[24/90] SCSI: mpt2sas: Release spinlock for the raid device list before blocking it

From: Greg KH
Date: Mon Jan 23 2012 - 19:01:02 EST


3.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: "nagalakshmi.nandigama@xxxxxxx" <nagalakshmi.nandigama@xxxxxxx>

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@xxxxxxx>
Signed-off-by: James Bottomley <JBottomley@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/scsi/mpt2sas/mpt2sas_scsih.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -6425,6 +6425,7 @@ _scsih_mark_responding_raid_device(struc
} 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(struc
*/
_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);
}



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