Re: [PATCH 5/7] FS-Cache: Generic filesystem caching facility

[Andrew Morton <akpm@osdl.org>]

David Howells <dhowells@redhat.com> wrote:
>
> > That's your fourth implementation of kenter().  Maybe we
> > need <linux/dhowells.h>?
> 
> :-)
> 
> Maybe I should move my debugging macros into include/linux, but then everyone
> else would complain if their own versions weren't put in there, or would
> complain if they were forced to use mine.

The number of home-made debugging macro implementations we have is quite
demented.  Developing (and maintaining) a common set would be a good idea,
IMO.

> It doesn't actually produce very much code.
> 
> > Defining symbols which are owned by the Kconfig system isn't very nice.
> 
> Kconfig is still broken:
> 
> 	warthog>grep -r CONFIG_FSCACHE include/linux/autoconf.h 
> 	#define CONFIG_FSCACHE_MODULE 1
> 	warthog>
> 
> Modules that might depend on fscache need to know that it's there,

In theory, module A isn't supposed to care whether module B was configured,
because module B might be compiled separately, or dowloaded from elsewhere
or whatever.

> and having
> to double up every #if to detect both is stupid.
> 
> Would you suggest then:
> 
> 	#if defined(CONFIG_FSCACHE) || defined(CONFIG_FSCACHE_MODULE)
> 	#define FSCACHE_AVAILABLE 1
> 	#endif

yup.