Re: [PATCH 7/8] net: Allow setting the network namespace by fd

From: Eric W. Biederman
Date: Thu Sep 23 2010 - 12:16:20 EST


Brian Haley <brian.haley@xxxxxx> writes:

> On 09/23/2010 04:51 AM, Eric W. Biederman wrote:
>>
>> Take advantage of the new abstraction and allow network devices
>> to be placed in any network namespace that we have a fd to talk
>> about.
>>
> ...
>> +struct net *get_net_ns_by_fd(int fd)
>> +{
>> + struct proc_inode *ei;
>> + struct file *file;
>> + struct net *net;
>> +
>> + file = NULL;
>
> No need to initialize this.
>
>> + net = ERR_PTR(-EINVAL);
>
> or this?
>
>> + file = proc_ns_fget(fd);
>> + if (!fd)
>> + goto out;
>> + return ERR_PTR(-EINVAL);
>
> Shouldn't this be:
>
> if (!file)
>
> And the "goto" seems wrong, especially without a {} here. Unless you
> meant to keep the "goto" and branch below?

I think I changed my mind half way through writing the code and never
did anything about it. Oops.

Thanks fixed. It is now:

struct net *get_net_ns_by_fd(int fd)
{
struct proc_inode *ei;
struct file *file;
struct net *net;

net = ERR_PTR(-EINVAL);
file = proc_ns_fget(fd);
if (!file)
goto out;

ei = PROC_I(file->f_dentry->d_inode);
if (ei->ns_ops != &netns_operations)
goto out;

net = get_net(ei->ns);
out:
if (file)
fput(file);
return net;
}

Which at least makes sense. Now to test it to double check it does what
it should do.

Eric
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