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path: root/drivers/scsi/scsi_error.c
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Diffstat (limited to 'drivers/scsi/scsi_error.c')
-rw-r--r--drivers/scsi/scsi_error.c157
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;
}