[SCSI] iscsi: extended cdb support

Support for extended CDBs in iscsi.
All we need is to check if command spills over 16 bytes then allocate
an iscsi-extended-header for the leftovers.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Reviewed-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/include/scsi/iscsi_proto.h b/include/scsi/iscsi_proto.h
index 5ffec8ad6964..e0593bfae622 100644
--- a/include/scsi/iscsi_proto.h
+++ b/include/scsi/iscsi_proto.h
@@ -112,6 +112,7 @@ struct iscsi_ahs_hdr {
 
 #define ISCSI_AHSTYPE_CDB               1
 #define ISCSI_AHSTYPE_RLENGTH           2
+#define ISCSI_CDB_SIZE                  16
 
 /* iSCSI PDU Header */
 struct iscsi_cmd {
@@ -125,7 +126,7 @@ struct iscsi_cmd {
         __be32 data_length;
         __be32 cmdsn;
         __be32 exp_statsn;
-        uint8_t cdb[16];        /* SCSI Command Block */
+        uint8_t cdb[ISCSI_CDB_SIZE];    /* SCSI Command Block */
         /* Additional Data (Command Dependent) */
 };
 
@@ -154,7 +155,8 @@ struct iscsi_ecdb_ahdr {
         __be16 ahslength;       /* CDB length - 15, including reserved byte */
         uint8_t ahstype;
         uint8_t reserved;
-        uint8_t ecdb[260 - 16]; /* 4-byte aligned extended CDB spillover */
+        /* 4-byte aligned extended CDB spillover */
+        uint8_t ecdb[260 - ISCSI_CDB_SIZE];
 };
 
 /* SCSI Response Header */