bcache: Kill dead cgroup code

This hasn't been used or even enabled in ages.

Signed-off-by: Kent Overstreet <[e-mail]>

drivers/md/bcache/Kconfig

···
 	Keeps all active closures in a linked list and provides a debugfs
 	interface to list them, which makes it possible to see asynchronous
 	operations that get stuck.
-
-# cgroup code needs to be updated:
-#
-#config CGROUP_BCACHE
-#	bool "Cgroup controls for bcache"
-#	depends on BCACHE && BLK_CGROUP
-#	---help---
-#	TODO

drivers/md/bcache/btree.c

···
  * alloc_bucket() cannot fail. This should be true but is not completely
  * obvious.
  *
- * Make sure all allocations get charged to the root cgroup
- *
  * Plugging?
  *
  * If data write is less than hard sector size of ssd, round up offset in open
  * bucket to the next whole sector
- *
- * Also lookup by cgroup in get_open_bucket()
  *
  * Superblock needs to be fleshed out for multiple cache devices
  *

drivers/md/bcache/request.c

···
 #include "request.h"
 #include "writeback.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>
 
···
 
 static void bch_data_insert_start(struct closure *);
 
-/* 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, loff_t *ppos)
-{
-	char tmp[1024];
-	int len = bch_snprint_string_list(tmp, PAGE_SIZE, bch_cache_modes,
-					  cgroup_to_bcache(cgrp)->cache_mode + 1);
-
-	if (len < 0)
-		return len;
-
-	return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
-}
-
-static int cache_mode_write(struct cgroup *cgrp, struct cftype *cft,
-			    const char *buf)
-{
-	int v = bch_read_string_list(buf, bch_cache_modes);
-	if (v < 0)
-		return v;
-
-	cgroup_to_bcache(cgrp)->cache_mode = v - 1;
-	return 0;
-}
-
-static u64 bch_verify_read(struct cgroup *cgrp, struct cftype *cft)
-{
-	return cgroup_to_bcache(cgrp)->verify;
-}
-
-static int bch_verify_write(struct cgroup *cgrp, struct cftype *cft, u64 val)
-{
-	cgroup_to_bcache(cgrp)->verify = val;
-	return 0;
-}
-
-static u64 bch_cache_hits_read(struct cgroup *cgrp, struct cftype *cft)
-{
-	struct bch_cgroup *bcachecg = cgroup_to_bcache(cgrp);
-	return atomic_read(&bcachecg->stats.cache_hits);
-}
-
-static u64 bch_cache_misses_read(struct cgroup *cgrp, struct cftype *cft)
-{
-	struct bch_cgroup *bcachecg = cgroup_to_bcache(cgrp);
-	return atomic_read(&bcachecg->stats.cache_misses);
-}
-
-static u64 bch_cache_bypass_hits_read(struct cgroup *cgrp,
-					 struct cftype *cft)
-{
-	struct bch_cgroup *bcachecg = cgroup_to_bcache(cgrp);
-	return atomic_read(&bcachecg->stats.cache_bypass_hits);
-}
-
-static u64 bch_cache_bypass_misses_read(struct cgroup *cgrp,
-					   struct cftype *cft)
-{
-	struct bch_cgroup *bcachecg = cgroup_to_bcache(cgrp);
-	return atomic_read(&bcachecg->stats.cache_bypass_misses);
-}
-
-static struct cftype bch_files[] = {
-	{
-		.name		= "cache_mode",
-		.read		= cache_mode_read,
-		.write_string	= cache_mode_write,
-	},
-	{
-		.name		= "verify",
-		.read_u64	= bch_verify_read,
-		.write_u64	= bch_verify_write,
-	},
-	{
-		.name		= "cache_hits",
-		.read_u64	= bch_cache_hits_read,
-	},
-	{
-		.name		= "cache_misses",
-		.read_u64	= bch_cache_misses_read,
-	},
-	{
-		.name		= "cache_bypass_hits",
-		.read_u64	= bch_cache_bypass_hits_read,
-	},
-	{
-		.name		= "cache_bypass_misses",
-		.read_u64	= bch_cache_bypass_misses_read,
-	},
-	{ }	/* terminate */
-};
-
-static void init_bch_cgroup(struct bch_cgroup *cg)
-{
-	cg->cache_mode = -1;
-}
-
-static struct cgroup_subsys_state *bcachecg_create(struct cgroup *cgroup)
-{
-	struct bch_cgroup *cg;
-
-	cg = kzalloc(sizeof(*cg), GFP_KERNEL);
-	if (!cg)
-		return ERR_PTR(-ENOMEM);
-	init_bch_cgroup(cg);
-	return &cg->css;
-}
-
-static void bcachecg_destroy(struct cgroup *cgroup)
-{
-	struct bch_cgroup *cg = cgroup_to_bcache(cgroup);
-	kfree(cg);
-}
-
-struct cgroup_subsys bcache_subsys = {
-	.create		= bcachecg_create,
-	.destroy	= bcachecg_destroy,
-	.subsys_id	= bcache_subsys_id,
-	.name		= "bcache",
-	.module		= THIS_MODULE,
-};
-EXPORT_SYMBOL_GPL(bcache_subsys);
-#endif
-
 static unsigned cache_mode(struct cached_dev *dc, struct bio *bio)
 {
-#ifdef CONFIG_CGROUP_BCACHE
-	int r = bch_bio_to_cgroup(bio)->cache_mode;
-	if (r >= 0)
-		return r;
-#endif
 	return BDEV_CACHE_MODE(&dc->sb);
 }
 
 static bool verify(struct cached_dev *dc, struct bio *bio)
 {
-#ifdef CONFIG_CGROUP_BCACHE
-	if (bch_bio_to_cgroup(bio)->verify)
-		return true;
-#endif
 	return dc->verify;
 }
 
···
 
 void bch_request_exit(void)
 {
-#ifdef CONFIG_CGROUP_BCACHE
-	cgroup_unload_subsys(&bcache_subsys);
-#endif
 	if (bch_search_cache)
 		kmem_cache_destroy(bch_search_cache);
 }
···
 	if (!bch_search_cache)
 		return -ENOMEM;
 
-#ifdef CONFIG_CGROUP_BCACHE
-	cgroup_load_subsys(&bcache_subsys);
-	init_bch_cgroup(&bcache_default_cgroup);
-
-	cgroup_add_cftypes(&bcache_subsys, bch_files);
-#endif
 	return 0;
 }

drivers/md/bcache/request.h

···
 #ifndef _BCACHE_REQUEST_H_
 #define _BCACHE_REQUEST_H_
 
-#include <linux/cgroup.h>
-
 struct data_insert_op {
 	struct closure		cl;
 	struct cache_set	*c;
···
 void bch_flash_dev_request_init(struct bcache_device *d);
 
 extern struct kmem_cache *bch_search_cache, *bch_passthrough_cache;
-
-struct bch_cgroup {
-#ifdef CONFIG_CGROUP_BCACHE
-	struct cgroup_subsys_state	css;
-#endif
-	/*
-	 * We subtract one from the index into bch_cache_modes[], so that
-	 * default == -1; this makes it so the rest match up with d->cache_mode,
-	 * and we use d->cache_mode if cgrp->cache_mode < 0
-	 */
-	short				cache_mode;
-	bool				verify;
-	struct cache_stat_collector	stats;
-};
-
-struct bch_cgroup *bch_bio_to_cgroup(struct bio *bio);
 
 #endif /* _BCACHE_REQUEST_H_ */

drivers/md/bcache/stats.c

···
 	struct cached_dev *dc = container_of(d, struct cached_dev, disk);
 	mark_cache_stats(&dc->accounting.collector, hit, bypass);
 	mark_cache_stats(&c->accounting.collector, hit, bypass);
-#ifdef CONFIG_CGROUP_BCACHE
-	mark_cache_stats(&(bch_bio_to_cgroup(s->orig_bio)->stats), hit, bypass);
-#endif
 }
 
 void bch_mark_cache_readahead(struct cache_set *c, struct bcache_device *d)