Merge mulgrave-w:git/scsi-misc-2.6

[pandora-kernel.git] / drivers / s390 / block / dasd_devmap.c

diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index 9af02c7..91cf971 100644 (file)
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -258,8 +258,12 @@ dasd_parse_keyword( char *parsestring ) {
                 return residual_str;
         }
        if (strncmp("nopav", parsestring, length) == 0) {
-               dasd_nopav = 1;
-               MESSAGE(KERN_INFO, "%s", "disable PAV mode");
+               if (MACHINE_IS_VM)
+                       MESSAGE(KERN_INFO, "%s", "'nopav' not supported on VM");
+               else {
+                       dasd_nopav = 1;
+                       MESSAGE(KERN_INFO, "%s", "disable PAV mode");
+               }
                return residual_str;
        }
        if (strncmp("fixedbuffers", parsestring, length) == 0) {
@@ -523,17 +527,17 @@ dasd_create_device(struct ccw_device *cdev)
 {
        struct dasd_devmap *devmap;
        struct dasd_device *device;
+       unsigned long flags;
        int rc;
 
        devmap = dasd_devmap_from_cdev(cdev);
        if (IS_ERR(devmap))
                return (void *) devmap;
-       cdev->dev.driver_data = devmap;
 
        device = dasd_alloc_device();
        if (IS_ERR(device))
                return device;
-       atomic_set(&device->ref_count, 2);
+       atomic_set(&device->ref_count, 3);
 
        spin_lock(&dasd_devmap_lock);
        if (!devmap->device) {
@@ -552,6 +556,11 @@ dasd_create_device(struct ccw_device *cdev)
                dasd_free_device(device);
                return ERR_PTR(rc);
        }
+
+       spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+       cdev->dev.driver_data = device;
+       spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+
        return device;
 }
 
@@ -569,6 +578,7 @@ dasd_delete_device(struct dasd_device *device)
 {
        struct ccw_device *cdev;
        struct dasd_devmap *devmap;
+       unsigned long flags;
 
        /* First remove device pointer from devmap. */
        devmap = dasd_find_busid(device->cdev->dev.bus_id);
@@ -582,9 +592,16 @@ dasd_delete_device(struct dasd_device *device)
        devmap->device = NULL;
        spin_unlock(&dasd_devmap_lock);
 
-       /* Drop ref_count by 2, one for the devmap reference and
-        * one for the passed reference. */
-       atomic_sub(2, &device->ref_count);
+       /* Disconnect dasd_device structure from ccw_device structure. */
+       spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+       device->cdev->dev.driver_data = NULL;
+       spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+
+       /*
+        * Drop ref_count by 3, one for the devmap reference, one for
+        * the cdev reference and one for the passed reference.
+        */
+       atomic_sub(3, &device->ref_count);
 
        /* Wait for reference counter to drop to zero. */
        wait_event(dasd_delete_wq, atomic_read(&device->ref_count) == 0);
@@ -593,9 +610,6 @@ dasd_delete_device(struct dasd_device *device)
        cdev = device->cdev;
        device->cdev = NULL;
 
-       /* Disconnect dasd_devmap structure from ccw_device structure. */
-       cdev->dev.driver_data = NULL;
-
        /* Put ccw_device structure. */
        put_device(&cdev->dev);
 
@@ -613,23 +627,34 @@ dasd_put_device_wake(struct dasd_device *device)
        wake_up(&dasd_delete_wq);
 }
 
+/*
+ * Return dasd_device structure associated with cdev.
+ * This function needs to be called with the ccw device
+ * lock held. It can be used from interrupt context.
+ */
+struct dasd_device *
+dasd_device_from_cdev_locked(struct ccw_device *cdev)
+{
+       struct dasd_device *device = cdev->dev.driver_data;
+
+       if (!device)
+               return ERR_PTR(-ENODEV);
+       dasd_get_device(device);
+       return device;
+}
+
 /*
  * Return dasd_device structure associated with cdev.
  */
 struct dasd_device *
 dasd_device_from_cdev(struct ccw_device *cdev)
 {
-       struct dasd_devmap *devmap;
        struct dasd_device *device;
+       unsigned long flags;
 
-       device = ERR_PTR(-ENODEV);
-       spin_lock(&dasd_devmap_lock);
-       devmap = cdev->dev.driver_data;
-       if (devmap && devmap->device) {
-               device = devmap->device;
-               dasd_get_device(device);
-       }
-       spin_unlock(&dasd_devmap_lock);
+       spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+       device = dasd_device_from_cdev_locked(cdev);
+       spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
        return device;
 }
 
@@ -730,16 +755,17 @@ static ssize_t
 dasd_discipline_show(struct device *dev, struct device_attribute *attr,
                     char *buf)
 {
-       struct dasd_devmap *devmap;
-       char *dname;
+       struct dasd_device *device;
+       ssize_t len;
 
-       spin_lock(&dasd_devmap_lock);
-       dname = "none";
-       devmap = dev->driver_data;
-       if (devmap && devmap->device && devmap->device->discipline)
-               dname = devmap->device->discipline->name;
-       spin_unlock(&dasd_devmap_lock);
-       return snprintf(buf, PAGE_SIZE, "%s\n", dname);
+       device = dasd_device_from_cdev(to_ccwdev(dev));
+       if (!IS_ERR(device) && device->discipline) {
+               len = snprintf(buf, PAGE_SIZE, "%s\n",
+                              device->discipline->name);
+               dasd_put_device(device);
+       } else
+               len = snprintf(buf, PAGE_SIZE, "none\n");
+       return len;
 }
 
 static DEVICE_ATTR(discipline, 0444, dasd_discipline_show, NULL);