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bonding: don't call alb_set_slave_mac_addr() while atomic

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alb_set_slave_mac_addr() sets the mac address in alb mode via
dev_set_mac_address(), which might sleep. It's called from
alb_handle_addr_collision_on_attach() in atomic context (under
read_lock(bond->lock)), thus triggering a bug.

Fix this by moving the lock inside alb_handle_addr_collision_on_attach().

v1->v2:
As Nikolay Aleksandrov noticed, we can drop the bond->lock completely.
Also, use bond_slave_has_mac(), when possible.

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Veaceslav Falico 2013-06-17 19:30:35 +02:00 • committed by David S. Miller
parent 72bb72b0d9
commit cedb743f3e
1 changed files with 5 additions and 35 deletions
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40
drivers/net/bonding/bond_alb.c
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@ -1175,16 +1175,13 @@ static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *sla
* @slave. * @slave.
* *
* assumption: this function is called before @slave is attached to the * assumption: this function is called before @slave is attached to the
* bond slave list. * bond slave list.
*
* caller must hold the bond lock for write since the mac addresses are compared
* and may be swapped.
*/ */
static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave) static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave)
{ {
struct slave *tmp_slave1, *tmp_slave2, *free_mac_slave; struct slave *tmp_slave1, *free_mac_slave = NULL;
struct slave *has_bond_addr = bond->curr_active_slave; struct slave *has_bond_addr = bond->curr_active_slave;
int i, j, found = 0; int i;
if (bond->slave_cnt == 0) { if (bond->slave_cnt == 0) {
/* this is the first slave */ /* this is the first slave */
@ -1196,15 +1193,7 @@ static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slav
* slaves in the bond. * slaves in the bond.
*/ */
if (!ether_addr_equal_64bits(slave->perm_hwaddr, bond->dev->dev_addr)) { if (!ether_addr_equal_64bits(slave->perm_hwaddr, bond->dev->dev_addr)) {
bond_for_each_slave(bond, tmp_slave1, i) { if (!bond_slave_has_mac(bond, slave->dev->dev_addr))
if (ether_addr_equal_64bits(tmp_slave1->dev->dev_addr,
slave->dev->dev_addr)) {
found = 1;
break;
}
}
if (!found)
return 0; return 0;
/* Try setting slave mac to bond address and fall-through /* Try setting slave mac to bond address and fall-through
@ -1215,19 +1204,8 @@ static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slav
/* The slave's address is equal to the address of the bond. /* The slave's address is equal to the address of the bond.
* Search for a spare address in the bond for this slave. * Search for a spare address in the bond for this slave.
*/ */
free_mac_slave = NULL;
bond_for_each_slave(bond, tmp_slave1, i) { bond_for_each_slave(bond, tmp_slave1, i) {
found = 0; if (!bond_slave_has_mac(bond, tmp_slave1->perm_hwaddr)) {
bond_for_each_slave(bond, tmp_slave2, j) {
if (ether_addr_equal_64bits(tmp_slave1->perm_hwaddr,
tmp_slave2->dev->dev_addr)) {
found = 1;
break;
}
}
if (!found) {
/* no slave has tmp_slave1's perm addr /* no slave has tmp_slave1's perm addr
* as its curr addr * as its curr addr
*/ */
@ -1607,15 +1585,7 @@ int bond_alb_init_slave(struct bonding *bond, struct slave *slave)
return res; return res;
} }
/* caller must hold the bond lock for write since the mac addresses
* are compared and may be swapped.
*/
read_lock(&bond->lock);
res = alb_handle_addr_collision_on_attach(bond, slave); res = alb_handle_addr_collision_on_attach(bond, slave);
read_unlock(&bond->lock);
if (res) { if (res) {
return res; return res;
} }