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| author |   Sargun Dhillon <sargun@sargun.me> | 2016-08-12 08:56:40 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2016-08-12 21:49:41 -0700 |
| commit | aed704b7a634954dc28fe5c4b49db478cf2d96b7 (patch) | |
| tree | 4999afa6e46efcf5903f967a1dd737375de6b2cc /include/linux/cgroup.h | |
| parent | Merge tag 'batadv-next-for-davem-20160812' of git://git.open-mesh.org/linux-merge (diff) | |
| download | linux-dev-aed704b7a634954dc28fe5c4b49db478cf2d96b7.tar.xz linux-dev-aed704b7a634954dc28fe5c4b49db478cf2d96b7.zip | |
cgroup: Add task_under_cgroup_hierarchy cgroup inline function to headers
This commit adds an inline function to cgroup.h to check whether a given
task is under a given cgroup hierarchy. This is to avoid having to put
ifdefs in .c files to gate access to cgroups. When cgroups are disabled
this always returns true.
Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 984f73b719a9..a4414a11eea7 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -497,6 +497,23 @@ static inline bool cgroup_is_descendant(struct cgroup *cgrp, return cgrp->ancestor_ids[ancestor->level] == ancestor->id; } +/** + * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry + * @task: the task to be tested + * @ancestor: possible ancestor of @task's cgroup + * + * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor. + * It follows all the same rules as cgroup_is_descendant, and only applies + * to the default hierarchy. + */ +static inline bool task_under_cgroup_hierarchy(struct task_struct *task, + struct cgroup *ancestor) +{ + struct css_set *cset = task_css_set(task); + + return cgroup_is_descendant(cset->dfl_cgrp, ancestor); +} + /* no synchronization, the result can only be used as a hint */ static inline bool cgroup_is_populated(struct cgroup *cgrp) { @@ -557,6 +574,7 @@ static inline void pr_cont_cgroup_path(struct cgroup *cgrp) #else /* !CONFIG_CGROUPS */ struct cgroup_subsys_state; +struct cgroup; static inline void css_put(struct cgroup_subsys_state *css) {} static inline int cgroup_attach_task_all(struct task_struct *from, @@ -574,6 +592,11 @@ static inline void cgroup_free(struct task_struct *p) {} static inline int cgroup_init_early(void) { return 0; } static inline int cgroup_init(void) { return 0; } +static inline bool task_under_cgroup_hierarchy(struct task_struct *task, + struct cgroup *ancestor) +{ + return true; +} #endif /* !CONFIG_CGROUPS */ /* |