block: Simplify blk_revalidate_disk_zones() interface

The only user of blk_revalidate_disk_zones() second argument was the
SCSI disk driver (sd). Now that this driver does not require this
update_driver_data argument, remove it to simplify the interface of
blk_revalidate_disk_zones(). Also update the function kdoc comment to
be more accurate (i.e. there is no gendisk ->revalidate method).

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-21-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: damien-lemoal

block/blk-zoned.c

@@ -1713,21 +1713,17 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
 /**
  * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
  * @disk:	Target disk
- * @update_driver_data:	Callback to update driver data on the frozen disk
  *
- * Helper function for low-level device drivers to check and (re) allocate and
- * initialize a disk request queue zone bitmaps. This functions should normally
- * be called within the disk ->revalidate method for blk-mq based drivers.
+ * Helper function for low-level device drivers to check, (re) allocate and
+ * initialize resources used for managing zoned disks. This function should
+ * normally be called by blk-mq based drivers when a zoned gendisk is probed
+ * and when the zone configuration of the gendisk changes (e.g. after a format).
  * Before calling this function, the device driver must already have set the
  * device zone size (chunk_sector limit) and the max zone append limit.
  * BIO based drivers can also use this function as long as the device queue
  * can be safely frozen.
- * If the @update_driver_data callback function is not NULL, the callback is
- * executed with the device request queue frozen after all zones have been
- * checked.
  */
-int blk_revalidate_disk_zones(struct gendisk *disk,
-			      void (*update_driver_data)(struct gendisk *disk))
+int blk_revalidate_disk_zones(struct gendisk *disk)
 {
 	struct request_queue *q = disk->queue;
 	sector_t zone_sectors = q->limits.chunk_sectors;
@@ -1794,13 +1790,10 @@ int blk_revalidate_disk_zones(struct gendisk *disk,
 	 * referencing the bitmaps).
 	 */
 	blk_mq_freeze_queue(q);
-	if (ret > 0) {
+	if (ret > 0)
 		ret = disk_update_zone_resources(disk, &args);
-		if (update_driver_data)
-			update_driver_data(disk);
-	} else {
+	else
 		pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
-	}
 	if (ret)
 		disk_free_zone_resources(disk);
 	blk_mq_unfreeze_queue(q);

drivers/block/null_blk/zoned.c

@@ -177,7 +177,7 @@ int null_register_zoned_dev(struct nullb *nullb)
 		disk->disk_name,
 		queue_emulates_zone_append(q) ? "emulated" : "native");
 
-	return blk_revalidate_disk_zones(disk, NULL);
+	return blk_revalidate_disk_zones(disk);
 }
 
 void null_free_zoned_dev(struct nullb_device *dev)

drivers/block/ublk_drv.c

@@ -221,7 +221,7 @@ static int ublk_get_nr_zones(const struct ublk_device *ub)
 
 static int ublk_revalidate_disk_zones(struct ublk_device *ub)
 {
-	return blk_revalidate_disk_zones(ub->ub_disk, NULL);
+	return blk_revalidate_disk_zones(ub->ub_disk);
 }
 
 static int ublk_dev_param_zoned_validate(const struct ublk_device *ub)

drivers/block/virtio_blk.c

@@ -1543,7 +1543,7 @@ static int virtblk_probe(struct virtio_device *vdev)
 	 */
 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && lim.zoned) {
 		blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, vblk->disk->queue);
-		err = blk_revalidate_disk_zones(vblk->disk, NULL);
+		err = blk_revalidate_disk_zones(vblk->disk);
 		if (err)
 			goto out_cleanup_disk;
 	}

drivers/md/dm-zone.c

@@ -169,7 +169,7 @@ static int dm_revalidate_zones(struct mapped_device *md, struct dm_table *t)
 	 * our table for dm_blk_report_zones() to use directly.
 	 */
 	md->zone_revalidate_map = t;
-	ret = blk_revalidate_disk_zones(disk, NULL);
+	ret = blk_revalidate_disk_zones(disk);
 	md->zone_revalidate_map = NULL;
 
 	if (ret) {

drivers/nvme/host/core.c

@@ -2150,7 +2150,7 @@ static int nvme_update_ns_info_block(struct nvme_ns *ns,
 	blk_mq_unfreeze_queue(ns->disk->queue);
 
 	if (blk_queue_is_zoned(ns->queue)) {
-		ret = blk_revalidate_disk_zones(ns->disk, NULL);
+		ret = blk_revalidate_disk_zones(ns->disk);
 		if (ret && !nvme_first_scan(ns->disk))
 			goto out;
 	}

drivers/scsi/sd_zbc.c

@@ -572,7 +572,7 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
 	blk_queue_max_zone_append_sectors(q, 0);
 
 	flags = memalloc_noio_save();
-	ret = blk_revalidate_disk_zones(disk, NULL);
+	ret = blk_revalidate_disk_zones(disk);
 	memalloc_noio_restore(flags);
 	if (ret) {
 		sdkp->zone_info = (struct zoned_disk_info){ };

include/linux/blkdev.h

@@ -336,8 +336,7 @@ int blkdev_report_zones(struct block_device *bdev, sector_t sector,
 		unsigned int nr_zones, report_zones_cb cb, void *data);
 int blkdev_zone_mgmt(struct block_device *bdev, enum req_op op,
 		sector_t sectors, sector_t nr_sectors);
-int blk_revalidate_disk_zones(struct gendisk *disk,
-		void (*update_driver_data)(struct gendisk *disk));
+int blk_revalidate_disk_zones(struct gendisk *disk);
 
 /*
  * Independent access ranges: struct blk_independent_access_range describes