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, 28 insertions, 4 deletions

diff --git a/drivers/lightnvm/rrpc.h b/drivers/lightnvm/rrpc.h
index c55cec9a1a26..bc8adba4d63f 100644
--- a/drivers/lightnvm/rrpc.h
+++ b/drivers/lightnvm/rrpc.h
@@ -74,7 +74,9 @@ struct rrpc_block {
 
 struct rrpc_lun {
 	struct rrpc *rrpc;
-	struct nvm_lun *parent;
+
+	int id;
+	struct ppa_addr bppa;
 
 	struct rrpc_block *cur, *gc_cur;
 	struct rrpc_block *blocks;	/* Reference to block allocation */
@@ -107,7 +109,6 @@ struct rrpc {
 	struct gendisk *disk;
 
 	sector_t soffset; /* logical sector offset */
-	u64 poffset; /* physical page offset */
 
 	int nr_luns;
 	struct rrpc_lun *luns;
@@ -164,14 +165,37 @@ struct rrpc_rev_addr {
 	u64 addr;
 };
 
+static inline struct ppa_addr rrpc_linear_to_generic_addr(struct nvm_geo *geo,
+							  struct ppa_addr r)
+{
+	struct ppa_addr l;
+	int secs, pgs;
+	sector_t ppa = r.ppa;
+
+	l.ppa = 0;
+
+	div_u64_rem(ppa, geo->sec_per_pg, &secs);
+	l.g.sec = secs;
+
+	sector_div(ppa, geo->sec_per_pg);
+	div_u64_rem(ppa, geo->pgs_per_blk, &pgs);
+	l.g.pg = pgs;
+
+	return l;
+}
+
+static inline struct ppa_addr rrpc_recov_addr(struct nvm_dev *dev, u64 pba)
+{
+	return linear_to_generic_addr(&dev->geo, pba);
+}
+
 static inline u64 rrpc_blk_to_ppa(struct rrpc *rrpc, struct rrpc_block *rblk)
 {
 	struct nvm_tgt_dev *dev = rrpc->dev;
 	struct nvm_geo *geo = &dev->geo;
 	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);
+	return (rlun->id * geo->sec_per_lun) + (rblk->id * geo->sec_per_blk);
 }
 
 static inline sector_t rrpc_get_laddr(struct bio *bio)