dm: Call dm_revalidate_zones() after setting the queue limits

dm_revalidate_zones() is called from dm_set_zone_restrictions() when the
mapped device queue limits are not yet set. However,
dm_revalidate_zones() calls blk_revalidate_disk_zones() and this
function consults and modifies the mapped device queue limits. Thus,
currently, blk_revalidate_disk_zones() operates on limits that are not
yet initialized.

Fix this by moving the call to dm_revalidate_zones() out of
dm_set_zone_restrictions() and into dm_table_set_restrictions() after
executing queue_limits_set().

To further cleanup dm_set_zones_restrictions(), the message about the
type of zone append (native or emulated) is also moved inside
dm_revalidate_zones().

Fixes: 1c0e720 ("dm: use queue_limits_set")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Link: https://lore.kernel.org/r/20240611023639.89277-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: damien-lemoal

drivers/md/dm-table.c

@@ -1921,10 +1921,7 @@ int 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
-	 * and resources necessary for zone append emulation if necessary.
-	 */
+	/* For a zoned table, setup the zone related queue attributes. */
 	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && limits->zoned) {
 		r = dm_set_zones_restrictions(t, q, limits);
 		if (r)
@@ -1935,6 +1932,16 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 	if (r)
 		return r;
 
+	/*
+	 * Now that the limits are set, check the zones mapped by the table
+	 * and setup the resources for zone append emulation if necessary.
+	 */
+	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && limits->zoned) {
+		r = dm_revalidate_zones(t, q);
+		if (r)
+			return r;
+	}
+
 	dm_update_crypto_profile(q, t);
 
 	/*

drivers/md/dm-zone.c

@@ -166,14 +166,22 @@ static int dm_check_zoned_cb(struct blk_zone *zone, unsigned int idx,
  * blk_revalidate_disk_zones() function here as the mapped device is suspended
  * (this is called from __bind() context).
  */
-static int dm_revalidate_zones(struct mapped_device *md, struct dm_table *t)
+int dm_revalidate_zones(struct dm_table *t, struct request_queue *q)
 {
+	struct mapped_device *md = t->md;
 	struct gendisk *disk = md->disk;
 	int ret;
 
+	if (!get_capacity(disk))
+		return 0;
+
 	/* Revalidate only if something changed. */
-	if (!disk->nr_zones || disk->nr_zones != md->nr_zones)
+	if (!disk->nr_zones || disk->nr_zones != md->nr_zones) {
+		DMINFO("%s using %s zone append",
+		       disk->disk_name,
+		       queue_emulates_zone_append(q) ? "emulated" : "native");
 		md->nr_zones = 0;
+	}
 
 	if (md->nr_zones)
 		return 0;
@@ -240,9 +248,6 @@ int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q,
 		lim->max_zone_append_sectors = 0;
 	}
 
-	if (!get_capacity(md->disk))
-		return 0;
-
 	/*
 	 * Count conventional zones to check that the mapped device will indeed 
 	 * have sequential write required zones.
@@ -269,16 +274,6 @@ int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q,
 		return 0;
 	}
 
-	if (!md->disk->nr_zones) {
-		DMINFO("%s using %s zone append",
-		       md->disk->disk_name,
-		       queue_emulates_zone_append(q) ? "emulated" : "native");
-	}
-
-	ret = dm_revalidate_zones(md, t);
-	if (ret < 0)
-		return ret;
-
 	if (!static_key_enabled(&zoned_enabled.key))
 		static_branch_enable(&zoned_enabled);
 	return 0;

drivers/md/dm.h

@@ -103,6 +103,7 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
  */
 int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q,
 		struct queue_limits *lim);
+int dm_revalidate_zones(struct dm_table *t, struct request_queue *q);
 void dm_zone_endio(struct dm_io *io, struct bio *clone);
 #ifdef CONFIG_BLK_DEV_ZONED
 int dm_blk_report_zones(struct gendisk *disk, sector_t sector,