Re: 2.6.27.18: bnx2/tg3: BUG: "scheduling while atomic" trying toifenslave a second interface to my bond

[Jay Vosburgh <fubar@us.ibm.com>]

Paul Smith <paul@mad-scientist.net> wrote:

>Hi Jay/David/etc.;
>
>This patch is critical for me to properly use mode 6 (balance-alb)
>bonding; I assume it will be needed for others as well.  I haven't
>checked to see if it's still necessary in 2.6.29/2.6.30, but I didn't
>notice it going into the latest 2.6.27.22, released today.
>
>Is this still unofficial?  Is there an official patch on the horizon?

	David, please apply and queue for -stable:

Subject: [PATCH] bonding: fix alb mode locking regression 

	Fix locking issue in alb MAC address management; removed
incorrect locking and replaced with correct locking.  This bug was
introduced in commit:

commit 059fe7a578fba5bbb0fdc0365bfcf6218fa25eb0
Author: Jay Vosburgh <fubar@us.ibm.com>
Date:   Wed Oct 17 17:37:49 2007 -0700

    bonding: Convert locks to _bh, rework alb locking for new locking

	Bug reported by Paul Smith <paul@mad-scientist.net>, who also
tested the fix.

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 553a899..46d312b 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -1706,10 +1706,8 @@ void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave
  * Called with RTNL
  */
 int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
-	__releases(&bond->curr_slave_lock)
-	__releases(&bond->lock)
 	__acquires(&bond->lock)
-	__acquires(&bond->curr_slave_lock)
+	__releases(&bond->lock)
 {
 	struct bonding *bond = netdev_priv(bond_dev);
 	struct sockaddr *sa = addr;
@@ -1745,9 +1743,6 @@ int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
 		}
 	}
 
-	write_unlock_bh(&bond->curr_slave_lock);
-	read_unlock(&bond->lock);
-
 	if (swap_slave) {
 		alb_swap_mac_addr(bond, swap_slave, bond->curr_active_slave);
 		alb_fasten_mac_swap(bond, swap_slave, bond->curr_active_slave);
@@ -1755,16 +1750,15 @@ int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
 		alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr,
 				       bond->alb_info.rlb_enabled);
 
+		read_lock(&bond->lock);
 		alb_send_learning_packets(bond->curr_active_slave, bond_dev->dev_addr);
 		if (bond->alb_info.rlb_enabled) {
 			/* inform clients mac address has changed */
 			rlb_req_update_slave_clients(bond, bond->curr_active_slave);
 		}
+		read_unlock(&bond->lock);
 	}
 
-	read_lock(&bond->lock);
-	write_lock_bh(&bond->curr_slave_lock);
-
 	return 0;
 }