Commit fa7e439c authored by Michal Koutný's avatar Michal Koutný Committed by Tejun Heo
Browse files

cgroup: Homogenize cgroup_get_from_id() return value 



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 d4ccaf58 ("bpf: Introduce cgroup
iter") that would use NULL instead of proper error handling in
d4ccaf58 ("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: d4ccaf58 ("bpf: Introduce cgroup iter")
Signed-off-by: default avatarMichal Koutný <mkoutny@suse.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 4534dee9

block/blk-cgroup-fc-appid.c

+2 −2
Original line number Diff line number Diff line
@@ -19,8 +19,8 @@ int blkcg_set_fc_appid(char *app_id, u64 cgrp_id, size_t app_id_len) 
		return -EINVAL;



	cgrp = cgroup_get_from_id(cgrp_id);

	if (!cgrp)

		return -ENOENT;

	if (IS_ERR(cgrp))

		return PTR_ERR(cgrp);

	css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);

	if (!css) {

		ret = -ENOENT;

include/linux/cgroup.h

+0 −5
Original line number Diff line number Diff line
@@ -750,11 +750,6 @@ static inline bool task_under_cgroup_hierarchy(struct task_struct *task, 


static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen)

{}



static inline struct cgroup *cgroup_get_from_id(u64 id)

{

	return NULL;

}

#endif /* !CONFIG_CGROUPS */



#ifdef CONFIG_CGROUPS

kernel/cgroup/cgroup.c

+2 −2
Original line number Diff line number Diff line
@@ -6005,7 +6005,7 @@ void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) 
/*

 * cgroup_get_from_id : get the cgroup associated with cgroup id

 * @id: cgroup id

 * On success return the cgrp, on failure return NULL

 * On success return the cgrp or ERR_PTR on failure

 * Only cgroups within current task's cgroup NS are valid.

 */

struct cgroup *cgroup_get_from_id(u64 id)
@@ -6037,7 +6037,7 @@ struct cgroup *cgroup_get_from_id(u64 id) 
		cgrp = NULL;

	}

out:

	return cgrp;

	return cgrp ?: ERR_PTR(-ENOENT);

}

EXPORT_SYMBOL_GPL(cgroup_get_from_id);

mm/memcontrol.c

+2 −2
Original line number Diff line number Diff line
@@ -5110,8 +5110,8 @@ struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino) 
	struct mem_cgroup *memcg;



	cgrp = cgroup_get_from_id(ino);

	if (!cgrp)

		return ERR_PTR(-ENOENT);

	if (IS_ERR(cgrp))

		return PTR_ERR(cgrp);



	css = cgroup_get_e_css(cgrp, &memory_cgrp_subsys);

	if (css)