Re: PROBLEM: multiple mount of devices possible 2.4.0-test1 - 2.4.0-test13-pre4

From: Ton Hospel (linux-kernel@ton.iguana.be)
Date: Sat Dec 30 2000 - 22:18:21 EST

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    In article <Pine.GSO.4.21.0012301829190.4082-100000@weyl.math.psu.edu>,
            Alexander Viro <viro@math.psu.edu> writes:
    > On Sat, 30 Dec 2000, Ton Hospel wrote:
    >
    >> It should still need a special flag or something, since it's
    >> impossible for userspace to check this atomically.
    >
    > To check _what_? Having the same tree mounted in several places is
    > allowed. End of story. Atomicity of any kind is a non-issue - if you
    > have processes that do not cooperate and do random mounts you are
    > getting exactly what you are asking for.
    >

    I wasn't talking about mounting the same device on different mount points.
    If you ask for that, it's good that you nowadays you can get that (though
    even there it might be a good idea to let the filesystem say if it can
    support that or not)

    I was talking about avoiding that the same device gets multiple mounted
    at the SAME place, e.g. when doing mount -a, which is often used as a
    quick way to get the new entries in /etc/fstab

    That would also be no problem if there were a standard about e.g. always
    flocking /etc/mtab. But as far as I know there isn't such a standard.
    -
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