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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 6/8] block: allocate the zone bitmaps lazily
Date: Tue, 3 Dec 2019 15:03:48 +0100	[thread overview]
Message-ID: <20191203140348.str5nt7oudu2prpn@mpHalley.local> (raw)
In-Reply-To: <20191203093908.24612-7-hch@lst.de>

On 03.12.2019 10:39, Christoph Hellwig wrote:
>Allocate the conventional zone bitmap and the sequential zone locking
>bitmap only when we find a zone of the respective type.  This avoids
>wasting memory on the conventional zone bitmap for devices that only
>have sequential zones, and will also prepare for other future changes.
>
>Signed-off-by: Christoph Hellwig <hch@lst.de>
>---
> block/blk-zoned.c | 65 +++++++++++++++++++++++------------------------
> 1 file changed, 32 insertions(+), 33 deletions(-)
>
>diff --git a/block/blk-zoned.c b/block/blk-zoned.c
>index 9c3931051f4f..0131f9e14bd1 100644
>--- a/block/blk-zoned.c
>+++ b/block/blk-zoned.c
>@@ -342,6 +342,7 @@ struct blk_revalidate_zone_args {
> 	struct gendisk	*disk;
> 	unsigned long	*conv_zones_bitmap;
> 	unsigned long	*seq_zones_wlock;
>+	unsigned int	nr_zones;
> 	sector_t	sector;
> };
>
>@@ -385,8 +386,22 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
> 	/* Check zone type */
> 	switch (zone->type) {
> 	case BLK_ZONE_TYPE_CONVENTIONAL:
>+		if (!args->conv_zones_bitmap) {
>+			args->conv_zones_bitmap =
>+				blk_alloc_zone_bitmap(q->node, args->nr_zones);
>+			if (!args->conv_zones_bitmap)
>+				return -ENOMEM;
>+		}
>+		set_bit(idx, args->conv_zones_bitmap);
>+		break;
> 	case BLK_ZONE_TYPE_SEQWRITE_REQ:
> 	case BLK_ZONE_TYPE_SEQWRITE_PREF:
>+		if (!args->seq_zones_wlock) {
>+			args->seq_zones_wlock =
>+				blk_alloc_zone_bitmap(q->node, args->nr_zones);
>+			if (!args->seq_zones_wlock)
>+				return -ENOMEM;
>+		}
> 		break;
> 	default:
> 		pr_warn("%s: Invalid zone type 0x%x at sectors %llu\n",
>@@ -394,37 +409,10 @@ 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->conv_zones_bitmap);
>-
> 	args->sector += zone->len;
> 	return 0;
> }
>
>-static int blk_update_zone_info(struct gendisk *disk, unsigned int nr_zones,
>-				struct blk_revalidate_zone_args *args)
>-{
>-	/*
>-	 * Ensure that all memory allocations in this context are done as
>-	 * if GFP_NOIO was specified.
>-	 */
>-	unsigned int noio_flag = memalloc_noio_save();
>-	struct request_queue *q = disk->queue;
>-	int ret;
>-
>-	args->seq_zones_wlock = blk_alloc_zone_bitmap(q->node, nr_zones);
>-	if (!args->seq_zones_wlock)
>-		return -ENOMEM;
>-	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,
>-				       blk_revalidate_zone_cb, args);
>-	memalloc_noio_restore(noio_flag);
>-	return ret;
>-}
>-
> /**
>  * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
>  * @disk:	Target disk
>@@ -437,8 +425,10 @@ static int blk_update_zone_info(struct gendisk *disk, unsigned int nr_zones,
> int blk_revalidate_disk_zones(struct gendisk *disk)
> {
> 	struct request_queue *q = disk->queue;
>-	unsigned int nr_zones = blkdev_nr_zones(disk);
>-	struct blk_revalidate_zone_args args = { .disk = disk };
>+	struct blk_revalidate_zone_args args = {
>+		.disk		= disk,
>+		.nr_zones	= blkdev_nr_zones(disk),
>+	};
> 	int ret = 0;
>
> 	if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
>@@ -449,12 +439,21 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
> 	 * needs to be updated so that the sysfs exposed value is correct.
> 	 */
> 	if (!queue_is_mq(q)) {
>-		q->nr_zones = nr_zones;
>+		q->nr_zones = args.nr_zones;
> 		return 0;
> 	}
>
>-	if (nr_zones)
>-		ret = blk_update_zone_info(disk, nr_zones, &args);
>+	/*
>+	 * Ensure that all memory allocations in this context are done as
>+	 * if GFP_NOIO was specified.
>+	 */
>+	if (args.nr_zones) {
>+		unsigned int noio_flag = memalloc_noio_save();
>+
>+		ret = disk->fops->report_zones(disk, 0, args.nr_zones,
>+					       blk_revalidate_zone_cb, &args);
>+		memalloc_noio_restore(noio_flag);
>+	}
>
> 	/*
> 	 * Install the new bitmaps, making sure the queue is stopped and
>@@ -463,7 +462,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
> 	 */
> 	blk_mq_freeze_queue(q);
> 	if (ret >= 0) {
>-		q->nr_zones = nr_zones;
>+		q->nr_zones = args.nr_zones;
> 		swap(q->seq_zones_wlock, args.seq_zones_wlock);
> 		swap(q->conv_zones_bitmap, args.conv_zones_bitmap);
> 		ret = 0;
>-- 
>2.20.1

Looks good to me.

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

  reply	other threads:[~2019-12-03 14:03 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-03  9:39 avoid out of bounds zone bitmap access Christoph Hellwig
2019-12-03  9:39 ` [PATCH 1/8] null_blk: fix zone size paramter check Christoph Hellwig
2019-12-03  9:39 ` [PATCH 2/8] null_blk: cleanup null_gendisk_register Christoph Hellwig
2019-12-03  9:39 ` [PATCH 3/8] block: remove the empty line at the end of blk-zoned.c Christoph Hellwig
2019-12-03  9:39 ` [PATCH 4/8] block: simplify blkdev_nr_zones Christoph Hellwig
2019-12-03  9:39 ` [PATCH 5/8] block: replace seq_zones_bitmap with conv_zones_bitmap Christoph Hellwig
2019-12-03 14:02   ` Javier González
2019-12-03  9:39 ` [PATCH 6/8] block: allocate the zone bitmaps lazily Christoph Hellwig
2019-12-03 14:03   ` Javier González [this message]
2019-12-03  9:39 ` [PATCH 7/8] block: don't handle bio based drivers in blk_revalidate_disk_zones Christoph Hellwig
2019-12-03 14:04   ` Javier González
2019-12-03  9:39 ` [PATCH 8/8] block: set the zone size in blk_revalidate_disk_zones atomically Christoph Hellwig
2019-12-03 14:00   ` Javier González
2019-12-03 15:18     ` Christoph Hellwig
2019-12-03 15:34       ` Javier González
2019-12-03 15:42         ` Christoph Hellwig
2019-12-03 17:17           ` Javier González
2019-12-03 16:00 ` avoid out of bounds zone bitmap access Jens Axboe

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