Commit 946dd71e authored by Damien Le Moal's avatar Damien Le Moal Committed by Jens Axboe
Browse files

block: Allow BIO-based drivers to use blk_revalidate_disk_zones() 



In preparation for allowing BIO based device drivers to use zone write
plugging and its zone append emulation, allow these drivers to call
blk_revalidate_disk_zones() so that all zone resources necessary to zone
write plugging can be initialized.

To do so, remove the check in blk_revalidate_disk_zones() restricting
the use of this function to mq request-based drivers to allow also
BIO-based drivers to use it. This is safe to do as long as the
BIO-based block device queue is already setup and usable, as it should,
and can be safely frozen.

The helper function disk_need_zone_resources() is added to control the
allocation and initialization of the zone write plug hash table and
of the conventional zone bitmap only for mq devices and for BIO-based
devices that require zone append emulation.

Signed-off-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Tested-by: default avatarHans Holmberg <hans.holmberg@wdc.com>
Tested-by: default avatarDennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-12-dlemoal@kernel.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 9b1ce7f0

block/blk-zoned.c

+24 −6
Original line number Diff line number Diff line
@@ -1512,12 +1512,28 @@ void disk_free_zone_resources(struct gendisk *disk) 
	disk->nr_zones = 0;

}



static inline bool disk_need_zone_resources(struct gendisk *disk)

{

	/*

	 * All mq zoned devices need zone resources so that the block layer

	 * can automatically handle write BIO plugging. BIO-based device drivers

	 * (e.g. DM devices) are normally responsible for handling zone write

	 * ordering and do not need zone resources, unless the driver requires

	 * zone append emulation.

	 */

	return queue_is_mq(disk->queue) ||

		queue_emulates_zone_append(disk->queue);

}



static int disk_revalidate_zone_resources(struct gendisk *disk,

					  unsigned int nr_zones)

{

	struct queue_limits *lim = &disk->queue->limits;

	unsigned int pool_size;



	if (!disk_need_zone_resources(disk))

		return 0;



	/*

	 * If the device has no limit on the maximum number of open and active

	 * zones, use BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE.
@@ -1635,6 +1651,9 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx, 
				disk->disk_name);

			return -ENODEV;

		}



		if (!disk_need_zone_resources(disk))

			break;

		if (!args->conv_zones_bitmap) {

			args->conv_zones_bitmap =

				blk_alloc_zone_bitmap(q->node, args->nr_zones);
@@ -1666,10 +1685,11 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx, 
		/*

		 * We need to track the write pointer of all zones that are not

		 * empty nor full. So make sure we have a zone write plug for

		 * such zone.

		 * such zone if the device has a zone write plug hash table.

		 */

		wp_offset = blk_zone_wp_offset(zone);

		if (wp_offset && wp_offset < zone_sectors) {

		if (disk->zone_wplugs_hash &&

		    wp_offset && wp_offset < zone_sectors) {

			zwplug = disk_get_and_lock_zone_wplug(disk, zone->start,

							      GFP_NOIO, &flags);

			if (!zwplug)
@@ -1700,8 +1720,8 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx, 
 * be called within the disk ->revalidate method for blk-mq based drivers.

 * Before calling this function, the device driver must already have set the

 * device zone size (chunk_sector limit) and the max zone append limit.

 * For BIO based drivers, this function cannot be used. BIO based device drivers

 * only need to set disk->nr_zones so that the sysfs exposed value is correct.

 * BIO based drivers can also use this function as long as the device queue

 * can be safely frozen.

 * If the @update_driver_data callback function is not NULL, the callback is

 * executed with the device request queue frozen after all zones have been

 * checked.
@@ -1718,8 +1738,6 @@ int blk_revalidate_disk_zones(struct gendisk *disk, 


	if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))

		return -EIO;

	if (WARN_ON_ONCE(!queue_is_mq(q)))

		return -EIO;



	if (!capacity)

		return -ENODEV;