Re: [PATCH] fs: Add function declaration of simple_dname

[Matthew Wilcox]

On Wed, Aug 19, 2020 at 02:40:01PM +0300, Leon Romanovsky wrote:
> On Wed, Aug 19, 2020 at 12:34:24PM +0100, Matthew Wilcox wrote:
> > On Wed, Aug 19, 2020 at 11:32:59AM +0300, Leon Romanovsky wrote:
> > > From: Leon Romanovsky <leonro@xxxxxxxxxx>
> > >
> > > The simple_dname() is declared in internal header file as extern
> > > and this generates the following GCC warning.
> >
> > The fact that it's declared as extern doesn't matter.  You don't need
> > the change to internal.h at all.  The use of 'extern' on a function
> > declaration is purely decorative:
> >
> >   5 If the declaration of an identifier for a function has no
> >   storage-class specifier, its linkage is determined exactly as if it
> >   were declared with the storage-class specifier extern.
> 
> So why do we need to keep extern keyword if we use intenral.h directly?

We don't.  It's just personal preference.  I don't use extern keywords
on function declarations anywhere, but Al does and it's rude to change it.