SCSI: mpt2sas: Release spinlock for the raid device list before blocking it

commit 30c43282f3d347f47f9e05199d2b14f56f3f2837 upstream.

Added code to release the spinlock that is used to protect the
raid device list before calling a function that can block. The
blocking was causing a reschedule, and subsequently it is tried
to acquire the same lock, resulting in a panic (NMI Watchdog
detecting a CPU lockup).

Signed-off-by: Nagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index c79857e..2a4719a 100644 (file)
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -6425,6 +6425,7 @@ _scsih_mark_responding_raid_device(struct MPT2SAS_ADAPTER *ioc, u64 wwid,
                        } else
                                sas_target_priv_data = NULL;
                        raid_device->responding = 1;
+                       spin_unlock_irqrestore(&ioc->raid_device_lock, flags);
                        starget_printk(KERN_INFO, raid_device->starget,
                            "handle(0x%04x), wwid(0x%016llx)\n", handle,
                            (unsigned long long)raid_device->wwid);
@@ -6435,16 +6436,16 @@ _scsih_mark_responding_raid_device(struct MPT2SAS_ADAPTER *ioc, u64 wwid,
                         */
                        _scsih_init_warpdrive_properties(ioc, raid_device);
                        if (raid_device->handle == handle)
-                               goto out;
+                               return;
                        printk(KERN_INFO "\thandle changed from(0x%04x)!!!\n",
                            raid_device->handle);
                        raid_device->handle = handle;
                        if (sas_target_priv_data)
                                sas_target_priv_data->handle = handle;
-                       goto out;
+                       return;
                }
        }
- out:
+
        spin_unlock_irqrestore(&ioc->raid_device_lock, flags);
 }