* [PATCH] Remove two cancel_delayed_work() calls from the mid-layer
@ 2014-06-02 9:50 Bart Van Assche
2014-06-02 9:51 ` Hannes Reinecke
2014-06-02 11:32 ` Christoph Hellwig
0 siblings, 2 replies; 3+ messages in thread
From: Bart Van Assche @ 2014-06-02 9:50 UTC (permalink / raw)
To: James Bottomley, Christoph Hellwig
Cc: Hannes Reinecke, Paolo Bonzini, Jens Axboe, Joe Lawrence,
linux-scsi@vger.kernel.org
scsi_put_command() is either invoked before blk_start_request() or
after block layer processing has completed. scsi_cmnd.abort_work
is scheduled from inside the SCSI timeout handler. The block layer
guarantees that either the regular completion handler
(softirq_done_fn()) or the timeout handler (rq_timed_out_fn()) is
invoked but not both. This means that scsi_put_command() is never
invoked while abort_work is scheduled. Hence remove the
cancel_delayed_work() call from scsi_put_command().
Similarly, scsi_abort_command() is only invoked from the SCSI
timeout handler. If scsi_abort_command() is invoked for a SCSI
command with the SCSI_EH_ABORT_SCHEDULED flag set this means that
scmd_eh_abort_handler() has already invoked scsi_queue_insert() and
hence that scsi_cmnd.abort_work is no longer pending. Hence also
remove the cancel_delayed_work() call from scsi_abort_command().
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Joe Lawrence <jdl1291@gmail.com>
---
drivers/scsi/scsi.c | 2 +-
drivers/scsi/scsi_error.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 88d46fe..53b8b94 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -334,7 +334,7 @@ void scsi_put_command(struct scsi_cmnd *cmd)
list_del_init(&cmd->list);
spin_unlock_irqrestore(&cmd->device->list_lock, flags);
- cancel_delayed_work(&cmd->abort_work);
+ BUG_ON(delayed_work_pending(&cmd->abort_work));
__scsi_put_command(cmd->device->host, cmd);
}
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index f17aa7a..919ade2 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -193,7 +193,7 @@ scsi_abort_command(struct scsi_cmnd *scmd)
SCSI_LOG_ERROR_RECOVERY(3,
scmd_printk(KERN_INFO, scmd,
"scmd %p previous abort failed\n", scmd));
- cancel_delayed_work(&scmd->abort_work);
+ BUG_ON(delayed_work_pending(&scmd->abort_work));
return FAILED;
}
--
1.8.4.5
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] Remove two cancel_delayed_work() calls from the mid-layer
2014-06-02 9:50 [PATCH] Remove two cancel_delayed_work() calls from the mid-layer Bart Van Assche
@ 2014-06-02 9:51 ` Hannes Reinecke
2014-06-02 11:32 ` Christoph Hellwig
1 sibling, 0 replies; 3+ messages in thread
From: Hannes Reinecke @ 2014-06-02 9:51 UTC (permalink / raw)
To: Bart Van Assche, James Bottomley, Christoph Hellwig
Cc: Paolo Bonzini, Jens Axboe, Joe Lawrence,
linux-scsi@vger.kernel.org
On 06/02/2014 11:50 AM, Bart Van Assche wrote:
> scsi_put_command() is either invoked before blk_start_request() or
> after block layer processing has completed. scsi_cmnd.abort_work
> is scheduled from inside the SCSI timeout handler. The block layer
> guarantees that either the regular completion handler
> (softirq_done_fn()) or the timeout handler (rq_timed_out_fn()) is
> invoked but not both. This means that scsi_put_command() is never
> invoked while abort_work is scheduled. Hence remove the
> cancel_delayed_work() call from scsi_put_command().
>
> Similarly, scsi_abort_command() is only invoked from the SCSI
> timeout handler. If scsi_abort_command() is invoked for a SCSI
> command with the SCSI_EH_ABORT_SCHEDULED flag set this means that
> scmd_eh_abort_handler() has already invoked scsi_queue_insert() and
> hence that scsi_cmnd.abort_work is no longer pending. Hence also
> remove the cancel_delayed_work() call from scsi_abort_command().
>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> Cc: Hannes Reinecke <hare@suse.de>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Jens Axboe <axboe@fb.com>
> Cc: Joe Lawrence <jdl1291@gmail.com>
> ---
> drivers/scsi/scsi.c | 2 +-
> drivers/scsi/scsi_error.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
> index 88d46fe..53b8b94 100644
> --- a/drivers/scsi/scsi.c
> +++ b/drivers/scsi/scsi.c
> @@ -334,7 +334,7 @@ void scsi_put_command(struct scsi_cmnd *cmd)
> list_del_init(&cmd->list);
> spin_unlock_irqrestore(&cmd->device->list_lock, flags);
>
> - cancel_delayed_work(&cmd->abort_work);
> + BUG_ON(delayed_work_pending(&cmd->abort_work));
>
> __scsi_put_command(cmd->device->host, cmd);
> }
> diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
> index f17aa7a..919ade2 100644
> --- a/drivers/scsi/scsi_error.c
> +++ b/drivers/scsi/scsi_error.c
> @@ -193,7 +193,7 @@ scsi_abort_command(struct scsi_cmnd *scmd)
> SCSI_LOG_ERROR_RECOVERY(3,
> scmd_printk(KERN_INFO, scmd,
> "scmd %p previous abort failed\n", scmd));
> - cancel_delayed_work(&scmd->abort_work);
> + BUG_ON(delayed_work_pending(&scmd->abort_work));
> return FAILED;
> }
>
>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@suse.de +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] Remove two cancel_delayed_work() calls from the mid-layer
2014-06-02 9:50 [PATCH] Remove two cancel_delayed_work() calls from the mid-layer Bart Van Assche
2014-06-02 9:51 ` Hannes Reinecke
@ 2014-06-02 11:32 ` Christoph Hellwig
1 sibling, 0 replies; 3+ messages in thread
From: Christoph Hellwig @ 2014-06-02 11:32 UTC (permalink / raw)
To: Bart Van Assche
Cc: James Bottomley, Christoph Hellwig, Hannes Reinecke,
Paolo Bonzini, Jens Axboe, Joe Lawrence,
linux-scsi@vger.kernel.org
On Mon, Jun 02, 2014 at 11:50:52AM +0200, Bart Van Assche wrote:
> scsi_put_command() is either invoked before blk_start_request() or
> after block layer processing has completed. scsi_cmnd.abort_work
> is scheduled from inside the SCSI timeout handler. The block layer
> guarantees that either the regular completion handler
> (softirq_done_fn()) or the timeout handler (rq_timed_out_fn()) is
> invoked but not both. This means that scsi_put_command() is never
> invoked while abort_work is scheduled. Hence remove the
> cancel_delayed_work() call from scsi_put_command().
>
> Similarly, scsi_abort_command() is only invoked from the SCSI
> timeout handler. If scsi_abort_command() is invoked for a SCSI
> command with the SCSI_EH_ABORT_SCHEDULED flag set this means that
> scmd_eh_abort_handler() has already invoked scsi_queue_insert() and
> hence that scsi_cmnd.abort_work is no longer pending. Hence also
> remove the cancel_delayed_work() call from scsi_abort_command().
>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 3+ messages in thread
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