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

Commit Message

Johannes Thumshirn April 15, 2020, 9:05 a.m. UTC

From: Damien Le Moal <[e-mail]>

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 <[e-mail]>
Signed-off-by: Johannes Thumshirn <[e-mail]>
---
 block/blk-zoned.c              | 8 +++++++-
 drivers/block/null_blk_zoned.c | 2 +-
 include/linux/blkdev.h         | 3 ++-
 3 files changed, 10 insertions(+), 3 deletions(-)

Comments

Christoph Hellwig April 16, 2020, 12:41 p.m. UTC | #1

On Wed, Apr 15, 2020 at 06:05:08PM +0900, Johannes Thumshirn wrote:
>   * @disk:	Target disk
> + * @driver_cb:	LLD callback

FYI, I find the name driver_cb and the description not very useful.  Of
course it is a driver callback, because the driver calls this function.
But the name and description don't explain at all what the callback is
supposed to do.

Except for the naming this looks fine.

Patch

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);