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    SubjectRe: dealing with excessive includes
    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.
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