Re: [PATCH 00/10] Cleanup unnecessary get_extent parameters

[David Sterba <dsterba@suse.cz>]

On Mon, Nov 06, 2017 at 11:26:54PM +0200, Nikolay Borisov wrote:
> 
> 
> On  6.11.2017 21:30, David Sterba wrote:
> > There are several functions that take a generic get_extent parameter, but not
> > all of them use it to distinguish between btree_get_exnent (for metadata) and
> > btrfs_get_extent (for data). This is namely extent_read_full_page and
> > __do_readpage.
> 
> I wonder whether we can do some similar collpasing withe some of the
> hooks we have i.e. readpage_end_io_hook (resp.
> btrfs_readpage_end_io_hook and btree_readpage_end_io_hook). All those
> callbacks don't necessarily help readability...

Some of the callbacks passed as parameters can be possibly pushed down
the callstack, the only difference is btree_inode vs file extents.
Instead of the uppper caller switch, the right function can be called
based on the inode number (btree_inode has 1).

Josef has some ideas/patches to get rid of the btree_inode completely so
cleaning up the callback might not be worth. There's still some
potential to reduce the arguments to the various callbacks, I have
patches for that. This is a relatively easy and safe so I would still
send them, as the btree_inode removal will be probably intrusive and the
ETA for such changes is unpredictable.