diff mbox

target: add support for START_STOP_UNIT SCSI opcode

Message ID 1437516477-30554-1-git-send-email-sbaugh@catern.com (mailing list archive)
State New, archived
Headers show

Commit Message

Spencer Baugh July 21, 2015, 10:07 p.m. UTC 
From: Brian Bunker <brian@purestorage.com>

AIX servers using VIOS servers that virtualize FC cards will have a
problem booting without support for START_STOP_UNIT.

Signed-off-by: Brian Bunker <brian@purestorage.com>
Signed-off-by: Spencer Baugh <sbaugh@catern.com>
---
 drivers/target/target_core_sbc.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

Comments

Christoph Hellwig July 23, 2015, 9:36 a.m. UTC | #1 
On Tue, Jul 21, 2015 at 03:07:53PM -0700, Spencer Baugh wrote:
> +static sense_reason_t
> +sbc_emulate_startstop(struct se_cmd *cmd)
> +{
> +	unsigned char *cdb = cmd->t_task_cdb;
> +
> +	/* From SBC-3:
> +	 * Immediate bit should be set since there is nothing to complete
> +	 * POWER CONDITION MODIFIER 0h
> +	 */

Mot of the target code mentions the exact document and section, e.g.

drivers/target/target_core_alua.c: * See sbc3r35 section 5.23
drivers/target/target_core_sbc.c:        * Set Thin Provisioning Enable bit following sbc3r22 in section
drivers/target/target_core_sbc.c:        * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command

Also if you fix thing up anyway the Linux style is to keep the opening
"/*" on a separate line.

> +	if (!(cdb[1] & 1) || (cdb[2] | cdb[3]))
> +		return TCM_INVALID_CDB_FIELD;

The mix of || and | here is odd, why not just:

 if (!(cdb[1] & 1) || cdb[2] || cdb[3])

> +	if (!(cdb[4] & 1) || ((cdb[4] & 2) | (cdb[4] & 4)))

Same here.

But except for this nitpicking the patch looks good:


Reviewed-by: Christoph Hellwig <hch@lst.de>
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diff mbox

Patch

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index e318ddb..996e584 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -154,6 +154,35 @@  sbc_emulate_readcapacity_16(struct se_cmd *cmd)
 	return 0;
 }
 
+static sense_reason_t
+sbc_emulate_startstop(struct se_cmd *cmd)
+{
+	unsigned char *cdb = cmd->t_task_cdb;
+
+	/* From SBC-3:
+	 * Immediate bit should be set since there is nothing to complete
+	 * POWER CONDITION MODIFIER 0h
+	 */
+	if (!(cdb[1] & 1) || (cdb[2] | cdb[3]))
+		return TCM_INVALID_CDB_FIELD;
+
+	/* From SBC-3:
+	 * POWER CONDITION 0h START_VALID - process START and LOEJ
+	 */
+	if (cdb[4] >> 4 & 0xf)
+		return TCM_INVALID_CDB_FIELD;
+
+	/* From SBC-3:
+	 * LOEJ 0h - nothing to load or unload
+	 * START 1h - we are ready
+	 */
+	if (!(cdb[4] & 1) || ((cdb[4] & 2) | (cdb[4] & 4)))
+		return TCM_INVALID_CDB_FIELD;
+
+	target_complete_cmd(cmd, SAM_STAT_GOOD);
+	return 0;
+}
+
 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 {
 	u32 num_blocks;
@@ -1069,6 +1098,10 @@  sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 		size = 0;
 		cmd->execute_cmd = sbc_emulate_noop;
 		break;
+	case START_STOP:
+		size = 0;
+		cmd->execute_cmd = sbc_emulate_startstop;
+		break;
 	default:
 		ret = spc_parse_cdb(cmd, &size);
 		if (ret)