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Commit b53202e6 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Tejun Heo
Browse files

cgroup: kill cgrp_ss_priv[CGROUP_CANFORK_COUNT] and friends 



Now that nobody use the "priv" arg passed to can_fork/cancel_fork/fork we can
kill CGROUP_CANFORK_COUNT/SUBSYS_TAG/etc and cgrp_ss_priv[] in copy_process().

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 8075b542

include/linux/cgroup-defs.h

+3 −9
Original line number Diff line number Diff line
@@ -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 */
@@ -424,9 +419,9 @@ 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);
@@ -512,7 +507,6 @@ 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) {}

include/linux/cgroup.h

+6 −13
Original line number Diff line number Diff line
@@ -96,12 +96,9 @@ 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);
@@ -539,13 +536,9 @@ 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) {}

include/linux/cgroup_subsys.h

+0 −18
Original line number Diff line number Diff line
@@ -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.

 */

kernel/cgroup.c

+7 −23
Original line number Diff line number Diff line
@@ -5488,19 +5488,6 @@ static const struct file_operations proc_cgroupstats_operations = { 
	.release = single_release,

};



static void **subsys_canfork_priv_p(void *ss_priv[CGROUP_CANFORK_COUNT], int i)

{

	if (CGROUP_CANFORK_START <= i && i < CGROUP_CANFORK_END)

		return &ss_priv[i - CGROUP_CANFORK_START];

	return NULL;

}



static void *subsys_canfork_priv(void *ss_priv[CGROUP_CANFORK_COUNT], int i)

{

	void **private = subsys_canfork_priv_p(ss_priv, i);

	return private ? *private : NULL;

}



/**

 * cgroup_fork - initialize cgroup related fields during copy_process()

 * @child: pointer to task_struct of forking parent process.
@@ -5523,14 +5510,13 @@ void cgroup_fork(struct task_struct *child) 
 * returns an error, the fork aborts with that error code. This allows for

 * a cgroup subsystem to conditionally allow or deny new forks.

 */

int cgroup_can_fork(struct task_struct *child,

		    void *ss_priv[CGROUP_CANFORK_COUNT])

int cgroup_can_fork(struct task_struct *child)

{

	struct cgroup_subsys *ss;

	int i, j, ret;



	for_each_subsys_which(ss, i, &have_canfork_callback) {

		ret = ss->can_fork(child, subsys_canfork_priv_p(ss_priv, i));

		ret = ss->can_fork(child);

		if (ret)

			goto out_revert;

	}
@@ -5542,7 +5528,7 @@ int cgroup_can_fork(struct task_struct *child, 
		if (j >= i)

			break;

		if (ss->cancel_fork)

			ss->cancel_fork(child, subsys_canfork_priv(ss_priv, j));

			ss->cancel_fork(child);

	}



	return ret;
@@ -5555,15 +5541,14 @@ int cgroup_can_fork(struct task_struct *child, 
 * This calls the cancel_fork() callbacks if a fork failed *after*

 * cgroup_can_fork() succeded.

 */

void cgroup_cancel_fork(struct task_struct *child,

			void *ss_priv[CGROUP_CANFORK_COUNT])

void cgroup_cancel_fork(struct task_struct *child)

{

	struct cgroup_subsys *ss;

	int i;



	for_each_subsys(ss, i)

		if (ss->cancel_fork)

			ss->cancel_fork(child, subsys_canfork_priv(ss_priv, i));

			ss->cancel_fork(child);

}



/**
@@ -5576,8 +5561,7 @@ void cgroup_cancel_fork(struct task_struct *child, 
 * cgroup_task_iter_start() - to guarantee that the new task ends up on its

 * list.

 */

void cgroup_post_fork(struct task_struct *child,

		      void *old_ss_priv[CGROUP_CANFORK_COUNT])

void cgroup_post_fork(struct task_struct *child)

{

	struct cgroup_subsys *ss;

	int i;
@@ -5621,7 +5605,7 @@ void cgroup_post_fork(struct task_struct *child, 
	 * and addition to css_set.

	 */

	for_each_subsys_which(ss, i, &have_fork_callback)

		ss->fork(child, subsys_canfork_priv(old_ss_priv, i));

		ss->fork(child);

}



/**

kernel/cgroup_freezer.c

+1 −1
Original line number Diff line number Diff line
@@ -200,7 +200,7 @@ static void freezer_attach(struct cgroup_taskset *tset) 
 * to do anything as freezer_attach() will put @task into the appropriate

 * state.

 */

static void freezer_fork(struct task_struct *task, void *private)

static void freezer_fork(struct task_struct *task)

{

	struct freezer *freezer;