[PATCH 2/4] move cgroupfs_root to include/linux/cgroup.h

From: Tejun Heo
Date: Fri Apr 12 2013 - 19:11:36 EST


While controllers shouldn't be accessing cgroupfs_root directly, it
being hidden inside kern/cgroup.c makes somethings pretty silly. This
makes routing hierarchy-wide settings which need to be visible to
controllers cumbersome.

We're gonna add another hierarchy-wide setting which needs to be
accessed from controllers. Move cgroupfs_root and its flags to the
header file so that we can access root settings with inline helpers.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
include/linux/cgroup.h | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++
kernel/cgroup.c | 57 --------------------------------------------------
2 files changed, 57 insertions(+), 57 deletions(-)

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 45aee0f..b21881e 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -19,6 +19,7 @@
#include <linux/idr.h>
#include <linux/workqueue.h>
#include <linux/xattr.h>
+#include <linux/fs.h>

#ifdef CONFIG_CGROUPS

@@ -238,6 +239,62 @@ struct cgroup {
struct simple_xattrs xattrs;
};

+#define MAX_CGROUP_ROOT_NAMELEN 64
+
+/* cgroupfs_root->flags */
+enum {
+ CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */
+ CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */
+};
+
+/*
+ * A cgroupfs_root represents the root of a cgroup hierarchy, and may be
+ * associated with a superblock to form an active hierarchy. This is
+ * internal to cgroup core. Don't access directly from controllers.
+ */
+struct cgroupfs_root {
+ struct super_block *sb;
+
+ /*
+ * The bitmask of subsystems intended to be attached to this
+ * hierarchy
+ */
+ unsigned long subsys_mask;
+
+ /* Unique id for this hierarchy. */
+ int hierarchy_id;
+
+ /* The bitmask of subsystems currently attached to this hierarchy */
+ unsigned long actual_subsys_mask;
+
+ /* A list running through the attached subsystems */
+ struct list_head subsys_list;
+
+ /* The root cgroup for this hierarchy */
+ struct cgroup top_cgroup;
+
+ /* Tracks how many cgroups are currently defined in hierarchy.*/
+ int number_of_cgroups;
+
+ /* A list running through the active hierarchies */
+ struct list_head root_list;
+
+ /* All cgroups on this root, cgroup_mutex protected */
+ struct list_head allcg_list;
+
+ /* Hierarchy-specific flags */
+ unsigned long flags;
+
+ /* IDs for cgroups in this hierarchy */
+ struct ida cgroup_ida;
+
+ /* The path to use for release notifications. */
+ char release_agent_path[PATH_MAX];
+
+ /* The name for this hierarchy - may be empty */
+ char name[MAX_CGROUP_ROOT_NAMELEN];
+};
+
/*
* A css_set is a structure holding pointers to a set of
* cgroup_subsys_state objects. This saves space in the task struct
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index a372eaa..8848070 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -30,7 +30,6 @@
#include <linux/cred.h>
#include <linux/ctype.h>
#include <linux/errno.h>
-#include <linux/fs.h>
#include <linux/init_task.h>
#include <linux/kernel.h>
#include <linux/list.h>
@@ -104,56 +103,6 @@ static struct cgroup_subsys *subsys[CGROUP_SUBSYS_COUNT] = {
#include <linux/cgroup_subsys.h>
};

-#define MAX_CGROUP_ROOT_NAMELEN 64
-
-/*
- * A cgroupfs_root represents the root of a cgroup hierarchy,
- * and may be associated with a superblock to form an active
- * hierarchy
- */
-struct cgroupfs_root {
- struct super_block *sb;
-
- /*
- * The bitmask of subsystems intended to be attached to this
- * hierarchy
- */
- unsigned long subsys_mask;
-
- /* Unique id for this hierarchy. */
- int hierarchy_id;
-
- /* The bitmask of subsystems currently attached to this hierarchy */
- unsigned long actual_subsys_mask;
-
- /* A list running through the attached subsystems */
- struct list_head subsys_list;
-
- /* The root cgroup for this hierarchy */
- struct cgroup top_cgroup;
-
- /* Tracks how many cgroups are currently defined in hierarchy.*/
- int number_of_cgroups;
-
- /* A list running through the active hierarchies */
- struct list_head root_list;
-
- /* All cgroups on this root, cgroup_mutex protected */
- struct list_head allcg_list;
-
- /* Hierarchy-specific flags */
- unsigned long flags;
-
- /* IDs for cgroups in this hierarchy */
- struct ida cgroup_ida;
-
- /* The path to use for release notifications. */
- char release_agent_path[PATH_MAX];
-
- /* The name for this hierarchy - may be empty */
- char name[MAX_CGROUP_ROOT_NAMELEN];
-};
-
/*
* The "rootnode" hierarchy is the "dummy hierarchy", reserved for the
* subsystems that are otherwise unattached - it never has more than a
@@ -296,12 +245,6 @@ bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor)
}
EXPORT_SYMBOL_GPL(cgroup_is_descendant);

-/* cgroupfs_root->flags */
-enum {
- CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */
- CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */
-};
-
static int cgroup_is_releasable(const struct cgroup *cgrp)
{
const int bits =
--
1.8.1.4

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