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Groups > comp.os.linux.development.apps > #202

Re: mmap unuseable for interactive application?

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Rainer Weikusat <rweikusat@mssgmbh.com> writes:
> Peter <excessphase@gmail.com> writes:
>> On Jul 18, 7:42 am, Rainer Weikusat <rweiku...@mssgmbh.com> wrote:
>>> 'Again' -- the solution to your 'problem' is to use the existing
>>> system facilities (which have existed 'since a long time') to
>>> coordinate use of shared resources by independent applications and not
>>> to whine about the fact that a lot of filesystems exists which don't
>>> work like the Windows file system.
>>
>> OK -- educate me!
>> What are the "existing system facilities" to prevent users from
>> accessing some file?
>
> cd /
> rm -rf *
>
> There is still some chance that a user might manage to access one of
> his own files while deletion is in progress but since this won't be
> reproducible, you can afterwards claim that it didn't happen.

For sake of completeness: Linux supports (and has supported for
years, I was already using this facility with 2.4) a mechanism called
'leases' for regular files (documented in fcntl(2)) which can be used
by a process in order to get notified when an otherwise unrelated
process is about to gain write or read access to a file (meaning, has
just called open w/ a specific mode) or has made a truncate call
conflicting with the lease and while this doesn't provide 'exclusive
open' it could be used to adapt a memory mapping of some file some
other process just messed with.

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Thread

mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-16 16:23 -0700
  Re: mmap unuseable for interactive application? Richard Kettlewell <rjk@greenend.org.uk> - 2011-07-17 10:52 +0100
    Re: mmap unuseable for interactive application? pacman@kosh.dhis.org (Alan Curry) - 2011-07-17 20:59 +0000
      Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-17 14:05 -0700
        Re: mmap unuseable for interactive application? Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-07-18 12:45 +0100
          Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-18 07:30 -0700
            Re: mmap unuseable for interactive application? Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-07-18 15:42 +0100
              Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-18 07:46 -0700
                Re: mmap unuseable for interactive application? Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-07-18 15:50 +0100
                Re: mmap unuseable for interactive application? Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-07-18 19:17 +0100
                Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-18 12:49 -0700
                Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-18 12:51 -0700
                Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-18 13:08 -0700
                Re: mmap unuseable for interactive application? Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-07-18 22:24 +0100
                Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-18 15:04 -0700
                Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-18 15:21 -0700
                Re: mmap unuseable for interactive application? Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-07-19 13:59 +0100
              Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-18 07:50 -0700
      Re: mmap unuseable for interactive application? Richard Kettlewell <rjk@greenend.org.uk> - 2011-07-18 10:59 +0100
        Re: mmap unuseable for interactive application? pacman@kosh.dhis.org (Alan Curry) - 2011-07-18 20:14 +0000
  Re: mmap unuseable for interactive application? Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-07-17 19:40 +0100
    Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-17 14:11 -0700
      Re: mmap unuseable for interactive application? Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-07-18 12:46 +0100
    Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-17 14:13 -0700
      Re: mmap unuseable for interactive application? Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-07-18 13:49 +0100
        Re: mmap unuseable for interactive application? Peter <excessphase@gmail.com> - 2011-07-18 07:37 -0700

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