svn commit: r249611 - in stable/9/sys/cam: ata scsi

Scott Long scott4long at yahoo.com
Thu Apr 25 00:33:10 UTC 2013


On Apr 23, 2013, at 12:02 AM, Alexander Motin <mav at FreeBSD.org> wrote:

> On 23.04.2013 05:35, Scott Long wrote:
>> What problem does this solve, other than to unintentionally break the MPT driver?  This needs to be backed out of HEAD and stable/9 until a better analysis is done.
> 
> It depends on definition of "problem". I don't think that polling in a tight loop is a right way to do anything while system is operational.
> 

Breaking a common storage controller for nothing more than aesthetic reasons is a problem.  I'd like you to discuss and review this stuff more.  Please.  Pretty, pretty please.

> Search through the sources shows that the only two drivers doing nasty things on shutdown_post_sync are mpt and hptmv.  While hptmv really shuts worker thread down there, mpt just disables interrupts breaking normal operation. That situation looks quite dirty to me. From one side if controller really needs shutdown (to flush some caches, etc), then it should not receive any (or reject all) commands after that point (either polled or not). If it doesn't need shutdown, then what for are these shaman dances?
> 

You'll need to talk to Gibbs about MPT.  I committed the code as a proxy for him; I don't recall why he specifically wanted to shut down interrupts there.  Talking to him would be a good pre-commit action.

> Instead of revert, I propose this trivial non-invasive patch to fix the problem by moving hptmv and mpt shutdown a bit later in shutdown order: http://people.freebsd.org/~mav/post_sync.patch
> 

I'm fine with the concept, so long as it works.  Have you tested it?

(btw, sorry I missed this response earlier)

Thanks,
Scott

>> On Apr 18, 2013, at 3:44 AM, Alexander Motin <mav at FreeBSD.org> wrote:
>> 
>>> Author: mav
>>> Date: Thu Apr 18 09:44:00 2013
>>> New Revision: 249611
>>> URL: http://svnweb.freebsd.org/changeset/base/249611
>>> 
>>> Log:
>>>  MFC r248872, r249048:
>>>  Make pre-shutdown flush and spindown routines to not use xpt_polled_action(),
>>>  but execute the commands in regular way.  There is no any reason to cook CPU
>>>  while the system is still fully operational.  After this change polling in
>>>  CAM is used only for kernel dumping.
>>> 
>>> Modified:
>>>  stable/9/sys/cam/ata/ata_da.c
>>>  stable/9/sys/cam/scsi/scsi_da.c
>>> Directory Properties:
>>>  stable/9/sys/   (props changed)
>>> 
>>> Modified: stable/9/sys/cam/ata/ata_da.c
>>> ==============================================================================
>>> --- stable/9/sys/cam/ata/ata_da.c	Thu Apr 18 09:40:34 2013	(r249610)
>>> +++ stable/9/sys/cam/ata/ata_da.c	Thu Apr 18 09:44:00 2013	(r249611)
>>> @@ -1825,11 +1825,10 @@ adaflush(void)
>>> {
>>> 	struct cam_periph *periph;
>>> 	struct ada_softc *softc;
>>> +	union ccb *ccb;
>>> 	int error;
>>> 
>>> 	CAM_PERIPH_FOREACH(periph, &adadriver) {
>>> -		union ccb ccb;
>>> -
>>> 		/* If we paniced with lock held - not recurse here. */
>>> 		if (cam_periph_owned(periph))
>>> 			continue;
>>> @@ -1845,10 +1844,8 @@ adaflush(void)
>>> 			continue;
>>> 		}
>>> 
>>> -		xpt_setup_ccb(&ccb.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
>>> -
>>> -		ccb.ccb_h.ccb_state = ADA_CCB_DUMP;
>>> -		cam_fill_ataio(&ccb.ataio,
>>> +		ccb = cam_periph_getccb(periph, CAM_PRIORITY_NORMAL);
>>> +		cam_fill_ataio(&ccb->ataio,
>>> 				    0,
>>> 				    adadone,
>>> 				    CAM_DIR_NONE,
>>> @@ -1856,20 +1853,17 @@ adaflush(void)
>>> 				    NULL,
>>> 				    0,
>>> 				    ada_default_timeout*1000);
>>> -
>>> 		if (softc->flags & ADA_FLAG_CAN_48BIT)
>>> -			ata_48bit_cmd(&ccb.ataio, ATA_FLUSHCACHE48, 0, 0, 0);
>>> +			ata_48bit_cmd(&ccb->ataio, ATA_FLUSHCACHE48, 0, 0, 0);
>>> 		else
>>> -			ata_28bit_cmd(&ccb.ataio, ATA_FLUSHCACHE, 0, 0, 0);
>>> -		xpt_polled_action(&ccb);
>>> +			ata_28bit_cmd(&ccb->ataio, ATA_FLUSHCACHE, 0, 0, 0);
>>> 
>>> -		error = cam_periph_error(&ccb,
>>> -		    0, SF_NO_RECOVERY | SF_NO_RETRY, NULL);
>>> -		if ((ccb.ccb_h.status & CAM_DEV_QFRZN) != 0)
>>> -			cam_release_devq(ccb.ccb_h.path, /*relsim_flags*/0,
>>> -			    /*reduction*/0, /*timeout*/0, /*getcount_only*/0);
>>> +		error = cam_periph_runccb(ccb, adaerror, /*cam_flags*/0,
>>> +		    /*sense_flags*/ SF_NO_RECOVERY | SF_NO_RETRY,
>>> +		    softc->disk->d_devstat);
>>> 		if (error != 0)
>>> 			xpt_print(periph->path, "Synchronize cache failed\n");
>>> +		xpt_release_ccb(ccb);
>>> 		cam_periph_unlock(periph);
>>> 	}
>>> }
>>> @@ -1879,11 +1873,10 @@ adaspindown(uint8_t cmd, int flags)
>>> {
>>> 	struct cam_periph *periph;
>>> 	struct ada_softc *softc;
>>> +	union ccb *ccb;
>>> 	int error;
>>> 
>>> 	CAM_PERIPH_FOREACH(periph, &adadriver) {
>>> -		union ccb ccb;
>>> -
>>> 		/* If we paniced with lock held - not recurse here. */
>>> 		if (cam_periph_owned(periph))
>>> 			continue;
>>> @@ -1900,10 +1893,8 @@ adaspindown(uint8_t cmd, int flags)
>>> 		if (bootverbose)
>>> 			xpt_print(periph->path, "spin-down\n");
>>> 
>>> -		xpt_setup_ccb(&ccb.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
>>> -
>>> -		ccb.ccb_h.ccb_state = ADA_CCB_DUMP;
>>> -		cam_fill_ataio(&ccb.ataio,
>>> +		ccb = cam_periph_getccb(periph, CAM_PRIORITY_NORMAL);
>>> +		cam_fill_ataio(&ccb->ataio,
>>> 				    0,
>>> 				    adadone,
>>> 				    CAM_DIR_NONE | flags,
>>> @@ -1911,17 +1902,14 @@ adaspindown(uint8_t cmd, int flags)
>>> 				    NULL,
>>> 				    0,
>>> 				    ada_default_timeout*1000);
>>> +		ata_28bit_cmd(&ccb->ataio, cmd, 0, 0, 0);
>>> 
>>> -		ata_28bit_cmd(&ccb.ataio, cmd, 0, 0, 0);
>>> -		xpt_polled_action(&ccb);
>>> -
>>> -		error = cam_periph_error(&ccb,
>>> -		    0, SF_NO_RECOVERY | SF_NO_RETRY, NULL);
>>> -		if ((ccb.ccb_h.status & CAM_DEV_QFRZN) != 0)
>>> -			cam_release_devq(ccb.ccb_h.path, /*relsim_flags*/0,
>>> -			    /*reduction*/0, /*timeout*/0, /*getcount_only*/0);
>>> +		error = cam_periph_runccb(ccb, adaerror, /*cam_flags*/0,
>>> +		    /*sense_flags*/ SF_NO_RECOVERY | SF_NO_RETRY,
>>> +		    softc->disk->d_devstat);
>>> 		if (error != 0)
>>> 			xpt_print(periph->path, "Spin-down disk failed\n");
>>> +		xpt_release_ccb(ccb);
>>> 		cam_periph_unlock(periph);
>>> 	}
>>> }
>>> 
>>> Modified: stable/9/sys/cam/scsi/scsi_da.c
>>> ==============================================================================
>>> --- stable/9/sys/cam/scsi/scsi_da.c	Thu Apr 18 09:40:34 2013	(r249610)
>>> +++ stable/9/sys/cam/scsi/scsi_da.c	Thu Apr 18 09:44:00 2013	(r249611)
>>> @@ -2834,11 +2834,10 @@ dashutdown(void * arg, int howto)
>>> {
>>> 	struct cam_periph *periph;
>>> 	struct da_softc *softc;
>>> +	union ccb *ccb;
>>> 	int error;
>>> 
>>> 	CAM_PERIPH_FOREACH(periph, &dadriver) {
>>> -		union ccb ccb;
>>> -
>>> 		cam_periph_lock(periph);
>>> 		softc = (struct da_softc *)periph->softc;
>>> 
>>> @@ -2852,10 +2851,8 @@ dashutdown(void * arg, int howto)
>>> 			continue;
>>> 		}
>>> 
>>> -		xpt_setup_ccb(&ccb.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
>>> -
>>> -		ccb.ccb_h.ccb_state = DA_CCB_DUMP;
>>> -		scsi_synchronize_cache(&ccb.csio,
>>> +		ccb = cam_periph_getccb(periph, CAM_PRIORITY_NORMAL);
>>> +		scsi_synchronize_cache(&ccb->csio,
>>> 				       /*retries*/0,
>>> 				       /*cbfcnp*/dadone,
>>> 				       MSG_SIMPLE_Q_TAG,
>>> @@ -2864,15 +2861,12 @@ dashutdown(void * arg, int howto)
>>> 				       SSD_FULL_SIZE,
>>> 				       60 * 60 * 1000);
>>> 
>>> -		xpt_polled_action(&ccb);
>>> -
>>> -		error = cam_periph_error(&ccb,
>>> -		    0, SF_NO_RECOVERY | SF_NO_RETRY | SF_QUIET_IR, NULL);
>>> -		if ((ccb.ccb_h.status & CAM_DEV_QFRZN) != 0)
>>> -			cam_release_devq(ccb.ccb_h.path, /*relsim_flags*/0,
>>> -			    /*reduction*/0, /*timeout*/0, /*getcount_only*/0);
>>> +		error = cam_periph_runccb(ccb, daerror, /*cam_flags*/0,
>>> +		    /*sense_flags*/ SF_NO_RECOVERY | SF_NO_RETRY | SF_QUIET_IR,
>>> +		    softc->disk->d_devstat);
>>> 		if (error != 0)
>>> 			xpt_print(periph->path, "Synchronize cache failed\n");
>>> +		xpt_release_ccb(ccb);
>>> 		cam_periph_unlock(periph);
>>> 	}
>>> }
>> 
> 
> 
> -- 
> Alexander Motin



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