The following call chain indicates that bond_do_ioctl() is protected under rtnl_lock. If we use __dev_get_by_name() instead of dev_get_by_name() to find interface handler in it, this would help us avoid to change reference counter of interface once.
dev_ioctl() rtnl_lock() dev_ifsioc() bond_do_ioctl() rtnl_unlock() Additionally we also change the coding style in bond_do_ioctl(), letting it more readable for us. Cc: Jay Vosburgh <fu...@us.ibm.com> Cc: Veaceslav Falico <vfal...@redhat.com> Signed-off-by: Ying Xue <ying....@windriver.com> --- drivers/net/bonding/bond_main.c | 49 ++++++++++++++++++--------------------- 1 file changed, 23 insertions(+), 26 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index e06c445..a69afbf 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3213,37 +3213,34 @@ static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) return -EPERM; - slave_dev = dev_get_by_name(net, ifr->ifr_slave); + slave_dev = __dev_get_by_name(net, ifr->ifr_slave); pr_debug("slave_dev=%p:\n", slave_dev); if (!slave_dev) - res = -ENODEV; - else { - pr_debug("slave_dev->name=%s:\n", slave_dev->name); - switch (cmd) { - case BOND_ENSLAVE_OLD: - case SIOCBONDENSLAVE: - res = bond_enslave(bond_dev, slave_dev); - break; - case BOND_RELEASE_OLD: - case SIOCBONDRELEASE: - res = bond_release(bond_dev, slave_dev); - break; - case BOND_SETHWADDR_OLD: - case SIOCBONDSETHWADDR: - bond_set_dev_addr(bond_dev, slave_dev); - res = 0; - break; - case BOND_CHANGE_ACTIVE_OLD: - case SIOCBONDCHANGEACTIVE: - res = bond_option_active_slave_set(bond, slave_dev); - break; - default: - res = -EOPNOTSUPP; - } + return -ENODEV; - dev_put(slave_dev); + pr_debug("slave_dev->name=%s:\n", slave_dev->name); + switch (cmd) { + case BOND_ENSLAVE_OLD: + case SIOCBONDENSLAVE: + res = bond_enslave(bond_dev, slave_dev); + break; + case BOND_RELEASE_OLD: + case SIOCBONDRELEASE: + res = bond_release(bond_dev, slave_dev); + break; + case BOND_SETHWADDR_OLD: + case SIOCBONDSETHWADDR: + bond_set_dev_addr(bond_dev, slave_dev); + res = 0; + break; + case BOND_CHANGE_ACTIVE_OLD: + case SIOCBONDCHANGEACTIVE: + res = bond_option_active_slave_set(bond, slave_dev); + break; + default: + res = -EOPNOTSUPP; } return res; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/