Re: [PATCH] largefile support for accounting

[Jay Lan <jlan@engr.sgi.com>]

Yes, our CSA customers reported same problem. CSA already incoporated
same fix to our kernel module code. :)

Cheers,
  - jay


Peter Staubach wrote:
> Hi.
> 
> There is a problem in the accounting subsystem in the kernel can not
> correctly handle files larger than 2GB.  The output file containing
> the process accounting data can grow very large if the system is large
> enough and active enough.  If the 2GB limit is reached, then the system
> simply stops storing process accounting data.
> 
> Another annoying problem is that once the system reaches this 2GB limit,
> then every process which exits will receive a signal, SIGXFSZ.  This
> signal is generated because an attempt was made to write beyond the limit
> for the file descriptor.  This signal makes it look like every process
> has exited due to a signal, when in fact, they have not.
> 
> The solution is to add the O_LARGEFILE flag to the list of flags used
> to open the accounting file.  The rest of the accounting support is
> already largefile safe.
> 
> The changes were tested by constructing a large file (just short of 2GB),
> enabling accounting, and then running enough commands to cause the
> accounting data generated to increase the size of the file to 2GB.  Without
> the changes, the file grows to 2GB and the last command run in the test
> script appears to exit due a signal when it has not.  With the changes,
> things work as expected and quietly.
> 
> There are some user level changes required so that it can deal with
> largefiles, but those are being handled separately.
> 
> Signed-off-by: Peter Staubach <staubach@redhat.com>
> 
> 
> ------------------------------------------------------------------------
> 
> --- linux-2.6.12/kernel/acct.c.org	2005-06-17 15:48:29.000000000 -0400
> +++ linux-2.6.12/kernel/acct.c	2005-08-10 15:12:46.000000000 -0400
> @@ -220,7 +220,7 @@ asmlinkage long sys_acct(const char __us
>  			return (PTR_ERR(tmp));
>  		}
>  		/* Difference from BSD - they don't do O_APPEND */
> -		file = filp_open(tmp, O_WRONLY|O_APPEND, 0);
> +		file = filp_open(tmp, O_WRONLY | O_APPEND | O_LARGEFILE, 0);
>  		putname(tmp);
>  		if (IS_ERR(file)) {
>  			return (PTR_ERR(file));