diff options
| -rw-r--r-- | block/blk-mq-tag.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 6deb13055490..08fc6716d362 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -344,6 +344,7 @@ static void bt_clear_tag(struct blk_mq_bitmap_tags *bt, unsigned int tag) { const int index = TAG_TO_INDEX(bt, tag); struct bt_wait_state *bs; + int wait_cnt; /* * The unlock memory barrier need to order access to req in free @@ -352,10 +353,19 @@ static void bt_clear_tag(struct blk_mq_bitmap_tags *bt, unsigned int tag) clear_bit_unlock(TAG_TO_BIT(bt, tag), &bt->map[index].word); bs = bt_wake_ptr(bt); - if (bs && atomic_dec_and_test(&bs->wait_cnt)) { - atomic_set(&bs->wait_cnt, bt->wake_cnt); + if (!bs) + return; + + wait_cnt = atomic_dec_return(&bs->wait_cnt); + if (wait_cnt == 0) { +wake: + atomic_add(bt->wake_cnt, &bs->wait_cnt); bt_index_atomic_inc(&bt->wake_index); wake_up(&bs->wait); + } else if (wait_cnt < 0) { + wait_cnt = atomic_inc_return(&bs->wait_cnt); + if (!wait_cnt) + goto wake; } } |