From: Matthew Wilcox <matthew@wil.cx>
To: Linus Torvalds <torvalds@osdl.org>
Cc: Al Viro <viro@ftp.linux.org.uk>,
Alexey Dobriyan <adobriyan@gmail.com>,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org
Subject: Re: dealing with excessive includes
Date: Wed, 18 Oct 2006 09:13:19 -0600 [thread overview]
Message-ID: <20061018151319.GQ22289@parisc-linux.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0610180759070.3962@g5.osdl.org>
On Wed, Oct 18, 2006 at 08:04:24AM -0700, Linus Torvalds wrote:
> On Wed, 18 Oct 2006, Al Viro wrote:
> >
> > +#define lock_super(x) do { \
> > + struct super_block *sb = x; \
> > + get_fs_excl(); \
> > + mutex_lock(&sb->s_lock); \
> > +} while(0)
>
> Don't do this. The "x" passed in may be "sb", and then you end up with
> bogus code.
For this one, I see a third way:
#define lock_super(sb) do { \
get_fs_excl(); \
mutex_lock(&(sb)->s_lock); \
} while (0)
It does have the disadvantage that you can pass *anything* that has
an s_lock field in ... but I don't think that's a very likely thing
to happen.
Or you could use _sb as the local variable, since it's a reserved
identifier.
next prev parent reply other threads:[~2006-10-18 15:13 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-17 0:50 [RFC] typechecking for get_unaligned/put_unaligned Al Viro
2006-10-17 1:50 ` Linus Torvalds
2006-10-17 4:37 ` Al Viro
2006-10-17 15:12 ` Bogus deps checking (was Re: [RFC] typechecking for get_unaligned/put_unaligned) Ray Lehtiniemi
2006-10-17 15:24 ` [RFC] typechecking for get_unaligned/put_unaligned Linus Torvalds
2006-10-18 4:40 ` dealing with excessive includes Al Viro
2006-10-18 9:19 ` Alexey Dobriyan
2006-10-18 9:31 ` Al Viro
2006-10-18 10:00 ` Alexey Dobriyan
2006-10-18 17:42 ` Al Viro
2006-10-18 21:48 ` Alexey Dobriyan
2006-10-18 15:04 ` Linus Torvalds
2006-10-18 15:13 ` Matthew Wilcox [this message]
2006-10-18 16:06 ` Al Viro
2006-10-18 16:32 ` Linus Torvalds
2006-10-18 17:44 ` Al Viro
2006-10-19 16:23 ` Al Viro
2006-10-19 18:24 ` Andreas Gruenbacher
2006-10-20 0:53 ` Al Viro
2006-10-20 0:57 ` Al Viro
2006-10-20 12:43 ` Matthew Wilcox
2006-10-20 0:58 ` Al Viro
2006-10-20 0:59 ` Al Viro
2006-10-20 1:02 ` Al Viro
2006-10-20 4:35 ` Randy Dunlap
2006-10-20 9:26 ` Stefan Richter
2006-10-20 16:13 ` Randy Dunlap
2006-10-20 17:51 ` Stefan Richter
2006-10-22 17:58 ` Geert Uytterhoeven
2006-10-22 22:59 ` Andi Kleen
2006-10-23 8:29 ` Geert Uytterhoeven
2006-10-23 16:09 ` Linus Torvalds
2006-10-23 16:13 ` Geert Uytterhoeven
2006-10-23 16:31 ` Linus Torvalds
2006-10-23 16:52 ` Geert Uytterhoeven
2006-10-23 17:05 ` Linus Torvalds
2006-10-23 0:31 ` Matthew Wilcox
2006-10-23 0:42 ` Andi Kleen
2006-10-23 1:08 ` Matthew Wilcox
2006-10-23 1:31 ` Andi Kleen
2006-10-23 1:36 ` Matthew Wilcox
2006-10-23 1:41 ` Andi Kleen
2006-10-23 8:34 ` Geert Uytterhoeven
2006-10-23 1:48 ` Randy Dunlap
2006-10-23 1:49 ` Nick Piggin
2006-10-23 6:34 ` Stefan Richter
2006-10-18 16:15 ` Jan Engelhardt
2006-10-18 16:21 ` Matthew Wilcox
2006-10-18 5:42 ` [RFC] typechecking for get_unaligned/put_unaligned Dave Jones
2006-10-18 6:05 ` Al Viro
2006-10-19 16:52 ` Denis Vlasenko
2006-10-19 16:58 ` Al Viro
2006-10-17 9:04 ` David Howells
2006-10-17 15:28 ` Linus Torvalds
-- strict thread matches above, loose matches on Subject: below --
2006-10-28 15:24 dealing with excessive includes Tim Schmielau
2006-10-30 10:45 Al Viro
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