* [PATCH] bonding: don't call alb_set_slave_mac_addr() while atomic
@ 2013-06-17 17:26 Veaceslav Falico
2013-06-17 17:30 ` Veaceslav Falico
0 siblings, 1 reply; 2+ messages in thread
From: Veaceslav Falico @ 2013-06-17 17:26 UTC (permalink / raw)
To: netdev; +Cc: fubar, andy, vfalico, nikolay
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>
---
drivers/net/bonding/bond_alb.c | 40 +++++-----------------------------------
1 file changed, 5 insertions(+), 35 deletions(-)
diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index a236234..27fe329 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -1175,16 +1175,13 @@ static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *sla
* @slave.
*
* 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.
+ * bond slave list.
*/
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;
}
--
1.8.1.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] bonding: don't call alb_set_slave_mac_addr() while atomic
2013-06-17 17:26 [PATCH] bonding: don't call alb_set_slave_mac_addr() while atomic Veaceslav Falico
@ 2013-06-17 17:30 ` Veaceslav Falico
0 siblings, 0 replies; 2+ messages in thread
From: Veaceslav Falico @ 2013-06-17 17:30 UTC (permalink / raw)
To: netdev; +Cc: fubar, andy
On Mon, Jun 17, 2013 at 07:26:22PM +0200, Veaceslav Falico wrote:
>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>
Self-NAK, sent it by hand, forgot to add one space in the command line.
Will send a new one.
Sorry for the noise.
>---
> drivers/net/bonding/bond_alb.c | 40 +++++-----------------------------------
> 1 file changed, 5 insertions(+), 35 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
>index a236234..27fe329 100644
>--- a/drivers/net/bonding/bond_alb.c
>+++ b/drivers/net/bonding/bond_alb.c
>@@ -1175,16 +1175,13 @@ static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *sla
> * @slave.
> *
> * 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.
>+ * bond slave list.
> */
> 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;
> }
>--
>1.8.1.4
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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