dm: move zone related code to dm-zone.c

Move core and table code used for zoned targets and conditionally
defined with #ifdef CONFIG_BLK_DEV_ZONED to the new file dm-zone.c.
This file is conditionally compiled depending on CONFIG_BLK_DEV_ZONED.
The small helper dm_set_zones_restrictions() is introduced to
initialize a mapped device request queue zone attributes in
dm_table_set_restrictions().

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/Makefile

@@ -92,6 +92,10 @@ ifeq ($(CONFIG_DM_UEVENT),y)
 dm-mod-objs			+= dm-uevent.o
 endif
 
+ifeq ($(CONFIG_BLK_DEV_ZONED),y)
+dm-mod-objs			+= dm-zone.o
+endif
+
 ifeq ($(CONFIG_DM_VERITY_FEC),y)
 dm-verity-objs			+= dm-verity-fec.o
 endif

drivers/md/dm-table.c

@@ -2064,17 +2064,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	    dm_table_any_dev_attr(t, device_is_not_random, NULL))
 		blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
 
-	/*
+	/* For a zoned target, setup the zones related queue attributes */
-	 * For a zoned target, the number of zones should be updated for the
+	if (blk_queue_is_zoned(q))
-	 * correct value to be exposed in sysfs queue/nr_zones. For a BIO based
+		dm_set_zones_restrictions(t, q);
-	 * target, this is all that is needed.
-	 */
-#ifdef CONFIG_BLK_DEV_ZONED
-	if (blk_queue_is_zoned(q)) {
-		WARN_ON_ONCE(queue_is_mq(q));
-		q->nr_zones = blkdev_nr_zones(t->md->disk);
-	}
-#endif
 
 	dm_update_keyslot_manager(q, t);
 	blk_queue_update_readahead(q);

drivers/md/dm-zone.c

@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ */
+
+#include <linux/blkdev.h>
+
+#include "dm-core.h"
+
+/*
+ * User facing dm device block device report zone operation. This calls the
+ * report_zones operation for each target of a device table. This operation is
+ * generally implemented by targets using dm_report_zones().
+ */
+int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
+			unsigned int nr_zones, report_zones_cb cb, void *data)
+{
+	struct mapped_device *md = disk->private_data;
+	struct dm_table *map;
+	int srcu_idx, ret;
+	struct dm_report_zones_args args = {
+		.next_sector = sector,
+		.orig_data = data,
+		.orig_cb = cb,
+	};
+
+	if (dm_suspended_md(md))
+		return -EAGAIN;
+
+	map = dm_get_live_table(md, &srcu_idx);
+	if (!map) {
+		ret = -EIO;
+		goto out;
+	}
+
+	do {
+		struct dm_target *tgt;
+
+		tgt = dm_table_find_target(map, args.next_sector);
+		if (WARN_ON_ONCE(!tgt->type->report_zones)) {
+			ret = -EIO;
+			goto out;
+		}
+
+		args.tgt = tgt;
+		ret = tgt->type->report_zones(tgt, &args,
+					      nr_zones - args.zone_idx);
+		if (ret < 0)
+			goto out;
+	} while (args.zone_idx < nr_zones &&
+		 args.next_sector < get_capacity(disk));
+
+	ret = args.zone_idx;
+out:
+	dm_put_live_table(md, srcu_idx);
+	return ret;
+}
+
+int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx, void *data)
+{
+	struct dm_report_zones_args *args = data;
+	sector_t sector_diff = args->tgt->begin - args->start;
+
+	/*
+	 * Ignore zones beyond the target range.
+	 */
+	if (zone->start >= args->start + args->tgt->len)
+		return 0;
+
+	/*
+	 * Remap the start sector and write pointer position of the zone
+	 * to match its position in the target range.
+	 */
+	zone->start += sector_diff;
+	if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
+		if (zone->cond == BLK_ZONE_COND_FULL)
+			zone->wp = zone->start + zone->len;
+		else if (zone->cond == BLK_ZONE_COND_EMPTY)
+			zone->wp = zone->start;
+		else
+			zone->wp += sector_diff;
+	}
+
+	args->next_sector = zone->start + zone->len;
+	return args->orig_cb(zone, args->zone_idx++, args->orig_data);
+}
+EXPORT_SYMBOL_GPL(dm_report_zones_cb);
+
+void dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q)
+{
+	if (!blk_queue_is_zoned(q))
+		return;
+
+	/*
+	 * For a zoned target, the number of zones should be updated for the
+	 * correct value to be exposed in sysfs queue/nr_zones. For a BIO based
+	 * target, this is all that is needed.
+	 */
+	WARN_ON_ONCE(queue_is_mq(q));
+	q->nr_zones = blkdev_nr_zones(t->md->disk);
+}

drivers/md/dm.c

@@ -444,84 +444,6 @@ static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return dm_get_geometry(md, geo);
 }
 
-#ifdef CONFIG_BLK_DEV_ZONED
-int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx, void *data)
-{
-	struct dm_report_zones_args *args = data;
-	sector_t sector_diff = args->tgt->begin - args->start;
-
-	/*
-	 * Ignore zones beyond the target range.
-	 */
-	if (zone->start >= args->start + args->tgt->len)
-		return 0;
-
-	/*
-	 * Remap the start sector and write pointer position of the zone
-	 * to match its position in the target range.
-	 */
-	zone->start += sector_diff;
-	if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
-		if (zone->cond == BLK_ZONE_COND_FULL)
-			zone->wp = zone->start + zone->len;
-		else if (zone->cond == BLK_ZONE_COND_EMPTY)
-			zone->wp = zone->start;
-		else
-			zone->wp += sector_diff;
-	}
-
-	args->next_sector = zone->start + zone->len;
-	return args->orig_cb(zone, args->zone_idx++, args->orig_data);
-}
-EXPORT_SYMBOL_GPL(dm_report_zones_cb);
-
-static int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
-		unsigned int nr_zones, report_zones_cb cb, void *data)
-{
-	struct mapped_device *md = disk->private_data;
-	struct dm_table *map;
-	int srcu_idx, ret;
-	struct dm_report_zones_args args = {
-		.next_sector = sector,
-		.orig_data = data,
-		.orig_cb = cb,
-	};
-
-	if (dm_suspended_md(md))
-		return -EAGAIN;
-
-	map = dm_get_live_table(md, &srcu_idx);
-	if (!map) {
-		ret = -EIO;
-		goto out;
-	}
-
-	do {
-		struct dm_target *tgt;
-
-		tgt = dm_table_find_target(map, args.next_sector);
-		if (WARN_ON_ONCE(!tgt->type->report_zones)) {
-			ret = -EIO;
-			goto out;
-		}
-
-		args.tgt = tgt;
-		ret = tgt->type->report_zones(tgt, &args,
-					      nr_zones - args.zone_idx);
-		if (ret < 0)
-			goto out;
-	} while (args.zone_idx < nr_zones &&
-		 args.next_sector < get_capacity(disk));
-
-	ret = args.zone_idx;
-out:
-	dm_put_live_table(md, srcu_idx);
-	return ret;
-}
-#else
-#define dm_blk_report_zones		NULL
-#endif /* CONFIG_BLK_DEV_ZONED */
-
 static int dm_prepare_ioctl(struct mapped_device *md, int *srcu_idx,
 			    struct block_device **bdev)
 {

drivers/md/dm.h

@@ -100,6 +100,17 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
  */
 #define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
 
+/*
+ * Zoned targets related functions.
+ */
+void dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q);
+#ifdef CONFIG_BLK_DEV_ZONED
+int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
+			unsigned int nr_zones, report_zones_cb cb, void *data);
+#else
+#define dm_blk_report_zones	NULL
+#endif
+
 /*-----------------------------------------------------------------
  * A registry of target types.
  *---------------------------------------------------------------*/