Re: [PATCH] Implement renaming for debugfs

[Jan Kara <jack@suse.cz>]

On Thu 03-05-07 17:16:02, Greg KH wrote:
> On Thu, May 03, 2007 at 11:54:52AM +0200, Jan Kara wrote:
> > On Tue 01-05-07 20:26:27, Greg KH wrote:
> > > On Mon, Apr 30, 2007 at 07:55:36PM +0200, Jan Kara wrote:
> > > >   Hello,
> > > > 
> > > >   attached patch implements renaming for debugfs. I was asked for this
> > > > feature by WLAN guys and I guess it makes sence (they have some debug info
> > > > in the directory identified by interface name and that can change...).
> > > > Could someone have a look at what I wrote whether it looks reasonable?
> > > > Thanks.
> > > > 
> > > > 								Honza
> > > > 
> > > > -- 
> > > > Jan Kara <jack@suse.cz>
> > > > SuSE CR Labs
> > > 
> > > > Implement debugfs_rename() to allow renaming files/directories in debugfs.
> > > 
> > > I think you are going to need more infrastructure here, the caller
> > > doesn't want to have to allocate a new dentry themselves, they just want
> > > to pass in the new filename :)
> >   Actually, I wanted the call to be in the spirit of other debugfs calls.
> > So we have for example:
> > void debugfs_remove(struct dentry *dentry)
> 
> That is because 'debugfs_create' returns a dentry.
> 
> > struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
> > etc.
> 
> Same here, you already have a dentry to place this directory into, _and_
> all the user needs to provide is a name for the new directory.  They
> don't ever create a dentry themselves, which is what your function
> required them to do.
> 
> Try using your function and you'll see what I mean :)
  I've tried it when testing the function :). The code looked like:
dir1 = debugfs_create_dir("dir1", NULL);
dir2 = debugfs_create_dir("dir2", NULL);
file1 = debugfs_create_file("file1", 0644, dir1, NULL, NULL);
file2 = debugfs_rename(dir1, file1, dir2, "new_name");
  No new dentries needed to be created...
  
> >   So it seemed to me that the interface with dentries was perfectly
> > appropriate... One possibility would be to take filename of a file to
> > rename instead of old_dentry. But dirs should IMHO remain to be dentries...
> 
> Sure, they should be dentries, but the caller should just provide a
> name.
  Hmm, I'm not sure I understand... So you prefer debugfs_rename() to be:

struct dentry *debugfs_rename(struct dentry *old_dir, const char *old_name,
	struct dentry *new_dir, const char *new_name);

  Right?
								Honza