Re: [PATCH] mpt3sas: Do scsi_remove_host() before deleting SAS PHY objects
rphan what lies beneath it: >> > >> > [ 955.119328] kobject: '6:0:0:0' (88074e2e1008): kobject_uevent_env >> > [ 955.133890] kobject: '6:0:0:0' (88074e2e1008): fill_kobj_path: path >> > = '/end_device-6:0:0/target6:0:0/6:0:0:0/bsg/6:0:0:0' >> > >> >> [Sreekanth] Calvin, Now with your patch we are observing same type of >> while unregistered the drive with scsi_transport layer >> after calling scsi_remove_host() on the same driver unload path, >> >> kobject: 'end_device-2:0' (8800dad0c010): kobject_uevent_env >> kobject: 'end_device-2:0' (8800dad0c010): fill_kobj_path: path = >> '/host2/port-2:0/end_device-2:0/bsg/end_device-2:0' >> >> As scsi_remove_host() has freed it's parent >> "/devices/pci:00/:00:07.0" we are observing these warnings. >> >> here is it's complete path >> >> fill_kobj_path: path = >> '/devices/pci:00/:00:07.0/host2/port-2:0/end_device-2:0/bsg/end_device-2:0', > > Could you post the stacktraces for your WARN/OOPS? > >> Until on ~3.19/4.0 kernel all the thing are working fine, we haven't >> seen these types of kernel warning. Also we haven't done any changes >> in mpt3sas driver w.r.t to this after 4.0 kernel. > > I'll dig around more. In any case, my patch seems to be papering over > the problem rather than solving it, so we need a different fix. > > Thanks, > Calvin > >> > >> > As the above from CONFIG_DEBUG_KOBJECT suggests, "end_device-6:0:0" no >> > longer >> > has a parent. The path to the enclosured device is: >> > >> > /sys/devices/pci:00/:00:01.0/:01:00.0/host6/port-6:0/expander-6:0/port-6:0:15/end_device-6:0:15/target6:0:15/6:0:15:0/enclosure/6:0:15:0/ArrayDevice09 >> > >> > Enclosure wants to re-add the device outside the enclosure: >> > >> > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/misc/enclosure.c#n404 >> > >> > We melt when trying to re-add "ArrayDevice09" to the "6:0:15:0" directory >> > above the "enclosure" directory best I can tell. This is *incredibly* >> > confusing because kobj_add_internal() actually clobbers the parent pointer >> > if it's NULL: >> > >> > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/lib/kobject.c#n216 >> > >> > So even though it appears that the parent was "6:0:15:0" here, it was >> > actually NULL when passed into kobj_add_internal(). Thus, we try to do >> > the add with the kset as our parent, and we get -ENOENT because that >> > node has been marked as inactive in kernfs as per here: >> > >> > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/fs/kernfs/dir.c#n743 >> > >> > Why is it inactive? I think, because __kernfs_remove() deleted an ancestor: >> > >> > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/fs/kernfs/dir.c#n1243 >> > >> > ...which brings us full circle. >> > >> >> Doesn't this need to be taken care in enclosure_removal? >> > >> > Even with enclosure compiled out, I still get a WARN like the following >> > for every block device being removed at rmmod (-dirty here is just from me >> > applying a fix to SES I sent to the list a few days ago): >> > >> > [ 224.057286] [ cut here ] >> > [ 224.067696] WARNING: CPU: 1 PID: 5412 at fs/sysfs/group.c:237 >> > sysfs_remove_group+0x10f/0x150 >> > [ 224.088007] sysfs group 83109ba0 not found for kobject 'sdc' >> > [ 224.102283] Modules linked in: mpt3sas(-) >> > [ 224.200483] CPU: 0 PID: 5412 Comm: rmmod Not tainted 4.6.0-dirty #4 >> > [ 224.219797] Hardware name: Wiwynn HoneyBadger/PantherPlus, BIOS >> > HBM6.71 02/03/2016 >> > [ 224.237001] ffff82af6280 8806e826f8b0 ffff81e13e54 >> > 8806e826f928 >> > [ 224.253811] 8806e826f8f8 81127822 >> > 831a5968 >> > [ 224.270647] 880600ed ed00dd04df21 >> > 880754ae3078 >> > [ 224.287462] Call Trace: >> > [ 224.292953] [] dump_stack+0x68/0x94 >> > [ 224.304433] [] __warn+0x172/0x1b0 >> > [ 224.315514] [] warn_slowpath_fmt+0x97/0xb0 >> > [ 224.351845] [] sysfs_remove_group+0x10f/0x150 >> > [ 224.36525
Re: [PATCH] mpt3sas: Do scsi_remove_host() before deleting SAS PHY objects
t; [ 224.200483] CPU: 0 PID: 5412 Comm: rmmod Not tainted 4.6.0-dirty #4
> > [ 224.219797] Hardware name: Wiwynn HoneyBadger/PantherPlus, BIOS
> > HBM6.71 02/03/2016
> > [ 224.237001] 82af6280 8806e826f8b0 81e13e54
> > 8806e826f928
> > [ 224.253811] 8806e826f8f8 81127822
> > 831a5968
> > [ 224.270647] 880600ed ed00dd04df21
> > 880754ae3078
> > [ 224.287462] Call Trace:
> > [ 224.292953] [] dump_stack+0x68/0x94
> > [ 224.304433] [] __warn+0x172/0x1b0
> > [ 224.315514] [] warn_slowpath_fmt+0x97/0xb0
> > [ 224.351845] [] sysfs_remove_group+0x10f/0x150
> > [ 224.365252] [] blk_trace_remove_sysfs+0x14/0x20
> > [ 224.379021] [] blk_unregister_queue+0xcf/0x120
> > [ 224.392589] [] del_gendisk+0x26e/0x600
> > [ 224.432345] [] sd_remove+0xf5/0x1b0
> > [ 224.443808] [] __device_release_driver+0x160/0x3a0
> > [ 224.458151] [] device_release_driver+0x25/0x40
> > [ 224.471734] [] bus_remove_device+0x2e1/0x4b0
> > [ 224.484926] [] device_del+0x37d/0x680
> > [ 224.555423] [] __scsi_remove_device+0x1e5/0x250
> > [ 224.569196] [] scsi_forget_host+0x12c/0x1e0
> > [ 224.582197] [] scsi_remove_host+0x10c/0x300
> > [ 224.595227] [] scsih_remove+0x339/0x670 [mpt3sas]
> > [ 224.609383] [] pci_device_remove+0x70/0x110
> > [ 224.622379] [] __device_release_driver+0x160/0x3a0
> > [ 224.636724] [] driver_detach+0x183/0x200
> > [ 224.649166] [] bus_remove_driver+0xdf/0x200
> > [ 224.662185] [] driver_unregister+0x67/0xa0
> > [ 224.675009] [] pci_unregister_driver+0x1e/0xe0
> > [ 224.688613] [] _mpt3sas_exit+0x23/0x5e9 [mpt3sas]
> > [ 224.702782] [] SyS_delete_module+0x2eb/0x390
> > [ 224.743359] [] entry_SYSCALL_64_fastpath+0x18/0xa8
> > [ 224.759036] ---[ end trace 13f1919bf2ec7bb0 ]---
> >
> > My patch fixes that too :)
> >
> > The only driver besides mpt*sas that calls sas_delete_port() explicitly is
> > HPSA, and it does it in the opposite order mpt3sas does: scsi_remove_host()
> > first.
> >
> > Thanks,
> > Calvin
> >
> >> -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 +, 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
Re: [PATCH] mpt3sas: Do scsi_remove_host() before deleting SAS PHY objects
[] blk_trace_remove_sysfs+0x14/0x20
> [ 224.379021] [] blk_unregister_queue+0xcf/0x120
> [ 224.392589] [] del_gendisk+0x26e/0x600
> [ 224.432345] [] sd_remove+0xf5/0x1b0
> [ 224.443808] [] __device_release_driver+0x160/0x3a0
> [ 224.458151] [] device_release_driver+0x25/0x40
> [ 224.471734] [] bus_remove_device+0x2e1/0x4b0
> [ 224.484926] [] device_del+0x37d/0x680
> [ 224.555423] [] __scsi_remove_device+0x1e5/0x250
> [ 224.569196] [] scsi_forget_host+0x12c/0x1e0
> [ 224.582197] [] scsi_remove_host+0x10c/0x300
> [ 224.595227] [] scsih_remove+0x339/0x670 [mpt3sas]
> [ 224.609383] [] pci_device_remove+0x70/0x110
> [ 224.622379] [] __device_release_driver+0x160/0x3a0
> [ 224.636724] [] driver_detach+0x183/0x200
> [ 224.649166] [] bus_remove_driver+0xdf/0x200
> [ 224.662185] [] driver_unregister+0x67/0xa0
> [ 224.675009] [] pci_unregister_driver+0x1e/0xe0
> [ 224.688613] [] _mpt3sas_exit+0x23/0x5e9 [mpt3sas]
> [ 224.702782] [] SyS_delete_module+0x2eb/0x390
> [ 224.743359] [] entry_SYSCALL_64_fastpath+0x18/0xa8
> [ 224.759036] ---[ end trace 13f1919bf2ec7bb0 ]---
>
> My patch fixes that too :)
>
> The only driver besides mpt*sas that calls sas_delete_port() explicitly is
> HPSA, and it does it in the opposite order mpt3sas does: scsi_remove_host()
> first.
>
> Thanks,
> Calvin
>
>> -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 +, 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
Re: [PATCH] mpt3sas: Do scsi_remove_host() before deleting SAS PHY objects
gt; 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 +, 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
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: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 +, 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
Re: [PATCH] mpt3sas: Do scsi_remove_host() before deleting SAS PHY objects
On Friday 05/13 at 21:17 +, 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
RE: [PATCH] mpt3sas: Do scsi_remove_host() before deleting SAS PHY objects
> -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.
*/
[PATCH] mpt3sas: Do scsi_remove_host() before deleting SAS PHY objects
On the hardware I'm testing on, simply removing the mpt3sas module
triggers a litany of WARNs culminating in an OOPS:
[ cut here ]
WARNING: CPU: 5 PID: 13348 at lib/kobject.c:244
kobject_add_internal+0x359/0x8a0
kobject_add_internal failed for ArrayDevice09 (error: -2 parent: 6:0:15:0)
CPU: 5 PID: 13348 Comm: rmmod Not tainted
4.6.0-rc2-mpt3sas-debug-1-g7e7e6f4 #2
Hardware name: Wiwynn HoneyBadger/PantherPlus, BIOS HBP6.6 11/20/2015
82b88ec0 8806ce76f820 81deff03 8806ce76f898
8806ce76f868 811191e2 880749819af8
00f4 ed00d9cedf0f 880749819b08 88074c9b8168
Call Trace:
[] dump_stack+0x67/0x94
[] __warn+0x172/0x1b0
[] warn_slowpath_fmt+0x97/0xb0
[] kobject_add_internal+0x359/0x8a0
[] kobject_add+0x10e/0x1c0
[] device_add+0x30a/0x1490
[] enclosure_remove_device+0x172/0x1cc [enclosure]
[] ses_intf_remove+0x1c4/0x270 [ses]
[] device_del+0x2ab/0x680
[] device_unregister+0x12/0x30
[] __scsi_remove_device+0x1d5/0x250
[] scsi_forget_host+0x12c/0x1e0
[] scsi_remove_host+0x10c/0x300
[] scsih_remove+0x321/0x680 [mpt3sas]
[] pci_device_remove+0x70/0x110
[] __device_release_driver+0x160/0x3a0
[] driver_detach+0x183/0x200
[] bus_remove_driver+0xdf/0x200
[] driver_unregister+0x67/0xa0
[] pci_unregister_driver+0x1e/0xe0
[] _mpt3sas_exit+0x23/0x219 [mpt3sas]
[] SyS_delete_module+0x2ee/0x390
[] entry_SYSCALL_64_fastpath+0x18/0xa8
---[ end trace fe163024b624f4af ]---
general protection fault: [#1] SMP KASAN
CPU: 6 PID: 17388 Comm: rmmod Tainted: GW
4.6.0-rc2-1-g7e7e6f4 #1
Hardware name: Wiwynn HoneyBadger/PantherPlus, BIOS HBP6.6 11/20/2015
task: 880753731740 ti: 8806896f task.ti: 8806896f
RIP: 0010:[] [] klist_put+0x1f/0x160
RSP: 0018:8806896f7a10 EFLAGS: 00010202
RAX: dc00 RBX: RCX: 880753731f48
RDX: 000b RSI: 0001 RDI: 0058
RBP: 8806896f7a30 R08: 0006 R09:
R10: R11: R12: 880752bec000
R13: 0001 R14: dc00 R15: 880752bec2b0
FS: 7feef8ea6700() GS:88075ef8() knlGS:
CS: 0010 DS: ES: CR0: 80050033
CR2: 7fe45044d020 CR3: 0006f7092000 CR4: 001006e0
Stack:
880752bec000 dc00
8806896f7a40 8290987e 8806896f7b00 820aa3bd
8806896f7aa0 1100d12def4f 880752bec390 829183ca
Call Trace:
[] klist_del+0xe/0x10
[] device_del+0x12d/0x680
[] device_unregister+0x12/0x30
[] enclosure_unregister+0xe0/0x170 [enclosure]
[] ses_intf_remove+0x190/0x270 [ses]
[] device_del+0x2ab/0x680
[] device_unregister+0x12/0x30
[] __scsi_remove_device+0x1d5/0x250
[] scsi_forget_host+0x12c/0x1e0
[] scsi_remove_host+0x10c/0x300
[] scsih_remove+0x321/0x680 [mpt3sas]
[] pci_device_remove+0x70/0x110
[] __device_release_driver+0x160/0x3a0
[] driver_detach+0x183/0x200
[] bus_remove_driver+0xdf/0x200
[] driver_unregister+0x67/0xa0
[] pci_unregister_driver+0x1e/0xe0
[] _mpt3sas_exit+0x23/0xa89 [mpt3sas]
[] SyS_delete_module+0x2ee/0x390
[] entry_SYSCALL_64_fastpath+0x18/0xa8
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().
Signed-off-by: Calvin Owens
---
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index e0e4920..4aa128a 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/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);
--
2.8.0.rc2
