lightnvm: eliminate nvm_lun abstraction in mm

In order to naturally support multi-target instances on an Open-Channel
SSD, targets should own the LUNs they get blocks from and manage
provisioning internally. This is done in several steps.

Since targets own the LUNs the are instantiated on top of and manage the
free block list internally, there is no need for a LUN abstraction in
the media manager. LUNs are intrinsically managed as in the physical
layout (ch:0,lun:0, ..., ch:0,lun:n, ch:1,lun:0, ch:1,lun:n, ...,
ch:m,lun:0, ch:m,lun:n) and given to the targets based on the target
creation ioctl. This simplifies LUN management and clears the path for a
partition manager to sit directly underneath LightNVM targets.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 68 insertions, 69 deletions

diff --git a/drivers/lightnvm/rrpc.c b/drivers/lightnvm/rrpc.c
index a352285dffc0..75ed12ae0f47 100644
--- a/drivers/lightnvm/rrpc.c
+++ b/drivers/lightnvm/rrpc.c
@@ -45,7 +45,7 @@ static void rrpc_page_invalidate(struct rrpc *rrpc, struct rrpc_addr *a)
 
 	spin_unlock(&rblk->lock);
 
-	rrpc->rev_trans_map[a->addr - rrpc->poffset].addr = ADDR_EMPTY;
+	rrpc->rev_trans_map[a->addr].addr = ADDR_EMPTY;
 }
 
 static void rrpc_invalidate_range(struct rrpc *rrpc, sector_t slba,
@@ -127,28 +127,25 @@ static u64 block_to_rel_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 {
 	struct nvm_tgt_dev *dev = rrpc->dev;
 	struct rrpc_lun *rlun = rblk->rlun;
-	struct nvm_lun *lun = rlun->parent;
 
-	return lun->id * dev->geo.sec_per_blk;
+	return rlun->id * dev->geo.sec_per_blk;
 }
 
-/* Calculate global addr for the given block */
-static u64 block_to_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
+static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_tgt_dev *dev,
+					 struct rrpc_addr *gp)
 {
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct nvm_geo *geo = &dev->geo;
+	struct rrpc_block *rblk = gp->rblk;
 	struct rrpc_lun *rlun = rblk->rlun;
-	struct nvm_lun *lun = rlun->parent;
-
-	return lun->id * geo->sec_per_lun + rblk->id * geo->sec_per_blk;
-}
-
-static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_tgt_dev *dev, u64 addr)
-{
+	u64 addr = gp->addr;
 	struct ppa_addr paddr;
 
 	paddr.ppa = addr;
-	return linear_to_generic_addr(&dev->geo, paddr);
+	paddr = rrpc_linear_to_generic_addr(&dev->geo, paddr);
+	paddr.g.ch = rlun->bppa.g.ch;
+	paddr.g.lun = rlun->bppa.g.lun;
+	paddr.g.blk = rblk->id;
+
+	return paddr;
 }
 
 /* requires lun->lock taken */
@@ -216,7 +213,6 @@ static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
 static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 {
 	struct rrpc_lun *rlun = rblk->rlun;
-	struct nvm_lun *lun = rlun->parent;
 
 	spin_lock(&rlun->lock);
 	if (rblk->state & NVM_BLK_ST_TGT) {
@@ -229,8 +225,8 @@ static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 	} else {
 		WARN_ON_ONCE(1);
 		pr_err("rrpc: erroneous type (ch:%d,lun:%d,blk%d-> %u)\n",
-						lun->chnl_id, lun->lun_id,
-						rblk->id, rblk->state);
+					rlun->bppa.g.ch, rlun->bppa.g.lun,
+					rblk->id, rblk->state);
 		list_move_tail(&rblk->list, &rlun->bb_list);
 	}
 	spin_unlock(&rlun->lock);
@@ -336,7 +332,7 @@ static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
 try:
 		spin_lock(&rrpc->rev_lock);
 		/* Get logical address from physical to logical table */
-		rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
+		rev = &rrpc->rev_trans_map[phys_addr];
 		/* already updated by previous regular write */
 		if (rev->addr == ADDR_EMPTY) {
 			spin_unlock(&rrpc->rev_lock);
@@ -423,18 +419,18 @@ static void rrpc_block_gc(struct work_struct *work)
 
 	mempool_free(gcb, rrpc->gcb_pool);
 	pr_debug("nvm: block 'ch:%d,lun:%d,blk:%d' being reclaimed\n",
-			rlun->parent->chnl_id, rlun->parent->lun_id,
+			rlun->bppa.g.ch, rlun->bppa.g.lun,
 			rblk->id);
 
 	if (rrpc_move_valid_pages(rrpc, rblk))
 		goto put_back;
 
 	ppa.ppa = 0;
-	ppa.g.ch = rlun->parent->chnl_id;
-	ppa.g.lun = rlun->parent->lun_id;
+	ppa.g.ch = rlun->bppa.g.ch;
+	ppa.g.lun = rlun->bppa.g.lun;
 	ppa.g.blk = rblk->id;
 
-	if (nvm_erase_blk(dev->parent, &ppa, 0))
+	if (nvm_erase_blk(dev, &ppa, 0))
 		goto put_back;
 
 	rrpc_put_blk(rrpc, rblk);
@@ -506,8 +502,7 @@ static void rrpc_lun_gc(struct work_struct *work)
 		WARN_ON(!block_is_full(rrpc, rblk));
 
 		pr_debug("rrpc: selected block 'ch:%d,lun:%d,blk:%d' for GC\n",
-					rlun->parent->chnl_id,
-					rlun->parent->lun_id,
+					rlun->bppa.g.ch, rlun->bppa.g.lun,
 					rblk->id);
 
 		gcb->rrpc = rrpc;
@@ -537,8 +532,7 @@ static void rrpc_gc_queue(struct work_struct *work)
 
 	mempool_free(gcb, rrpc->gcb_pool);
 	pr_debug("nvm: block 'ch:%d,lun:%d,blk:%d' full, allow GC (sched)\n",
-					rlun->parent->chnl_id,
-					rlun->parent->lun_id,
+					rlun->bppa.g.ch, rlun->bppa.g.lun,
 					rblk->id);
 }
 
@@ -586,7 +580,7 @@ static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
 	gp->addr = paddr;
 	gp->rblk = rblk;
 
-	rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset];
+	rev = &rrpc->rev_trans_map[gp->addr];
 	rev->addr = laddr;
 	spin_unlock(&rrpc->rev_lock);
 
@@ -601,7 +595,7 @@ static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
 	if (block_is_full(rrpc, rblk))
 		goto out;
 
-	addr = block_to_addr(rrpc, rblk) + rblk->next_page;
+	addr = rblk->next_page;
 
 	rblk->next_page++;
 out:
@@ -615,18 +609,22 @@ out:
  * Returns rrpc_addr with the physical address and block. Returns NULL if no
  * blocks in the next rlun are available.
  */
-static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
+static struct ppa_addr rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
 								int is_gc)
 {
+	struct nvm_tgt_dev *tgt_dev = rrpc->dev;
 	struct rrpc_lun *rlun;
 	struct rrpc_block *rblk, **cur_rblk;
+	struct rrpc_addr *p;
+	struct ppa_addr ppa;
 	u64 paddr;
 	int gc_force = 0;
 
+	ppa.ppa = ADDR_EMPTY;
 	rlun = rrpc_get_lun_rr(rrpc, is_gc);
 
 	if (!is_gc && rlun->nr_free_blocks < rrpc->nr_luns * 4)
-		return NULL;
+		return ppa;
 
 	/*
 	 * page allocation steps:
@@ -683,10 +681,15 @@ new_blk:
 	}
 
 	pr_err("rrpc: failed to allocate new block\n");
-	return NULL;
+	return ppa;
 done:
 	spin_unlock(&rlun->lock);
-	return rrpc_update_map(rrpc, laddr, rblk, paddr);
+	p = rrpc_update_map(rrpc, laddr, rblk, paddr);
+	if (!p)
+		return ppa;
+
+	/* return global address */
+	return rrpc_ppa_to_gaddr(tgt_dev, p);
 }
 
 static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
@@ -712,8 +715,8 @@ static struct rrpc_lun *rrpc_ppa_to_lun(struct rrpc *rrpc, struct ppa_addr p)
 	int i;
 
 	for (i = 0; i < rrpc->nr_luns; i++) {
-		if (rrpc->luns[i].parent->chnl_id == p.g.ch &&
-				rrpc->luns[i].parent->lun_id == p.g.lun) {
+		if (rrpc->luns[i].bppa.g.ch == p.g.ch &&
+				rrpc->luns[i].bppa.g.lun == p.g.lun) {
 			rlun = &rrpc->luns[i];
 			break;
 		}
@@ -823,7 +826,7 @@ static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 		gp = &rrpc->trans_map[laddr + i];
 
 		if (gp->rblk) {
-			rqd->ppa_list[i] = rrpc_ppa_to_gaddr(dev, gp->addr);
+			rqd->ppa_list[i] = rrpc_ppa_to_gaddr(dev, gp);
 		} else {
 			BUG_ON(is_gc);
 			rrpc_unlock_laddr(rrpc, r);
@@ -852,7 +855,7 @@ static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
 	gp = &rrpc->trans_map[laddr];
 
 	if (gp->rblk) {
-		rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
+		rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp);
 	} else {
 		BUG_ON(is_gc);
 		rrpc_unlock_rq(rrpc, rqd);
@@ -869,7 +872,7 @@ static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 {
 	struct nvm_tgt_dev *dev = rrpc->dev;
 	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
-	struct rrpc_addr *p;
+	struct ppa_addr p;
 	sector_t laddr = rrpc_get_laddr(bio);
 	int is_gc = flags & NVM_IOTYPE_GC;
 	int i;
@@ -882,7 +885,7 @@ static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 	for (i = 0; i < npages; i++) {
 		/* We assume that mapping occurs at 4KB granularity */
 		p = rrpc_map_page(rrpc, laddr + i, is_gc);
-		if (!p) {
+		if (p.ppa == ADDR_EMPTY) {
 			BUG_ON(is_gc);
 			rrpc_unlock_laddr(rrpc, r);
 			nvm_dev_dma_free(dev->parent, rqd->ppa_list,
@@ -891,7 +894,7 @@ static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 			return NVM_IO_REQUEUE;
 		}
 
-		rqd->ppa_list[i] = rrpc_ppa_to_gaddr(dev, p->addr);
+		rqd->ppa_list[i] = p;
 	}
 
 	rqd->opcode = NVM_OP_HBWRITE;
@@ -902,7 +905,7 @@ static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
 static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
 				struct nvm_rq *rqd, unsigned long flags)
 {
-	struct rrpc_addr *p;
+	struct ppa_addr p;
 	int is_gc = flags & NVM_IOTYPE_GC;
 	sector_t laddr = rrpc_get_laddr(bio);
 
@@ -910,14 +913,14 @@ static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
 		return NVM_IO_REQUEUE;
 
 	p = rrpc_map_page(rrpc, laddr, is_gc);
-	if (!p) {
+	if (p.ppa == ADDR_EMPTY) {
 		BUG_ON(is_gc);
 		rrpc_unlock_rq(rrpc, rqd);
 		rrpc_gc_kick(rrpc);
 		return NVM_IO_REQUEUE;
 	}
 
-	rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
+	rqd->ppa_addr = p;
 	rqd->opcode = NVM_OP_HBWRITE;
 
 	return NVM_IO_OK;
@@ -973,7 +976,7 @@ static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
 	rqd->nr_ppas = nr_pages;
 	rrq->flags = flags;
 
-	err = nvm_submit_io(dev->parent, rqd);
+	err = nvm_submit_io(dev, rqd);
 	if (err) {
 		pr_err("rrpc: I/O submission failed: %d\n", err);
 		bio_put(bio);
@@ -1113,10 +1116,7 @@ static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
 
 		div_u64_rem(pba, rrpc->nr_sects, &mod);
 
-		addr[i].addr = pba;
-		raddr[mod].addr = slba + i;
-
-		gaddr = rrpc_ppa_to_gaddr(dev, pba);
+		gaddr = rrpc_recov_addr(dev->parent, pba);
 		rlun = rrpc_ppa_to_lun(rrpc, gaddr);
 		if (!rlun) {
 			pr_err("rrpc: l2p corruption on lba %llu\n",
@@ -1134,6 +1134,10 @@ static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
 			rblk->state = NVM_BLK_ST_TGT;
 			rlun->nr_free_blocks--;
 		}
+
+		addr[i].addr = pba;
+		addr[i].rblk = rblk;
+		raddr[mod].addr = slba + i;
 	}
 
 	return 0;
@@ -1230,7 +1234,6 @@ static void rrpc_core_free(struct rrpc *rrpc)
 
 static void rrpc_luns_free(struct rrpc *rrpc)
 {
-	struct nvm_lun *lun;
 	struct rrpc_lun *rlun;
 	int i;
 
@@ -1239,9 +1242,6 @@ static void rrpc_luns_free(struct rrpc *rrpc)
 
 	for (i = 0; i < rrpc->nr_luns; i++) {
 		rlun = &rrpc->luns[i];
-		lun = rlun->parent;
-		if (!lun)
-			break;
 		vfree(rlun->blocks);
 	}
 
@@ -1264,8 +1264,8 @@ static int rrpc_bb_discovery(struct nvm_tgt_dev *dev, struct rrpc_lun *rlun)
 		return -ENOMEM;
 
 	ppa.ppa = 0;
-	ppa.g.ch = rlun->parent->chnl_id;
-	ppa.g.lun = rlun->parent->lun_id;
+	ppa.g.ch = rlun->bppa.g.ch;
+	ppa.g.lun = rlun->bppa.g.lun;
 
 	ret = nvm_get_bb_tbl(dev->parent, ppa, blks);
 	if (ret) {
@@ -1293,11 +1293,17 @@ out:
 	return ret;
 }
 
-static int rrpc_luns_init(struct rrpc *rrpc, struct list_head *lun_list)
+static void rrpc_set_lun_ppa(struct rrpc_lun *rlun, struct ppa_addr ppa)
+{
+	rlun->bppa.ppa = 0;
+	rlun->bppa.g.ch = ppa.g.ch;
+	rlun->bppa.g.lun = ppa.g.lun;
+}
+
+static int rrpc_luns_init(struct rrpc *rrpc, struct ppa_addr *luns)
 {
 	struct nvm_tgt_dev *dev = rrpc->dev;
 	struct nvm_geo *geo = &dev->geo;
-	struct nvm_lun *lun;
 	struct rrpc_lun *rlun;
 	int i, j, ret = -EINVAL;
 
@@ -1313,12 +1319,11 @@ static int rrpc_luns_init(struct rrpc *rrpc, struct list_head *lun_list)
 	if (!rrpc->luns)
 		return -ENOMEM;
 
-	i = 0;
-
 	/* 1:1 mapping */
-	list_for_each_entry(lun, lun_list, list) {
-		rlun = &rrpc->luns[i++];
-		rlun->parent = lun;
+	for (i = 0; i < rrpc->nr_luns; i++) {
+		rlun = &rrpc->luns[i];
+		rlun->id = i;
+		rrpc_set_lun_ppa(rlun, luns[i]);
 		rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
 							geo->blks_per_lun);
 		if (!rlun->blocks) {
@@ -1356,8 +1361,6 @@ static int rrpc_luns_init(struct rrpc *rrpc, struct list_head *lun_list)
 		spin_lock_init(&rlun->lock);
 	}
 
-	WARN_ON(i != rrpc->nr_luns);
-
 	return 0;
 err:
 	return ret;
@@ -1511,14 +1514,12 @@ err:
 
 static struct nvm_tgt_type tt_rrpc;
 
-static void *rrpc_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
-						struct list_head *lun_list)
+static void *rrpc_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk)
 {
 	struct request_queue *bqueue = dev->q;
 	struct request_queue *tqueue = tdisk->queue;
 	struct nvm_geo *geo = &dev->geo;
 	struct rrpc *rrpc;
-	int lun_begin = (list_first_entry(lun_list, struct nvm_lun, list))->id;
 	sector_t soffset;
 	int ret;
 
@@ -1553,14 +1554,12 @@ static void *rrpc_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
 	}
 	rrpc->soffset = soffset;
 
-	ret = rrpc_luns_init(rrpc, lun_list);
+	ret = rrpc_luns_init(rrpc, dev->luns);
 	if (ret) {
 		pr_err("nvm: rrpc: could not initialize luns\n");
 		goto err;
 	}
 
-	rrpc->poffset = geo->sec_per_lun * lun_begin;
-
 	ret = rrpc_core_init(rrpc);
 	if (ret) {
 		pr_err("nvm: rrpc: could not initialize core\n");