Re: [PATCH 2/2] ext4: Fix compat EXT4_IOC_ADD_GROUP

[tytso@mit.edu]

On Thu, May 20, 2010 at 10:41:20PM -0600, Andreas Dilger wrote:
> On 2010-05-20, at 17:34, Ben Hutchings wrote:
> > struct ext4_new_group_input needs to be converted because u64 has
> > only 32-bit alignment on some 32-bit architectures, notably i386.
> 
> Sigh, it would have been nice to catch this when ext4_new_group_input was first created.
> 
> I don't mind fixing the kernel, since this is clearly broken.
> However, we may as well go ahead and declare a new struct
> ext4_new_group_input that has the right alignment, rename and
> deprecate the old one (have resize2fs prefer the new one if
> available) and take the old one out in a few years.  I hate this
> business of keeping around old cruft like this forever.

Well, in the long run we need a new ioctl which is compatible with
flex_bg, which means doing multiple groups at once, and letting the
kernel do much more of the work of selecting the block and inode
numbers.  And of course to support 2**64 blocks we need to support the
meta_bg style of resizing.  So we need to do some thinking about how
to support resizing in the long-term anyway.

   	   	       	   	     - Ted