提交 16d79d7d 编写于 作者: N Nils Carlson 提交者: David S. Miller

bonding 802.3ad: Fix the state machine locking v2

Changes since v1:
* Clarify an unclear comment
* Move a (possible) name change to a separate patch

The ad_rx_machine, ad_periodic_machine and ad_port_selection_logic
functions all inspect and alter common fields within the port structure.
Previous to this patch, only the ad_rx_machines were mutexed, and the
periodic and port_selection could run unmutexed against an ad_rx_machine
trigged by an arriving LACPDU.

This patch remedies the situation by protecting all the state machines
from concurrency. This is accomplished by locking around all the state
machines for a given port, which are executed at regular intervals; and
the ad_rx_machine when handling an incoming LACPDU.
Signed-off-by: NNils Carlson <nils.carlson@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
上级 ce3c8692
......@@ -1025,9 +1025,6 @@ static void ad_rx_machine(struct lacpdu *lacpdu, struct port *port)
{
rx_states_t last_state;
// Lock to prevent 2 instances of this function to run simultaneously(rx interrupt and periodic machine callback)
__get_rx_machine_lock(port);
// keep current State Machine state to compare later if it was changed
last_state = port->sm_rx_state;
......@@ -1133,7 +1130,6 @@ static void ad_rx_machine(struct lacpdu *lacpdu, struct port *port)
pr_err("%s: An illegal loopback occurred on adapter (%s).\n"
"Check the configuration to verify that all adapters are connected to 802.3ad compliant switch ports\n",
port->slave->dev->master->name, port->slave->dev->name);
__release_rx_machine_lock(port);
return;
}
__update_selected(lacpdu, port);
......@@ -1153,7 +1149,6 @@ static void ad_rx_machine(struct lacpdu *lacpdu, struct port *port)
break;
}
}
__release_rx_machine_lock(port);
}
/**
......@@ -2155,6 +2150,12 @@ void bond_3ad_state_machine_handler(struct work_struct *work)
goto re_arm;
}
/* Lock around state machines to protect data accessed
* by all (e.g., port->sm_vars). ad_rx_machine may run
* concurrently due to incoming LACPDU.
*/
__get_rx_machine_lock(port);
ad_rx_machine(NULL, port);
ad_periodic_machine(port);
ad_port_selection_logic(port);
......@@ -2164,6 +2165,8 @@ void bond_3ad_state_machine_handler(struct work_struct *work)
// turn off the BEGIN bit, since we already handled it
if (port->sm_vars & AD_PORT_BEGIN)
port->sm_vars &= ~AD_PORT_BEGIN;
__release_rx_machine_lock(port);
}
re_arm:
......@@ -2200,7 +2203,10 @@ static void bond_3ad_rx_indication(struct lacpdu *lacpdu, struct slave *slave, u
case AD_TYPE_LACPDU:
pr_debug("Received LACPDU on port %d\n",
port->actor_port_number);
/* Protect against concurrent state machines */
__get_rx_machine_lock(port);
ad_rx_machine(lacpdu, port);
__release_rx_machine_lock(port);
break;
case AD_TYPE_MARKER:
......
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