[SCSI] Prevent scsi_execute_async from guessing cdb length

When the scsi_execute_async interface was added it ended up reducing
the flexibility of userspace to send arbitrary scsi commands through
sg using SG_IO. The SG_IO interface allows userspace to specify the
CDB length. This is now ignored in scsi_execute_async and it is
guessed using the COMMAND_SIZE macro, which is not always correct,
particularly for vendor specific commands. This patch adds a cmd_len
parameter to the scsi_execute_async interface to allow the caller
to specify the length of the CDB.

Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 3574ba935af8..4a602853a98e 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -436,6 +436,7 @@ free_bios:
  * scsi_execute_async - insert request
  * @sdev:       scsi device
  * @cmd:        scsi command
+ * @cmd_len:    length of scsi cdb
  * @data_direction: data direction
  * @buffer:     data buffer (this can be a kernel buffer or scatterlist)
  * @bufflen:    len of buffer
@@ -445,7 +446,7 @@ free_bios:
  * @flags:      or into request flags
  **/
 int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
-                       int data_direction, void *buffer, unsigned bufflen,
+                       int cmd_len, int data_direction, void *buffer, unsigned bufflen,
                        int use_sg, int timeout, int retries, void *privdata,
                        void (*done)(void *, char *, int, int), gfp_t gfp)
 {
@@ -472,7 +473,7 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
         if (err)
                 goto free_req;
 
-        req->cmd_len = COMMAND_SIZE(cmd[0]);
+        req->cmd_len = cmd_len;
         memcpy(req->cmd, cmd, req->cmd_len);
         req->sense = sioc->sense;
         req->sense_len = 0;