staging: ion: Create separate heap and client debugfs directories

It can be slightly annoying to figure out which files under the ion
debugfs directory are heap debug files and which ones are client debug
files. Create separate subdirectories under ion to hold the different
types of debug files.

Cc: Colin Cross <ccross@android.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
[jstultz: Minor commit subject tweaks]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/ion/ion.c

@@ -60,6 +60,8 @@ struct ion_device {
 			     unsigned long arg);
 	struct rb_root clients;
 	struct dentry *debug_root;
+	struct dentry *heaps_debug_root;
+	struct dentry *clients_debug_root;
 };
 
 /**
@@ -764,8 +766,15 @@ struct ion_client *ion_client_create(struct ion_device *dev,
 
 	snprintf(debug_name, 64, "%u", client->pid);
 	client->debug_root = debugfs_create_file(debug_name, 0664,
-						 dev->debug_root, client,
-						 &debug_client_fops);
+						dev->clients_debug_root,
+						client, &debug_client_fops);
+	if (!client->debug_root) {
+		char buf[256], *path;
+		path = dentry_path(dev->clients_debug_root, buf, 256);
+		pr_err("Failed to create client debugfs at %s/%s\n",
+			path, debug_name);
+	}
+
 	up_write(&dev->lock);
 
 	return client;
@@ -1442,6 +1451,8 @@ DEFINE_SIMPLE_ATTRIBUTE(debug_shrink_fops, debug_shrink_get,
 
 void ion_device_add_heap(struct ion_device *dev, struct ion_heap *heap)
 {
+	struct dentry *debug_file;
+
 	if (!heap->ops->allocate || !heap->ops->free || !heap->ops->map_dma ||
 	    !heap->ops->unmap_dma)
 		pr_err("%s: can not add heap with invalid ops struct.\n",
@@ -1456,15 +1467,31 @@ void ion_device_add_heap(struct ion_device *dev, struct ion_heap *heap)
 	   the list later attempt higher id numbers first */
 	plist_node_init(&heap->node, -heap->id);
 	plist_add(&heap->node, &dev->heaps);
-	debugfs_create_file(heap->name, 0664, dev->debug_root, heap,
-			    &debug_heap_fops);
+	debug_file = debugfs_create_file(heap->name, 0664,
+					dev->heaps_debug_root, heap,
+					&debug_heap_fops);
+
+	if (!debug_file) {
+		char buf[256], *path;
+		path = dentry_path(dev->heaps_debug_root, buf, 256);
+		pr_err("Failed to create heap debugfs at %s/%s\n",
+			path, heap->name);
+	}
+
 #ifdef DEBUG_HEAP_SHRINKER
 	if (heap->shrinker.shrink) {
 		char debug_name[64];
 
 		snprintf(debug_name, 64, "%s_shrink", heap->name);
-		debugfs_create_file(debug_name, 0644, dev->debug_root, heap,
-				    &debug_shrink_fops);
+		debug_file = debugfs_create_file(
+			debug_name, 0644, dev->heaps_debug_root, heap,
+			&debug_shrink_fops);
+		if (!debug_file) {
+			char buf[256], *path;
+			path = dentry_path(dev->heaps_debug_root, buf, 256);
+			pr_err("Failed to create heap shrinker debugfs at %s/%s\n",
+				path, debug_name);
+		}
 	}
 #endif
 	up_write(&dev->lock);
@@ -1493,8 +1520,21 @@ struct ion_device *ion_device_create(long (*custom_ioctl)
 	}
 
 	idev->debug_root = debugfs_create_dir("ion", NULL);
-	if (!idev->debug_root)
-		pr_err("ion: failed to create debug files.\n");
+	if (!idev->debug_root) {
+		pr_err("ion: failed to create debugfs root directory.\n");
+		goto debugfs_done;
+	}
+	idev->heaps_debug_root = debugfs_create_dir("heaps", idev->debug_root);
+	if (!idev->heaps_debug_root) {
+		pr_err("ion: failed to create debugfs heaps directory.\n");
+		goto debugfs_done;
+	}
+	idev->clients_debug_root = debugfs_create_dir("clients",
+						idev->debug_root);
+	if (!idev->clients_debug_root)
+		pr_err("ion: failed to create debugfs clients directory.\n");
+
+debugfs_done:
 
 	idev->custom_ioctl = custom_ioctl;
 	idev->buffers = RB_ROOT;
@@ -1508,6 +1548,7 @@ struct ion_device *ion_device_create(long (*custom_ioctl)
 void ion_device_destroy(struct ion_device *dev)
 {
 	misc_deregister(&dev->dev);
+	debugfs_remove_recursive(dev->debug_root);
 	/* XXX need to free the heaps and clients ? */
 	kfree(dev);
 }