lightnvm: manage open and closed blocks separately
LightNVM targets need to know the state of the flash block when doing
flash optimizations. An example is implementing a write buffer to
respect the flash page size. Currently, block state is not accounted
for; the media manager only differentiates among free, bad and in-use
blocks.
This patch adds the logic in the generic media manager to enable
targets manage blocks into open and close separately, and it implements
such management in rrpc. It also adds a set of flags to describe the
state of the block (open, closed, free, bad).
In order to avoid taking two locks (nvm_lun and rrpc_lun) consecutively,
we introduce lockless get_/put_block primitives so that the open and
close list locks and future common logic is handled within the nvm_lun
lock.
Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/lightnvm/gennvm.c b/drivers/lightnvm/gennvm.c
index 4c15846..7fb725b 100644
--- a/drivers/lightnvm/gennvm.c
+++ b/drivers/lightnvm/gennvm.c
@@ -60,7 +60,8 @@
lun->vlun.lun_id = i % dev->luns_per_chnl;
lun->vlun.chnl_id = i / dev->luns_per_chnl;
lun->vlun.nr_free_blocks = dev->blks_per_lun;
- lun->vlun.nr_inuse_blocks = 0;
+ lun->vlun.nr_open_blocks = 0;
+ lun->vlun.nr_closed_blocks = 0;
lun->vlun.nr_bad_blocks = 0;
}
return 0;
@@ -134,15 +135,15 @@
pba = pba - (dev->sec_per_lun * lun_id);
blk = &lun->vlun.blocks[div_u64(pba, dev->sec_per_blk)];
- if (!blk->type) {
+ if (!blk->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
+ * block state. The block is assumed to be open.
*/
list_move_tail(&blk->list, &lun->used_list);
- blk->type = 1;
+ blk->state = NVM_BLK_ST_OPEN;
lun->vlun.nr_free_blocks--;
- lun->vlun.nr_inuse_blocks++;
+ lun->vlun.nr_open_blocks++;
}
}
@@ -256,14 +257,14 @@
module_put(THIS_MODULE);
}
-static struct nvm_block *gennvm_get_blk(struct nvm_dev *dev,
+static struct nvm_block *gennvm_get_blk_unlocked(struct nvm_dev *dev,
struct nvm_lun *vlun, unsigned long flags)
{
struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
struct nvm_block *blk = NULL;
int is_gc = flags & NVM_IOTYPE_GC;
- spin_lock(&vlun->lock);
+ assert_spin_locked(&vlun->lock);
if (list_empty(&lun->free_list)) {
pr_err_ratelimited("gennvm: lun %u have no free pages available",
@@ -276,44 +277,63 @@
blk = list_first_entry(&lun->free_list, struct nvm_block, list);
list_move_tail(&blk->list, &lun->used_list);
- blk->type = 1;
+ blk->state = NVM_BLK_ST_OPEN;
lun->vlun.nr_free_blocks--;
- lun->vlun.nr_inuse_blocks++;
+ lun->vlun.nr_open_blocks++;
out:
+ return blk;
+}
+
+static struct nvm_block *gennvm_get_blk(struct nvm_dev *dev,
+ struct nvm_lun *vlun, unsigned long flags)
+{
+ struct nvm_block *blk;
+
+ spin_lock(&vlun->lock);
+ blk = gennvm_get_blk_unlocked(dev, vlun, flags);
spin_unlock(&vlun->lock);
return blk;
}
+static void gennvm_put_blk_unlocked(struct nvm_dev *dev, struct nvm_block *blk)
+{
+ struct nvm_lun *vlun = blk->lun;
+ struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
+
+ assert_spin_locked(&vlun->lock);
+
+ if (blk->state & NVM_BLK_ST_OPEN) {
+ list_move_tail(&blk->list, &lun->free_list);
+ lun->vlun.nr_open_blocks--;
+ lun->vlun.nr_free_blocks++;
+ blk->state = NVM_BLK_ST_FREE;
+ } else if (blk->state & NVM_BLK_ST_CLOSED) {
+ list_move_tail(&blk->list, &lun->free_list);
+ lun->vlun.nr_closed_blocks--;
+ lun->vlun.nr_free_blocks++;
+ blk->state = NVM_BLK_ST_FREE;
+ } else if (blk->state & NVM_BLK_ST_BAD) {
+ list_move_tail(&blk->list, &lun->bb_list);
+ lun->vlun.nr_bad_blocks++;
+ blk->state = NVM_BLK_ST_BAD;
+ } else {
+ WARN_ON_ONCE(1);
+ pr_err("gennvm: erroneous block type (%lu -> %u)\n",
+ blk->id, blk->state);
+ list_move_tail(&blk->list, &lun->bb_list);
+ lun->vlun.nr_bad_blocks++;
+ blk->state = NVM_BLK_ST_BAD;
+ }
+}
+
static void gennvm_put_blk(struct nvm_dev *dev, struct nvm_block *blk)
{
struct nvm_lun *vlun = blk->lun;
- struct gen_lun *lun = container_of(vlun, struct gen_lun, vlun);
spin_lock(&vlun->lock);
-
- switch (blk->type) {
- case 1:
- list_move_tail(&blk->list, &lun->free_list);
- lun->vlun.nr_free_blocks++;
- lun->vlun.nr_inuse_blocks--;
- blk->type = 0;
- break;
- case 2:
- list_move_tail(&blk->list, &lun->bb_list);
- lun->vlun.nr_bad_blocks++;
- lun->vlun.nr_inuse_blocks--;
- break;
- default:
- WARN_ON_ONCE(1);
- pr_err("gennvm: erroneous block type (%lu -> %u)\n",
- blk->id, blk->type);
- list_move_tail(&blk->list, &lun->bb_list);
- lun->vlun.nr_bad_blocks++;
- lun->vlun.nr_inuse_blocks--;
- }
-
+ gennvm_put_blk_unlocked(dev, blk);
spin_unlock(&vlun->lock);
}
@@ -339,7 +359,7 @@
blk = &lun->vlun.blocks[ppa->g.blk];
/* will be moved to bb list on put_blk from target */
- blk->type = type;
+ blk->state = type;
}
/* mark block bad. It is expected the target recover from the error. */
@@ -358,9 +378,10 @@
/* look up blocks and mark them as bad */
if (rqd->nr_pages > 1)
for (i = 0; i < rqd->nr_pages; i++)
- gennvm_blk_set_type(dev, &rqd->ppa_list[i], 2);
+ gennvm_blk_set_type(dev, &rqd->ppa_list[i],
+ NVM_BLK_ST_BAD);
else
- gennvm_blk_set_type(dev, &rqd->ppa_addr, 2);
+ gennvm_blk_set_type(dev, &rqd->ppa_addr, NVM_BLK_ST_BAD);
}
static void gennvm_end_io(struct nvm_rq *rqd)
@@ -416,10 +437,11 @@
gennvm_for_each_lun(gn, lun, i) {
spin_lock(&lun->vlun.lock);
- pr_info("%s: lun%8u\t%u\t%u\t%u\n",
+ pr_info("%s: lun%8u\t%u\t%u\t%u\t%u\n",
dev->name, i,
lun->vlun.nr_free_blocks,
- lun->vlun.nr_inuse_blocks,
+ lun->vlun.nr_open_blocks,
+ lun->vlun.nr_closed_blocks,
lun->vlun.nr_bad_blocks);
spin_unlock(&lun->vlun.lock);
@@ -427,20 +449,23 @@
}
static struct nvmm_type gennvm = {
- .name = "gennvm",
- .version = {0, 1, 0},
+ .name = "gennvm",
+ .version = {0, 1, 0},
- .register_mgr = gennvm_register,
- .unregister_mgr = gennvm_unregister,
+ .register_mgr = gennvm_register,
+ .unregister_mgr = gennvm_unregister,
- .get_blk = gennvm_get_blk,
- .put_blk = gennvm_put_blk,
+ .get_blk_unlocked = gennvm_get_blk_unlocked,
+ .put_blk_unlocked = gennvm_put_blk_unlocked,
- .submit_io = gennvm_submit_io,
- .erase_blk = gennvm_erase_blk,
+ .get_blk = gennvm_get_blk,
+ .put_blk = gennvm_put_blk,
- .get_lun = gennvm_get_lun,
- .lun_info_print = gennvm_lun_info_print,
+ .submit_io = gennvm_submit_io,
+ .erase_blk = gennvm_erase_blk,
+
+ .get_lun = gennvm_get_lun,
+ .lun_info_print = gennvm_lun_info_print,
};
static int __init gennvm_module_init(void)