[PATCH 2/4] block layer varlen-cdb

[Boaz Harrosh <bharrosh@panasas.com>]

  - add varlen_cdb and varlen_cdb_len to hold a large user cdb
    if needed. They start as empty. Allocation of buffer must
    be done by user and held until request execution is done.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
---
 block/ll_rw_blk.c      |    2 ++
 include/linux/blkdev.h |    7 ++++++-
 2 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index b01dee3..df478f2 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -261,6 +261,8 @@ static void rq_init(struct request_queue *q, struct request *rq)
 	rq->end_io_data = NULL;
 	rq->completion_data = NULL;
 	rq->next_rq = NULL;
+	rq->varlen_cdb_len = 0;
+	rq->varlen_cdb = NULL;
 }
 
 /**
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index bbf906a..990643d 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -287,8 +287,13 @@ struct request {
 	/*
 	 * when request is used as a packet command carrier
 	 */
-	unsigned int cmd_len;
+	unsigned short cmd_len;
+	unsigned short varlen_cdb_len;  /* length of varlen_cdb buffer */
 	unsigned char cmd[BLK_MAX_CDB];
+	unsigned char *varlen_cdb;      /* an optional variable-length cdb.
+	                                 * points to a user buffer that must be
+	                                 * valid until end of request
+	                                 */
 
 	unsigned int data_len;
 	unsigned int sense_len;
-- 
1.5.3.1