On 01/07/2014 04:52 PM, Mike Snitzer wrote: > On Tue, Jan 07 2014 at 5:39am -0500, > Joe Thornber <thornber@xxxxxxxxxx> wrote: > >> On Mon, Jan 06, 2014 at 10:53:28PM -0500, Mikulas Patocka wrote: >>> Remove pointless comparison in dm_get_from_kobject. The comparison is >>> always true and the compiler optimizes it out anyway. >>>gmane.linux.kernel.device-mapper.devel >>> Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> >>> >>> --- >>> drivers/md/dm.c | 2 -- >>> 1 file changed, 2 deletions(-) >>> >>> Index: linux-3.13-rc7/drivers/md/dm.c >>> =================================================================== >>> --- linux-3.13-rc7.orig/drivers/md/dm.c 2014-01-07 01:28:27.000000000 +0100 >>> +++ linux-3.13-rc7/drivers/md/dm.c 2014-01-07 01:28:39.000000000 +0100 >>> @@ -2922,8 +2922,6 @@ struct mapped_device *dm_get_from_kobjec >>> struct mapped_device *md; >>> >>> md = container_of(kobj, struct mapped_device, kobj); >>> - if (&md->kobj != kobj) >>> - return NULL; >> >> What were they trying to check? The compiler? >> > > Milan's commit 784aae735d, and the current dm.c code, offers this > comment above dm_get_from_kobject: > > /* > * struct mapped_device should not be exported outside of dm.c > * so use this check to verify that kobj is part of md structure > */ > > I'm lacking the vision to _know_ why the kobject would suddenly be > outside of the mapped_device without us knowing via code change.. > > The check does seem overly cautious/useless (if we remove it the above > comment should be removed too). Yes, please remove both :) The check doesn't make sense. I think it is just relict of some experiments before I committed this simple embedded sysfs kobj handling (there were always problems like the missing .release function you are just solving in other thread). Milan -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
