1 files changed, 46 insertions, 111 deletions

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 0c5b02d4c7f8..18c5d2523014 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -417,43 +417,15 @@ static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
 }
 
 /**
- * scsi_eh_times_out - timeout function for error handling.
- * @scmd:       Cmd that is timing out.
- *
- * Notes:
- *    During error handling, the kernel thread will be sleeping waiting
- *    for some action to complete on the device.  our only job is to
- *    record that it timed out, and to wake up the thread.
- **/
-static void scsi_eh_times_out(struct scsi_cmnd *scmd)
-{
-        scmd->eh_eflags |= SCSI_EH_REC_TIMEOUT;
-        SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd:%p\n", __FUNCTION__,
-                                          scmd));
-
-        up(scmd->device->host->eh_action);
-}
-
-/**
  * scsi_eh_done - Completion function for error handling.
  * @scmd:       Cmd that is done.
  **/
 static void scsi_eh_done(struct scsi_cmnd *scmd)
 {
-        /*
-         * if the timeout handler is already running, then just set the
-         * flag which says we finished late, and return.  we have no
-         * way of stopping the timeout handler from running, so we must
-         * always defer to it.
-         */
-        if (del_timer(&scmd->eh_timeout)) {
-                scmd->request->rq_status = RQ_SCSI_DONE;
-
-                SCSI_LOG_ERROR_RECOVERY(3, printk("%s scmd: %p result: %x\n",
-                                           __FUNCTION__, scmd, scmd->result));
-
-                up(scmd->device->host->eh_action);
-        }
+        SCSI_LOG_ERROR_RECOVERY(3,
+                printk("%s scmd: %p result: %x\n",
+                        __FUNCTION__, scmd, scmd->result));
+        complete(scmd->device->host->eh_action);
 }
 
 /**
@@ -461,10 +433,6 @@ static void scsi_eh_done(struct scsi_cmnd *scmd)
  * @scmd:       SCSI Cmd to send.
  * @timeout:    Timeout for cmd.
  *
- * Notes:
- *    The initialization of the structures is quite a bit different in
- *    this case, and furthermore, there is a different completion handler
- *    vs scsi_dispatch_cmd.
  * Return value:
  *    SUCCESS or FAILED or NEEDS_RETRY
  **/
@@ -472,24 +440,16 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout)
 {
         struct scsi_device *sdev = scmd->device;
         struct Scsi_Host *shost = sdev->host;
-        DECLARE_MUTEX_LOCKED(sem);
+        DECLARE_COMPLETION(done);
+        unsigned long timeleft;
         unsigned long flags;
-        int rtn = SUCCESS;
+        int rtn;
 
-        /*
-         * we will use a queued command if possible, otherwise we will
-         * emulate the queuing and calling of completion function ourselves.
-         */
         if (sdev->scsi_level <= SCSI_2)
                 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
                         (sdev->lun << 5 & 0xe0);
 
-        scsi_add_timer(scmd, timeout, scsi_eh_times_out);
-
-        /*
-         * set up the semaphore so we wait for the command to complete.
-         */
-        shost->eh_action = &sem;
+        shost->eh_action = &done;
         scmd->request->rq_status = RQ_SCSI_BUSY;
 
         spin_lock_irqsave(shost->host_lock, flags);
@@ -497,47 +457,29 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout)
         shost->hostt->queuecommand(scmd, scsi_eh_done);
         spin_unlock_irqrestore(shost->host_lock, flags);
 
-        down(&sem);
-        scsi_log_completion(scmd, SUCCESS);
+        timeleft = wait_for_completion_timeout(&done, timeout);
 
+        scmd->request->rq_status = RQ_SCSI_DONE;
         shost->eh_action = NULL;
 
-        /*
-         * see if timeout.  if so, tell the host to forget about it.
-         * in other words, we don't want a callback any more.
-         */
-        if (scmd->eh_eflags & SCSI_EH_REC_TIMEOUT) {
-                scmd->eh_eflags &= ~SCSI_EH_REC_TIMEOUT;
-
-                /*
-                 * as far as the low level driver is
-                 * concerned, this command is still active, so
-                 * we must give the low level driver a chance
-                 * to abort it. (db) 
-                 *
-                 * FIXME(eric) - we are not tracking whether we could
-                 * abort a timed out command or not.  not sure how
-                 * we should treat them differently anyways.
-                 */
-                if (shost->hostt->eh_abort_handler)
-                        shost->hostt->eh_abort_handler(scmd);
-                        
-                scmd->request->rq_status = RQ_SCSI_DONE;
-                rtn = FAILED;
-        }
+        scsi_log_completion(scmd, SUCCESS);
 
-        SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd: %p, rtn:%x\n",
-                                          __FUNCTION__, scmd, rtn));
+        SCSI_LOG_ERROR_RECOVERY(3,
+                printk("%s: scmd: %p, timeleft: %ld\n",
+                        __FUNCTION__, scmd, timeleft));
 
         /*
-         * now examine the actual status codes to see whether the command
-         * actually did complete normally.
+         * If there is time left scsi_eh_done got called, and we will
+         * examine the actual status codes to see whether the command
+         * actually did complete normally, else tell the host to forget
+         * about this command.
          */
-        if (rtn == SUCCESS) {
+        if (timeleft) {
                 rtn = scsi_eh_completed_normally(scmd);
                 SCSI_LOG_ERROR_RECOVERY(3,
                         printk("%s: scsi_eh_completed_normally %x\n",
                                __FUNCTION__, rtn));
+
                 switch (rtn) {
                 case SUCCESS:
                 case NEEDS_RETRY:
@@ -547,6 +489,15 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout)
                         rtn = FAILED;
                         break;
                 }
+        } else {
+                /*
+                 * FIXME(eric) - we are not tracking whether we could
+                 * abort a timed out command or not.  not sure how
+                 * we should treat them differently anyways.
+                 */
+                if (shost->hostt->eh_abort_handler)
+                        shost->hostt->eh_abort_handler(scmd);
+                rtn = FAILED;
         }
 
         return rtn;
@@ -1571,50 +1522,41 @@ static void scsi_unjam_host(struct Scsi_Host *shost)
 }
 
 /**
- * scsi_error_handler - Handle errors/timeouts of SCSI cmds.
+ * scsi_error_handler - SCSI error handler thread
  * @data:       Host for which we are running.
  *
  * Notes:
- *    This is always run in the context of a kernel thread.  The idea is
- *    that we start this thing up when the kernel starts up (one per host
- *    that we detect), and it immediately goes to sleep and waits for some
- *    event (i.e. failure).  When this takes place, we have the job of
- *    trying to unjam the bus and restarting things.
+ *    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 = (struct Scsi_Host *) data;
-        int rtn;
+        struct Scsi_Host *shost = data;
 
         current->flags |= PF_NOFREEZE;
 
-        
         /*
-         * Note - we always use TASK_INTERRUPTIBLE even if the module
-         * was loaded as part of the kernel.  The reason is that
-         * UNINTERRUPTIBLE would cause this thread to be counted in
-         * the load average as a running process, and an interruptible
-         * wait doesn't.
+         * 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.
          */
         set_current_state(TASK_INTERRUPTIBLE);
         while (!kthread_should_stop()) {
                 if (shost->host_failed == 0 ||
                     shost->host_failed != shost->host_busy) {
-                        SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler"
-                                                          " scsi_eh_%d"
-                                                          " sleeping\n",
-                                                          shost->host_no));
+                        SCSI_LOG_ERROR_RECOVERY(1,
+                                printk("Error handler scsi_eh_%d sleeping\n",
+                                        shost->host_no));
                         schedule();
                         set_current_state(TASK_INTERRUPTIBLE);
                         continue;
                 }
 
                 __set_current_state(TASK_RUNNING);
-                SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler"
-                                                  " scsi_eh_%d waking"
-                                                  " up\n",shost->host_no));
-
-                shost->eh_active = 1;
+                SCSI_LOG_ERROR_RECOVERY(1,
+                        printk("Error handler scsi_eh_%d waking up\n",
+                                shost->host_no));
 
                 /*
                  * We have a host that is failing for some reason.  Figure out
@@ -1622,12 +1564,10 @@ int scsi_error_handler(void *data)
                  * If we fail, we end up taking the thing offline.
                  */
                 if (shost->hostt->eh_strategy_handler) 
-                        rtn = shost->hostt->eh_strategy_handler(shost);
+                        shost->hostt->eh_strategy_handler(shost);
                 else
                         scsi_unjam_host(shost);
 
-                shost->eh_active = 0;
-
                 /*
                  * Note - if the above fails completely, the action is to take
                  * individual devices offline and flush the queue of any
@@ -1638,15 +1578,10 @@ int scsi_error_handler(void *data)
                 scsi_restart_operations(shost);
                 set_current_state(TASK_INTERRUPTIBLE);
         }
-
         __set_current_state(TASK_RUNNING);
 
-        SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler scsi_eh_%d"
-                                          " exiting\n",shost->host_no));
-
-        /*
-         * Make sure that nobody tries to wake us up again.
-         */
+        SCSI_LOG_ERROR_RECOVERY(1,
+                printk("Error handler scsi_eh_%d exiting\n", shost->host_no));
         shost->ehandler = NULL;
         return 0;
 }