From 059fe7a578fba5bbb0fdc0365bfcf6218fa25eb0 Mon Sep 17 00:00:00 2001 From: Jay Vosburgh Date: Wed, 17 Oct 2007 17:37:49 -0700 Subject: [PATCH] bonding: Convert locks to _bh, rework alb locking for new locking Convert locking-related activity to new & improved system. Convert some lock acquisitions to _bh and rework parts of ALB mode, both to avoid deadlocks with workqueue activity. Signed-off-by: Andy Gospodarek Signed-off-by: Jay Vosburgh Signed-off-by: Jeff Garzik --- drivers/net/bonding/bond_alb.c | 69 ++++++++++++++++++++++++++++++++---- drivers/net/bonding/bond_main.c | 78 ++++++++++++++++++++++++++++------------- 2 files changed, 117 insertions(+), 30 deletions(-) diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c index eb320c3..f2e2872 100644 --- a/drivers/net/bonding/bond_alb.c +++ b/drivers/net/bonding/bond_alb.c @@ -959,19 +959,34 @@ static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[], int hw) return 0; } -/* Caller must hold bond lock for write or curr_slave_lock for write*/ +/* + * Swap MAC addresses between two slaves. + * + * Called with RTNL held, and no other locks. + * + */ + static void alb_swap_mac_addr(struct bonding *bond, struct slave *slave1, struct slave *slave2) { - struct slave *disabled_slave = NULL; u8 tmp_mac_addr[ETH_ALEN]; - int slaves_state_differ; - - slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2)); memcpy(tmp_mac_addr, slave1->dev->dev_addr, ETH_ALEN); alb_set_slave_mac_addr(slave1, slave2->dev->dev_addr, bond->alb_info.rlb_enabled); alb_set_slave_mac_addr(slave2, tmp_mac_addr, bond->alb_info.rlb_enabled); +} + +/* + * Send learning packets after MAC address swap. + * + * Called with RTNL and bond->lock held for read. + */ +static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1, + struct slave *slave2) +{ + int slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2)); + struct slave *disabled_slave = NULL; + /* fasten the change in the switch */ if (SLAVE_IS_OK(slave1)) { alb_send_learning_packets(slave1, slave1->dev->dev_addr); @@ -1044,7 +1059,9 @@ static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *sla } if (found) { + /* locking: needs RTNL and nothing else */ alb_swap_mac_addr(bond, slave, tmp_slave); + alb_fasten_mac_swap(bond, slave, tmp_slave); } } } @@ -1571,13 +1588,21 @@ void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char * Set the bond->curr_active_slave to @new_slave and handle * mac address swapping and promiscuity changes as needed. * - * Caller must hold bond curr_slave_lock for write (or bond lock for write) + * If new_slave is NULL, caller must hold curr_slave_lock or + * bond->lock for write. + * + * If new_slave is not NULL, caller must hold RTNL, bond->lock for + * read and curr_slave_lock for write. Processing here may sleep, so + * no other locks may be held. */ void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave) { struct slave *swap_slave; int i; + if (new_slave) + ASSERT_RTNL(); + if (bond->curr_active_slave == new_slave) { return; } @@ -1610,6 +1635,19 @@ void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave } } + /* + * Arrange for swap_slave and new_slave to temporarily be + * ignored so we can mess with their MAC addresses without + * fear of interference from transmit activity. + */ + if (swap_slave) { + tlb_clear_slave(bond, swap_slave, 1); + } + tlb_clear_slave(bond, new_slave, 1); + + write_unlock_bh(&bond->curr_slave_lock); + read_unlock(&bond->lock); + /* curr_active_slave must be set before calling alb_swap_mac_addr */ if (swap_slave) { /* swap mac address */ @@ -1618,11 +1656,23 @@ void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave /* set the new_slave to the bond mac address */ alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr, bond->alb_info.rlb_enabled); + } + + read_lock(&bond->lock); + + if (swap_slave) { + alb_fasten_mac_swap(bond, swap_slave, new_slave); + } else { /* fasten bond mac on new current slave */ alb_send_learning_packets(new_slave, bond->dev->dev_addr); } + + write_lock_bh(&bond->curr_slave_lock); } +/* + * Called with RTNL + */ int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr) { struct bonding *bond = bond_dev->priv; @@ -1659,8 +1709,12 @@ 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); } else { alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr, bond->alb_info.rlb_enabled); @@ -1672,6 +1726,9 @@ int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr) } } + read_lock(&bond->lock); + write_lock_bh(&bond->curr_slave_lock); + return 0; } diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index a357727..15c1f7a 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1590,15 +1590,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev) case BOND_MODE_TLB: case BOND_MODE_ALB: new_slave->state = BOND_STATE_ACTIVE; - if ((!bond->curr_active_slave) && - (new_slave->link != BOND_LINK_DOWN)) { - /* first slave or no active slave yet, and this link - * is OK, so make this interface the active one - */ - bond_change_active_slave(bond, new_slave); - } else { - bond_set_slave_inactive_flags(new_slave); - } + bond_set_slave_inactive_flags(new_slave); break; default: dprintk("This slave is always active in trunk mode\n"); @@ -1754,9 +1746,23 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev) bond_alb_deinit_slave(bond, slave); } - if (oldcurrent == slave) + if (oldcurrent == slave) { + /* + * Note that we hold RTNL over this sequence, so there + * is no concern that another slave add/remove event + * will interfere. + */ + write_unlock_bh(&bond->lock); + read_lock(&bond->lock); + write_lock_bh(&bond->curr_slave_lock); + bond_select_active_slave(bond); + write_unlock_bh(&bond->curr_slave_lock); + read_unlock(&bond->lock); + write_lock_bh(&bond->lock); + } + if (bond->slave_cnt == 0) { bond_set_carrier(bond); @@ -2012,16 +2018,19 @@ static int bond_ioctl_change_active(struct net_device *bond_dev, struct net_devi return -EINVAL; } - write_lock_bh(&bond->lock); + read_lock(&bond->lock); + read_lock(&bond->curr_slave_lock); old_active = bond->curr_active_slave; + read_unlock(&bond->curr_slave_lock); + new_active = bond_get_slave_by_dev(bond, slave_dev); /* * Changing to the current active: do nothing; return success. */ if (new_active && (new_active == old_active)) { - write_unlock_bh(&bond->lock); + read_unlock(&bond->lock); return 0; } @@ -2029,12 +2038,14 @@ static int bond_ioctl_change_active(struct net_device *bond_dev, struct net_devi (old_active) && (new_active->link == BOND_LINK_UP) && IS_UP(new_active->dev)) { + write_lock_bh(&bond->curr_slave_lock); bond_change_active_slave(bond, new_active); + write_unlock_bh(&bond->curr_slave_lock); } else { res = -EINVAL; } - write_unlock_bh(&bond->lock); + read_unlock(&bond->lock); return res; } @@ -2140,7 +2151,11 @@ static int __bond_mii_monitor(struct bonding *bond, int have_locks) switch (slave->link) { case BOND_LINK_UP: /* the link was up */ if (link_state == BMSR_LSTATUS) { - /* link stays up, nothing more to do */ + if (!oldcurrent) { + if (!have_locks) + return 1; + do_failover = 1; + } break; } else { /* link going down */ slave->link = BOND_LINK_FAIL; @@ -2327,11 +2342,14 @@ static int __bond_mii_monitor(struct bonding *bond, int have_locks) } /* end of for */ if (do_failover) { - write_lock(&bond->curr_slave_lock); + ASSERT_RTNL(); + + write_lock_bh(&bond->curr_slave_lock); bond_select_active_slave(bond); - write_unlock(&bond->curr_slave_lock); + write_unlock_bh(&bond->curr_slave_lock); + } else bond_set_carrier(bond); @@ -2770,11 +2788,14 @@ void bond_loadbalance_arp_mon(struct work_struct *work) } if (do_failover) { - write_lock(&bond->curr_slave_lock); + rtnl_lock(); + write_lock_bh(&bond->curr_slave_lock); bond_select_active_slave(bond); - write_unlock(&bond->curr_slave_lock); + write_unlock_bh(&bond->curr_slave_lock); + rtnl_unlock(); + } re_arm: @@ -2831,7 +2852,9 @@ void bond_activebackup_arp_mon(struct work_struct *work) slave->link = BOND_LINK_UP; - write_lock(&bond->curr_slave_lock); + rtnl_lock(); + + write_lock_bh(&bond->curr_slave_lock); if ((!bond->curr_active_slave) && ((jiffies - slave->dev->trans_start) <= delta_in_ticks)) { @@ -2865,7 +2888,8 @@ void bond_activebackup_arp_mon(struct work_struct *work) slave->dev->name); } - write_unlock(&bond->curr_slave_lock); + write_unlock_bh(&bond->curr_slave_lock); + rtnl_unlock(); } } else { read_lock(&bond->curr_slave_lock); @@ -2935,12 +2959,15 @@ void bond_activebackup_arp_mon(struct work_struct *work) bond->dev->name, slave->dev->name); - write_lock(&bond->curr_slave_lock); + rtnl_lock(); + write_lock_bh(&bond->curr_slave_lock); bond_select_active_slave(bond); slave = bond->curr_active_slave; - write_unlock(&bond->curr_slave_lock); + write_unlock_bh(&bond->curr_slave_lock); + + rtnl_unlock(); bond->current_arp_slave = slave; @@ -2959,9 +2986,12 @@ void bond_activebackup_arp_mon(struct work_struct *work) bond->primary_slave->dev->name); /* primary is up so switch to it */ - write_lock(&bond->curr_slave_lock); + rtnl_lock(); + write_lock_bh(&bond->curr_slave_lock); bond_change_active_slave(bond, bond->primary_slave); - write_unlock(&bond->curr_slave_lock); + write_unlock_bh(&bond->curr_slave_lock); + + rtnl_unlock(); slave = bond->primary_slave; slave->jiffies = jiffies; -- 2.7.4