bug#51425: file-system: validate flags

[Maxim Cournoyer]

Hello Tobias,

Tobias Geerinckx-Rice <me@tobias.gr> writes:

> [FTR, I'm the one who encouraged Jonathan to file a bug.  Mount flags
> seem ideally suited to build-time validation.]
>
> Maxim,
>
> Maxim Cournoyer 写道：
>> each file system may have their own flags
>
> Really?  Huh.  Interesting.  How does that work?  Where would these
> file-system specific flags be #defined?

Or maybe I'm confusing with file system options; I can't find the past
discussion that I had on mind; but options are file driver specific,
while flags are file system independent.  So yes, flags are a good
candidate for validation!

Another thing that is tricky about options is that some of them are only
really understood by the 'mount' command line utility, not the 'mount'
system call such as used in our init RAM disk (both are thrown together
in 'man 8 mount' without an easy way to discern them apart, IIRC).

> Ludo', I'll take a look at ‘sanitize’; thanks!

Neat, thank you Tobias!

Maxim