Re: [PATCH 2/5] btrfs: add helpers to get inode from page/folio pointers

[David Sterba <dsterba@suse.cz>]

On Wed, Jan 31, 2024 at 09:33:58AM +0000, Johannes Thumshirn wrote:
> On 30.01.24 20:29, David Sterba wrote:
> > On Tue, Jan 30, 2024 at 11:42:30AM +0000, Johannes Thumshirn wrote:
> >> On 29.01.24 19:33, David Sterba wrote:
> >>> diff --git a/fs/btrfs/misc.h b/fs/btrfs/misc.h
> >>> index 40f2d9f1a17a..8be09234c575 100644
> >>> --- a/fs/btrfs/misc.h
> >>> +++ b/fs/btrfs/misc.h
> >>> @@ -8,6 +8,9 @@
> >>>    #include <linux/math64.h>
> >>>    #include <linux/rbtree.h>
> >>>    
> >>> +#define page_to_inode(page)	BTRFS_I((page)->mapping->host)
> >>> +#define folio_to_inode(folio)	BTRFS_I((folio)->mapping->host)
> >>> +
> >>
> >> Why are you using a macro instead of an inline function here?
> > 
> > As said in the changelog so we don't have to include headers with full
> > definitions of page, folio, fs_info, ...
> > 
> >> Shouldn't inline function give us a bit more type safety, or are
> >> compilers smart enough nowadays?
> > 
> > Yes type safety would be good but then it can't be an inline without
> > bloating misc.h (and the making include cycles).
> 
> I personally would've put them into fs.h anyways.

Right, that's more suitable, misc.h is for all the non-fs things.