Commit cedb743f authored by Veaceslav Falico's avatar Veaceslav Falico Committed by David S. Miller
Browse files

bonding: don't call alb_set_slave_mac_addr() while atomic 



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: default avatarVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: default avatarNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 72bb72b0

drivers/net/bonding/bond_alb.c

+5 −35
Original line number Diff line number Diff line
@@ -1176,15 +1176,12 @@ static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *sla 
 *

 * assumption: this function is called before @slave is attached to the

 *	       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)

{

	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;

	int i, j, found = 0;

	int i;



	if (bond->slave_cnt == 0) {

		/* 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.

	 */

	if (!ether_addr_equal_64bits(slave->perm_hwaddr, bond->dev->dev_addr)) {

		bond_for_each_slave(bond, tmp_slave1, i) {

			if (ether_addr_equal_64bits(tmp_slave1->dev->dev_addr,

						    slave->dev->dev_addr)) {

				found = 1;

				break;

			}

		}



		if (!found)

		if (!bond_slave_has_mac(bond, slave->dev->dev_addr))

			return 0;



		/* 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.

	 * Search for a spare address in the bond for this slave.

	 */

	free_mac_slave = NULL;



	bond_for_each_slave(bond, tmp_slave1, i) {

		found = 0;

		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) {

		if (!bond_slave_has_mac(bond, tmp_slave1->perm_hwaddr)) {

			/* no slave has tmp_slave1's perm addr

			 * as its curr addr

			 */
@@ -1607,15 +1585,7 @@ int bond_alb_init_slave(struct bonding *bond, struct slave *slave) 
		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);



	read_unlock(&bond->lock);



	if (res) {

		return res;

	}

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