Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:

 - cgroup v2 interface is now official.  It's no longer hidden behind a
   devel flag and can be mounted using the new cgroup2 fs type.

   Unfortunately, cpu v2 interface hasn't made it yet due to the
   discussion around in-process hierarchical resource distribution and
   only memory and io controllers can be used on the v2 interface at the
   moment.

 - The existing documentation which has always been a bit of mess is
   relocated under Documentation/cgroup-v1/. Documentation/cgroup-v2.txt
   is added as the authoritative documentation for the v2 interface.

 - Some features are added through for-4.5-ancestor-test branch to
   enable netfilter xt_cgroup match to use cgroup v2 paths.  The actual
   netfilter changes will be merged through the net tree which pulled in
   the said branch.

 - Various cleanups

* 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: rename cgroup documentations
  cgroup: fix a typo.
  cgroup: Remove resource_counter.txt in Documentation/cgroup-legacy/00-INDEX.
  cgroup: demote subsystem init messages to KERN_DEBUG
  cgroup: Fix uninitialized variable warning
  cgroup: put controller Kconfig options in meaningful order
  cgroup: clean up the kernel configuration menu nomenclature
  cgroup_pids: fix a typo.
  Subject: cgroup: Fix incomplete dd command in blkio documentation
  cgroup: kill cgrp_ss_priv[CGROUP_CANFORK_COUNT] and friends
  cpuset: Replace all instances of time_t with time64_t
  cgroup: replace unified-hierarchy.txt with a proper cgroup v2 documentation
  cgroup: rename Documentation/cgroups/ to Documentation/cgroup-legacy/
  cgroup: replace __DEVEL__sane_behavior with cgroup2 fs type

4 files changed, 10 insertions, 41 deletions

diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index e5f4164cbd99..7f540f7f588d 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -34,17 +34,12 @@ struct seq_file;
 
 /* define the enumeration of all cgroup subsystems */
 #define SUBSYS(_x) _x ## _cgrp_id,
-#define SUBSYS_TAG(_t) CGROUP_ ## _t, \
-	__unused_tag_ ## _t = CGROUP_ ## _t - 1,
 enum cgroup_subsys_id {
 #include <linux/cgroup_subsys.h>
 	CGROUP_SUBSYS_COUNT,
 };
-#undef SUBSYS_TAG
 #undef SUBSYS
 
-#define CGROUP_CANFORK_COUNT (CGROUP_CANFORK_END - CGROUP_CANFORK_START)
-
 /* bits in struct cgroup_subsys_state flags field */
 enum {
 	CSS_NO_REF	= (1 << 0), /* no reference counting for this css */
@@ -66,7 +61,6 @@ enum {
 
 /* cgroup_root->flags */
 enum {
-	CGRP_ROOT_SANE_BEHAVIOR	= (1 << 0), /* __DEVEL__sane_behavior specified */
 	CGRP_ROOT_NOPREFIX	= (1 << 1), /* mounted subsystems have no named prefix */
 	CGRP_ROOT_XATTR		= (1 << 2), /* supports extended attributes */
 };
@@ -439,9 +433,9 @@ struct cgroup_subsys {
 	int (*can_attach)(struct cgroup_taskset *tset);
 	void (*cancel_attach)(struct cgroup_taskset *tset);
 	void (*attach)(struct cgroup_taskset *tset);
-	int (*can_fork)(struct task_struct *task, void **priv_p);
-	void (*cancel_fork)(struct task_struct *task, void *priv);
-	void (*fork)(struct task_struct *task, void *priv);
+	int (*can_fork)(struct task_struct *task);
+	void (*cancel_fork)(struct task_struct *task);
+	void (*fork)(struct task_struct *task);
 	void (*exit)(struct task_struct *task);
 	void (*free)(struct task_struct *task);
 	void (*bind)(struct cgroup_subsys_state *root_css);
@@ -527,7 +521,6 @@ static inline void cgroup_threadgroup_change_end(struct task_struct *tsk)
 
 #else	/* CONFIG_CGROUPS */
 
-#define CGROUP_CANFORK_COUNT 0
 #define CGROUP_SUBSYS_COUNT 0
 
 static inline void cgroup_threadgroup_change_begin(struct task_struct *tsk) {}
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 322a28482745..2162dca88dc0 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -97,12 +97,9 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
 		     struct pid *pid, struct task_struct *tsk);
 
 void cgroup_fork(struct task_struct *p);
-extern int cgroup_can_fork(struct task_struct *p,
-			   void *ss_priv[CGROUP_CANFORK_COUNT]);
-extern void cgroup_cancel_fork(struct task_struct *p,
-			       void *ss_priv[CGROUP_CANFORK_COUNT]);
-extern void cgroup_post_fork(struct task_struct *p,
-			     void *old_ss_priv[CGROUP_CANFORK_COUNT]);
+extern int cgroup_can_fork(struct task_struct *p);
+extern void cgroup_cancel_fork(struct task_struct *p);
+extern void cgroup_post_fork(struct task_struct *p);
 void cgroup_exit(struct task_struct *p);
 void cgroup_free(struct task_struct *p);
 
@@ -562,13 +559,9 @@ static inline int cgroupstats_build(struct cgroupstats *stats,
 				    struct dentry *dentry) { return -EINVAL; }
 
 static inline void cgroup_fork(struct task_struct *p) {}
-static inline int cgroup_can_fork(struct task_struct *p,
-				  void *ss_priv[CGROUP_CANFORK_COUNT])
-{ return 0; }
-static inline void cgroup_cancel_fork(struct task_struct *p,
-				      void *ss_priv[CGROUP_CANFORK_COUNT]) {}
-static inline void cgroup_post_fork(struct task_struct *p,
-				    void *ss_priv[CGROUP_CANFORK_COUNT]) {}
+static inline int cgroup_can_fork(struct task_struct *p) { return 0; }
+static inline void cgroup_cancel_fork(struct task_struct *p) {}
+static inline void cgroup_post_fork(struct task_struct *p) {}
 static inline void cgroup_exit(struct task_struct *p) {}
 static inline void cgroup_free(struct task_struct *p) {}
 
diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index 1a96fdaa33d5..0df0336acee9 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -6,14 +6,8 @@
 
 /*
  * This file *must* be included with SUBSYS() defined.
- * SUBSYS_TAG() is a noop if undefined.
  */
 
-#ifndef SUBSYS_TAG
-#define __TMP_SUBSYS_TAG
-#define SUBSYS_TAG(_x)
-#endif
-
 #if IS_ENABLED(CONFIG_CPUSETS)
 SUBSYS(cpuset)
 #endif
@@ -58,17 +52,10 @@ SUBSYS(net_prio)
 SUBSYS(hugetlb)
 #endif
 
-/*
- * Subsystems that implement the can_fork() family of callbacks.
- */
-SUBSYS_TAG(CANFORK_START)
-
 #if IS_ENABLED(CONFIG_CGROUP_PIDS)
 SUBSYS(pids)
 #endif
 
-SUBSYS_TAG(CANFORK_END)
-
 /*
  * The following subsystems are not supported on the default hierarchy.
  */
@@ -76,11 +63,6 @@ SUBSYS_TAG(CANFORK_END)
 SUBSYS(debug)
 #endif
 
-#ifdef __TMP_SUBSYS_TAG
-#undef __TMP_SUBSYS_TAG
-#undef SUBSYS_TAG
-#endif
-
 /*
  * DO NOT ADD ANY SUBSYSTEM WITHOUT EXPLICIT ACKS FROM CGROUP MAINTAINERS.
  */
diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h
index accb036bbc9c..b283d56c1db9 100644
--- a/include/uapi/linux/magic.h
+++ b/include/uapi/linux/magic.h
@@ -54,6 +54,7 @@
 
 #define SMB_SUPER_MAGIC		0x517B
 #define CGROUP_SUPER_MAGIC	0x27e0eb
+#define CGROUP2_SUPER_MAGIC	0x63677270
 
 
 #define STACK_END_MAGIC		0x57AC6E9D