| Message ID | 5279E74C.8070403@huawei.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
Hello. On 11/06/2013 09:53 AM, Ding Tianhong wrote: > The bond_3ad_state_machine_handler() is a slow path, it use the bond > lock to protect the bond slave list and slave port, the slave list > could not be protect by bond lock anymore, so I need to use RTNL or > RCU instead of bond lock, but if I remove the bond lock, the > bond_3ad_state_machine_handler() may use the slave port when bond > releasing the slave, it will occur problems. > As the bond_3ad_unbind_slave() only protected by bond lock or RTNL, > so add RCU is not a good solution as it could not protect the slave > port, so RTNL is fit here. > Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> > --- > drivers/net/bonding/bond_3ad.c | 15 +++++++-------- > 1 file changed, 7 insertions(+), 8 deletions(-) > > diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c > index 187b1b7..a4d190e 100644 > --- a/drivers/net/bonding/bond_3ad.c > +++ b/drivers/net/bonding/bond_3ad.c > @@ -2068,18 +2068,19 @@ void bond_3ad_state_machine_handler(struct work_struct *work) [...] > - //check if there are any slaves > if (!bond_has_slaves(bond)) > goto re_arm; > > - // check if agg_select_timer timer after initialize is timed out > + /* check if agg_select_timer timer after initialize is timed out */ > if (BOND_AD_INFO(bond).agg_select_timer && !(--BOND_AD_INFO(bond).agg_select_timer)) { > slave = bond_first_slave(bond); > port = slave ? &(SLAVE_AD_INFO(slave).port) : NULL; > > - // select the active aggregator for the bond > if (port) { > if (!port->slave) { > pr_warning("%s: Warning: bond's first port is uninitialized\n", > @@ -2093,7 +2094,6 @@ void bond_3ad_state_machine_handler(struct work_struct *work) > bond_3ad_set_carrier(bond); > } > > - // for each port run the state machines > bond_for_each_slave(bond, slave, iter) { > port = &(SLAVE_AD_INFO(slave).port); > if (!port->slave) { > @@ -2114,7 +2114,7 @@ void bond_3ad_state_machine_handler(struct work_struct *work) > ad_mux_machine(port); > ad_tx_machine(port); > > - // turn off the BEGIN bit, since we already handled it > + /* turn off the BEGIN bit, since we already handled it */ > if (port->sm_vars & AD_PORT_BEGIN) > port->sm_vars &= ~AD_PORT_BEGIN; > These comment changes are not documented in the changelog and should most probably be in a separate patch. WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2013/11/7 7:50, Sergei Shtylyov wrote: > Hello. > > On 11/06/2013 09:53 AM, Ding Tianhong wrote: > >> The bond_3ad_state_machine_handler() is a slow path, it use the bond >> lock to protect the bond slave list and slave port, the slave list >> could not be protect by bond lock anymore, so I need to use RTNL or >> RCU instead of bond lock, but if I remove the bond lock, the >> bond_3ad_state_machine_handler() may use the slave port when bond >> releasing the slave, it will occur problems. > >> As the bond_3ad_unbind_slave() only protected by bond lock or RTNL, >> so add RCU is not a good solution as it could not protect the slave >> port, so RTNL is fit here. > >> Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> >> --- >> drivers/net/bonding/bond_3ad.c | 15 +++++++-------- >> 1 file changed, 7 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c >> index 187b1b7..a4d190e 100644 >> --- a/drivers/net/bonding/bond_3ad.c >> +++ b/drivers/net/bonding/bond_3ad.c >> @@ -2068,18 +2068,19 @@ void bond_3ad_state_machine_handler(struct work_struct *work) > [...] >> - //check if there are any slaves >> if (!bond_has_slaves(bond)) >> goto re_arm; >> >> - // check if agg_select_timer timer after initialize is timed out >> + /* check if agg_select_timer timer after initialize is timed out */ >> if (BOND_AD_INFO(bond).agg_select_timer && !(--BOND_AD_INFO(bond).agg_select_timer)) { >> slave = bond_first_slave(bond); >> port = slave ? &(SLAVE_AD_INFO(slave).port) : NULL; >> >> - // select the active aggregator for the bond >> if (port) { >> if (!port->slave) { >> pr_warning("%s: Warning: bond's first port is uninitialized\n", >> @@ -2093,7 +2094,6 @@ void bond_3ad_state_machine_handler(struct work_struct *work) >> bond_3ad_set_carrier(bond); >> } >> >> - // for each port run the state machines >> bond_for_each_slave(bond, slave, iter) { >> port = &(SLAVE_AD_INFO(slave).port); >> if (!port->slave) { >> @@ -2114,7 +2114,7 @@ void bond_3ad_state_machine_handler(struct work_struct *work) >> ad_mux_machine(port); >> ad_tx_machine(port); >> >> - // turn off the BEGIN bit, since we already handled it >> + /* turn off the BEGIN bit, since we already handled it */ >> if (port->sm_vars & AD_PORT_BEGIN) >> port->sm_vars &= ~AD_PORT_BEGIN; >> > > These comment changes are not documented in the changelog and should most probably be in a separate patch. > > WBR, Sergei > thanks for your reply, I miss it in the changelog, it is already a big patch set, so I really do not want to add patch any more, I will add it in changelog. Tnanks Ding > > . > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c index 187b1b7..a4d190e 100644 --- a/drivers/net/bonding/bond_3ad.c +++ b/drivers/net/bonding/bond_3ad.c @@ -2068,18 +2068,19 @@ void bond_3ad_state_machine_handler(struct work_struct *work) struct slave *slave; struct port *port; - read_lock(&bond->lock); + if (!rtnl_trylock()) { + queue_delayed_work(bond->wq, &bond->ad_work, ad_delta_in_ticks); + return; + } - //check if there are any slaves if (!bond_has_slaves(bond)) goto re_arm; - // check if agg_select_timer timer after initialize is timed out + /* check if agg_select_timer timer after initialize is timed out */ if (BOND_AD_INFO(bond).agg_select_timer && !(--BOND_AD_INFO(bond).agg_select_timer)) { slave = bond_first_slave(bond); port = slave ? &(SLAVE_AD_INFO(slave).port) : NULL; - // select the active aggregator for the bond if (port) { if (!port->slave) { pr_warning("%s: Warning: bond's first port is uninitialized\n", @@ -2093,7 +2094,6 @@ void bond_3ad_state_machine_handler(struct work_struct *work) bond_3ad_set_carrier(bond); } - // for each port run the state machines bond_for_each_slave(bond, slave, iter) { port = &(SLAVE_AD_INFO(slave).port); if (!port->slave) { @@ -2114,7 +2114,7 @@ void bond_3ad_state_machine_handler(struct work_struct *work) ad_mux_machine(port); ad_tx_machine(port); - // turn off the BEGIN bit, since we already handled it + /* turn off the BEGIN bit, since we already handled it */ if (port->sm_vars & AD_PORT_BEGIN) port->sm_vars &= ~AD_PORT_BEGIN; @@ -2122,9 +2122,8 @@ void bond_3ad_state_machine_handler(struct work_struct *work) } re_arm: + rtnl_unlock(); queue_delayed_work(bond->wq, &bond->ad_work, ad_delta_in_ticks); - - read_unlock(&bond->lock); } /**
The bond_3ad_state_machine_handler() is a slow path, it use the bond lock to protect the bond slave list and slave port, the slave list could not be protect by bond lock anymore, so I need to use RTNL or RCU instead of bond lock, but if I remove the bond lock, the bond_3ad_state_machine_handler() may use the slave port when bond releasing the slave, it will occur problems. As the bond_3ad_unbind_slave() only protected by bond lock or RTNL, so add RCU is not a good solution as it could not protect the slave port, so RTNL is fit here. Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> --- drivers/net/bonding/bond_3ad.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)