[PATCH 04/11] null_blk: Support REQ_OP_ZONE_APPEND

[Johannes Thumshirn <johannes.thumshirn@xxxxxxx>]

From: Damien Le Moal <damien.lemoal@xxxxxxx>

Support REQ_OP_ZONE_APPEND requests for zone mode null_blk devices.
Use the internally tracked zone write pointer position as the write
position.

Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
---
 drivers/block/null_blk_main.c  |  9 ++++++---
 drivers/block/null_blk_zoned.c | 21 ++++++++++++++++++---
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index 133060431dbd..62869431f2cf 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -1575,15 +1575,18 @@ static int null_gendisk_register(struct nullb *nullb)
 
 #ifdef CONFIG_BLK_DEV_ZONED
 	if (nullb->dev->zoned) {
-		if (queue_is_mq(nullb->q)) {
+		struct request_queue *q = nullb->q;
+
+		if (queue_is_mq(q)) {
 			int ret = blk_revalidate_disk_zones(disk);
 			if (ret)
 				return ret;
 		} else {
-			blk_queue_chunk_sectors(nullb->q,
+			blk_queue_chunk_sectors(q,
 					nullb->dev->zone_size_sects);
-			nullb->q->nr_zones = blkdev_nr_zones(disk);
+			q->nr_zones = blkdev_nr_zones(disk);
 		}
+		blk_queue_max_zone_append_sectors(q, q->limits.max_hw_sectors);
 	}
 #endif
 
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index ed34785dd64b..ed9c4cde68f3 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -116,7 +116,7 @@ size_t null_zone_valid_read_len(struct nullb *nullb,
 }
 
 static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
-		     unsigned int nr_sectors)
+		     		    unsigned int nr_sectors, bool append)
 {
 	struct nullb_device *dev = cmd->nq->dev;
 	unsigned int zno = null_zone_no(dev, sector);
@@ -131,7 +131,20 @@ static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
 	case BLK_ZONE_COND_IMP_OPEN:
 	case BLK_ZONE_COND_EXP_OPEN:
 	case BLK_ZONE_COND_CLOSED:
-		/* Writes must be at the write pointer position */
+		/*
+		 * Regular writes must be at the write pointer position.
+		 * Zone append writes are automatically issued at the write
+		 * pointer and the position returned using the request or BIO
+		 * sector.
+		 */
+		if (append) {
+			sector = zone->wp;
+			if (cmd->bio)
+				cmd->bio->bi_iter.bi_sector = sector;
+			else
+				cmd->rq->__sector = sector;
+		}
+
 		if (sector != zone->wp)
 			return BLK_STS_IOERR;
 
@@ -211,7 +224,9 @@ blk_status_t null_handle_zoned(struct nullb_cmd *cmd, enum req_opf op,
 {
 	switch (op) {
 	case REQ_OP_WRITE:
-		return null_zone_write(cmd, sector, nr_sectors);
+		return null_zone_write(cmd, sector, nr_sectors, false);
+	case REQ_OP_ZONE_APPEND:
+		return null_zone_write(cmd, sector, nr_sectors, true);
 	case REQ_OP_ZONE_RESET:
 	case REQ_OP_ZONE_RESET_ALL:
 	case REQ_OP_ZONE_OPEN:
-- 
2.24.1