[PATCH 0/4] target: tcmu: allow flexible pr and alua handling

[PATCH 0/4] target: tcmu: allow flexible pr and alua handling

[Bodo Stroesser]

These patches already were sent to target-devel only. So I'm resending
them now, slightly modified according to review comments from
target-devel.

The goal of the patches is to add more flexibility to tcmu regarding
PGR handling.

Since the attribute emulate_pr is missing for pscsi in the same way as
for tcmu, I'm adding it to pscsi also. 

[PATCH 0/4] target: tcmu: allow flexible pr and alua handling

[Bodo Stroesser]

These patches already were sent to target-devel only. So I'm resending
them now, slightly modified according to review comments from
target-devel.

The goal of the patches is to add more flexibility to tcmu regarding
PGR handling.

Since the attribute emulate_pr is missing for pscsi in the same way as
for tcmu, I'm adding it to pscsi also. 

[PATCH 1/4] target: add missing emulate_pr attribute to passthrough backends

[Bodo Stroesser]

In commit b49d6f7885306ee636d5c1af52170f3069ccf5f7 the new attribute
emulate_pr was added.
passthrough_parse_cdb() uses the attribute's value to distinguish,
whether reservation commands should be rejected or not.
But the new attribute was not added to passthrough_attrib_attrs, so in
pscsi and tcmu - the users of passthrough_parse_cdb() - the attribute
is not available to change parser's behavior.

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
---
 drivers/target/target_core_configfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index ff82b21fdcce..d8589bb39c53 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1203,6 +1203,7 @@ struct configfs_attribute *passthrough_attrib_attrs[] = {
 	&attr_hw_block_size,
 	&attr_hw_max_sectors,
 	&attr_hw_queue_depth,
+	&attr_emulate_pr,
 	&attr_alua_support,
 	&attr_pgr_support,
 	NULL,
-- 
2.12.3

[PATCH 1/4] target: add missing emulate_pr attribute to passthrough backends

[Bodo Stroesser]

In commit b49d6f7885306ee636d5c1af52170f3069ccf5f7 the new attribute
emulate_pr was added.
passthrough_parse_cdb() uses the attribute's value to distinguish,
whether reservation commands should be rejected or not.
But the new attribute was not added to passthrough_attrib_attrs, so in
pscsi and tcmu - the users of passthrough_parse_cdb() - the attribute
is not available to change parser's behavior.

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
---
 drivers/target/target_core_configfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index ff82b21fdcce..d8589bb39c53 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1203,6 +1203,7 @@ struct configfs_attribute *passthrough_attrib_attrs[] = {
 	&attr_hw_block_size,
 	&attr_hw_max_sectors,
 	&attr_hw_queue_depth,
+	&attr_emulate_pr,
 	&attr_alua_support,
 	&attr_pgr_support,
 	NULL,
-- 
2.12.3

[PATCH 2/4] target: tcmu: add attrbutes enforce_pr_isids and force_pr_aptpl

[Bodo Stroesser]

tcmu has not set TRANSPORT_FLAG_PASSTHROUGH_PGR. Therefore the
in core pr emulation is active by default, but there are some
attributes for configuration missing. So we add them now.

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
---
 drivers/target/target_core_configfs.c | 11 +++++++++++
 drivers/target/target_core_user.c     | 19 +++++++++----------
 include/target/target_core_backend.h  |  1 +
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index d8589bb39c53..efa92d836946 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1210,6 +1210,17 @@ struct configfs_attribute *passthrough_attrib_attrs[] = {
 };
 EXPORT_SYMBOL(passthrough_attrib_attrs);
 
+/*
+ * pr related dev_attrib attributes for devices passing through CDBs,
+ * but allowing in core pr emulation.
+ */
+struct configfs_attribute *passthrough_pr_attrib_attrs[] = {
+	&attr_enforce_pr_isids,
+	&attr_force_pr_aptpl,
+	NULL,
+};
+EXPORT_SYMBOL(passthrough_pr_attrib_attrs);
+
 TB_CIT_SETUP_DRV(dev_attrib, NULL, NULL);
 TB_CIT_SETUP_DRV(dev_action, NULL, NULL);
 
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index f769bb1e3735..8adde343182f 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2753,12 +2753,12 @@ static int __init tcmu_module_init(void)
 		goto out_unreg_device;
 	}
 
-	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
+	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
 		len += sizeof(struct configfs_attribute *);
-	}
-	for (i = 0; tcmu_attrib_attrs[i] != NULL; i++) {
+	for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
+		len += sizeof(struct configfs_attribute *);
+	for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
 		len += sizeof(struct configfs_attribute *);
-	}
 	len += sizeof(struct configfs_attribute *);
 
 	tcmu_attrs = kzalloc(len, GFP_KERNEL);
@@ -2767,13 +2767,12 @@ static int __init tcmu_module_init(void)
 		goto out_unreg_genl;
 	}
 
-	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
+	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
 		tcmu_attrs[i] = passthrough_attrib_attrs[i];
-	}
-	for (k = 0; tcmu_attrib_attrs[k] != NULL; k++) {
-		tcmu_attrs[i] = tcmu_attrib_attrs[k];
-		i++;
-	}
+	for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
+		tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
+	for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
+		tcmu_attrs[i++] = tcmu_attrib_attrs[k];
 	tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
 
 	ret = transport_backend_register(&tcmu_ops);
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 1b752d8ea529..8177667eba6d 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -94,6 +94,7 @@ int	transport_set_vpd_ident(struct t10_vpd *, unsigned char *);
 
 extern struct configfs_attribute *sbc_attrib_attrs[];
 extern struct configfs_attribute *passthrough_attrib_attrs[];
+extern struct configfs_attribute *passthrough_pr_attrib_attrs[];
 
 /* core helpers also used by command snooping in pscsi */
 void	*transport_kmap_data_sg(struct se_cmd *);
-- 
2.12.3

[PATCH 2/4] target: tcmu: add attrbutes enforce_pr_isids and force_pr_aptpl

[Bodo Stroesser]

tcmu has not set TRANSPORT_FLAG_PASSTHROUGH_PGR. Therefore the
in core pr emulation is active by default, but there are some
attributes for configuration missing. So we add them now.

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
---
 drivers/target/target_core_configfs.c | 11 +++++++++++
 drivers/target/target_core_user.c     | 19 +++++++++----------
 include/target/target_core_backend.h  |  1 +
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index d8589bb39c53..efa92d836946 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1210,6 +1210,17 @@ struct configfs_attribute *passthrough_attrib_attrs[] = {
 };
 EXPORT_SYMBOL(passthrough_attrib_attrs);
 
+/*
+ * pr related dev_attrib attributes for devices passing through CDBs,
+ * but allowing in core pr emulation.
+ */
+struct configfs_attribute *passthrough_pr_attrib_attrs[] = {
+	&attr_enforce_pr_isids,
+	&attr_force_pr_aptpl,
+	NULL,
+};
+EXPORT_SYMBOL(passthrough_pr_attrib_attrs);
+
 TB_CIT_SETUP_DRV(dev_attrib, NULL, NULL);
 TB_CIT_SETUP_DRV(dev_action, NULL, NULL);
 
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index f769bb1e3735..8adde343182f 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2753,12 +2753,12 @@ static int __init tcmu_module_init(void)
 		goto out_unreg_device;
 	}
 
-	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
+	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
 		len += sizeof(struct configfs_attribute *);
-	}
-	for (i = 0; tcmu_attrib_attrs[i] != NULL; i++) {
+	for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
+		len += sizeof(struct configfs_attribute *);
+	for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
 		len += sizeof(struct configfs_attribute *);
-	}
 	len += sizeof(struct configfs_attribute *);
 
 	tcmu_attrs = kzalloc(len, GFP_KERNEL);
@@ -2767,13 +2767,12 @@ static int __init tcmu_module_init(void)
 		goto out_unreg_genl;
 	}
 
-	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
+	for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
 		tcmu_attrs[i] = passthrough_attrib_attrs[i];
-	}
-	for (k = 0; tcmu_attrib_attrs[k] != NULL; k++) {
-		tcmu_attrs[i] = tcmu_attrib_attrs[k];
-		i++;
-	}
+	for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
+		tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
+	for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
+		tcmu_attrs[i++] = tcmu_attrib_attrs[k];
 	tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
 
 	ret = transport_backend_register(&tcmu_ops);
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 1b752d8ea529..8177667eba6d 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -94,6 +94,7 @@ int	transport_set_vpd_ident(struct t10_vpd *, unsigned char *);
 
 extern struct configfs_attribute *sbc_attrib_attrs[];
 extern struct configfs_attribute *passthrough_attrib_attrs[];
+extern struct configfs_attribute *passthrough_pr_attrib_attrs[];
 
 /* core helpers also used by command snooping in pscsi */
 void	*transport_kmap_data_sg(struct se_cmd *);
-- 
2.12.3

[PATCH 3/4] target: make transport_flags per device

[Bodo Stroesser]

pgr_support and alua_support device attributes show the
inverted value of the transport_flags
 * TRANSPORT_FLAG_PASSTHROUGH_PGR
 * TRANSPORT_FLAG_PASSTHROUGH_ALUA

These attributes are per device, while the flags are per
backend. So we rename the transport_flags in backend/transport
to transport_flags_default and use its value to initialize
the new transport_flags field in the se_device structure.

Now data and attribute both are per se_device.

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
---
 drivers/target/target_core_alua.c      | 10 +++++-----
 drivers/target/target_core_configfs.c  | 14 +++++++-------
 drivers/target/target_core_device.c    |  3 ++-
 drivers/target/target_core_pr.c        |  2 +-
 drivers/target/target_core_pscsi.c     |  6 +++---
 drivers/target/target_core_tpg.c       |  3 +--
 drivers/target/target_core_transport.c |  6 +++---
 drivers/target/target_core_user.c      |  2 +-
 include/target/target_core_backend.h   |  2 +-
 include/target/target_core_base.h      |  1 +
 10 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index 385e4cf9cfa6..6b72afee2f8b 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -677,7 +677,7 @@ target_alua_state_check(struct se_cmd *cmd)
 
 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
 		return 0;
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
 		return 0;
 
 	/*
@@ -1090,7 +1090,7 @@ int core_alua_do_port_transition(
 	struct t10_alua_tg_pt_gp *tg_pt_gp;
 	int primary, valid_states, rc = 0;
 
-	if (l_dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
+	if (l_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
 		return -ENODEV;
 
 	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
@@ -1920,7 +1920,7 @@ ssize_t core_alua_store_tg_pt_gp_info(
 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
 	int move = 0;
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 		return -ENODEV;
 
@@ -2177,7 +2177,7 @@ ssize_t core_alua_store_offline_bit(
 	unsigned long tmp;
 	int ret;
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 		return -ENODEV;
 
@@ -2263,7 +2263,7 @@ ssize_t core_alua_store_secondary_write_metadata(
 
 int core_setup_alua(struct se_device *dev)
 {
-	if (!(dev->transport->transport_flags &
+	if (!(dev->transport_flags &
 	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
 		struct t10_alua_lu_gp_member *lu_gp_mem;
diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index efa92d836946..279989e32e64 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1099,7 +1099,7 @@ static ssize_t block_size_store(struct config_item *item,
 static ssize_t alua_support_show(struct config_item *item, char *page)
 {
 	struct se_dev_attrib *da = to_attrib(item);
-	u8 flags = da->da_dev->transport->transport_flags;
+	u8 flags = da->da_dev->transport_flags;
 
 	return snprintf(page, PAGE_SIZE, "%d\n",
 			flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ? 0 : 1);
@@ -1108,7 +1108,7 @@ static ssize_t alua_support_show(struct config_item *item, char *page)
 static ssize_t pgr_support_show(struct config_item *item, char *page)
 {
 	struct se_dev_attrib *da = to_attrib(item);
-	u8 flags = da->da_dev->transport->transport_flags;
+	u8 flags = da->da_dev->transport_flags;
 
 	return snprintf(page, PAGE_SIZE, "%d\n",
 			flags & TRANSPORT_FLAG_PASSTHROUGH_PGR ? 0 : 1);
@@ -1654,7 +1654,7 @@ static ssize_t target_pr_res_holder_show(struct config_item *item, char *page)
 	if (!dev->dev_attrib.emulate_pr)
 		return sprintf(page, "SPC_RESERVATIONS_DISABLED\n");
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
 		return sprintf(page, "Passthrough\n");
 
 	spin_lock(&dev->dev_reservation_lock);
@@ -1796,7 +1796,7 @@ static ssize_t target_pr_res_type_show(struct config_item *item, char *page)
 
 	if (!dev->dev_attrib.emulate_pr)
 		return sprintf(page, "SPC_RESERVATIONS_DISABLED\n");
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
 		return sprintf(page, "SPC_PASSTHROUGH\n");
 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
 		return sprintf(page, "SPC2_RESERVATIONS\n");
@@ -1810,7 +1810,7 @@ static ssize_t target_pr_res_aptpl_active_show(struct config_item *item,
 	struct se_device *dev = pr_to_dev(item);
 
 	if (!dev->dev_attrib.emulate_pr ||
-	    (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
+	    (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
 		return 0;
 
 	return sprintf(page, "APTPL Bit Status: %s\n",
@@ -1823,7 +1823,7 @@ static ssize_t target_pr_res_aptpl_metadata_show(struct config_item *item,
 	struct se_device *dev = pr_to_dev(item);
 
 	if (!dev->dev_attrib.emulate_pr ||
-	    (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
+	    (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
 		return 0;
 
 	return sprintf(page, "Ready to process PR APTPL metadata..\n");
@@ -1870,7 +1870,7 @@ static ssize_t target_pr_res_aptpl_metadata_store(struct config_item *item,
 	u8 type = 0;
 
 	if (!dev->dev_attrib.emulate_pr ||
-	    (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
+	    (dev->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 4cee1138284b..d5800cf22df7 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -732,6 +732,7 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
 
 	dev->se_hba = hba;
 	dev->transport = hba->backend->ops;
+	dev->transport_flags = dev->transport->transport_flags_default;
 	dev->prot_length = sizeof(struct t10_pi_tuple);
 	dev->hba_index = hba->hba_index;
 
@@ -1100,7 +1101,7 @@ passthrough_parse_cdb(struct se_cmd *cmd,
 	 * emulate the response, since tcmu does not have the information
 	 * required to process these commands.
 	 */
-	if (!(dev->transport->transport_flags &
+	if (!(dev->transport_flags &
 	      TRANSPORT_FLAG_PASSTHROUGH_PGR)) {
 		if (cdb[0] = PERSISTENT_RESERVE_IN) {
 			cmd->execute_cmd = target_scsi3_emulate_pr_in;
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 5e931690e697..91e41cc55704 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -4086,7 +4086,7 @@ target_check_reservation(struct se_cmd *cmd)
 		return 0;
 	if (!dev->dev_attrib.emulate_pr)
 		return 0;
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
+	if (dev->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 c9d92b3e777d..4e37fa9b409d 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -1070,9 +1070,9 @@ static void pscsi_req_done(struct request *req, blk_status_t status)
 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_PGR,
+	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH |
+				   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,
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c
index d24e0a3ba3ff..62aa5fa63ac0 100644
--- a/drivers/target/target_core_tpg.c
+++ b/drivers/target/target_core_tpg.c
@@ -582,8 +582,7 @@ int core_tpg_add_lun(
 	if (ret)
 		goto out_kill_ref;
 
-	if (!(dev->transport->transport_flags &
-	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
+	if (!(dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 		target_attach_tg_pt_gp(lun, dev->t10_alua.default_tg_pt_gp);
 
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 594b724bbf79..e6b448f43071 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1397,7 +1397,7 @@ transport_check_alloc_task_attr(struct se_cmd *cmd)
 	 * Check if SAM Task Attribute emulation is enabled for this
 	 * struct se_device storage object
 	 */
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
 		return 0;
 
 	if (cmd->sam_task_attr = TCM_ACA_TAG) {
@@ -2012,7 +2012,7 @@ static bool target_handle_task_attr(struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
 		return false;
 
 	cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
@@ -2126,7 +2126,7 @@ static void transport_complete_task_attr(struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
 		return;
 
 	if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 8adde343182f..264f19ba8453 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2617,7 +2617,7 @@ static struct configfs_attribute *tcmu_action_attrs[] = {
 static struct target_backend_ops tcmu_ops = {
 	.name			= "user",
 	.owner			= THIS_MODULE,
-	.transport_flags	= TRANSPORT_FLAG_PASSTHROUGH,
+	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
 	.attach_hba		= tcmu_attach_hba,
 	.detach_hba		= tcmu_detach_hba,
 	.alloc_device		= tcmu_alloc_device,
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 8177667eba6d..959163504f82 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -23,7 +23,7 @@ struct target_backend_ops {
 	char inquiry_rev[4];
 	struct module *owner;
 
-	u8 transport_flags;
+	u8 transport_flags_default;
 
 	int (*attach_hba)(struct se_hba *, u32);
 	void (*detach_hba)(struct se_hba *);
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 6d4a694f6ea7..18c3f277b770 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -772,6 +772,7 @@ struct se_device {
 #define DF_USING_UDEV_PATH			0x00000008
 #define DF_USING_ALIAS				0x00000010
 #define DF_READ_ONLY				0x00000020
+	u8			transport_flags;
 	/* Physical device queue depth */
 	u32			queue_depth;
 	/* Used for SPC-2 reservations enforce of ISIDs */
-- 
2.12.3

[PATCH 3/4] target: make transport_flags per device

[Bodo Stroesser]

pgr_support and alua_support device attributes show the
inverted value of the transport_flags
 * TRANSPORT_FLAG_PASSTHROUGH_PGR
 * TRANSPORT_FLAG_PASSTHROUGH_ALUA

These attributes are per device, while the flags are per
backend. So we rename the transport_flags in backend/transport
to transport_flags_default and use its value to initialize
the new transport_flags field in the se_device structure.

Now data and attribute both are per se_device.

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
---
 drivers/target/target_core_alua.c      | 10 +++++-----
 drivers/target/target_core_configfs.c  | 14 +++++++-------
 drivers/target/target_core_device.c    |  3 ++-
 drivers/target/target_core_pr.c        |  2 +-
 drivers/target/target_core_pscsi.c     |  6 +++---
 drivers/target/target_core_tpg.c       |  3 +--
 drivers/target/target_core_transport.c |  6 +++---
 drivers/target/target_core_user.c      |  2 +-
 include/target/target_core_backend.h   |  2 +-
 include/target/target_core_base.h      |  1 +
 10 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index 385e4cf9cfa6..6b72afee2f8b 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -677,7 +677,7 @@ target_alua_state_check(struct se_cmd *cmd)
 
 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
 		return 0;
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
 		return 0;
 
 	/*
@@ -1090,7 +1090,7 @@ int core_alua_do_port_transition(
 	struct t10_alua_tg_pt_gp *tg_pt_gp;
 	int primary, valid_states, rc = 0;
 
-	if (l_dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
+	if (l_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
 		return -ENODEV;
 
 	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
@@ -1920,7 +1920,7 @@ ssize_t core_alua_store_tg_pt_gp_info(
 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
 	int move = 0;
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 		return -ENODEV;
 
@@ -2177,7 +2177,7 @@ ssize_t core_alua_store_offline_bit(
 	unsigned long tmp;
 	int ret;
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 		return -ENODEV;
 
@@ -2263,7 +2263,7 @@ ssize_t core_alua_store_secondary_write_metadata(
 
 int core_setup_alua(struct se_device *dev)
 {
-	if (!(dev->transport->transport_flags &
+	if (!(dev->transport_flags &
 	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
 		struct t10_alua_lu_gp_member *lu_gp_mem;
diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index efa92d836946..279989e32e64 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1099,7 +1099,7 @@ static ssize_t block_size_store(struct config_item *item,
 static ssize_t alua_support_show(struct config_item *item, char *page)
 {
 	struct se_dev_attrib *da = to_attrib(item);
-	u8 flags = da->da_dev->transport->transport_flags;
+	u8 flags = da->da_dev->transport_flags;
 
 	return snprintf(page, PAGE_SIZE, "%d\n",
 			flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ? 0 : 1);
@@ -1108,7 +1108,7 @@ static ssize_t alua_support_show(struct config_item *item, char *page)
 static ssize_t pgr_support_show(struct config_item *item, char *page)
 {
 	struct se_dev_attrib *da = to_attrib(item);
-	u8 flags = da->da_dev->transport->transport_flags;
+	u8 flags = da->da_dev->transport_flags;
 
 	return snprintf(page, PAGE_SIZE, "%d\n",
 			flags & TRANSPORT_FLAG_PASSTHROUGH_PGR ? 0 : 1);
@@ -1654,7 +1654,7 @@ static ssize_t target_pr_res_holder_show(struct config_item *item, char *page)
 	if (!dev->dev_attrib.emulate_pr)
 		return sprintf(page, "SPC_RESERVATIONS_DISABLED\n");
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
 		return sprintf(page, "Passthrough\n");
 
 	spin_lock(&dev->dev_reservation_lock);
@@ -1796,7 +1796,7 @@ static ssize_t target_pr_res_type_show(struct config_item *item, char *page)
 
 	if (!dev->dev_attrib.emulate_pr)
 		return sprintf(page, "SPC_RESERVATIONS_DISABLED\n");
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
 		return sprintf(page, "SPC_PASSTHROUGH\n");
 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
 		return sprintf(page, "SPC2_RESERVATIONS\n");
@@ -1810,7 +1810,7 @@ static ssize_t target_pr_res_aptpl_active_show(struct config_item *item,
 	struct se_device *dev = pr_to_dev(item);
 
 	if (!dev->dev_attrib.emulate_pr ||
-	    (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
+	    (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
 		return 0;
 
 	return sprintf(page, "APTPL Bit Status: %s\n",
@@ -1823,7 +1823,7 @@ static ssize_t target_pr_res_aptpl_metadata_show(struct config_item *item,
 	struct se_device *dev = pr_to_dev(item);
 
 	if (!dev->dev_attrib.emulate_pr ||
-	    (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
+	    (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
 		return 0;
 
 	return sprintf(page, "Ready to process PR APTPL metadata..\n");
@@ -1870,7 +1870,7 @@ static ssize_t target_pr_res_aptpl_metadata_store(struct config_item *item,
 	u8 type = 0;
 
 	if (!dev->dev_attrib.emulate_pr ||
-	    (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR))
+	    (dev->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 4cee1138284b..d5800cf22df7 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -732,6 +732,7 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
 
 	dev->se_hba = hba;
 	dev->transport = hba->backend->ops;
+	dev->transport_flags = dev->transport->transport_flags_default;
 	dev->prot_length = sizeof(struct t10_pi_tuple);
 	dev->hba_index = hba->hba_index;
 
@@ -1100,7 +1101,7 @@ passthrough_parse_cdb(struct se_cmd *cmd,
 	 * emulate the response, since tcmu does not have the information
 	 * required to process these commands.
 	 */
-	if (!(dev->transport->transport_flags &
+	if (!(dev->transport_flags &
 	      TRANSPORT_FLAG_PASSTHROUGH_PGR)) {
 		if (cdb[0] == PERSISTENT_RESERVE_IN) {
 			cmd->execute_cmd = target_scsi3_emulate_pr_in;
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 5e931690e697..91e41cc55704 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -4086,7 +4086,7 @@ target_check_reservation(struct se_cmd *cmd)
 		return 0;
 	if (!dev->dev_attrib.emulate_pr)
 		return 0;
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
+	if (dev->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 c9d92b3e777d..4e37fa9b409d 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -1070,9 +1070,9 @@ static void pscsi_req_done(struct request *req, blk_status_t status)
 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_PGR,
+	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH |
+				   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,
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c
index d24e0a3ba3ff..62aa5fa63ac0 100644
--- a/drivers/target/target_core_tpg.c
+++ b/drivers/target/target_core_tpg.c
@@ -582,8 +582,7 @@ int core_tpg_add_lun(
 	if (ret)
 		goto out_kill_ref;
 
-	if (!(dev->transport->transport_flags &
-	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
+	if (!(dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 		target_attach_tg_pt_gp(lun, dev->t10_alua.default_tg_pt_gp);
 
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 594b724bbf79..e6b448f43071 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1397,7 +1397,7 @@ transport_check_alloc_task_attr(struct se_cmd *cmd)
 	 * Check if SAM Task Attribute emulation is enabled for this
 	 * struct se_device storage object
 	 */
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
 		return 0;
 
 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
@@ -2012,7 +2012,7 @@ static bool target_handle_task_attr(struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
 		return false;
 
 	cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
@@ -2126,7 +2126,7 @@ static void transport_complete_task_attr(struct se_cmd *cmd)
 {
 	struct se_device *dev = cmd->se_dev;
 
-	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
 		return;
 
 	if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 8adde343182f..264f19ba8453 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2617,7 +2617,7 @@ static struct configfs_attribute *tcmu_action_attrs[] = {
 static struct target_backend_ops tcmu_ops = {
 	.name			= "user",
 	.owner			= THIS_MODULE,
-	.transport_flags	= TRANSPORT_FLAG_PASSTHROUGH,
+	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
 	.attach_hba		= tcmu_attach_hba,
 	.detach_hba		= tcmu_detach_hba,
 	.alloc_device		= tcmu_alloc_device,
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 8177667eba6d..959163504f82 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -23,7 +23,7 @@ struct target_backend_ops {
 	char inquiry_rev[4];
 	struct module *owner;
 
-	u8 transport_flags;
+	u8 transport_flags_default;
 
 	int (*attach_hba)(struct se_hba *, u32);
 	void (*detach_hba)(struct se_hba *);
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 6d4a694f6ea7..18c3f277b770 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -772,6 +772,7 @@ struct se_device {
 #define DF_USING_UDEV_PATH			0x00000008
 #define DF_USING_ALIAS				0x00000010
 #define DF_READ_ONLY				0x00000020
+	u8			transport_flags;
 	/* Physical device queue depth */
 	u32			queue_depth;
 	/* Used for SPC-2 reservations enforce of ISIDs */
-- 
2.12.3

[PATCH 4/4] target: tcmu: make pgr_support and alua_support attributes writable

[Bodo Stroesser]

Currently in tcmu reservation commands are handled by core's
pr implementation (default) or completely rejected (emulate_pr
set to 0). We additionally want to be able to do full
reservation handling in userspace. Therefore we need a way to
set the TRANSPORT_FLAG_PASSTHROUGH_PGR.
The inverted flag is displayed by attribute pgr_support.
Since we moved the flag from transport/backend to se_device in
the previous patch, we now can make it changeable per device by
allowing to write the attribute.
The new field transport_flags_changeable in transport/backend
is used to reject writing if not allowed for a backend.

Regarding ALUA we also want to be able to passthrough commands
to userspace in tcmu. Therefore we need
TRANSPORT_FLAG_PASSTHROUGH_ALUA to be changeable, because
by setting it we can switch off all ALUA checks in core. So we
also set TRANSPORT_FLAG_PASSTHROUGH_ALUA in tcmu's
transport_flags_changeable.

Of course, ALUA and reservation handling in userspace will work
only, if session/nexus information is sent to userspace along with
every command. This will be object of a patch series announced
by Mike Christie.

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
---
 drivers/target/target_core_configfs.c | 56 +++++++++++++++++++++++++++++++++--
 drivers/target/target_core_user.c     |  2 ++
 include/target/target_core_backend.h  |  1 +
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 279989e32e64..f04352285155 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1105,6 +1105,32 @@ static ssize_t alua_support_show(struct config_item *item, char *page)
 			flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ? 0 : 1);
 }
 
+static ssize_t alua_support_store(struct config_item *item,
+		const char *page, size_t count)
+{
+	struct se_dev_attrib *da = to_attrib(item);
+	struct se_device *dev = da->da_dev;
+	bool flag;
+	int ret;
+
+	if (!(dev->transport->transport_flags_changeable &
+	      TRANSPORT_FLAG_PASSTHROUGH_ALUA)) {
+		pr_err("dev[%p]: Unable to change SE Device alua_support:"
+			" alua_support has fixed value\n", dev);
+		return -EINVAL;
+	}
+
+	ret = strtobool(page, &flag);
+	if (ret < 0)
+		return ret;
+
+	if (flag)
+		dev->transport_flags &= ~TRANSPORT_FLAG_PASSTHROUGH_ALUA;
+	else
+		dev->transport_flags |= TRANSPORT_FLAG_PASSTHROUGH_ALUA;
+	return count;
+}
+
 static ssize_t pgr_support_show(struct config_item *item, char *page)
 {
 	struct se_dev_attrib *da = to_attrib(item);
@@ -1114,6 +1140,32 @@ static ssize_t pgr_support_show(struct config_item *item, char *page)
 			flags & TRANSPORT_FLAG_PASSTHROUGH_PGR ? 0 : 1);
 }
 
+static ssize_t pgr_support_store(struct config_item *item,
+		const char *page, size_t count)
+{
+	struct se_dev_attrib *da = to_attrib(item);
+	struct se_device *dev = da->da_dev;
+	bool flag;
+	int ret;
+
+	if (!(dev->transport->transport_flags_changeable &
+	      TRANSPORT_FLAG_PASSTHROUGH_PGR)) {
+		pr_err("dev[%p]: Unable to change SE Device pgr_support:"
+			" pgr_support has fixed value\n", dev);
+		return -EINVAL;
+	}
+
+	ret = strtobool(page, &flag);
+	if (ret < 0)
+		return ret;
+
+	if (flag)
+		dev->transport_flags &= ~TRANSPORT_FLAG_PASSTHROUGH_PGR;
+	else
+		dev->transport_flags |= TRANSPORT_FLAG_PASSTHROUGH_PGR;
+	return count;
+}
+
 CONFIGFS_ATTR(, emulate_model_alias);
 CONFIGFS_ATTR(, emulate_dpo);
 CONFIGFS_ATTR(, emulate_fua_write);
@@ -1146,8 +1198,8 @@ CONFIGFS_ATTR(, unmap_granularity);
 CONFIGFS_ATTR(, unmap_granularity_alignment);
 CONFIGFS_ATTR(, unmap_zeroes_data);
 CONFIGFS_ATTR(, max_write_same_len);
-CONFIGFS_ATTR_RO(, alua_support);
-CONFIGFS_ATTR_RO(, pgr_support);
+CONFIGFS_ATTR(, alua_support);
+CONFIGFS_ATTR(, pgr_support);
 
 /*
  * dev_attrib attributes for devices using the target core SBC/SPC
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 264f19ba8453..b02760b2e9c0 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2618,6 +2618,8 @@ static struct target_backend_ops tcmu_ops = {
 	.name			= "user",
 	.owner			= THIS_MODULE,
 	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
+	.transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
+	                              TRANSPORT_FLAG_PASSTHROUGH_ALUA,
 	.attach_hba		= tcmu_attach_hba,
 	.detach_hba		= tcmu_detach_hba,
 	.alloc_device		= tcmu_alloc_device,
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 959163504f82..f51452e3b984 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -24,6 +24,7 @@ struct target_backend_ops {
 	struct module *owner;
 
 	u8 transport_flags_default;
+	u8 transport_flags_changeable;
 
 	int (*attach_hba)(struct se_hba *, u32);
 	void (*detach_hba)(struct se_hba *);
-- 
2.12.3

[PATCH 4/4] target: tcmu: make pgr_support and alua_support attributes writable

[Bodo Stroesser]

Currently in tcmu reservation commands are handled by core's
pr implementation (default) or completely rejected (emulate_pr
set to 0). We additionally want to be able to do full
reservation handling in userspace. Therefore we need a way to
set the TRANSPORT_FLAG_PASSTHROUGH_PGR.
The inverted flag is displayed by attribute pgr_support.
Since we moved the flag from transport/backend to se_device in
the previous patch, we now can make it changeable per device by
allowing to write the attribute.
The new field transport_flags_changeable in transport/backend
is used to reject writing if not allowed for a backend.

Regarding ALUA we also want to be able to passthrough commands
to userspace in tcmu. Therefore we need
TRANSPORT_FLAG_PASSTHROUGH_ALUA to be changeable, because
by setting it we can switch off all ALUA checks in core. So we
also set TRANSPORT_FLAG_PASSTHROUGH_ALUA in tcmu's
transport_flags_changeable.

Of course, ALUA and reservation handling in userspace will work
only, if session/nexus information is sent to userspace along with
every command. This will be object of a patch series announced
by Mike Christie.

Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
---
 drivers/target/target_core_configfs.c | 56 +++++++++++++++++++++++++++++++++--
 drivers/target/target_core_user.c     |  2 ++
 include/target/target_core_backend.h  |  1 +
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 279989e32e64..f04352285155 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1105,6 +1105,32 @@ static ssize_t alua_support_show(struct config_item *item, char *page)
 			flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ? 0 : 1);
 }
 
+static ssize_t alua_support_store(struct config_item *item,
+		const char *page, size_t count)
+{
+	struct se_dev_attrib *da = to_attrib(item);
+	struct se_device *dev = da->da_dev;
+	bool flag;
+	int ret;
+
+	if (!(dev->transport->transport_flags_changeable &
+	      TRANSPORT_FLAG_PASSTHROUGH_ALUA)) {
+		pr_err("dev[%p]: Unable to change SE Device alua_support:"
+			" alua_support has fixed value\n", dev);
+		return -EINVAL;
+	}
+
+	ret = strtobool(page, &flag);
+	if (ret < 0)
+		return ret;
+
+	if (flag)
+		dev->transport_flags &= ~TRANSPORT_FLAG_PASSTHROUGH_ALUA;
+	else
+		dev->transport_flags |= TRANSPORT_FLAG_PASSTHROUGH_ALUA;
+	return count;
+}
+
 static ssize_t pgr_support_show(struct config_item *item, char *page)
 {
 	struct se_dev_attrib *da = to_attrib(item);
@@ -1114,6 +1140,32 @@ static ssize_t pgr_support_show(struct config_item *item, char *page)
 			flags & TRANSPORT_FLAG_PASSTHROUGH_PGR ? 0 : 1);
 }
 
+static ssize_t pgr_support_store(struct config_item *item,
+		const char *page, size_t count)
+{
+	struct se_dev_attrib *da = to_attrib(item);
+	struct se_device *dev = da->da_dev;
+	bool flag;
+	int ret;
+
+	if (!(dev->transport->transport_flags_changeable &
+	      TRANSPORT_FLAG_PASSTHROUGH_PGR)) {
+		pr_err("dev[%p]: Unable to change SE Device pgr_support:"
+			" pgr_support has fixed value\n", dev);
+		return -EINVAL;
+	}
+
+	ret = strtobool(page, &flag);
+	if (ret < 0)
+		return ret;
+
+	if (flag)
+		dev->transport_flags &= ~TRANSPORT_FLAG_PASSTHROUGH_PGR;
+	else
+		dev->transport_flags |= TRANSPORT_FLAG_PASSTHROUGH_PGR;
+	return count;
+}
+
 CONFIGFS_ATTR(, emulate_model_alias);
 CONFIGFS_ATTR(, emulate_dpo);
 CONFIGFS_ATTR(, emulate_fua_write);
@@ -1146,8 +1198,8 @@ CONFIGFS_ATTR(, unmap_granularity);
 CONFIGFS_ATTR(, unmap_granularity_alignment);
 CONFIGFS_ATTR(, unmap_zeroes_data);
 CONFIGFS_ATTR(, max_write_same_len);
-CONFIGFS_ATTR_RO(, alua_support);
-CONFIGFS_ATTR_RO(, pgr_support);
+CONFIGFS_ATTR(, alua_support);
+CONFIGFS_ATTR(, pgr_support);
 
 /*
  * dev_attrib attributes for devices using the target core SBC/SPC
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 264f19ba8453..b02760b2e9c0 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2618,6 +2618,8 @@ static struct target_backend_ops tcmu_ops = {
 	.name			= "user",
 	.owner			= THIS_MODULE,
 	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
+	.transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
+	                              TRANSPORT_FLAG_PASSTHROUGH_ALUA,
 	.attach_hba		= tcmu_attach_hba,
 	.detach_hba		= tcmu_detach_hba,
 	.alloc_device		= tcmu_alloc_device,
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 959163504f82..f51452e3b984 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -24,6 +24,7 @@ struct target_backend_ops {
 	struct module *owner;
 
 	u8 transport_flags_default;
+	u8 transport_flags_changeable;
 
 	int (*attach_hba)(struct se_hba *, u32);
 	void (*detach_hba)(struct se_hba *);
-- 
2.12.3

Re: [PATCH 0/4] target: tcmu: allow flexible pr and alua handling

[Mike Christie]

On 4/27/20 10:08 AM, Bodo Stroesser wrote:
> These patches already were sent to target-devel only. So I'm resending
> them now, slightly modified according to review comments from
> target-devel.
> 
> The goal of the patches is to add more flexibility to tcmu regarding
> PGR handling.
> 
> Since the attribute emulate_pr is missing for pscsi in the same way as
> for tcmu, I'm adding it to pscsi also. 
>

It looks ok to me.

Reviewed-by: Mike Christie <mchristi@redhat.com>

Re: [PATCH 0/4] target: tcmu: allow flexible pr and alua handling

[Mike Christie]

On 4/27/20 10:08 AM, Bodo Stroesser wrote:
> These patches already were sent to target-devel only. So I'm resending
> them now, slightly modified according to review comments from
> target-devel.
> 
> The goal of the patches is to add more flexibility to tcmu regarding
> PGR handling.
> 
> Since the attribute emulate_pr is missing for pscsi in the same way as
> for tcmu, I'm adding it to pscsi also. 
>

It looks ok to me.

Reviewed-by: Mike Christie <mchristi@redhat.com>

Re: [PATCH 1/4] target: add missing emulate_pr attribute to passthrough backends

[Martin K. Petersen]

On Mon, 27 Apr 2020 17:08:20 +0200, Bodo Stroesser wrote:

> In commit b49d6f7885306ee636d5c1af52170f3069ccf5f7 the new attribute
> emulate_pr was added.
> passthrough_parse_cdb() uses the attribute's value to distinguish,
> whether reservation commands should be rejected or not.
> But the new attribute was not added to passthrough_attrib_attrs, so in
> pscsi and tcmu - the users of passthrough_parse_cdb() - the attribute
> is not available to change parser's behavior.

Applied to 5.8/scsi-queue, thanks!

[1/4] scsi: target: Add missing emulate_pr attribute to passthrough backends
      https://git.kernel.org/mkp/scsi/c/9299941716a3
[2/4] scsi: target: tcmu: Add attributes enforce_pr_isids and force_pr_aptpl
      https://git.kernel.org/mkp/scsi/c/4703b6252b33
[3/4] scsi: target: Make transport_flags per device
      https://git.kernel.org/mkp/scsi/c/69088a049488
[4/4] scsi: target: tcmu: Make pgr_support and alua_support attributes writable
      https://git.kernel.org/mkp/scsi/c/356ba2a8bc8d

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 1/4] target: add missing emulate_pr attribute to passthrough backends

[Martin K. Petersen]

On Mon, 27 Apr 2020 17:08:20 +0200, Bodo Stroesser wrote:

> In commit b49d6f7885306ee636d5c1af52170f3069ccf5f7 the new attribute
> emulate_pr was added.
> passthrough_parse_cdb() uses the attribute's value to distinguish,
> whether reservation commands should be rejected or not.
> But the new attribute was not added to passthrough_attrib_attrs, so in
> pscsi and tcmu - the users of passthrough_parse_cdb() - the attribute
> is not available to change parser's behavior.

Applied to 5.8/scsi-queue, thanks!

[1/4] scsi: target: Add missing emulate_pr attribute to passthrough backends
      https://git.kernel.org/mkp/scsi/c/9299941716a3
[2/4] scsi: target: tcmu: Add attributes enforce_pr_isids and force_pr_aptpl
      https://git.kernel.org/mkp/scsi/c/4703b6252b33
[3/4] scsi: target: Make transport_flags per device
      https://git.kernel.org/mkp/scsi/c/69088a049488
[4/4] scsi: target: tcmu: Make pgr_support and alua_support attributes writable
      https://git.kernel.org/mkp/scsi/c/356ba2a8bc8d

-- 
Martin K. Petersen	Oracle Linux Engineering