[PATCH v6 06/11] block: Modify revalidate zones

From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>,
	linux-block <linux-block@vger.kernel.org>,
	Damien Le Moal <Damien.LeMoal@wdc.com>,
	Keith Busch <kbusch@kernel.org>,
	"linux-scsi @ vger . kernel . org" <linux-scsi@vger.kernel.org>,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	"linux-fsdevel @ vger . kernel . org"
	<linux-fsdevel@vger.kernel.org>,
	Damien Le Moal <damien.lemoal@wdc.com>,
	Johannes Thumshirn <johannes.thumshirn@wdc.com>
Subject: [PATCH v6 06/11] block: Modify revalidate zones
Date: Wed, 15 Apr 2020 18:05:08 +0900	[thread overview]
Message-ID: <20200415090513.5133-7-johannes.thumshirn@wdc.com> (raw)
In-Reply-To: <20200415090513.5133-1-johannes.thumshirn@wdc.com>

From: Damien Le Moal <damien.lemoal@wdc.com>

Modify the interface of blk_revalidate_disk_zones() to add an optional
driver callback function that a driver can use to extend processing
done during zone revalidation. The callback, if defined, is executed
with the device request queue frozen, after all zones have been
inspected.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 block/blk-zoned.c              | 8 +++++++-
 drivers/block/null_blk_zoned.c | 2 +-
 include/linux/blkdev.h         | 3 ++-
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index c822cfa7a102..2912e964d7b2 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -471,14 +471,18 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx,
 /**
  * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
  * @disk:	Target disk
+ * @driver_cb:	LLD callback
  *
  * Helper function for low-level device drivers to (re) allocate and initialize
  * a disk request queue zone bitmaps. This functions should normally be called
  * within the disk ->revalidate method for blk-mq based drivers.  For BIO based
  * drivers only q->nr_zones needs to be updated so that the sysfs exposed value
  * is correct.
+ * If the @driver_cb callback function is not NULL, the callback is executed
+ * with the device request queue frozen after all zones have been checked.
  */
-int blk_revalidate_disk_zones(struct gendisk *disk)
+int blk_revalidate_disk_zones(struct gendisk *disk,
+			      void (*driver_cb)(struct gendisk *disk))
 {
 	struct request_queue *q = disk->queue;
 	struct blk_revalidate_zone_args args = {
@@ -512,6 +516,8 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
 		q->nr_zones = args.nr_zones;
 		swap(q->seq_zones_wlock, args.seq_zones_wlock);
 		swap(q->conv_zones_bitmap, args.conv_zones_bitmap);
+		if (driver_cb)
+			driver_cb(disk);
 		ret = 0;
 	} else {
 		pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index 9e4bcdad1a80..46641df2e58e 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -73,7 +73,7 @@ int null_register_zoned_dev(struct nullb *nullb)
 	struct request_queue *q = nullb->q;
 
 	if (queue_is_mq(q))
-		return blk_revalidate_disk_zones(nullb->disk);
+		return blk_revalidate_disk_zones(nullb->disk, NULL);
 
 	blk_queue_chunk_sectors(q, nullb->dev->zone_size_sects);
 	q->nr_zones = blkdev_nr_zones(nullb->disk);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0797d1e81802..62fe9f962478 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -362,7 +362,8 @@ unsigned int blkdev_nr_zones(struct gendisk *disk);
 extern int blkdev_zone_mgmt(struct block_device *bdev, enum req_opf op,
 			    sector_t sectors, sector_t nr_sectors,
 			    gfp_t gfp_mask);
-extern int blk_revalidate_disk_zones(struct gendisk *disk);
+int blk_revalidate_disk_zones(struct gendisk *disk,
+			      void (*driver_cb)(struct gendisk *disk));
 
 extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
 				     unsigned int cmd, unsigned long arg);
-- 
2.24.1

