[RFC PATCH 2/8] scsi: add REQ_OP_VERIFY support

[Chaitanya Kulkarni <chaitanyak@nvidia.com>]

From: Chaitanya Kulkarni <kch@nvidia.com>

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
---
 drivers/scsi/sd.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++
 drivers/scsi/sd.h |  1 +
 2 files changed, 53 insertions(+)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index a3d2d4bc4a3d..7f2c4eb98cf8 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -106,6 +106,7 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_ZBC);
 
 static void sd_config_discard(struct scsi_disk *, unsigned int);
 static void sd_config_write_same(struct scsi_disk *);
+static void sd_config_verify(struct scsi_disk *sdkp);
 static int  sd_revalidate_disk(struct gendisk *);
 static void sd_unlock_native_capacity(struct gendisk *disk);
 static int  sd_probe(struct device *);
@@ -995,6 +996,41 @@ static blk_status_t sd_setup_write_zeroes_cmnd(struct scsi_cmnd *cmd)
 	return sd_setup_write_same10_cmnd(cmd, false);
 }
 
+static void sd_config_verify(struct scsi_disk *sdkp)
+{
+	struct request_queue *q = sdkp->disk->queue;
+
+	/* XXX: use same pattern as sd_config_write_same(). */
+	blk_queue_max_verify_sectors(q, UINT_MAX >> 9);
+}
+
+static blk_status_t sd_setup_verify_cmnd(struct scsi_cmnd *cmd)
+{
+       struct request *rq = cmd->request;
+       struct scsi_device *sdp = cmd->device;
+       struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+       u64 lba = sectors_to_logical(sdp, blk_rq_pos(rq));
+       u32 nr_blocks = sectors_to_logical(sdp, blk_rq_sectors(rq));
+
+       if (!sdkp->verify_16)
+	       return BLK_STS_NOTSUPP;
+
+       cmd->cmd_len = 16;
+       cmd->cmnd[0] = VERIFY_16;
+       /* skip veprotect / dpo / bytchk */
+       cmd->cmnd[1] = 0;
+       put_unaligned_be64(lba, &cmd->cmnd[2]);
+       put_unaligned_be32(nr_blocks, &cmd->cmnd[10]);
+       cmd->cmnd[14] = 0;
+       cmd->cmnd[15] = 0;
+
+       cmd->allowed = SD_MAX_RETRIES;
+       cmd->sc_data_direction = DMA_NONE;
+       cmd->transfersize = 0;
+
+       return BLK_STS_OK;
+}
+
 static void sd_config_write_same(struct scsi_disk *sdkp)
 {
 	struct request_queue *q = sdkp->disk->queue;
@@ -1345,6 +1381,8 @@ static blk_status_t sd_init_command(struct scsi_cmnd *cmd)
 		}
 	case REQ_OP_WRITE_ZEROES:
 		return sd_setup_write_zeroes_cmnd(cmd);
+	case REQ_OP_VERIFY:
+		return sd_setup_verify_cmnd(cmd);
 	case REQ_OP_WRITE_SAME:
 		return sd_setup_write_same_cmnd(cmd);
 	case REQ_OP_FLUSH:
@@ -2029,6 +2067,7 @@ static int sd_done(struct scsi_cmnd *SCpnt)
 	switch (req_op(req)) {
 	case REQ_OP_DISCARD:
 	case REQ_OP_WRITE_ZEROES:
+	case REQ_OP_VERIFY:
 	case REQ_OP_WRITE_SAME:
 	case REQ_OP_ZONE_RESET:
 	case REQ_OP_ZONE_RESET_ALL:
@@ -3096,6 +3135,17 @@ static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
 		sdkp->ws10 = 1;
 }
 
+static void sd_read_verify(struct scsi_disk *sdkp, unsigned char *buffer)
+{
+       struct scsi_device *sdev = sdkp->device;
+
+       sd_printk(KERN_INFO, sdkp, "VERIFY16 check.\n");
+       if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, VERIFY_16) == 1) {
+	       sd_printk(KERN_INFO, sdkp, " VERIFY16 in ON .\n");
+               sdkp->verify_16 = 1;
+       }
+}
+
 static void sd_read_security(struct scsi_disk *sdkp, unsigned char *buffer)
 {
 	struct scsi_device *sdev = sdkp->device;
@@ -3224,6 +3274,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
 		sd_read_cache_type(sdkp, buffer);
 		sd_read_app_tag_own(sdkp, buffer);
 		sd_read_write_same(sdkp, buffer);
+		sd_read_verify(sdkp, buffer);
 		sd_read_security(sdkp, buffer);
 	}
 
@@ -3265,6 +3316,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
 
 	set_capacity_and_notify(disk, logical_to_sectors(sdp, sdkp->capacity));
 	sd_config_write_same(sdkp);
+	sd_config_verify(sdkp);
 	kfree(buffer);
 
 	/*
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index b59136c4125b..94a86bf6dac4 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -120,6 +120,7 @@ struct scsi_disk {
 	unsigned	lbpvpd : 1;
 	unsigned	ws10 : 1;
 	unsigned	ws16 : 1;
+	unsigned        verify_16 : 1;
 	unsigned	rc_basis: 2;
 	unsigned	zoned: 2;
 	unsigned	urswrz : 1;
-- 
2.22.1