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>

2 files changed, 8 insertions, 14 deletions

diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 36382eca941c..574af8243016 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -240,7 +240,7 @@ blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
 unsigned int sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
 			     struct scsi_sense_hdr *sshdr);
 int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
-		unsigned int nr_zones, report_zones_cb cb, void *data);
+		unsigned int nr_zones, struct blk_report_zones_args *args);
 
 #else /* CONFIG_BLK_DEV_ZONED */
 
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index a8db66428f80..56e455fb5add 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -35,8 +35,7 @@ static bool sd_zbc_is_gap_zone(const u8 buf[64])
  * @buf: SCSI zone descriptor.
  * @idx: Index of the zone relative to the first zone reported by the current
  *	sd_zbc_report_zones() call.
- * @cb: Callback function pointer.
- * @data: Second argument passed to @cb.
+ * @args: report zones arguments (callback, etc)
  *
  * Return: Value returned by @cb.
  *
@@ -44,12 +43,11 @@ static bool sd_zbc_is_gap_zone(const u8 buf[64])
  * call @cb(blk_zone, @data).
  */
 static int sd_zbc_parse_report(struct scsi_disk *sdkp, const u8 buf[64],
-			       unsigned int idx, report_zones_cb cb, void *data)
+			unsigned int idx, struct blk_report_zones_args *args)
 {
 	struct scsi_device *sdp = sdkp->device;
 	struct blk_zone zone = { 0 };
 	sector_t start_lba, gran;
-	int ret;
 
 	if (WARN_ON_ONCE(sd_zbc_is_gap_zone(buf)))
 		return -EINVAL;
@@ -87,11 +85,7 @@ static int sd_zbc_parse_report(struct scsi_disk *sdkp, const u8 buf[64],
 	else
 		zone.wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
 
-	ret = cb(&zone, idx, data);
-	if (ret)
-		return ret;
-
-	return 0;
+	return disk_report_zone(sdkp->disk, &zone, idx, args);
 }
 
 /**
@@ -217,14 +211,14 @@ static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
  * @disk: Disk to report zones for.
  * @sector: Start sector.
  * @nr_zones: Maximum number of zones to report.
- * @cb: Callback function called to report zone information.
- * @data: Second argument passed to @cb.
+ * @args: Callback arguments.
  *
  * Called by the block layer to iterate over zone information. See also the
  * disk->fops->report_zones() calls in block/blk-zoned.c.
  */
 int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
-			unsigned int nr_zones, report_zones_cb cb, void *data)
+			unsigned int nr_zones,
+			struct blk_report_zones_args *args)
 {
 	struct scsi_disk *sdkp = scsi_disk(disk);
 	sector_t lba = sectors_to_logical(sdkp->device, sector);
@@ -283,7 +277,7 @@ int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
 			}
 
 			ret = sd_zbc_parse_report(sdkp, buf + offset, zone_idx,
-						  cb, data);
+						  args);
 			if (ret)
 				goto out;