[PATCH 4/8] Revert "blk-mq: Introduce atomic variants of blk_mq_(all_tag|tagset_busy)_iter"

[Ming Lei <ming.lei@redhat.com>]

This reverts commit 5d39098af969f222253036b1b2e7ffc57c734570.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 block/blk-mq-tag.c        | 38 +++++---------------------------------
 block/blk-mq-tag.h        |  2 +-
 block/blk-mq.c            |  2 +-
 drivers/scsi/hosts.c      | 16 ++++++++--------
 drivers/scsi/ufs/ufshcd.c |  4 ++--
 include/linux/blk-mq.h    |  2 --
 6 files changed, 17 insertions(+), 47 deletions(-)

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index d8eaa38a1bd1..2a37731e8244 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -322,19 +322,18 @@ static void __blk_mq_all_tag_iter(struct blk_mq_tags *tags,
 }
 
 /**
- * blk_mq_all_tag_iter_atomic - iterate over all requests in a tag map
+ * blk_mq_all_tag_iter - iterate over all requests in a tag map
  * @tags:	Tag map to iterate over.
  * @fn:		Pointer to the function that will be called for each
  *		request. @fn will be called as follows: @fn(rq, @priv,
  *		reserved) where rq is a pointer to a request. 'reserved'
  *		indicates whether or not @rq is a reserved request. Return
- *		true to continue iterating tags, false to stop. Must not
- *		sleep.
+ *		true to continue iterating tags, false to stop.
  * @priv:	Will be passed as second argument to @fn.
  *
- * Does not sleep.
+ * Caller has to pass the tag map from which requests are allocated.
  */
-void blk_mq_all_tag_iter_atomic(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
+void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
 		void *priv)
 {
 	__blk_mq_all_tag_iter(tags, fn, priv, BT_TAG_ITER_STATIC_RQS);
@@ -349,8 +348,6 @@ void blk_mq_all_tag_iter_atomic(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
  *		indicates whether or not @rq is a reserved request. Return
  *		true to continue iterating tags, false to stop.
  * @priv:	Will be passed as second argument to @fn.
- *
- * May sleep.
  */
 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
 		busy_tag_iter_fn *fn, void *priv)
@@ -365,31 +362,6 @@ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
 }
 EXPORT_SYMBOL(blk_mq_tagset_busy_iter);
 
-/**
- * blk_mq_tagset_busy_iter_atomic - iterate over all started requests in a tag set
- * @tagset:	Tag set to iterate over.
- * @fn:		Pointer to the function that will be called for each started
- *		request. @fn will be called as follows: @fn(rq, @priv,
- *		reserved) where rq is a pointer to a request. 'reserved'
- *		indicates whether or not @rq is a reserved request. Return
- *		true to continue iterating tags, false to stop. Must not sleep.
- * @priv:	Will be passed as second argument to @fn.
- *
- * Does not sleep.
- */
-void blk_mq_tagset_busy_iter_atomic(struct blk_mq_tag_set *tagset,
-		busy_tag_iter_fn *fn, void *priv)
-{
-	int i;
-
-	for (i = 0; i < tagset->nr_hw_queues; i++) {
-		if (tagset->tags && tagset->tags[i])
-			__blk_mq_all_tag_iter(tagset->tags[i], fn, priv,
-					      BT_TAG_ITER_STARTED);
-	}
-}
-EXPORT_SYMBOL(blk_mq_tagset_busy_iter_atomic);
-
 static bool blk_mq_tagset_count_completed_rqs(struct request *rq,
 		void *data, bool reserved)
 {
@@ -412,7 +384,7 @@ void blk_mq_tagset_wait_completed_request(struct blk_mq_tag_set *tagset)
 	while (true) {
 		unsigned count = 0;
 
-		blk_mq_tagset_busy_iter_atomic(tagset,
+		blk_mq_tagset_busy_iter(tagset,
 				blk_mq_tagset_count_completed_rqs, &count);
 		if (!count)
 			break;
diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 0290c308ece9..7d3e6b333a4a 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -43,7 +43,7 @@ extern void blk_mq_tag_resize_shared_sbitmap(struct blk_mq_tag_set *set,
 extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool);
 void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
 		void *priv);
-void blk_mq_all_tag_iter_atomic(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
+void blk_mq_all_tag_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
 		void *priv);
 
 static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 79c01b1f885c..927189a55575 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2484,7 +2484,7 @@ static bool blk_mq_hctx_has_requests(struct blk_mq_hw_ctx *hctx)
 		.hctx	= hctx,
 	};
 
-	blk_mq_all_tag_iter_atomic(tags, blk_mq_has_request, &data);
+	blk_mq_all_tag_iter(tags, blk_mq_has_request, &data);
 	return data.has_rq;
 }
 
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index f8863aa88642..697c09ef259b 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -573,8 +573,8 @@ int scsi_host_busy(struct Scsi_Host *shost)
 {
 	int cnt = 0;
 
-	blk_mq_tagset_busy_iter_atomic(&shost->tag_set,
-				       scsi_host_check_in_flight, &cnt);
+	blk_mq_tagset_busy_iter(&shost->tag_set,
+				scsi_host_check_in_flight, &cnt);
 	return cnt;
 }
 EXPORT_SYMBOL(scsi_host_busy);
@@ -672,8 +672,8 @@ static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
  */
 void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status)
 {
-	blk_mq_tagset_busy_iter_atomic(&shost->tag_set, complete_all_cmds_iter,
-				       &status);
+	blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
+				&status);
 }
 EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
 
@@ -694,11 +694,11 @@ static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
 /**
  * scsi_host_busy_iter - Iterate over all busy commands
  * @shost:	Pointer to Scsi_Host.
- * @fn:		Function to call on each busy command. Must not sleep.
+ * @fn:		Function to call on each busy command
  * @priv:	Data pointer passed to @fn
  *
  * If locking against concurrent command completions is required
- * it has to be provided by the caller.
+ * ithas to be provided by the caller
  **/
 void scsi_host_busy_iter(struct Scsi_Host *shost,
 			 bool (*fn)(struct scsi_cmnd *, void *, bool),
@@ -709,7 +709,7 @@ void scsi_host_busy_iter(struct Scsi_Host *shost,
 		.priv = priv,
 	};
 
-	blk_mq_tagset_busy_iter_atomic(&shost->tag_set,
-				       __scsi_host_busy_iter_fn, &iter_data);
+	blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
+				&iter_data);
 }
 EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 6d2f8f18e2a3..c86760788c72 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1380,7 +1380,7 @@ static bool ufshcd_any_tag_in_use(struct ufs_hba *hba)
 	struct request_queue *q = hba->cmd_queue;
 	int busy = 0;
 
-	blk_mq_tagset_busy_iter_atomic(q->tag_set, ufshcd_is_busy, &busy);
+	blk_mq_tagset_busy_iter(q->tag_set, ufshcd_is_busy, &busy);
 	return busy;
 }
 
@@ -6269,7 +6269,7 @@ static irqreturn_t ufshcd_tmc_handler(struct ufs_hba *hba)
 		.pending = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL),
 	};
 
-	blk_mq_tagset_busy_iter_atomic(q->tag_set, ufshcd_compl_tm, &ci);
+	blk_mq_tagset_busy_iter(q->tag_set, ufshcd_compl_tm, &ci);
 	return ci.ncpl ? IRQ_HANDLED : IRQ_NONE;
 }
 
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index dfa0114a49fd..2c473c9b8990 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -526,8 +526,6 @@ void blk_mq_run_hw_queues(struct request_queue *q, bool async);
 void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs);
 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
 		busy_tag_iter_fn *fn, void *priv);
-void blk_mq_tagset_busy_iter_atomic(struct blk_mq_tag_set *tagset,
-		busy_tag_iter_fn *fn, void *priv);
 void blk_mq_tagset_wait_completed_request(struct blk_mq_tag_set *tagset);
 void blk_mq_freeze_queue(struct request_queue *q);
 void blk_mq_unfreeze_queue(struct request_queue *q);
-- 
2.29.2