Re: [PATCH v2 09/28] libext2fs: handle inline data in dir iterator function

[Zheng Liu <gnehzuil.liu@gmail.com>]

On Tue, Dec 03, 2013 at 09:10:25PM -0800, Darrick J. Wong wrote:
> On Wed, Dec 04, 2013 at 12:57:36PM +0800, Zheng Liu wrote:
> > On Tue, Dec 03, 2013 at 02:13:49PM -0800, Darrick J. Wong wrote:
> > > On Tue, Dec 03, 2013 at 08:11:36PM +0800, Zheng Liu wrote:
> > > > From: Zheng Liu <wenqing.lz@taobao.com>
> > > > 
> > > > Inline_data is handled in dir iterator because a lot of commands use
> > > > this function to traverse directory entries in debugfs.  We need to
> > > > handle inline_data individually because inline_data is saved in two
> > > > places.  One is in i_block, and another is in ibody extended attribute.
> > > > 
> > > > After applied this commit, the following commands in debugfs can
> > > > support the inline_data feature:
> > > > 	- cd
> > > > 	- chroot
> > > > 	- link*
> > > > 	- ls
> > > > 	- ncheck
> > > > 	- pwd
> > > > 	- unlink
> > > > 
> > > > * TODO: Inline_data doesn't expand to ibody extended attribute because
> > > >   link command doesn't handle DIR_NO_SPACE error until now.  But if we
> > > >   have already expanded inline data to ibody ea area, link command can
> > > >   occupy this space.
> > > 
> > > A patch for this TODO is coming, right?
> > 
> > TBH, I don't have a patch for this because I don't know why ext2fs_link
> > doesn't handle DIR_NO_SPACE error.  So I will try to fix it later.
> 
> Yeah, it's sort of annoying that it doesn't do that.  You might notice that
> fuse2fs will detect that error code, call ext2fs_expand_dir(), and try again.
> On the other hand, none of the other programs do that...
> 
> ...it's not difficult to change ext2fs_link() to do that, though.
> 
> again:
> 
> /* link_proc magic... */
> 
> if (!ls.done && !not_again) {
> 	ext2fs_expand_dir(fs, dir...);
> 	not_again = 1;
> 	goto again;
> }
> 
> Hmm.  That /is/ easy to fix.  I might as well fix that.

I don't think we should fix it in ext2fs_link because I am afraid that
we could break the client that has handled this problem.  So I am plan
to fix it in make_link().  What do you think?

                                                - Zheng