Messages in this thread |  | | Date | Thu, 4 Jul 1996 16:55:20 +0100 | Subject | Re: Drawbacks of implementing undelete entirely in user space | From | Ray Auchterlounie <> |
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In article <Pine.LNX.3.91.960625140632.1810B-100000@gytha.demon.co.uk> Bryn Paul Arnold Jones <bpaj@gytha.demon.co.uk> wrote:
>On Mon, 24 Jun 1996, Ray Auchterlounie wrote: >> Quotas - if deleted files count towards user quota then the facility [...] >Annother per user quota on undelete space would very quickly kill that [...]
I think you would need to extensively modify the existing quota code to do that - I think it only counts per-partition not per-directory. It might be easier just to change the ownership of the deleted files, recording the original owner somewhere else (undelete tools might need to be setuid then).
>> File attributes - at filesystem level we can add file attributes like >> ext2fs "undelete" and "secure delete", undelete can then be specified [...]
>Well unlink doesn't delete, that only happens when the last reference to >the file is lost, so secure deletion will happen anyway, just not >necessarily right now (well that's the case at the moment so ....). The [...]
I think that anyone paranoid enough to be using the secure deletion attribute would check number of links first, and then expect rm to delete/erase the file _now_, not in a years time when the disk gets full, (because the IRS/FBI/Aliens/Wife is on the way with DOS disk and sector editor _now_...).
Actually, having thought about it, there is still a window for someone else to perhaps link to the file, so I think that you would truncate the file first and then remove it to be sure.
Of course, then someone might have provided a helpful undelete which traps truncate and moves the old file...
>Why does he want to lock the filesystem ? Only broken hacks (vfat under [...]
I think he had in mind something like debugfs using /dev/hda1 or whatever - I'm not sure whether this is a good idea on a mounted filesystem (although read-only access would be enough to recover files by copying).
ray
-- Ray Auchterlounie Research Student (still) at: <rda@kythera.demon.co.uk> Signal Processing Group <rda@eng.cam.ac.uk> Cambridge University Engineering Dept. "Don't ask me about my thesis (TM)"
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