[PATCH V4 07/12] cgroup: export fhandle info for a cgroup
From: Shaohua Li <shli@kernel.org>
Date: 2017-06-28 16:32:24
Also in:
lkml
Subsystem:
control group (cgroup), the rest · Maintainers:
Tejun Heo, Johannes Weiner, Michal Koutný, Linus Torvalds
From: Shaohua Li <redacted> Add an API to export cgroup fhandle info. We don't export a full 'struct file_handle', there are unrequired info. Sepcifically, cgroup is always a directory, so we don't need a 'FILEID_INO32_GEN_PARENT' type fhandle, we only need export the inode number and generation number just like what generic_fh_to_dentry does. And we can avoid the overhead of getting an inode too, since kernfs_node_id (ino and generation) has all the info required. Signed-off-by: Shaohua Li <redacted> --- include/linux/cgroup.h | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 30c6877..52ef9a6 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h@@ -609,6 +609,10 @@ static inline void cgroup_kthread_ready(void) current->no_cgroup_migration = 0; } +static inline union kernfs_node_id *cgroup_get_kernfs_id(struct cgroup *cgrp) +{ + return &cgrp->kn->id; +} #else /* !CONFIG_CGROUPS */ struct cgroup_subsys_state;
@@ -631,6 +635,10 @@ static inline int cgroup_init_early(void) { return 0; } static inline int cgroup_init(void) { return 0; } static inline void cgroup_init_kthreadd(void) {} static inline void cgroup_kthread_ready(void) {} +static inline union kernfs_node_id *cgroup_get_kernfs_id(struct cgroup *cgrp) +{ + return NULL; +} static inline bool task_under_cgroup_hierarchy(struct task_struct *task, struct cgroup *ancestor)
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2.9.3