[SCSI] libiscsi, iscsi_tcp, iser: add session cmds array accessor

Currently to get a ctask from the session cmd array, you have to
know to use the itt modifier. To make this easier on LLDs and
so in the future we can easilly kill the session array and use
the host shared map instead, this patch adds a nice wrapper
to strip the itt into a session->cmds index and return a ctask.

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

1 files changed, 9 insertions, 4 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index dfaf9fa57340..f2a08f7ed902 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -740,7 +740,6 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
         struct iscsi_session *session = conn->session;
         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
         struct iscsi_cmd_task *ctask;
-        uint32_t itt;
 
         /* verify PDU length */
         tcp_conn->in.datalen = ntoh24(hdr->dlength);
@@ -758,7 +757,7 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 
         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
         /* verify itt (itt encoding: age+cid+itt) */
-        rc = iscsi_verify_itt(conn, hdr, &itt);
+        rc = iscsi_verify_itt(conn, hdr->itt);
         if (rc)
                 return rc;
 
@@ -767,7 +766,10 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 
         switch(opcode) {
         case ISCSI_OP_SCSI_DATA_IN:
-                ctask = session->cmds[itt];
+                ctask = iscsi_itt_to_ctask(conn, hdr->itt);
+                if (!ctask)
+                        return ISCSI_ERR_BAD_ITT;
+
                 spin_lock(&conn->session->lock);
                 rc = iscsi_data_rsp(conn, ctask);
                 spin_unlock(&conn->session->lock);
@@ -810,7 +812,10 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
                 rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
                 break;
         case ISCSI_OP_R2T:
-                ctask = session->cmds[itt];
+                ctask = iscsi_itt_to_ctask(conn, hdr->itt);
+                if (!ctask)
+                        return ISCSI_ERR_BAD_ITT;
+
                 if (ahslen)
                         rc = ISCSI_ERR_AHSLEN;
                 else if (ctask->sc->sc_data_direction == DMA_TO_DEVICE) {