/*
* Main bcache entry point - handle a read or a write request and decide what to
* do with it; the make_request functions are called by the block layer.
*
* Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "request.h"
#include <linux/cgroup.h>
#include <linux/module.h>
#include <linux/hash.h>
#include <linux/random.h>
#include "blk-cgroup.h"
#include <trace/events/bcache.h>
#define CUTOFF_CACHE_ADD 95
#define CUTOFF_CACHE_READA 90
#define CUTOFF_WRITEBACK 50
#define CUTOFF_WRITEBACK_SYNC 75
struct kmem_cache *bch_search_cache;
static void check_should_skip(struct cached_dev *, struct search *);
/* Cgroup interface */
#ifdef CONFIG_CGROUP_BCACHE
static struct bch_cgroup bcache_default_cgroup = { .cache_mode = -1 };
static struct bch_cgroup *cgroup_to_bcache(struct cgroup *cgroup)
{
struct cgroup_subsys_state *css;
return cgroup &&
(css = cgroup_subsys_state(cgroup, bcache_subsys_id))
? container_of(css, struct bch_cgroup, css)
: &bcache_default_cgroup;
}
struct bch_cgroup *bch_bio_to_cgroup(struct bio *bio)
{
struct cgroup_subsys_state *css = bio->bi_css
? cgroup_subsys_state(bio->bi_css->cgroup, bcache_subsys_id)
: task_subsys_state(current, bcache_subsys_id);
return css
? container_of(css, struct bch_cgroup, css)
: &bcache_default_cgroup;
}
static ssize_t cache_mode_read(struct cgroup *cgrp, struct cftype *cft,
struct file *file,
char __user *buf, size_t nbytes, 