[PATCH v6 19/20] scsi: scsi_debug: Implement GET STREAM STATUS

[Bart Van Assche <bvanassche@acm.org>]

Implement the GET STREAM STATUS SCSI command. Report that the first
five stream indexes correspond to permanent streams.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_debug.c | 50 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 4e18265a05da..b2146f24f396 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -533,6 +533,8 @@ static int resp_write_scat(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_start_stop(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_readcap16(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_get_lba_status(struct scsi_cmnd *, struct sdebug_dev_info *);
+static int resp_get_stream_status(struct scsi_cmnd *scp,
+				  struct sdebug_dev_info *devip);
 static int resp_report_tgtpgs(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_unmap(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_rsup_opcodes(struct scsi_cmnd *, struct sdebug_dev_info *);
@@ -607,6 +609,9 @@ static const struct opcode_info_t sa_in_16_iarr[] = {
 	{0, 0x9e, 0x12, F_SA_LOW | F_D_IN, resp_get_lba_status, NULL,
 	    {16,  0x12, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 	     0xff, 0xff, 0xff, 0, 0xc7} },	/* GET LBA STATUS(16) */
+	{0, 0x9e, 0x16, F_SA_LOW | F_D_IN, resp_get_stream_status, NULL,
+	    {16, 0x16, 0, 0, 0xff, 0xff, 0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff,
+	     0, 0} },	/* GET STREAM STATUS */
 };
 
 static const struct opcode_info_t vl_iarr[] = {	/* VARIABLE LENGTH */
@@ -4581,6 +4586,51 @@ static int resp_get_lba_status(struct scsi_cmnd *scp,
 	return fill_from_dev_buffer(scp, arr, SDEBUG_GET_LBA_STATUS_LEN);
 }
 
+static int resp_get_stream_status(struct scsi_cmnd *scp,
+				  struct sdebug_dev_info *devip)
+{
+	u16 starting_stream_id, stream_id;
+	const u8 *cmd = scp->cmnd;
+	u32 alloc_len, offset;
+	u8 arr[256] = {};
+	struct scsi_stream_status_header *h = (void *)arr;
+
+	starting_stream_id = get_unaligned_be16(cmd + 4);
+	alloc_len = get_unaligned_be32(cmd + 10);
+
+	if (alloc_len < 8) {
+		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 10, -1);
+		return check_condition_result;
+	}
+
+	if (starting_stream_id >= MAXIMUM_NUMBER_OF_STREAMS) {
+		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 4, -1);
+		return check_condition_result;
+	}
+
+	/*
+	 * The GET STREAM STATUS command only reports status information
+	 * about open streams. Treat the non-permanent stream as open.
+	 */
+	put_unaligned_be16(MAXIMUM_NUMBER_OF_STREAMS,
+			   &h->number_of_open_streams);
+
+	for (offset = 8, stream_id = starting_stream_id;
+	     offset + 8 <= min_t(u32, alloc_len, sizeof(arr)) &&
+		     stream_id < MAXIMUM_NUMBER_OF_STREAMS;
+	     offset += 8, stream_id++) {
+		struct scsi_stream_status *stream_status = (void *)arr + offset;
+
+		stream_status->perm = stream_id < PERMANENT_STREAM_COUNT;
+		put_unaligned_be16(stream_id,
+				   &stream_status->stream_identifier);
+		stream_status->rel_lifetime = stream_id + 1;
+	}
+	put_unaligned_be32(offset - 8, &h->len); /* PARAMETER DATA LENGTH */
+
+	return fill_from_dev_buffer(scp, arr, min(offset, alloc_len));
+}
+
 static int resp_sync_cache(struct scsi_cmnd *scp,
 			   struct sdebug_dev_info *devip)
 {