[PATCH 0/9] Fixes for LightNVM

[PATCH 0/9] Fixes for LightNVM

[Matias Bjørling]

Hi Jens,

A couple more fixes for LightNVM.

The first three patches are fixed from Tao on rrpc and gennvm. The next
five patches are small fixes and refactoring to prepare for system
blocks. The last patch defaults debugging to not be compiled in and
thereby not expose the parameter configuration interface.

Thanks! Please pick up when convenient.

Matias Bjørling (6):
  lightnvm: check mm before use
  lightnvm: comments on constants
  lightnvm: replace req queue with nvmdev for lld
  lightnvm: fix media mgr registration
  lightnvm: prevent gennvm module unload on use
  lightnvm: do not compile in debugging by default

Wenwei Tao (3):
  lightnvm: use flags in rrpc_get_blk
  lightnvm: put blks when luns configure failed
  lightnvm: refactor spin_unlock in gennvm_get_blk

 drivers/block/null_blk.c     |  9 ++---
 drivers/lightnvm/Kconfig     |  1 +
 drivers/lightnvm/core.c      | 85 ++++++++++++++++++++++----------------------
 drivers/lightnvm/gennvm.c    | 20 ++++++-----
 drivers/lightnvm/rrpc.c      | 25 ++++++++++---
 drivers/nvme/host/lightnvm.c | 26 +++++++-------
 include/linux/lightnvm.h     | 21 +++++++----
 7 files changed, 108 insertions(+), 79 deletions(-)

-- 
2.1.4

[PATCH 1/9] lightnvm: use flags in rrpc_get_blk

[Matias Bjørling]

From: Wenwei Tao <ww.tao0320@gmail.com>

rrpc_get_blk use constant 0 as the input parameter
of nvm_get_blk, this may result in getting gc block
failed unexpectedly.

Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/lightnvm/rrpc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/lightnvm/rrpc.c b/drivers/lightnvm/rrpc.c
index 75e59c3..d606c7a 100644
--- a/drivers/lightnvm/rrpc.c
+++ b/drivers/lightnvm/rrpc.c
@@ -182,7 +182,7 @@ static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
 	struct nvm_block *blk;
 	struct rrpc_block *rblk;
 
-	blk = nvm_get_blk(rrpc->dev, rlun->parent, 0);
+	blk = nvm_get_blk(rrpc->dev, rlun->parent, flags);
 	if (!blk)
 		return NULL;
 
-- 
2.1.4

[PATCH 2/9] lightnvm: put blks when luns configure failed

[Matias Bjørling]

From: Wenwei Tao <ww.tao0320@gmail.com>

Put the allocated blocks back to the free list
when the luns configure failed, to make these
blocks useable to others.

Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/lightnvm/rrpc.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/lightnvm/rrpc.c b/drivers/lightnvm/rrpc.c
index d606c7a..cf1a4a5 100644
--- a/drivers/lightnvm/rrpc.c
+++ b/drivers/lightnvm/rrpc.c
@@ -202,6 +202,20 @@ static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
 	nvm_put_blk(rrpc->dev, rblk->parent);
 }
 
+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);
@@ -1224,18 +1238,21 @@ static int rrpc_luns_configure(struct rrpc *rrpc)
 
 		rblk = rrpc_get_blk(rrpc, rlun, 0);
 		if (!rblk)
-			return -EINVAL;
+			goto err;
 
 		rrpc_set_lun_cur(rlun, rblk);
 
 		/* Emergency gc block */
 		rblk = rrpc_get_blk(rrpc, rlun, 1);
 		if (!rblk)
-			return -EINVAL;
+			goto err;
 		rlun->gc_cur = rblk;
 	}
 
 	return 0;
+err:
+	rrpc_put_blks(rrpc);
+	return -EINVAL;
 }
 
 static struct nvm_tgt_type tt_rrpc;
-- 
2.1.4

[PATCH 3/9] lightnvm: refactor spin_unlock in gennvm_get_blk

[Matias Bjørling]

From: Wenwei Tao <ww.tao0320@gmail.com>

The spin_unlock is duplicated multiple times. Jump to a single unlock
to improve the code flow.

Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/lightnvm/gennvm.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/lightnvm/gennvm.c b/drivers/lightnvm/gennvm.c
index 35dde84..ce60254 100644
--- a/drivers/lightnvm/gennvm.c
+++ b/drivers/lightnvm/gennvm.c
@@ -262,14 +262,11 @@ static struct nvm_block *gennvm_get_blk(struct nvm_dev *dev,
 	if (list_empty(&lun->free_list)) {
 		pr_err_ratelimited("gennvm: lun %u have no free pages available",
 								lun->vlun.id);
-		spin_unlock(&vlun->lock);
 		goto out;
 	}
 
-	while (!is_gc && lun->vlun.nr_free_blocks < lun->reserved_blocks) {
-		spin_unlock(&vlun->lock);
+	if (!is_gc && lun->vlun.nr_free_blocks < lun->reserved_blocks)
 		goto out;
-	}
 
 	blk = list_first_entry(&lun->free_list, struct nvm_block, list);
 	list_move_tail(&blk->list, &lun->used_list);
@@ -278,8 +275,8 @@ static struct nvm_block *gennvm_get_blk(struct nvm_dev *dev,
 	lun->vlun.nr_free_blocks--;
 	lun->vlun.nr_inuse_blocks++;
 
-	spin_unlock(&vlun->lock);
 out:
+	spin_unlock(&vlun->lock);
 	return blk;
 }
 
-- 
2.1.4

[PATCH 4/9] lightnvm: check mm before use

[Matias Bjørling]

The core can may issue I/Os before a media manager is registered with
the lightnvm subsystem. Make sure that we don't call the media manager
->end_io prematurely with a null pointer.

Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/nvme/host/lightnvm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 06c3364..762c9a7 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -455,7 +455,7 @@ static void nvme_nvm_end_io(struct request *rq, int error)
 	struct nvm_rq *rqd = rq->end_io_data;
 	struct nvm_dev *dev = rqd->dev;
 
-	if (dev->mt->end_io(rqd, error))
+	if (dev->mt && dev->mt->end_io(rqd, error))
 		pr_err("nvme: err status: %x result: %lx\n",
 				rq->errors, (unsigned long)rq->special);
 
-- 
2.1.4

[PATCH 5/9] lightnvm: comments on constants

[Matias Bjørling]

It is not obvious what NVM_IO_* and NVM_BLK_T_* are used for. Make sure
to comment them appropriately as the other constants.

Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 include/linux/lightnvm.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index c6916ae..935ef38 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -50,9 +50,16 @@ enum {
 	NVM_IO_DUAL_ACCESS	= 0x1,
 	NVM_IO_QUAD_ACCESS	= 0x2,
 
+	/* NAND Access Modes */
 	NVM_IO_SUSPEND		= 0x80,
 	NVM_IO_SLC_MODE		= 0x100,
 	NVM_IO_SCRAMBLE_DISABLE	= 0x200,
+
+	/* Block Types */
+	NVM_BLK_T_FREE		= 0x0,
+	NVM_BLK_T_BAD		= 0x1,
+	NVM_BLK_T_DEV		= 0x2,
+	NVM_BLK_T_HOST		= 0x4,
 };
 
 struct nvm_id_group {
-- 
2.1.4

[PATCH 6/9] lightnvm: replace req queue with nvmdev for lld

[Matias Bjørling]

In the case where a request queue is passed to the low lever lightnvm
device drive integration, the device driver might pass its admin
commands through another queue. Instead pass nvm_dev, and let the
low level drive the appropriate queue.

Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/block/null_blk.c     |  9 +++++----
 drivers/lightnvm/core.c      |  7 +++----
 drivers/lightnvm/gennvm.c    |  8 ++++----
 drivers/lightnvm/rrpc.c      |  2 +-
 drivers/nvme/host/lightnvm.c | 24 +++++++++++++-----------
 include/linux/lightnvm.h     | 14 +++++++-------
 6 files changed, 33 insertions(+), 31 deletions(-)

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 0c3940e..7981b74 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -444,8 +444,9 @@ static void null_lnvm_end_io(struct request *rq, int error)
 	blk_put_request(rq);
 }
 
-static int null_lnvm_submit_io(struct request_queue *q, struct nvm_rq *rqd)
+static int null_lnvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 {
+	struct request_queue *q = dev->q;
 	struct request *rq;
 	struct bio *bio = rqd->bio;
 
@@ -470,7 +471,7 @@ static int null_lnvm_submit_io(struct request_queue *q, struct nvm_rq *rqd)
 	return 0;
 }
 
-static int null_lnvm_id(struct request_queue *q, struct nvm_id *id)
+static int null_lnvm_id(struct nvm_dev *dev, struct nvm_id *id)
 {
 	sector_t size = gb * 1024 * 1024 * 1024ULL;
 	sector_t blksize;
@@ -523,7 +524,7 @@ static int null_lnvm_id(struct request_queue *q, struct nvm_id *id)
 	return 0;
 }
 
-static void *null_lnvm_create_dma_pool(struct request_queue *q, char *name)
+static void *null_lnvm_create_dma_pool(struct nvm_dev *dev, char *name)
 {
 	mempool_t *virtmem_pool;
 
@@ -541,7 +542,7 @@ static void null_lnvm_destroy_dma_pool(void *pool)
 	mempool_destroy(pool);
 }
 
-static void *null_lnvm_dev_dma_alloc(struct request_queue *q, void *pool,
+static void *null_lnvm_dev_dma_alloc(struct nvm_dev *dev, void *pool,
 				gfp_t mem_flags, dma_addr_t *dma_handler)
 {
 	return mempool_alloc(pool, mem_flags);
diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 86ce887..4a8d1fe 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -74,7 +74,7 @@ EXPORT_SYMBOL(nvm_unregister_target);
 void *nvm_dev_dma_alloc(struct nvm_dev *dev, gfp_t mem_flags,
 							dma_addr_t *dma_handler)
 {
-	return dev->ops->dev_dma_alloc(dev->q, dev->ppalist_pool, mem_flags,
+	return dev->ops->dev_dma_alloc(dev, dev->ppalist_pool, mem_flags,
 								dma_handler);
 }
 EXPORT_SYMBOL(nvm_dev_dma_alloc);
@@ -246,7 +246,7 @@ static int nvm_init(struct nvm_dev *dev)
 	if (!dev->q || !dev->ops)
 		return ret;
 
-	if (dev->ops->identity(dev->q, &dev->identity)) {
+	if (dev->ops->identity(dev, &dev->identity)) {
 		pr_err("nvm: device could not be identified\n");
 		goto err;
 	}
@@ -326,8 +326,7 @@ int nvm_register(struct request_queue *q, char *disk_name,
 	}
 
 	if (dev->ops->max_phys_sect > 1) {
-		dev->ppalist_pool = dev->ops->create_dma_pool(dev->q,
-								"ppalist");
+		dev->ppalist_pool = dev->ops->create_dma_pool(dev, "ppalist");
 		if (!dev->ppalist_pool) {
 			pr_err("nvm: could not create ppa pool\n");
 			ret = -ENOMEM;
diff --git a/drivers/lightnvm/gennvm.c b/drivers/lightnvm/gennvm.c
index ce60254..52b513a 100644
--- a/drivers/lightnvm/gennvm.c
+++ b/drivers/lightnvm/gennvm.c
@@ -195,7 +195,7 @@ static int gennvm_blocks_init(struct nvm_dev *dev, struct gen_nvm *gn)
 	}
 
 	if (dev->ops->get_l2p_tbl) {
-		ret = dev->ops->get_l2p_tbl(dev->q, 0, dev->total_pages,
+		ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_pages,
 							gennvm_block_map, dev);
 		if (ret) {
 			pr_err("gennvm: could not read L2P table.\n");
@@ -346,7 +346,7 @@ static int gennvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 	gennvm_generic_to_addr_mode(dev, rqd);
 
 	rqd->dev = dev;
-	return dev->ops->submit_io(dev->q, rqd);
+	return dev->ops->submit_io(dev, rqd);
 }
 
 static void gennvm_blk_set_type(struct nvm_dev *dev, struct ppa_addr *ppa,
@@ -382,7 +382,7 @@ static void gennvm_mark_blk_bad(struct nvm_dev *dev, struct nvm_rq *rqd)
 	if (!dev->ops->set_bb_tbl)
 		return;
 
-	if (dev->ops->set_bb_tbl(dev->q, rqd, 1))
+	if (dev->ops->set_bb_tbl(dev, rqd, 1))
 		return;
 
 	gennvm_addr_to_generic_mode(dev, rqd);
@@ -450,7 +450,7 @@ static int gennvm_erase_blk(struct nvm_dev *dev, struct nvm_block *blk,
 
 	gennvm_generic_to_addr_mode(dev, &rqd);
 
-	ret = dev->ops->erase_block(dev->q, &rqd);
+	ret = dev->ops->erase_block(dev, &rqd);
 
 	if (plane_cnt)
 		nvm_dev_dma_free(dev, rqd.ppa_list, rqd.dma_ppa_list);
diff --git a/drivers/lightnvm/rrpc.c b/drivers/lightnvm/rrpc.c
index cf1a4a5..134e4fa 100644
--- a/drivers/lightnvm/rrpc.c
+++ b/drivers/lightnvm/rrpc.c
@@ -1016,7 +1016,7 @@ static int rrpc_map_init(struct rrpc *rrpc)
 		return 0;
 
 	/* Bring up the mapping table from device */
-	ret = dev->ops->get_l2p_tbl(dev->q, 0, dev->total_pages,
+	ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_pages,
 							rrpc_l2p_update, rrpc);
 	if (ret) {
 		pr_err("nvm: rrpc: could not read L2P table.\n");
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 762c9a7..15f2acb 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -271,9 +271,9 @@ static int init_grps(struct nvm_id *nvm_id, struct nvme_nvm_id *nvme_nvm_id)
 	return 0;
 }
 
-static int nvme_nvm_identity(struct request_queue *q, struct nvm_id *nvm_id)
+static int nvme_nvm_identity(struct nvm_dev *nvmdev, struct nvm_id *nvm_id)
 {
-	struct nvme_ns *ns = q->queuedata;
+	struct nvme_ns *ns = nvmdev->q->queuedata;
 	struct nvme_dev *dev = ns->dev;
 	struct nvme_nvm_id *nvme_nvm_id;
 	struct nvme_nvm_command c = {};
@@ -308,10 +308,10 @@ out:
 	return ret;
 }
 
-static int nvme_nvm_get_l2p_tbl(struct request_queue *q, u64 slba, u32 nlb,
+static int nvme_nvm_get_l2p_tbl(struct nvm_dev *nvmdev, u64 slba, u32 nlb,
 				nvm_l2p_update_fn *update_l2p, void *priv)
 {
-	struct nvme_ns *ns = q->queuedata;
+	struct nvme_ns *ns = nvmdev->q->queuedata;
 	struct nvme_dev *dev = ns->dev;
 	struct nvme_nvm_command c = {};
 	u32 len = queue_max_hw_sectors(dev->admin_q) << 9;
@@ -415,10 +415,10 @@ out:
 	return ret;
 }
 
-static int nvme_nvm_set_bb_tbl(struct request_queue *q, struct nvm_rq *rqd,
+static int nvme_nvm_set_bb_tbl(struct nvm_dev *nvmdev, struct nvm_rq *rqd,
 								int type)
 {
-	struct nvme_ns *ns = q->queuedata;
+	struct nvme_ns *ns = nvmdev->q->queuedata;
 	struct nvme_dev *dev = ns->dev;
 	struct nvme_nvm_command c = {};
 	int ret = 0;
@@ -463,8 +463,9 @@ static void nvme_nvm_end_io(struct request *rq, int error)
 	blk_mq_free_request(rq);
 }
 
-static int nvme_nvm_submit_io(struct request_queue *q, struct nvm_rq *rqd)
+static int nvme_nvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 {
+	struct request_queue *q = dev->q;
 	struct nvme_ns *ns = q->queuedata;
 	struct request *rq;
 	struct bio *bio = rqd->bio;
@@ -502,8 +503,9 @@ static int nvme_nvm_submit_io(struct request_queue *q, struct nvm_rq *rqd)
 	return 0;
 }
 
-static int nvme_nvm_erase_block(struct request_queue *q, struct nvm_rq *rqd)
+static int nvme_nvm_erase_block(struct nvm_dev *dev, struct nvm_rq *rqd)
 {
+	struct request_queue *q = dev->q;
 	struct nvme_ns *ns = q->queuedata;
 	struct nvme_nvm_command c = {};
 
@@ -515,9 +517,9 @@ static int nvme_nvm_erase_block(struct request_queue *q, struct nvm_rq *rqd)
 	return nvme_submit_sync_cmd(q, (struct nvme_command *)&c, NULL, 0);
 }
 
-static void *nvme_nvm_create_dma_pool(struct request_queue *q, char *name)
+static void *nvme_nvm_create_dma_pool(struct nvm_dev *nvmdev, char *name)
 {
-	struct nvme_ns *ns = q->queuedata;
+	struct nvme_ns *ns = nvmdev->q->queuedata;
 	struct nvme_dev *dev = ns->dev;
 
 	return dma_pool_create(name, dev->dev, PAGE_SIZE, PAGE_SIZE, 0);
@@ -530,7 +532,7 @@ static void nvme_nvm_destroy_dma_pool(void *pool)
 	dma_pool_destroy(dma_pool);
 }
 
-static void *nvme_nvm_dev_dma_alloc(struct request_queue *q, void *pool,
+static void *nvme_nvm_dev_dma_alloc(struct nvm_dev *dev, void *pool,
 				    gfp_t mem_flags, dma_addr_t *dma_handler)
 {
 	return dma_pool_alloc(pool, mem_flags, dma_handler);
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index 935ef38..034117b 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -183,17 +183,17 @@ struct nvm_block;
 
 typedef int (nvm_l2p_update_fn)(u64, u32, __le64 *, void *);
 typedef int (nvm_bb_update_fn)(struct ppa_addr, int, u8 *, void *);
-typedef int (nvm_id_fn)(struct request_queue *, struct nvm_id *);
-typedef int (nvm_get_l2p_tbl_fn)(struct request_queue *, u64, u32,
+typedef int (nvm_id_fn)(struct nvm_dev *, struct nvm_id *);
+typedef int (nvm_get_l2p_tbl_fn)(struct nvm_dev *, u64, u32,
 				nvm_l2p_update_fn *, void *);
 typedef int (nvm_op_bb_tbl_fn)(struct nvm_dev *, struct ppa_addr, int,
 				nvm_bb_update_fn *, void *);
-typedef int (nvm_op_set_bb_fn)(struct request_queue *, struct nvm_rq *, int);
-typedef int (nvm_submit_io_fn)(struct request_queue *, struct nvm_rq *);
-typedef int (nvm_erase_blk_fn)(struct request_queue *, struct nvm_rq *);
-typedef void *(nvm_create_dma_pool_fn)(struct request_queue *, char *);
+typedef int (nvm_op_set_bb_fn)(struct nvm_dev *, struct nvm_rq *, int);
+typedef int (nvm_submit_io_fn)(struct nvm_dev *, struct nvm_rq *);
+typedef int (nvm_erase_blk_fn)(struct nvm_dev *, struct nvm_rq *);
+typedef void *(nvm_create_dma_pool_fn)(struct nvm_dev *, char *);
 typedef void (nvm_destroy_dma_pool_fn)(void *);
-typedef void *(nvm_dev_dma_alloc_fn)(struct request_queue *, void *, gfp_t,
+typedef void *(nvm_dev_dma_alloc_fn)(struct nvm_dev *, void *, gfp_t,
 								dma_addr_t *);
 typedef void (nvm_dev_dma_free_fn)(void *, void*, dma_addr_t);
 
-- 
2.1.4

[PATCH 7/9] lightnvm: fix media mgr registration

[Matias Bjørling]

This patch fixes two issues during media manager registration.

1. The ppa pool can be used at media manager registration. Allocate the
ppa pool before that.

2. If a media manager can't be found, this should not lead to the
device being unallocated. A media manager can be registered later, that
can manage the device. Only warn if a media manager fails
initialization.

Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/lightnvm/core.c | 78 ++++++++++++++++++++++++-------------------------
 1 file changed, 39 insertions(+), 39 deletions(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 4a8d1fe..8f41b24 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -97,15 +97,47 @@ static struct nvmm_type *nvm_find_mgr_type(const char *name)
 	return NULL;
 }
 
+struct nvmm_type *nvm_init_mgr(struct nvm_dev *dev)
+{
+	struct nvmm_type *mt;
+	int ret;
+
+	lockdep_assert_held(&nvm_lock);
+
+	list_for_each_entry(mt, &nvm_mgrs, list) {
+		ret = mt->register_mgr(dev);
+		if (ret < 0) {
+			pr_err("nvm: media mgr failed to init (%d) on dev %s\n",
+								ret, dev->name);
+			return NULL; /* initialization failed */
+		} else if (ret > 0)
+			return mt;
+	}
+
+	return NULL;
+}
+
 int nvm_register_mgr(struct nvmm_type *mt)
 {
+	struct nvm_dev *dev;
 	int ret = 0;
 
 	down_write(&nvm_lock);
-	if (nvm_find_mgr_type(mt->name))
+	if (nvm_find_mgr_type(mt->name)) {
 		ret = -EEXIST;
-	else
+		goto finish;
+	} else {
 		list_add(&mt->list, &nvm_mgrs);
+	}
+
+	/* try to register media mgr if any device have none configured */
+	list_for_each_entry(dev, &nvm_devices, devices) {
+		if (dev->mt)
+			continue;
+
+		dev->mt = nvm_init_mgr(dev);
+	}
+finish:
 	up_write(&nvm_lock);
 
 	return ret;
@@ -123,26 +155,6 @@ void nvm_unregister_mgr(struct nvmm_type *mt)
 }
 EXPORT_SYMBOL(nvm_unregister_mgr);
 
-/* register with device with a supported manager */
-static int register_mgr(struct nvm_dev *dev)
-{
-	struct nvmm_type *mt;
-	int ret = 0;
-
-	list_for_each_entry(mt, &nvm_mgrs, list) {
-		ret = mt->register_mgr(dev);
-		if (ret > 0) {
-			dev->mt = mt;
-			break; /* successfully initialized */
-		}
-	}
-
-	if (!ret)
-		pr_info("nvm: no compatible nvm manager found.\n");
-
-	return ret;
-}
-
 static struct nvm_dev *nvm_find_nvm_dev(const char *name)
 {
 	struct nvm_dev *dev;
@@ -271,14 +283,6 @@ static int nvm_init(struct nvm_dev *dev)
 		goto err;
 	}
 
-	down_write(&nvm_lock);
-	ret = register_mgr(dev);
-	up_write(&nvm_lock);
-	if (ret < 0)
-		goto err;
-	if (!ret)
-		return 0;
-
 	pr_info("nvm: registered %s [%u/%u/%u/%u/%u/%u]\n",
 			dev->name, dev->sec_per_pg, dev->nr_planes,
 			dev->pgs_per_blk, dev->blks_per_lun, dev->nr_luns,
@@ -334,7 +338,9 @@ int nvm_register(struct request_queue *q, char *disk_name,
 		}
 	}
 
+	/* register device with a supported media manager */
 	down_write(&nvm_lock);
+	dev->mt = nvm_init_mgr(dev);
 	list_add(&dev->devices, &nvm_devices);
 	up_write(&nvm_lock);
 
@@ -379,19 +385,13 @@ static int nvm_create_target(struct nvm_dev *dev,
 	struct nvm_tgt_type *tt;
 	struct nvm_target *t;
 	void *targetdata;
-	int ret = 0;
 
-	down_write(&nvm_lock);
 	if (!dev->mt) {
-		ret = register_mgr(dev);
-		if (!ret)
-			ret = -ENODEV;
-		if (ret < 0) {
-			up_write(&nvm_lock);
-			return ret;
-		}
+		pr_info("nvm: device has no media manager registered.\n");
+		return -ENODEV;
 	}
 
+	down_write(&nvm_lock);
 	tt = nvm_find_target_type(create->tgttype);
 	if (!tt) {
 		pr_err("nvm: target type %s not found\n", create->tgttype);
-- 
2.1.4

[PATCH 8/9] lightnvm: prevent gennvm module unload on use

[Matias Bjørling]

After the gennvm module has been initialized. It might be attached to
one or several devices. In that case, the module is in use. Make sure
that it can not be unloaded.

Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/lightnvm/gennvm.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/lightnvm/gennvm.c b/drivers/lightnvm/gennvm.c
index 52b513a..f434e89 100644
--- a/drivers/lightnvm/gennvm.c
+++ b/drivers/lightnvm/gennvm.c
@@ -219,6 +219,9 @@ static int gennvm_register(struct nvm_dev *dev)
 	struct gen_nvm *gn;
 	int ret;
 
+	if (!try_module_get(THIS_MODULE))
+		return -ENODEV;
+
 	gn = kzalloc(sizeof(struct gen_nvm), GFP_KERNEL);
 	if (!gn)
 		return -ENOMEM;
@@ -242,12 +245,14 @@ static int gennvm_register(struct nvm_dev *dev)
 	return 1;
 err:
 	gennvm_free(dev);
+	module_put(THIS_MODULE);
 	return ret;
 }
 
 static void gennvm_unregister(struct nvm_dev *dev)
 {
 	gennvm_free(dev);
+	module_put(THIS_MODULE);
 }
 
 static struct nvm_block *gennvm_get_blk(struct nvm_dev *dev,
-- 
2.1.4

[PATCH 9/9] lightnvm: do not compile in debugging by default

[Matias Bjørling]

The LightNVM module exposes a debug interface when CONFIG_NVM_DEBUG is
set. This interfaces takes a string to configure media managers and
targets. Make sure this interface is only exposed when chosen
deliberately.

Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/lightnvm/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/lightnvm/Kconfig b/drivers/lightnvm/Kconfig
index a16bf56..85a3390 100644
--- a/drivers/lightnvm/Kconfig
+++ b/drivers/lightnvm/Kconfig
@@ -18,6 +18,7 @@ if NVM
 
 config NVM_DEBUG
 	bool "Open-Channel SSD debugging support"
+	default n
 	---help---
 	Exposes a debug management interface to create/remove targets at:
 
-- 
2.1.4

Re: [PATCH 0/9] Fixes for LightNVM

[Jens Axboe]

On Sun, Dec 06 2015, Matias Bjørling wrote:
> Hi Jens,
> 
> A couple more fixes for LightNVM.
> 
> The first three patches are fixed from Tao on rrpc and gennvm. The next
> five patches are small fixes and refactoring to prepare for system
> blocks. The last patch defaults debugging to not be compiled in and
> thereby not expose the parameter configuration interface.
> 
> Thanks! Please pick up when convenient.

Applied for 4.4. Let's ensure that we push new developments to a 4.5
related branch, and only submit for 4.4 what really needs to go into
4.4.

-- 
Jens Axboe

Re: [PATCH 0/9] Fixes for LightNVM

[Matias Bjørling]

On Mon, Dec 7, 2015 at 5:11 PM, Jens Axboe <axboe@fb.com> wrote:
> On Sun, Dec 06 2015, Matias Bjørling wrote:
>> Hi Jens,
>>
>> A couple more fixes for LightNVM.
>>
>> The first three patches are fixed from Tao on rrpc and gennvm. The next
>> five patches are small fixes and refactoring to prepare for system
>> blocks. The last patch defaults debugging to not be compiled in and
>> thereby not expose the parameter configuration interface.
>>
>> Thanks! Please pick up when convenient.
>
> Applied for 4.4. Let's ensure that we push new developments to a 4.5
> related branch, and only submit for 4.4 what really needs to go into
> 4.4.

Thanks Jens. Will do. Already have a couple larger ones queued up wrt
to recovery. :)