[PATCH v3 1/5] nvme: factor namespace-head queue-limit update

[Yao Sang <sangyao@kylinos.cn>]

Move the namespace-head queue-limit update out of nvme_update_ns_info().
The update is self-contained, and moving it into a separate helper makes
the namespace scan easier to follow.

There is no behavior change.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yao Sang <sangyao@kylinos.cn>
---
 drivers/nvme/host/core.c | 103 +++++++++++++++++++++------------------
 1 file changed, 55 insertions(+), 48 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 1322c678f4eb..8e2b44ed4366 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2538,6 +2538,59 @@ static void nvme_stack_zone_resources(struct queue_limits *t,
 		min_not_zero(t->max_active_zones, b->max_active_zones);
 }
 
+static int nvme_update_ns_head_limits(struct nvme_ns *ns,
+		struct nvme_ns_info *info, bool unsupported)
+{
+	struct queue_limits *ns_lim = &ns->disk->queue->limits;
+	struct request_queue *head_q = ns->head->disk->queue;
+	struct queue_limits lim;
+	unsigned int memflags;
+	int ret;
+
+	lim = queue_limits_start_update(head_q);
+	memflags = blk_mq_freeze_queue(head_q);
+	/*
+	 * queue_limits mixes hardware limitations for bio splitting with device
+	 * configuration.
+	 *
+	 * For NVMe the device configuration can change after e.g. a Format
+	 * command, and we really want to pick up the new format value here. But
+	 * we must still stack the queue limits to the least common denominator
+	 * for multipathing to split the bios properly.
+	 *
+	 * To work around this, we explicitly set the device configuration to
+	 * those that we just queried, but only stack the splitting limits in to
+	 * make sure we still obey possibly lower limitations of other
+	 * controllers.
+	 */
+	lim.logical_block_size = ns_lim->logical_block_size;
+	lim.physical_block_size = ns_lim->physical_block_size;
+	lim.io_min = ns_lim->io_min;
+	lim.io_opt = ns_lim->io_opt;
+	queue_limits_stack_bdev(&lim, ns->disk->part0, 0,
+				ns->head->disk->disk_name);
+	if (lim.features & BLK_FEAT_ZONED)
+		nvme_stack_zone_resources(&lim, ns_lim);
+	if (unsupported)
+		ns->head->disk->flags |= GENHD_FL_HIDDEN;
+	else
+		nvme_init_integrity(ns->head, &lim, info);
+	lim.max_write_streams = ns_lim->max_write_streams;
+	lim.write_stream_granularity = ns_lim->write_stream_granularity;
+	ret = queue_limits_commit_update(head_q, &lim);
+	if (ret)
+		goto unfreeze_head_queue;
+
+	set_capacity_and_notify(ns->head->disk, get_capacity(ns->disk));
+	set_disk_ro(ns->head->disk, nvme_ns_is_readonly(ns, info));
+	nvme_mpath_revalidate_paths(ns->head);
+	ret = nvme_mpath_revalidate_zones(ns->head);
+
+unfreeze_head_queue:
+	blk_mq_unfreeze_queue(head_q, memflags);
+	return ret;
+}
+
 static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_ns_info *info)
 {
 	bool unsupported = false;
@@ -2576,54 +2629,8 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_ns_info *info)
 		ret = 0;
 	}
 
-	if (!ret && nvme_ns_head_multipath(ns->head)) {
-		struct queue_limits *ns_lim = &ns->disk->queue->limits;
-		struct queue_limits lim;
-		unsigned int memflags;
-
-		lim = queue_limits_start_update(ns->head->disk->queue);
-		memflags = blk_mq_freeze_queue(ns->head->disk->queue);
-		/*
-		 * queue_limits mixes values that are the hardware limitations
-		 * for bio splitting with what is the device configuration.
-		 *
-		 * For NVMe the device configuration can change after e.g. a
-		 * Format command, and we really want to pick up the new format
-		 * value here.  But we must still stack the queue limits to the
-		 * least common denominator for multipathing to split the bios
-		 * properly.
-		 *
-		 * To work around this, we explicitly set the device
-		 * configuration to those that we just queried, but only stack
-		 * the splitting limits in to make sure we still obey possibly
-		 * lower limitations of other controllers.
-		 */
-		lim.logical_block_size = ns_lim->logical_block_size;
-		lim.physical_block_size = ns_lim->physical_block_size;
-		lim.io_min = ns_lim->io_min;
-		lim.io_opt = ns_lim->io_opt;
-		queue_limits_stack_bdev(&lim, ns->disk->part0, 0,
-					ns->head->disk->disk_name);
-		if (lim.features & BLK_FEAT_ZONED)
-			nvme_stack_zone_resources(&lim, ns_lim);
-		if (unsupported)
-			ns->head->disk->flags |= GENHD_FL_HIDDEN;
-		else
-			nvme_init_integrity(ns->head, &lim, info);
-		lim.max_write_streams = ns_lim->max_write_streams;
-		lim.write_stream_granularity = ns_lim->write_stream_granularity;
-		ret = queue_limits_commit_update(ns->head->disk->queue, &lim);
-		if (ret)
-			goto unfreeze_head_queue;
-
-		set_capacity_and_notify(ns->head->disk, get_capacity(ns->disk));
-		set_disk_ro(ns->head->disk, nvme_ns_is_readonly(ns, info));
-		nvme_mpath_revalidate_paths(ns->head);
-		ret = nvme_mpath_revalidate_zones(ns->head);
-
-unfreeze_head_queue:
-		blk_mq_unfreeze_queue(ns->head->disk->queue, memflags);
-	}
+	if (!ret && nvme_ns_head_multipath(ns->head))
+		ret = nvme_update_ns_head_limits(ns, info, unsupported);
 
 	return ret;
 }
-- 
2.25.1