[PATCH 4/7] lightnvm: pblk: move global caches to module init/exit

[Hans Holmberg <hans.ml.holmberg@owltronix.com>]

From: Hans Holmberg <hans.holmberg@cnexlabs.com>

Pblk's global caches should not be initialized every time
a pblk instance is created, so move the creation and destruction
of the caches to module init/exit.

Also remove the global pblk lock as it is no longer needed after
the move.

Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
---
 drivers/lightnvm/pblk-init.c | 42 ++++++++++++++++++++----------------------
 1 file changed, 20 insertions(+), 22 deletions(-)

diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index 76a4a271b9cf..0be64220b5d8 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -27,7 +27,6 @@ MODULE_PARM_DESC(write_buffer_size, "number of entries in a write buffer");
 
 static struct kmem_cache *pblk_ws_cache, *pblk_rec_cache, *pblk_g_rq_cache,
 				*pblk_w_rq_cache;
-static DECLARE_RWSEM(pblk_lock);
 struct bio_set pblk_bio_set;
 
 static int pblk_rw_io(struct request_queue *q, struct pblk *pblk,
@@ -306,21 +305,17 @@ static int pblk_set_addrf(struct pblk *pblk)
 	return 0;
 }
 
-static int pblk_init_global_caches(struct pblk *pblk)
+static int pblk_init_global_caches(void)
 {
-	down_write(&pblk_lock);
 	pblk_ws_cache = kmem_cache_create("pblk_blk_ws",
 				sizeof(struct pblk_line_ws), 0, 0, NULL);
-	if (!pblk_ws_cache) {
-		up_write(&pblk_lock);
+	if (!pblk_ws_cache)
 		return -ENOMEM;
-	}
 
 	pblk_rec_cache = kmem_cache_create("pblk_rec",
 				sizeof(struct pblk_rec_ctx), 0, 0, NULL);
 	if (!pblk_rec_cache) {
 		kmem_cache_destroy(pblk_ws_cache);
-		up_write(&pblk_lock);
 		return -ENOMEM;
 	}
 
@@ -329,7 +324,6 @@ static int pblk_init_global_caches(struct pblk *pblk)
 	if (!pblk_g_rq_cache) {
 		kmem_cache_destroy(pblk_ws_cache);
 		kmem_cache_destroy(pblk_rec_cache);
-		up_write(&pblk_lock);
 		return -ENOMEM;
 	}
 
@@ -339,15 +333,13 @@ static int pblk_init_global_caches(struct pblk *pblk)
 		kmem_cache_destroy(pblk_ws_cache);
 		kmem_cache_destroy(pblk_rec_cache);
 		kmem_cache_destroy(pblk_g_rq_cache);
-		up_write(&pblk_lock);
 		return -ENOMEM;
 	}
-	up_write(&pblk_lock);
 
 	return 0;
 }
 
-static void pblk_free_global_caches(struct pblk *pblk)
+static void pblk_free_global_caches(void)
 {
 	kmem_cache_destroy(pblk_ws_cache);
 	kmem_cache_destroy(pblk_rec_cache);
@@ -381,13 +373,10 @@ static int pblk_core_init(struct pblk *pblk)
 	if (!pblk->pad_dist)
 		return -ENOMEM;
 
-	if (pblk_init_global_caches(pblk))
-		goto fail_free_pad_dist;
-
 	/* Internal bios can be at most the sectors signaled by the device. */
 	ret = mempool_init_page_pool(&pblk->page_bio_pool, NVM_MAX_VLBA, 0);
 	if (ret)
-		goto free_global_caches;
+		goto free_pad_dist;
 
 	ret = mempool_init_slab_pool(&pblk->gen_ws_pool, PBLK_GEN_WS_POOL_SIZE,
 				     pblk_ws_cache);
@@ -455,9 +444,7 @@ static int pblk_core_init(struct pblk *pblk)
 	mempool_exit(&pblk->gen_ws_pool);
 free_page_bio_pool:
 	mempool_exit(&pblk->page_bio_pool);
-free_global_caches:
-	pblk_free_global_caches(pblk);
-fail_free_pad_dist:
+free_pad_dist:
 	kfree(pblk->pad_dist);
 	return -ENOMEM;
 }
@@ -480,7 +467,6 @@ static void pblk_core_free(struct pblk *pblk)
 	mempool_exit(&pblk->e_rq_pool);
 	mempool_exit(&pblk->w_rq_pool);
 
-	pblk_free_global_caches(pblk);
 	kfree(pblk->pad_dist);
 }
 
@@ -1067,7 +1053,6 @@ static void pblk_exit(void *private, bool graceful)
 {
 	struct pblk *pblk = private;
 
-	down_write(&pblk_lock);
 	pblk_gc_exit(pblk, graceful);
 	pblk_tear_down(pblk, graceful);
 
@@ -1076,7 +1061,6 @@ static void pblk_exit(void *private, bool graceful)
 #endif
 
 	pblk_free(pblk);
-	up_write(&pblk_lock);
 }
 
 static sector_t pblk_capacity(void *private)
@@ -1237,9 +1221,22 @@ static int __init pblk_module_init(void)
 	ret = bioset_init(&pblk_bio_set, BIO_POOL_SIZE, 0, 0);
 	if (ret)
 		return ret;
+
 	ret = nvm_register_tgt_type(&tt_pblk);
 	if (ret)
-		bioset_exit(&pblk_bio_set);
+		goto fail_exit_bioset;
+
+	ret = pblk_init_global_caches();
+	if (ret)
+		goto fail_unregister_tgt_type;
+
+	return 0;
+
+fail_unregister_tgt_type:
+	nvm_unregister_tgt_type(&tt_pblk);
+fail_exit_bioset:
+	bioset_exit(&pblk_bio_set);
+
 	return ret;
 }
 
@@ -1247,6 +1244,7 @@ static void pblk_module_exit(void)
 {
 	bioset_exit(&pblk_bio_set);
 	nvm_unregister_tgt_type(&tt_pblk);
+	pblk_free_global_caches();
 }
 
 module_init(pblk_module_init);
-- 
2.7.4