[SCSI] libiscsi: fix session age rollover and remove cid encoding

The session age mask is only 4 bits, but session->age is 32. When
it gets larger then 15 and we try to or the bits some bits get
dropped and the check for session age in iscsi_verify_itt is useless.

The ISCSI_CID_MASK related bits are also useless since cid is always
one.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

3 files changed, 6 insertions, 14 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 10ba76285852..59f8445eab0d 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -160,7 +160,7 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
         hdr->opcode = ISCSI_OP_SCSI_CMD;
         hdr->flags = ISCSI_ATTR_SIMPLE;
         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
-        hdr->itt = build_itt(ctask->itt, conn->id, session->age);
+        hdr->itt = build_itt(ctask->itt, session->age);
         hdr->data_length = cpu_to_be32(scsi_bufflen(sc));
         hdr->cmdsn = cpu_to_be32(session->cmdsn);
         session->cmdsn++;
@@ -705,14 +705,6 @@ int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
                         return ISCSI_ERR_BAD_ITT;
                 }
 
-                if (((__force u32)hdr->itt & ISCSI_CID_MASK) !=
-                    (conn->id << ISCSI_CID_SHIFT)) {
-                        iscsi_conn_printk(KERN_ERR, conn,
-                                          "iscsi: received itt %x, expected "
-                                          "CID (%x)\n",
-                                          (__force u32)hdr->itt, conn->id);
-                        return ISCSI_ERR_BAD_ITT;
-                }
                 itt = get_itt(hdr->itt);
         } else
                 itt = ~0U;
@@ -776,7 +768,7 @@ static void iscsi_prep_mtask(struct iscsi_conn *conn,
          */
         nop->cmdsn = cpu_to_be32(session->cmdsn);
         if (hdr->itt != RESERVED_ITT) {
-                hdr->itt = build_itt(mtask->itt, conn->id, session->age);
+                hdr->itt = build_itt(mtask->itt, session->age);
                 /*
                  * TODO: We always use immediate, so we never hit this.
                  * If we start to send tmfs or nops as non-immediate then
@@ -2036,6 +2028,8 @@ int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
                 conn->stop_stage = 0;
                 conn->tmf_state = TMF_INITIAL;
                 session->age++;
+                if (session->age == 16)
+                        session->age = 0;
                 break;
         case STOP_CONN_TERM:
                 conn->stop_stage = 0;
diff --git a/include/scsi/iscsi_proto.h b/include/scsi/iscsi_proto.h
index 318a909e7ae1..5ffec8ad6964 100644
--- a/include/scsi/iscsi_proto.h
+++ b/include/scsi/iscsi_proto.h
@@ -45,8 +45,8 @@
 /* initiator tags; opaque for target */
 typedef uint32_t __bitwise__ itt_t;
 /* below makes sense only for initiator that created this tag */
-#define build_itt(itt, id, age) ((__force itt_t)\
-        ((itt) | ((id) << ISCSI_CID_SHIFT) | ((age) << ISCSI_AGE_SHIFT)))
+#define build_itt(itt, age) ((__force itt_t)\
+        ((itt) | ((age) << ISCSI_AGE_SHIFT)))
 #define get_itt(itt) ((__force uint32_t)(itt_t)(itt) & ISCSI_ITT_MASK)
 #define RESERVED_ITT ((__force itt_t)0xffffffff)
 
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 5784e4ff8edc..7b90b63fb5c7 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -70,8 +70,6 @@ enum {
 #define ISCSI_SUSPEND_BIT               1
 
 #define ISCSI_ITT_MASK                  (0xfff)
-#define ISCSI_CID_SHIFT                 12
-#define ISCSI_CID_MASK                  (0xffff << ISCSI_CID_SHIFT)
 #define ISCSI_AGE_SHIFT                 28
 #define ISCSI_AGE_MASK                  (0xf << ISCSI_AGE_SHIFT)