On Mon, Aug 11, 2008 at 02:48:49PM +1000, Timothy Shimmin wrote:
> >> + /*
> >> + * Logically we would return an error here to prevent
> >> + * users from believing they might have changed
> >> + * mount options using remount which can't be changed.
> >> + *
> >> + * But unfortunately mount(8) adds all options from
> >> + * mtab and fstab to the mount arguments in some
> >> + * cases so we can't blindly reject options.
> >> + *
> >> + * The workaround for that behaviour will be to
> >> + * check for each specified option whether it actually
> >> + * is a change compared to the status quo and if yes
> >> + * silently ignore it or otherwise reject the remount
> >> + * and tell the user about the reason.
> >> + */
> >> +#if 0
> >> printk(KERN_INFO
> >> "XFS: mount option \"%s\" not supported for remount\n", p);
> >> return -EINVAL;
> >> +#else
> >> + return 0;
> >> +#endif
> I don't follow the 3rd paragraph of the comment above.
> The current workaround looks like to always let the options through
> (ignoring the unallowed changed ones),
> and a better fix would be to compare what the requested opts are with
> the current opts and for the changed one's see if they are allowed
> on remount.
Yes, that's what I wanted to say with the third paragraph :) I'll send
an updated version with a better worded comment once we have concensus
on wether to warn or not.