On 08/29, Jay Vosburgh wrote: > Remove the implementation of use_carrier, the link monitoring > method that utilizes ethtool or ioctl to determine the link state of an > interface in a bond. Bonding will always behaves as if use_carrier=1, > which relies on netif_carrier_ok() to determine the link state of > interfaces. > > To avoid acquiring RTNL many times per second, bonding inspects > link state under RCU, but not under RTNL. However, ethtool > implementations in drivers may sleep, and therefore this strategy is > unsuitable for use with calls into driver ethtool functions. > > The use_carrier option was introduced in 2003, to provide > backwards compatibility for network device drivers that did not support > the then-new netif_carrier_ok/on/off system. Device drivers are now > expected to support netif_carrier_*, and the use_carrier backwards > compatibility logic is no longer necessary. > > The option itself remains, but when queried always returns 1, > and may only be set to 1. > > Link: https://lore.kernel.org/lkml/000000000000eb54bf061cfd666a@xxxxxxxxxx/ > Link: https://lore.kernel.org/netdev/20240718122017.d2e33aaac43a.I10ab9c9ded97163aef4e4de10985cd8f7de60d28@changeid/ > Signed-off-by: Jay Vosburgh <jv@xxxxxxxxxxxxx> > > --- > > Note: Deliberately omitting a Fixes tag to avoid removing functionality > in older kernels that may be in use. What about syzbot metadata? Reported-by: syzbot+b8c48ea38ca27d150063@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=b8c48ea38ca27d150063 ? > Documentation/networking/bonding.rst | 79 +++---------------- > drivers/net/bonding/bond_main.c | 113 ++------------------------- > drivers/net/bonding/bond_netlink.c | 14 ++-- > drivers/net/bonding/bond_options.c | 7 +- > drivers/net/bonding/bond_sysfs.c | 6 +- > include/net/bonding.h | 1 - > 6 files changed, 28 insertions(+), 192 deletions(-) > > diff --git a/Documentation/networking/bonding.rst b/Documentation/networking/bonding.rst > index f8f5766703d4..a2b42ae719d2 100644 > --- a/Documentation/networking/bonding.rst > +++ b/Documentation/networking/bonding.rst > @@ -582,10 +582,8 @@ miimon > This determines how often the link state of each slave is > inspected for link failures. A value of zero disables MII > link monitoring. A value of 100 is a good starting point. > - The use_carrier option, below, affects how the link state is > - determined. See the High Availability section for additional > - information. The default value is 100 if arp_interval is not > - set. > + > + The default value is 100 if arp_interval is not set. > > min_links > > @@ -896,25 +894,14 @@ updelay > > use_carrier > > - Specifies whether or not miimon should use MII or ETHTOOL > - ioctls vs. netif_carrier_ok() to determine the link > - status. The MII or ETHTOOL ioctls are less efficient and > - utilize a deprecated calling sequence within the kernel. The > - netif_carrier_ok() relies on the device driver to maintain its > - state with netif_carrier_on/off; at this writing, most, but > - not all, device drivers support this facility. > - > - If bonding insists that the link is up when it should not be, > - it may be that your network device driver does not support > - netif_carrier_on/off. The default state for netif_carrier is > - "carrier on," so if a driver does not support netif_carrier, > - it will appear as if the link is always up. In this case, > - setting use_carrier to 0 will cause bonding to revert to the > - MII / ETHTOOL ioctl method to determine the link state. > - > - A value of 1 enables the use of netif_carrier_ok(), a value of > - 0 will use the deprecated MII / ETHTOOL ioctls. The default > - value is 1. > + Obsolete option that previously selected between MII / > + ETHTOOL ioctls and netif_carrier_ok() to determine link > + state. > + > + All link state checks are now done with netif_carrier_ok(). > + > + For backwards compatibility, this option's value may be inspected > + or set. The only valid setting is 1. > > xmit_hash_policy > > @@ -2036,22 +2023,8 @@ depending upon the device driver to maintain its carrier state, by > querying the device's MII registers, or by making an ethtool query to > the device. > > -If the use_carrier module parameter is 1 (the default value), > -then the MII monitor will rely on the driver for carrier state > -information (via the netif_carrier subsystem). As explained in the > -use_carrier parameter information, above, if the MII monitor fails to > -detect carrier loss on the device (e.g., when the cable is physically > -disconnected), it may be that the driver does not support > -netif_carrier. > - > -If use_carrier is 0, then the MII monitor will first query the > -device's (via ioctl) MII registers and check the link state. If that > -request fails (not just that it returns carrier down), then the MII > -monitor will make an ethtool ETHTOOL_GLINK request to attempt to obtain > -the same information. If both methods fail (i.e., the driver either > -does not support or had some error in processing both the MII register > -and ethtool requests), then the MII monitor will assume the link is > -up. > +The MII monitor relies on the driver for carrier state information (via > +the netif_carrier subsystem). > > 8. Potential Sources of Trouble > =============================== > @@ -2135,34 +2108,6 @@ This will load tg3 and e1000 modules before loading the bonding one. > Full documentation on this can be found in the modprobe.d and modprobe > manual pages. > > -8.3. Painfully Slow Or No Failed Link Detection By Miimon > ---------------------------------------------------------- > - > -By default, bonding enables the use_carrier option, which > -instructs bonding to trust the driver to maintain carrier state. > - > -As discussed in the options section, above, some drivers do > -not support the netif_carrier_on/_off link state tracking system. > -With use_carrier enabled, bonding will always see these links as up, > -regardless of their actual state. > - > -Additionally, other drivers do support netif_carrier, but do > -not maintain it in real time, e.g., only polling the link state at > -some fixed interval. In this case, miimon will detect failures, but > -only after some long period of time has expired. If it appears that > -miimon is very slow in detecting link failures, try specifying > -use_carrier=0 to see if that improves the failure detection time. If > -it does, then it may be that the driver checks the carrier state at a > -fixed interval, but does not cache the MII register values (so the > -use_carrier=0 method of querying the registers directly works). If > -use_carrier=0 does not improve the failover, then the driver may cache > -the registers, or the problem may be elsewhere. > - > -Also, remember that miimon only checks for the device's > -carrier state. It has no way to determine the state of devices on or > -beyond other ports of a switch, or if a switch is refusing to pass > -traffic while still maintaining carrier on. > - > 9. SNMP agents > =============== > > diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c > index 257333c88710..f25c2d2c9181 100644 > --- a/drivers/net/bonding/bond_main.c > +++ b/drivers/net/bonding/bond_main.c > @@ -142,8 +142,7 @@ module_param(downdelay, int, 0); > MODULE_PARM_DESC(downdelay, "Delay before considering link down, " > "in milliseconds"); > module_param(use_carrier, int, 0); > -MODULE_PARM_DESC(use_carrier, "Use netif_carrier_ok (vs MII ioctls) in miimon; " > - "0 for off, 1 for on (default)"); > +MODULE_PARM_DESC(use_carrier, "option obsolete, use_carrier cannot be disabled"); > module_param(mode, charp, 0); > MODULE_PARM_DESC(mode, "Mode of operation; 0 for balance-rr, " > "1 for active-backup, 2 for balance-xor, " > @@ -830,77 +829,6 @@ const char *bond_slave_link_status(s8 link) > } > } > > -/* if <dev> supports MII link status reporting, check its link status. > - * > - * We either do MII/ETHTOOL ioctls, or check netif_carrier_ok(), > - * depending upon the setting of the use_carrier parameter. > - * > - * Return either BMSR_LSTATUS, meaning that the link is up (or we > - * can't tell and just pretend it is), or 0, meaning that the link is > - * down. > - * > - * If reporting is non-zero, instead of faking link up, return -1 if > - * both ETHTOOL and MII ioctls fail (meaning the device does not > - * support them). If use_carrier is set, return whatever it says. > - * It'd be nice if there was a good way to tell if a driver supports > - * netif_carrier, but there really isn't. > - */ > -static int bond_check_dev_link(struct bonding *bond, > - struct net_device *slave_dev, int reporting) > -{ > - const struct net_device_ops *slave_ops = slave_dev->netdev_ops; > - struct mii_ioctl_data *mii; > - struct ifreq ifr; > - int ret; > - > - if (!reporting && !netif_running(slave_dev)) > - return 0; > - > - if (bond->params.use_carrier) > - return netif_carrier_ok(slave_dev) ? BMSR_LSTATUS : 0; > - > - /* Try to get link status using Ethtool first. */ > - if (slave_dev->ethtool_ops->get_link) { > - netdev_lock_ops(slave_dev); > - ret = slave_dev->ethtool_ops->get_link(slave_dev); > - netdev_unlock_ops(slave_dev); > - > - return ret ? BMSR_LSTATUS : 0; > - } > - > - /* Ethtool can't be used, fallback to MII ioctls. */ > - if (slave_ops->ndo_eth_ioctl) { > - /* TODO: set pointer to correct ioctl on a per team member > - * bases to make this more efficient. that is, once > - * we determine the correct ioctl, we will always > - * call it and not the others for that team > - * member. > - */ > - > - /* We cannot assume that SIOCGMIIPHY will also read a > - * register; not all network drivers (e.g., e100) > - * support that. > - */ > - > - /* Yes, the mii is overlaid on the ifreq.ifr_ifru */ > - strscpy_pad(ifr.ifr_name, slave_dev->name, IFNAMSIZ); > - mii = if_mii(&ifr); > - > - if (dev_eth_ioctl(slave_dev, &ifr, SIOCGMIIPHY) == 0) { > - mii->reg_num = MII_BMSR; > - if (dev_eth_ioctl(slave_dev, &ifr, SIOCGMIIREG) == 0) > - return mii->val_out & BMSR_LSTATUS; > - } > - } > - > - /* If reporting, report that either there's no ndo_eth_ioctl, > - * or both SIOCGMIIREG and get_link failed (meaning that we > - * cannot report link status). If not reporting, pretend > - * we're ok. > - */ > - return reporting ? -1 : BMSR_LSTATUS; > -} > - > /*----------------------------- Multicast list ------------------------------*/ > > /* Push the promiscuity flag down to appropriate slaves */ > @@ -1966,7 +1894,6 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev, > const struct net_device_ops *slave_ops = slave_dev->netdev_ops; > struct slave *new_slave = NULL, *prev_slave; > struct sockaddr_storage ss; > - int link_reporting; > int res = 0, i; > > if (slave_dev->flags & IFF_MASTER && > @@ -1976,12 +1903,6 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev, > return -EPERM; > } > > - if (!bond->params.use_carrier && > - slave_dev->ethtool_ops->get_link == NULL && > - slave_ops->ndo_eth_ioctl == NULL) { > - slave_warn(bond_dev, slave_dev, "no link monitoring support\n"); > - } > - > /* already in-use? */ > if (netdev_is_rx_handler_busy(slave_dev)) { > SLAVE_NL_ERR(bond_dev, slave_dev, extack, > @@ -2195,29 +2116,10 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev, > > new_slave->last_tx = new_slave->last_rx; > > - if (bond->params.miimon && !bond->params.use_carrier) { > - link_reporting = bond_check_dev_link(bond, slave_dev, 1); > - > - if ((link_reporting == -1) && !bond->params.arp_interval) { > - /* miimon is set but a bonded network driver > - * does not support ETHTOOL/MII and > - * arp_interval is not set. Note: if > - * use_carrier is enabled, we will never go > - * here (because netif_carrier is always > - * supported); thus, we don't need to change > - * the messages for netif_carrier. > - */ > - slave_warn(bond_dev, slave_dev, "MII and ETHTOOL support not available for slave, and arp_interval/arp_ip_target module parameters not specified, thus bonding will not detect link failures! see bonding.txt for details\n"); > - } else if (link_reporting == -1) { > - /* unable get link status using mii/ethtool */ > - slave_warn(bond_dev, slave_dev, "can't get link status from slave; the network driver associated with this interface does not support MII or ETHTOOL link status reporting, thus miimon has no effect on this interface\n"); > - } > - } > - > /* check for initial state */ > new_slave->link = BOND_LINK_NOCHANGE; > if (bond->params.miimon) { > - if (bond_check_dev_link(bond, slave_dev, 0) == BMSR_LSTATUS) { > + if (netif_carrier_ok(slave_dev)) { > if (bond->params.updelay) { > bond_set_slave_link_state(new_slave, > BOND_LINK_BACK, > @@ -2759,7 +2661,7 @@ static int bond_miimon_inspect(struct bonding *bond) > bond_for_each_slave_rcu(bond, slave, iter) { > bond_propose_link_state(slave, BOND_LINK_NOCHANGE); > > - link_state = bond_check_dev_link(bond, slave->dev, 0); > + link_state = netif_carrier_ok(slave->dev); > > switch (slave->link) { > case BOND_LINK_UP: > @@ -6257,10 +6159,10 @@ static int __init bond_check_params(struct bond_params *params) > downdelay = 0; > } > > - if ((use_carrier != 0) && (use_carrier != 1)) { > - pr_warn("Warning: use_carrier module parameter (%d), not of valid value (0/1), so it was set to 1\n", > - use_carrier); > - use_carrier = 1; > + if (use_carrier != 1) { > + pr_err("Error: invalid use_carrier parameter (%d)\n", > + use_carrier); > + return -EINVAL; > } > > if (num_peer_notif < 0 || num_peer_notif > 255) { > @@ -6507,7 +6409,6 @@ static int __init bond_check_params(struct bond_params *params) > params->updelay = updelay; > params->downdelay = downdelay; > params->peer_notif_delay = 0; > - params->use_carrier = use_carrier; > params->lacp_active = 1; > params->lacp_fast = lacp_fast; > params->primary[0] = 0; > diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c > index 57fff2421f1b..e573b34a1bbc 100644 > --- a/drivers/net/bonding/bond_netlink.c > +++ b/drivers/net/bonding/bond_netlink.c > @@ -259,13 +259,11 @@ static int bond_changelink(struct net_device *bond_dev, struct nlattr *tb[], > return err; > } > if (data[IFLA_BOND_USE_CARRIER]) { > - int use_carrier = nla_get_u8(data[IFLA_BOND_USE_CARRIER]); > - > - bond_opt_initval(&newval, use_carrier); > - err = __bond_opt_set(bond, BOND_OPT_USE_CARRIER, &newval, > - data[IFLA_BOND_USE_CARRIER], extack); > - if (err) > - return err; > + if (nla_get_u8(data[IFLA_BOND_USE_CARRIER]) != 1) { > + NL_SET_ERR_MSG_ATTR(extack, data[IFLA_BOND_USE_CARRIER], > + "option obsolete, use_carrier cannot be disabled"); > + return -EINVAL; > + } > } > if (data[IFLA_BOND_ARP_INTERVAL]) { > int arp_interval = nla_get_u32(data[IFLA_BOND_ARP_INTERVAL]); > @@ -688,7 +686,7 @@ static int bond_fill_info(struct sk_buff *skb, > bond->params.peer_notif_delay * bond->params.miimon)) > goto nla_put_failure; > > - if (nla_put_u8(skb, IFLA_BOND_USE_CARRIER, bond->params.use_carrier)) > + if (nla_put_u8(skb, IFLA_BOND_USE_CARRIER, 1)) > goto nla_put_failure; > > if (nla_put_u32(skb, IFLA_BOND_ARP_INTERVAL, bond->params.arp_interval)) > diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c > index 3b6f815c55ff..c0a5eb8766b5 100644 > --- a/drivers/net/bonding/bond_options.c > +++ b/drivers/net/bonding/bond_options.c > @@ -187,7 +187,6 @@ static const struct bond_opt_value bond_primary_reselect_tbl[] = { > }; > > static const struct bond_opt_value bond_use_carrier_tbl[] = { > - { "off", 0, 0}, > { "on", 1, BOND_VALFLAG_DEFAULT}, > { NULL, -1, 0} > }; > @@ -419,7 +418,7 @@ static const struct bond_option bond_opts[BOND_OPT_LAST] = { > [BOND_OPT_USE_CARRIER] = { > .id = BOND_OPT_USE_CARRIER, > .name = "use_carrier", > - .desc = "Use netif_carrier_ok (vs MII ioctls) in miimon", > + .desc = "option obsolete, use_carrier cannot be disabled", > .values = bond_use_carrier_tbl, > .set = bond_option_use_carrier_set > }, > @@ -1091,10 +1090,6 @@ static int bond_option_peer_notif_delay_set(struct bonding *bond, > static int bond_option_use_carrier_set(struct bonding *bond, > const struct bond_opt_value *newval) > { > - netdev_dbg(bond->dev, "Setting use_carrier to %llu\n", > - newval->value); > - bond->params.use_carrier = newval->value; > - > return 0; Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxxx> nit: any reason not to return -EINVAL here when the new value is not "1"? You do it for the module param, but not for the sysfs file here.
