Serialize these operations because a later patch will add code into
blk_pre_runtime_suspend() that should not run concurrently with queue
freezing nor unfreezing.

Signed-off-by: Bart Van Assche <redacted>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jianchao Wang <redacted>
Cc: Ming Lei <redacted>
Cc: Johannes Thumshirn <redacted>
Cc: Alan Stern <stern@rowland.harvard.edu>
---
 block/blk-core.c       |  5 +++++
 block/blk-mq.c         |  3 +++
 block/blk-pm.c         | 44 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/blk-pm.h |  6 ++++++
 include/linux/blkdev.h |  5 +++++
 5 files changed, 63 insertions(+)

diff --git a/block/blk-core.c b/block/blk-core.c
index 03cff7445dee..59382c758155 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c

@@ -17,6 +17,7 @@
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 #include <linux/blk-mq.h>
+#include <linux/blk-pm.h>
 #include <linux/highmem.h>
 #include <linux/mm.h>
 #include <linux/kernel_stat.h>

@@ -696,6 +697,7 @@ void blk_set_queue_dying(struct request_queue *q)
         * prevent I/O from crossing blk_queue_enter().
         */
        blk_freeze_queue_start(q);
+       blk_pm_runtime_unlock(q);

        if (q->mq_ops)
                blk_mq_wake_waiters(q);

@@ -756,6 +758,7 @@ void blk_cleanup_queue(struct request_queue *q)
         * prevent that q->request_fn() gets invoked after draining finished.
         */
        blk_freeze_queue(q);
+       blk_pm_runtime_unlock(q);
        spin_lock_irq(lock);
        queue_flag_set(QUEUE_FLAG_DEAD, q);
        spin_unlock_irq(lock);

@@ -1045,6 +1048,8 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id,
 #ifdef CONFIG_BLK_DEV_IO_TRACE
        mutex_init(&q->blk_trace_mutex);
 #endif
+       blk_pm_init(q);
+
        mutex_init(&q->sysfs_lock);
        spin_lock_init(&q->__queue_lock);

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 8b23ae34d949..b1882a3a5216 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c

@@ -9,6 +9,7 @@
 #include <linux/backing-dev.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <linux/blk-pm.h>
 #include <linux/kmemleak.h>
 #include <linux/mm.h>
 #include <linux/init.h>

@@ -138,6 +139,7 @@ void blk_freeze_queue_start(struct request_queue *q)
 {
        int freeze_depth;

+       blk_pm_runtime_lock(q);
        freeze_depth = atomic_inc_return(&q->mq_freeze_depth);
        if (freeze_depth == 1) {
                percpu_ref_kill(&q->q_usage_counter);

@@ -201,6 +203,7 @@ void blk_mq_unfreeze_queue(struct request_queue *q)
                percpu_ref_reinit(&q->q_usage_counter);
                wake_up_all(&q->mq_freeze_wq);
        }
+       blk_pm_runtime_unlock(q);
 }