Re: [PATCH] xenconsole: add file lock to xenconsole

[Yufang Zhang <yufang521247@gmail.com>]

On 05/25/2011 01:09 AM, Ian Jackson wrote:
> Yufang Zhang writes ("[Xen-devel] [PATCH] xenconsole: add file lock to xenconsole"):
>> This patch add a file lock to xenconsole for each console id, so
>> that only one console could be attached to a guest at a time.
>> Otherwise, consoles would get stuck and print strange outputs.
> If only we had a better console protocol, it would be possible to
> attach multiple times.  Oh well.  In the meantime your semantic change
> is sensible.
>
> However:
>
>> +static int console_locked(const char *file)
>> +{
>> +        int fd;
>> +
> You need to use the same indent level and coding style as the
> surrounding code.
>
>> +        sprintf(buf, "/tmp/xenconsole-%d-%d", domid, num);
> The lockfile should be in /var/run/xen.  You should use snprintf.
>

Thanks Ian. Version2 patch has been sent, please review.

> What arrangements do you plan to make for cleaning up stale lockfiles
> (which I think will be left behind if the xenconsole client crashes) ?
> Are we just going to rely on them being removed at reboot and apart
> from that let them accumulate a bit ?
>
> Ian.
Considering the lock files are just blank and can be reused, leaving 
them behind is not that bad?

Yufang