From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: [PATCH 3/3] Make SCSI error handler code easier to understand Date: Mon, 26 May 2014 17:15:41 +0200 Message-ID: <53835A9D.3090104@acm.org> References: <538359DB.9080601@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from albert.telenet-ops.be ([195.130.137.90]:46934 "EHLO albert.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752539AbaEZPPm (ORCPT ); Mon, 26 May 2014 11:15:42 -0400 In-Reply-To: <538359DB.9080601@acm.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley , Christoph Hellwig Cc: Hannes Reinecke , Jens Axboe , Paolo Bonzini , Joe Lawrence , "linux-scsi@vger.kernel.org" Every now and then someone asks how it is avoided that the SCSI error handler and the SCSI completion handler are invoked concurrently for the same SCSI command. Add a few WARN_ON_ONCE() statements that make it clear how this is avoided. Signed-off-by: Bart Van Assche Cc: Hannes Reinecke Cc: Paolo Bonzini Cc: Christoph Hellwig Cc: Jens Axboe Cc: Joe Lawrence --- drivers/scsi/scsi_error.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 5232583..aee0dc0 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -120,6 +120,8 @@ scmd_eh_abort_handler(struct work_struct *work) struct scsi_device *sdev = scmd->device; int rtn; + WARN_ON_ONCE(!blk_rq_completed(scmd->request)); + if (scsi_host_eh_past_deadline(sdev->host)) { SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, @@ -185,6 +187,8 @@ scsi_abort_command(struct scsi_cmnd *scmd) struct Scsi_Host *shost = sdev->host; unsigned long flags; + WARN_ON_ONCE(!blk_rq_completed(scmd->request)); + if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) { /* * Retry after abort failed, escalate to next level. @@ -237,6 +241,8 @@ int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag) unsigned long flags; int ret = 0; + WARN_ON_ONCE(!blk_rq_completed(scmd->request)); + if (!shost->ehandler) return 0; -- 1.8.4.5