RELATIVE TARGET PORT IDENTIFIER can be read and configured via configfs:
$ echo 0x10 > $TARGET/tpgt_N/attrib/rtpi
RTPI has to be unique among all target ports, otherwise the write fails.
Configuration of a new RTPI value triggers INQUIRY DATA HAS CHANGED unit
attention as defined in SPC-4 "6.6.1 INQUIRY command introduction":
> If INQUIRY data changes for any reason, the device server shall
> establish a unit attention condition for the initiator port associated
> with every I_T nexus (see SAM-5), with the additional sense code set to
> INQUIRY DATA HAS CHANGED.
Signed-off-by: Roman Bolshakov <r.bolshakov@xxxxxxxxx>
---
drivers/target/target_core_tpg.c | 69 ++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c
index 67474690720d..c0d564f17951 100644
--- a/drivers/target/target_core_tpg.c
+++ b/drivers/target/target_core_tpg.c
@@ -720,6 +720,75 @@ void core_tpg_remove_lun(
percpu_ref_exit(&lun->lun_ref);
}
+/* Set a Unit Attention on all I_T nexuses related to the port */
+static void core_tpg_ua(struct se_portal_group *se_tpg, u8 asc, u8 ascq)
+{
+ struct se_lun *lun;
+ struct se_dev_entry *se_deve;
+
+ mutex_lock(&se_tpg->tpg_lun_mutex);
+ hlist_for_each_entry_rcu(lun, &se_tpg->tpg_lun_hlist, link) {
+ spin_lock(&lun->lun_deve_lock);
+ list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
+ core_scsi3_ua_allocate(se_deve, asc, ascq);
+ spin_unlock(&lun->lun_deve_lock);
+ }
+ mutex_unlock(&se_tpg->tpg_lun_mutex);
+}
+
+static ssize_t core_tpg_rtpi_show(struct config_item *item, char *page)
+{
+ struct se_portal_group *se_tpg = attrib_to_tpg(item);
+
+ return sprintf(page, "%#x\n", se_tpg->tpg_rtpi);
+}
+
+static ssize_t core_tpg_rtpi_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct se_portal_group *se_tpg = attrib_to_tpg(item);
+ struct se_portal_group *tpg;
+ u16 val;
+ int ret;
+
+ ret = kstrtou16(page, 0, &val);
+ if (ret < 0)
+ return ret;
+ if (val == 0)
+ return -EINVAL;
+
+ /* RTPI shouldn't conflict with values of existing ports */
+ ret = mutex_lock_interruptible(&g_tpg_mutex);
+ if (ret < 0)
+ return ret;
+
+ list_for_each_entry(tpg, &g_tpg_list, tpg_list) {
+ if (se_tpg != tpg && val == tpg->tpg_rtpi) {
+ pr_err("TARGET_CORE[%s]->TPG[%u] - RTPI %#x conflicts"
+ " with TARGET_CORE[%s]->TPG[%u]\n",
+ se_tpg->se_tpg_tfo->fabric_name,
+ se_tpg->se_tpg_tfo->tpg_get_tag(tpg),
+ val,
+ tpg->se_tpg_tfo->fabric_name,
+ tpg->se_tpg_tfo->tpg_get_tag(tpg));
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ if (se_tpg->tpg_rtpi != val) {
+ se_tpg->tpg_rtpi = val;
+ core_tpg_ua(se_tpg, 0x3f, ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
+ }
+ ret = count;
+out:
+ mutex_unlock(&g_tpg_mutex);
+ return ret;
+}
+
+CONFIGFS_ATTR(core_tpg_, rtpi);
+
struct configfs_attribute *core_tpg_attrib_attrs[] = {
+ &core_tpg_attr_rtpi,
NULL,
};
--
2.26.1
