🚀 go-pugleaf

markm@bcaricb3.bnr.ca (Mark Mielke) writes:

>I think what people want is something like MS-DOS's undelete functionality,
>and this _does_ pretty much have to be built into the kernel.

I think different people want different things.

Some people only want to deal with users who mess up with the 'rm'
command.  This is easily dealt with through aliasing, or using an
alternate version of the program.  (This could do something like move
the file and record the original location somewhere, with a cron job
to clean out old entries.)

Some people want to deal with any file that is removed with an
"unlink" command.  With the microkernel approach, this requires file
system modifications, not kernel modifications.  (Actually, it could
be done one a user-by-user basis with modifications to the emulation
library, assuming HURD is keeping that aspect of Mach.)  One problem
with this idea is that file systems may optimize user actions in such
a way that data written to a file shortly before it is deleted will
never be written to disk.  But with the exception of temporary files,
this is probably a rare case.

So since HURD will support multiple file systems, it's just a matter
of someone taking the time to make the suggested change.

I haven't looked at it recently, but wouldn't a log-structured file
system naturally support undelete, at least until the segment
containing the file (or a portion of it) is cleaned?

--PC
--
  "First things first, but not necessarily in that order"  --The Doctor