[PATCH 2/4] blk-throtl: don't warn in tg_drain_bios()

From: Yu Kuai
Date: Wed Sep 22 2021 - 08:41:50 EST


tg_drain_bios() will iterate until throtl_rb_first() return NULL,
don't warn in such situation.

Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
block/blk-throttle.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 43dee985170b..3892ead7a0b5 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -644,12 +644,13 @@ static void throtl_pd_free(struct blkg_policy_data *pd)
}

static struct throtl_grp *
-throtl_rb_first(struct throtl_service_queue *parent_sq)
+throtl_rb_first(struct throtl_service_queue *parent_sq, bool warn)
{
struct rb_node *n;

n = rb_first_cached(&parent_sq->pending_tree);
- WARN_ON_ONCE(!n);
+ if (warn)
+ WARN_ON_ONCE(!n);
if (!n)
return NULL;
return rb_entry_tg(n);
@@ -667,7 +668,7 @@ static void update_min_dispatch_time(struct throtl_service_queue *parent_sq)
{
struct throtl_grp *tg;

- tg = throtl_rb_first(parent_sq);
+ tg = throtl_rb_first(parent_sq, true);
if (!tg)
return;

@@ -1236,7 +1237,7 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq)
if (!parent_sq->nr_pending)
break;

- tg = throtl_rb_first(parent_sq);
+ tg = throtl_rb_first(parent_sq, true);
if (!tg)
break;

@@ -2421,7 +2422,7 @@ static void tg_drain_bios(struct throtl_service_queue *parent_sq)
{
struct throtl_grp *tg;

- while ((tg = throtl_rb_first(parent_sq))) {
+ while ((tg = throtl_rb_first(parent_sq, false))) {
struct throtl_service_queue *sq = &tg->service_queue;
struct bio *bio;

--
2.31.1