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>

diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index b5ba1ec..556ea1b 100644 (file)
--- 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);