linux-imx

/*

 * Common Block IO controller cgroup interface

 *

 * Based on ideas and code from CFQ, CFS and BFQ:

 * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>

 *

 * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>

 *            Paolo Valente <paolo.valente@unimore.it>

 *

 * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>

 *                Nauman Rafique <nauman@google.com>

 *

 * For policy-specific per-blkcg data:

 * Copyright (C) 2015 Paolo Valente <paolo.valente@unimore.it>

 *                    Arianna Avanzini <avanzini.arianna@gmail.com>

 */

#include <linux/ioprio.h>

#include <linux/kdev_t.h>

#include <linux/module.h>

#include <linux/sched/signal.h>

#include <linux/err.h>

#include <linux/blkdev.h>

#include <linux/backing-dev.h>

#include <linux/slab.h>

#include <linux/genhd.h>

#include <linux/delay.h>

#include <linux/atomic.h>

#include <linux/ctype.h>

#include <linux/blk-cgroup.h>

#include <linux/tracehook.h>

#include "blk.h"

​

#define MAX_KEY_LEN 100

​

/*

 * blkcg_pol_mutex protects blkcg_policy[] and policy [de]activation.

 * blkcg_pol_register_mutex nests outside of it and synchronizes entire

 * policy [un]register operations including cgroup file additions /

 * removals.  Putting cgroup file registration outside blkcg_pol_mutex

 * allows grabbing it from cgroup callbacks.

 */

static DEFINE_MUTEX(blkcg_pol_register_mutex);

static DEFINE_MUTEX(blkcg_pol_mutex);

​

struct blkcg blkcg_root;

EXPORT_SYMBOL_GPL(blkcg_root);

​

struct cgroup_subsys_state * const blkcg_root_css = &blkcg_root.css;

​

static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];

​

static LIST_HEAD(all_blkcgs);       /* protected by blkcg_pol_mutex */

​

static bool blkcg_debug_stats = false;

​

static bool blkcg_policy_enabled(struct request_queue *q,

                 const struct blkcg_policy *pol)

{

    return pol && test_bit(pol->plid, q->blkcg_pols);

}

​

/**

 * blkg_free - free a blkg