Re: [PATCH scsi-misc-2.6 08/13] scsi: move request preps in other places into prep_fn()

From: Tejun Heo (htejun_at_gmail.com)
Date: 03/31/05

  • Next message: Ingo Molnar: "Re: [PATCH 0/5] ppc RT: Realtime preempt support for PPC" 
    To: James.Bottomley@steeleye.com, axboe@suse.de
Date:	Thu, 31 Mar 2005 18:08:30 +0900 (KST)

    08_scsi_move_preps_to_prep_fn.patch

            Move request preparations scattered in scsi_request_fn() and
            scsi_dispatch_cmd() into scsi_prep_fn().

            * CDB_SIZE check in scsi_dispatch_cmd()
            * SCSI-2 LUN preparation in scsi_dispatch_cmd()
            * scsi_init_cmd_errh() in scsi_request_fn()

            No invalid request reaches scsi_request_fn() anymore.

    Signed-off-by: Tejun Heo <htejun@gmail.com>

     scsi.c | 30 ------------------------------
     scsi_lib.c | 25 +++++++++++++++++++------
     2 files changed, 19 insertions(+), 36 deletions(-)

    Index: scsi-export/drivers/scsi/scsi.c
    ===================================================================
    --- scsi-export.orig/drivers/scsi/scsi.c 2005-03-31 18:06:21.000000000 +0900
    +++ scsi-export/drivers/scsi/scsi.c 2005-03-31 18:06:22.000000000 +0900
    @@ -79,15 +79,6 @@
     #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.
      */
    @@ -566,14 +557,6 @@ int scsi_dispatch_cmd(struct scsi_cmnd *
                     goto out;
             }
     
    - /*
    - * If SCSI-2 or lower, store the LUN value in cmnd.
    - */
    - if (cmd->device->scsi_level <= SCSI_2) {
    - cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
    - (cmd->device->lun << 5 & 0xe0);
    - }
    -
             /*
              * We will wait MIN_RESET_DELAY clock ticks after the last reset so
              * we can avoid the drive not being ready.
    @@ -614,19 +597,6 @@ int scsi_dispatch_cmd(struct scsi_cmnd *
     
             atomic_inc(&cmd->device->iorequest_cnt);
     
    - /*
    - * 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) {
    - SCSI_LOG_MLQUEUE(3,
    - printk("queuecommand : command too long.\n"));
    - cmd->result = (DID_ABORT << 16);
    -
    - scsi_done(cmd);
    - goto out;
    - }
    -
             spin_lock_irqsave(host->host_lock, flags);
             scsi_cmd_get_serial(host, cmd);
     
    Index: scsi-export/drivers/scsi/scsi_lib.c
    ===================================================================
    --- scsi-export.orig/drivers/scsi/scsi_lib.c 2005-03-31 18:06:21.000000000 +0900
    +++ scsi-export/drivers/scsi/scsi_lib.c 2005-03-31 18:06:22.000000000 +0900
    @@ -28,6 +28,14 @@
     #include "scsi_priv.h"
     #include "scsi_logging.h"
     
    +/*
    + * 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)
     
     #define SG_MEMPOOL_NR (sizeof(scsi_sg_pools)/sizeof(struct scsi_host_sg_pool))
     #define SG_MEMPOOL_SIZE 32
    @@ -1140,6 +1148,17 @@ static int scsi_prep_fn(struct request_q
                             goto kill;
             }
     
    + /* Check command length. */
    + if (CDB_SIZE(cmd) > sdev->host->max_cmd_len)
    + goto kill;
    +
    + scsi_init_cmd_errh(cmd);
    +
    + /* If SCSI-2 or lower, store the LUN value in cmnd. */
    + if (cmd->device->scsi_level <= SCSI_2)
    + cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
    + (cmd->device->lun << 5 & 0xe0);
    +
             /*
              * The request is now prepped, no need to come back here
              */
    @@ -1316,12 +1335,6 @@ static void scsi_request_fn(struct reque
                     }
     
                     /*
    - * Finally, initialize any error handling parameters, and set up
    - * the timers for timeouts.
    - */
    - scsi_init_cmd_errh(cmd);
    -
    - /*
                      * Dispatch the command to the low-level driver.
                      */
                     rtn = scsi_dispatch_cmd(cmd);

    -
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