From: Veaceslav Falico <vfalico@redhat•com>
To: netdev@vger•kernel.org
Cc: fubar@us•ibm.com, andy@greyhouse•net
Subject: Re: [PATCH] bonding: don't call alb_set_slave_mac_addr() while atomic
Date: Mon, 17 Jun 2013 19:30:03 +0200 [thread overview]
Message-ID: <20130617173003.GA17707@redhat.com> (raw)
In-Reply-To: <1371489982-4381-1-git-send-email-vfalico@redhat.com>
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
>
prev parent reply other threads:[~2013-06-17 17:30 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
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 [this message]
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