[SCSI] add support for variable length extended commands

Add support for variable-length, extended, and vendor specific
CDBs to scsi-ml. It is now possible for initiators and ULD's
to issue these types of commands. LLDs need not change much.
All they need is to raise the .max_cmd_len to the longest command
they support (see iscsi patch).

- clean-up some code paths that did not expect commands to be
  larger than 16, and change cmd_len members' type to short as
  char is not enough.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

3 files changed, 8 insertions, 19 deletions

diff --git a/drivers/scsi/constants.c b/drivers/scsi/constants.c
index 403a7f2d8f9b..9785d7384199 100644
--- a/drivers/scsi/constants.c
+++ b/drivers/scsi/constants.c
@@ -28,7 +28,6 @@
 #define SERVICE_ACTION_OUT_12 0xa9
 #define SERVICE_ACTION_IN_16 0x9e
 #define SERVICE_ACTION_OUT_16 0x9f
-#define VARIABLE_LENGTH_CMD 0x7f
 
 
 
@@ -210,7 +209,7 @@ static void print_opcode_name(unsigned char * cdbp, int cdb_len)
         cdb0 = cdbp[0];
         switch(cdb0) {
         case VARIABLE_LENGTH_CMD:
-                len = cdbp[7] + 8;
+                len = scsi_varlen_cdb_length(cdbp);
                 if (len < 10) {
                         printk("short variable length command, "
                                "len=%d ext_len=%d", len, cdb_len);
@@ -300,7 +299,7 @@ static void print_opcode_name(unsigned char * cdbp, int cdb_len)
         cdb0 = cdbp[0];
         switch(cdb0) {
         case VARIABLE_LENGTH_CMD:
-                len = cdbp[7] + 8;
+                len = scsi_varlen_cdb_length(cdbp);
                 if (len < 10) {
                         printk("short opcode=0x%x command, len=%d "
                                "ext_len=%d", cdb0, len, cdb_len);
@@ -335,10 +334,7 @@ void __scsi_print_command(unsigned char *cdb)
         int k, len;
 
         print_opcode_name(cdb, 0);
-        if (VARIABLE_LENGTH_CMD == cdb[0])
-                len = cdb[7] + 8;
-        else
-                len = COMMAND_SIZE(cdb[0]);
+        len = scsi_command_size(cdb);
         /* print out all bytes in cdb */
         for (k = 0; k < len; ++k) 
                 printk(" %02x", cdb[k]);
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 749c9c7fc2e1..110e776d1a07 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -79,15 +79,6 @@ static void scsi_done(struct scsi_cmnd *cmd);
 #define MIN_RESET_PERIOD (15*HZ)
 
 /*
- * Macro to determine the size of SCSI command. This macro takes vendor
- * unique commands into account. SCSI commands in groups 6 and 7 are
- * vendor unique and we will depend upon the command length being
- * supplied correctly in cmd_len.
- */
-#define CDB_SIZE(cmd)   (((((cmd)->cmnd[0] >> 5) & 7) < 6) ? \
-                                COMMAND_SIZE((cmd)->cmnd[0]) : (cmd)->cmd_len)
-
-/*
  * Note - the initial logging level can be set here to log events at boot time.
  * After the system is up, you may enable logging via the /proc interface.
  */
@@ -709,9 +700,11 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
          * Before we queue this command, check if the command
          * length exceeds what the host adapter can handle.
          */
-        if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) {
+        if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
                 SCSI_LOG_MLQUEUE(3,
-                                printk("queuecommand : command too long.\n"));
+                        printk("queuecommand : command too long. "
+                               "cdb_size=%d host->max_cmd_len=%d\n",
+                               cmd->cmd_len, cmd->device->host->max_cmd_len));
                 cmd->result = (DID_ABORT << 16);
 
                 scsi_done(cmd);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 325270b520e1..ba7e8ad76d04 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -445,7 +445,7 @@ static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
         scsi_set_resid(cmd, 0);
         memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
         if (cmd->cmd_len == 0)
-                cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
+                cmd->cmd_len = scsi_command_size(cmd->cmnd);
 }
 
 void scsi_device_unbusy(struct scsi_device *sdev)