| Message ID | 1504171249-38053-1-git-send-email-hare@suse.de (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On 31/08/2017 10:20, Hannes Reinecke wrote: > (resending to include linux-scsi) > > When removing the HBA or port there's a device_del() inversion > in sas_deform_port(). > If there's only one phy it will call sas_unregister_domain_devices(), > which in turn might remove any phys and end_devices asynchronously > via the DISCE_DESTRUCT event. > But then it goes ahead and calls sas_port_delete() before the DISCE_DESTRUCT > event had a chance to run. > Consequently the port is removed before the phy, and we're getting > nasty kernel WARNING like > Hi Hannes, Your solution looks similar to what Dan tried originally to fix this, here: https://marc.info/?l=linux-scsi&m=143459794823595&w=2 As I recall, I was getting a NULL dereference with his. Anyway, have you tried removing a disk from an expander? I don't see how this is fixed-up in your patch. I quickly tested and I see the WARN. However just removing a directly attached disk looked ok. BTW, another colleague of mine has taken over the work we were doing on this topic. I reviewed internally the candidate patchset yesterday, and it still has a few issues; here's that patchset: https://github.com/JasonYanHuawei/linux-libsas All the best, John > WARNING: CPU: 14 PID: 1592 at fs/sysfs/group.c:237 device_del+0x61/0x2a0() > sysfs group ffffffff81eff140 not found for kobject '6:0:0:0' > > This patch moves the call to sas_port_delete() into the DISCE_DESTRUCT > handler to ensure that devices are removed in the correct order. > > Signed-off-by: Hannes Reinecke <hare@suse.com> > --- > drivers/scsi/libsas/sas_discover.c | 10 +++++++++- > drivers/scsi/libsas/sas_port.c | 6 ++---- > 2 files changed, 11 insertions(+), 5 deletions(-) > > diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c > index 60de662..dc8f789 100644 > --- a/drivers/scsi/libsas/sas_discover.c > +++ b/drivers/scsi/libsas/sas_discover.c > @@ -368,6 +368,10 @@ static void sas_destruct_devices(struct work_struct *work) > sas_rphy_delete(dev->rphy); > sas_unregister_common_dev(port, dev); > } > + if (!port->port->rphy) { > + sas_port_delete(port->port); > + port->port = NULL; > + } > } > > void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev) > @@ -401,8 +405,12 @@ void sas_unregister_domain_devices(struct asd_sas_port *port, int gone) > list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) > sas_unregister_dev(port, dev); > > + /* > + * Add another destruct event (or overload the existing one) > + * to trigger port deletion. > + */ > port->port->rphy = NULL; > - > + sas_discover_event(port, DISCE_DESTRUCT); > } > > void sas_device_set_phy(struct domain_device *dev, struct sas_port *port) > diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c > index d3c5297..7ee0c0a 100644 > --- a/drivers/scsi/libsas/sas_port.c > +++ b/drivers/scsi/libsas/sas_port.c > @@ -217,11 +217,9 @@ void sas_deform_port(struct asd_sas_phy *phy, int gone) > if (dev) > dev->pathways--; > > - if (port->num_phys == 1) { > + if (port->num_phys == 1) > sas_unregister_domain_devices(port, gone); > - sas_port_delete(port->port); > - port->port = NULL; > - } else { > + else { > sas_port_delete_phy(port->port, phy->phy); > sas_device_set_phy(dev, port->port); > } >
diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c index 60de662..dc8f789 100644 --- a/drivers/scsi/libsas/sas_discover.c +++ b/drivers/scsi/libsas/sas_discover.c @@ -368,6 +368,10 @@ static void sas_destruct_devices(struct work_struct *work) sas_rphy_delete(dev->rphy); sas_unregister_common_dev(port, dev); } + if (!port->port->rphy) { + sas_port_delete(port->port); + port->port = NULL; + } } void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev) @@ -401,8 +405,12 @@ void sas_unregister_domain_devices(struct asd_sas_port *port, int gone) list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) sas_unregister_dev(port, dev); + /* + * Add another destruct event (or overload the existing one) + * to trigger port deletion. + */ port->port->rphy = NULL; - + sas_discover_event(port, DISCE_DESTRUCT); } void sas_device_set_phy(struct domain_device *dev, struct sas_port *port) diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c index d3c5297..7ee0c0a 100644 --- a/drivers/scsi/libsas/sas_port.c +++ b/drivers/scsi/libsas/sas_port.c @@ -217,11 +217,9 @@ void sas_deform_port(struct asd_sas_phy *phy, int gone) if (dev) dev->pathways--; - if (port->num_phys == 1) { + if (port->num_phys == 1) sas_unregister_domain_devices(port, gone); - sas_port_delete(port->port); - port->port = NULL; - } else { + else { sas_port_delete_phy(port->port, phy->phy); sas_device_set_phy(dev, port->port); }
(resending to include linux-scsi) When removing the HBA or port there's a device_del() inversion in sas_deform_port(). If there's only one phy it will call sas_unregister_domain_devices(), which in turn might remove any phys and end_devices asynchronously via the DISCE_DESTRUCT event. But then it goes ahead and calls sas_port_delete() before the DISCE_DESTRUCT event had a chance to run. Consequently the port is removed before the phy, and we're getting nasty kernel WARNING like WARNING: CPU: 14 PID: 1592 at fs/sysfs/group.c:237 device_del+0x61/0x2a0() sysfs group ffffffff81eff140 not found for kobject '6:0:0:0' This patch moves the call to sas_port_delete() into the DISCE_DESTRUCT handler to ensure that devices are removed in the correct order. Signed-off-by: Hannes Reinecke <hare@suse.com> --- drivers/scsi/libsas/sas_discover.c | 10 +++++++++- drivers/scsi/libsas/sas_port.c | 6 ++---- 2 files changed, 11 insertions(+), 5 deletions(-)