lightnvm: pblk: use exact free block counter in RL

Until now, pblk's rate-limiter has used a heuristic to reserve space for
GC I/O given that the over-provision area was fixed.

In preparation for allowing to define the over-provision area on target
creation, define a dedicated free_block counter in the rate-limiter to
track the number of blocks being used for user data.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 6 insertions, 13 deletions

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 54d0cef7116e..5ec7ad68ff38 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -1145,7 +1145,7 @@ int pblk_line_recov_alloc(struct pblk *pblk, struct pblk_line *line)
 	}
 	spin_unlock(&l_mg->free_lock);
 
-	pblk_rl_free_lines_dec(&pblk->rl, line);
+	pblk_rl_free_lines_dec(&pblk->rl, line, true);
 
 	if (!pblk_line_init_bb(pblk, line, 0)) {
 		list_add(&line->list, &l_mg->free_list);
@@ -1233,7 +1233,7 @@ retry:
 	l_mg->data_line = retry_line;
 	spin_unlock(&l_mg->free_lock);
 
-	pblk_rl_free_lines_dec(&pblk->rl, retry_line);
+	pblk_rl_free_lines_dec(&pblk->rl, line, false);
 
 	if (pblk_line_erase(pblk, retry_line))
 		goto retry;
@@ -1252,7 +1252,6 @@ struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 {
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line *line;
-	int is_next = 0;
 
 	spin_lock(&l_mg->free_lock);
 	line = pblk_line_get(pblk);
@@ -1280,7 +1279,6 @@ struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 	} else {
 		l_mg->data_next->seq_nr = l_mg->d_seq_nr++;
 		l_mg->data_next->type = PBLK_LINETYPE_DATA;
-		is_next = 1;
 	}
 	spin_unlock(&l_mg->free_lock);
 
@@ -1290,10 +1288,6 @@ struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 			return NULL;
 	}
 
-	pblk_rl_free_lines_dec(&pblk->rl, line);
-	if (is_next)
-		pblk_rl_free_lines_dec(&pblk->rl, l_mg->data_next);
-
 retry_setup:
 	if (!pblk_line_init_metadata(pblk, line, NULL)) {
 		line = pblk_line_retry(pblk, line);
@@ -1311,6 +1305,8 @@ retry_setup:
 		goto retry_setup;
 	}
 
+	pblk_rl_free_lines_dec(&pblk->rl, line, true);
+
 	return line;
 }
 
@@ -1395,7 +1391,6 @@ struct pblk_line *pblk_line_replace_data(struct pblk *pblk)
 	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 	struct pblk_line *cur, *new = NULL;
 	unsigned int left_seblks;
-	int is_next = 0;
 
 	cur = l_mg->data_line;
 	new = l_mg->data_next;
@@ -1444,6 +1439,8 @@ retry_setup:
 		goto retry_setup;
 	}
 
+	pblk_rl_free_lines_dec(&pblk->rl, new, true);
+
 	/* Allocate next line for preparation */
 	spin_lock(&l_mg->free_lock);
 	l_mg->data_next = pblk_line_get(pblk);
@@ -1457,13 +1454,9 @@ retry_setup:
 	} else {
 		l_mg->data_next->seq_nr = l_mg->d_seq_nr++;
 		l_mg->data_next->type = PBLK_LINETYPE_DATA;
-		is_next = 1;
 	}
 	spin_unlock(&l_mg->free_lock);
 
-	if (is_next)
-		pblk_rl_free_lines_dec(&pblk->rl, l_mg->data_next);
-
 out:
 	return new;
 }