On 2021/1/15 0:54, Michal Koutný wrote: > On Thu, Jan 14, 2021 at 10:08:19PM +0800, chenzhou <chenzhou10@xxxxxxxxxx> wrote: >> In this case, at the beginning of function check_cgroupfs_options(), the mask >> ctx->subsys_mask will be 0. And if we mount without 'none' and 'name=' options, >> then in check_cgroupfs_options(), the flag ctx->all_ss will be set, that is, select all the subsystems. > But even then, the line > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/kernel/cgroup/cgroup-v1.c?h=v5.11-rc3#n1012 > would select only 'enabled' controllers, wouldn't it? Yeah, this will select all enabled controllers, but which doesn't the behavior we want. I think the case should return error with information "Disabled controller xx" rather than attaching all the other enabled controllers. For example, boot with cgroup_no_v1=cpu, and then mount with "mount -t cgroup -o cpu cpu /sys/fs/cgroup/cpu", then all enabled controllers will be attached expect cpu. > > It's possible I missed something but if this means that cgroup_no_v1= > doesn't hold to its expectations, I'd suggest adding proper Fixes: tag > to the patch. See above. Just the mount behavior isn't what we what. The behavior was changed since commit f5dfb5315d34 ("cgroup: take options parsing into ->parse_monolithic()"), will add this as Fixes. Thanks, Chen Zhou > > Thanks, > Michal
