target: REPORT LUNS should return LUN 0 even for dynamic ACLs

If an initiator doesn't have any real LUNs assigned, we should report
LUN 0 and a LUN list length of 1.  Some versions of Solaris at least
go beserk if we report a LUN list length of 0.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org> # v3.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 10 insertions, 4 deletions

diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index b5ba1ec3c354..556ea1b2cdd8 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -1221,11 +1221,9 @@ sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd)
          * coming via a target_core_mod PASSTHROUGH op, and not through
          * a $FABRIC_MOD.  In that case, report LUN=0 only.
          */
-        if (!sess) {
-                int_to_scsilun(0, (struct scsi_lun *)&buf[offset]);
-                lun_count = 1;
+        if (!sess)
                 goto done;
-        }
+
         nacl = sess->se_node_acl;
 
         rcu_read_lock();
@@ -1248,6 +1246,14 @@ sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd)
          * See SPC3 r07, page 159.
          */
 done:
+        /*
+         * If no LUNs are accessible, report virtual LUN 0.
+         */
+        if (lun_count == 0) {
+                int_to_scsilun(0, (struct scsi_lun *)&buf[offset]);
+                lun_count = 1;
+        }
+
         lun_count *= 8;
         buf[0] = ((lun_count >> 24) & 0xff);
         buf[1] = ((lun_count >> 16) & 0xff);