Re: [PATCH] vfs: Don't reject unknown parameters

[Al Viro]

On Fri, Dec 13, 2019 at 10:15:03AM +0100, Miklos Szeredi wrote:

> Just need a flag in fc indicating if this option comes from the old interface:
> 
>          if (strcmp(param->key, "source") == 0)
>                  return -ENOPARAM;
>          /* Just log an error for backwards compatibility */
>          errorf(fc, "%s: Unknown parameter '%s'", fc->fs_type->name,
> param->key);
>          return fc->legacy ? 0 : -ENOPARAM;

	What the hell for?  Just have a separate ->parse_param() instance
for "promiscuous fs, will accept bullshit options" and have such filesystems
use it explicitly.  With default being not that, but rejecting unknowns.