Commit 346dbf1b authored by Mikulas Patocka's avatar Mikulas Patocka
Browse files

dm-cache: fix warnings about duplicate slab caches 



The commit 4c395296 adds a warning about duplicate cache names if
CONFIG_DEBUG_VM is selected. These warnings are triggered by the dm-cache
code.

The dm-cache code allocates a slab cache for each device. This commit
changes it to allocate just one slab cache in the module init function.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Fixes: 4c395296 ("slab: Warn on duplicate cache names when DEBUG_VM=y")
parent 42964e4b

drivers/md/dm-cache-background-tracker.c

+6 −19
Original line number Diff line number Diff line
@@ -11,12 +11,6 @@ 


#define DM_MSG_PREFIX "dm-background-tracker"



struct bt_work {

	struct list_head list;

	struct rb_node node;

	struct policy_work work;

};



struct background_tracker {

	unsigned int max_work;

	atomic_t pending_promotes;
@@ -26,10 +20,10 @@ struct background_tracker { 
	struct list_head issued;

	struct list_head queued;

	struct rb_root pending;



	struct kmem_cache *work_cache;

};



struct kmem_cache *btracker_work_cache = NULL;



struct background_tracker *btracker_create(unsigned int max_work)

{

	struct background_tracker *b = kmalloc(sizeof(*b), GFP_KERNEL);
@@ -48,12 +42,6 @@ struct background_tracker *btracker_create(unsigned int max_work) 
	INIT_LIST_HEAD(&b->queued);



	b->pending = RB_ROOT;

	b->work_cache = KMEM_CACHE(bt_work, 0);

	if (!b->work_cache) {

		DMERR("couldn't create mempool for background work items");

		kfree(b);

		b = NULL;

	}



	return b;

}
@@ -66,10 +54,9 @@ void btracker_destroy(struct background_tracker *b) 
	BUG_ON(!list_empty(&b->issued));

	list_for_each_entry_safe (w, tmp, &b->queued, list) {

		list_del(&w->list);

		kmem_cache_free(b->work_cache, w);

		kmem_cache_free(btracker_work_cache, w);

	}



	kmem_cache_destroy(b->work_cache);

	kfree(b);

}

EXPORT_SYMBOL_GPL(btracker_destroy);
@@ -180,7 +167,7 @@ static struct bt_work *alloc_work(struct background_tracker *b) 
	if (max_work_reached(b))

		return NULL;



	return kmem_cache_alloc(b->work_cache, GFP_NOWAIT);

	return kmem_cache_alloc(btracker_work_cache, GFP_NOWAIT);

}



int btracker_queue(struct background_tracker *b,
@@ -203,7 +190,7 @@ int btracker_queue(struct background_tracker *b, 
		 * There was a race, we'll just ignore this second

		 * bit of work for the same oblock.

		 */

		kmem_cache_free(b->work_cache, w);

		kmem_cache_free(btracker_work_cache, w);

		return -EINVAL;

	}
@@ -244,7 +231,7 @@ void btracker_complete(struct background_tracker *b, 
	update_stats(b, &w->work, -1);

	rb_erase(&w->node, &b->pending);

	list_del(&w->list);

	kmem_cache_free(b->work_cache, w);

	kmem_cache_free(btracker_work_cache, w);

}

EXPORT_SYMBOL_GPL(btracker_complete);

drivers/md/dm-cache-background-tracker.h

+8 −0
Original line number Diff line number Diff line
@@ -26,6 +26,14 @@ 
 * protected with a spinlock.

 */



struct bt_work {

	struct list_head list;

	struct rb_node node;

	struct policy_work work;

};



extern struct kmem_cache *btracker_work_cache;



struct background_work;

struct background_tracker;

drivers/md/dm-cache-target.c

+20 −5
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include "dm-bio-record.h"

#include "dm-cache-metadata.h"

#include "dm-io-tracker.h"

#include "dm-cache-background-tracker.h"



#include <linux/dm-io.h>

#include <linux/dm-kcopyd.h>
@@ -2263,7 +2264,7 @@ static int parse_cache_args(struct cache_args *ca, int argc, char **argv, 


/*----------------------------------------------------------------*/



static struct kmem_cache *migration_cache;

static struct kmem_cache *migration_cache = NULL;



#define NOT_CORE_OPTION 1
@@ -3445,22 +3446,36 @@ static int __init dm_cache_init(void) 
	int r;



	migration_cache = KMEM_CACHE(dm_cache_migration, 0);

	if (!migration_cache)

		return -ENOMEM;

	if (!migration_cache) {

		r = -ENOMEM;

		goto err;

	}



	btracker_work_cache = kmem_cache_create("dm_cache_bt_work",

		sizeof(struct bt_work), __alignof__(struct bt_work), 0, NULL);

	if (!btracker_work_cache) {

		r = -ENOMEM;

		goto err;

	}



	r = dm_register_target(&cache_target);

	if (r) {

		kmem_cache_destroy(migration_cache);

		return r;

		goto err;

	}



	return 0;



err:

	kmem_cache_destroy(migration_cache);

	kmem_cache_destroy(btracker_work_cache);

	return r;

}



static void __exit dm_cache_exit(void)

{

	dm_unregister_target(&cache_target);

	kmem_cache_destroy(migration_cache);

	kmem_cache_destroy(btracker_work_cache);

}



module_init(dm_cache_init);