move cgroupfs_root to include/linux/cgroup.h

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@kernel.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Li Zefan <lizefan@huawei.com>

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 45aee0fc6b98af8665a1a24c4b87337965ef4226..b21881e1ea088a4e2393aa84799d5e2c6abe50ad 100644 (file)
--- 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 67428d84e38bad75fbfa26b0094672bfb0bb7504..8b8eb7c168ff5de3c0287cbbfeb87e0e2bbc8a45 100644 (file)
--- 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 =