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From: David Howells <dhowells@redhat.com>
In-Reply-To: <20160111225104.GO17997@ZenIV.linux.org.uk>
References: <20160111225104.GO17997@ZenIV.linux.org.uk> <1452547845-12039-1-git-send-email-chengang@emindsoft.com.cn>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: dhowells@redhat.com, chengang@emindsoft.com.cn, akpm@linux-foundation.org,
        nicolas.iooss_linux@m4x.org, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, Chen Gang <gang.chen.5i5j@gmail.com>
Subject: Re: [PATCH] fs: dcache: Use bool return value instead of int
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Date: Tue, 12 Jan 2016 00:33:37 +0000
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Al Viro <viro@ZenIV.linux.org.uk> wrote:

> > -static inline int d_unhashed(const struct dentry *dentry)
> > +static inline bool d_unhashed(const struct dentry *dentry)
> >  {
> >  	return hlist_bl_unhashed(&dentry->d_hash);
> >  }
> >  
> > -static inline int d_unlinked(const struct dentry *dentry)
> > +static inline bool d_unlinked(const struct dentry *dentry)
> >  {
> >  	return d_unhashed(dentry) && !IS_ROOT(dentry);
> >  }
> 
> > -static inline int simple_positive(struct dentry *dentry)
> > +static inline bool simple_positive(struct dentry *dentry)
> >  {
> >  	return d_really_is_positive(dentry) && !d_unhashed(dentry);
> >  }
> 
> And these three are harmless, but completely pointless...

gcc-5 does actually produce slightly smaller code when int returns are
replaced by bools under some circumstances within the kernel.

David