Commit 29459c3e authored by Damien Le Moal's avatar Damien Le Moal Committed by Jens Axboe
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block: Fix zone write plugging handling of devices with a runt zone 



A zoned device may have a last sequential write required zone that is
smaller than other zones. However, all tests to check if a zone write
plug write offset exceeds the zone capacity use the same capacity
value stored in the gendisk zone_capacity field. This is incorrect for a
zoned device with a last runt (smaller) zone.

Add the new field last_zone_capacity to struct gendisk to store the
capacity of the last zone of the device. blk_revalidate_seq_zone() and
blk_revalidate_conv_zone() are both modified to get this value when
disk_zone_is_last() returns true. Similarly to zone_capacity, the value
is first stored using the last_zone_capacity field of struct
blk_revalidate_zone_args. Once zone revalidation of all zones is done,
this is used to set the gendisk last_zone_capacity field.

The checks to determine if a zone is full or if a sector offset in a
zone exceeds the zone capacity in disk_should_remove_zone_wplug(),
disk_zone_wplug_abort_unaligned(), blk_zone_write_plug_init_request(),
and blk_zone_wplug_prepare_bio() are modified to use the new helper
functions disk_zone_is_full() and disk_zone_wplug_is_full().
disk_zone_is_full() uses the zone index to determine if the zone being
tested is the last one of the disk and uses the either the disk
zone_capacity or last_zone_capacity accordingly.

Fixes: dd291d77 ("block: Introduce zone write plugging")
Signed-off-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Reviewed-by: default avatarNiklas Cassel <cassel@kernel.org>
Link: https://lore.kernel.org/r/20240530054035.491497-4-dlemoal@kernel.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent cd639993

block/blk-zoned.c

+27 −8
Original line number Diff line number Diff line
@@ -455,6 +455,20 @@ static bool disk_zone_is_last(struct gendisk *disk, struct blk_zone *zone) 
	return zone->start + zone->len >= get_capacity(disk);

}



static bool disk_zone_is_full(struct gendisk *disk,

			      unsigned int zno, unsigned int offset_in_zone)

{

	if (zno < disk->nr_zones - 1)

		return offset_in_zone >= disk->zone_capacity;

	return offset_in_zone >= disk->last_zone_capacity;

}



static bool disk_zone_wplug_is_full(struct gendisk *disk,

				    struct blk_zone_wplug *zwplug)

{

	return disk_zone_is_full(disk, zwplug->zone_no, zwplug->wp_offset);

}



static bool disk_insert_zone_wplug(struct gendisk *disk,

				   struct blk_zone_wplug *zwplug)

{
@@ -548,7 +562,7 @@ static inline bool disk_should_remove_zone_wplug(struct gendisk *disk, 
		return false;



	/* We can remove zone write plugs for zones that are empty or full. */

	return !zwplug->wp_offset || zwplug->wp_offset >= disk->zone_capacity;

	return !zwplug->wp_offset || disk_zone_wplug_is_full(disk, zwplug);

}



static void disk_remove_zone_wplug(struct gendisk *disk,
@@ -669,13 +683,12 @@ static void disk_zone_wplug_abort(struct blk_zone_wplug *zwplug) 
static void disk_zone_wplug_abort_unaligned(struct gendisk *disk,

					    struct blk_zone_wplug *zwplug)

{

	unsigned int zone_capacity = disk->zone_capacity;

	unsigned int wp_offset = zwplug->wp_offset;

	struct bio_list bl = BIO_EMPTY_LIST;

	struct bio *bio;



	while ((bio = bio_list_pop(&zwplug->bio_list))) {

		if (wp_offset >= zone_capacity ||

		if (disk_zone_is_full(disk, zwplug->zone_no, wp_offset) ||

		    (bio_op(bio) != REQ_OP_ZONE_APPEND &&

		     bio_offset_from_zone_start(bio) != wp_offset)) {

			blk_zone_wplug_bio_io_error(zwplug, bio);
@@ -914,7 +927,6 @@ void blk_zone_write_plug_init_request(struct request *req) 
	sector_t req_back_sector = blk_rq_pos(req) + blk_rq_sectors(req);

	struct request_queue *q = req->q;

	struct gendisk *disk = q->disk;

	unsigned int zone_capacity = disk->zone_capacity;

	struct blk_zone_wplug *zwplug =

		disk_get_zone_wplug(disk, blk_rq_pos(req));

	unsigned long flags;
@@ -938,7 +950,7 @@ void blk_zone_write_plug_init_request(struct request *req) 
	 * into the back of the request.

	 */

	spin_lock_irqsave(&zwplug->lock, flags);

	while (zwplug->wp_offset < zone_capacity) {

	while (!disk_zone_wplug_is_full(disk, zwplug)) {

		bio = bio_list_peek(&zwplug->bio_list);

		if (!bio)

			break;
@@ -984,7 +996,7 @@ static bool blk_zone_wplug_prepare_bio(struct blk_zone_wplug *zwplug, 
	 * We know such BIO will fail, and that would potentially overflow our

	 * write pointer offset beyond the end of the zone.

	 */

	if (zwplug->wp_offset >= disk->zone_capacity)

	if (disk_zone_wplug_is_full(disk, zwplug))

		goto err;



	if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
@@ -1561,6 +1573,7 @@ void disk_free_zone_resources(struct gendisk *disk) 
	kfree(disk->conv_zones_bitmap);

	disk->conv_zones_bitmap = NULL;

	disk->zone_capacity = 0;

	disk->last_zone_capacity = 0;

	disk->nr_zones = 0;

}
@@ -1605,6 +1618,7 @@ struct blk_revalidate_zone_args { 
	unsigned long	*conv_zones_bitmap;

	unsigned int	nr_zones;

	unsigned int	zone_capacity;

	unsigned int	last_zone_capacity;

	sector_t	sector;

};
@@ -1622,6 +1636,7 @@ static int disk_update_zone_resources(struct gendisk *disk, 


	disk->nr_zones = args->nr_zones;

	disk->zone_capacity = args->zone_capacity;

	disk->last_zone_capacity = args->last_zone_capacity;

	swap(disk->conv_zones_bitmap, args->conv_zones_bitmap);

	if (disk->conv_zones_bitmap)

		nr_conv_zones = bitmap_weight(disk->conv_zones_bitmap,
@@ -1673,6 +1688,9 @@ static int blk_revalidate_conv_zone(struct blk_zone *zone, unsigned int idx, 
		return -ENODEV;

	}



	if (disk_zone_is_last(disk, zone))

		args->last_zone_capacity = zone->capacity;



	if (!disk_need_zone_resources(disk))

		return 0;
@@ -1703,8 +1721,9 @@ static int blk_revalidate_seq_zone(struct blk_zone *zone, unsigned int idx, 
	 */

	if (!args->zone_capacity)

		args->zone_capacity = zone->capacity;

	if (!disk_zone_is_last(disk, zone) &&

	    zone->capacity != args->zone_capacity) {

	if (disk_zone_is_last(disk, zone)) {

		args->last_zone_capacity = zone->capacity;

	} else if (zone->capacity != args->zone_capacity) {

		pr_warn("%s: Invalid variable zone capacity\n",

			disk->disk_name);

		return -ENODEV;

include/linux/blkdev.h

+1 −0
Original line number Diff line number Diff line
@@ -186,6 +186,7 @@ struct gendisk { 
	 */

	unsigned int		nr_zones;

	unsigned int		zone_capacity;

	unsigned int		last_zone_capacity;

	unsigned long		*conv_zones_bitmap;

	unsigned int            zone_wplugs_hash_bits;

	spinlock_t              zone_wplugs_lock;