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Date: Tue, 20 Dec 2016 16:08:24 -0500
From: Tejun Heo <tj@...nel.org>
To: lizefan@...wei.com, hannes@...xchg.org
Cc: linux-kernel@...r.kernel.org, cgroups@...r.kernel.org,
kernel-team@...com, Tejun Heo <tj@...nel.org>
Subject: [PATCH 5/8] cgroup: separate out cgroup1_kf_syscall_ops
Currently, cgroup_kf_syscall_ops is shared by v1 and v2 and the
specific methods test the version and take different actions. Split
out v1 functions and put them in cgroup1_kf_syscall_ops and remove the
now unnecessary explicit branches in specific methods.
Signed-off-by: Tejun Heo <tj@...nel.org>
---
kernel/cgroup/cgroup-internal.h | 4 ++--
kernel/cgroup/cgroup-v1.c | 11 ++---------
kernel/cgroup/cgroup.c | 40 ++++++++++++++++++++++++++--------------
3 files changed, 30 insertions(+), 25 deletions(-)
diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h
index d86fbbc..7b8182e 100644
--- a/kernel/cgroup/cgroup-internal.h
+++ b/kernel/cgroup/cgroup-internal.h
@@ -93,8 +93,8 @@ extern const struct file_operations proc_cgroupstats_operations;
bool cgroup_ssid_no_v1(int ssid);
void cgroup_pidlist_destroy_all(struct cgroup *cgrp);
-int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
- const char *new_name_str);
+int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
+ const char *new_name_str);
void cgroup_release_agent(struct work_struct *work);
void check_for_release(struct cgroup *cgrp);
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 7af745a..0b2c24f 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -800,8 +800,8 @@ void cgroup_release_agent(struct work_struct *work)
/*
* cgroup_rename - Only allow simple rename of directories in place.
*/
-int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
- const char *new_name_str)
+int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
+ const char *new_name_str)
{
struct cgroup *cgrp = kn->priv;
int ret;
@@ -812,13 +812,6 @@ int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
return -EIO;
/*
- * This isn't a proper migration and its usefulness is very
- * limited. Disallow on the default hierarchy.
- */
- if (cgroup_on_dfl(cgrp))
- return -EPERM;
-
- /*
* We're gonna grab cgroup_mutex which nests outside kernfs
* active_ref. kernfs_rename() doesn't require active_ref
* protection. Break them before grabbing cgroup_mutex.
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 6225c4b..f1b71fb 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1234,6 +1234,7 @@ struct cgroup *task_cgroup_from_root(struct task_struct *task,
* update of a tasks cgroup pointer by cgroup_attach_task()
*/
+static struct kernfs_syscall_ops cgroup1_kf_syscall_ops;
static struct kernfs_syscall_ops cgroup_kf_syscall_ops;
static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
@@ -1568,16 +1569,15 @@ static int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
return len;
}
-static int cgroup_show_options(struct seq_file *seq, struct kernfs_root *kf_root)
+static int cgroup1_show_options(struct seq_file *seq, struct kernfs_root *kf_root)
{
struct cgroup_root *root = cgroup_root_from_kf(kf_root);
struct cgroup_subsys *ss;
int ssid;
- if (root != &cgrp_dfl_root)
- for_each_subsys(ss, ssid)
- if (root->subsys_mask & (1 << ssid))
- seq_show_option(seq, ss->legacy_name, NULL);
+ for_each_subsys(ss, ssid)
+ if (root->subsys_mask & (1 << ssid))
+ seq_show_option(seq, ss->legacy_name, NULL);
if (root->flags & CGRP_ROOT_NOPREFIX)
seq_puts(seq, ",noprefix");
if (root->flags & CGRP_ROOT_XATTR)
@@ -1738,18 +1738,13 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
return 0;
}
-static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)
+static int cgroup1_remount(struct kernfs_root *kf_root, int *flags, char *data)
{
int ret = 0;
struct cgroup_root *root = cgroup_root_from_kf(kf_root);
struct cgroup_sb_opts opts;
u16 added_mask, removed_mask;
- if (root == &cgrp_dfl_root) {
- pr_err("remount is not allowed\n");
- return -EINVAL;
- }
-
cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
/* See what subsystems are wanted */
@@ -1800,6 +1795,12 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)
return ret;
}
+static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)
+{
+ pr_err("remount is not allowed\n");
+ return -EINVAL;
+}
+
/*
* To reduce the fork() overhead for systems that are not actually using
* their cgroups capability, we don't maintain the lists running through
@@ -1902,6 +1903,7 @@ static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
{
LIST_HEAD(tmp_links);
struct cgroup *root_cgrp = &root->cgrp;
+ struct kernfs_syscall_ops *kf_sops;
struct css_set *cset;
int i, ret;
@@ -1933,7 +1935,10 @@ static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
if (ret)
goto cancel_ref;
- root->kf_root = kernfs_create_root(&cgroup_kf_syscall_ops,
+ kf_sops = root == &cgrp_dfl_root ?
+ &cgroup_kf_syscall_ops : &cgroup1_kf_syscall_ops;
+
+ root->kf_root = kernfs_create_root(kf_sops,
KERNFS_ROOT_CREATE_DEACTIVATED,
root_cgrp);
if (IS_ERR(root->kf_root)) {
@@ -4815,12 +4820,19 @@ static int cgroup_rmdir(struct kernfs_node *kn)
return ret;
}
+static struct kernfs_syscall_ops cgroup1_kf_syscall_ops = {
+ .remount_fs = cgroup1_remount,
+ .show_options = cgroup1_show_options,
+ .rename = cgroup1_rename,
+ .mkdir = cgroup_mkdir,
+ .rmdir = cgroup_rmdir,
+ .show_path = cgroup_show_path,
+};
+
static struct kernfs_syscall_ops cgroup_kf_syscall_ops = {
.remount_fs = cgroup_remount,
- .show_options = cgroup_show_options,
.mkdir = cgroup_mkdir,
.rmdir = cgroup_rmdir,
- .rename = cgroup_rename,
.show_path = cgroup_show_path,
};
--
2.9.3
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