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From: Damien Le Moal <dlemoal@kernel.org>
To: linux-block@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
	linux-scsi@vger.kernel.org,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	dm-devel@lists.linux.dev, Mike Snitzer <snitzer@redhat.com>,
	linux-nvme@lists.infradead.org, Keith Busch <kbusch@kernel.org>,
	Christoph Hellwig <hch@lst.de>
Subject: [PATCH v7 11/28] block: Allow BIO-based drivers to use blk_revalidate_disk_zones()
Date: Mon,  8 Apr 2024 10:41:11 +0900	[thread overview]
Message-ID: <20240408014128.205141-12-dlemoal@kernel.org> (raw)
In-Reply-To: <20240408014128.205141-1-dlemoal@kernel.org>

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: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 block/blk-zoned.c | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index a60ac5b3e637..da0fc7e2d00a 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -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;
-- 
2.44.0


  parent reply	other threads:[~2024-04-08  1:41 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-08  1:41 [PATCH v7 00/28] Zone write plugging Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 01/28] block: Restore sector of flush requests Damien Le Moal
2024-04-08 15:42   ` Johannes Thumshirn
2024-04-08  1:41 ` [PATCH v7 02/28] block: Remove req_bio_endio() Damien Le Moal
2024-04-08 15:46   ` Johannes Thumshirn
2024-04-08  1:41 ` [PATCH v7 03/28] block: Introduce blk_zone_update_request_bio() Damien Le Moal
2024-04-08 15:47   ` Johannes Thumshirn
2024-04-08  1:41 ` [PATCH v7 04/28] block: Introduce bio_straddles_zones() and bio_offset_from_zone_start() Damien Le Moal
2024-04-08 15:50   ` Johannes Thumshirn
2024-04-08  1:41 ` [PATCH v7 05/28] block: Allow using bio_attempt_back_merge() internally Damien Le Moal
2024-04-08 15:51   ` Johannes Thumshirn
2024-04-08  1:41 ` [PATCH v7 06/28] block: Remember zone capacity when revalidating zones Damien Le Moal
2024-04-08 15:53   ` Johannes Thumshirn
2024-04-08  1:41 ` [PATCH v7 07/28] block: Introduce zone write plugging Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 08/28] block: Fake max open zones limit when there is no limit Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 09/28] block: Allow zero value of max_zone_append_sectors queue limit Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 10/28] block: Implement zone append emulation Damien Le Moal
2024-04-08  1:41 ` Damien Le Moal [this message]
2024-04-08  1:41 ` [PATCH v7 12/28] dm: Use the block layer " Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 13/28] scsi: sd: " Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 14/28] ublk_drv: Do not request ELEVATOR_F_ZBD_SEQ_WRITE elevator feature Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 15/28] null_blk: " Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 16/28] null_blk: Introduce zone_append_max_sectors attribute Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 17/28] null_blk: Introduce fua attribute Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 18/28] nvmet: zns: Do not reference the gendisk conv_zones_bitmap Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 19/28] block: Remove BLK_STS_ZONE_RESOURCE Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 20/28] block: Simplify blk_revalidate_disk_zones() interface Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 21/28] block: mq-deadline: Remove support for zone write locking Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 22/28] block: Remove elevator required features Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 23/28] block: Do not check zone type in blk_check_zone_append() Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 24/28] block: Move zone related debugfs attribute to blk-zoned.c Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 25/28] block: Replace zone_wlock debugfs entry with zone_wplugs entry Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 26/28] block: Remove zone write locking Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 27/28] block: Do not force select mq-deadline with CONFIG_BLK_DEV_ZONED Damien Le Moal
2024-04-08  1:41 ` [PATCH v7 28/28] block: Do not special-case plugging of zone write operations Damien Le Moal
2024-04-08  6:02 ` [PATCH v7 00/28] Zone write plugging Christoph Hellwig
2024-04-12  0:19 ` Damien Le Moal
2024-04-17 14:45 ` Jens Axboe

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