Reply: [net] bonding: use return instead of goto
> On Fri, Feb 05, 2016 at 09:42:24AM +0800, 张胜举 wrote: > > > On Wed, Feb 03, 2016 at 06:15:22AM +, Zhang Shengju wrote: > > > > Replace 'goto' with 'return' to remove unnecessary check at label: > > > > err_undo_flags. > > > > > > I think you're going to have to explain how you came to the > > > conclusion that the check isn't necessary. > ... > > The reason is that 'err_undo_flags' do two things for the first slave > > device: > > 1. revert bond mac address if it is set by the slave device. > > 2. revert bond device type if it's not ARPHRD_ETHER. > > > > I think it's not necessary for the three places, they changed neither > > bond mac address nor type. > > it's straightforward to return directly. > > I see what you're saying, and that does look to be true if you're only adding > a > singular first device right now. But looking at the enslave and release > paths, I > don't see anything preventing concurrent slave adds and removes, which > could mean there are situations where those checks really are necessary. I > don't actually know. > > -- > Jarod Wilson > ja...@redhat.com All of three places don't change any attributes of bond device, just for sanity check before enslaving. If it's necessary for these three places to goto 'err_undo_flags', it will mean that all sanity checks before these three places need to do so, which is not right clearly. Even there is concurrent situation which make the check necessary, which I haven't figure out yet, it's not right place to do this. Thanks, Shengju
Re: Reply: [net] bonding: use return instead of goto
On Fri, Feb 05, 2016 at 09:42:24AM +0800, 张胜举 wrote: > > On Wed, Feb 03, 2016 at 06:15:22AM +, Zhang Shengju wrote: > > > Replace 'goto' with 'return' to remove unnecessary check at label: > > > err_undo_flags. > > > > I think you're going to have to explain how you came to the conclusion > > that the check isn't necessary. ... > The reason is that 'err_undo_flags' do two things for the first slave > device: > 1. revert bond mac address if it is set by the slave device. > 2. revert bond device type if it's not ARPHRD_ETHER. > > I think it's not necessary for the three places, they changed neither bond > mac address nor type. > it's straightforward to return directly. I see what you're saying, and that does look to be true if you're only adding a singular first device right now. But looking at the enslave and release paths, I don't see anything preventing concurrent slave adds and removes, which could mean there are situations where those checks really are necessary. I don't actually know. -- Jarod Wilson ja...@redhat.com
Reply: [net] bonding: use return instead of goto
> On Wed, Feb 03, 2016 at 06:15:22AM +, Zhang Shengju wrote: > > Replace 'goto' with 'return' to remove unnecessary check at label: > > err_undo_flags. > > I think you're going to have to explain how you came to the conclusion that > the check isn't necessary. > > -- > Jarod Wilson > ja...@redhat.com Hi Jarod, The reason is that 'err_undo_flags' do two things for the first slave device: 1. revert bond mac address if it is set by the slave device. 2. revert bond device type if it's not ARPHRD_ETHER. I think it's not necessary for the three places, they changed neither bond mac address nor type. it's straightforward to return directly. Thanks, Shengju
Re: [net] bonding: use return instead of goto
On Wed, Feb 03, 2016 at 06:15:22AM +, Zhang Shengju wrote: > Replace 'goto' with 'return' to remove unnecessary check at label: > err_undo_flags. I think you're going to have to explain how you came to the conclusion that the check isn't necessary. -- Jarod Wilson ja...@redhat.com
[net] bonding: use return instead of goto
Replace 'goto' with 'return' to remove unnecessary check at label: err_undo_flags. Signed-off-by: Zhang Shengju --- drivers/net/bonding/bond_main.c | 9 +++-- 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index bcc7b19..abe014f 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1379,8 +1379,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev) if (slave_dev->flags & IFF_UP) { netdev_err(bond_dev, "%s is up - this may be due to an out of date ifenslave\n", slave_dev->name); - res = -EPERM; - goto err_undo_flags; + return -EPERM; } /* set bonding device ether type by slave - bonding netdevices are @@ -1400,8 +1399,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev) res = notifier_to_errno(res); if (res) { netdev_err(bond_dev, "refused to change device type\n"); - res = -EBUSY; - goto err_undo_flags; + return -EBUSY; } /* Flush unicast and multicast addresses */ @@ -1421,8 +1419,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev) } else if (bond_dev->type != slave_dev->type) { netdev_err(bond_dev, "%s ether type (%d) is different from other slaves (%d), can not enslave it\n", slave_dev->name, slave_dev->type, bond_dev->type); - res = -EINVAL; - goto err_undo_flags; + return -EINVAL; } if (slave_ops->ndo_set_mac_address == NULL) { -- 1.8.3.1