From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpbg154.qq.com (smtpbg154.qq.com [15.184.224.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 09153226D18; Tue, 17 Jun 2025 12:01:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=15.184.224.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750161697; cv=none; b=aRcIDUkq6EdkFpVExdtq2CQbcMsRkbmZ3oRDRj+N049hHncLID7QcHCoeG92Q1wZ6PtGHqoLG7fyDbXkrFNLSbIkcy6b8k757P6649HF4BQgINZHx3DzwYpRDhWR6SDl0PdU4E4QJYLRy5Yzy95YiZGnDR2rbk7EqcaabPl+Ves= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750161697; c=relaxed/simple; bh=HWXAMi5I2vScfvBk2Pv3ly4qguX0MQ9qzW2VP2FkHg0=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=mT4DhAD1JPuS3MNj/klzMgjDRzx7TDcPPhRq80Z5BhuWvqGjcVVlRnBz4IrGAs91cu0N900xjpTd1RlHAXcy91btB8KMeiHKYVMvWTYGxR7hYwh/VzP7682NK3bMH/gxKM3gPoXSSCvUIVEcXy0MSbF4hJj4V427EuSAZlcCVCA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=bamaicloud.com; spf=pass smtp.mailfrom=bamaicloud.com; arc=none smtp.client-ip=15.184.224.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=bamaicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bamaicloud.com X-QQ-mid: esmtpsz16t1750161680t2767c3f3 X-QQ-Originating-IP: i9NYxPWq8xvE6wWdSFTtYXIS8paTuksiL+ssgGya1og= Received: from smtpclient.apple ( [111.202.70.102]) by bizesmtp.qq.com (ESMTP) with id ; Tue, 17 Jun 2025 20:01:17 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 559052300075416651 Content-Type: text/plain; charset=utf-8 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.600.51.1.1\)) Subject: Re: [PATCH net-next] bonding: Remove support for use_carrier = 0 From: Tonghao Zhang In-Reply-To: <1922517.1750109336@famine> Date: Tue, 17 Jun 2025 20:01:07 +0800 Cc: netdev@vger.kernel.org, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Jonathan Corbet , Andrew Lunn , Stanislav Fomichev , Hangbin Liu , linux-doc@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <6CFF2375-252B-4228-A5D2-1144ABB8FDBF@bamaicloud.com> References: <1922517.1750109336@famine> To: Jay Vosburgh X-Mailer: Apple Mail (2.3826.600.51.1.1) X-QQ-SENDSIZE: 520 Feedback-ID: esmtpsz:bamaicloud.com:qybglogicsvrsz:qybglogicsvrsz4a-0 X-QQ-XMAILINFO: N/Ph2bJENH2/SuyMfWOjvyGm+pRl/+Tjyc3mqEho384vGpybt8AvsK6r tRQ/WXy8vCb+DHx/6+tIW/Zyj8u5QbtCqeRQA/egMfUpTC80Tgx0pq2DpeHEfE7Xu0Waeim Wsp8vLZehkPZV0JLkM2YKtls6XLi1OmcVE9A8ye9NUKRYEJ1alDal0w84tUxOo8M4KlM/og 431fftkr6rYIbw6osOHWgCW0OFoEvp1msMn6H7d/tuheAM8lMi+KL+KeFFoam023Zn6g15B iZpHNOoPuJqnMyn2NdGoPr0jm/c8QPZivo2cPLj+lQm9lZYk5asWymLPLQLY3FEpkz3O3fA RF7zFm6Gus/CPs/ecGxOaa9lYbLv19TfbNzqMdeNgsCElkTN6EMCflfLx45F6p0ABYoWZpj ZCXIWS/HKrvnChkoMnl5OGy8g3DAgv1gyMJbdpAkRqbJqfSstk5vvf+ElYyihaXSKEO9GwE BCn3rIFomuLrusRgAnEtoQ25LVzxh144eJKPTZTclGUyJs2XuSJ+bgua7HIDtP4fTXJg4E2 nAbRswDeubgvtOBjkTHalrkvEbC3kGWdHQJzVBEujgzyf5phe7Rie0SDz81xmkJWmPcm76F 6Frxuy7+lhoruCiUzMPn+BhBvJhpDtBJTpsBZ6AJAxwtgzw0WLR+fzF3hJvw9z3pktFnWF/ RDhejWZ4jMZ3xBqw0WTZy+h34n6e9PBmS8FJubqM9eDhMbanGYJl+5HspYa/S591zORIdtF a8JPBCSP8113gibsmqXISxNZMUE7cuRMYvwpxe5DNtAb2PKUxsFNs2ozLNSqdWolr3x7Vw2 yIB4Jn7TCyBG3xEafBS83WTYBHYa61PaHG6eyPWQvoDsw3oDSj0YzHpexL+fikAf+gp0ggD 5o88Z/LNVqGPL6xhSzgTygbHaTZiqOqSkjIFL+l3R2rfXn2tCPs7HCmWwBXhC5Qq7M2Xp5p jC84EFqhYWjWTrlQ5xrYEh90SEn1NqfJ1lJqw8l+bs2sWd3DSjDXXEsnbRh6uix9xsGc= X-QQ-XMRINFO: OD9hHCdaPRBwq3WW+NvGbIU= X-QQ-RECHKSPAM: 0 > 2025=E5=B9=B46=E6=9C=8817=E6=97=A5 05:28=EF=BC=8CJay Vosburgh = =E5=86=99=E9=81=93=EF=BC=9A >=20 > Remove the ability to disable use_carrier in bonding, and remove > all code related to the old link state check that utilizes ethtool or > ioctl to determine the link state of an interface in a bond. >=20 > To avoid acquiring RTNL many times per second, bonding's miimon > link monitor inspects link state under RCU, but not under RTNL. = However, > ethtool implementations in drivers may sleep, and therefore the = ethtool or > ioctl strategy is unsuitable for use with calls into driver ethtool > functions. >=20 > 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. Today, device drivers = are > expected to support netif_carrier_*, and the use_carrier backwards > compatibility logic is no longer necessary. >=20 > Bonding now always behaves as if use_carrier=3D1, which relies on > netif_carrier_ok() to determine the link state of interfaces. This = has > been the default setting for use_carrier since its introduction. For > backwards compatibility, the option itself remains, but may only be = set to > 1, and queries will always return 1. >=20 > Reported-by: syzbot+b8c48ea38ca27d150063@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=3Db8c48ea38ca27d150063 > Link: = https://lore.kernel.org/lkml/000000000000eb54bf061cfd666a@google.com/ > Link: = https://lore.kernel.org/netdev/20240718122017.d2e33aaac43a.I10ab9c9ded9716= 3aef4e4de10985cd8f7de60d28@changeid/ > Link: http://lore.kernel.org/netdev/aEt6LvBMwUMxmUyx@mini-arch > Signed-off-by: Jay Vosburgh >=20 > --- > Documentation/networking/bonding.rst | 79 +++---------------- > drivers/net/bonding/bond_main.c | 113 ++------------------------- > drivers/net/bonding/bond_netlink.c | 11 +-- > drivers/net/bonding/bond_options.c | 7 +- > drivers/net/bonding/bond_sysfs.c | 6 +- > include/net/bonding.h | 1 - > 6 files changed, 25 insertions(+), 192 deletions(-) >=20 > diff --git a/Documentation/networking/bonding.rst = b/Documentation/networking/bonding.rst > index a4c1291d2561..4ee20f6ab733 100644 > --- a/Documentation/networking/bonding.rst > +++ b/Documentation/networking/bonding.rst > @@ -576,10 +576,8 @@ 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. >=20 > min_links >=20 > @@ -889,25 +887,14 @@ updelay >=20 > use_carrier >=20 > - 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. >=20 > xmit_hash_policy >=20 > @@ -2029,22 +2016,8 @@ 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. >=20 > -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). >=20 > 8. Potential Sources of Trouble > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D > @@ -2128,34 +2101,6 @@ 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. >=20 > -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=3D0 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=3D0 method of querying the registers directly works). If > -use_carrier=3D0 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 > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >=20 > diff --git a/drivers/net/bonding/bond_main.c = b/drivers/net/bonding/bond_main.c > index c4d53e8e7c15..3534561fd932 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, "Obsolete, has no effect"); > module_param(mode, charp, 0); > MODULE_PARM_DESC(mode, "Mode of operation; 0 for balance-rr, " > "1 for active-backup, 2 for balance-xor, " > @@ -828,77 +827,6 @@ const char *bond_slave_link_status(s8 link) > } > } >=20 > -/* if 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 =3D 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 =3D 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 =3D if_mii(&ifr); > - > - if (dev_eth_ioctl(slave_dev, &ifr, SIOCGMIIPHY) =3D=3D 0) { > - mii->reg_num =3D MII_BMSR; > - if (dev_eth_ioctl(slave_dev, &ifr, SIOCGMIIREG) =3D=3D 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 = ------------------------------*/ >=20 > /* Push the promiscuity flag down to appropriate slaves */ > @@ -1949,7 +1877,6 @@ int bond_enslave(struct net_device *bond_dev, = struct net_device *slave_dev, > const struct net_device_ops *slave_ops =3D slave_dev->netdev_ops; > struct slave *new_slave =3D NULL, *prev_slave; > struct sockaddr_storage ss; > - int link_reporting; > int res =3D 0, i; >=20 > if (slave_dev->flags & IFF_MASTER && > @@ -1959,12 +1886,6 @@ int bond_enslave(struct net_device *bond_dev, = struct net_device *slave_dev, > return -EPERM; > } >=20 > - if (!bond->params.use_carrier && > - slave_dev->ethtool_ops->get_link =3D=3D NULL && > - slave_ops->ndo_eth_ioctl =3D=3D 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, > @@ -2178,29 +2099,10 @@ int bond_enslave(struct net_device *bond_dev, = struct net_device *slave_dev, >=20 > new_slave->last_tx =3D new_slave->last_rx; >=20 > - if (bond->params.miimon && !bond->params.use_carrier) { > - link_reporting =3D bond_check_dev_link(bond, slave_dev, 1); > - > - if ((link_reporting =3D=3D -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 =3D=3D -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 =3D BOND_LINK_NOCHANGE; > if (bond->params.miimon) { > - if (bond_check_dev_link(bond, slave_dev, 0) =3D=3D BMSR_LSTATUS) { > + if (netif_carrier_ok(slave_dev)) { > if (bond->params.updelay) { > bond_set_slave_link_state(new_slave, > BOND_LINK_BACK, > @@ -2742,7 +2644,7 @@ static int bond_miimon_inspect(struct bonding = *bond) > bond_for_each_slave_rcu(bond, slave, iter) { > bond_propose_link_state(slave, BOND_LINK_NOCHANGE); >=20 > - link_state =3D bond_check_dev_link(bond, slave->dev, 0); > + link_state =3D netif_carrier_ok(slave->dev); >=20 > switch (slave->link) { > case BOND_LINK_UP: > @@ -6189,10 +6091,10 @@ static int __init bond_check_params(struct = bond_params *params) > downdelay =3D 0; > } >=20 > - if ((use_carrier !=3D 0) && (use_carrier !=3D 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 =3D 1; > + if (use_carrier !=3D 1) { > + pr_err("Error: invalid use_carrier parameter (%d)\n", > + use_carrier); > + return -EINVAL; > } >=20 > if (num_peer_notif < 0 || num_peer_notif > 255) { > @@ -6439,7 +6341,6 @@ static int __init bond_check_params(struct = bond_params *params) > params->updelay =3D updelay; > params->downdelay =3D downdelay; > params->peer_notif_delay =3D 0; > - params->use_carrier =3D use_carrier; > params->lacp_active =3D 1; > params->lacp_fast =3D lacp_fast; > params->primary[0] =3D 0; > diff --git a/drivers/net/bonding/bond_netlink.c = b/drivers/net/bonding/bond_netlink.c > index ac5e402c34bc..98f9bef61474 100644 > --- a/drivers/net/bonding/bond_netlink.c > +++ b/drivers/net/bonding/bond_netlink.c > @@ -258,13 +258,8 @@ static int bond_changelink(struct net_device = *bond_dev, struct nlattr *tb[], > return err; > } > if (data[IFLA_BOND_USE_CARRIER]) { > - int use_carrier =3D nla_get_u8(data[IFLA_BOND_USE_CARRIER]); > - > - bond_opt_initval(&newval, use_carrier); > - err =3D __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]) !=3D 1) > + return -EINVAL; > } > if (data[IFLA_BOND_ARP_INTERVAL]) { > int arp_interval =3D nla_get_u32(data[IFLA_BOND_ARP_INTERVAL]); > @@ -676,7 +671,7 @@ static int bond_fill_info(struct sk_buff *skb, > bond->params.peer_notif_delay * bond->params.miimon)) > goto nla_put_failure; >=20 > - 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; >=20 > 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 91893c29b899..98dbee2b6aba 100644 > --- a/drivers/net/bonding/bond_options.c > +++ b/drivers/net/bonding/bond_options.c > @@ -185,7 +185,6 @@ static const struct bond_opt_value = bond_primary_reselect_tbl[] =3D { > }; >=20 > static const struct bond_opt_value bond_use_carrier_tbl[] =3D { > - { "off", 0, 0}, > { "on", 1, BOND_VALFLAG_DEFAULT}, > { NULL, -1, 0} > }; Your other patch deletes these lines. > @@ -411,7 +410,7 @@ static const struct bond_option = bond_opts[BOND_OPT_LAST] =3D { > [BOND_OPT_USE_CARRIER] =3D { > .id =3D BOND_OPT_USE_CARRIER, > .name =3D "use_carrier", > - .desc =3D "Use netif_carrier_ok (vs MII ioctls) in miimon", > + .desc =3D "Obsolete, has no effect=E2=80=9D, Add more information? "Obsolete, option has no effect, netif_carrier_ok = used as default" >=20 > .values =3D bond_use_carrier_tbl, > .set =3D bond_option_use_carrier_set > }, > @@ -1068,10 +1067,6 @@ 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 =3D newval->value; > - > return 0; > } >=20 > diff --git a/drivers/net/bonding/bond_sysfs.c = b/drivers/net/bonding/bond_sysfs.c > index 1e13bb170515..9a75ad3181ab 100644 > --- a/drivers/net/bonding/bond_sysfs.c > +++ b/drivers/net/bonding/bond_sysfs.c > @@ -467,14 +467,12 @@ static ssize_t = bonding_show_primary_reselect(struct device *d, > static DEVICE_ATTR(primary_reselect, 0644, > bonding_show_primary_reselect, bonding_sysfs_store_option); >=20 > -/* Show the use_carrier flag. */ > +/* use_carrier is obsolete, but print value for compatibility */ > static ssize_t bonding_show_carrier(struct device *d, > struct device_attribute *attr, > char *buf) > { > - struct bonding *bond =3D to_bond(d); > - > - return sysfs_emit(buf, "%d\n", bond->params.use_carrier); > + return sysfs_emit(buf, "1\n"); > } > static DEVICE_ATTR(use_carrier, 0644, > bonding_show_carrier, bonding_sysfs_store_option); > diff --git a/include/net/bonding.h b/include/net/bonding.h > index 95f67b308c19..6fdf4d1e5256 100644 > --- a/include/net/bonding.h > +++ b/include/net/bonding.h > @@ -124,7 +124,6 @@ struct bond_params { > int arp_interval; > int arp_validate; > int arp_all_targets; > - int use_carrier; > int fail_over_mac; > int updelay; > int downdelay; > --=20 > 2.25.1 >=20 >=20 >=20