From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dave Hansen <dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
Subject: Re: [RFC v14-rc][PATCH 09/23] Dump open file descriptors
Date: Fri, 20 Mar 2009 14:14:00 -0700
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To: Oren Laadan <orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org>
Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
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On Fri, 2009-03-20 at 16:55 -0400, Oren Laadan wrote:
> Dave Hansen wrote:
> > On Fri, 2009-03-20 at 14:47 -0400, Oren Laadan wrote:
> >> +       switch (inode->i_mode & S_IFMT) {
> >> +       case S_IFREG:
> >> +               fd_type = CR_FD_FILE;
> >> +               break;
> >> +       case S_IFDIR:
> >> +               fd_type = CR_FD_DIR;
> >> +               break;
> >> +       default:
> >> +               cr_hbuf_put(ctx, sizeof(*hh));
> >> +               return -EBADF;
> >> +       }
> > 
> > Why is there differentiation between files and directories?  Since we
> > deal with them in the same way, why bother adding this code everywhere
> > to make them distinct?
> 
> When we will handle unlinked files and unlinked directories, they will
> be handled differently.

This at *LEAST* needs a big fat comment.

... and unlinked files will be handled differently than normal files.
Can we cross that bridge when we come to it?  The abstraction that I
drew before in my patch was this:

	CR_FD_GENERIC

It means an fd the can be checkpointed/restored in a "generic" way,
namely "open()/lseek()", done.  Linked directories and linked files
share this attribute.  Unlinked files/directories do not.

Is it more important that we classify things based on the file/directory
properties, or how we handle them?

-- Dave