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. -J --- -Jay Vosburgh, jv@xxxxxxxxxxxxx
