[09/14] scsi: mpt3sas: Remove in_interrupt().

Commit Message

Sebastian Andrzej Siewior Nov. 26, 2020, 1:29 p.m. UTC

From: "Ahmed S. Darwish" <[e-mail]>

_scsih_fw_event_cleanup_queue() waits for all outstanding firmware
events wokrqueue handlers to finish. If in_interrupt() is true, it
cancels itself and return early.

That in_interrupt() check is ill-defined and does not provide what the
name suggests: it does not cover all states in which it is safe to block
and call functions like cancel_work_sync().

That check is also not needed: _scsih_fw_event_cleanup_queue() is always
invoked from process context. Below is an analysis of its callers:

  - scsih_remove(), bound to PCI ->remove(), process context

  - scsih_shutdown(), bound to PCI ->shutdown(), process context

  - mpt3sas_scsih_clear_outstanding_scsi_tm_commands(), called by
      => _base_clear_outstanding_commands(), called by
        =>_base_fault_reset_work(), workqueue
        => mpt3sas_base_hard_reset_handler(), locks mutex

Remove the in_interrupt() check. Change _scsih_fw_event_cleanup_queue()
specification to a purely process-context function and mark it with
"Context: task, can sleep".

Signed-off-by: Ahmed S. Darwish <[e-mail]>
Signed-off-by: Sebastian Andrzej Siewior <[e-mail]>
Cc: Sathya Prakash <[e-mail]>
Cc: Sreekanth Reddy <[e-mail]>
Cc: Suganath Prabu Subramani <[e-mail]>
Cc: <[e-mail]>
---
 drivers/scsi/mpt3sas/mpt3sas_scsih.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Daniel Wagner Nov. 30, 2020, 3:16 p.m. UTC | #1

On Thu, Nov 26, 2020 at 02:29:47PM +0100, Sebastian Andrzej Siewior wrote:
> From: "Ahmed S. Darwish" <[e-mail]>
> 
> _scsih_fw_event_cleanup_queue() waits for all outstanding firmware
> events wokrqueue handlers to finish. If in_interrupt() is true, it
> cancels itself and return early.
> 
> That in_interrupt() check is ill-defined and does not provide what the
> name suggests: it does not cover all states in which it is safe to block
> and call functions like cancel_work_sync().
> 
> That check is also not needed: _scsih_fw_event_cleanup_queue() is always
> invoked from process context. Below is an analysis of its callers:
> 
>   - scsih_remove(), bound to PCI ->remove(), process context
> 
>   - scsih_shutdown(), bound to PCI ->shutdown(), process context
> 
>   - mpt3sas_scsih_clear_outstanding_scsi_tm_commands(), called by
>       => _base_clear_outstanding_commands(), called by
>         =>_base_fault_reset_work(), workqueue
>         => mpt3sas_base_hard_reset_handler(), locks mutex
> 
> Remove the in_interrupt() check. Change _scsih_fw_event_cleanup_queue()
> specification to a purely process-context function and mark it with
> "Context: task, can sleep".
> 
> Signed-off-by: Ahmed S. Darwish <[e-mail]>
> Signed-off-by: Sebastian Andrzej Siewior <[e-mail]>
> Cc: Sathya Prakash <[e-mail]>
> Cc: Sreekanth Reddy <[e-mail]>
> Cc: Suganath Prabu Subramani <[e-mail]>
> Cc: <[e-mail]>

Reviewed-by: Daniel Wagner <[e-mail]>

Patch

diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index f081adb85addc..d91f45abe6b86 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -3673,6 +3673,8 @@  static struct fw_event_work *dequeue_next_fw_event(struct MPT3SAS_ADAPTER *ioc)
  *
  * Walk the firmware event queue, either killing timers, or waiting
  * for outstanding events to complete
+ *
+ * Context: task, can sleep
  */
 static void
 _scsih_fw_event_cleanup_queue(struct MPT3SAS_ADAPTER *ioc)
@@ -3680,7 +3682,7 @@  _scsih_fw_event_cleanup_queue(struct MPT3SAS_ADAPTER *ioc)
 	struct fw_event_work *fw_event;
 
 	if ((list_empty(&ioc->fw_event_list) && !ioc->current_event) ||
-	     !ioc->firmware_event_thread || in_interrupt())
+	    !ioc->firmware_event_thread)
 		return;
 
 	ioc->fw_events_cleanup = 1;