Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-11 06:31:49 +00:00
Code Issues Packages Projects Releases Wiki Activity

cgroup: Add cgroup_get_from_fd

Browse Source 
Add a helper function to get a cgroup2 from a fd.  It will be
stored in a bpf array (BPF_MAP_TYPE_CGROUP_ARRAY) which will
be introduced in the later patch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Alexei Starovoitov <ast@fb.com>
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>
This commit is contained in:
Martin KaFai Lau 2016-06-30 10:28:42 -07:00 committed by David S. Miller
parent 6bd3847bdc
commit 1f3fe7ebf6
2 changed files with 36 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/cgroup.h
View File

@ -87,6 +87,7 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
struct cgroup_subsys *ss);
struct cgroup *cgroup_get_from_path(const char *path);
struct cgroup *cgroup_get_from_fd(int fd);
int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);
int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);

35
kernel/cgroup.c
View File

@ -62,6 +62,7 @@
#include <linux/proc_ns.h>
#include <linux/nsproxy.h>
#include <linux/proc_ns.h>
#include <linux/file.h>
#include <net/sock.h>
/*
@ -6209,6 +6210,40 @@ struct cgroup *cgroup_get_from_path(const char *path)
}
EXPORT_SYMBOL_GPL(cgroup_get_from_path);
/**
* cgroup_get_from_fd - get a cgroup pointer from a fd
* @fd: fd obtained by open(cgroup2_dir)
*
* Find the cgroup from a fd which should be obtained
* by opening a cgroup directory. Returns a pointer to the
* cgroup on success. ERR_PTR is returned if the cgroup
* cannot be found.
*/
struct cgroup *cgroup_get_from_fd(int fd)
{
struct cgroup_subsys_state *css;
struct cgroup *cgrp;
struct file *f;
f = fget_raw(fd);
if (!f)
return ERR_PTR(-EBADF);
css = css_tryget_online_from_dir(f->f_path.dentry, NULL);
fput(f);
if (IS_ERR(css))
return ERR_CAST(css);
cgrp = css->cgroup;
if (!cgroup_on_dfl(cgrp)) {
cgroup_put(cgrp);
return ERR_PTR(-EBADF);
}
return cgrp;
}
EXPORT_SYMBOL_GPL(cgroup_get_from_fd);
/*
* sock->sk_cgrp_data handling. For more info, see sock_cgroup_data
* definition in cgroup-defs.h.