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Re: SoC project suggestion

Alistair Crooks <> writes:

> This project is meant to associate a system and user flag with a file
> in userland, similar to the immutable flags we already have, and, on
> the last unlink of the file, the data blocks would be overwritten. 
> It would be useful to have for shadow password files and dbs (and
> temporary entries), pgp and ssh keys, and other sensitive data that a
> user may have - which is where the user flag comes in.  There are
> various ways of doing this scrubbing, and part of this project is to
> investigate this.

One interesting thing is that this would -- in theory -- allow scrubbing
files on LFS, both on deletion and when blocks are relocated due to
either copy-on-write or the segment cleaner.  Because the cleaner, as I
understand it, already has to walk through the inode to determine if a
block is garbage, it can find out "for free" whether it should overwrite
the block before marking the segment clean.

LFS has bigger problems, of course, and this is likely out of scope for
a SoC project anyway, but it might be worth noting.

(let ((C call-with-current-continuation)) (apply (lambda (x y) (x y)) (map
((lambda (r) ((C C) (lambda (s) (r (lambda l (apply (s s) l))))))  (lambda
(f) (lambda (l) (if (null? l) C (lambda (k) (display (car l)) ((f (cdr l))
(C k)))))))    '((#\J #\d #\D #\v #\s) (#\e #\space #\a #\i #\newline)))))

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