block: introduce disk_report_zone()

Commit b76b840fd933 ("dm: Fix dm-zoned-reclaim zone write pointer
alignment") introduced an indirect call for the callback function of a
report zones executed with blkdev_report_zones(). This is necessary so
that the function disk_zone_wplug_sync_wp_offset() can be called to
refresh a zone write plug zone write pointer offset after a write error.
However, this solution makes following the path of a zone information
harder to understand.

Clean this up by introducing the new blk_report_zones_args structure to
define a zone report callback and its private data and introduce the
helper function disk_report_zone() which calls both
disk_zone_wplug_sync_wp_offset() and the zone report user callback
function for all zones of a zone report. This helper function must be
called by all block device drivers that implement the report zones
block operation in order to correctly report a zone information.

All block device drivers supporting the report_zones block operation are
updated to use this new scheme.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 8 insertions, 2 deletions

diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 84fdc3a6a19a..38f625af6ab4 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -538,12 +538,18 @@ void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone);
 #ifdef CONFIG_BLK_DEV_ZONED
 struct dm_report_zones_args {
 	struct dm_target *tgt;
+	struct gendisk *disk;
 	sector_t next_sector;
 
-	void *orig_data;
-	report_zones_cb orig_cb;
 	unsigned int zone_idx;
 
+	/* for block layer ->report_zones */
+	struct blk_report_zones_args *rep_args;
+
+	/* for internal users */
+	report_zones_cb cb;
+	void *data;
+
 	/* must be filled by ->report_zones before calling dm_report_zones_cb */
 	sector_t start;
 };