ANDROID: sdcardfs: Refactor configfs interface

This refactors the configfs code to be more easily extended.
It will allow additional files to be added easily.

Bug: 34542611
Bug: 34262585
Change-Id: I73c9b0ae5ca7eb27f4ebef3e6807f088b512d539
Signed-off-by: Daniel Rosenberg <drosen@google.com>

diff --git a/fs/sdcardfs/packagelist.c b/fs/sdcardfs/packagelist.c
index dac5d0f7d2dec0517ba167a8a485ecc40c4a9bfc..7321aa609dcfcdc5c0d31cdf1795550ec51ff99d 100644 (file)
--- a/fs/sdcardfs/packagelist.c
+++ b/fs/sdcardfs/packagelist.c
@@ -220,39 +220,29 @@ static void packagelist_destroy(void)
        printk(KERN_INFO "sdcardfs: destroyed packagelist pkgld\n");
 }
 
-struct package_appid {
+struct package_details {
        struct config_item item;
-       int add_pid;
+       const char* name;
 };
 
-static inline struct package_appid *to_package_appid(struct config_item *item)
+static inline struct package_details *to_package_details(struct config_item *item)
 {
-       return item ? container_of(item, struct package_appid, item) : NULL;
+       return item ? container_of(item, struct package_details, item) : NULL;
 }
 
-static struct configfs_attribute package_appid_attr_add_pid = {
-       .ca_owner = THIS_MODULE,
-       .ca_name = "appid",
-       .ca_mode = S_IRUGO | S_IWUGO,
-};
-
-static struct configfs_attribute *package_appid_attrs[] = {
-       &package_appid_attr_add_pid,
-       NULL,
-};
+CONFIGFS_ATTR_STRUCT(package_details);
+#define PACKAGE_DETAILS_ATTR(_name, _mode, _show, _store)      \
+struct package_details_attribute package_details_attr_##_name = __CONFIGFS_ATTR(_name, _mode, _show, _store)
 
-static ssize_t package_appid_attr_show(struct config_item *item,
-                                     struct configfs_attribute *attr,
+static ssize_t package_details_appid_show(struct package_details *package_details,
                                      char *page)
 {
-       return scnprintf(page, PAGE_SIZE, "%u\n", get_appid(item->ci_name));
+       return scnprintf(page, PAGE_SIZE, "%u\n", get_appid(package_details->name));
 }
 
-static ssize_t package_appid_attr_store(struct config_item *item,
-                                      struct configfs_attribute *attr,
+static ssize_t package_details_appid_store(struct package_details *package_details,
                                       const char *page, size_t count)
 {
-       struct package_appid *package_appid = to_package_appid(item);
        unsigned int tmp;
        int ret;
 
@@ -260,73 +250,76 @@ static ssize_t package_appid_attr_store(struct config_item *item,
        if (ret)
                return ret;
 
-       ret = insert_packagelist_entry(item->ci_name, tmp);
-       package_appid->add_pid = tmp;
+       ret = insert_packagelist_entry(package_details->name, tmp);
+
        if (ret)
                return ret;
 
        return count;
 }
 
-static void package_appid_release(struct config_item *item)
+static void package_details_release(struct config_item *item)
 {
-       printk(KERN_INFO "sdcardfs: removing %s\n", item->ci_dentry->d_name.name);
-       /* item->ci_name is freed already, so we rely on the dentry */
-       remove_packagelist_entry(item->ci_dentry->d_name.name);
-       kfree(to_package_appid(item));
+       struct package_details *package_details = to_package_details(item);
+       printk(KERN_INFO "sdcardfs: removing %s\n", package_details->name);
+       remove_packagelist_entry(package_details->name);
+       kfree(package_details->name);
+       kfree(package_details);
 }
 
-static struct configfs_item_operations package_appid_item_ops = {
-       .release                = package_appid_release,
-       .show_attribute         = package_appid_attr_show,
-       .store_attribute        = package_appid_attr_store,
+PACKAGE_DETAILS_ATTR(appid, S_IRUGO | S_IWUGO, package_details_appid_show, package_details_appid_store);
+
+static struct configfs_attribute *package_details_attrs[] = {
+       &package_details_attr_appid.attr,
+       NULL,
+};
+
+CONFIGFS_ATTR_OPS(package_details);
+static struct configfs_item_operations package_details_item_ops = {
+       .release = package_details_release,
+       .show_attribute = package_details_attr_show,
+       .store_attribute = package_details_attr_store,
 };
 
 static struct config_item_type package_appid_type = {
-       .ct_item_ops    = &package_appid_item_ops,
-       .ct_attrs       = package_appid_attrs,
+       .ct_item_ops    = &package_details_item_ops,
+       .ct_attrs       = package_details_attrs,
        .ct_owner       = THIS_MODULE,
 };
 
-
-struct sdcardfs_packages {
-       struct config_group group;
+struct packages {
+       struct configfs_subsystem subsystem;
 };
 
-static inline struct sdcardfs_packages *to_sdcardfs_packages(struct config_item *item)
+static inline struct packages *to_packages(struct config_item *item)
 {
-       return item ? container_of(to_config_group(item), struct sdcardfs_packages, group) : NULL;
+       return item ? container_of(to_configfs_subsystem(to_config_group(item)), struct packages, subsystem) : NULL;
 }
 
-static struct config_item *sdcardfs_packages_make_item(struct config_group *group, const char *name)
+CONFIGFS_ATTR_STRUCT(packages);
+#define PACKAGES_ATTR(_name, _mode, _show, _store)     \
+struct packages_attribute packages_attr_##_name = __CONFIGFS_ATTR(_name, _mode, _show, _store)
+#define PACKAGES_ATTR_RO(_name, _show) \
+struct packages_attribute packages_attr_##_name = __CONFIGFS_ATTR_RO(_name, _show);
+
+static struct config_item *packages_make_item(struct config_group *group, const char *name)
 {
-       struct package_appid *package_appid;
+       struct package_details *package_details;
 
-       package_appid = kzalloc(sizeof(struct package_appid), GFP_KERNEL);
-       if (!package_appid)
+       package_details = kzalloc(sizeof(struct package_details), GFP_KERNEL);
+       if (!package_details)
+               return ERR_PTR(-ENOMEM);
+       package_details->name = kstrdup(name, GFP_KERNEL);
+       if (!package_details->name)
                return ERR_PTR(-ENOMEM);
 
-       config_item_init_type_name(&package_appid->item, name,
+       config_item_init_type_name(&package_details->item, name,
                                   &package_appid_type);
 
-       package_appid->add_pid = 0;
-
-       return &package_appid->item;
+       return &package_details->item;
 }
 
-static struct configfs_attribute sdcardfs_packages_attr_description = {
-       .ca_owner = THIS_MODULE,
-       .ca_name = "packages_gid.list",
-       .ca_mode = S_IRUGO,
-};
-
-static struct configfs_attribute *sdcardfs_packages_attrs[] = {
-       &sdcardfs_packages_attr_description,
-       NULL,
-};
-
-static ssize_t packages_attr_show(struct config_item *item,
-                                        struct configfs_attribute *attr,
+static ssize_t packages_list_show(struct packages *packages,
                                         char *page)
 {
        struct hashtable_entry *hash_cur;
@@ -349,38 +342,41 @@ static ssize_t packages_attr_show(struct config_item *item,
        return count;
 }
 
-static void sdcardfs_packages_release(struct config_item *item)
-{
+struct packages_attribute packages_attr_packages_gid_list = __CONFIGFS_ATTR_RO(packages_gid.list, packages_list_show);
 
-       printk(KERN_INFO "sdcardfs: destroyed something?\n");
-       kfree(to_sdcardfs_packages(item));
-}
+static struct configfs_attribute *packages_attrs[] = {
+       &packages_attr_packages_gid_list.attr,
+       NULL,
+};
 
-static struct configfs_item_operations sdcardfs_packages_item_ops = {
-       .release        = sdcardfs_packages_release,
-       .show_attribute = packages_attr_show,
+CONFIGFS_ATTR_OPS(packages)
+static struct configfs_item_operations packages_item_ops = {
+       .show_attribute = packages_attr_show,
+       .store_attribute = packages_attr_store,
 };
 
 /*
  * Note that, since no extra work is required on ->drop_item(),
  * no ->drop_item() is provided.
  */
-static struct configfs_group_operations sdcardfs_packages_group_ops = {
-       .make_item      = sdcardfs_packages_make_item,
+static struct configfs_group_operations packages_group_ops = {
+       .make_item      = packages_make_item,
 };
 
-static struct config_item_type sdcardfs_packages_type = {
-       .ct_item_ops    = &sdcardfs_packages_item_ops,
-       .ct_group_ops   = &sdcardfs_packages_group_ops,
-       .ct_attrs       = sdcardfs_packages_attrs,
+static struct config_item_type packages_type = {
+       .ct_item_ops    = &packages_item_ops,
+       .ct_group_ops   = &packages_group_ops,
+       .ct_attrs       = packages_attrs,
        .ct_owner       = THIS_MODULE,
 };
 
-static struct configfs_subsystem sdcardfs_packages_subsys = {
-       .su_group = {
-               .cg_item = {
-                       .ci_namebuf = "sdcardfs",
-                       .ci_type = &sdcardfs_packages_type,
+static struct packages sdcardfs_packages = {
+       .subsystem = {
+               .su_group = {
+                       .cg_item = {
+                               .ci_namebuf = "sdcardfs",
+                               .ci_type = &packages_type,
+                       },
                },
        },
 };
@@ -388,7 +384,7 @@ static struct configfs_subsystem sdcardfs_packages_subsys = {
 static int configfs_sdcardfs_init(void)
 {
        int ret;
-       struct configfs_subsystem *subsys = &sdcardfs_packages_subsys;
+       struct configfs_subsystem *subsys = &sdcardfs_packages.subsystem;
 
        config_group_init(&subsys->su_group);
        mutex_init(&subsys->su_mutex);
@@ -403,7 +399,7 @@ static int configfs_sdcardfs_init(void)
 
 static void configfs_sdcardfs_exit(void)
 {
-       configfs_unregister_subsystem(&sdcardfs_packages_subsys);
+       configfs_unregister_subsystem(&sdcardfs_packages.subsystem);
 }
 
 int packagelist_init(void)