Re: [PATCH 21/21] hfsplus: remove can_set_xattr

[Christoph Hellwig <hch@infradead.org>]

On Tue, Dec 24, 2013 at 10:41:44AM +0400, Vyacheslav Dubeyko wrote:
> > -
> > -	if (strncmp(name, XATTR_MAC_OSX_PREFIX,
> > -				XATTR_MAC_OSX_PREFIX_LEN) == 0)
> > -		name += XATTR_MAC_OSX_PREFIX_LEN;
> 
> Removing this skipping of virtual "osx." prefix means that you save it
> on volume. But such action means volume corruption really. Because HFS+
> volume hasn't such prefixes for xattrs in AttributesFile. Usually,
> special xattrs has prefix "com.apple.*" but others haven't any prefix
> and can be named as you want. So, I think that it is not correct
> modification.

With my patch applied we don't add the prefix that later gets stripped
in the first place:

 - hfsplus_osx_setxattr gets called without the prefix from the VFS code
 - the code to add the prefix in hfsplus_osx_setxattr is removed by the
   patch
 - the code to remove it again in __hfsplus_setxattr is removed as well

Because of the way the handlers work no other caller of
__hfsplus_setxattr should ever have a name with the osx prefix.

Same for the getxattr side.