- fix warnings about duplicate slab cache names

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Merge tag 'for-6.12/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mikulas Patocka:

 - fix warnings about duplicate slab cache names

* tag 'for-6.12/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm-cache: fix warnings about duplicate slab caches
  dm-bufio: fix warnings about duplicate slab caches

drivers/md/dm-bufio.c

@@ -2471,7 +2471,8 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
 	int r;
 	unsigned int num_locks;
 	struct dm_bufio_client *c;
-	char slab_name[27];
+	char slab_name[64];
+	static atomic_t seqno = ATOMIC_INIT(0);
 
 	if (!block_size || block_size & ((1 << SECTOR_SHIFT) - 1)) {
 		DMERR("%s: block size not specified or is not multiple of 512b", __func__);
@@ -2522,7 +2523,8 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
 	    (block_size < PAGE_SIZE || !is_power_of_2(block_size))) {
 		unsigned int align = min(1U << __ffs(block_size), (unsigned int)PAGE_SIZE);
 
-		snprintf(slab_name, sizeof(slab_name), "dm_bufio_cache-%u", block_size);
+		snprintf(slab_name, sizeof(slab_name), "dm_bufio_cache-%u-%u",
+					block_size, atomic_inc_return(&seqno));
 		c->slab_cache = kmem_cache_create(slab_name, block_size, align,
 						  SLAB_RECLAIM_ACCOUNT, NULL);
 		if (!c->slab_cache) {
@@ -2531,9 +2533,11 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
 		}
 	}
 	if (aux_size)
-		snprintf(slab_name, sizeof(slab_name), "dm_bufio_buffer-%u", aux_size);
+		snprintf(slab_name, sizeof(slab_name), "dm_bufio_buffer-%u-%u",
+					aux_size, atomic_inc_return(&seqno));
 	else
-		snprintf(slab_name, sizeof(slab_name), "dm_bufio_buffer");
+		snprintf(slab_name, sizeof(slab_name), "dm_bufio_buffer-%u",
+					atomic_inc_return(&seqno));
 	c->slab_buffer = kmem_cache_create(slab_name, sizeof(struct dm_buffer) + aux_size,
 					   0, SLAB_RECLAIM_ACCOUNT, NULL);
 	if (!c->slab_buffer) {

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

@@ -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

@@ -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

@@ -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);