From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jay Vosburgh Subject: Re: [PATCH net-next 3/3] bonding: fix bond_release_all inconsistencies Date: Mon, 18 Feb 2013 13:56:48 -0800 Message-ID: <21474.1361224608@death.nxdomain> References: <1361210344-14907-1-git-send-email-nikolay@redhat.com> <1361210344-14907-3-git-send-email-nikolay@redhat.com> Cc: netdev@vger.kernel.org, davem@davemloft.net, andy@greyhouse.net To: Nikolay Aleksandrov Return-path: Received: from e9.ny.us.ibm.com ([32.97.182.139]:58263 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756461Ab3BRV4y (ORCPT ); Mon, 18 Feb 2013 16:56:54 -0500 Received: from /spool/local by e9.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 18 Feb 2013 16:56:53 -0500 Received: from d01relay01.pok.ibm.com (d01relay01.pok.ibm.com [9.56.227.233]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 71F2538C8022 for ; Mon, 18 Feb 2013 16:56:50 -0500 (EST) Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay01.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r1ILuo1x271790 for ; Mon, 18 Feb 2013 16:56:50 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r1ILunHv028335 for ; Mon, 18 Feb 2013 18:56:49 -0300 In-reply-to: <1361210344-14907-3-git-send-email-nikolay@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: Nikolay Aleksandrov wrote: >This patch fixes the following inconsistencies in bond_release_all: >- IFF_BONDING flag is not stripped from slaves >- MTU is not restored >- no netdev notifiers are sent >Instead of trying to keep bond_release and bond_release_all in sync >I think we can re-use bond_release as the environment for calling it >is correct (RTNL is held). I have been running tests for the past >week and they came out successful. The only way for bond_release to fail >is for the slave to be attached in a different bond or to not be a slave >but that cannot happen as RTNL is held and no slave manipulations can be >achieved. It might be worthwhile to add an "all" argument to bond_release that skips some things that don't make sense if all slaves are being released. I'm thinking in particular of this block: 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); } as it's written now, for the release all case, the code may go to the trouble of assigning a new active slave each time one slave is removed (including various log messages, maybe sending IGMPs, etc). If all slaves are being removed, that's pointless. This could be something like: if (release_all) { bond->curr_active_slave = NULL; } else if (oldcurrent == slave) { [ the current block of stuff ] } it's safe here to unconditionally set curr_active_slave to NULL because we hold bond->lock for write. The lock dance stuff for the bond_select_active_slave() call is to satisfy its locking requirements. -J >Signed-off-by: Nikolay Aleksandrov >--- > drivers/net/bonding/bond_main.c | 106 ++-------------------------------------- > 1 file changed, 5 insertions(+), 101 deletions(-) > >diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c >index 94c1534..fcfc880 100644 >--- a/drivers/net/bonding/bond_main.c >+++ b/drivers/net/bonding/bond_main.c >@@ -2140,113 +2140,17 @@ static int bond_release_and_destroy(struct net_device *bond_dev, > /* > * This function releases all slaves. > */ >-static int bond_release_all(struct net_device *bond_dev) >+static void bond_release_all(struct net_device *bond_dev) > { > struct bonding *bond = netdev_priv(bond_dev); >- struct slave *slave; >- struct net_device *slave_dev; >- struct sockaddr addr; >- >- write_lock_bh(&bond->lock); >- >- netif_carrier_off(bond_dev); > > if (bond->slave_cnt == 0) >- goto out; >- >- bond->current_arp_slave = NULL; >- bond->primary_slave = NULL; >- bond_change_active_slave(bond, NULL); >- >- while ((slave = bond->first_slave) != NULL) { >- /* Inform AD package of unbinding of slave >- * before slave is detached from the list. >- */ >- if (bond->params.mode == BOND_MODE_8023AD) >- bond_3ad_unbind_slave(slave); >- >- slave_dev = slave->dev; >- bond_detach_slave(bond, slave); >- >- /* now that the slave is detached, unlock and perform >- * all the undo steps that should not be called from >- * within a lock. >- */ >- write_unlock_bh(&bond->lock); >- >- /* unregister rx_handler early so bond_handle_frame wouldn't >- * be called for this slave anymore. >- */ >- netdev_rx_handler_unregister(slave_dev); >- synchronize_net(); >- >- if (bond_is_lb(bond)) { >- /* must be called only after the slave >- * has been detached from the list >- */ >- bond_alb_deinit_slave(bond, slave); >- } >- >- bond_destroy_slave_symlinks(bond_dev, slave_dev); >- bond_del_vlans_from_slave(bond, slave_dev); >- >- /* If the mode USES_PRIMARY, then we should only remove its >- * promisc and mc settings if it was the curr_active_slave, but that was >- * already taken care of above when we detached the slave >- */ >- if (!USES_PRIMARY(bond->params.mode)) { >- /* unset promiscuity level from slave */ >- if (bond_dev->flags & IFF_PROMISC) >- dev_set_promiscuity(slave_dev, -1); >- >- /* unset allmulti level from slave */ >- if (bond_dev->flags & IFF_ALLMULTI) >- dev_set_allmulti(slave_dev, -1); >- >- /* flush master's mc_list from slave */ >- netif_addr_lock_bh(bond_dev); >- bond_mc_list_flush(bond_dev, slave_dev); >- netif_addr_unlock_bh(bond_dev); >- } >- >- bond_upper_dev_unlink(bond_dev, slave_dev); >- >- slave_disable_netpoll(slave); >- >- /* close slave before restoring its mac address */ >- dev_close(slave_dev); >- >- if (!bond->params.fail_over_mac) { >- /* restore original ("permanent") mac address*/ >- memcpy(addr.sa_data, slave->perm_hwaddr, ETH_ALEN); >- addr.sa_family = slave_dev->type; >- dev_set_mac_address(slave_dev, &addr); >- } >- >- kfree(slave); >- >- /* re-acquire the lock before getting the next slave */ >- write_lock_bh(&bond->lock); >- } >- >- eth_hw_addr_random(bond_dev); >- bond->dev_addr_from_first = true; >- >- if (bond_vlan_used(bond)) { >- pr_warning("%s: Warning: clearing HW address of %s while it still has VLANs.\n", >- bond_dev->name, bond_dev->name); >- pr_warning("%s: When re-adding slaves, make sure the bond's HW address matches its VLANs'.\n", >- bond_dev->name); >- } >- >+ return; >+ while (bond->first_slave != NULL) >+ bond_release(bond_dev, bond->first_slave->dev); > pr_info("%s: released all slaves\n", bond_dev->name); > >-out: >- write_unlock_bh(&bond->lock); >- >- bond_compute_features(bond); >- >- return 0; >+ return; > } > > /* >-- >1.7.11.7 --- -Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com