b91c32dd86 ("bridge: stp: when using userspace stp stop kernel hello and > hold timers"). Nikolay said we should not handle it with BR_USER_STP. > >> } else { >> br->stp_enabled = BR_KERNEL_STP; >> br_debug(br, "using kernel STP\n"); >> @@ -187,7 +181,6 @@ static void br_stp_start(struct net_bridge *br) >> >> static void br_stp_stop(struct net_bridge *br) >> { >> - struct net_bridge_port *p; >> int err; >> >> if (br->stp_enabled == BR_USER_STP) { >> @@ -196,10 +189,6 @@ static void br_stp_stop(struct net_bridge *br) >> br_err(br, "failed to stop userspace STP (%d)\n", err); >> >> /* To start timers on any ports left in blocking */ >> - mod_timer(&br->hello_timer, jiffies + br->hello_time); >> - list_for_each_entry(p, &br->port_list, list) >> - mod_timer(&p->hold_timer, >> - round_jiffies(jiffies + BR_HOLD_TIME)); > > If we do not del hello_timer. after it expired in br_hello_timer_expired(), > Our state is br->dev->flags & IFF_UP and br->stp_enabled == NO_STP, it will > call mod_timer(&br->hello_timer, round_jiffies(jiffies + br->hello_time)) > and we will keep sending bpdu message even after stp stoped. > >> spin_lock_bh(&br->lock); >> br_port_state_selection(br); >> spin_unlock_bh(&br->lock); >> -- > > So how about just like > > diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c > index d8ad73b..0198f62 100644 > --- a/net/bridge/br_stp_if.c > +++ b/net/bridge/br_stp_if.c > @@ -183,6 +183,7 @@ static void br_stp_start(struct net_bridge *br) > } else { > br->stp_enabled = BR_KERNEL_STP; > br_debug(br, "using kernel STP\n"); > + mod_timer(&br->hello_timer, jiffies + br->hello_time); > > /* To start timers on any ports left in blocking */ > br_port_state_selection(br); > @@ -202,7 +203,6 @@ static void br_stp_stop(struct net_bridge *br) > br_err(br, "failed to stop userspace STP (%d)\n", err); > > /* To start timers on any ports left in blocking */ > - mod_timer(&br->hello_timer, jiffies + br->hello_time); > list_for_each_entry(p, &br->port_list, list) > mod_timer(&p->hold_timer, > round_jiffies(jiffies + BR_HOLD_TIME)); > @@ -211,6 +211,7 @@ static void br_stp_stop(struct net_bridge *br) > spin_unlock_bh(&br->lock); > } > > + del_timer_sync(&br->hello_timer); > br->stp_enabled = BR_NO_STP; > } > > Thanks > Hangbin
David Miller
2017-May-22 18:41 UTC
[Bridge] [PATCH net-next v2] bridge: fix hello and hold timers starting/stopping
From: Ivan Vecera <cera at cera.cz> Date: Fri, 19 May 2017 19:30:43 +0200> Current bridge code incorrectly handles starting/stopping of hello and > hold timers during STP enable/disable. > > 1. Timers are stopped in br_stp_start() during NO_STP->USER_STP > transition. The timers are already stopped in NO_STP state so > this is confusing no-op. > > 2. During USER_STP->NO_STP transition the timers are started. This > does not make sense and is confusion because the timer should not be > active in NO_STP state. > > Cc: davem at davemloft.net > Cc: sashok at cumulusnetworks.com > Cc: stephen at networkplumber.org > Cc: bridge at lists.linux-foundation.org > Cc: lucien.xin at gmail.com > Cc: nikolay at cumulusnetworks.com > Signed-off-by: Ivan Vecera <cera at cera.cz>Applied.