loopback: Add fabric_prot_type attribute support

This patch updates loopback to add a new fabric_prot_type TPG attribute,
used for controlling LLD level protection into LIO when the backend
device does not support T10-PI.

Also, go ahead and set DIN_PASS + DOUT_PASS so target-core knows that
it will be doing any WRITE_STRIP and READ_INSERT operations.

Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 52 insertions, 2 deletions

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index f4618e722187..797c7315f520 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -697,6 +697,13 @@ static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg
         return 0;
 }
 
+static int tcm_loop_check_prot_fabric_only(struct se_portal_group *se_tpg)
+{
+        struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
+                                                   tl_se_tpg);
+        return tl_tpg->tl_fabric_prot_type;
+}
+
 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
         struct se_portal_group *se_tpg)
 {
@@ -912,6 +919,46 @@ static void tcm_loop_port_unlink(
 
 /* End items for tcm_loop_port_cit */
 
+static ssize_t tcm_loop_tpg_attrib_show_fabric_prot_type(
+        struct se_portal_group *se_tpg,
+        char *page)
+{
+        struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
+                                                   tl_se_tpg);
+
+        return sprintf(page, "%d\n", tl_tpg->tl_fabric_prot_type);
+}
+
+static ssize_t tcm_loop_tpg_attrib_store_fabric_prot_type(
+        struct se_portal_group *se_tpg,
+        const char *page,
+        size_t count)
+{
+        struct tcm_loop_tpg *tl_tpg = container_of(se_tpg, struct tcm_loop_tpg,
+                                                   tl_se_tpg);
+        unsigned long val;
+        int ret = kstrtoul(page, 0, &val);
+
+        if (ret) {
+                pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
+                return ret;
+        }
+        if (val != 0 && val != 1 && val != 3) {
+                pr_err("Invalid qla2xxx fabric_prot_type: %lu\n", val);
+                return -EINVAL;
+        }
+        tl_tpg->tl_fabric_prot_type = val;
+
+        return count;
+}
+
+TF_TPG_ATTRIB_ATTR(tcm_loop, fabric_prot_type, S_IRUGO | S_IWUSR);
+
+static struct configfs_attribute *tcm_loop_tpg_attrib_attrs[] = {
+        &tcm_loop_tpg_attrib_fabric_prot_type.attr,
+        NULL,
+};
+
 /* Start items for tcm_loop_nexus_cit */
 
 static int tcm_loop_make_nexus(
@@ -937,7 +984,8 @@ static int tcm_loop_make_nexus(
         /*
          * Initialize the struct se_session pointer
          */
-        tl_nexus->se_sess = transport_init_session(TARGET_PROT_ALL);
+        tl_nexus->se_sess = transport_init_session(
+                                TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS);
         if (IS_ERR(tl_nexus->se_sess)) {
                 ret = PTR_ERR(tl_nexus->se_sess);
                 goto out;
@@ -1377,6 +1425,8 @@ static int tcm_loop_register_configfs(void)
                                         &tcm_loop_check_demo_mode_write_protect;
         fabric->tf_ops.tpg_check_prod_mode_write_protect =
                                         &tcm_loop_check_prod_mode_write_protect;
+        fabric->tf_ops.tpg_check_prot_fabric_only =
+                                        &tcm_loop_check_prot_fabric_only;
         /*
          * The TCM loopback fabric module runs in demo-mode to a local
          * virtual SCSI device, so fabric dependent initator ACLs are
@@ -1429,7 +1479,7 @@ static int tcm_loop_register_configfs(void)
          */
         fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
         fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
-        fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
+        fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = tcm_loop_tpg_attrib_attrs;
         fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
         fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
         /*