Possible race in the filesystem code (softupdates) ?

From: Martin Blapp (mb_at_imp.ch)
Date: 04/04/04

  • Next message: Ivan Voras: "Re: Possible race in the filesystem code (softupdates) ?"
    Date: Sun, 4 Apr 2004 22:55:59 +0200 (CEST)
    To: current@freebsd.org
    
    

    Hi,

    During testing I found that the following procedure is pretty dangerous
    and leads sometimes to a panic():

    cd /usr/ports/editors/openoffice-1.1
    make patch
    mv work work.old
    rm -rfd work.old &
    make patch &
    find work.old > /dev/null 2>&1

    The filesystem was mounted with softupdates.

    I'm trying to reproduce it tomorrow for a useful dump. I had it happen twice but
    was not able to take any notices because it happenend on a productive server.
    I can exclude any hardware problems. We use current from a week ago.

    Find(8) seems to trigger that bug while we are deleting this really huge
    work dir with ~200000 files in it and doing a stat on it at the same
    time.

    I'd call the bug pretty serious. I'll post more info after I got one
    more panic.

    Some other thing that scares me is that reading a filesystem with many many
    little files (as the openoffice work dir) slows down all IO operations. At
    BSDCon Matt Dillon talked to me about this issue and about his plan to solve it.

    Matt, did you make any progress here ? It is really scaring how slow UFS is
    in this area.

    Martin
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  • Next message: Ivan Voras: "Re: Possible race in the filesystem code (softupdates) ?"

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