[SCSI] mpt2sas: Fix for system hang when discovery in progress

Fix for issue : While discovery is in progress, hot unplug and hot plug of
enclosure connected to the controller card is causing system to hang.

When a device is in the process of being detected at driver load time then
if it is removed, the device that is no longer present will not be added
to the list. So the code in _scsih_probe_sas() is rearranged as such so
the devices that failed to be detected are not added to the list.

Signed-off-by: Nagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index 7a3865d9c959a1d7fd58cb51a5083666c5af83a5..c13efc3268d8eb3bdf9389339c2b1f23eb427c9d 100644 (file)
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -7657,22 +7657,27 @@ _scsih_probe_sas(struct MPT2SAS_ADAPTER *ioc)
        /* SAS Device List */
        list_for_each_entry_safe(sas_device, next, &ioc->sas_device_init_list,
            list) {
-               spin_lock_irqsave(&ioc->sas_device_lock, flags);
-               list_move_tail(&sas_device->list, &ioc->sas_device_list);
-               spin_unlock_irqrestore(&ioc->sas_device_lock, flags);
 
                if (ioc->hide_drives)
                        continue;
 
                if (!mpt2sas_transport_port_add(ioc, sas_device->handle,
                    sas_device->sas_address_parent)) {
-                       _scsih_sas_device_remove(ioc, sas_device);
+                       list_del(&sas_device->list);
+                       kfree(sas_device);
+                       continue;
                } else if (!sas_device->starget) {
                        mpt2sas_transport_port_remove(ioc,
                            sas_device->sas_address,
                            sas_device->sas_address_parent);
-                       _scsih_sas_device_remove(ioc, sas_device);
+                       list_del(&sas_device->list);
+                       kfree(sas_device);
+                       continue;
+
                }
+               spin_lock_irqsave(&ioc->sas_device_lock, flags);
+               list_move_tail(&sas_device->list, &ioc->sas_device_list);
+               spin_unlock_irqrestore(&ioc->sas_device_lock, flags);
        }
 }