lightnvm: add a bitmap of luns

Add a bitmap of luns to indicate the status
of luns: inuse/available. When create targets
do the necessary check to avoid allocating luns
that are already allocated.

Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
Freed dev->lun_map if nvm_core_init later failed in the init process.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/lightnvm/core.c

@@ -464,6 +464,10 @@ static int nvm_core_init(struct nvm_dev *dev)
 	dev->nr_luns = dev->luns_per_chnl * dev->nr_chnls;
 
 	dev->total_secs = dev->nr_luns * dev->sec_per_lun;
+	dev->lun_map = kcalloc(BITS_TO_LONGS(dev->nr_luns),
+					sizeof(unsigned long), GFP_KERNEL);
+	if (!dev->lun_map)
+		return -ENOMEM;
 	INIT_LIST_HEAD(&dev->online_targets);
 	mutex_init(&dev->mlock);
 	spin_lock_init(&dev->lock);
@@ -586,6 +590,7 @@ int nvm_register(struct request_queue *q, char *disk_name,
 
 	return 0;
 err_init:
+	kfree(dev->lun_map);
 	kfree(dev);
 	return ret;
 }
@@ -608,6 +613,7 @@ void nvm_unregister(char *disk_name)
 	up_write(&nvm_lock);
 
 	nvm_exit(dev);
+	kfree(dev->lun_map);
 	kfree(dev);
 }
 EXPORT_SYMBOL(nvm_unregister);

drivers/lightnvm/gennvm.c

@@ -192,6 +192,9 @@ static int gennvm_block_map(u64 slba, u32 nlb, __le64 *entries, void *private)
 		lun_id = div_u64(pba, dev->sec_per_lun);
 		lun = &gn->luns[lun_id];
 
+		if (!test_bit(lun_id, dev->lun_map))
+			__set_bit(lun_id, dev->lun_map);
+
 		/* Calculate block offset into lun */
 		pba = pba - (dev->sec_per_lun * lun_id);
 		blk = &lun->vlun.blocks[div_u64(pba, dev->sec_per_blk)];
@@ -482,10 +485,23 @@ static int gennvm_erase_blk(struct nvm_dev *dev, struct nvm_block *blk,
 	return nvm_erase_ppa(dev, &addr, 1);
 }
 
+static int gennvm_reserve_lun(struct nvm_dev *dev, int lunid)
+{
+	return test_and_set_bit(lunid, dev->lun_map);
+}
+
+static void gennvm_release_lun(struct nvm_dev *dev, int lunid)
+{
+	WARN_ON(!test_and_clear_bit(lunid, dev->lun_map));
+}
+
 static struct nvm_lun *gennvm_get_lun(struct nvm_dev *dev, int lunid)
 {
 	struct gen_nvm *gn = dev->mp;
 
+	if (unlikely(lunid >= dev->nr_luns))
+		return NULL;
+
 	return &gn->luns[lunid].vlun;
 }
 
@@ -527,6 +543,8 @@ static struct nvmm_type gennvm = {
 	.erase_blk		= gennvm_erase_blk,
 
 	.get_lun		= gennvm_get_lun,
+	.reserve_lun		= gennvm_reserve_lun,
+	.release_lun		= gennvm_release_lun,
 	.lun_info_print		= gennvm_lun_info_print,
 
 	.get_area		= gennvm_get_area,

drivers/lightnvm/rrpc.c

@@ -965,25 +965,11 @@ static void rrpc_requeue(struct work_struct *work)
 
 static void rrpc_gc_free(struct rrpc *rrpc)
 {
-	struct rrpc_lun *rlun;
-	int i;
-
 	if (rrpc->krqd_wq)
 		destroy_workqueue(rrpc->krqd_wq);
 
 	if (rrpc->kgc_wq)
 		destroy_workqueue(rrpc->kgc_wq);
-
-	if (!rrpc->luns)
-		return;
-
-	for (i = 0; i < rrpc->nr_luns; i++) {
-		rlun = &rrpc->luns[i];
-
-		if (!rlun->blocks)
-			break;
-		vfree(rlun->blocks);
-	}
 }
 
 static int rrpc_gc_init(struct rrpc *rrpc)
@@ -1143,6 +1129,23 @@ static void rrpc_core_free(struct rrpc *rrpc)
 
 static void rrpc_luns_free(struct rrpc *rrpc)
 {
+	struct nvm_dev *dev = rrpc->dev;
+	struct nvm_lun *lun;
+	struct rrpc_lun *rlun;
+	int i;
+
+	if (!rrpc->luns)
+		return;
+
+	for (i = 0; i < rrpc->nr_luns; i++) {
+		rlun = &rrpc->luns[i];
+		lun = rlun->parent;
+		if (!lun)
+			break;
+		dev->mt->release_lun(dev, lun->id);
+		vfree(rlun->blocks);
+	}
+
 	kfree(rrpc->luns);
 }
 
@@ -1150,7 +1153,7 @@ static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
 {
 	struct nvm_dev *dev = rrpc->dev;
 	struct rrpc_lun *rlun;
-	int i, j;
+	int i, j, ret = -EINVAL;
 
 	if (dev->sec_per_blk > MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
 		pr_err("rrpc: number of pages per block too high.");
@@ -1166,25 +1169,26 @@ static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
 
 	/* 1:1 mapping */
 	for (i = 0; i < rrpc->nr_luns; i++) {
-		struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i);
+		int lunid = lun_begin + i;
+		struct nvm_lun *lun;
+
+		if (dev->mt->reserve_lun(dev, lunid)) {
+			pr_err("rrpc: lun %u is already allocated\n", lunid);
+			goto err;
+		}
+
+		lun = dev->mt->get_lun(dev, lunid);
+		if (!lun)
+			goto err;
 
 		rlun = &rrpc->luns[i];
-		rlun->rrpc = rrpc;
 		rlun->parent = lun;
-		INIT_LIST_HEAD(&rlun->prio_list);
-		INIT_LIST_HEAD(&rlun->open_list);
-		INIT_LIST_HEAD(&rlun->closed_list);
-
-		INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
-		spin_lock_init(&rlun->lock);
-
-		rrpc->total_blocks += dev->blks_per_lun;
-		rrpc->nr_sects += dev->sec_per_lun;
-
 		rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
 						rrpc->dev->blks_per_lun);
-		if (!rlun->blocks)
+		if (!rlun->blocks) {
+			ret = -ENOMEM;
 			goto err;
+		}
 
 		for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
 			struct rrpc_block *rblk = &rlun->blocks[j];
@@ -1195,11 +1199,23 @@ static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
 			INIT_LIST_HEAD(&rblk->prio);
 			spin_lock_init(&rblk->lock);
 		}
+
+		rlun->rrpc = rrpc;
+		INIT_LIST_HEAD(&rlun->prio_list);
+		INIT_LIST_HEAD(&rlun->open_list);
+		INIT_LIST_HEAD(&rlun->closed_list);
+
+		INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
+		spin_lock_init(&rlun->lock);
+
+		rrpc->total_blocks += dev->blks_per_lun;
+		rrpc->nr_sects += dev->sec_per_lun;
+
 	}
 
 	return 0;
 err:
-	return -ENOMEM;
+	return ret;
 }
 
 /* returns 0 on success and stores the beginning address in *begin */

include/linux/lightnvm.h

@@ -346,6 +346,7 @@ struct nvm_dev {
 	int nr_luns;
 	unsigned max_pages_per_blk;
 
+	unsigned long *lun_map;
 	void *ppalist_pool;
 
 	struct nvm_id identity;
@@ -466,6 +467,8 @@ typedef int (nvmm_submit_io_fn)(struct nvm_dev *, struct nvm_rq *);
 typedef int (nvmm_erase_blk_fn)(struct nvm_dev *, struct nvm_block *,
 								unsigned long);
 typedef struct nvm_lun *(nvmm_get_lun_fn)(struct nvm_dev *, int);
+typedef int (nvmm_reserve_lun)(struct nvm_dev *, int);
+typedef void (nvmm_release_lun)(struct nvm_dev *, int);
 typedef void (nvmm_lun_info_print_fn)(struct nvm_dev *);
 
 typedef int (nvmm_get_area_fn)(struct nvm_dev *, sector_t *, sector_t);
@@ -492,6 +495,8 @@ struct nvmm_type {
 
 	/* Configuration management */
 	nvmm_get_lun_fn *get_lun;
+	nvmm_reserve_lun *reserve_lun;
+	nvmm_release_lun *release_lun;
 
 	/* Statistics */
 	nvmm_lun_info_print_fn *lun_info_print;