tcm_loop: Implement transport offline

Add attribute 'transport_status' to simulate link failure.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 56 insertions, 1 deletions

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 21b49f351723..a00ad27940b7 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -178,7 +178,10 @@ static void tcm_loop_submission_work(struct work_struct *work)
                 set_host_byte(sc, DID_NO_CONNECT);
                 goto out_done;
         }
-
+        if (tl_tpg->tl_transport_status == TCM_TRANSPORT_OFFLINE) {
+                set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
+                goto out_done;
+        }
         tl_nexus = tl_hba->tl_nexus;
         if (!tl_nexus) {
                 scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
@@ -1064,8 +1067,56 @@ check_newline:
 
 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
 
+static ssize_t tcm_loop_tpg_show_transport_status(
+        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);
+        const char *status = NULL;
+        ssize_t ret = -EINVAL;
+
+        switch (tl_tpg->tl_transport_status) {
+        case TCM_TRANSPORT_ONLINE:
+                status = "online";
+                break;
+        case TCM_TRANSPORT_OFFLINE:
+                status = "offline";
+                break;
+        default:
+                break;
+        }
+
+        if (status)
+                ret = snprintf(page, PAGE_SIZE, "%s\n", status);
+
+        return ret;
+}
+
+static ssize_t tcm_loop_tpg_store_transport_status(
+        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);
+
+        if (!strncmp(page, "online", 6)) {
+                tl_tpg->tl_transport_status = TCM_TRANSPORT_ONLINE;
+                return count;
+        }
+        if (!strncmp(page, "offline", 7)) {
+                tl_tpg->tl_transport_status = TCM_TRANSPORT_OFFLINE;
+                return count;
+        }
+        return -EINVAL;
+}
+
+TF_TPG_BASE_ATTR(tcm_loop, transport_status, S_IRUGO | S_IWUSR);
+
 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
         &tcm_loop_tpg_nexus.attr,
+        &tcm_loop_tpg_transport_status.attr,
         NULL,
 };
 
diff --git a/drivers/target/loopback/tcm_loop.h b/drivers/target/loopback/tcm_loop.h
index dd7a84ee78e1..56528f7dafae 100644
--- a/drivers/target/loopback/tcm_loop.h
+++ b/drivers/target/loopback/tcm_loop.h
@@ -40,8 +40,12 @@ struct tcm_loop_nacl {
         struct se_node_acl se_node_acl;
 };
 
+#define TCM_TRANSPORT_ONLINE 0
+#define TCM_TRANSPORT_OFFLINE 1
+
 struct tcm_loop_tpg {
         unsigned short tl_tpgt;
+        unsigned short tl_transport_status;
         atomic_t tl_tpg_port_count;
         struct se_portal_group tl_se_tpg;
         struct tcm_loop_hba *tl_hba;