block: make struct elv_change_ctx private in elevator.c

[Christoph Hellwig <hch@xxxxxx>]

And add a helper for the nr_hw_queues update instead.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 block/blk-mq.c   | 23 ++---------------------
 block/blk.h      |  4 +---
 block/elevator.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
 block/elevator.h | 13 -------------
 4 files changed, 45 insertions(+), 39 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5c9f7391af92..61d3349b3bb3 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -4968,27 +4968,8 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
 		blk_mq_map_swqueue(q);
 	}
 
-	list_for_each_entry(q, &set->tag_list, tag_set_list) {
-		/*
-		 * nr_hw_queues is changed and elevator data depends on
-		 * it, so we have to force to rebuild elevator
-		 */
-		struct elv_change_ctx ctx = {
-			.name	= "none",
-			.force	= true,
-			.uevent	= true,
-		};
-		int ret = -ENODEV;
-
-		mutex_lock(&q->elevator_lock);
-		if (q->elevator && !blk_queue_dying(q))
-			ctx.name = q->elevator->type->elevator_name;
-		ret = __elevator_change(q, &ctx);
-		mutex_unlock(&q->elevator_lock);
-		blk_mq_unfreeze_queue_nomemrestore(q);
-		if (!ret)
-			WARN_ON_ONCE(elevator_change_done(q, &ctx));
-	}
+	list_for_each_entry(q, &set->tag_list, tag_set_list)
+		elv_update_nr_hw_queues(q);
 	memalloc_noio_restore(memflags);
 
 reregister:
diff --git a/block/blk.h b/block/blk.h
index 48cf6b1c36fe..6ba674d1ceba 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -12,7 +12,6 @@
 #include "blk-crypto-internal.h"
 
 struct elevator_type;
-struct elv_change_ctx;
 
 #define	BLK_DEV_MAX_SECTORS	(LLONG_MAX >> 9)
 #define	BLK_MIN_SEGMENT_SIZE	4096
@@ -320,10 +319,9 @@ bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
 
 bool blk_insert_flush(struct request *rq);
 
-int __elevator_change(struct request_queue *q, struct elv_change_ctx *ctx);
+void elv_update_nr_hw_queues(struct request_queue *q);
 void elevator_set_default(struct request_queue *q);
 void elevator_set_none(struct request_queue *q);
-int elevator_change_done(struct request_queue *q, struct elv_change_ctx *ctx);
 
 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
 		char *buf);
diff --git a/block/elevator.c b/block/elevator.c
index 378553fce5d8..71329a73bb44 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -53,6 +53,19 @@ static LIST_HEAD(elv_list);
  */
 #define rq_hash_key(rq)		(blk_rq_pos(rq) + blk_rq_sectors(rq))
 
+/* Holding context data for changing elevator */
+struct elv_change_ctx {
+	const char *name;
+	bool force;
+	bool uevent;
+	bool init;
+
+	/* for unregistering old elevator */
+	struct elevator_queue *old;
+	/* for registering new elevator */
+	struct elevator_queue *new;
+};
+
 static int elevator_change(struct request_queue *q,
 			   struct elv_change_ctx *ctx);
 
@@ -682,7 +695,8 @@ static void elevator_disable(struct request_queue *q,
 	blk_mq_unquiesce_queue(q);
 }
 
-int elevator_change_done(struct request_queue *q, struct elv_change_ctx *ctx)
+static int elevator_change_done(struct request_queue *q,
+		struct elv_change_ctx *ctx)
 {
 	int ret = 0;
 
@@ -712,7 +726,8 @@ int elevator_change_done(struct request_queue *q, struct elv_change_ctx *ctx)
 /*
  * Switch this queue to the given IO scheduler.
  */
-int __elevator_change(struct request_queue *q, struct elv_change_ctx *ctx)
+static int __elevator_change(struct request_queue *q,
+		struct elv_change_ctx *ctx)
 {
 	const char *elevator_name = ctx->name;
 	struct elevator_type *e;
@@ -740,6 +755,31 @@ int __elevator_change(struct request_queue *q, struct elv_change_ctx *ctx)
 	return ret;
 }
 
+/*
+ * The I/O scheduler depends on the number of hardware queues, this forces a
+ * reattachment when nr_hw_queues changes.
+ *
+ * Note that this unfreezes the passed in queue.
+ */
+void elv_update_nr_hw_queues(struct request_queue *q)
+{
+	struct elv_change_ctx ctx = {
+		.name	= "none",
+		.force	= true,
+		.uevent	= true,
+	};
+	int ret;
+
+	mutex_lock(&q->elevator_lock);
+	if (q->elevator && !blk_queue_dying(q))
+		ctx.name = q->elevator->type->elevator_name;
+	ret = __elevator_change(q, &ctx);
+	mutex_unlock(&q->elevator_lock);
+	blk_mq_unfreeze_queue_nomemrestore(q);
+	if (!ret)
+		WARN_ON_ONCE(elevator_change_done(q, &ctx));
+}
+
 static int elevator_change(struct request_queue *q,
 			   struct elv_change_ctx *ctx)
 {
diff --git a/block/elevator.h b/block/elevator.h
index b14c611c74b6..a07ce773a38f 100644
--- a/block/elevator.h
+++ b/block/elevator.h
@@ -124,19 +124,6 @@ struct elevator_queue
 #define ELEVATOR_FLAG_DYING		1
 #define ELEVATOR_FLAG_ENABLE_WBT_ON_EXIT	2
 
-/* Holding context data for changing elevator */
-struct elv_change_ctx {
-	const char *name;
-	bool force;
-	bool uevent;
-	bool init;
-
-	/* for unregistering old elevator */
-	struct elevator_queue *old;
-	/* for registering new elevator */
-	struct elevator_queue *new;
-};
-
 /*
  * block elevator interface
  */
-- 
2.47.2


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Content-Type: text/x-patch; charset=us-ascii
Content-Disposition: attachment; filename="0002-block-remove-__elevator_change.patch"