2 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index db29928de467..15d1aa53d96c 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -70,6 +70,8 @@ struct blk_mq_hw_ctx {
         struct dentry           *sched_debugfs_dir;
 #endif
 
+        struct list_head        hctx_list;
+
         /* Must be the last member - see also blk_mq_hw_ctx_size(). */
         struct srcu_struct      srcu[0];
 };
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index bd3e3f09bfa0..1aafeb923e7b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -535,6 +535,13 @@ struct request_queue {
 
         struct mutex            sysfs_lock;
 
+        /*
+         * for reusing dead hctx instance in case of updating
+         * nr_hw_queues
+         */
+        struct list_head        unused_hctx_list;
+        spinlock_t              unused_hctx_lock;
+
         atomic_t                mq_freeze_depth;
 
 #if defined(CONFIG_BLK_DEV_BSG)