]> nv-tegra.nvidia Code Review - linux-3.10.git/blobdiff - drivers/scsi/scsi_error.c
[SCSI] Handle disk devices which can not process medium access commands
[linux-3.10.git] / drivers / scsi / scsi_error.c
index f49feb9351d085ad8cd9f49d162bb73fcce70755..2cfcbffa41fd559b075e7c75eae57e2c7f637488 100644 (file)
@@ -3,19 +3,20 @@
  *
  *  SCSI error/timeout handling
  *      Initial versions: Eric Youngdale.  Based upon conversations with
- *                        Leonard Zubkoff and David Miller at Linux Expo, 
+ *                        Leonard Zubkoff and David Miller at Linux Expo,
  *                        ideas originating from all over the place.
  *
  *     Restructured scsi_unjam_host and associated functions.
  *     September 04, 2002 Mike Anderson (andmike@us.ibm.com)
  *
  *     Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
- *     minor  cleanups.
+ *     minor cleanups.
  *     September 30, 2002 Mike Anderson (andmike@us.ibm.com)
  */
 
 #include <linux/module.h>
 #include <linux/sched.h>
+#include <linux/gfp.h>
 #include <linux/timer.h>
 #include <linux/string.h>
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
 #include <linux/blkdev.h>
 #include <linux/delay.h>
-#include <linux/scatterlist.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_dbg.h>
 #include <scsi/scsi_device.h>
+#include <scsi/scsi_driver.h>
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_transport.h>
 #include <scsi/scsi_host.h>
@@ -39,6 +40,8 @@
 #include "scsi_logging.h"
 #include "scsi_transport_api.h"
 
+#include <trace/events/scsi.h>
+
 #define SENSE_TIMEOUT          (10*HZ)
 
 /*
 #define BUS_RESET_SETTLE_TIME   (10)
 #define HOST_RESET_SETTLE_TIME  (10)
 
+static int scsi_eh_try_stu(struct scsi_cmnd *scmd);
+
 /* called with shost->host_lock held */
 void scsi_eh_wakeup(struct Scsi_Host *shost)
 {
        if (shost->host_busy == shost->host_failed) {
+               trace_scsi_eh_wakeup(shost);
                wake_up_process(shost->ehandler);
                SCSI_LOG_ERROR_RECOVERY(5,
                                printk("Waking error handler thread\n"));
@@ -63,7 +69,7 @@ void scsi_eh_wakeup(struct Scsi_Host *shost)
  * @shost:     SCSI host to invoke error handling on.
  *
  * Schedule SCSI EH without scmd.
- **/
+ */
 void scsi_schedule_eh(struct Scsi_Host *shost)
 {
        unsigned long flags;
@@ -87,7 +93,7 @@ EXPORT_SYMBOL_GPL(scsi_schedule_eh);
  *
  * Return value:
  *     0 on failure.
- **/
+ */
 int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
 {
        struct Scsi_Host *shost = scmd->device->host;
@@ -112,107 +118,37 @@ int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
        return ret;
 }
 
-/**
- * scsi_add_timer - Start timeout timer for a single scsi command.
- * @scmd:      scsi command that is about to start running.
- * @timeout:   amount of time to allow this command to run.
- * @complete:  timeout function to call if timer isn't canceled.
- *
- * Notes:
- *    This should be turned into an inline function.  Each scsi command
- *    has its own timer, and as it is added to the queue, we set up the
- *    timer.  When the command completes, we cancel the timer.
- **/
-void scsi_add_timer(struct scsi_cmnd *scmd, int timeout,
-                   void (*complete)(struct scsi_cmnd *))
-{
-
-       /*
-        * If the clock was already running for this command, then
-        * first delete the timer.  The timer handling code gets rather
-        * confused if we don't do this.
-        */
-       if (scmd->eh_timeout.function)
-               del_timer(&scmd->eh_timeout);
-
-       scmd->eh_timeout.data = (unsigned long)scmd;
-       scmd->eh_timeout.expires = jiffies + timeout;
-       scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
-
-       SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
-                                         " %d, (%p)\n", __FUNCTION__,
-                                         scmd, timeout, complete));
-
-       add_timer(&scmd->eh_timeout);
-}
-
-/**
- * scsi_delete_timer - Delete/cancel timer for a given function.
- * @scmd:      Cmd that we are canceling timer for
- *
- * Notes:
- *     This should be turned into an inline function.
- *
- * Return value:
- *     1 if we were able to detach the timer.  0 if we blew it, and the
- *     timer function has already started to run.
- **/
-int scsi_delete_timer(struct scsi_cmnd *scmd)
-{
-       int rtn;
-
-       rtn = del_timer(&scmd->eh_timeout);
-
-       SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
-                                        " rtn: %d\n", __FUNCTION__,
-                                        scmd, rtn));
-
-       scmd->eh_timeout.data = (unsigned long)NULL;
-       scmd->eh_timeout.function = NULL;
-
-       return rtn;
-}
-
 /**
  * scsi_times_out - Timeout function for normal scsi commands.
- * @scmd:      Cmd that is timing out.
+ * @req:       request that is timing out.
  *
  * Notes:
  *     We do not need to lock this.  There is the potential for a race
  *     only in that the normal completion handling might run, but if the
  *     normal completion function determines that the timer has already
  *     fired, then it mustn't do anything.
- **/
-void scsi_times_out(struct scsi_cmnd *scmd)
+ */
+enum blk_eh_timer_return scsi_times_out(struct request *req)
 {
-       enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
+       struct scsi_cmnd *scmd = req->special;
+       enum blk_eh_timer_return rtn = BLK_EH_NOT_HANDLED;
+       struct Scsi_Host *host = scmd->device->host;
 
+       trace_scsi_dispatch_cmd_timeout(scmd);
        scsi_log_completion(scmd, TIMEOUT_ERROR);
 
-       if (scmd->device->host->transportt->eh_timed_out)
-               eh_timed_out = scmd->device->host->transportt->eh_timed_out;
-       else if (scmd->device->host->hostt->eh_timed_out)
-               eh_timed_out = scmd->device->host->hostt->eh_timed_out;
-       else
-               eh_timed_out = NULL;
-
-       if (eh_timed_out)
-               switch (eh_timed_out(scmd)) {
-               case EH_HANDLED:
-                       __scsi_done(scmd);
-                       return;
-               case EH_RESET_TIMER:
-                       scsi_add_timer(scmd, scmd->timeout_per_command,
-                                      scsi_times_out);
-                       return;
-               case EH_NOT_HANDLED:
-                       break;
-               }
+       if (host->transportt->eh_timed_out)
+               rtn = host->transportt->eh_timed_out(scmd);
+       else if (host->hostt->eh_timed_out)
+               rtn = host->hostt->eh_timed_out(scmd);
 
-       if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
-               scmd->result |= DID_TIME_OUT << 16;
-               __scsi_done(scmd);
-       }
+       scmd->result |= DID_TIME_OUT << 16;
+
+       if (unlikely(rtn == BLK_EH_NOT_HANDLED &&
+                    !scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD)))
+               rtn = BLK_EH_HANDLED;
+
+       return rtn;
 }
 
 /**
@@ -225,7 +161,7 @@ void scsi_times_out(struct scsi_cmnd *scmd)
  *
  * Return value:
  *     0 when dev was taken offline by error recovery. 1 OK to proceed.
- **/
+ */
 int scsi_block_when_processing_errors(struct scsi_device *sdev)
 {
        int online;
@@ -234,7 +170,7 @@ int scsi_block_when_processing_errors(struct scsi_device *sdev)
 
        online = scsi_device_online(sdev);
 
-       SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__,
+       SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __func__,
                                          online));
 
        return online;
@@ -246,7 +182,7 @@ EXPORT_SYMBOL(scsi_block_when_processing_errors);
  * scsi_eh_prt_fail_stats - Log info on failures.
  * @shost:     scsi host being recovered.
  * @work_q:    Queue of scsi cmds to process.
- **/
+ */
 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
                                          struct list_head *work_q)
 {
@@ -263,7 +199,7 @@ static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
                                ++total_failures;
                                if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
                                        ++cmd_cancel;
-                               else 
+                               else
                                        ++cmd_failed;
                        }
                }
@@ -272,7 +208,7 @@ static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
                        SCSI_LOG_ERROR_RECOVERY(3,
                                sdev_printk(KERN_INFO, sdev,
                                            "%s: cmds failed: %d, cancel: %d\n",
-                                           __FUNCTION__, cmd_failed,
+                                           __func__, cmd_failed,
                                            cmd_cancel));
                        cmd_cancel = 0;
                        cmd_failed = 0;
@@ -282,7 +218,7 @@ static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
 
        SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
                                          " devices require eh work\n",
-                                 total_failures, devices_failed));
+                                  total_failures, devices_failed));
 }
 #endif
 
@@ -291,14 +227,15 @@ static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
  * @scmd:      Cmd to have sense checked.
  *
  * Return value:
- *     SUCCESS or FAILED or NEEDS_RETRY
+ *     SUCCESS or FAILED or NEEDS_RETRY or TARGET_ERROR
  *
  * Notes:
  *     When a deferred error is detected the current command has
  *     not been executed and needs retrying.
- **/
+ */
 static int scsi_check_sense(struct scsi_cmnd *scmd)
 {
+       struct scsi_device *sdev = scmd->device;
        struct scsi_sense_hdr sshdr;
 
        if (! scsi_command_normalize_sense(scmd, &sshdr))
@@ -307,6 +244,16 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
        if (scsi_sense_is_deferred(&sshdr))
                return NEEDS_RETRY;
 
+       if (sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh &&
+                       sdev->scsi_dh_data->scsi_dh->check_sense) {
+               int rc;
+
+               rc = sdev->scsi_dh_data->scsi_dh->check_sense(sdev, &sshdr);
+               if (rc != SCSI_RETURN_NOT_HANDLED)
+                       return rc;
+               /* handler does not care. Drop down to default handling */
+       }
+
        /*
         * Previous logic looked for FILEMARK, EOM or ILI which are
         * mainly associated with tapes and returned SUCCESS.
@@ -334,6 +281,9 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
                return /* soft_error */ SUCCESS;
 
        case ABORTED_COMMAND:
+               if (sshdr.asc == 0x10) /* DIF */
+                       return SUCCESS;
+
                return NEEDS_RETRY;
        case NOT_READY:
        case UNIT_ATTENTION:
@@ -344,11 +294,19 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
                 * so that we can deal with it there.
                 */
                if (scmd->device->expecting_cc_ua) {
-                       scmd->device->expecting_cc_ua = 0;
-                       return NEEDS_RETRY;
+                       /*
+                        * Because some device does not queue unit
+                        * attentions correctly, we carefully check
+                        * additional sense code and qualifier so as
+                        * not to squash media change unit attention.
+                        */
+                       if (sshdr.asc != 0x28 || sshdr.ascq != 0x00) {
+                               scmd->device->expecting_cc_ua = 0;
+                               return NEEDS_RETRY;
+                       }
                }
                /*
-                * if the device is in the process of becoming ready, we 
+                * if the device is in the process of becoming ready, we
                 * should retry.
                 */
                if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
@@ -360,36 +318,126 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
                if (scmd->device->allow_restart &&
                    (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
                        return FAILED;
+
+               if (sshdr.asc == 0x3f && sshdr.ascq == 0x0e)
+                       scmd_printk(KERN_WARNING, scmd,
+                                   "Warning! Received an indication that the "
+                                   "LUN assignments on this target have "
+                                   "changed. The Linux SCSI layer does not "
+                                   "automatically remap LUN assignments.\n");
+               else if (sshdr.asc == 0x3f)
+                       scmd_printk(KERN_WARNING, scmd,
+                                   "Warning! Received an indication that the "
+                                   "operating parameters on this target have "
+                                   "changed. The Linux SCSI layer does not "
+                                   "automatically adjust these parameters.\n");
+
+               if (sshdr.asc == 0x38 && sshdr.ascq == 0x07)
+                       scmd_printk(KERN_WARNING, scmd,
+                                   "Warning! Received an indication that the "
+                                   "LUN reached a thin provisioning soft "
+                                   "threshold.\n");
+
+               /*
+                * Pass the UA upwards for a determination in the completion
+                * functions.
+                */
                return SUCCESS;
 
-               /* these three are not supported */
+               /* these are not supported */
        case COPY_ABORTED:
        case VOLUME_OVERFLOW:
        case MISCOMPARE:
-               return SUCCESS;
+       case BLANK_CHECK:
+       case DATA_PROTECT:
+               return TARGET_ERROR;
 
        case MEDIUM_ERROR:
                if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */
                    sshdr.asc == 0x13 || /* AMNF DATA FIELD */
                    sshdr.asc == 0x14) { /* RECORD NOT FOUND */
-                       return SUCCESS;
+                       return TARGET_ERROR;
                }
                return NEEDS_RETRY;
 
        case HARDWARE_ERROR:
                if (scmd->device->retry_hwerror)
-                       return NEEDS_RETRY;
+                       return ADD_TO_MLQUEUE;
                else
-                       return SUCCESS;
+                       return TARGET_ERROR;
 
        case ILLEGAL_REQUEST:
-       case BLANK_CHECK:
-       case DATA_PROTECT:
+               if (sshdr.asc == 0x20 || /* Invalid command operation code */
+                   sshdr.asc == 0x21 || /* Logical block address out of range */
+                   sshdr.asc == 0x24 || /* Invalid field in cdb */
+                   sshdr.asc == 0x26) { /* Parameter value invalid */
+                       return TARGET_ERROR;
+               }
+               return SUCCESS;
+
        default:
                return SUCCESS;
        }
 }
 
+static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
+{
+       struct scsi_host_template *sht = sdev->host->hostt;
+       struct scsi_device *tmp_sdev;
+
+       if (!sht->change_queue_depth ||
+           sdev->queue_depth >= sdev->max_queue_depth)
+               return;
+
+       if (time_before(jiffies,
+           sdev->last_queue_ramp_up + sdev->queue_ramp_up_period))
+               return;
+
+       if (time_before(jiffies,
+           sdev->last_queue_full_time + sdev->queue_ramp_up_period))
+               return;
+
+       /*
+        * Walk all devices of a target and do
+        * ramp up on them.
+        */
+       shost_for_each_device(tmp_sdev, sdev->host) {
+               if (tmp_sdev->channel != sdev->channel ||
+                   tmp_sdev->id != sdev->id ||
+                   tmp_sdev->queue_depth == sdev->max_queue_depth)
+                       continue;
+               /*
+                * call back into LLD to increase queue_depth by one
+                * with ramp up reason code.
+                */
+               sht->change_queue_depth(tmp_sdev, tmp_sdev->queue_depth + 1,
+                                       SCSI_QDEPTH_RAMP_UP);
+               sdev->last_queue_ramp_up = jiffies;
+       }
+}
+
+static void scsi_handle_queue_full(struct scsi_device *sdev)
+{
+       struct scsi_host_template *sht = sdev->host->hostt;
+       struct scsi_device *tmp_sdev;
+
+       if (!sht->change_queue_depth)
+               return;
+
+       shost_for_each_device(tmp_sdev, sdev->host) {
+               if (tmp_sdev->channel != sdev->channel ||
+                   tmp_sdev->id != sdev->id)
+                       continue;
+               /*
+                * We do not know the number of commands that were at
+                * the device when we got the queue full so we start
+                * from the highest possible value and work our way down.
+                */
+               sht->change_queue_depth(tmp_sdev, tmp_sdev->queue_depth - 1,
+                                       SCSI_QDEPTH_QFULL);
+       }
+}
+
 /**
  * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
  * @scmd:      SCSI cmd to examine.
@@ -399,7 +447,7 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
  *    queued during error recovery.  the main difference here is that we
  *    don't allow for the possibility of retries here, and we are a lot
  *    more restrictive about what we consider acceptable.
- **/
+ */
 static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
 {
        /*
@@ -430,6 +478,7 @@ static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
         */
        switch (status_byte(scmd->result)) {
        case GOOD:
+               scsi_handle_queue_ramp_up(scmd->device);
        case COMMAND_TERMINATED:
                return SUCCESS;
        case CHECK_CONDITION:
@@ -441,9 +490,18 @@ static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
                 * who knows?  FIXME(eric)
                 */
                return SUCCESS;
-       case BUSY:
-       case QUEUE_FULL:
        case RESERVATION_CONFLICT:
+               if (scmd->cmnd[0] == TEST_UNIT_READY)
+                       /* it is a success, we probed the device and
+                        * found it */
+                       return SUCCESS;
+               /* otherwise, we failed to send the command */
+               return FAILED;
+       case QUEUE_FULL:
+               scsi_handle_queue_full(scmd->device);
+               /* fall through */
+       case BUSY:
+               return NEEDS_RETRY;
        default:
                return FAILED;
        }
@@ -453,14 +511,14 @@ static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
 /**
  * scsi_eh_done - Completion function for error handling.
  * @scmd:      Cmd that is done.
- **/
+ */
 static void scsi_eh_done(struct scsi_cmnd *scmd)
 {
-       struct completion     *eh_action;
+       struct completion *eh_action;
 
        SCSI_LOG_ERROR_RECOVERY(3,
                printk("%s scmd: %p result: %x\n",
-                       __FUNCTION__, scmd, scmd->result));
+                       __func__, scmd, scmd->result));
 
        eh_action = scmd->device->host->eh_action;
        if (eh_action)
@@ -470,27 +528,28 @@ static void scsi_eh_done(struct scsi_cmnd *scmd)
 /**
  * scsi_try_host_reset - ask host adapter to reset itself
  * @scmd:      SCSI cmd to send hsot reset.
- **/
+ */
 static int scsi_try_host_reset(struct scsi_cmnd *scmd)
 {
        unsigned long flags;
        int rtn;
+       struct Scsi_Host *host = scmd->device->host;
+       struct scsi_host_template *hostt = host->hostt;
 
        SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
-                                         __FUNCTION__));
+                                         __func__));
 
-       if (!scmd->device->host->hostt->eh_host_reset_handler)
+       if (!hostt->eh_host_reset_handler)
                return FAILED;
 
-       rtn = scmd->device->host->hostt->eh_host_reset_handler(scmd);
+       rtn = hostt->eh_host_reset_handler(scmd);
 
        if (rtn == SUCCESS) {
-               if (!scmd->device->host->hostt->skip_settle_delay)
+               if (!hostt->skip_settle_delay)
                        ssleep(HOST_RESET_SETTLE_TIME);
-               spin_lock_irqsave(scmd->device->host->host_lock, flags);
-               scsi_report_bus_reset(scmd->device->host,
-                                     scmd_channel(scmd));
-               spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
+               spin_lock_irqsave(host->host_lock, flags);
+               scsi_report_bus_reset(host, scmd_channel(scmd));
+               spin_unlock_irqrestore(host->host_lock, flags);
        }
 
        return rtn;
@@ -499,130 +558,129 @@ static int scsi_try_host_reset(struct scsi_cmnd *scmd)
 /**
  * scsi_try_bus_reset - ask host to perform a bus reset
  * @scmd:      SCSI cmd to send bus reset.
- **/
+ */
 static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
 {
        unsigned long flags;
        int rtn;
+       struct Scsi_Host *host = scmd->device->host;
+       struct scsi_host_template *hostt = host->hostt;
 
        SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
-                                         __FUNCTION__));
+                                         __func__));
 
-       if (!scmd->device->host->hostt->eh_bus_reset_handler)
+       if (!hostt->eh_bus_reset_handler)
                return FAILED;
 
-       rtn = scmd->device->host->hostt->eh_bus_reset_handler(scmd);
+       rtn = hostt->eh_bus_reset_handler(scmd);
 
        if (rtn == SUCCESS) {
-               if (!scmd->device->host->hostt->skip_settle_delay)
+               if (!hostt->skip_settle_delay)
                        ssleep(BUS_RESET_SETTLE_TIME);
-               spin_lock_irqsave(scmd->device->host->host_lock, flags);
-               scsi_report_bus_reset(scmd->device->host,
-                                     scmd_channel(scmd));
-               spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
+               spin_lock_irqsave(host->host_lock, flags);
+               scsi_report_bus_reset(host, scmd_channel(scmd));
+               spin_unlock_irqrestore(host->host_lock, flags);
        }
 
        return rtn;
 }
 
+static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
+{
+       sdev->was_reset = 1;
+       sdev->expecting_cc_ua = 1;
+}
+
 /**
- * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
- * @scmd:      SCSI cmd used to send BDR
+ * scsi_try_target_reset - Ask host to perform a target reset
+ * @scmd:      SCSI cmd used to send a target reset
  *
  * Notes:
  *    There is no timeout for this operation.  if this operation is
  *    unreliable for a given host, then the host itself needs to put a
  *    timer on it, and set the host back to a consistent state prior to
  *    returning.
- **/
-static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
+ */
+static int scsi_try_target_reset(struct scsi_cmnd *scmd)
 {
+       unsigned long flags;
        int rtn;
+       struct Scsi_Host *host = scmd->device->host;
+       struct scsi_host_template *hostt = host->hostt;
 
-       if (!scmd->device->host->hostt->eh_device_reset_handler)
+       if (!hostt->eh_target_reset_handler)
                return FAILED;
 
-       rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);
+       rtn = hostt->eh_target_reset_handler(scmd);
        if (rtn == SUCCESS) {
-               scmd->device->was_reset = 1;
-               scmd->device->expecting_cc_ua = 1;
+               spin_lock_irqsave(host->host_lock, flags);
+               __starget_for_each_device(scsi_target(scmd->device), NULL,
+                                         __scsi_report_device_reset);
+               spin_unlock_irqrestore(host->host_lock, flags);
        }
 
        return rtn;
 }
 
-static int __scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
+/**
+ * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
+ * @scmd:      SCSI cmd used to send BDR
+ *
+ * Notes:
+ *    There is no timeout for this operation.  if this operation is
+ *    unreliable for a given host, then the host itself needs to put a
+ *    timer on it, and set the host back to a consistent state prior to
+ *    returning.
+ */
+static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
 {
-       if (!scmd->device->host->hostt->eh_abort_handler)
+       int rtn;
+       struct scsi_host_template *hostt = scmd->device->host->hostt;
+
+       if (!hostt->eh_device_reset_handler)
                return FAILED;
 
-       return scmd->device->host->hostt->eh_abort_handler(scmd);
+       rtn = hostt->eh_device_reset_handler(scmd);
+       if (rtn == SUCCESS)
+               __scsi_report_device_reset(scmd->device, NULL);
+       return rtn;
 }
 
-/**
- * scsi_try_to_abort_cmd - Ask host to abort a running command.
- * @scmd:      SCSI cmd to abort from Lower Level.
- *
- * Notes:
- *    This function will not return until the user's completion function
- *    has been called.  there is no timeout on this operation.  if the
- *    author of the low-level driver wishes this operation to be timed,
- *    they can provide this facility themselves.  helper functions in
- *    scsi_error.c can be supplied to make this easier to do.
- **/
-static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
+static int scsi_try_to_abort_cmd(struct scsi_host_template *hostt, struct scsi_cmnd *scmd)
 {
-       /*
-        * scsi_done was called just after the command timed out and before
-        * we had a chance to process it. (db)
-        */
-       if (scmd->serial_number == 0)
-               return SUCCESS;
-       return __scsi_try_to_abort_cmd(scmd);
+       if (!hostt->eh_abort_handler)
+               return FAILED;
+
+       return hostt->eh_abort_handler(scmd);
 }
 
 static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
 {
-       if (__scsi_try_to_abort_cmd(scmd) != SUCCESS)
+       if (scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd) != SUCCESS)
                if (scsi_try_bus_device_reset(scmd) != SUCCESS)
-                       if (scsi_try_bus_reset(scmd) != SUCCESS)
-                               scsi_try_host_reset(scmd);
+                       if (scsi_try_target_reset(scmd) != SUCCESS)
+                               if (scsi_try_bus_reset(scmd) != SUCCESS)
+                                       scsi_try_host_reset(scmd);
 }
 
 /**
- * scsi_send_eh_cmnd  - submit a scsi command as part of error recory
+ * scsi_eh_prep_cmnd  - Save a scsi command info as part of error recory
  * @scmd:       SCSI command structure to hijack
- * @cmnd:       CDB to send
- * @cmnd_size:  size in bytes of @cmnd
- * @timeout:    timeout for this request
- * @copy_sense: request sense data if set to 1
- *
- * This function is used to send a scsi command down to a target device
- * as part of the error recovery process.  If @copy_sense is 0 the command
- * sent must be one that does not transfer any data.  If @copy_sense is 1
- * the command must be REQUEST_SENSE and this functions copies out the
- * sense buffer it got into @scmd->sense_buffer.
- *
- * Return value:
- *    SUCCESS or FAILED or NEEDS_RETRY
- **/
-static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
-                            int cmnd_size, int timeout, int copy_sense)
+ * @ses:        structure to save restore information
+ * @cmnd:       CDB to send. Can be NULL if no new cmnd is needed
+ * @cmnd_size:  size in bytes of @cmnd (must be <= BLK_MAX_CDB)
+ * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
+ *
+ * This function is used to save a scsi command information before re-execution
+ * as part of the error recovery process.  If @sense_bytes is 0 the command
+ * sent must be one that does not transfer any data.  If @sense_bytes != 0
+ * @cmnd is ignored and this functions sets up a REQUEST_SENSE command
+ * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
+ */
+void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
+                       unsigned char *cmnd, int cmnd_size, unsigned sense_bytes)
 {
        struct scsi_device *sdev = scmd->device;
-       struct Scsi_Host *shost = sdev->host;
-       int old_result = scmd->result;
-       DECLARE_COMPLETION_ONSTACK(done);
-       unsigned long timeleft;
-       unsigned long flags;
-       struct scatterlist sgl;
-       unsigned char old_cmnd[MAX_COMMAND_SIZE];
-       enum dma_data_direction old_data_direction;
-       unsigned short old_use_sg;
-       unsigned char old_cmd_len;
-       unsigned old_bufflen;
-       void *old_buffer;
-       int rtn;
 
        /*
         * We need saved copies of a number of fields - this is because
@@ -631,35 +689,44 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
         * we will need to restore these values prior to running the actual
         * command.
         */
-       old_buffer = scmd->request_buffer;
-       old_bufflen = scmd->request_bufflen;
-       memcpy(old_cmnd, scmd->cmnd, sizeof(scmd->cmnd));
-       old_data_direction = scmd->sc_data_direction;
-       old_cmd_len = scmd->cmd_len;
-       old_use_sg = scmd->use_sg;
-
-       memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
-       memcpy(scmd->cmnd, cmnd, cmnd_size);
-
-       if (copy_sense) {
-               sg_init_one(&sgl, scmd->sense_buffer,
-                           sizeof(scmd->sense_buffer));
-
+       ses->cmd_len = scmd->cmd_len;
+       ses->cmnd = scmd->cmnd;
+       ses->data_direction = scmd->sc_data_direction;
+       ses->sdb = scmd->sdb;
+       ses->next_rq = scmd->request->next_rq;
+       ses->result = scmd->result;
+       ses->underflow = scmd->underflow;
+       ses->prot_op = scmd->prot_op;
+
+       scmd->prot_op = SCSI_PROT_NORMAL;
+       scmd->cmnd = ses->eh_cmnd;
+       memset(scmd->cmnd, 0, BLK_MAX_CDB);
+       memset(&scmd->sdb, 0, sizeof(scmd->sdb));
+       scmd->request->next_rq = NULL;
+
+       if (sense_bytes) {
+               scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE,
+                                        sense_bytes);
+               sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
+                           scmd->sdb.length);
+               scmd->sdb.table.sgl = &ses->sense_sgl;
                scmd->sc_data_direction = DMA_FROM_DEVICE;
-               scmd->request_bufflen = sgl.length;
-               scmd->request_buffer = &sgl;
-               scmd->use_sg = 1;
+               scmd->sdb.table.nents = 1;
+               scmd->cmnd[0] = REQUEST_SENSE;
+               scmd->cmnd[4] = scmd->sdb.length;
+               scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
        } else {
-               scmd->request_buffer = NULL;
-               scmd->request_bufflen = 0;
                scmd->sc_data_direction = DMA_NONE;
-               scmd->use_sg = 0;
+               if (cmnd) {
+                       BUG_ON(cmnd_size > BLK_MAX_CDB);
+                       memcpy(scmd->cmnd, cmnd, cmnd_size);
+                       scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
+               }
        }
 
        scmd->underflow = 0;
-       scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
 
-       if (sdev->scsi_level <= SCSI_2)
+       if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN)
                scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
                        (sdev->lun << 5 & 0xe0);
 
@@ -667,14 +734,64 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
         * Zero the sense buffer.  The scsi spec mandates that any
         * untransferred sense data should be interpreted as being zero.
         */
-       memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
+       memset(scmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
+}
+EXPORT_SYMBOL(scsi_eh_prep_cmnd);
+
+/**
+ * scsi_eh_restore_cmnd  - Restore a scsi command info as part of error recory
+ * @scmd:       SCSI command structure to restore
+ * @ses:        saved information from a coresponding call to scsi_eh_prep_cmnd
+ *
+ * Undo any damage done by above scsi_eh_prep_cmnd().
+ */
+void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
+{
+       /*
+        * Restore original data
+        */
+       scmd->cmd_len = ses->cmd_len;
+       scmd->cmnd = ses->cmnd;
+       scmd->sc_data_direction = ses->data_direction;
+       scmd->sdb = ses->sdb;
+       scmd->request->next_rq = ses->next_rq;
+       scmd->result = ses->result;
+       scmd->underflow = ses->underflow;
+       scmd->prot_op = ses->prot_op;
+}
+EXPORT_SYMBOL(scsi_eh_restore_cmnd);
 
+/**
+ * scsi_send_eh_cmnd  - submit a scsi command as part of error recory
+ * @scmd:       SCSI command structure to hijack
+ * @cmnd:       CDB to send
+ * @cmnd_size:  size in bytes of @cmnd
+ * @timeout:    timeout for this request
+ * @sense_bytes: size of sense data to copy or 0
+ *
+ * This function is used to send a scsi command down to a target device
+ * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
+ *
+ * Return value:
+ *    SUCCESS or FAILED or NEEDS_RETRY
+ */
+static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
+                            int cmnd_size, int timeout, unsigned sense_bytes)
+{
+       struct scsi_device *sdev = scmd->device;
+       struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
+       struct Scsi_Host *shost = sdev->host;
+       DECLARE_COMPLETION_ONSTACK(done);
+       unsigned long timeleft;
+       struct scsi_eh_save ses;
+       int rtn;
+
+       scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
        shost->eh_action = &done;
 
-       spin_lock_irqsave(shost->host_lock, flags);
        scsi_log_send(scmd);
-       shost->hostt->queuecommand(scmd, scsi_eh_done);
-       spin_unlock_irqrestore(shost->host_lock, flags);
+       scmd->scsi_done = scsi_eh_done;
+       shost->hostt->queuecommand(shost, scmd);
 
        timeleft = wait_for_completion_timeout(&done, timeout);
 
@@ -684,7 +801,7 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
 
        SCSI_LOG_ERROR_RECOVERY(3,
                printk("%s: scmd: %p, timeleft: %ld\n",
-                       __FUNCTION__, scmd, timeleft));
+                       __func__, scmd, timeleft));
 
        /*
         * If there is time left scsi_eh_done got called, and we will
@@ -696,12 +813,16 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
                rtn = scsi_eh_completed_normally(scmd);
                SCSI_LOG_ERROR_RECOVERY(3,
                        printk("%s: scsi_eh_completed_normally %x\n",
-                              __FUNCTION__, rtn));
+                              __func__, rtn));
 
                switch (rtn) {
                case SUCCESS:
                case NEEDS_RETRY:
                case FAILED:
+               case TARGET_ERROR:
+                       break;
+               case ADD_TO_MLQUEUE:
+                       rtn = NEEDS_RETRY;
                        break;
                default:
                        rtn = FAILED;
@@ -712,17 +833,11 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
                rtn = FAILED;
        }
 
+       scsi_eh_restore_cmnd(scmd, &ses);
+
+       if (sdrv->eh_action)
+               rtn = sdrv->eh_action(scmd, cmnd, cmnd_size, rtn);
 
-       /*
-        * Restore original data
-        */
-       scmd->request_buffer = old_buffer;
-       scmd->request_bufflen = old_bufflen;
-       memcpy(scmd->cmnd, old_cmnd, sizeof(scmd->cmnd));
-       scmd->sc_data_direction = old_data_direction;
-       scmd->cmd_len = old_cmd_len;
-       scmd->use_sg = old_use_sg;
-       scmd->result = old_result;
        return rtn;
 }
 
@@ -734,13 +849,10 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
  *    Some hosts automatically obtain this information, others require
  *    that we obtain it on our own. This function will *not* return until
  *    the command either times out, or it completes.
- **/
+ */
 static int scsi_request_sense(struct scsi_cmnd *scmd)
 {
-       static unsigned char generic_sense[6] =
-               {REQUEST_SENSE, 0, 0, 0, 252, 0};
-
-       return scsi_send_eh_cmnd(scmd, generic_sense, 6, SENSE_TIMEOUT, 1);
+       return scsi_send_eh_cmnd(scmd, NULL, 0, SENSE_TIMEOUT, ~0);
 }
 
 /**
@@ -751,10 +863,10 @@ static int scsi_request_sense(struct scsi_cmnd *scmd)
  * Notes:
  *    We don't want to use the normal command completion while we are are
  *    still handling errors - it may cause other commands to be queued,
- *    and that would disturb what we are doing.  thus we really want to
+ *    and that would disturb what we are doing.  Thus we really want to
  *    keep a list of pending commands for final completion, and once we
  *    are ready to leave error handling we handle completion for real.
- **/
+ */
 void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
 {
        scmd->device->host->host_failed--;
@@ -766,15 +878,15 @@ EXPORT_SYMBOL(scsi_eh_finish_cmd);
 /**
  * scsi_eh_get_sense - Get device sense data.
  * @work_q:    Queue of commands to process.
- * @done_q:    Queue of proccessed commands..
+ * @done_q:    Queue of processed commands.
  *
  * Description:
  *    See if we need to request sense information.  if so, then get it
- *    now, so we have a better idea of what to do.  
+ *    now, so we have a better idea of what to do.
  *
  * Notes:
  *    This has the unfortunate side effect that if a shost adapter does
- *    not automatically request sense information, that we end up shutting
+ *    not automatically request sense information, we end up shutting
  *    it down before we request it.
  *
  *    All drivers should request sense information internally these days,
@@ -782,7 +894,7 @@ EXPORT_SYMBOL(scsi_eh_finish_cmd);
  *
  *    XXX: Long term this code should go away, but that needs an audit of
  *         all LLDDs first.
- **/
+ */
 int scsi_eh_get_sense(struct list_head *work_q,
                      struct list_head *done_q)
 {
@@ -830,11 +942,11 @@ EXPORT_SYMBOL_GPL(scsi_eh_get_sense);
 
 /**
  * scsi_eh_tur - Send TUR to device.
- * @scmd:      Scsi cmd to send TUR
+ * @scmd:      &scsi_cmnd to send TUR
  *
  * Return value:
  *    0 - Device is ready. 1 - Device NOT ready.
- **/
+ */
 static int scsi_eh_tur(struct scsi_cmnd *scmd)
 {
        static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
@@ -844,7 +956,7 @@ retry_tur:
        rtn = scsi_send_eh_cmnd(scmd, tur_command, 6, SENSE_TIMEOUT, 0);
 
        SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
-               __FUNCTION__, scmd, rtn));
+               __func__, scmd, rtn));
 
        switch (rtn) {
        case NEEDS_RETRY:
@@ -859,21 +971,64 @@ retry_tur:
 }
 
 /**
- * scsi_eh_abort_cmds - abort canceled commands.
- * @shost:     scsi host being recovered.
- * @eh_done_q: list_head for processed commands.
+ * scsi_eh_test_devices - check if devices are responding from error recovery.
+ * @cmd_list:  scsi commands in error recovery.
+ * @work_q:     queue for commands which still need more error recovery
+ * @done_q:     queue for commands which are finished
+ * @try_stu:    boolean on if a STU command should be tried in addition to TUR.
+ *
+ * Decription:
+ *    Tests if devices are in a working state.  Commands to devices now in
+ *    a working state are sent to the done_q while commands to devices which
+ *    are still failing to respond are returned to the work_q for more
+ *    processing.
+ **/
+static int scsi_eh_test_devices(struct list_head *cmd_list,
+                               struct list_head *work_q,
+                               struct list_head *done_q, int try_stu)
+{
+       struct scsi_cmnd *scmd, *next;
+       struct scsi_device *sdev;
+       int finish_cmds;
+
+       while (!list_empty(cmd_list)) {
+               scmd = list_entry(cmd_list->next, struct scsi_cmnd, eh_entry);
+               sdev = scmd->device;
+
+               finish_cmds = !scsi_device_online(scmd->device) ||
+                       (try_stu && !scsi_eh_try_stu(scmd) &&
+                        !scsi_eh_tur(scmd)) ||
+                       !scsi_eh_tur(scmd);
+
+               list_for_each_entry_safe(scmd, next, cmd_list, eh_entry)
+                       if (scmd->device == sdev) {
+                               if (finish_cmds)
+                                       scsi_eh_finish_cmd(scmd, done_q);
+                               else
+                                       list_move_tail(&scmd->eh_entry, work_q);
+                       }
+       }
+       return list_empty(work_q);
+}
+
+
+/**
+ * scsi_eh_abort_cmds - abort pending commands.
+ * @work_q:    &list_head for pending commands.
+ * @done_q:    &list_head for processed commands.
  *
  * Decription:
  *    Try and see whether or not it makes sense to try and abort the
- *    running command.  this only works out to be the case if we have one
- *    command that has timed out.  if the command simply failed, it makes
+ *    running command.  This only works out to be the case if we have one
+ *    command that has timed out.  If the command simply failed, it makes
  *    no sense to try and abort the command, since as far as the shost
  *    adapter is concerned, it isn't running.
- **/
+ */
 static int scsi_eh_abort_cmds(struct list_head *work_q,
                              struct list_head *done_q)
 {
        struct scsi_cmnd *scmd, *next;
+       LIST_HEAD(check_list);
        int rtn;
 
        list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
@@ -882,14 +1037,13 @@ static int scsi_eh_abort_cmds(struct list_head *work_q,
                SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:"
                                                  "0x%p\n", current->comm,
                                                  scmd));
-               rtn = scsi_try_to_abort_cmd(scmd);
-               if (rtn == SUCCESS) {
+               rtn = scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd);
+               if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
                        scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD;
-                       if (!scsi_device_online(scmd->device) ||
-                           !scsi_eh_tur(scmd)) {
+                       if (rtn == FAST_IO_FAIL)
                                scsi_eh_finish_cmd(scmd, done_q);
-                       }
-                               
+                       else
+                               list_move_tail(&scmd->eh_entry, &check_list);
                } else
                        SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting"
                                                          " cmd failed:"
@@ -898,16 +1052,16 @@ static int scsi_eh_abort_cmds(struct list_head *work_q,
                                                          scmd));
        }
 
-       return list_empty(work_q);
+       return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
 }
 
 /**
  * scsi_eh_try_stu - Send START_UNIT to device.
- * @scmd:      Scsi cmd to send START_UNIT
+ * @scmd:      &scsi_cmnd to send START_UNIT
  *
  * Return value:
  *    0 - Device is ready. 1 - Device NOT ready.
- **/
+ */
 static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
 {
        static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
@@ -916,8 +1070,7 @@ static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
                int i, rtn = NEEDS_RETRY;
 
                for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)
-                       rtn = scsi_send_eh_cmnd(scmd, stu_command, 6,
-                                               scmd->device->timeout, 0);
+                       rtn = scsi_send_eh_cmnd(scmd, stu_command, 6, scmd->device->request_queue->rq_timeout, 0);
 
                if (rtn == SUCCESS)
                        return 0;
@@ -928,13 +1081,14 @@ static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
 
  /**
  * scsi_eh_stu - send START_UNIT if needed
- * @shost:     scsi host being recovered.
- * @eh_done_q: list_head for processed commands.
+ * @shost:     &scsi host being recovered.
+ * @work_q:     &list_head for pending commands.
+ * @done_q:    &list_head for processed commands.
  *
  * Notes:
  *    If commands are failing due to not ready, initializing command required,
- *     try revalidating the device, which will end up sending a start unit. 
- **/
+ *     try revalidating the device, which will end up sending a start unit.
+ */
 static int scsi_eh_stu(struct Scsi_Host *shost,
                              struct list_head *work_q,
                              struct list_head *done_q)
@@ -980,14 +1134,15 @@ static int scsi_eh_stu(struct Scsi_Host *shost,
 /**
  * scsi_eh_bus_device_reset - send bdr if needed
  * @shost:     scsi host being recovered.
- * @eh_done_q: list_head for processed commands.
+ * @work_q:     &list_head for pending commands.
+ * @done_q:    &list_head for processed commands.
  *
  * Notes:
- *    Try a bus device reset.  still, look to see whether we have multiple
+ *    Try a bus device reset.  Still, look to see whether we have multiple
  *    devices that are jammed or not - if we have multiple devices, it
  *    makes no sense to try bus_device_reset - we really would need to try
- *    a bus_reset instead. 
- **/
+ *    a bus_reset instead.
+ */
 static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
                                    struct list_head *work_q,
                                    struct list_head *done_q)
@@ -1011,8 +1166,9 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
                                                  " 0x%p\n", current->comm,
                                                  sdev));
                rtn = scsi_try_bus_device_reset(bdr_scmd);
-               if (rtn == SUCCESS) {
+               if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
                        if (!scsi_device_online(sdev) ||
+                           rtn == FAST_IO_FAIL ||
                            !scsi_eh_tur(bdr_scmd)) {
                                list_for_each_entry_safe(scmd, next,
                                                         work_q, eh_entry) {
@@ -1034,15 +1190,69 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
 }
 
 /**
- * scsi_eh_bus_reset - send a bus reset 
+ * scsi_eh_target_reset - send target reset if needed
  * @shost:     scsi host being recovered.
- * @eh_done_q: list_head for processed commands.
- **/
+ * @work_q:     &list_head for pending commands.
+ * @done_q:    &list_head for processed commands.
+ *
+ * Notes:
+ *    Try a target reset.
+ */
+static int scsi_eh_target_reset(struct Scsi_Host *shost,
+                               struct list_head *work_q,
+                               struct list_head *done_q)
+{
+       LIST_HEAD(tmp_list);
+       LIST_HEAD(check_list);
+
+       list_splice_init(work_q, &tmp_list);
+
+       while (!list_empty(&tmp_list)) {
+               struct scsi_cmnd *next, *scmd;
+               int rtn;
+               unsigned int id;
+
+               scmd = list_entry(tmp_list.next, struct scsi_cmnd, eh_entry);
+               id = scmd_id(scmd);
+
+               SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending target reset "
+                                                 "to target %d\n",
+                                                 current->comm, id));
+               rtn = scsi_try_target_reset(scmd);
+               if (rtn != SUCCESS && rtn != FAST_IO_FAIL)
+                       SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Target reset"
+                                                         " failed target: "
+                                                         "%d\n",
+                                                         current->comm, id));
+               list_for_each_entry_safe(scmd, next, &tmp_list, eh_entry) {
+                       if (scmd_id(scmd) != id)
+                               continue;
+
+                       if (rtn == SUCCESS)
+                               list_move_tail(&scmd->eh_entry, &check_list);
+                       else if (rtn == FAST_IO_FAIL)
+                               scsi_eh_finish_cmd(scmd, done_q);
+                       else
+                               /* push back on work queue for further processing */
+                               list_move(&scmd->eh_entry, work_q);
+               }
+       }
+
+       return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
+}
+
+/**
+ * scsi_eh_bus_reset - send a bus reset
+ * @shost:     &scsi host being recovered.
+ * @work_q:     &list_head for pending commands.
+ * @done_q:    &list_head for processed commands.
+ */
 static int scsi_eh_bus_reset(struct Scsi_Host *shost,
                             struct list_head *work_q,
                             struct list_head *done_q)
 {
        struct scsi_cmnd *scmd, *chan_scmd, *next;
+       LIST_HEAD(check_list);
        unsigned int channel;
        int rtn;
 
@@ -1050,7 +1260,7 @@ static int scsi_eh_bus_reset(struct Scsi_Host *shost,
         * we really want to loop over the various channels, and do this on
         * a channel by channel basis.  we should also check to see if any
         * of the failed commands are on soft_reset devices, and if so, skip
-        * the reset.  
+        * the reset.
         */
 
        for (channel = 0; channel <= shost->max_channel; channel++) {
@@ -1072,13 +1282,16 @@ static int scsi_eh_bus_reset(struct Scsi_Host *shost,
                                                  " %d\n", current->comm,
                                                  channel));
                rtn = scsi_try_bus_reset(chan_scmd);
-               if (rtn == SUCCESS) {
+               if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
                        list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
-                               if (channel == scmd_channel(scmd))
-                                       if (!scsi_device_online(scmd->device) ||
-                                           !scsi_eh_tur(scmd))
+                               if (channel == scmd_channel(scmd)) {
+                                       if (rtn == FAST_IO_FAIL)
                                                scsi_eh_finish_cmd(scmd,
                                                                   done_q);
+                                       else
+                                               list_move_tail(&scmd->eh_entry,
+                                                              &check_list);
+                               }
                        }
                } else {
                        SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST"
@@ -1087,18 +1300,19 @@ static int scsi_eh_bus_reset(struct Scsi_Host *shost,
                                                          channel));
                }
        }
-       return list_empty(work_q);
+       return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
 }
 
 /**
- * scsi_eh_host_reset - send a host reset 
+ * scsi_eh_host_reset - send a host reset
  * @work_q:    list_head for processed commands.
  * @done_q:    list_head for processed commands.
- **/
+ */
 static int scsi_eh_host_reset(struct list_head *work_q,
                              struct list_head *done_q)
 {
        struct scsi_cmnd *scmd, *next;
+       LIST_HEAD(check_list);
        int rtn;
 
        if (!list_empty(work_q)) {
@@ -1110,10 +1324,9 @@ static int scsi_eh_host_reset(struct list_head *work_q,
 
                rtn = scsi_try_host_reset(scmd);
                if (rtn == SUCCESS) {
+                       list_splice_init(work_q, &check_list);
+               } else if (rtn == FAST_IO_FAIL) {
                        list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
-                               if (!scsi_device_online(scmd->device) ||
-                                   (!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) ||
-                                   !scsi_eh_tur(scmd))
                                        scsi_eh_finish_cmd(scmd, done_q);
                        }
                } else {
@@ -1122,15 +1335,14 @@ static int scsi_eh_host_reset(struct list_head *work_q,
                                                          current->comm));
                }
        }
-       return list_empty(work_q);
+       return scsi_eh_test_devices(&check_list, work_q, done_q, 1);
 }
 
 /**
  * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
  * @work_q:    list_head for processed commands.
  * @done_q:    list_head for processed commands.
- *
- **/
+ */
 static void scsi_eh_offline_sdevs(struct list_head *work_q,
                                  struct list_head *done_q)
 {
@@ -1150,6 +1362,42 @@ static void scsi_eh_offline_sdevs(struct list_head *work_q,
        return;
 }
 
+/**
+ * scsi_noretry_cmd - determinte if command should be failed fast
+ * @scmd:      SCSI cmd to examine.
+ */
+int scsi_noretry_cmd(struct scsi_cmnd *scmd)
+{
+       switch (host_byte(scmd->result)) {
+       case DID_OK:
+               break;
+       case DID_BUS_BUSY:
+               return (scmd->request->cmd_flags & REQ_FAILFAST_TRANSPORT);
+       case DID_PARITY:
+               return (scmd->request->cmd_flags & REQ_FAILFAST_DEV);
+       case DID_ERROR:
+               if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
+                   status_byte(scmd->result) == RESERVATION_CONFLICT)
+                       return 0;
+               /* fall through */
+       case DID_SOFT_ERROR:
+               return (scmd->request->cmd_flags & REQ_FAILFAST_DRIVER);
+       }
+
+       switch (status_byte(scmd->result)) {
+       case CHECK_CONDITION:
+               /*
+                * assume caller has checked sense and determinted
+                * the check condition was retryable.
+                */
+               if (scmd->request->cmd_flags & REQ_FAILFAST_DEV ||
+                   scmd->request->cmd_type == REQ_TYPE_BLOCK_PC)
+                       return 1;
+       }
+
+       return 0;
+}
+
 /**
  * scsi_decide_disposition - Disposition a cmd on return from LLD.
  * @scmd:      SCSI cmd to examine.
@@ -1163,7 +1411,7 @@ static void scsi_eh_offline_sdevs(struct list_head *work_q,
  *    is woken.  In cases where the error code indicates an error that
  *    doesn't require the error handler read (i.e. we don't need to
  *    abort/reset), this function should return SUCCESS.
- **/
+ */
 int scsi_decide_disposition(struct scsi_cmnd *scmd)
 {
        int rtn;
@@ -1175,7 +1423,7 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
        if (!scsi_device_online(scmd->device)) {
                SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
                                                  " as SUCCESS\n",
-                                                 __FUNCTION__));
+                                                 __func__));
                return SUCCESS;
        }
 
@@ -1208,7 +1456,7 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
                return SUCCESS;
                /*
                 * when the low level driver returns did_soft_error,
-                * it is responsible for keeping an internal retry counter 
+                * it is responsible for keeping an internal retry counter
                 * in order to avoid endless loops (db)
                 *
                 * actually this is a bug in this function here.  we should
@@ -1222,7 +1470,21 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
 
        case DID_REQUEUE:
                return ADD_TO_MLQUEUE;
-
+       case DID_TRANSPORT_DISRUPTED:
+               /*
+                * LLD/transport was disrupted during processing of the IO.
+                * The transport class is now blocked/blocking,
+                * and the transport will decide what to do with the IO
+                * based on its timers and recovery capablilities if
+                * there are enough retries.
+                */
+               goto maybe_retry;
+       case DID_TRANSPORT_FAILFAST:
+               /*
+                * The transport decided to failfast the IO (most likely
+                * the fast io fail tmo fired), so send IO directly upwards.
+                */
+               return SUCCESS;
        case DID_ERROR:
                if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
                    status_byte(scmd->result) == RESERVATION_CONFLICT)
@@ -1232,7 +1494,6 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
                         */
                        break;
                /* fallthrough */
-
        case DID_BUS_BUSY:
        case DID_PARITY:
                goto maybe_retry;
@@ -1265,6 +1526,7 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
         */
        switch (status_byte(scmd->result)) {
        case QUEUE_FULL:
+               scsi_handle_queue_full(scmd->device);
                /*
                 * the case of trying to send too many commands to a
                 * tagged queueing device.
@@ -1278,13 +1540,23 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
                 */
                return ADD_TO_MLQUEUE;
        case GOOD:
+               scsi_handle_queue_ramp_up(scmd->device);
        case COMMAND_TERMINATED:
-       case TASK_ABORTED:
                return SUCCESS;
+       case TASK_ABORTED:
+               goto maybe_retry;
        case CHECK_CONDITION:
                rtn = scsi_check_sense(scmd);
                if (rtn == NEEDS_RETRY)
                        goto maybe_retry;
+               else if (rtn == TARGET_ERROR) {
+                       /*
+                        * Need to modify host byte to signal a
+                        * permanent target failure
+                        */
+                       set_host_byte(scmd, DID_TARGET_FAILURE);
+                       rtn = SUCCESS;
+               }
                /* if rtn == FAILED, we have no sense information;
                 * returning FAILED will wake the error handler thread
                 * to collect the sense and redo the decide
@@ -1302,6 +1574,7 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
        case RESERVATION_CONFLICT:
                sdev_printk(KERN_INFO, scmd->device,
                            "reservation conflict\n");
+               set_host_byte(scmd, DID_NEXUS_FAILURE);
                return SUCCESS; /* causes immediate i/o error */
        default:
                return FAILED;
@@ -1315,7 +1588,7 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
         * even if the request is marked fast fail, we still requeue
         * for queue congestion conditions (QUEUE_FULL or BUSY) */
        if ((++scmd->retries) <= scmd->allowed
-           && !blk_noretry_request(scmd->request)) {
+           && !scsi_noretry_cmd(scmd)) {
                return NEEDS_RETRY;
        } else {
                /*
@@ -1325,41 +1598,48 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
        }
 }
 
+static void eh_lock_door_done(struct request *req, int uptodate)
+{
+       __blk_put_request(req->q, req);
+}
+
 /**
  * scsi_eh_lock_door - Prevent medium removal for the specified device
  * @sdev:      SCSI device to prevent medium removal
  *
  * Locking:
- *     We must be called from process context; scsi_allocate_request()
- *     may sleep.
+ *     We must be called from process context.
  *
  * Notes:
  *     We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
  *     head of the devices request queue, and continue.
- *
- * Bugs:
- *     scsi_allocate_request() may sleep waiting for existing requests to
- *     be processed.  However, since we haven't kicked off any request
- *     processing for this host, this may deadlock.
- *
- *     If scsi_allocate_request() fails for what ever reason, we
- *     completely forget to lock the door.
- **/
+ */
 static void scsi_eh_lock_door(struct scsi_device *sdev)
 {
-       unsigned char cmnd[MAX_COMMAND_SIZE];
+       struct request *req;
 
-       cmnd[0] = ALLOW_MEDIUM_REMOVAL;
-       cmnd[1] = 0;
-       cmnd[2] = 0;
-       cmnd[3] = 0;
-       cmnd[4] = SCSI_REMOVAL_PREVENT;
-       cmnd[5] = 0;
+       /*
+        * blk_get_request with GFP_KERNEL (__GFP_WAIT) sleeps until a
+        * request becomes available
+        */
+       req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL);
 
-       scsi_execute_async(sdev, cmnd, 6, DMA_NONE, NULL, 0, 0, 10 * HZ,
-                          5, NULL, NULL, GFP_KERNEL);
-}
+       req->cmd[0] = ALLOW_MEDIUM_REMOVAL;
+       req->cmd[1] = 0;
+       req->cmd[2] = 0;
+       req->cmd[3] = 0;
+       req->cmd[4] = SCSI_REMOVAL_PREVENT;
+       req->cmd[5] = 0;
+
+       req->cmd_len = COMMAND_SIZE(req->cmd[0]);
 
+       req->cmd_type = REQ_TYPE_BLOCK_PC;
+       req->cmd_flags |= REQ_QUIET;
+       req->timeout = 10 * HZ;
+       req->retries = 5;
+
+       blk_execute_rq_nowait(req->q, NULL, req, 1, eh_lock_door_done);
+}
 
 /**
  * scsi_restart_operations - restart io operations to the specified host.
@@ -1368,7 +1648,7 @@ static void scsi_eh_lock_door(struct scsi_device *sdev)
  * Notes:
  *    When we entered the error handler, we blocked all further i/o to
  *    this device.  we need to 'reverse' this process.
- **/
+ */
 static void scsi_restart_operations(struct Scsi_Host *shost)
 {
        struct scsi_device *sdev;
@@ -1390,7 +1670,7 @@ static void scsi_restart_operations(struct Scsi_Host *shost)
         * ioctls to queued block devices.
         */
        SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
-                                         __FUNCTION__));
+                                         __func__));
 
        spin_lock_irqsave(shost->host_lock, flags);
        if (scsi_host_set_state(shost, SHOST_RUNNING))
@@ -1412,26 +1692,27 @@ static void scsi_restart_operations(struct Scsi_Host *shost)
 /**
  * scsi_eh_ready_devs - check device ready state and recover if not.
  * @shost:     host to be recovered.
- * @eh_done_q: list_head for processed commands.
- *
- **/
+ * @work_q:     &list_head for pending commands.
+ * @done_q:    &list_head for processed commands.
+ */
 void scsi_eh_ready_devs(struct Scsi_Host *shost,
                        struct list_head *work_q,
                        struct list_head *done_q)
 {
        if (!scsi_eh_stu(shost, work_q, done_q))
                if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
-                       if (!scsi_eh_bus_reset(shost, work_q, done_q))
-                               if (!scsi_eh_host_reset(work_q, done_q))
-                                       scsi_eh_offline_sdevs(work_q, done_q);
+                       if (!scsi_eh_target_reset(shost, work_q, done_q))
+                               if (!scsi_eh_bus_reset(shost, work_q, done_q))
+                                       if (!scsi_eh_host_reset(work_q, done_q))
+                                               scsi_eh_offline_sdevs(work_q,
+                                                                     done_q);
 }
 EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
 
 /**
  * scsi_eh_flush_done_q - finish processed commands or retry them.
  * @done_q:    list_head of processed commands.
- *
- **/
+ */
 void scsi_eh_flush_done_q(struct list_head *done_q)
 {
        struct scsi_cmnd *scmd, *next;
@@ -1439,7 +1720,7 @@ void scsi_eh_flush_done_q(struct list_head *done_q)
        list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
                list_del_init(&scmd->eh_entry);
                if (scsi_device_online(scmd->device) &&
-                   !blk_noretry_request(scmd->request) &&
+                   !scsi_noretry_cmd(scmd) &&
                    (++scmd->retries <= scmd->allowed)) {
                        SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
                                                          " retry cmd: %p\n",
@@ -1485,7 +1766,7 @@ EXPORT_SYMBOL(scsi_eh_flush_done_q);
  *    scsi_finish_cmd() called for it.  we do all of the retry stuff
  *    here, so when we restart the host after we return it should have an
  *    empty queue.
- **/
+ */
 static void scsi_unjam_host(struct Scsi_Host *shost)
 {
        unsigned long flags;
@@ -1512,7 +1793,7 @@ static void scsi_unjam_host(struct Scsi_Host *shost)
  * Notes:
  *    This is the main error handling loop.  This is run as a kernel thread
  *    for every SCSI host and handles all error handling activity.
- **/
+ */
 int scsi_error_handler(void *data)
 {
        struct Scsi_Host *shost = data;
@@ -1521,7 +1802,7 @@ int scsi_error_handler(void *data)
         * We use TASK_INTERRUPTIBLE so that the thread is not
         * counted against the load average as a running process.
         * We never actually get interrupted because kthread_run
-        * disables singal delivery for the created thread.
+        * disables signal delivery for the created thread.
         */
        set_current_state(TASK_INTERRUPTIBLE);
        while (!kthread_should_stop()) {
@@ -1545,6 +1826,14 @@ int scsi_error_handler(void *data)
                 * what we need to do to get it up and online again (if we can).
                 * If we fail, we end up taking the thing offline.
                 */
+               if (!shost->eh_noresume && scsi_autopm_get_host(shost) != 0) {
+                       SCSI_LOG_ERROR_RECOVERY(1,
+                               printk(KERN_ERR "Error handler scsi_eh_%d "
+                                               "unable to autoresume\n",
+                                               shost->host_no));
+                       continue;
+               }
+
                if (shost->transportt->eh_strategy_handler)
                        shost->transportt->eh_strategy_handler(shost);
                else
@@ -1558,6 +1847,8 @@ int scsi_error_handler(void *data)
                 * which are still online.
                 */
                scsi_restart_operations(shost);
+               if (!shost->eh_noresume)
+                       scsi_autopm_put_host(shost);
                set_current_state(TASK_INTERRUPTIBLE);
        }
        __set_current_state(TASK_RUNNING);
@@ -1594,10 +1885,8 @@ void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
        struct scsi_device *sdev;
 
        __shost_for_each_device(sdev, shost) {
-               if (channel == sdev_channel(sdev)) {
-                       sdev->was_reset = 1;
-                       sdev->expecting_cc_ua = 1;
-               }
+               if (channel == sdev_channel(sdev))
+                       __scsi_report_device_reset(sdev, NULL);
        }
 }
 EXPORT_SYMBOL(scsi_report_bus_reset);
@@ -1630,10 +1919,8 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
 
        __shost_for_each_device(sdev, shost) {
                if (channel == sdev_channel(sdev) &&
-                   target == sdev_id(sdev)) {
-                       sdev->was_reset = 1;
-                       sdev->expecting_cc_ua = 1;
-               }
+                   target == sdev_id(sdev))
+                       __scsi_report_device_reset(sdev, NULL);
        }
 }
 EXPORT_SYMBOL(scsi_report_device_reset);
@@ -1659,27 +1946,28 @@ scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
 int
 scsi_reset_provider(struct scsi_device *dev, int flag)
 {
-       struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL);
+       struct scsi_cmnd *scmd;
        struct Scsi_Host *shost = dev->host;
        struct request req;
        unsigned long flags;
        int rtn;
 
+       if (scsi_autopm_get_host(shost) < 0)
+               return FAILED;
+
+       scmd = scsi_get_command(dev, GFP_KERNEL);
+       blk_rq_init(NULL, &req);
        scmd->request = &req;
-       memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
 
-       memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd));
-    
+       scmd->cmnd = req.cmd;
+
        scmd->scsi_done         = scsi_reset_provider_done_command;
-       scmd->request_buffer            = NULL;
-       scmd->request_bufflen           = 0;
+       memset(&scmd->sdb, 0, sizeof(scmd->sdb));
 
        scmd->cmd_len                   = 0;
 
        scmd->sc_data_direction         = DMA_BIDIRECTIONAL;
 
-       init_timer(&scmd->eh_timeout);
-
        spin_lock_irqsave(shost->host_lock, flags);
        shost->tmf_in_progress = 1;
        spin_unlock_irqrestore(shost->host_lock, flags);
@@ -1690,6 +1978,11 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
                if (rtn == SUCCESS)
                        break;
                /* FALLTHROUGH */
+       case SCSI_TRY_RESET_TARGET:
+               rtn = scsi_try_target_reset(scmd);
+               if (rtn == SUCCESS)
+                       break;
+               /* FALLTHROUGH */
        case SCSI_TRY_RESET_BUS:
                rtn = scsi_try_bus_reset(scmd);
                if (rtn == SUCCESS)
@@ -1712,13 +2005,14 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
         */
        SCSI_LOG_ERROR_RECOVERY(3,
                printk("%s: waking up host to restart after TMF\n",
-               __FUNCTION__));
+               __func__));
 
        wake_up(&shost->host_wait);
 
        scsi_run_host_queues(shost);
 
        scsi_next_command(scmd);
+       scsi_autopm_put_host(shost);
        return rtn;
 }
 EXPORT_SYMBOL(scsi_reset_provider);
@@ -1741,7 +2035,7 @@ EXPORT_SYMBOL(scsi_reset_provider);
  *
  * Return value:
  *     1 if valid sense data information found, else 0;
- **/
+ */
 int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
                          struct scsi_sense_hdr *sshdr)
 {
@@ -1768,7 +2062,7 @@ int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
                if (sb_len > 7)
                        sshdr->additional_length = sense_buffer[7];
        } else {
-               /* 
+               /*
                 * fixed format
                 */
                if (sb_len > 2)
@@ -1791,14 +2085,12 @@ int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
                                 struct scsi_sense_hdr *sshdr)
 {
        return scsi_normalize_sense(cmd->sense_buffer,
-                       sizeof(cmd->sense_buffer), sshdr);
+                       SCSI_SENSE_BUFFERSIZE, sshdr);
 }
 EXPORT_SYMBOL(scsi_command_normalize_sense);
 
 /**
- * scsi_sense_desc_find - search for a given descriptor type in
- *                     descriptor sense data format.
- *
+ * scsi_sense_desc_find - search for a given descriptor type in        descriptor sense data format.
  * @sense_buffer:      byte array of descriptor format sense data
  * @sb_len:            number of valid bytes in sense_buffer
  * @desc_type:         value of descriptor type to find
@@ -1809,7 +2101,7 @@ EXPORT_SYMBOL(scsi_command_normalize_sense);
  *
  * Return value:
  *     pointer to start of (first) descriptor if found else NULL
- **/
+ */
 const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
                                int desc_type)
 {
@@ -1837,9 +2129,7 @@ const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
 EXPORT_SYMBOL(scsi_sense_desc_find);
 
 /**
- * scsi_get_sense_info_fld - attempts to get information field from
- *                     sense data (either fixed or descriptor format)
- *
+ * scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
  * @sense_buffer:      byte array of sense data
  * @sb_len:            number of valid bytes in sense_buffer
  * @info_out:          pointer to 64 integer where 8 or 4 byte information
@@ -1847,7 +2137,7 @@ EXPORT_SYMBOL(scsi_sense_desc_find);
  *
  * Return value:
  *     1 if information field found, 0 if not found.
- **/
+ */
 int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
                            u64 * info_out)
 {
@@ -1887,3 +2177,31 @@ int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
        }
 }
 EXPORT_SYMBOL(scsi_get_sense_info_fld);
+
+/**
+ * scsi_build_sense_buffer - build sense data in a buffer
+ * @desc:      Sense format (non zero == descriptor format,
+ *             0 == fixed format)
+ * @buf:       Where to build sense data
+ * @key:       Sense key
+ * @asc:       Additional sense code
+ * @ascq:      Additional sense code qualifier
+ *
+ **/
+void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
+{
+       if (desc) {
+               buf[0] = 0x72;  /* descriptor, current */
+               buf[1] = key;
+               buf[2] = asc;
+               buf[3] = ascq;
+               buf[7] = 0;
+       } else {
+               buf[0] = 0x70;  /* fixed, current */
+               buf[2] = key;
+               buf[7] = 0xa;
+               buf[12] = asc;
+               buf[13] = ascq;
+       }
+}
+EXPORT_SYMBOL(scsi_build_sense_buffer);