[PATCH] libata: hold host_set lock while finishing internal qc

Hold host_set lock while finishing internal qc.
Signed-off-by: NTejun Heo <htejun@gmail.com>

drivers/scsi/libata-core.c

@@ -1031,6 +1031,9 @@ unsigned ata_exec_internal(struct ata_port *ap, struct ata_device *dev,
 		spin_unlock_irqrestore(&ap->host_set->lock, flags);
 	}
 
+	/* finish up */
+	spin_lock_irqsave(&ap->host_set->lock, flags);
+
 	*tf = qc->tf;
 	err_mask = qc->err_mask;
 
@@ -1052,6 +1055,8 @@ unsigned ata_exec_internal(struct ata_port *ap, struct ata_device *dev,
 		ata_port_probe(ap);
 	}
 
+	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
 	return err_mask;
 }