From 70ab0b2d51f84fc7d9eb6ed81c3986595efaa33d Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@fb.com>
Date: Thu, 24 Apr 2014 08:50:38 -0600
Subject: Revert "blk-mq: initialize req->q in allocation"

This reverts commit 6a3c8a3ac0e68dcfc2a01f4aa1ca0edd1a1701eb.

We need selective clearing of the request to make the init-at-free
time completely safe. Otherwise we end up stomping on
rq->atomic_flags, which we don't want to do.
---
 block/blk-mq.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index cea1bd87a416..7d5650d75aef 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -82,6 +82,7 @@ static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx,
 	tag = blk_mq_get_tag(hctx->tags, gfp, reserved);
 	if (tag != BLK_MQ_TAG_FAIL) {
 		rq = hctx->tags->rqs[tag];
+		blk_rq_init(hctx->queue, rq);
 		rq->tag = tag;
 
 		return rq;
@@ -186,7 +187,6 @@ static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
 	if (blk_queue_io_stat(q))
 		rw_flags |= REQ_IO_STAT;
 
-	rq->q = q;
 	rq->mq_ctx = ctx;
 	rq->cmd_flags = rw_flags;
 	rq->start_time = jiffies;
@@ -258,7 +258,6 @@ static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
 	const int tag = rq->tag;
 	struct request_queue *q = rq->q;
 
-	blk_rq_init(hctx->queue, rq);
 	blk_mq_put_tag(hctx->tags, tag);
 	blk_mq_queue_exit(q);
 }
@@ -1195,7 +1194,6 @@ static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
 		left -= to_do * rq_size;
 		for (j = 0; j < to_do; j++) {
 			tags->rqs[i] = p;
-			blk_rq_init(NULL, tags->rqs[i]);
 			if (set->ops->init_request) {
 				if (set->ops->init_request(set->driver_data,
 						tags->rqs[i], hctx_idx, i,
-- 
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