Re: Serious filesystem bug in linux [nevermind]

From: David Ashley (dash@xdr.com)
Date: Sun Jan 26 2003 - 19:42:10 EST


>On Sun, Jan 26, 2003 at 03:18:49PM -0800, David Ashley wrote:
>
>> -rw-r--r-- 1 root root 1965107636224 Jan 26 14:59 output1.iso
>
>You know about the Unix concept of files with holes?

No, but I can look into it. There is definitely some bug in my program
but I wouldn't expect this behaviour. So if I seek way the hell out
to nowhere, do a write, I'll have a file of the total amount I've skipped
over?

I just wrote a test program and it did exactly this. Thanks!

Here is the program
#define _LARGEFILE64_SOURCE
#include <fcntl.h>
#include <unistd.h>

main()
{
int fd;
char buff[32];
        fd=open("/tmp/crazybigfile",O_RDWR|O_CREAT|O_TRUNC|O_LARGEFILE,0644);
        lseek64(fd,1000000000000ll,SEEK_SET);
        write(fd,buff,32);
        close(fd);

}

Live and learn. Sorry for the alarm!

-Dave
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