Merge tag 'for-f2fs-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jaege...

[karo-tx-linux.git] / drivers / dax / device.c

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 12943d19bfc43ea17e6f2f92419c5a52ffa35f44..e9f3b3e4bbf45805d5288ad0d3ee03243c2a1af0 100644 (file)
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -529,7 +529,8 @@ static void dev_dax_release(struct device *dev)
        struct dax_region *dax_region = dev_dax->region;
        struct dax_device *dax_dev = dev_dax->dax_dev;
 
-       ida_simple_remove(&dax_region->ida, dev_dax->id);
+       if (dev_dax->id >= 0)
+               ida_simple_remove(&dax_region->ida, dev_dax->id);
        dax_region_put(dax_region);
        put_dax(dax_dev);
        kfree(dev_dax);
@@ -559,7 +560,7 @@ static void unregister_dev_dax(void *dev)
 }
 
 struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
-               struct resource *res, int count)
+               int id, struct resource *res, int count)
 {
        struct device *parent = dax_region->dev;
        struct dax_device *dax_dev;
@@ -567,7 +568,10 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
        struct inode *inode;
        struct device *dev;
        struct cdev *cdev;
-       int rc = 0, i;
+       int rc, i;
+
+       if (!count)
+               return ERR_PTR(-EINVAL);
 
        dev_dax = kzalloc(sizeof(*dev_dax) + sizeof(*res) * count, GFP_KERNEL);
        if (!dev_dax)
@@ -587,10 +591,16 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
        if (i < count)
                goto err_id;
 
-       dev_dax->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
-       if (dev_dax->id < 0) {
-               rc = dev_dax->id;
-               goto err_id;
+       if (id < 0) {
+               id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
+               dev_dax->id = id;
+               if (id < 0) {
+                       rc = id;
+                       goto err_id;
+               }
+       } else {
+               /* region provider owns @id lifetime */
+               dev_dax->id = -1;
        }
 
        /*
@@ -598,8 +608,10 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
         * device outside of mmap of the resulting character device.
         */
        dax_dev = alloc_dax(dev_dax, NULL, NULL);
-       if (!dax_dev)
+       if (!dax_dev) {
+               rc = -ENOMEM;
                goto err_dax;
+       }
 
        /* from here on we're committed to teardown via dax_dev_release() */
        dev = &dev_dax->dev;
@@ -620,7 +632,7 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
        dev->parent = parent;
        dev->groups = dax_attribute_groups;
        dev->release = dev_dax_release;
-       dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);
+       dev_set_name(dev, "dax%d.%d", dax_region->id, id);
 
        rc = cdev_device_add(cdev, dev);
        if (rc) {
@@ -636,7 +648,8 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
        return dev_dax;
 
  err_dax:
-       ida_simple_remove(&dax_region->ida, dev_dax->id);
+       if (dev_dax->id >= 0)
+               ida_simple_remove(&dax_region->ida, dev_dax->id);
  err_id:
        kfree(dev_dax);