From mboxrd@z Thu Jan  1 00:00:00 1970
From: Orjan Friberg <of@flatfrog.com>
Subject: Re: CONFIG_PREEMPT and JFFS2 oops
Date: Wed, 25 Jan 2012 22:02:06 +0100
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On 01/25/2012 09:12 PM, Orjan Friberg wrote:
> I've boiled it down to whether CONFIG_PREEMPT (bug happens) or
> CONFIG_PREEMPT_VOLUNTARY (bug doesn't happen) is selected.

No, I haven't.  The problem disappeared only for

    while :; do dd if=/dev/zero of=file bs=800 count=1; done

That one-liner was boiled down from the following program, which still
oopses instantly:

    #include <stdio.h>
    #include <unistd.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <fcntl.h>

    int main()
    {
      int fd;
      struct stat st;
      char buf[800];

      do {
        unlink("file2");
        fd = open("file1", O_RDWR|O_CREAT|O_TRUNC, 0666);
        stat("file1", &st);
        lseek(fd, 0, SEEK_SET);
        write(fd, buf, 800);
        close(fd);
        rename("file1", "file2");
      } while (1);

      return 0;
    }


(Apologies for spamming.)


-- 
Orjan Friberg
FlatFrog Laboratories AB