On Wed, May 28, 2008 at 10:02:01AM -0600, Andreas Dilger wrote: > On May 27, 2008 13:31 -0700, Joel Becker wrote: > > Provide generic_fiemap_fiecount() that does the operation in > > terms of ->fiemap(). Then filesystems like ocfs2 can just do .fiecount > > = generic_fiemap_fiecount. > > I agree with Christoph that it seems a bit overloaded when done > > as a special case of FIEMAP. > > The question is whether there are any (or many) filesystems that will NOT > implement ->fiecount() as a wrapper of ->fiemap()? At that point the > "simplification" of the API means that there is actually more code and > layers being called for the simple version. > > I'm not saying I'm against having a FIECOUNT ioctl, we're probably just > going to use an updated filefrag like everyone else, but it doesn't seem > like a net reduction in code anywhere. It's not about net reduction of code. It's about a readable and understandable interface. "Pass this array of extent structures we'll ignore if you set this special flag" is pretty ugly. Calling FIECOUNT separately is nice. How it is implemented in the kernel is a whole 'nother ball of wax - maybe we don't have ->fiecount() and always implement FIECOUNT in terms of a ->fiemap() walk. Doesn't matter. Joel -- "Hey mister if you're gonna walk on water, Could you drop a line my way?" Joel Becker Principal Software Developer Oracle E-mail: joel.becker@xxxxxxxxxx Phone: (650) 506-8127 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
