4 files changed, 102 insertions, 12 deletions

diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index be7251ee8b3a..e624b836469c 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -66,18 +66,24 @@ int target_emulate_report_target_port_groups(struct se_cmd *cmd)
         struct t10_alua_tg_pt_gp *tg_pt_gp;
         struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
         unsigned char *buf;
-        u32 rd_len = 0, off = 4; /* Skip over RESERVED area to first
-                                    Target port group descriptor */
+        u32 rd_len = 0, off;
+        int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
         /*
-         * Need at least 4 bytes of response data or else we can't
-         * even fit the return data length.
+         * Skip over RESERVED area to first Target port group descriptor
+         * depending on the PARAMETER DATA FORMAT type..
          */
-        if (cmd->data_length < 4) {
-                pr_warn("REPORT TARGET PORT GROUPS allocation length %u"
-                        " too small\n", cmd->data_length);
+        if (ext_hdr != 0)
+                off = 8;
+        else
+                off = 4;
+
+        if (cmd->data_length < off) {
+                pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
+                        " small for %s header\n", cmd->data_length,
+                        (ext_hdr) ? "extended" : "normal");
+                cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
                 return -EINVAL;
         }
-
         buf = transport_kmap_data_sg(cmd);
 
         spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
@@ -158,11 +164,31 @@ int target_emulate_report_target_port_groups(struct se_cmd *cmd)
         /*
          * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
          */
-        buf[0] = ((rd_len >> 24) & 0xff);
-        buf[1] = ((rd_len >> 16) & 0xff);
-        buf[2] = ((rd_len >> 8) & 0xff);
-        buf[3] = (rd_len & 0xff);
+        put_unaligned_be32(rd_len, &buf[0]);
 
+        /*
+         * Fill in the Extended header parameter data format if requested
+         */
+        if (ext_hdr != 0) {
+                buf[4] = 0x10;
+                /*
+                 * Set the implict transition time (in seconds) for the application
+                 * client to use as a base for it's transition timeout value.
+                 *
+                 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
+                 * this CDB was received upon to determine this value individually
+                 * for ALUA target port group.
+                 */
+                port = cmd->se_lun->lun_sep;
+                tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
+                if (tg_pt_gp_mem) {
+                        spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+                        tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
+                        if (tg_pt_gp)
+                                buf[5] = tg_pt_gp->tg_pt_gp_implict_trans_secs;
+                        spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+                }
+        }
         transport_kunmap_data_sg(cmd);
 
         target_complete_cmd(cmd, GOOD);
@@ -1355,6 +1381,7 @@ struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
          */
         tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
         tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
+        tg_pt_gp->tg_pt_gp_implict_trans_secs = ALUA_DEFAULT_IMPLICT_TRANS_SECS;
 
         if (def_group) {
                 spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
@@ -1851,6 +1878,37 @@ ssize_t core_alua_store_trans_delay_msecs(
         return count;
 }
 
+ssize_t core_alua_show_implict_trans_secs(
+        struct t10_alua_tg_pt_gp *tg_pt_gp,
+        char *page)
+{
+        return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implict_trans_secs);
+}
+
+ssize_t core_alua_store_implict_trans_secs(
+        struct t10_alua_tg_pt_gp *tg_pt_gp,
+        const char *page,
+        size_t count)
+{
+        unsigned long tmp;
+        int ret;
+
+        ret = strict_strtoul(page, 0, &tmp);
+        if (ret < 0) {
+                pr_err("Unable to extract implict_trans_secs\n");
+                return -EINVAL;
+        }
+        if (tmp > ALUA_MAX_IMPLICT_TRANS_SECS) {
+                pr_err("Passed implict_trans_secs: %lu, exceeds"
+                        " ALUA_MAX_IMPLICT_TRANS_SECS: %d\n", tmp,
+                        ALUA_MAX_IMPLICT_TRANS_SECS);
+                return  -EINVAL;
+        }
+        tg_pt_gp->tg_pt_gp_implict_trans_secs = (int)tmp;
+
+        return count;
+}
+
 ssize_t core_alua_show_preferred_bit(
         struct t10_alua_tg_pt_gp *tg_pt_gp,
         char *page)
diff --git a/drivers/target/target_core_alua.h b/drivers/target/target_core_alua.h
index e26454324752..f920c170d47b 100644
--- a/drivers/target/target_core_alua.h
+++ b/drivers/target/target_core_alua.h
@@ -52,6 +52,12 @@
 #define ALUA_DEFAULT_TRANS_DELAY_MSECS                  0
 #define ALUA_MAX_TRANS_DELAY_MSECS                      30000 /* 30 seconds */
 /*
+ * Used for the recommended application client implict transition timeout
+ * in seconds, returned by the REPORT_TARGET_PORT_GROUPS w/ extended header.
+ */
+#define ALUA_DEFAULT_IMPLICT_TRANS_SECS                 0
+#define ALUA_MAX_IMPLICT_TRANS_SECS                     255
+/*
  * Used by core_alua_update_tpg_primary_metadata() and
  * core_alua_update_tpg_secondary_metadata()
  */
@@ -107,6 +113,10 @@ extern ssize_t core_alua_show_trans_delay_msecs(struct t10_alua_tg_pt_gp *,
                                         char *);
 extern ssize_t core_alua_store_trans_delay_msecs(struct t10_alua_tg_pt_gp *,
                                         const char *, size_t);
+extern ssize_t core_alua_show_implict_trans_secs(struct t10_alua_tg_pt_gp *,
+                                        char *);
+extern ssize_t core_alua_store_implict_trans_secs(struct t10_alua_tg_pt_gp *,
+                                        const char *, size_t);
 extern ssize_t core_alua_show_preferred_bit(struct t10_alua_tg_pt_gp *,
                                         char *);
 extern ssize_t core_alua_store_preferred_bit(struct t10_alua_tg_pt_gp *,
diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 931521cc4e4f..801efa892046 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -2447,6 +2447,26 @@ static ssize_t target_core_alua_tg_pt_gp_store_attr_trans_delay_msecs(
 SE_DEV_ALUA_TG_PT_ATTR(trans_delay_msecs, S_IRUGO | S_IWUSR);
 
 /*
+ * implict_trans_secs
+ */
+static ssize_t target_core_alua_tg_pt_gp_show_attr_implict_trans_secs(
+        struct t10_alua_tg_pt_gp *tg_pt_gp,
+        char *page)
+{
+        return core_alua_show_implict_trans_secs(tg_pt_gp, page);
+}
+
+static ssize_t target_core_alua_tg_pt_gp_store_attr_implict_trans_secs(
+        struct t10_alua_tg_pt_gp *tg_pt_gp,
+        const char *page,
+        size_t count)
+{
+        return core_alua_store_implict_trans_secs(tg_pt_gp, page, count);
+}
+
+SE_DEV_ALUA_TG_PT_ATTR(implict_trans_secs, S_IRUGO | S_IWUSR);
+
+/*
  * preferred
  */
 
@@ -2570,6 +2590,7 @@ static struct configfs_attribute *target_core_alua_tg_pt_gp_attrs[] = {
         &target_core_alua_tg_pt_gp_alua_write_metadata.attr,
         &target_core_alua_tg_pt_gp_nonop_delay_msecs.attr,
         &target_core_alua_tg_pt_gp_trans_delay_msecs.attr,
+        &target_core_alua_tg_pt_gp_implict_trans_secs.attr,
         &target_core_alua_tg_pt_gp_preferred.attr,
         &target_core_alua_tg_pt_gp_tg_pt_gp_id.attr,
         &target_core_alua_tg_pt_gp_members.attr,
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 1fe9111f4dc1..dc35d8660aa6 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -330,6 +330,7 @@ struct t10_alua_tg_pt_gp {
         int     tg_pt_gp_alua_access_type;
         int     tg_pt_gp_nonop_delay_msecs;
         int     tg_pt_gp_trans_delay_msecs;
+        int     tg_pt_gp_implict_trans_secs;
         int     tg_pt_gp_pref;
         int     tg_pt_gp_write_metadata;
         /* Used by struct t10_alua_tg_pt_gp->tg_pt_gp_md_buf_len */