[PATCH v4 17/18] scsi: target: Report and detect unsupported PR commands

[Mike Christie <michael.christie@oracle.com>]

The backend modules don't know about ports and I_T nexuses and the pr_ops
callouts the modules will use don't support the old RESERVE/RELEASE
commands. This patch has us report we don't support those types of
commands and fail them.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/target/target_core_pr.c  | 17 ++++++++
 drivers/target/target_core_spc.c | 75 +++++++++++++++++++++++---------
 2 files changed, 72 insertions(+), 20 deletions(-)

diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index e16ef7d676af..7a3f07979a02 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -3554,6 +3554,18 @@ target_try_pr_out_pt(struct se_cmd *cmd, u8 sa, u64 res_key, u64 sa_res_key,
 		return TCM_UNSUPPORTED_SCSI_OPCODE;
 	}
 
+	switch (sa) {
+	case PRO_REGISTER_AND_MOVE:
+	case PRO_REPLACE_LOST_RESERVATION:
+		pr_err("SPC-3 PR: PRO_REGISTER_AND_MOVE and PRO_REPLACE_LOST_RESERVATION are not supported by PR passthrough.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	if (spec_i_pt || all_tg_pt) {
+		pr_err("SPC-3 PR: SPEC_I_PT and ALL_TG_PT are not supported by PR passthrough.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
 	return ops->execute_pr_out(cmd, sa, res_key, sa_res_key, type, aptpl);
 }
 
@@ -4082,6 +4094,11 @@ static sense_reason_t target_try_pr_in_pt(struct se_cmd *cmd, u8 sa)
 		return TCM_UNSUPPORTED_SCSI_OPCODE;
 	}
 
+	if (sa == PRI_READ_FULL_STATUS) {
+		pr_err("SPC-3 PR: PRI_READ_FULL_STATUS is not supported by PR passthrough.\n");
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
 	buf = transport_kmap_data_sg(cmd);
 	if (!buf)
 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index caf8d1325007..053bd2eea0e6 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -1672,7 +1672,41 @@ static bool tcm_is_pr_enabled(struct target_opcode_descriptor *descr,
 {
 	struct se_device *dev = cmd->se_dev;
 
-	return dev->dev_attrib.emulate_pr;
+	if (!dev->dev_attrib.emulate_pr)
+		return false;
+
+	if (!(dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
+		return true;
+
+	switch (descr->opcode) {
+	case RESERVE:
+	case RESERVE_10:
+	case RELEASE:
+	case RELEASE_10:
+		/*
+		 * The pr_ops which are used by the backend modules don't
+		 * support these commands.
+		 */
+		return false;
+	case PERSISTENT_RESERVE_OUT:
+		switch (descr->service_action) {
+		case PRO_REGISTER_AND_MOVE:
+		case PRO_REPLACE_LOST_RESERVATION:
+			/*
+			 * The backend modules don't have access to ports and
+			 * I_T nexuses so they can't handle these type of
+			 * requests.
+			 */
+			return false;
+		}
+		break;
+	case PERSISTENT_RESERVE_IN:
+		if (descr->service_action == PRI_READ_FULL_STATUS)
+			return false;
+		break;
+	}
+
+	return true;
 }
 
 static struct target_opcode_descriptor tcm_opcode_pri_read_caps = {
@@ -1797,22 +1831,13 @@ static struct target_opcode_descriptor tcm_opcode_pro_register_move = {
 	.enabled = tcm_is_pr_enabled,
 };
 
-static bool
-tcm_is_scsi2_reservations_enabled(struct target_opcode_descriptor *descr,
-				  struct se_cmd *cmd)
-{
-	struct se_device *dev = cmd->se_dev;
-
-	return dev->dev_attrib.emulate_pr;
-}
-
 static struct target_opcode_descriptor tcm_opcode_release = {
 	.support = SCSI_SUPPORT_FULL,
 	.opcode = RELEASE,
 	.cdb_size = 6,
 	.usage_bits = {RELEASE, 0x00, 0x00, 0x00,
 		       0x00, SCSI_CONTROL_MASK},
-	.enabled = tcm_is_scsi2_reservations_enabled,
+	.enabled = tcm_is_pr_enabled,
 };
 
 static struct target_opcode_descriptor tcm_opcode_release10 = {
@@ -1822,7 +1847,7 @@ static struct target_opcode_descriptor tcm_opcode_release10 = {
 	.usage_bits = {RELEASE_10, 0x00, 0x00, 0x00,
 		       0x00, 0x00, 0x00, 0xff,
 		       0xff, SCSI_CONTROL_MASK},
-	.enabled = tcm_is_scsi2_reservations_enabled,
+	.enabled = tcm_is_pr_enabled,
 };
 
 static struct target_opcode_descriptor tcm_opcode_reserve = {
@@ -1831,7 +1856,7 @@ static struct target_opcode_descriptor tcm_opcode_reserve = {
 	.cdb_size = 6,
 	.usage_bits = {RESERVE, 0x00, 0x00, 0x00,
 		       0x00, SCSI_CONTROL_MASK},
-	.enabled = tcm_is_scsi2_reservations_enabled,
+	.enabled = tcm_is_pr_enabled,
 };
 
 static struct target_opcode_descriptor tcm_opcode_reserve10 = {
@@ -1841,7 +1866,7 @@ static struct target_opcode_descriptor tcm_opcode_reserve10 = {
 	.usage_bits = {RESERVE_10, 0x00, 0x00, 0x00,
 		       0x00, 0x00, 0x00, 0xff,
 		       0xff, SCSI_CONTROL_MASK},
-	.enabled = tcm_is_scsi2_reservations_enabled,
+	.enabled = tcm_is_pr_enabled,
 };
 
 static struct target_opcode_descriptor tcm_opcode_request_sense = {
@@ -2246,12 +2271,22 @@ spc_parse_cdb(struct se_cmd *cmd, unsigned int *size)
 	struct se_device *dev = cmd->se_dev;
 	unsigned char *cdb = cmd->t_task_cdb;
 
-	if (!dev->dev_attrib.emulate_pr &&
-	    ((cdb[0] == PERSISTENT_RESERVE_IN) ||
-	     (cdb[0] == PERSISTENT_RESERVE_OUT) ||
-	     (cdb[0] == RELEASE || cdb[0] == RELEASE_10) ||
-	     (cdb[0] == RESERVE || cdb[0] == RESERVE_10))) {
-		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	switch (cdb[0]) {
+	case RESERVE:
+	case RESERVE_10:
+	case RELEASE:
+	case RELEASE_10:
+		if (!dev->dev_attrib.emulate_pr)
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+
+		if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+		break;
+	case PERSISTENT_RESERVE_IN:
+	case PERSISTENT_RESERVE_OUT:
+		if (!dev->dev_attrib.emulate_pr)
+			return TCM_UNSUPPORTED_SCSI_OPCODE;
+		break;
 	}
 
 	switch (cdb[0]) {
-- 
2.25.1