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From: "Russ Cox" <rsc@plan9.bell-labs.com>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] [RFC] sysremove()/sysmount() race
Date: Mon,  5 Mar 2001 03:54:09 -0500	[thread overview]
Message-ID: <20010305085413.703C6199F1@mail.cse.psu.edu> (raw)

I don't see what the problem is.  Namec gets you a
chan, either pre- or post-mount.  If you get in
before the remove, the mount succeeds but attempts
to access the mount point fail.  If you get in after
the remove, the mount itself fails.  

More generally, I don't see how this is any different
than some other user (on a different machine entirely)
removing the mount point at the same time you do a mount.
You get exactly the same behavior, which means the kernel
is probably doing the right thing.

Backing up even more, it's not really any different
than doing chmod 0 on some directory -- processes with
a working directory deeper than that will continue to
access files, but you won't be able to evaluate any 
rooted names that go through that directory.

In all cases, there's no way to prevent it from happening,
and the behavior is entirely understandable.

Russ


             reply	other threads:[~2001-03-05  8:54 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-03-05  8:54 Russ Cox [this message]
  -- strict thread matches above, loose matches on Subject: below --
2001-03-05  8:37 Alexander Viro

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