Cgroup id is user provided datum hence extend its return domain to
include possible error reason (similar to cgroup_get_from_fd()).
This change also fixes commit d4ccaf58a8 ("bpf: Introduce cgroup
iter") that would use NULL instead of proper error handling in
d4ccaf58a8 ("bpf: Introduce cgroup iter").
Additionally, neither of: fc_appid_store, bpf_iter_attach_cgroup,
mem_cgroup_get_from_ino (callers of cgroup_get_from_fd) is built without
CONFIG_CGROUPS (depends via CONFIG_BLK_CGROUP, direct, transitive
CONFIG_MEMCG respectively) transitive, so drop the singular definition
not needed with !CONFIG_CGROUPS.
Fixes: d4ccaf58a8 ("bpf: Introduce cgroup iter")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
No need to have these helpers inline. Also remove the stubs and just use
an IS_ENABLED for the get side (the set side already is only built
conditionlly).
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220420042723.1010598-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Michal Koutný