[PATCH v2] lightnvm: pblk: refactor put line fn on read completion

["Matias Bjørling" <mb@lightnvm.io>]

The read completion path uses the put_line variable to decide whether
the reference on a line should be released. The function name used for
that is pblk_read_put_rqd_kref, which could lead one to believe that it
is the rqd that is releasing the reference, while it is the line
reference that is put.

Rename and also split the function in two to account for either rqd or
single ppa callers and move it to core, such that it later can be used
in the write path as well.

Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Reviewed-by: Javier González <javier@cnexlabs.com>
Reviewed-by: Heiner Litz <hlitz@ucsc.edu>

Changes since v1:

  Moved into core for Heiner to later integrate with his RAIL
  patches.
---
 drivers/lightnvm/pblk-core.c | 19 +++++++++++++++++++
 drivers/lightnvm/pblk-read.c | 18 +-----------------
 drivers/lightnvm/pblk.h      |  2 ++
 3 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index e0b513d07e14..5f99cf396072 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -1426,6 +1426,25 @@ struct pblk_line *pblk_line_get_first_data(struct pblk *pblk)
 	return line;
 }
 
+void pblk_ppa_to_line_put(struct pblk *pblk, struct ppa_addr ppa)
+{
+	struct pblk_line *line;
+
+	line = &pblk->lines[pblk_ppa_to_line(ppa)];
+	kref_put(&line->ref, pblk_line_put_wq);
+}
+
+void pblk_rq_to_line_put(struct pblk *pblk, struct nvm_rq *rqd)
+{
+	struct ppa_addr *ppa_list;
+	int i;
+
+	ppa_list = (rqd->nr_ppas > 1) ? rqd->ppa_list : &rqd->ppa_addr;
+
+	for (i = 0; i < rqd->nr_ppas; i++)
+		pblk_ppa_to_line_put(pblk, ppa_list[i]);
+}
+
 static void pblk_stop_writes(struct pblk *pblk, struct pblk_line *line)
 {
 	lockdep_assert_held(&pblk->l_mg.free_lock);
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
index 1ad501721d0f..dc8233f3fd6c 100644
--- a/drivers/lightnvm/pblk-read.c
+++ b/drivers/lightnvm/pblk-read.c
@@ -165,22 +165,6 @@ static void pblk_read_check_rand(struct pblk *pblk, struct nvm_rq *rqd,
 	WARN_ONCE(j != rqd->nr_ppas, "pblk: corrupted random request\n");
 }
 
-static void pblk_read_put_rqd_kref(struct pblk *pblk, struct nvm_rq *rqd)
-{
-	struct ppa_addr *ppa_list;
-	int i;
-
-	ppa_list = (rqd->nr_ppas > 1) ? rqd->ppa_list : &rqd->ppa_addr;
-
-	for (i = 0; i < rqd->nr_ppas; i++) {
-		struct ppa_addr ppa = ppa_list[i];
-		struct pblk_line *line;
-
-		line = &pblk->lines[pblk_ppa_to_line(ppa)];
-		kref_put(&line->ref, pblk_line_put_wq);
-	}
-}
-
 static void pblk_end_user_read(struct bio *bio)
 {
 #ifdef CONFIG_NVM_PBLK_DEBUG
@@ -208,7 +192,7 @@ static void __pblk_end_io_read(struct pblk *pblk, struct nvm_rq *rqd,
 		bio_put(int_bio);
 
 	if (put_line)
-		pblk_read_put_rqd_kref(pblk, rqd);
+		pblk_rq_to_line_put(pblk, rqd);
 
 #ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(rqd->nr_ppas, &pblk->sync_reads);
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 64ae0c7ed3bb..be67bbfa3d0a 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -787,6 +787,8 @@ struct bio *pblk_bio_map_addr(struct pblk *pblk, void *data,
 struct pblk_line *pblk_line_get(struct pblk *pblk);
 struct pblk_line *pblk_line_get_first_data(struct pblk *pblk);
 struct pblk_line *pblk_line_replace_data(struct pblk *pblk);
+void pblk_ppa_to_line_put(struct pblk *pblk, struct ppa_addr ppa);
+void pblk_rq_to_line_put(struct pblk *pblk, struct nvm_rq *rqd);
 int pblk_line_recov_alloc(struct pblk *pblk, struct pblk_line *line);
 void pblk_line_recov_close(struct pblk *pblk, struct pblk_line *line);
 struct pblk_line *pblk_line_get_data(struct pblk *pblk);
-- 
2.11.0