lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 16 May 2016 15:51:48 -0600
From:	Sathya Prakash Veerichetty <sathya.prakash@...adcom.com>
To:	Calvin Owens <calvinowens@...com>,
	"Elliott, Robert (Persistent Memory)" <elliott@....com>
Cc:	Chaitra Basappa <chaitra.basappa@...adcom.com>,
	Suganath Prabu Subramani 
	<suganath-prabu.subramani@...adcom.com>,
	"James E.J. Bottomley" <jejb@...ux.vnet.ibm.com>,
	"Martin K. Petersen" <martin.petersen@...cle.com>,
	PDL-MPT-FUSIONLINUX <mpt-fusionlinux.pdl@...adcom.com>,
	linux-scsi@...r.kernel.org, linux-kernel@...r.kernel.org,
	kernel-team@...com
Subject: RE: [PATCH] mpt3sas: Do scsi_remove_host() before deleting SAS PHY objects

Our understanding is the relationship between the SCSI host and SAS end
devices is a parent-child and before ripping of SCSI host we need to rip of
all the children. Why the enclosure ends up trying to re-parent the SCSI
device from the enclosure to the SAS PHY even after we remove the SAS Phy?.
Doesn't this need to be taken care in enclosure_removal?

-----Original Message-----
From: Calvin Owens [mailto:calvinowens@...com]
Sent: Monday, May 16, 2016 2:25 PM
To: Elliott, Robert (Persistent Memory)
Cc: Sathya Prakash; Chaitra P B; Suganath Prabu Subramani; James E.J.
Bottomley; Martin K. Petersen; MPT-FusionLinux.pdl@...adcom.com;
linux-scsi@...r.kernel.org; linux-kernel@...r.kernel.org;
kernel-team@...com; calvinowens@...com
Subject: Re: [PATCH] mpt3sas: Do scsi_remove_host() before deleting SAS PHY
objects

On Friday 05/13 at 21:17 +0000, Elliott, Robert (Persistent Memory) wrote:
>
>
> > -----Original Message-----
> > From: linux-kernel-owner@...r.kernel.org [mailto:linux-kernel-
> > owner@...r.kernel.org] On Behalf Of Calvin Owens
> > Sent: Friday, May 13, 2016 3:28 PM
> ...
> > Subject: [PATCH] mpt3sas: Do scsi_remove_host() before deleting SAS
> > PHY objects
> >
> ...
> > The issue is that enclosure_remove_device() expects to be able to
> > re-add the device that was previously enclosured: so with SES
> > running, the order we unwind things matters in a way it otherwise
> > wouldn't.
> >
> > Since mpt3sas deletes the SAS objects before the SCSI hosts,
> > enclosure ends up trying to re-parent the SCSI device from the
> > enclosure to the SAS PHY which has already been deleted. This obviously
> > ends in sadness.
> >
> > The fix appears to be simple: just call scsi_remove_host() before we
> > call
> > sas_port_delete() and/or sas_remove_host().
> >
> ...
> > diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
> > @@ -8149,6 +8149,8 @@ void scsih_remove(struct pci_dev *pdev)
> >  		_scsih_raid_device_remove(ioc, raid_device);
> >  	}
> >
> > +	scsi_remove_host(shost);
> > +
> >  	/* free ports attached to the sas_host */
> >  	list_for_each_entry_safe(mpt3sas_port, next_port,
> >  	   &ioc->sas_hba.sas_port_list, port_list) { @@ -8172,7 +8174,6 @@
> > void scsih_remove(struct pci_dev *pdev)
> >  	}
> >
> >  	sas_remove_host(shost);
> > -	scsi_remove_host(shost);
> >  	mpt3sas_base_detach(ioc);
> >  	spin_lock(&gioc_lock);
> >  	list_del(&ioc->list);
>
> That change matches the pattern of all other drivers calling
> sas_remove_host, except for one:
> 	drivers/message/fusion/mptsas.c
>
> That consensus means this comment in drivers/scsi/scsi_transport_sas.c
> is wrong:
>
> /**
>  * sas_remove_host  -  tear down a Scsi_Host's SAS data structures
>  * @shost:      Scsi Host that is torn down
>  *
>  * Removes all SAS PHYs and remote PHYs for a given Scsi_Host.
>  * Must be called just before scsi_remove_host for SAS HBAs.
>  */

Yes, exactly: that comment appears to be backwards, and as you say most
drivers appear to do the opposite (I looked at HPSA at least, which calls
sas_port_delete() before scsi_remove_host()).

I suppose I should send a patch to fix the comment as well? It'd be nice to
get some testing to be certain I'm not breaking somebody else's setup by
fixing mine though...

Thanks,
Calvin

Powered by blists - more mailing lists