staging: most: configfs: add code for link removal

This patch adds code that cleans up established links whenever the destroy
attribute is set or if the config_item (directory) is being removed.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/most/configfs.c b/drivers/staging/most/configfs.c
index b622d27387a354909c6b288c31c08f170771f28e..934fb6d668a59d3f654b1d748658a982906585a8 100644 (file)
--- a/drivers/staging/most/configfs.c
+++ b/drivers/staging/most/configfs.c
@@ -16,6 +16,7 @@ struct mdev_link {
        struct config_item item;
        struct list_head list;
        bool create_link;
+       bool destroy_link;
        u16 num_buffers;
        u16 buffer_size;
        u16 subbuffer_size;
@@ -132,8 +133,7 @@ static ssize_t mdev_link_create_link_store(struct config_item *item,
        if (ret)
                return ret;
        if (!tmp)
-               return most_remove_link(mdev_link->device, mdev_link->channel,
-                                       mdev_link->comp);
+               return count;
        ret = set_config_and_add_link(mdev_link);
        if (ret && ret != -ENODEV)
                return ret;
@@ -142,6 +142,28 @@ static ssize_t mdev_link_create_link_store(struct config_item *item,
        return count;
 }
 
+static ssize_t mdev_link_destroy_link_store(struct config_item *item,
+                                           const char *page, size_t count)
+{
+       struct mdev_link *mdev_link = to_mdev_link(item);
+       bool tmp;
+       int ret;
+
+       ret = kstrtobool(page, &tmp);
+       if (ret)
+               return ret;
+       if (!tmp)
+               return count;
+       mdev_link->destroy_link = tmp;
+       ret = most_remove_link(mdev_link->device, mdev_link->channel,
+                              mdev_link->comp);
+       if (ret)
+               return ret;
+       if (!list_empty(&mdev_link_list))
+               list_del(&mdev_link->list);
+       return count;
+}
+
 static ssize_t mdev_link_direction_show(struct config_item *item, char *page)
 {
        return snprintf(page, PAGE_SIZE, "%s\n", to_mdev_link(item)->direction);
@@ -326,6 +348,7 @@ static ssize_t mdev_link_dbr_size_store(struct config_item *item,
 }
 
 CONFIGFS_ATTR_WO(mdev_link_, create_link);
+CONFIGFS_ATTR_WO(mdev_link_, destroy_link);
 CONFIGFS_ATTR(mdev_link_, device);
 CONFIGFS_ATTR(mdev_link_, channel);
 CONFIGFS_ATTR(mdev_link_, comp);
@@ -340,6 +363,7 @@ CONFIGFS_ATTR(mdev_link_, dbr_size);
 
 static struct configfs_attribute *mdev_link_attrs[] = {
        &mdev_link_attr_create_link,
+       &mdev_link_attr_destroy_link,
        &mdev_link_attr_device,
        &mdev_link_attr_channel,
        &mdev_link_attr_comp,
@@ -356,6 +380,16 @@ static struct configfs_attribute *mdev_link_attrs[] = {
 
 static void mdev_link_release(struct config_item *item)
 {
+       struct mdev_link *mdev_link = to_mdev_link(item);
+       int ret;
+
+       if (!list_empty(&mdev_link_list)) {
+               ret = most_remove_link(mdev_link->device, mdev_link->channel,
+                                      mdev_link->comp);
+               if (ret && (ret != -ENODEV))
+                       pr_err("Removing link failed.\n");
+               list_del(&mdev_link->list);
+       }
        kfree(to_mdev_link(item));
 }