block: replace seq_zones_bitmap with conv_zones_bitmap

Invert the meaning of seq_zones_bitmap by keeping a bitmap of
conventional zones.  This allows not having a bitmap for devices
that do not have conventional zones.
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-zoned.c

@@ -332,15 +332,15 @@ static inline unsigned long *blk_alloc_zone_bitmap(int node,
 
 void blk_queue_free_zone_bitmaps(struct request_queue *q)
 {
-	kfree(q->seq_zones_bitmap);
-	q->seq_zones_bitmap = NULL;
+	kfree(q->conv_zones_bitmap);
+	q->conv_zones_bitmap = NULL;
 	kfree(q->seq_zones_wlock);
 	q->seq_zones_wlock = NULL;
 }
 
 struct blk_revalidate_zone_args {
 	struct gendisk	*disk;
-	unsigned long	*seq_zones_bitmap;
+	unsigned long	*conv_zones_bitmap;
 	unsigned long	*seq_zones_wlock;
 	sector_t	sector;
 };
@@ -394,8 +394,8 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
 		return -ENODEV;
 	}
 
-	if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL)
-		set_bit(idx, args->seq_zones_bitmap);
+	if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
+		set_bit(idx, args->conv_zones_bitmap);
 
 	args->sector += zone->len;
 	return 0;
@@ -415,8 +415,8 @@ static int blk_update_zone_info(struct gendisk *disk, unsigned int nr_zones,
 	args->seq_zones_wlock = blk_alloc_zone_bitmap(q->node, nr_zones);
 	if (!args->seq_zones_wlock)
 		return -ENOMEM;
-	args->seq_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
-	if (!args->seq_zones_bitmap)
+	args->conv_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
+	if (!args->conv_zones_bitmap)
 		return -ENOMEM;
 
 	ret = disk->fops->report_zones(disk, 0, nr_zones,
@@ -465,7 +465,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
 	if (ret >= 0) {
 		q->nr_zones = nr_zones;
 		swap(q->seq_zones_wlock, args.seq_zones_wlock);
-		swap(q->seq_zones_bitmap, args.seq_zones_bitmap);
+		swap(q->conv_zones_bitmap, args.conv_zones_bitmap);
 		ret = 0;
 	} else {
 		pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
@@ -474,7 +474,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
 	blk_mq_unfreeze_queue(q);
 
 	kfree(args.seq_zones_wlock);
-	kfree(args.seq_zones_bitmap);
+	kfree(args.conv_zones_bitmap);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);

include/linux/blkdev.h

@@ -503,9 +503,9 @@ struct request_queue {
 	/*
 	 * Zoned block device information for request dispatch control.
 	 * nr_zones is the total number of zones of the device. This is always
-	 * 0 for regular block devices. seq_zones_bitmap is a bitmap of nr_zones
-	 * bits which indicates if a zone is conventional (bit clear) or
-	 * sequential (bit set). seq_zones_wlock is a bitmap of nr_zones
+	 * 0 for regular block devices. conv_zones_bitmap is a bitmap of nr_zones
+	 * bits which indicates if a zone is conventional (bit set) or
+	 * sequential (bit clear). seq_zones_wlock is a bitmap of nr_zones
 	 * bits which indicates if a zone is write locked, that is, if a write
 	 * request targeting the zone was dispatched. All three fields are
 	 * initialized by the low level device driver (e.g. scsi/sd.c).
@@ -518,7 +518,7 @@ struct request_queue {
 	 * blk_mq_unfreeze_queue().
 	 */
 	unsigned int		nr_zones;
-	unsigned long		*seq_zones_bitmap;
+	unsigned long		*conv_zones_bitmap;
 	unsigned long		*seq_zones_wlock;
 #endif /* CONFIG_BLK_DEV_ZONED */
 
@@ -723,9 +723,11 @@ static inline unsigned int blk_queue_zone_no(struct request_queue *q,
 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
 					 sector_t sector)
 {
-	if (!blk_queue_is_zoned(q) || !q->seq_zones_bitmap)
+	if (!blk_queue_is_zoned(q))
 		return false;
-	return test_bit(blk_queue_zone_no(q, sector), q->seq_zones_bitmap);
+	if (!q->conv_zones_bitmap)
+		return true;
+	return !test_bit(blk_queue_zone_no(q, sector), q->conv_zones_bitmap);
 }
 #else /* CONFIG_BLK_DEV_ZONED */
 static inline unsigned int blk_queue_nr_zones(struct request_queue *q)