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| author | Yafang Shao <laoar.shao@gmail.com> | 2023-10-29 06:14:32 +0000 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2023-11-09 13:25:47 -1000 |
| commit | aecd408b7e50742868b3305c24325a89024e2a30 (patch) | |
| tree | cef667773cd2ee6e9880ef19f62d0a02562dada6 /kernel/cgroup | |
| parent | 0008454e8fd30ed0017a9a35b8dd708f168931b8 (diff) | |
| download | lwn-aecd408b7e50742868b3305c24325a89024e2a30.tar.gz lwn-aecd408b7e50742868b3305c24325a89024e2a30.zip | |
cgroup: Add a new helper for cgroup1 hierarchy
A new helper is added for cgroup1 hierarchy:
- task_get_cgroup1
Acquires the associated cgroup of a task within a specific cgroup1
hierarchy. The cgroup1 hierarchy is identified by its hierarchy ID.
This helper function is added to facilitate the tracing of tasks within
a particular container or cgroup dir in BPF programs. It's important to
note that this helper is designed specifically for cgroup1 only.
tj: Use irsqsave/restore as suggested by Hou Tao <houtao@huaweicloud.com>.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Hou Tao <houtao@huaweicloud.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup')
| -rw-r--r-- | kernel/cgroup/cgroup-internal.h | 1 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup-v1.c | 34 |
2 files changed, 34 insertions, 1 deletions
diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index 5e17f01ced9f..520b90dd97ec 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -164,7 +164,6 @@ struct cgroup_mgctx { #define DEFINE_CGROUP_MGCTX(name) \ struct cgroup_mgctx name = CGROUP_MGCTX_INIT(name) -extern spinlock_t css_set_lock; extern struct cgroup_subsys *cgroup_subsys[]; extern struct list_head cgroup_roots; diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index 76db6c67e39a..04d11a7dd95f 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -1262,6 +1262,40 @@ int cgroup1_get_tree(struct fs_context *fc) return ret; } +/** + * task_get_cgroup1 - Acquires the associated cgroup of a task within a + * specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its + * hierarchy ID. + * @tsk: The target task + * @hierarchy_id: The ID of a cgroup1 hierarchy + * + * On success, the cgroup is returned. On failure, ERR_PTR is returned. + * We limit it to cgroup1 only. + */ +struct cgroup *task_get_cgroup1(struct task_struct *tsk, int hierarchy_id) +{ + struct cgroup *cgrp = ERR_PTR(-ENOENT); + struct cgroup_root *root; + unsigned long flags; + + rcu_read_lock(); + for_each_root(root) { + /* cgroup1 only*/ + if (root == &cgrp_dfl_root) + continue; + if (root->hierarchy_id != hierarchy_id) + continue; + spin_lock_irqsave(&css_set_lock, flags); + cgrp = task_cgroup_from_root(tsk, root); + if (!cgrp || !cgroup_tryget(cgrp)) + cgrp = ERR_PTR(-ENOENT); + spin_unlock_irqrestore(&css_set_lock, flags); + break; + } + rcu_read_unlock(); + return cgrp; +} + static int __init cgroup1_wq_init(void) { /* |