gfs2: Use container_of() for gfs2_glock(aspace)

Clang's structure layout randomization feature gets upset when it sees
struct address_space (which is randomized) cast to struct gfs2_glock.
This is due to seeing the mapping pointer as being treated as an array
of gfs2_glock, rather than "something else, before struct address_space":

In file included from fs/gfs2/acl.c:23:
fs/gfs2/meta_io.h:44:12: error: casting from randomized structure pointer type 'struct address_space *' to 'struct gfs2_glock *'
	return (((struct gfs2_glock *)mapping) - 1)->gl_name.ln_sbd;
		^

Replace the instances of open-coded pointer math with container_of()
usage, and update the allocator to match.

Some cleanups and conversion of gfs2_glock_get() and
gfs2_glock_dealloc() by Andreas.

Reported-by: kernel test robot <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]
Cc: Bob Peterson <[email protected]>
Cc: Andreas Gruenbacher <[email protected]>
Cc: Bill Wendling <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
Signed-off-by: Andreas Gruenbacher <[email protected]>

0 files changed, 0 insertions, 0 deletions