On 09/02, Jay Vosburgh wrote: > Stanislav Fomichev <stfomichev@xxxxxxxxx> wrote: > > >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 > > > >? > > I can add these and repost in a day or so. > > >> 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. > > For the sysfs option path, the new setting is validated against > the contents of use_carrier_tbl by __bond_opt_set before the above is > called, so we don't need to check it here. The sysfs parsing accepts > either the number 1 or the text "on", so it's a bit more complicated. Ah, I missed that .values validation part, thanks for the explanation!
