Re: [PATCH 5/8] block: replace seq_zones_bitmap with conv_zones_bitmap

From: "Javier González" <javier@javigon.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>,
	Damien Le Moal <Damien.LeMoal@wdc.com>,
	Hans Holmberg <hans@owltronix.com>,
	linux-block@vger.kernel.org
Subject: Re: [PATCH 5/8] block: replace seq_zones_bitmap with conv_zones_bitmap
Date: Tue, 3 Dec 2019 15:02:39 +0100	[thread overview]
Message-ID: <20191203140239.x5a5ll2u5wgou6la@mpHalley.local> (raw)
In-Reply-To: <20191203093908.24612-6-hch@lst.de>

On 03.12.2019 10:39, Christoph Hellwig wrote:
>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.
>
>Signed-off-by: Christoph Hellwig <hch@lst.de>
>---
> block/blk-zoned.c      | 18 +++++++++---------
> include/linux/blkdev.h | 14 ++++++++------
> 2 files changed, 17 insertions(+), 15 deletions(-)
>
>diff --git a/block/blk-zoned.c b/block/blk-zoned.c
>index 65a9bdc9fe27..9c3931051f4f 100644
>--- a/block/blk-zoned.c
>+++ b/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);
>diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
>index c5852de402b6..503c4d4c5884 100644
>--- a/include/linux/blkdev.h
>+++ b/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)
>-- 
>2.20.1
>

Looks good to me.

Reviewed-by: Javier González <javier@javigon.com>