cciss: Add lunid attribute to each logical drive in /sys

Add lunid attribute to each logical drive at
/sys/devices/<dev>/ccissX/cXdY/lunid for controller X,
logical drive Y

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 33 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-pci-devices-cciss b/Documentation/ABI/testing/sysfs-bus-pci-devices-cciss
index ac3429def235..5a6c8d36afc4 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci-devices-cciss
+++ b/Documentation/ABI/testing/sysfs-bus-pci-devices-cciss
@@ -38,3 +38,10 @@ Kernel Version:	2.6.31
 Contact:        iss_storagedev@hp.com
 Description:    Kicks of a rescan of the controller to discover logical
                 drive topology changes.
+
+Where:          /sys/bus/pci/devices/<dev>/ccissX/cXdY/lunid
+Date:           August 2009
+Kernel Version: 2.6.31
+Contact:        iss_storagedev@hp.com
+Description:    Displays the 8-byte LUN ID used to address logical
+                drive Y of controller X.
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 79afca2e824f..ae0cb1329e92 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -579,6 +579,31 @@ static ssize_t dev_show_rev(struct device *dev,
 }
 DEVICE_ATTR(rev, S_IRUGO, dev_show_rev, NULL);
 
+static ssize_t cciss_show_lunid(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        drive_info_struct *drv = dev_get_drvdata(dev);
+        struct ctlr_info *h = to_hba(drv->dev->parent);
+        unsigned long flags;
+        unsigned char lunid[8];
+
+        spin_lock_irqsave(CCISS_LOCK(h->ctlr), flags);
+        if (h->busy_configuring) {
+                spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
+                return -EBUSY;
+        }
+        if (!drv->heads) {
+                spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
+                return -ENOTTY;
+        }
+        memcpy(lunid, drv->LunID, sizeof(lunid));
+        spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
+        return snprintf(buf, 20, "0x%02x%02x%02x%02x%02x%02x%02x%02x\n",
+                lunid[0], lunid[1], lunid[2], lunid[3],
+                lunid[4], lunid[5], lunid[6], lunid[7]);
+}
+DEVICE_ATTR(lunid, S_IRUGO, cciss_show_lunid, NULL);
+
 static struct attribute *cciss_host_attrs[] = {
         &dev_attr_rescan.attr,
         NULL
@@ -604,6 +629,7 @@ static struct attribute *cciss_dev_attrs[] = {
         &dev_attr_model.attr,
         &dev_attr_vendor.attr,
         &dev_attr_rev.attr,
+        &dev_attr_lunid.attr,
         NULL
 };