block: extend queue bypassing to cover blkcg policies

Extend queue bypassing such that dying queue is always bypassing and
blk-throttle is drained on bypass.  With blkcg policies updated to
test blk_queue_bypass() instead of blk_queue_dead(), this ensures that
no bio or request is held by or going through blkcg policies on a
bypassing queue.

This will be used to implement blkg cleanup on elevator switches and
policy changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 2 insertions, 2 deletions

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 5eed6a76721..702c0e64e09 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -310,7 +310,7 @@ static struct throtl_grp * throtl_get_tg(struct throtl_data *td)
         struct request_queue *q = td->queue;
 
         /* no throttling for dead queue */
-        if (unlikely(blk_queue_dead(q)))
+        if (unlikely(blk_queue_bypass(q)))
                 return NULL;
 
         rcu_read_lock();
@@ -335,7 +335,7 @@ static struct throtl_grp * throtl_get_tg(struct throtl_data *td)
         spin_lock_irq(q->queue_lock);
 
         /* Make sure @q is still alive */
-        if (unlikely(blk_queue_dead(q))) {
+        if (unlikely(blk_queue_bypass(q))) {
                 kfree(tg);
                 return NULL;
         }