1 files changed, 55 insertions, 26 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 5a85b3415c1b..d3f5fba2c159 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -16,6 +16,7 @@
 #include <linux/prio_heap.h>
 #include <linux/rwsem.h>
 #include <linux/idr.h>
+#include <linux/workqueue.h>
 
 #ifdef CONFIG_CGROUPS
 
@@ -76,12 +77,16 @@ struct cgroup_subsys_state {
         unsigned long flags;
         /* ID for this css, if possible */
         struct css_id __rcu *id;
+
+        /* Used to put @cgroup->dentry on the last css_put() */
+        struct work_struct dput_work;
 };
 
 /* bits in struct cgroup_subsys_state flags field */
 enum {
         CSS_ROOT, /* This CSS is the root of the subsystem */
         CSS_REMOVED, /* This CSS is dead */
+        CSS_CLEAR_CSS_REFS,             /* @ss->__DEPRECATED_clear_css_refs */
 };
 
 /* Caller must verify that the css is not for root cgroup */
@@ -115,16 +120,12 @@ static inline bool css_is_removed(struct cgroup_subsys_state *css)
  * the css has been destroyed.
  */
 
+extern bool __css_tryget(struct cgroup_subsys_state *css);
 static inline bool css_tryget(struct cgroup_subsys_state *css)
 {
         if (test_bit(CSS_ROOT, &css->flags))
                 return true;
-        while (!atomic_inc_not_zero(&css->refcnt)) {
-                if (test_bit(CSS_REMOVED, &css->flags))
-                        return false;
-                cpu_relax();
-        }
-        return true;
+        return __css_tryget(css);
 }
 
 /*
@@ -132,11 +133,11 @@ static inline bool css_tryget(struct cgroup_subsys_state *css)
  * css_get() or css_tryget()
  */
 
-extern void __css_put(struct cgroup_subsys_state *css, int count);
+extern void __css_put(struct cgroup_subsys_state *css);
 static inline void css_put(struct cgroup_subsys_state *css)
 {
         if (!test_bit(CSS_ROOT, &css->flags))
-                __css_put(css, 1);
+                __css_put(css);
 }
 
 /* bits in struct cgroup flags field */
@@ -175,6 +176,7 @@ struct cgroup {
          */
         struct list_head sibling;       /* my parent's children */
         struct list_head children;      /* my children */
+        struct list_head files;         /* my files */
 
         struct cgroup *parent;          /* my parent */
         struct dentry __rcu *dentry;    /* cgroup fs entry, RCU protected */
@@ -191,6 +193,9 @@ struct cgroup {
          */
         struct list_head css_sets;
 
+        struct list_head allcg_node;    /* cgroupfs_root->allcg_list */
+        struct list_head cft_q_node;    /* used during cftype add/rm */
+
         /*
          * Linked list running through all cgroups that can
          * potentially be reaped by the release agent. Protected by
@@ -275,11 +280,17 @@ struct cgroup_map_cb {
  *      - the 'cftype' of the file is file->f_dentry->d_fsdata
  */
 
-#define MAX_CFTYPE_NAME 64
+/* cftype->flags */
+#define CFTYPE_ONLY_ON_ROOT     (1U << 0)       /* only create on root cg */
+#define CFTYPE_NOT_ON_ROOT      (1U << 1)       /* don't create onp root cg */
+
+#define MAX_CFTYPE_NAME         64
+
 struct cftype {
         /*
          * By convention, the name should begin with the name of the
-         * subsystem, followed by a period
+         * subsystem, followed by a period.  Zero length string indicates
+         * end of cftype array.
          */
         char name[MAX_CFTYPE_NAME];
         int private;
@@ -295,6 +306,9 @@ struct cftype {
          */
         size_t max_write_len;
 
+        /* CFTYPE_* flags */
+        unsigned int flags;
+
         int (*open)(struct inode *inode, struct file *file);
         ssize_t (*read)(struct cgroup *cgrp, struct cftype *cft,
                         struct file *file,
@@ -373,6 +387,16 @@ struct cftype {
                         struct eventfd_ctx *eventfd);
 };
 
+/*
+ * cftype_sets describe cftypes belonging to a subsystem and are chained at
+ * cgroup_subsys->cftsets.  Each cftset points to an array of cftypes
+ * terminated by zero length name.
+ */
+struct cftype_set {
+        struct list_head                node;   /* chained at subsys->cftsets */
+        const struct cftype             *cfts;
+};
+
 struct cgroup_scanner {
         struct cgroup *cg;
         int (*test_task)(struct task_struct *p, struct cgroup_scanner *scan);
@@ -382,21 +406,8 @@ struct cgroup_scanner {
         void *data;
 };
 
-/*
- * Add a new file to the given cgroup directory. Should only be
- * called by subsystems from within a populate() method
- */
-int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys,
-                       const struct cftype *cft);
-
-/*
- * Add a set of new files to the given cgroup directory. Should
- * only be called by subsystems from within a populate() method
- */
-int cgroup_add_files(struct cgroup *cgrp,
-                        struct cgroup_subsys *subsys,
-                        const struct cftype cft[],
-                        int count);
+int cgroup_add_cftypes(struct cgroup_subsys *ss, const struct cftype *cfts);
+int cgroup_rm_cftypes(struct cgroup_subsys *ss, const struct cftype *cfts);
 
 int cgroup_is_removed(const struct cgroup *cgrp);
 
@@ -461,7 +472,6 @@ struct cgroup_subsys {
         void (*fork)(struct task_struct *task);
         void (*exit)(struct cgroup *cgrp, struct cgroup *old_cgrp,
                      struct task_struct *task);
-        int (*populate)(struct cgroup_subsys *ss, struct cgroup *cgrp);
         void (*post_clone)(struct cgroup *cgrp);
         void (*bind)(struct cgroup *root);
 
@@ -474,6 +484,18 @@ struct cgroup_subsys {
          * (not available in early_init time.)
          */
         bool use_id;
+
+        /*
+         * If %true, cgroup removal will try to clear css refs by retrying
+         * ss->pre_destroy() until there's no css ref left.  This behavior
+         * is strictly for backward compatibility and will be removed as
+         * soon as the current user (memcg) is updated.
+         *
+         * If %false, ss->pre_destroy() can't fail and cgroup removal won't
+         * wait for css refs to drop to zero before proceeding.
+         */
+        bool __DEPRECATED_clear_css_refs;
+
 #define MAX_CGROUP_TYPE_NAMELEN 32
         const char *name;
 
@@ -500,6 +522,13 @@ struct cgroup_subsys {
         struct idr idr;
         spinlock_t id_lock;
 
+        /* list of cftype_sets */
+        struct list_head cftsets;
+
+        /* base cftypes, automatically [de]registered with subsys itself */
+        struct cftype *base_cftypes;
+        struct cftype_set base_cftset;
+
         /* should be defined only by modular subsystems */
         struct module *module;
 };