[PATCH 17/23] usb-storage: switch to using ->device_configure

[Christoph Hellwig <hch@lst.de>]

Switch to the ->device_configure method instead of ->slave_configure
and update the block limits on the passed in queue_limits instead
of using the per-limit accessors.

Also use the proper atomic queue limit update helpers and freeze the
queue when updating max_hw_sectors from sysfs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/usb/storage/scsiglue.c | 36 ++++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index eb4ba03e082d89..b31464740f6c86 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -82,7 +82,7 @@ static int slave_alloc (struct scsi_device *sdev)
 	return 0;
 }
 
-static int slave_configure(struct scsi_device *sdev)
+static int device_configure(struct scsi_device *sdev, struct queue_limits *lim)
 {
 	struct us_data *us = host_to_us(sdev->host);
 	struct device *dev = us->pusb_dev->bus->sysdev;
@@ -97,31 +97,28 @@ static int slave_configure(struct scsi_device *sdev)
 
 		if (us->fflags & US_FL_MAX_SECTORS_MIN)
 			max_sectors = PAGE_SIZE >> 9;
-		if (queue_max_hw_sectors(sdev->request_queue) > max_sectors)
-			blk_queue_max_hw_sectors(sdev->request_queue,
-					      max_sectors);
+		lim->max_hw_sectors = min(lim->max_hw_sectors, max_sectors);
 	} else if (sdev->type == TYPE_TAPE) {
 		/*
 		 * Tapes need much higher max_sector limits, so just
 		 * raise it to the maximum possible (4 GB / 512) and
 		 * let the queue segment size sort out the real limit.
 		 */
-		blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF);
+		lim->max_hw_sectors = 0x7FFFFF;
 	} else if (us->pusb_dev->speed >= USB_SPEED_SUPER) {
 		/*
 		 * USB3 devices will be limited to 2048 sectors. This gives us
 		 * better throughput on most devices.
 		 */
-		blk_queue_max_hw_sectors(sdev->request_queue, 2048);
+		lim->max_hw_sectors = 2048;
 	}
 
 	/*
 	 * The max_hw_sectors should be up to maximum size of a mapping for
 	 * the device. Otherwise, a DMA API might fail on swiotlb environment.
 	 */
-	blk_queue_max_hw_sectors(sdev->request_queue,
-		min_t(size_t, queue_max_hw_sectors(sdev->request_queue),
-		      dma_max_mapping_size(dev) >> SECTOR_SHIFT));
+	lim->max_hw_sectors = min_t(size_t,
+		lim->max_hw_sectors, dma_max_mapping_size(dev) >> SECTOR_SHIFT);
 
 	/*
 	 * We can't put these settings in slave_alloc() because that gets
@@ -582,13 +579,22 @@ static ssize_t max_sectors_store(struct device *dev, struct device_attribute *at
 		size_t count)
 {
 	struct scsi_device *sdev = to_scsi_device(dev);
+	struct queue_limits lim;
 	unsigned short ms;
+	int ret;
 
-	if (sscanf(buf, "%hu", &ms) > 0) {
-		blk_queue_max_hw_sectors(sdev->request_queue, ms);
-		return count;
-	}
-	return -EINVAL;
+	if (sscanf(buf, "%hu", &ms) <= 0)
+		return -EINVAL;
+
+	blk_mq_freeze_queue(sdev->request_queue);
+	lim = queue_limits_start_update(sdev->request_queue);
+	lim.max_hw_sectors = ms;
+	ret = queue_limits_commit_update(sdev->request_queue, &lim);
+	blk_mq_unfreeze_queue(sdev->request_queue);
+
+	if (ret)
+		return ret;
+	return count;
 }
 static DEVICE_ATTR_RW(max_sectors);
 
@@ -626,7 +632,7 @@ static const struct scsi_host_template usb_stor_host_template = {
 	.this_id =			-1,
 
 	.slave_alloc =			slave_alloc,
-	.slave_configure =		slave_configure,
+	.device_configure =		device_configure,
 	.target_alloc =			target_alloc,
 
 	/* lots of sg segments can be handled */
-- 
2.39.2