[SCSI] libiscsi: fix session age rollover and remove cid encoding
Mike Christie [Thu, 31 Jan 2008 19:36:53 +0000 (13:36 -0600)]
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>

drivers/scsi/libiscsi.c
include/scsi/iscsi_proto.h
include/scsi/libiscsi.h

index 10ba762..59f8445 100644 (file)
@@ -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;
index 318a909..5ffec8a 100644 (file)
@@ -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)
 
index 5784e4f..7b90b63 100644 (file)
@@ -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)