[Devel] [PATCH rh7] ve: Add a ability to show ve.mount_opts

[Kirill Tkhai]

В Вт, 07/07/2015 в 13:51 -0700, Maxim Patlasov пишет:
> Hi Kirill,
> 
> see please inline comment below...
> 
> On 07/06/2015 04:04 AM, Kirill Tkhai wrote:
> > A user may want to see allowed mount options.
> > This patch allows that.
> > 
> > Signed-off-by: Kirill Tkhai <ktkhai at odin.com>
> > ---
> >   kernel/ve/ve.c |   82 
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 82 insertions(+)
> > 
> > diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c
> > index 6496727..4cd1f8b 100644
> > --- a/kernel/ve/ve.c
> > +++ b/kernel/ve/ve.c
> > @@ -929,6 +929,85 @@ static int ve_id_write(struct cgroup *cg, 
> > struct cftype *cft, u64 value)
> >   	return err;
> >   }
> >   
> > +static void *ve_mount_opts_start(struct seq_file *m, loff_t *ppos)
> > +{
> > +	struct ve_struct *ve = m->private;
> > +	struct ve_devmnt *devmnt;
> > +	loff_t pos = *ppos;
> > +
> > +	mutex_lock(&ve->devmnt_mutex);
> > +	list_for_each_entry(devmnt, &ve->devmnt_list, link) {
> > +		if (!pos--)
> > +			return devmnt;
> > +	}
> > +	return NULL;
> > +}
> > +
> > +static void *ve_mount_opts_next(struct seq_file *m, void *v, 
> > loff_t *ppos)
> > +{
> > +	struct ve_struct *ve = m->private;
> > +	struct ve_devmnt *devmnt = v;
> > +
> > +	(*ppos)++;
> > +	if (list_is_last(&devmnt->link, &ve->devmnt_list))
> > +		return NULL;
> > +	return list_entry(devmnt->link.next, struct ve_devmnt, 
> > link);
> > +}
> > +
> > +static void ve_mount_opts_stop(struct seq_file *m, void *v)
> > +{
> > +	struct ve_struct *ve = m->private;
> > +
> > +	mutex_unlock(&ve->devmnt_mutex);
> > +}
> > +
> > +static int ve_mount_opts_show(struct seq_file *m, void *v)
> > +{
> > +	struct ve_devmnt *devmnt = v;
> > +	dev_t dev = devmnt->dev;
> > +
> > +	seq_printf(m, "0 %u:%u;1 %s;2 %s;\n", MAJOR(dev), 
> > MINOR(dev),
> > +					      devmnt
> > ->hidden_options,
> > +					      devmnt
> > ->allowed_options);
> 
> Why do we need to show hidden options to CT' user? He/she doesn't see 
> 
> ".balloon" file, so it doesn't seem consistent to show 
> "balloon_ino=N".

But this way "read" won't show all written using "write". It may
confuse users or vzctl developers.

I think more debug info won't be worse.

Regards,
Kirill