Merge branch 'linux-linaro-lsk-v4.9' into linux-linaro-lsk-v4.9-rtlinux-linaro-lsk-v4.9-rt-test

1 files changed, 8 insertions, 3 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 82500641f37b..e0a804ab5420 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1285,13 +1285,13 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 
 	blk_queue_bounce(q, &bio);
 
+	blk_queue_split(q, &bio, q->bio_split);
+
 	if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
 		bio_io_error(bio);
 		return BLK_QC_T_NONE;
 	}
 
-	blk_queue_split(q, &bio, q->bio_split);
-
 	if (!is_flush_fua && !blk_queue_nomerges(q) &&
 	    blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
 		return BLK_QC_T_NONE;
@@ -1612,7 +1612,8 @@ static void blk_mq_exit_hctx(struct request_queue *q,
 {
 	unsigned flush_start_tag = set->queue_depth;
 
-	blk_mq_tag_idle(hctx);
+	if (blk_mq_hw_queue_mapped(hctx))
+		blk_mq_tag_idle(hctx);
 
 	if (set->ops->exit_request)
 		set->ops->exit_request(set->driver_data,
@@ -1927,6 +1928,9 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
 	struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx;
 
 	blk_mq_sysfs_unregister(q);
+
+	/* protect against switching io scheduler  */
+	mutex_lock(&q->sysfs_lock);
 	for (i = 0; i < set->nr_hw_queues; i++) {
 		int node;
 
@@ -1976,6 +1980,7 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
 		}
 	}
 	q->nr_hw_queues = i;
+	mutex_unlock(&q->sysfs_lock);
 	blk_mq_sysfs_register(q);
 }