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:calvinow...@fb.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....@broadcom.com; linux-s...@vger.kernel.org; linux-kernel@vger.kernel.org; kernel-t...@fb.com; calvinow...@fb.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-ow...@vger.kernel.org [mailto:linux-kernel- > > ow...@vger.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
