Merge patch series "Use block pr_ops in LIO"

Mike Christie <michael.christie@oracle.com> says:

The patches in this thread allow us to use the block pr_ops with LIO's
target_core_iblock module to support cluster applications in VMs. They
were built over Linus's tree. They also apply over linux-next and
Martin's tree and Jens's trees.

Currently, to use windows clustering or linux clustering (pacemaker +
cluster labs scsi fence agents) in VMs with LIO and vhost-scsi, you
have to use tcmu or pscsi or use a cluster aware FS/framework for the
LIO pr file. Setting up a cluster FS/framework is pain and waste when
your real backend device is already a distributed device, and pscsi
and tcmu are nice for specific use cases, but iblock gives you the
best performance and allows you to use stacked devices like
dm-multipath. So these patches allow iblock to work like pscsi/tcmu
where they can pass a PR command to the backend module. And then
iblock will use the pr_ops to pass the PR command to the real devices
similar to what we do for unmap today.

The patches are separated in the following groups:

Patch 1 - 2:

 - Add block layer callouts for reading reservations and rename reservation
   error code.

Patch 3 - 5:

 - SCSI support for new callouts.

Patch 6:

 - DM support for new callouts.

Patch 7 - 13:

 - NVMe support for new callouts.

Patch 14 - 18:

 - LIO support for new callouts.

This patchset has been tested with the libiscsi PGR ops and with
window's failover cluster verification test. Note that for scsi
backend devices we need this patchset:

https://lore.kernel.org/linux-scsi/20230123221046.125483-1-michael.christie@oracle.com/T/#m4834a643ffb5bac2529d65d40906d3cfbdd9b1b7

to handle UAs. To reduce the size of this patchset that's being done
separately to make reviewing easier. And to make merging easier this
patchset and the one above do not have any conflicts so can be merged
in different trees.

Link: https://lore.kernel.org/r/20230407200551.12660-1-michael.christie@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 79 insertions, 34 deletions

diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 89c0d56294cc..50290abc07bc 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -1424,9 +1424,10 @@ static struct target_opcode_descriptor tcm_opcode_write_verify16 = {
 	.update_usage_bits = set_dpofua_usage_bits,
 };
 
-static bool tcm_is_ws_enabled(struct se_cmd *cmd)
+static bool tcm_is_ws_enabled(struct target_opcode_descriptor *descr,
+			      struct se_cmd *cmd)
 {
-	struct sbc_ops *ops = cmd->protocol_data;
+	struct exec_cmd_ops *ops = cmd->protocol_data;
 	struct se_device *dev = cmd->se_dev;
 
 	return (dev->dev_attrib.emulate_tpws && !!ops->execute_unmap) ||
@@ -1451,7 +1452,8 @@ static struct target_opcode_descriptor tcm_opcode_write_same32 = {
 	.update_usage_bits = set_dpofua_usage_bits32,
 };
 
-static bool tcm_is_caw_enabled(struct se_cmd *cmd)
+static bool tcm_is_caw_enabled(struct target_opcode_descriptor *descr,
+			       struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
@@ -1491,7 +1493,8 @@ static struct target_opcode_descriptor tcm_opcode_read_capacity16 = {
 		       0xff, 0xff, 0x00, SCSI_CONTROL_MASK},
 };
 
-static bool tcm_is_rep_ref_enabled(struct se_cmd *cmd)
+static bool tcm_is_rep_ref_enabled(struct target_opcode_descriptor *descr,
+				   struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
@@ -1502,7 +1505,6 @@ static bool tcm_is_rep_ref_enabled(struct se_cmd *cmd)
 	}
 	spin_unlock(&dev->t10_alua.lba_map_lock);
 	return true;
-
 }
 
 static struct target_opcode_descriptor tcm_opcode_read_report_refferals = {
@@ -1537,9 +1539,10 @@ static struct target_opcode_descriptor tcm_opcode_sync_cache16 = {
 		       0xff, 0xff, SCSI_GROUP_NUMBER_MASK, SCSI_CONTROL_MASK},
 };
 
-static bool tcm_is_unmap_enabled(struct se_cmd *cmd)
+static bool tcm_is_unmap_enabled(struct target_opcode_descriptor *descr,
+				 struct se_cmd *cmd)
 {
-	struct sbc_ops *ops = cmd->protocol_data;
+	struct exec_cmd_ops *ops = cmd->protocol_data;
 	struct se_device *dev = cmd->se_dev;
 
 	return ops->execute_unmap && dev->dev_attrib.emulate_tpu;
@@ -1659,11 +1662,46 @@ static struct target_opcode_descriptor tcm_opcode_pri_read_resrv = {
 		       0xff, SCSI_CONTROL_MASK},
 };
 
-static bool tcm_is_pr_enabled(struct se_cmd *cmd)
+static bool tcm_is_pr_enabled(struct target_opcode_descriptor *descr,
+			      struct se_cmd *cmd)
 {
 	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 = {
@@ -1788,20 +1826,13 @@ static struct target_opcode_descriptor tcm_opcode_pro_register_move = {
 	.enabled = tcm_is_pr_enabled,
 };
 
-static bool tcm_is_scsi2_reservations_enabled(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 = {
@@ -1811,7 +1842,7 @@ 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 = {
@@ -1820,7 +1851,7 @@ 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 = {
@@ -1830,7 +1861,7 @@ 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 = {
@@ -1849,7 +1880,8 @@ static struct target_opcode_descriptor tcm_opcode_inquiry = {
 		       0xff, SCSI_CONTROL_MASK},
 };
 
-static bool tcm_is_3pc_enabled(struct se_cmd *cmd)
+static bool tcm_is_3pc_enabled(struct target_opcode_descriptor *descr,
+			       struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
@@ -1910,8 +1942,8 @@ static struct target_opcode_descriptor tcm_opcode_report_target_pgs = {
 		       0xff, 0xff, 0x00, SCSI_CONTROL_MASK},
 };
 
-
-static bool spc_rsoc_enabled(struct se_cmd *cmd)
+static bool spc_rsoc_enabled(struct target_opcode_descriptor *descr,
+			     struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
@@ -1931,7 +1963,8 @@ static struct target_opcode_descriptor tcm_opcode_report_supp_opcodes = {
 	.enabled = spc_rsoc_enabled,
 };
 
-static bool tcm_is_set_tpg_enabled(struct se_cmd *cmd)
+static bool tcm_is_set_tpg_enabled(struct target_opcode_descriptor *descr,
+				   struct se_cmd *cmd)
 {
 	struct t10_alua_tg_pt_gp *l_tg_pt_gp;
 	struct se_lun *l_lun = cmd->se_lun;
@@ -2118,7 +2151,7 @@ spc_rsoc_get_descr(struct se_cmd *cmd, struct target_opcode_descriptor **opcode)
 			if (descr->serv_action_valid)
 				return TCM_INVALID_CDB_FIELD;
 
-			if (!descr->enabled || descr->enabled(cmd))
+			if (!descr->enabled || descr->enabled(descr, cmd))
 				*opcode = descr;
 			break;
 		case 0x2:
@@ -2132,7 +2165,8 @@ spc_rsoc_get_descr(struct se_cmd *cmd, struct target_opcode_descriptor **opcode)
 			 */
 			if (descr->serv_action_valid &&
 			    descr->service_action == requested_sa) {
-				if (!descr->enabled || descr->enabled(cmd))
+				if (!descr->enabled || descr->enabled(descr,
+								      cmd))
 					*opcode = descr;
 			} else if (!descr->serv_action_valid)
 				return TCM_INVALID_CDB_FIELD;
@@ -2145,7 +2179,8 @@ spc_rsoc_get_descr(struct se_cmd *cmd, struct target_opcode_descriptor **opcode)
 			 * be returned in the one_command parameter data format.
 			 */
 			if (descr->service_action == requested_sa)
-				if (!descr->enabled || descr->enabled(cmd))
+				if (!descr->enabled || descr->enabled(descr,
+								      cmd))
 					*opcode = descr;
 			break;
 		}
@@ -2202,7 +2237,7 @@ spc_emulate_report_supp_op_codes(struct se_cmd *cmd)
 
 		for (i = 0; i < ARRAY_SIZE(tcm_supported_opcodes); i++) {
 			descr = tcm_supported_opcodes[i];
-			if (descr->enabled && !descr->enabled(cmd))
+			if (descr->enabled && !descr->enabled(descr, cmd))
 				continue;
 
 			response_length += spc_rsoc_encode_command_descriptor(
@@ -2231,12 +2266,22 @@ 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]) {