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Subject: Re: [RFC v4][PATCH 9/9] File descriprtors (restore)
From: Dave Hansen <dave@linux.vnet.ibm.com>
To: Oren Laadan <orenl@cs.columbia.edu>
Cc: containers@lists.linux-foundation.org, jeremy@goop.org, arnd@arndb.de,
       linux-kernel@vger.kernel.org
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Date: Wed, 10 Sep 2008 09:09:29 -0700
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On Tue, 2008-09-09 at 21:49 -0400, Oren Laadan wrote:
> 
> Dave Hansen wrote:
> > On Tue, 2008-09-09 at 03:42 -0400, Oren Laadan wrote:
> >> +static int cr_close_all_fds(struct files_struct *files)
> >> +{
> >> +       int *fdtable;
> >> +       int n;
> >> +
> >> +       do {
> >> +               n = cr_scan_fds(files, &fdtable);
> >> +               if (n < 0)
> >> +                       return n;
> >> +               while (n--)
> >> +                       sys_close(fdtable[n]);
> >> +               kfree(fdtable);
> >> +       } while (n != -1);
> >> +
> >> +       return 0;
> >> +}
> > 
> > This needs to use an ERR_PTR().  It will save using the double-pointer.
> 
> I suppose you refer to the call to cr_scan_fds(): either 'fdtable'
> or 'n' will have to pass-by-reference. Is it that you prefer it to be
> 	fdtable = cr_scan_fds(files, &n);
> ?

I was misreading the use of 'n'.  Can you really not use close_files()
for this operation?  You'd need to add some locking around it, but I
think it does what you need here.

-- Dave