1 files changed, 42 insertions, 46 deletions

diff --git a/block/blk-flush.c b/block/blk-flush.c
index 8220517c2d67..43d6152897a4 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -95,26 +95,9 @@ static void blk_kick_flush(struct request_queue *q,
 			   struct blk_flush_queue *fq, blk_opf_t flags);
 
 static inline struct blk_flush_queue *
-blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
+blk_get_flush_queue(struct blk_mq_ctx *ctx)
 {
-	return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
-}
-
-static unsigned int blk_flush_policy(unsigned long fflags, struct request *rq)
-{
-	unsigned int policy = 0;
-
-	if (blk_rq_sectors(rq))
-		policy |= REQ_FSEQ_DATA;
-
-	if (fflags & (1UL << QUEUE_FLAG_WC)) {
-		if (rq->cmd_flags & REQ_PREFLUSH)
-			policy |= REQ_FSEQ_PREFLUSH;
-		if (!(fflags & (1UL << QUEUE_FLAG_FUA)) &&
-		    (rq->cmd_flags & REQ_FUA))
-			policy |= REQ_FSEQ_POSTFLUSH;
-	}
-	return policy;
+	return blk_mq_map_queue(REQ_OP_FLUSH, ctx)->fq;
 }
 
 static unsigned int blk_flush_cur_seq(struct request *rq)
@@ -130,6 +113,8 @@ static void blk_flush_restore_request(struct request *rq)
 	 * original @rq->bio.  Restore it.
 	 */
 	rq->bio = rq->biotail;
+	if (rq->bio)
+		rq->__sector = rq->bio->bi_iter.bi_sector;
 
 	/* make @rq a normal request */
 	rq->rq_flags &= ~RQF_FLUSH_SEQ;
@@ -143,7 +128,7 @@ static void blk_account_io_flush(struct request *rq)
 	part_stat_lock();
 	part_stat_inc(part, ios[STAT_FLUSH]);
 	part_stat_add(part, nsecs[STAT_FLUSH],
-		      ktime_get_ns() - rq->start_time_ns);
+		      blk_time_get_ns() - rq->start_time_ns);
 	part_stat_unlock();
 }
 
@@ -183,13 +168,13 @@ static void blk_flush_complete_seq(struct request *rq,
 		/* queue for flush */
 		if (list_empty(pending))
 			fq->flush_pending_since = jiffies;
-		list_move_tail(&rq->flush.list, pending);
+		list_add_tail(&rq->queuelist, pending);
 		break;
 
 	case REQ_FSEQ_DATA:
-		list_move_tail(&rq->flush.list, &fq->flush_data_in_flight);
+		fq->flush_data_in_flight++;
 		spin_lock(&q->requeue_lock);
-		list_add(&rq->queuelist, &q->requeue_list);
+		list_move(&rq->queuelist, &q->requeue_list);
 		spin_unlock(&q->requeue_lock);
 		blk_mq_kick_requeue_list(q);
 		break;
@@ -201,7 +186,7 @@ static void blk_flush_complete_seq(struct request *rq,
 		 * flush data request completion path.  Restore @rq for
 		 * normal completion and end it.
 		 */
-		list_del_init(&rq->flush.list);
+		list_del_init(&rq->queuelist);
 		blk_flush_restore_request(rq);
 		blk_mq_end_request(rq, error);
 		break;
@@ -220,7 +205,7 @@ static enum rq_end_io_ret flush_end_io(struct request *flush_rq,
 	struct list_head *running;
 	struct request *rq, *n;
 	unsigned long flags = 0;
-	struct blk_flush_queue *fq = blk_get_flush_queue(q, flush_rq->mq_ctx);
+	struct blk_flush_queue *fq = blk_get_flush_queue(flush_rq->mq_ctx);
 
 	/* release the tag's ownership to the req cloned from */
 	spin_lock_irqsave(&fq->mq_flush_lock, flags);
@@ -257,10 +242,11 @@ static enum rq_end_io_ret flush_end_io(struct request *flush_rq,
 	fq->flush_running_idx ^= 1;
 
 	/* and push the waiting requests to the next stage */
-	list_for_each_entry_safe(rq, n, running, flush.list) {
+	list_for_each_entry_safe(rq, n, running, queuelist) {
 		unsigned int seq = blk_flush_cur_seq(rq);
 
 		BUG_ON(seq != REQ_FSEQ_PREFLUSH && seq != REQ_FSEQ_POSTFLUSH);
+		list_del_init(&rq->queuelist);
 		blk_flush_complete_seq(rq, fq, seq, error);
 	}
 
@@ -291,7 +277,7 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq,
 {
 	struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx];
 	struct request *first_rq =
-		list_first_entry(pending, struct request, flush.list);
+		list_first_entry(pending, struct request, queuelist);
 	struct request *flush_rq = fq->flush_rq;
 
 	/* C1 described at the top of this file */
@@ -299,7 +285,7 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq,
 		return;
 
 	/* C2 and C3 */
-	if (!list_empty(&fq->flush_data_in_flight) &&
+	if (fq->flush_data_in_flight &&
 	    time_before(jiffies,
 			fq->flush_pending_since + FLUSH_PENDING_TIMEOUT))
 		return;
@@ -323,16 +309,9 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq,
 	flush_rq->mq_ctx = first_rq->mq_ctx;
 	flush_rq->mq_hctx = first_rq->mq_hctx;
 
-	if (!q->elevator) {
+	if (!q->elevator)
 		flush_rq->tag = first_rq->tag;
-
-		/*
-		 * We borrow data request's driver tag, so have to mark
-		 * this flush request as INFLIGHT for avoiding double
-		 * account of this driver tag
-		 */
-		flush_rq->rq_flags |= RQF_MQ_INFLIGHT;
-	} else
+	else
 		flush_rq->internal_tag = first_rq->internal_tag;
 
 	flush_rq->cmd_flags = REQ_OP_FLUSH | REQ_PREFLUSH;
@@ -362,7 +341,7 @@ static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq,
 	struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
 	struct blk_mq_ctx *ctx = rq->mq_ctx;
 	unsigned long flags;
-	struct blk_flush_queue *fq = blk_get_flush_queue(q, ctx);
+	struct blk_flush_queue *fq = blk_get_flush_queue(ctx);
 
 	if (q->elevator) {
 		WARN_ON(rq->tag < 0);
@@ -374,6 +353,12 @@ static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq,
 	 * the comment in flush_end_io().
 	 */
 	spin_lock_irqsave(&fq->mq_flush_lock, flags);
+	fq->flush_data_in_flight--;
+	/*
+	 * May have been corrupted by rq->rq_next reuse, we need to
+	 * re-initialize rq->queuelist before reusing it here.
+	 */
+	INIT_LIST_HEAD(&rq->queuelist);
 	blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error);
 	spin_unlock_irqrestore(&fq->mq_flush_lock, flags);
 
@@ -384,7 +369,6 @@ static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq,
 static void blk_rq_init_flush(struct request *rq)
 {
 	rq->flush.seq = 0;
-	INIT_LIST_HEAD(&rq->flush.list);
 	rq->rq_flags |= RQF_FLUSH_SEQ;
 	rq->flush.saved_end_io = rq->end_io; /* Usually NULL */
 	rq->end_io = mq_flush_data_end_io;
@@ -398,19 +382,32 @@ static void blk_rq_init_flush(struct request *rq)
 bool blk_insert_flush(struct request *rq)
 {
 	struct request_queue *q = rq->q;
-	unsigned long fflags = q->queue_flags;	/* may change, cache */
-	unsigned int policy = blk_flush_policy(fflags, rq);
-	struct blk_flush_queue *fq = blk_get_flush_queue(q, rq->mq_ctx);
+	struct blk_flush_queue *fq = blk_get_flush_queue(rq->mq_ctx);
+	bool supports_fua = q->limits.features & BLK_FEAT_FUA;
+	unsigned int policy = 0;
 
 	/* FLUSH/FUA request must never be merged */
 	WARN_ON_ONCE(rq->bio != rq->biotail);
 
+	if (blk_rq_sectors(rq))
+		policy |= REQ_FSEQ_DATA;
+
+	/*
+	 * Check which flushes we need to sequence for this operation.
+	 */
+	if (blk_queue_write_cache(q)) {
+		if (rq->cmd_flags & REQ_PREFLUSH)
+			policy |= REQ_FSEQ_PREFLUSH;
+		if ((rq->cmd_flags & REQ_FUA) && !supports_fua)
+			policy |= REQ_FSEQ_POSTFLUSH;
+	}
+
 	/*
 	 * @policy now records what operations need to be done.  Adjust
 	 * REQ_PREFLUSH and FUA for the driver.
 	 */
 	rq->cmd_flags &= ~REQ_PREFLUSH;
-	if (!(fflags & (1UL << QUEUE_FLAG_FUA)))
+	if (!supports_fua)
 		rq->cmd_flags &= ~REQ_FUA;
 
 	/*
@@ -443,9 +440,9 @@ bool blk_insert_flush(struct request *rq)
 		 * the post flush, and then just pass the command on.
 		 */
 		blk_rq_init_flush(rq);
-		rq->flush.seq |= REQ_FSEQ_POSTFLUSH;
+		rq->flush.seq |= REQ_FSEQ_PREFLUSH;
 		spin_lock_irq(&fq->mq_flush_lock);
-		list_move_tail(&rq->flush.list, &fq->flush_data_in_flight);
+		fq->flush_data_in_flight++;
 		spin_unlock_irq(&fq->mq_flush_lock);
 		return false;
 	default:
@@ -496,7 +493,6 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
 
 	INIT_LIST_HEAD(&fq->flush_queue[0]);
 	INIT_LIST_HEAD(&fq->flush_queue[1]);
-	INIT_LIST_HEAD(&fq->flush_data_in_flight);
 
 	return fq;