>Date: Wed, 6 Oct 1999 17:11:41 -0700
>From: Pat Dirks <[EMAIL PROTECTED]>
>>This is very interesting, as a timesaver to the second option
>>(overwriting) you could use the timestamp on the file's permissions
>>to determine if the UID/GIDs are valid (if they are stale old uids,
>>or new uid's after a chown/chgrp)
>That'd be an intriguing optimization. It would require maintaining a
>timestamp for every file and directory on the disk to note the time of
>the last change, though, in addition to the filesystem's timestamp,
>wouldn't it? I suppose you could check that the owner/group IDs are
>corrected if the "last changed date" is ever updated and ignore the
>owner/group IDs if the last changed date is before the filesystem's
>timestamp and thereby incrementally update individual
>filesystems/directories on the filesystem without a lengthy delay at
>"adoption" time.
Please be careful here.
There is absolutely *no* (meta-)information that can be trusted on a
"foreign" medium, unless one can trust each process (computer-originated
or otherwise) that has had the ability to modify anything on the medium.
[Bad analogy follows. Sorry, I can't help myself.] Suppose you give a
kid a sucker. The kid might keep it in his mouth until it's all
consumed, but that's not especially probable. More likely, it's
repeatedly placed in his mouth & taken back out. Often, putting it back
in his mouth is a reasonable thing to do... but it depends on where the
sucker has been in the mean time.
Cheers,
david
--
David Wolfskill [EMAIL PROTECTED] UNIX System Administrator
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