target/user: PGR Support

This adds initial PGR support for just TCMU, since tcmu doesn't
have the necessary IT_NEXUS info to process PGR in userspace,
so have those commands be processed in kernel.

HA support is not available yet, we will work on it if this patch
is acceptable.

Signed-off-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

4 files changed, 46 insertions, 7 deletions

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index a34a8665..e7b62bc 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1400,7 +1400,7 @@ static ssize_t target_pr_res_holder_show(struct config_item *item, char *page)
 	struct se_device *dev = pr_to_dev(item);
 	int ret;
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
 		return sprintf(page, "Passthrough\n");
 
 	spin_lock(&dev->dev_reservation_lock);
@@ -1540,7 +1540,7 @@ static ssize_t target_pr_res_type_show(struct config_item *item, char *page)
 {
 	struct se_device *dev = pr_to_dev(item);
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
 		return sprintf(page, "SPC_PASSTHROUGH\n");
 	else if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
 		return sprintf(page, "SPC2_RESERVATIONS\n");
@@ -1553,7 +1553,7 @@ static ssize_t target_pr_res_aptpl_active_show(struct config_item *item,
 {
 	struct se_device *dev = pr_to_dev(item);
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
 		return 0;
 
 	return sprintf(page, "APTPL Bit Status: %s\n",
@@ -1565,7 +1565,7 @@ static ssize_t target_pr_res_aptpl_metadata_show(struct config_item *item,
 {
 	struct se_device *dev = pr_to_dev(item);
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
 		return 0;
 
 	return sprintf(page, "Ready to process PR APTPL metadata..\n");
@@ -1611,7 +1611,7 @@ static ssize_t target_pr_res_aptpl_metadata_store(struct config_item *item,
 	u16 tpgt = 0;
 	u8 type = 0;
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
 		return count;
 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
 		return count;
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index c754ae3..c484567 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -1045,6 +1045,8 @@ passthrough_parse_cdb(struct se_cmd *cmd,
 	sense_reason_t (*exec_cmd)(struct se_cmd *cmd))
 {
 	unsigned char *cdb = cmd->t_task_cdb;
+	struct se_device *dev = cmd->se_dev;
+	unsigned int size;
 
 	/*
 	 * Clear a lun set in the cdb if the initiator talking to use spoke
@@ -1076,6 +1078,42 @@ passthrough_parse_cdb(struct se_cmd *cmd,
 		return TCM_NO_SENSE;
 	}
 
+	/*
+	 * For PERSISTENT RESERVE IN/OUT, RELEASE, and RESERVE we need to
+	 * emulate the response, since tcmu does not have the information
+	 * required to process these commands.
+	 */
+	if (!(dev->transport->transport_flags &
+	      TRANSPORT_FLAG_PASSTHROUGH_PGR)) {
+		if (cdb[0] == PERSISTENT_RESERVE_IN) {
+			cmd->execute_cmd = target_scsi3_emulate_pr_in;
+			size = (cdb[7] << 8) + cdb[8];
+			return target_cmd_size_check(cmd, size);
+		}
+		if (cdb[0] == PERSISTENT_RESERVE_OUT) {
+			cmd->execute_cmd = target_scsi3_emulate_pr_out;
+			size = (cdb[7] << 8) + cdb[8];
+			return target_cmd_size_check(cmd, size);
+		}
+
+		if (cdb[0] == RELEASE || cdb[0] == RELEASE_10) {
+			cmd->execute_cmd = target_scsi2_reservation_release;
+			if (cdb[0] == RELEASE_10)
+				size = (cdb[7] << 8) | cdb[8];
+			else
+				size = cmd->data_length;
+			return target_cmd_size_check(cmd, size);
+		}
+		if (cdb[0] == RESERVE || cdb[0] == RESERVE_10) {
+			cmd->execute_cmd = target_scsi2_reservation_reserve;
+			if (cdb[0] == RESERVE_10)
+				size = (cdb[7] << 8) | cdb[8];
+			else
+				size = cmd->data_length;
+			return target_cmd_size_check(cmd, size);
+		}
+	}
+
 	/* Set DATA_CDB flag for ops that should have it */
 	switch (cdb[0]) {
 	case READ_6:
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index e180511..129ca57 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -4147,7 +4147,7 @@ target_check_reservation(struct se_cmd *cmd)
 		return 0;
 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
 		return 0;
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
 		return 0;
 
 	spin_lock(&dev->dev_reservation_lock);
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 94cda79..8943a62 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -1081,7 +1081,8 @@ static const struct target_backend_ops pscsi_ops = {
 	.name			= "pscsi",
 	.owner			= THIS_MODULE,
 	.transport_flags	= TRANSPORT_FLAG_PASSTHROUGH |
-				  TRANSPORT_FLAG_PASSTHROUGH_ALUA,
+				  TRANSPORT_FLAG_PASSTHROUGH_ALUA |
+				  TRANSPORT_FLAG_PASSTHROUGH_PGR,
 	.attach_hba		= pscsi_attach_hba,
 	.detach_hba		= pscsi_detach_hba,
 	.pmode_enable_hba	= pscsi_pmode_enable_hba,