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Date: Tue, 18 Feb 2014 14:20:29 -0800
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Subject: Re: [PATCH 03/11] vfs: Don't allow overwriting mounts in the current
 mount namespace
From: Linus Torvalds <torvalds@linux-foundation.org>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>, Al Viro <viro@zeniv.linux.org.uk>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Linux-Fsdevel <linux-fsdevel@vger.kernel.org>,
        Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Andy Lutomirski <luto@amacapital.net>, Rob Landley <rob@landley.net>,
        Christoph Hellwig <hch@infradead.org>, Karel Zak <kzak@redhat.com>,
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On Tue, Feb 18, 2014 at 1:28 PM, Eric W. Biederman
<ebiederm@xmission.com> wrote:
>
>>
>> Minor nit: return value of any is_* function is either true or false, so why not
>> declare it bool?
>
> Because I am working on the core of the kernel and C compilers do weird
> things with bool variables (storing them in bytes...).  I expected a
> type that the C compiler does not do weird things with would be more
> readily received on a path whose performance people are interested in.

Yeah, I have to say that I'm not a huge fan of "bool". It has some odd
properties, especially in memory (ie as a structure member).

For this kind of function return value it actually tends to work very
well, and in fact often generates slightly better code than "int". So
I don't _hate_ bool, and we've certainly had a lot more use creep in
lately, but I also don't really see "bool" as much of an upside.

             Linus