gpu: ion: make sure all clients are exposed in debugfs

Currently, if multiple Ion clients are created with the same name, only
the first one shows up in debugfs. Rectify this by adding a
monotonically-increasing serial number to the debug names of Ion
clients.

Change-Id: I000e45055d5029c7bccd88c36b238736929da3a5
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index 7627ffbc83600d655c53642915f78334a3d868b5..48774e3974aa02f13a4656541660f8f182549888 100644 (file)
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -71,6 +71,8 @@ struct ion_device {
  * @idr:               an idr space for allocating handle ids
  * @lock:              lock protecting the tree of handles
  * @name:              used for debugging
+ * @display_name:      used for debugging (unique version of @name)
+ * @display_serial:    used for debugging (to make display_name unique)
  * @task:              used for debugging
  *
  * A client represents a list of buffers this client may access.
@@ -84,6 +86,8 @@ struct ion_client {
        struct idr idr;
        struct mutex lock;
        const char *name;
+       char *display_name;
+       int display_serial;
        struct task_struct *task;
        pid_t pid;
        struct dentry *debug_root;
@@ -710,6 +714,21 @@ static const struct file_operations debug_client_fops = {
        .release = single_release,
 };
 
+static int ion_get_client_serial(const struct rb_root *root,
+                                       const unsigned char *name)
+{
+       int serial = -1;
+       struct rb_node *node;
+       for (node = rb_first(root); node; node = rb_next(node)) {
+               struct ion_client *client = rb_entry(node, struct ion_client,
+                                               node);
+               if (strcmp(client->name, name))
+                       continue;
+               serial = max(serial, client->display_serial);
+       }
+       return serial + 1;
+}
+
 struct ion_client *ion_client_create(struct ion_device *dev,
                                     const char *name)
 {
@@ -720,6 +739,11 @@ struct ion_client *ion_client_create(struct ion_device *dev,
        struct ion_client *entry;
        pid_t pid;
 
+       if (!name) {
+               pr_err("%s: Name cannot be null\n", __func__);
+               return ERR_PTR(-EINVAL);
+       }
+
        get_task_struct(current->group_leader);
        task_lock(current->group_leader);
        pid = task_pid_nr(current->group_leader);
@@ -748,6 +772,13 @@ struct ion_client *ion_client_create(struct ion_device *dev,
                goto err_free_client;
 
        down_write(&dev->lock);
+       client->display_serial = ion_get_client_serial(&dev->clients, name);
+       client->display_name = kasprintf(
+               GFP_KERNEL, "%s-%d", name, client->display_serial);
+       if (!client->display_name) {
+               up_write(&dev->lock);
+               goto err_free_client_name;
+       }
        p = &dev->clients.rb_node;
        while (*p) {
                parent = *p;
@@ -761,20 +792,22 @@ struct ion_client *ion_client_create(struct ion_device *dev,
        rb_link_node(&client->node, parent, p);
        rb_insert_color(&client->node, &dev->clients);
 
-       client->debug_root = debugfs_create_file(name, 0664,
+       client->debug_root = debugfs_create_file(client->display_name, 0664,
                                                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, name);
+                       path, client->display_name);
        }
 
        up_write(&dev->lock);
 
        return client;
 
+err_free_client_name:
+       kfree(client->name);
 err_free_client:
        kfree(client);
 err_put_task_struct:
@@ -805,6 +838,7 @@ void ion_client_destroy(struct ion_client *client)
        debugfs_remove_recursive(client->debug_root);
        up_write(&dev->lock);
 
+       kfree(client->display_name);
        kfree(client->name);
        kfree(client);
 }