[SCSI] improved eh timeout handler
When a command runs into a timeout we need to send an 'ABORT TASK'
TMF. This is typically done by the 'eh_abort_handler' LLDD callback.
Conceptually, however, this function is a normal SCSI command, so
there is no need to enter the error handler.
This patch implements a new scsi_abort_command() function which
invokes an asynchronous function scsi_eh_abort_handler() to
abort the commands via the usual 'eh_abort_handler'.
If abort succeeds the command is either retried or terminated,
depending on the number of allowed retries. However, 'eh_eflags'
records the abort, so if the retry would fail again the
command is pushed onto the error handler without trying to
abort it (again); it'll be cleared up from SCSI EH.
[hare: smatch detected stray switch fixed]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index fe3b58e..53075e5 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -479,6 +479,11 @@
unsigned no_write_same:1;
/*
+ * True if asynchronous aborts are not supported
+ */
+ unsigned no_async_abort:1;
+
+ /*
* Countdown for host blocking with no commands outstanding.
*/
unsigned int max_host_blocked;
@@ -690,6 +695,11 @@
struct workqueue_struct *work_q;
/*
+ * Task management function work queue
+ */
+ struct workqueue_struct *tmf_work_q;
+
+ /*
* Host has rejected a command because it was busy.
*/
unsigned int host_blocked;