lightnvm: remove rrpc

The hybrid mode for 1.2 revision was deprecated, and have
no users. Remove to make it easier to move to the 2.0 revision.

Signed-off-by: Matias Bjørling <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/lightnvm/Kconfig

···
 
 	It is required to create/remove targets without IOCTLs.
 
-config NVM_RRPC
-	tristate "Round-robin Hybrid Open-Channel SSD target"
-	---help---
-	Allows an open-channel SSD to be exposed as a block device to the
-	host. The target is implemented using a linear mapping table and
-	cost-based garbage collection. It is optimized for 4K IO sizes.
-
 config NVM_PBLK
 	tristate "Physical Block Device Open-Channel SSD target"
 	---help---

drivers/lightnvm/Makefile

···
 #
 
 obj-$(CONFIG_NVM)		:= core.o
-obj-$(CONFIG_NVM_RRPC)		+= rrpc.o
 obj-$(CONFIG_NVM_PBLK)		+= pblk.o
 pblk-y				:= pblk-init.o pblk-core.o pblk-rb.o \
 				   pblk-write.o pblk-cache.o pblk-read.o \

drivers/lightnvm/rrpc.c

···
-/*
- * Copyright (C) 2015 IT University of Copenhagen
- * Initial release: Matias Bjorling <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs.
- */
-
-#include "rrpc.h"
-
-static struct kmem_cache *rrpc_gcb_cache, *rrpc_rq_cache;
-static DECLARE_RWSEM(rrpc_lock);
-
-static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
-				struct nvm_rq *rqd, unsigned long flags);
-
-#define rrpc_for_each_lun(rrpc, rlun, i) \
-		for ((i) = 0, rlun = &(rrpc)->luns[0]; \
-			(i) < (rrpc)->nr_luns; (i)++, rlun = &(rrpc)->luns[(i)])
-
-static void rrpc_page_invalidate(struct rrpc *rrpc, struct rrpc_addr *a)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_block *rblk = a->rblk;
-	unsigned int pg_offset;
-
-	lockdep_assert_held(&rrpc->rev_lock);
-
-	if (a->addr == ADDR_EMPTY || !rblk)
-		return;
-
-	spin_lock(&rblk->lock);
-
-	div_u64_rem(a->addr, dev->geo.sec_per_blk, &pg_offset);
-	WARN_ON(test_and_set_bit(pg_offset, rblk->invalid_pages));
-	rblk->nr_invalid_pages++;
-
-	spin_unlock(&rblk->lock);
-
-	rrpc->rev_trans_map[a->addr].addr = ADDR_EMPTY;
-}
-
-static void rrpc_invalidate_range(struct rrpc *rrpc, sector_t slba,
-							unsigned int len)
-{
-	sector_t i;
-
-	spin_lock(&rrpc->rev_lock);
-	for (i = slba; i < slba + len; i++) {
-		struct rrpc_addr *gp = &rrpc->trans_map[i];
-
-		rrpc_page_invalidate(rrpc, gp);
-		gp->rblk = NULL;
-	}
-	spin_unlock(&rrpc->rev_lock);
-}
-
-static struct nvm_rq *rrpc_inflight_laddr_acquire(struct rrpc *rrpc,
-					sector_t laddr, unsigned int pages)
-{
-	struct nvm_rq *rqd;
-	struct rrpc_inflight_rq *inf;
-
-	rqd = mempool_alloc(rrpc->rq_pool, GFP_ATOMIC);
-	if (!rqd)
-		return ERR_PTR(-ENOMEM);
-
-	inf = rrpc_get_inflight_rq(rqd);
-	if (rrpc_lock_laddr(rrpc, laddr, pages, inf)) {
-		mempool_free(rqd, rrpc->rq_pool);
-		return NULL;
-	}
-
-	return rqd;
-}
-
-static void rrpc_inflight_laddr_release(struct rrpc *rrpc, struct nvm_rq *rqd)
-{
-	struct rrpc_inflight_rq *inf = rrpc_get_inflight_rq(rqd);
-
-	rrpc_unlock_laddr(rrpc, inf);
-
-	mempool_free(rqd, rrpc->rq_pool);
-}
-
-static void rrpc_discard(struct rrpc *rrpc, struct bio *bio)
-{
-	sector_t slba = bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
-	sector_t len = bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
-	struct nvm_rq *rqd;
-
-	while (1) {
-		rqd = rrpc_inflight_laddr_acquire(rrpc, slba, len);
-		if (rqd)
-			break;
-
-		schedule();
-	}
-
-	if (IS_ERR(rqd)) {
-		pr_err("rrpc: unable to acquire inflight IO\n");
-		bio_io_error(bio);
-		return;
-	}
-
-	rrpc_invalidate_range(rrpc, slba, len);
-	rrpc_inflight_laddr_release(rrpc, rqd);
-}
-
-static int block_is_full(struct rrpc *rrpc, struct rrpc_block *rblk)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-
-	return (rblk->next_page == dev->geo.sec_per_blk);
-}
-
-/* Calculate relative addr for the given block, considering instantiated LUNs */
-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;
-
-	return rlun->id * dev->geo.sec_per_blk;
-}
-
-static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_tgt_dev *dev,
-					 struct rrpc_addr *gp)
-{
-	struct rrpc_block *rblk = gp->rblk;
-	struct rrpc_lun *rlun = rblk->rlun;
-	u64 addr = gp->addr;
-	struct ppa_addr paddr;
-
-	paddr.ppa = addr;
-	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 */
-static void rrpc_set_lun_cur(struct rrpc_lun *rlun, struct rrpc_block *new_rblk,
-						struct rrpc_block **cur_rblk)
-{
-	struct rrpc *rrpc = rlun->rrpc;
-
-	if (*cur_rblk) {
-		spin_lock(&(*cur_rblk)->lock);
-		WARN_ON(!block_is_full(rrpc, *cur_rblk));
-		spin_unlock(&(*cur_rblk)->lock);
-	}
-	*cur_rblk = new_rblk;
-}
-
-static struct rrpc_block *__rrpc_get_blk(struct rrpc *rrpc,
-							struct rrpc_lun *rlun)
-{
-	struct rrpc_block *rblk = NULL;
-
-	if (list_empty(&rlun->free_list))
-		goto out;
-
-	rblk = list_first_entry(&rlun->free_list, struct rrpc_block, list);
-
-	list_move_tail(&rblk->list, &rlun->used_list);
-	rblk->state = NVM_BLK_ST_TGT;
-	rlun->nr_free_blocks--;
-
-out:
-	return rblk;
-}
-
-static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
-							unsigned long flags)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_block *rblk;
-	int is_gc = flags & NVM_IOTYPE_GC;
-
-	spin_lock(&rlun->lock);
-	if (!is_gc && rlun->nr_free_blocks < rlun->reserved_blocks) {
-		pr_err("nvm: rrpc: cannot give block to non GC request\n");
-		spin_unlock(&rlun->lock);
-		return NULL;
-	}
-
-	rblk = __rrpc_get_blk(rrpc, rlun);
-	if (!rblk) {
-		pr_err("nvm: rrpc: cannot get new block\n");
-		spin_unlock(&rlun->lock);
-		return NULL;
-	}
-	spin_unlock(&rlun->lock);
-
-	bitmap_zero(rblk->invalid_pages, dev->geo.sec_per_blk);
-	rblk->next_page = 0;
-	rblk->nr_invalid_pages = 0;
-	atomic_set(&rblk->data_cmnt_size, 0);
-
-	return rblk;
-}
-
-static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
-{
-	struct rrpc_lun *rlun = rblk->rlun;
-
-	spin_lock(&rlun->lock);
-	if (rblk->state & NVM_BLK_ST_TGT) {
-		list_move_tail(&rblk->list, &rlun->free_list);
-		rlun->nr_free_blocks++;
-		rblk->state = NVM_BLK_ST_FREE;
-	} else if (rblk->state & NVM_BLK_ST_BAD) {
-		list_move_tail(&rblk->list, &rlun->bb_list);
-		rblk->state = NVM_BLK_ST_BAD;
-	} else {
-		WARN_ON_ONCE(1);
-		pr_err("rrpc: erroneous type (ch:%d,lun:%d,blk%d-> %u)\n",
-					rlun->bppa.g.ch, rlun->bppa.g.lun,
-					rblk->id, rblk->state);
-		list_move_tail(&rblk->list, &rlun->bb_list);
-	}
-	spin_unlock(&rlun->lock);
-}
-
-static void rrpc_put_blks(struct rrpc *rrpc)
-{
-	struct rrpc_lun *rlun;
-	int i;
-
-	for (i = 0; i < rrpc->nr_luns; i++) {
-		rlun = &rrpc->luns[i];
-		if (rlun->cur)
-			rrpc_put_blk(rrpc, rlun->cur);
-		if (rlun->gc_cur)
-			rrpc_put_blk(rrpc, rlun->gc_cur);
-	}
-}
-
-static struct rrpc_lun *get_next_lun(struct rrpc *rrpc)
-{
-	int next = atomic_inc_return(&rrpc->next_lun);
-
-	return &rrpc->luns[next % rrpc->nr_luns];
-}
-
-static void rrpc_gc_kick(struct rrpc *rrpc)
-{
-	struct rrpc_lun *rlun;
-	unsigned int i;
-
-	for (i = 0; i < rrpc->nr_luns; i++) {
-		rlun = &rrpc->luns[i];
-		queue_work(rrpc->krqd_wq, &rlun->ws_gc);
-	}
-}
-
-/*
- * timed GC every interval.
- */
-static void rrpc_gc_timer(struct timer_list *t)
-{
-	struct rrpc *rrpc = from_timer(rrpc, t, gc_timer);
-
-	rrpc_gc_kick(rrpc);
-	mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
-}
-
-static void rrpc_end_sync_bio(struct bio *bio)
-{
-	struct completion *waiting = bio->bi_private;
-
-	if (bio->bi_status)
-		pr_err("nvm: gc request failed (%u).\n", bio->bi_status);
-
-	complete(waiting);
-}
-
-/*
- * rrpc_move_valid_pages -- migrate live data off the block
- * @rrpc: the 'rrpc' structure
- * @block: the block from which to migrate live pages
- *
- * Description:
- *   GC algorithms may call this function to migrate remaining live
- *   pages off the block prior to erasing it. This function blocks
- *   further execution until the operation is complete.
- */
-static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct request_queue *q = dev->q;
-	struct rrpc_rev_addr *rev;
-	struct nvm_rq *rqd;
-	struct bio *bio;
-	struct page *page;
-	int slot;
-	int nr_sec_per_blk = dev->geo.sec_per_blk;
-	u64 phys_addr;
-	DECLARE_COMPLETION_ONSTACK(wait);
-
-	if (bitmap_full(rblk->invalid_pages, nr_sec_per_blk))
-		return 0;
-
-	bio = bio_alloc(GFP_NOIO, 1);
-	if (!bio) {
-		pr_err("nvm: could not alloc bio to gc\n");
-		return -ENOMEM;
-	}
-
-	page = mempool_alloc(rrpc->page_pool, GFP_NOIO);
-
-	while ((slot = find_first_zero_bit(rblk->invalid_pages,
-					    nr_sec_per_blk)) < nr_sec_per_blk) {
-
-		/* Lock laddr */
-		phys_addr = rrpc_blk_to_ppa(rrpc, rblk) + slot;
-
-try:
-		spin_lock(&rrpc->rev_lock);
-		/* Get logical address from physical to logical table */
-		rev = &rrpc->rev_trans_map[phys_addr];
-		/* already updated by previous regular write */
-		if (rev->addr == ADDR_EMPTY) {
-			spin_unlock(&rrpc->rev_lock);
-			continue;
-		}
-
-		rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
-		if (IS_ERR_OR_NULL(rqd)) {
-			spin_unlock(&rrpc->rev_lock);
-			schedule();
-			goto try;
-		}
-
-		spin_unlock(&rrpc->rev_lock);
-
-		/* Perform read to do GC */
-		bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
-		bio_set_op_attrs(bio,  REQ_OP_READ, 0);
-		bio->bi_private = &wait;
-		bio->bi_end_io = rrpc_end_sync_bio;
-
-		/* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
-		bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
-
-		if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
-			pr_err("rrpc: gc read failed.\n");
-			rrpc_inflight_laddr_release(rrpc, rqd);
-			goto finished;
-		}
-		wait_for_completion_io(&wait);
-		if (bio->bi_status) {
-			rrpc_inflight_laddr_release(rrpc, rqd);
-			goto finished;
-		}
-
-		bio_reset(bio);
-		reinit_completion(&wait);
-
-		bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
-		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
-		bio->bi_private = &wait;
-		bio->bi_end_io = rrpc_end_sync_bio;
-
-		bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
-
-		/* turn the command around and write the data back to a new
-		 * address
-		 */
-		if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
-			pr_err("rrpc: gc write failed.\n");
-			rrpc_inflight_laddr_release(rrpc, rqd);
-			goto finished;
-		}
-		wait_for_completion_io(&wait);
-
-		rrpc_inflight_laddr_release(rrpc, rqd);
-		if (bio->bi_status)
-			goto finished;
-
-		bio_reset(bio);
-	}
-
-finished:
-	mempool_free(page, rrpc->page_pool);
-	bio_put(bio);
-
-	if (!bitmap_full(rblk->invalid_pages, nr_sec_per_blk)) {
-		pr_err("nvm: failed to garbage collect block\n");
-		return -EIO;
-	}
-
-	return 0;
-}
-
-static void rrpc_block_gc(struct work_struct *work)
-{
-	struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
-									ws_gc);
-	struct rrpc *rrpc = gcb->rrpc;
-	struct rrpc_block *rblk = gcb->rblk;
-	struct rrpc_lun *rlun = rblk->rlun;
-	struct ppa_addr ppa;
-
-	mempool_free(gcb, rrpc->gcb_pool);
-	pr_debug("nvm: block 'ch:%d,lun:%d,blk:%d' being reclaimed\n",
-			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->bppa.g.ch;
-	ppa.g.lun = rlun->bppa.g.lun;
-	ppa.g.blk = rblk->id;
-
-	if (nvm_erase_sync(rrpc->dev, &ppa, 1))
-		goto put_back;
-
-	rrpc_put_blk(rrpc, rblk);
-
-	return;
-
-put_back:
-	spin_lock(&rlun->lock);
-	list_add_tail(&rblk->prio, &rlun->prio_list);
-	spin_unlock(&rlun->lock);
-}
-
-/* the block with highest number of invalid pages, will be in the beginning
- * of the list
- */
-static struct rrpc_block *rblk_max_invalid(struct rrpc_block *ra,
-							struct rrpc_block *rb)
-{
-	if (ra->nr_invalid_pages == rb->nr_invalid_pages)
-		return ra;
-
-	return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
-}
-
-/* linearly find the block with highest number of invalid pages
- * requires lun->lock
- */
-static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
-{
-	struct list_head *prio_list = &rlun->prio_list;
-	struct rrpc_block *rblk, *max;
-
-	BUG_ON(list_empty(prio_list));
-
-	max = list_first_entry(prio_list, struct rrpc_block, prio);
-	list_for_each_entry(rblk, prio_list, prio)
-		max = rblk_max_invalid(max, rblk);
-
-	return max;
-}
-
-static void rrpc_lun_gc(struct work_struct *work)
-{
-	struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
-	struct rrpc *rrpc = rlun->rrpc;
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_block_gc *gcb;
-	unsigned int nr_blocks_need;
-
-	nr_blocks_need = dev->geo.blks_per_lun / GC_LIMIT_INVERSE;
-
-	if (nr_blocks_need < rrpc->nr_luns)
-		nr_blocks_need = rrpc->nr_luns;
-
-	spin_lock(&rlun->lock);
-	while (nr_blocks_need > rlun->nr_free_blocks &&
-					!list_empty(&rlun->prio_list)) {
-		struct rrpc_block *rblk = block_prio_find_max(rlun);
-
-		if (!rblk->nr_invalid_pages)
-			break;
-
-		gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
-		if (!gcb)
-			break;
-
-		list_del_init(&rblk->prio);
-
-		WARN_ON(!block_is_full(rrpc, rblk));
-
-		pr_debug("rrpc: selected block 'ch:%d,lun:%d,blk:%d' for GC\n",
-					rlun->bppa.g.ch, rlun->bppa.g.lun,
-					rblk->id);
-
-		gcb->rrpc = rrpc;
-		gcb->rblk = rblk;
-		INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
-
-		queue_work(rrpc->kgc_wq, &gcb->ws_gc);
-
-		nr_blocks_need--;
-	}
-	spin_unlock(&rlun->lock);
-
-	/* TODO: Hint that request queue can be started again */
-}
-
-static void rrpc_gc_queue(struct work_struct *work)
-{
-	struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
-									ws_gc);
-	struct rrpc *rrpc = gcb->rrpc;
-	struct rrpc_block *rblk = gcb->rblk;
-	struct rrpc_lun *rlun = rblk->rlun;
-
-	spin_lock(&rlun->lock);
-	list_add_tail(&rblk->prio, &rlun->prio_list);
-	spin_unlock(&rlun->lock);
-
-	mempool_free(gcb, rrpc->gcb_pool);
-	pr_debug("nvm: block 'ch:%d,lun:%d,blk:%d' full, allow GC (sched)\n",
-					rlun->bppa.g.ch, rlun->bppa.g.lun,
-					rblk->id);
-}
-
-static const struct block_device_operations rrpc_fops = {
-	.owner		= THIS_MODULE,
-};
-
-static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc)
-{
-	unsigned int i;
-	struct rrpc_lun *rlun, *max_free;
-
-	if (!is_gc)
-		return get_next_lun(rrpc);
-
-	/* during GC, we don't care about RR, instead we want to make
-	 * sure that we maintain evenness between the block luns.
-	 */
-	max_free = &rrpc->luns[0];
-	/* prevent GC-ing lun from devouring pages of a lun with
-	 * little free blocks. We don't take the lock as we only need an
-	 * estimate.
-	 */
-	rrpc_for_each_lun(rrpc, rlun, i) {
-		if (rlun->nr_free_blocks > max_free->nr_free_blocks)
-			max_free = rlun;
-	}
-
-	return max_free;
-}
-
-static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
-					struct rrpc_block *rblk, u64 paddr)
-{
-	struct rrpc_addr *gp;
-	struct rrpc_rev_addr *rev;
-
-	BUG_ON(laddr >= rrpc->nr_sects);
-
-	gp = &rrpc->trans_map[laddr];
-	spin_lock(&rrpc->rev_lock);
-	if (gp->rblk)
-		rrpc_page_invalidate(rrpc, gp);
-
-	gp->addr = paddr;
-	gp->rblk = rblk;
-
-	rev = &rrpc->rev_trans_map[gp->addr];
-	rev->addr = laddr;
-	spin_unlock(&rrpc->rev_lock);
-
-	return gp;
-}
-
-static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
-{
-	u64 addr = ADDR_EMPTY;
-
-	spin_lock(&rblk->lock);
-	if (block_is_full(rrpc, rblk))
-		goto out;
-
-	addr = rblk->next_page;
-
-	rblk->next_page++;
-out:
-	spin_unlock(&rblk->lock);
-	return addr;
-}
-
-/* Map logical address to a physical page. The mapping implements a round robin
- * approach and allocates a page from the next lun available.
- *
- * Returns rrpc_addr with the physical address and block. Returns NULL if no
- * blocks in the next rlun are available.
- */
-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 ppa;
-
-	/*
-	 * page allocation steps:
-	 * 1. Try to allocate new page from current rblk
-	 * 2a. If succeed, proceed to map it in and return
-	 * 2b. If fail, first try to allocate a new block from media manger,
-	 *     and then retry step 1. Retry until the normal block pool is
-	 *     exhausted.
-	 * 3. If exhausted, and garbage collector is requesting the block,
-	 *    go to the reserved block and retry step 1.
-	 *    In the case that this fails as well, or it is not GC
-	 *    requesting, report not able to retrieve a block and let the
-	 *    caller handle further processing.
-	 */
-
-	spin_lock(&rlun->lock);
-	cur_rblk = &rlun->cur;
-	rblk = rlun->cur;
-retry:
-	paddr = rrpc_alloc_addr(rrpc, rblk);
-
-	if (paddr != ADDR_EMPTY)
-		goto done;
-
-	if (!list_empty(&rlun->wblk_list)) {
-new_blk:
-		rblk = list_first_entry(&rlun->wblk_list, struct rrpc_block,
-									prio);
-		rrpc_set_lun_cur(rlun, rblk, cur_rblk);
-		list_del(&rblk->prio);
-		goto retry;
-	}
-	spin_unlock(&rlun->lock);
-
-	rblk = rrpc_get_blk(rrpc, rlun, gc_force);
-	if (rblk) {
-		spin_lock(&rlun->lock);
-		list_add_tail(&rblk->prio, &rlun->wblk_list);
-		/*
-		 * another thread might already have added a new block,
-		 * Therefore, make sure that one is used, instead of the
-		 * one just added.
-		 */
-		goto new_blk;
-	}
-
-	if (unlikely(is_gc) && !gc_force) {
-		/* retry from emergency gc block */
-		cur_rblk = &rlun->gc_cur;
-		rblk = rlun->gc_cur;
-		gc_force = 1;
-		spin_lock(&rlun->lock);
-		goto retry;
-	}
-
-	pr_err("rrpc: failed to allocate new block\n");
-	return ppa;
-done:
-	spin_unlock(&rlun->lock);
-	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)
-{
-	struct rrpc_block_gc *gcb;
-
-	gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
-	if (!gcb) {
-		pr_err("rrpc: unable to queue block for gc.");
-		return;
-	}
-
-	gcb->rrpc = rrpc;
-	gcb->rblk = rblk;
-
-	INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
-	queue_work(rrpc->kgc_wq, &gcb->ws_gc);
-}
-
-static struct rrpc_lun *rrpc_ppa_to_lun(struct rrpc *rrpc, struct ppa_addr p)
-{
-	struct rrpc_lun *rlun = NULL;
-	int i;
-
-	for (i = 0; i < rrpc->nr_luns; i++) {
-		if (rrpc->luns[i].bppa.g.ch == p.g.ch &&
-				rrpc->luns[i].bppa.g.lun == p.g.lun) {
-			rlun = &rrpc->luns[i];
-			break;
-		}
-	}
-
-	return rlun;
-}
-
-static void __rrpc_mark_bad_block(struct rrpc *rrpc, struct ppa_addr ppa)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_lun *rlun;
-	struct rrpc_block *rblk;
-
-	rlun = rrpc_ppa_to_lun(rrpc, ppa);
-	rblk = &rlun->blocks[ppa.g.blk];
-	rblk->state = NVM_BLK_ST_BAD;
-
-	nvm_set_tgt_bb_tbl(dev, &ppa, 1, NVM_BLK_T_GRWN_BAD);
-}
-
-static void rrpc_mark_bad_block(struct rrpc *rrpc, struct nvm_rq *rqd)
-{
-	void *comp_bits = &rqd->ppa_status;
-	struct ppa_addr ppa, prev_ppa;
-	int nr_ppas = rqd->nr_ppas;
-	int bit;
-
-	if (rqd->nr_ppas == 1)
-		__rrpc_mark_bad_block(rrpc, rqd->ppa_addr);
-
-	ppa_set_empty(&prev_ppa);
-	bit = -1;
-	while ((bit = find_next_bit(comp_bits, nr_ppas, bit + 1)) < nr_ppas) {
-		ppa = rqd->ppa_list[bit];
-		if (ppa_cmp_blk(ppa, prev_ppa))
-			continue;
-
-		__rrpc_mark_bad_block(rrpc, ppa);
-	}
-}
-
-static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
-						sector_t laddr, uint8_t npages)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_addr *p;
-	struct rrpc_block *rblk;
-	int cmnt_size, i;
-
-	for (i = 0; i < npages; i++) {
-		p = &rrpc->trans_map[laddr + i];
-		rblk = p->rblk;
-
-		cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
-		if (unlikely(cmnt_size == dev->geo.sec_per_blk))
-			rrpc_run_gc(rrpc, rblk);
-	}
-}
-
-static void rrpc_end_io(struct nvm_rq *rqd)
-{
-	struct rrpc *rrpc = rqd->private;
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
-	uint8_t npages = rqd->nr_ppas;
-	sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
-
-	if (bio_data_dir(rqd->bio) == WRITE) {
-		if (rqd->error == NVM_RSP_ERR_FAILWRITE)
-			rrpc_mark_bad_block(rrpc, rqd);
-
-		rrpc_end_io_write(rrpc, rrqd, laddr, npages);
-	}
-
-	bio_put(rqd->bio);
-
-	if (rrqd->flags & NVM_IOTYPE_GC)
-		return;
-
-	rrpc_unlock_rq(rrpc, rqd);
-
-	if (npages > 1)
-		nvm_dev_dma_free(dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
-
-	mempool_free(rqd, rrpc->rq_pool);
-}
-
-static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
-			struct nvm_rq *rqd, unsigned long flags, int npages)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
-	struct rrpc_addr *gp;
-	sector_t laddr = rrpc_get_laddr(bio);
-	int is_gc = flags & NVM_IOTYPE_GC;
-	int i;
-
-	if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
-		nvm_dev_dma_free(dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
-		return NVM_IO_REQUEUE;
-	}
-
-	for (i = 0; i < npages; i++) {
-		/* We assume that mapping occurs at 4KB granularity */
-		BUG_ON(!(laddr + i < rrpc->nr_sects));
-		gp = &rrpc->trans_map[laddr + i];
-
-		if (gp->rblk) {
-			rqd->ppa_list[i] = rrpc_ppa_to_gaddr(dev, gp);
-		} else {
-			BUG_ON(is_gc);
-			rrpc_unlock_laddr(rrpc, r);
-			nvm_dev_dma_free(dev->parent, rqd->ppa_list,
-							rqd->dma_ppa_list);
-			return NVM_IO_DONE;
-		}
-	}
-
-	rqd->opcode = NVM_OP_HBREAD;
-
-	return NVM_IO_OK;
-}
-
-static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
-							unsigned long flags)
-{
-	int is_gc = flags & NVM_IOTYPE_GC;
-	sector_t laddr = rrpc_get_laddr(bio);
-	struct rrpc_addr *gp;
-
-	if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
-		return NVM_IO_REQUEUE;
-
-	BUG_ON(!(laddr < rrpc->nr_sects));
-	gp = &rrpc->trans_map[laddr];
-
-	if (gp->rblk) {
-		rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp);
-	} else {
-		BUG_ON(is_gc);
-		rrpc_unlock_rq(rrpc, rqd);
-		return NVM_IO_DONE;
-	}
-
-	rqd->opcode = NVM_OP_HBREAD;
-
-	return NVM_IO_OK;
-}
-
-static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
-			struct nvm_rq *rqd, unsigned long flags, int npages)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
-	struct ppa_addr p;
-	sector_t laddr = rrpc_get_laddr(bio);
-	int is_gc = flags & NVM_IOTYPE_GC;
-	int i;
-
-	if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
-		nvm_dev_dma_free(dev->parent, rqd->ppa_list, rqd->dma_ppa_list);
-		return NVM_IO_REQUEUE;
-	}
-
-	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.ppa == ADDR_EMPTY) {
-			BUG_ON(is_gc);
-			rrpc_unlock_laddr(rrpc, r);
-			nvm_dev_dma_free(dev->parent, rqd->ppa_list,
-							rqd->dma_ppa_list);
-			rrpc_gc_kick(rrpc);
-			return NVM_IO_REQUEUE;
-		}
-
-		rqd->ppa_list[i] = p;
-	}
-
-	rqd->opcode = NVM_OP_HBWRITE;
-
-	return NVM_IO_OK;
-}
-
-static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
-				struct nvm_rq *rqd, unsigned long flags)
-{
-	struct ppa_addr p;
-	int is_gc = flags & NVM_IOTYPE_GC;
-	sector_t laddr = rrpc_get_laddr(bio);
-
-	if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
-		return NVM_IO_REQUEUE;
-
-	p = rrpc_map_page(rrpc, laddr, is_gc);
-	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 = p;
-	rqd->opcode = NVM_OP_HBWRITE;
-
-	return NVM_IO_OK;
-}
-
-static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
-			struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-
-	if (npages > 1) {
-		rqd->ppa_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
-							&rqd->dma_ppa_list);
-		if (!rqd->ppa_list) {
-			pr_err("rrpc: not able to allocate ppa list\n");
-			return NVM_IO_ERR;
-		}
-
-		if (bio_op(bio) == REQ_OP_WRITE)
-			return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
-									npages);
-
-		return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
-	}
-
-	if (bio_op(bio) == REQ_OP_WRITE)
-		return rrpc_write_rq(rrpc, bio, rqd, flags);
-
-	return rrpc_read_rq(rrpc, bio, rqd, flags);
-}
-
-static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
-				struct nvm_rq *rqd, unsigned long flags)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
-	uint8_t nr_pages = rrpc_get_pages(bio);
-	int bio_size = bio_sectors(bio) << 9;
-	int err;
-
-	if (bio_size < dev->geo.sec_size)
-		return NVM_IO_ERR;
-	else if (bio_size > dev->geo.max_rq_size)
-		return NVM_IO_ERR;
-
-	err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
-	if (err)
-		return err;
-
-	bio_get(bio);
-	rqd->bio = bio;
-	rqd->private = rrpc;
-	rqd->nr_ppas = nr_pages;
-	rqd->end_io = rrpc_end_io;
-	rrq->flags = flags;
-
-	err = nvm_submit_io(dev, rqd);
-	if (err) {
-		pr_err("rrpc: I/O submission failed: %d\n", err);
-		bio_put(bio);
-		if (!(flags & NVM_IOTYPE_GC)) {
-			rrpc_unlock_rq(rrpc, rqd);
-			if (rqd->nr_ppas > 1)
-				nvm_dev_dma_free(dev->parent, rqd->ppa_list,
-							rqd->dma_ppa_list);
-		}
-		return NVM_IO_ERR;
-	}
-
-	return NVM_IO_OK;
-}
-
-static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio)
-{
-	struct rrpc *rrpc = q->queuedata;
-	struct nvm_rq *rqd;
-	int err;
-
-	blk_queue_split(q, &bio);
-
-	if (bio_op(bio) == REQ_OP_DISCARD) {
-		rrpc_discard(rrpc, bio);
-		return BLK_QC_T_NONE;
-	}
-
-	rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
-	memset(rqd, 0, sizeof(struct nvm_rq));
-
-	err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
-	switch (err) {
-	case NVM_IO_OK:
-		return BLK_QC_T_NONE;
-	case NVM_IO_ERR:
-		bio_io_error(bio);
-		break;
-	case NVM_IO_DONE:
-		bio_endio(bio);
-		break;
-	case NVM_IO_REQUEUE:
-		spin_lock(&rrpc->bio_lock);
-		bio_list_add(&rrpc->requeue_bios, bio);
-		spin_unlock(&rrpc->bio_lock);
-		queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
-		break;
-	}
-
-	mempool_free(rqd, rrpc->rq_pool);
-	return BLK_QC_T_NONE;
-}
-
-static void rrpc_requeue(struct work_struct *work)
-{
-	struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
-	struct bio_list bios;
-	struct bio *bio;
-
-	bio_list_init(&bios);
-
-	spin_lock(&rrpc->bio_lock);
-	bio_list_merge(&bios, &rrpc->requeue_bios);
-	bio_list_init(&rrpc->requeue_bios);
-	spin_unlock(&rrpc->bio_lock);
-
-	while ((bio = bio_list_pop(&bios)))
-		rrpc_make_rq(rrpc->disk->queue, bio);
-}
-
-static void rrpc_gc_free(struct rrpc *rrpc)
-{
-	if (rrpc->krqd_wq)
-		destroy_workqueue(rrpc->krqd_wq);
-
-	if (rrpc->kgc_wq)
-		destroy_workqueue(rrpc->kgc_wq);
-}
-
-static int rrpc_gc_init(struct rrpc *rrpc)
-{
-	rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
-								rrpc->nr_luns);
-	if (!rrpc->krqd_wq)
-		return -ENOMEM;
-
-	rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
-	if (!rrpc->kgc_wq)
-		return -ENOMEM;
-
-	timer_setup(&rrpc->gc_timer, rrpc_gc_timer, 0);
-
-	return 0;
-}
-
-static void rrpc_map_free(struct rrpc *rrpc)
-{
-	vfree(rrpc->rev_trans_map);
-	vfree(rrpc->trans_map);
-}
-
-static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
-{
-	struct rrpc *rrpc = (struct rrpc *)private;
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_addr *addr = rrpc->trans_map + slba;
-	struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
-	struct rrpc_lun *rlun;
-	struct rrpc_block *rblk;
-	u64 i;
-
-	for (i = 0; i < nlb; i++) {
-		struct ppa_addr gaddr;
-		u64 pba = le64_to_cpu(entries[i]);
-		unsigned int mod;
-
-		/* LNVM treats address-spaces as silos, LBA and PBA are
-		 * equally large and zero-indexed.
-		 */
-		if (unlikely(pba >= dev->total_secs && pba != U64_MAX)) {
-			pr_err("nvm: L2P data entry is out of bounds!\n");
-			pr_err("nvm: Maybe loaded an old target L2P\n");
-			return -EINVAL;
-		}
-
-		/* Address zero is a special one. The first page on a disk is
-		 * protected. As it often holds internal device boot
-		 * information.
-		 */
-		if (!pba)
-			continue;
-
-		div_u64_rem(pba, rrpc->nr_sects, &mod);
-
-		gaddr = rrpc_recov_addr(dev, pba);
-		rlun = rrpc_ppa_to_lun(rrpc, gaddr);
-		if (!rlun) {
-			pr_err("rrpc: l2p corruption on lba %llu\n",
-							slba + i);
-			return -EINVAL;
-		}
-
-		rblk = &rlun->blocks[gaddr.g.blk];
-		if (!rblk->state) {
-			/* at this point, we don't know anything about the
-			 * block. It's up to the FTL on top to re-etablish the
-			 * block state. The block is assumed to be open.
-			 */
-			list_move_tail(&rblk->list, &rlun->used_list);
-			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;
-}
-
-static int rrpc_map_init(struct rrpc *rrpc)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	sector_t i;
-	int ret;
-
-	rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_sects);
-	if (!rrpc->trans_map)
-		return -ENOMEM;
-
-	rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
-							* rrpc->nr_sects);
-	if (!rrpc->rev_trans_map)
-		return -ENOMEM;
-
-	for (i = 0; i < rrpc->nr_sects; i++) {
-		struct rrpc_addr *p = &rrpc->trans_map[i];
-		struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
-
-		p->addr = ADDR_EMPTY;
-		r->addr = ADDR_EMPTY;
-	}
-
-	/* Bring up the mapping table from device */
-	ret = nvm_get_l2p_tbl(dev, rrpc->soffset, rrpc->nr_sects,
-							rrpc_l2p_update, rrpc);
-	if (ret) {
-		pr_err("nvm: rrpc: could not read L2P table.\n");
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-/* Minimum pages needed within a lun */
-#define PAGE_POOL_SIZE 16
-#define ADDR_POOL_SIZE 64
-
-static int rrpc_core_init(struct rrpc *rrpc)
-{
-	down_write(&rrpc_lock);
-	if (!rrpc_gcb_cache) {
-		rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
-				sizeof(struct rrpc_block_gc), 0, 0, NULL);
-		if (!rrpc_gcb_cache) {
-			up_write(&rrpc_lock);
-			return -ENOMEM;
-		}
-
-		rrpc_rq_cache = kmem_cache_create("rrpc_rq",
-				sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
-				0, 0, NULL);
-		if (!rrpc_rq_cache) {
-			kmem_cache_destroy(rrpc_gcb_cache);
-			up_write(&rrpc_lock);
-			return -ENOMEM;
-		}
-	}
-	up_write(&rrpc_lock);
-
-	rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
-	if (!rrpc->page_pool)
-		return -ENOMEM;
-
-	rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->geo.nr_luns,
-								rrpc_gcb_cache);
-	if (!rrpc->gcb_pool)
-		return -ENOMEM;
-
-	rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
-	if (!rrpc->rq_pool)
-		return -ENOMEM;
-
-	spin_lock_init(&rrpc->inflights.lock);
-	INIT_LIST_HEAD(&rrpc->inflights.reqs);
-
-	return 0;
-}
-
-static void rrpc_core_free(struct rrpc *rrpc)
-{
-	mempool_destroy(rrpc->page_pool);
-	mempool_destroy(rrpc->gcb_pool);
-	mempool_destroy(rrpc->rq_pool);
-}
-
-static void rrpc_luns_free(struct rrpc *rrpc)
-{
-	struct rrpc_lun *rlun;
-	int i;
-
-	if (!rrpc->luns)
-		return;
-
-	for (i = 0; i < rrpc->nr_luns; i++) {
-		rlun = &rrpc->luns[i];
-		vfree(rlun->blocks);
-	}
-
-	kfree(rrpc->luns);
-}
-
-static int rrpc_bb_discovery(struct nvm_tgt_dev *dev, struct rrpc_lun *rlun)
-{
-	struct nvm_geo *geo = &dev->geo;
-	struct rrpc_block *rblk;
-	struct ppa_addr ppa;
-	u8 *blks;
-	int nr_blks;
-	int i;
-	int ret;
-
-	if (!dev->parent->ops->get_bb_tbl)
-		return 0;
-
-	nr_blks = geo->blks_per_lun * geo->plane_mode;
-	blks = kmalloc(nr_blks, GFP_KERNEL);
-	if (!blks)
-		return -ENOMEM;
-
-	ppa.ppa = 0;
-	ppa.g.ch = rlun->bppa.g.ch;
-	ppa.g.lun = rlun->bppa.g.lun;
-
-	ret = nvm_get_tgt_bb_tbl(dev, ppa, blks);
-	if (ret) {
-		pr_err("rrpc: could not get BB table\n");
-		goto out;
-	}
-
-	nr_blks = nvm_bb_tbl_fold(dev->parent, blks, nr_blks);
-	if (nr_blks < 0) {
-		ret = nr_blks;
-		goto out;
-	}
-
-	for (i = 0; i < nr_blks; i++) {
-		if (blks[i] == NVM_BLK_T_FREE)
-			continue;
-
-		rblk = &rlun->blocks[i];
-		list_move_tail(&rblk->list, &rlun->bb_list);
-		rblk->state = NVM_BLK_ST_BAD;
-		rlun->nr_free_blocks--;
-	}
-
-out:
-	kfree(blks);
-	return ret;
-}
-
-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 rrpc_lun *rlun;
-	int i, j, ret = -EINVAL;
-
-	if (geo->sec_per_blk > MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
-		pr_err("rrpc: number of pages per block too high.");
-		return -EINVAL;
-	}
-
-	spin_lock_init(&rrpc->rev_lock);
-
-	rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
-								GFP_KERNEL);
-	if (!rrpc->luns)
-		return -ENOMEM;
-
-	/* 1:1 mapping */
-	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) {
-			ret = -ENOMEM;
-			goto err;
-		}
-
-		INIT_LIST_HEAD(&rlun->free_list);
-		INIT_LIST_HEAD(&rlun->used_list);
-		INIT_LIST_HEAD(&rlun->bb_list);
-
-		for (j = 0; j < geo->blks_per_lun; j++) {
-			struct rrpc_block *rblk = &rlun->blocks[j];
-
-			rblk->id = j;
-			rblk->rlun = rlun;
-			rblk->state = NVM_BLK_T_FREE;
-			INIT_LIST_HEAD(&rblk->prio);
-			INIT_LIST_HEAD(&rblk->list);
-			spin_lock_init(&rblk->lock);
-
-			list_add_tail(&rblk->list, &rlun->free_list);
-		}
-
-		rlun->rrpc = rrpc;
-		rlun->nr_free_blocks = geo->blks_per_lun;
-		rlun->reserved_blocks = 2; /* for GC only */
-
-		INIT_LIST_HEAD(&rlun->prio_list);
-		INIT_LIST_HEAD(&rlun->wblk_list);
-
-		INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
-		spin_lock_init(&rlun->lock);
-
-		if (rrpc_bb_discovery(dev, rlun))
-			goto err;
-
-	}
-
-	return 0;
-err:
-	return ret;
-}
-
-/* returns 0 on success and stores the beginning address in *begin */
-static int rrpc_area_init(struct rrpc *rrpc, sector_t *begin)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	sector_t size = rrpc->nr_sects * dev->geo.sec_size;
-	int ret;
-
-	size >>= 9;
-
-	ret = nvm_get_area(dev, begin, size);
-	if (!ret)
-		*begin >>= (ilog2(dev->geo.sec_size) - 9);
-
-	return ret;
-}
-
-static void rrpc_area_free(struct rrpc *rrpc)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	sector_t begin = rrpc->soffset << (ilog2(dev->geo.sec_size) - 9);
-
-	nvm_put_area(dev, begin);
-}
-
-static void rrpc_free(struct rrpc *rrpc)
-{
-	rrpc_gc_free(rrpc);
-	rrpc_map_free(rrpc);
-	rrpc_core_free(rrpc);
-	rrpc_luns_free(rrpc);
-	rrpc_area_free(rrpc);
-
-	kfree(rrpc);
-}
-
-static void rrpc_exit(void *private)
-{
-	struct rrpc *rrpc = private;
-
-	del_timer(&rrpc->gc_timer);
-
-	flush_workqueue(rrpc->krqd_wq);
-	flush_workqueue(rrpc->kgc_wq);
-
-	rrpc_free(rrpc);
-}
-
-static sector_t rrpc_capacity(void *private)
-{
-	struct rrpc *rrpc = private;
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	sector_t reserved, provisioned;
-
-	/* cur, gc, and two emergency blocks for each lun */
-	reserved = rrpc->nr_luns * dev->geo.sec_per_blk * 4;
-	provisioned = rrpc->nr_sects - reserved;
-
-	if (reserved > rrpc->nr_sects) {
-		pr_err("rrpc: not enough space available to expose storage.\n");
-		return 0;
-	}
-
-	sector_div(provisioned, 10);
-	return provisioned * 9 * NR_PHY_IN_LOG;
-}
-
-/*
- * Looks up the logical address from reverse trans map and check if its valid by
- * comparing the logical to physical address with the physical address.
- * Returns 0 on free, otherwise 1 if in use
- */
-static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	int offset;
-	struct rrpc_addr *laddr;
-	u64 bpaddr, paddr, pladdr;
-
-	bpaddr = block_to_rel_addr(rrpc, rblk);
-	for (offset = 0; offset < dev->geo.sec_per_blk; offset++) {
-		paddr = bpaddr + offset;
-
-		pladdr = rrpc->rev_trans_map[paddr].addr;
-		if (pladdr == ADDR_EMPTY)
-			continue;
-
-		laddr = &rrpc->trans_map[pladdr];
-
-		if (paddr == laddr->addr) {
-			laddr->rblk = rblk;
-		} else {
-			set_bit(offset, rblk->invalid_pages);
-			rblk->nr_invalid_pages++;
-		}
-	}
-}
-
-static int rrpc_blocks_init(struct rrpc *rrpc)
-{
-	struct nvm_tgt_dev *dev = rrpc->dev;
-	struct rrpc_lun *rlun;
-	struct rrpc_block *rblk;
-	int lun_iter, blk_iter;
-
-	for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
-		rlun = &rrpc->luns[lun_iter];
-
-		for (blk_iter = 0; blk_iter < dev->geo.blks_per_lun;
-								blk_iter++) {
-			rblk = &rlun->blocks[blk_iter];
-			rrpc_block_map_update(rrpc, rblk);
-		}
-	}
-
-	return 0;
-}
-
-static int rrpc_luns_configure(struct rrpc *rrpc)
-{
-	struct rrpc_lun *rlun;
-	struct rrpc_block *rblk;
-	int i;
-
-	for (i = 0; i < rrpc->nr_luns; i++) {
-		rlun = &rrpc->luns[i];
-
-		rblk = rrpc_get_blk(rrpc, rlun, 0);
-		if (!rblk)
-			goto err;
-		rrpc_set_lun_cur(rlun, rblk, &rlun->cur);
-
-		/* Emergency gc block */
-		rblk = rrpc_get_blk(rrpc, rlun, 1);
-		if (!rblk)
-			goto err;
-		rrpc_set_lun_cur(rlun, rblk, &rlun->gc_cur);
-	}
-
-	return 0;
-err:
-	rrpc_put_blks(rrpc);
-	return -EINVAL;
-}
-
-static struct nvm_tgt_type tt_rrpc;
-
-static void *rrpc_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
-		       int flags)
-{
-	struct request_queue *bqueue = dev->q;
-	struct request_queue *tqueue = tdisk->queue;
-	struct nvm_geo *geo = &dev->geo;
-	struct rrpc *rrpc;
-	sector_t soffset;
-	int ret;
-
-	if (!(dev->identity.dom & NVM_RSP_L2P)) {
-		pr_err("nvm: rrpc: device does not support l2p (%x)\n",
-							dev->identity.dom);
-		return ERR_PTR(-EINVAL);
-	}
-
-	rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
-	if (!rrpc)
-		return ERR_PTR(-ENOMEM);
-
-	rrpc->dev = dev;
-	rrpc->disk = tdisk;
-
-	bio_list_init(&rrpc->requeue_bios);
-	spin_lock_init(&rrpc->bio_lock);
-	INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
-
-	rrpc->nr_luns = geo->nr_luns;
-	rrpc->nr_sects = (unsigned long long)geo->sec_per_lun * rrpc->nr_luns;
-
-	/* simple round-robin strategy */
-	atomic_set(&rrpc->next_lun, -1);
-
-	ret = rrpc_area_init(rrpc, &soffset);
-	if (ret < 0) {
-		pr_err("nvm: rrpc: could not initialize area\n");
-		return ERR_PTR(ret);
-	}
-	rrpc->soffset = soffset;
-
-	ret = rrpc_luns_init(rrpc, dev->luns);
-	if (ret) {
-		pr_err("nvm: rrpc: could not initialize luns\n");
-		goto err;
-	}
-
-	ret = rrpc_core_init(rrpc);
-	if (ret) {
-		pr_err("nvm: rrpc: could not initialize core\n");
-		goto err;
-	}
-
-	ret = rrpc_map_init(rrpc);
-	if (ret) {
-		pr_err("nvm: rrpc: could not initialize maps\n");
-		goto err;
-	}
-
-	ret = rrpc_blocks_init(rrpc);
-	if (ret) {
-		pr_err("nvm: rrpc: could not initialize state for blocks\n");
-		goto err;
-	}
-
-	ret = rrpc_luns_configure(rrpc);
-	if (ret) {
-		pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
-		goto err;
-	}
-
-	ret = rrpc_gc_init(rrpc);
-	if (ret) {
-		pr_err("nvm: rrpc: could not initialize gc\n");
-		goto err;
-	}
-
-	/* inherit the size from the underlying device */
-	blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
-	blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
-
-	pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
-			rrpc->nr_luns, (unsigned long long)rrpc->nr_sects);
-
-	mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
-
-	return rrpc;
-err:
-	rrpc_free(rrpc);
-	return ERR_PTR(ret);
-}
-
-/* round robin, page-based FTL, and cost-based GC */
-static struct nvm_tgt_type tt_rrpc = {
-	.name		= "rrpc",
-	.version	= {1, 0, 0},
-
-	.make_rq	= rrpc_make_rq,
-	.capacity	= rrpc_capacity,
-
-	.init		= rrpc_init,
-	.exit		= rrpc_exit,
-};
-
-static int __init rrpc_module_init(void)
-{
-	return nvm_register_tgt_type(&tt_rrpc);
-}
-
-static void rrpc_module_exit(void)
-{
-	nvm_unregister_tgt_type(&tt_rrpc);
-}
-
-module_init(rrpc_module_init);
-module_exit(rrpc_module_exit);
-MODULE_LICENSE("GPL v2");
-MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");

drivers/lightnvm/rrpc.h

···
-/*
- * Copyright (C) 2015 IT University of Copenhagen
- * Initial release: Matias Bjorling <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs.
- */
-
-#ifndef RRPC_H_
-#define RRPC_H_
-
-#include <linux/blkdev.h>
-#include <linux/blk-mq.h>
-#include <linux/bio.h>
-#include <linux/module.h>
-#include <linux/kthread.h>
-#include <linux/vmalloc.h>
-
-#include <linux/lightnvm.h>
-
-/* Run only GC if less than 1/X blocks are free */
-#define GC_LIMIT_INVERSE 10
-#define GC_TIME_SECS 100
-
-#define RRPC_SECTOR (512)
-#define RRPC_EXPOSED_PAGE_SIZE (4096)
-
-#define NR_PHY_IN_LOG (RRPC_EXPOSED_PAGE_SIZE / RRPC_SECTOR)
-
-struct rrpc_inflight {
-	struct list_head reqs;
-	spinlock_t lock;
-};
-
-struct rrpc_inflight_rq {
-	struct list_head list;
-	sector_t l_start;
-	sector_t l_end;
-};
-
-struct rrpc_rq {
-	struct rrpc_inflight_rq inflight_rq;
-	unsigned long flags;
-};
-
-struct rrpc_block {
-	int id;				/* id inside of LUN */
-	struct rrpc_lun *rlun;
-
-	struct list_head prio;		/* LUN CG list */
-	struct list_head list;		/* LUN free, used, bb list */
-
-#define MAX_INVALID_PAGES_STORAGE 8
-	/* Bitmap for invalid page intries */
-	unsigned long invalid_pages[MAX_INVALID_PAGES_STORAGE];
-	/* points to the next writable page within a block */
-	unsigned int next_page;
-	/* number of pages that are invalid, wrt host page size */
-	unsigned int nr_invalid_pages;
-
-	int state;
-
-	spinlock_t lock;
-	atomic_t data_cmnt_size; /* data pages committed to stable storage */
-};
-
-struct rrpc_lun {
-	struct rrpc *rrpc;
-
-	int id;
-	struct ppa_addr bppa;
-
-	struct rrpc_block *cur, *gc_cur;
-	struct rrpc_block *blocks;	/* Reference to block allocation */
-
-	struct list_head prio_list;	/* Blocks that may be GC'ed */
-	struct list_head wblk_list;	/* Queued blocks to be written to */
-
-	/* lun block lists */
-	struct list_head used_list;	/* In-use blocks */
-	struct list_head free_list;	/* Not used blocks i.e. released
-					 * and ready for use
-					 */
-	struct list_head bb_list;	/* Bad blocks. Mutually exclusive with
-					 * free_list and used_list
-					 */
-	unsigned int nr_free_blocks;	/* Number of unused blocks */
-
-	struct work_struct ws_gc;
-
-	int reserved_blocks;
-
-	spinlock_t lock;
-};
-
-struct rrpc {
-	struct nvm_tgt_dev *dev;
-	struct gendisk *disk;
-
-	sector_t soffset; /* logical sector offset */
-
-	int nr_luns;
-	struct rrpc_lun *luns;
-
-	/* calculated values */
-	unsigned long long nr_sects;
-
-	/* Write strategy variables. Move these into each for structure for each
-	 * strategy
-	 */
-	atomic_t next_lun; /* Whenever a page is written, this is updated
-			    * to point to the next write lun
-			    */
-
-	spinlock_t bio_lock;
-	struct bio_list requeue_bios;
-	struct work_struct ws_requeue;
-
-	/* Simple translation map of logical addresses to physical addresses.
-	 * The logical addresses is known by the host system, while the physical
-	 * addresses are used when writing to the disk block device.
-	 */
-	struct rrpc_addr *trans_map;
-	/* also store a reverse map for garbage collection */
-	struct rrpc_rev_addr *rev_trans_map;
-	spinlock_t rev_lock;
-
-	struct rrpc_inflight inflights;
-
-	mempool_t *addr_pool;
-	mempool_t *page_pool;
-	mempool_t *gcb_pool;
-	mempool_t *rq_pool;
-
-	struct timer_list gc_timer;
-	struct workqueue_struct *krqd_wq;
-	struct workqueue_struct *kgc_wq;
-};
-
-struct rrpc_block_gc {
-	struct rrpc *rrpc;
-	struct rrpc_block *rblk;
-	struct work_struct ws_gc;
-};
-
-/* Logical to physical mapping */
-struct rrpc_addr {
-	u64 addr;
-	struct rrpc_block *rblk;
-};
-
-/* Physical to logical mapping */
-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_tgt_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;
-
-	return (rlun->id * geo->sec_per_lun) + (rblk->id * geo->sec_per_blk);
-}
-
-static inline sector_t rrpc_get_laddr(struct bio *bio)
-{
-	return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
-}
-
-static inline unsigned int rrpc_get_pages(struct bio *bio)
-{
-	return  bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
-}
-
-static inline sector_t rrpc_get_sector(sector_t laddr)
-{
-	return laddr * NR_PHY_IN_LOG;
-}
-
-static inline int request_intersects(struct rrpc_inflight_rq *r,
-				sector_t laddr_start, sector_t laddr_end)
-{
-	return (laddr_end >= r->l_start) && (laddr_start <= r->l_end);
-}
-
-static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
-			     unsigned int pages, struct rrpc_inflight_rq *r)
-{
-	sector_t laddr_end = laddr + pages - 1;
-	struct rrpc_inflight_rq *rtmp;
-
-	WARN_ON(irqs_disabled());
-
-	spin_lock_irq(&rrpc->inflights.lock);
-	list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) {
-		if (unlikely(request_intersects(rtmp, laddr, laddr_end))) {
-			/* existing, overlapping request, come back later */
-			spin_unlock_irq(&rrpc->inflights.lock);
-			return 1;
-		}
-	}
-
-	r->l_start = laddr;
-	r->l_end = laddr_end;
-
-	list_add_tail(&r->list, &rrpc->inflights.reqs);
-	spin_unlock_irq(&rrpc->inflights.lock);
-	return 0;
-}
-
-static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
-				 unsigned int pages,
-				 struct rrpc_inflight_rq *r)
-{
-	BUG_ON((laddr + pages) > rrpc->nr_sects);
-
-	return __rrpc_lock_laddr(rrpc, laddr, pages, r);
-}
-
-static inline struct rrpc_inflight_rq *rrpc_get_inflight_rq(struct nvm_rq *rqd)
-{
-	struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
-
-	return &rrqd->inflight_rq;
-}
-
-static inline int rrpc_lock_rq(struct rrpc *rrpc, struct bio *bio,
-							struct nvm_rq *rqd)
-{
-	sector_t laddr = rrpc_get_laddr(bio);
-	unsigned int pages = rrpc_get_pages(bio);
-	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
-
-	return rrpc_lock_laddr(rrpc, laddr, pages, r);
-}
-
-static inline void rrpc_unlock_laddr(struct rrpc *rrpc,
-						struct rrpc_inflight_rq *r)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&rrpc->inflights.lock, flags);
-	list_del_init(&r->list);
-	spin_unlock_irqrestore(&rrpc->inflights.lock, flags);
-}
-
-static inline void rrpc_unlock_rq(struct rrpc *rrpc, struct nvm_rq *rqd)
-{
-	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
-	uint8_t pages = rqd->nr_ppas;
-
-	BUG_ON((r->l_start + pages) > rrpc->nr_sects);
-
-	rrpc_unlock_laddr(rrpc, r);
-}
-
-#endif /* RRPC_H_ */