5 files changed, 43 insertions, 126 deletions

diff --git a/fs/sysfs/Kconfig b/fs/sysfs/Kconfig
index 8c41feacbac5..b2756014508c 100644
--- a/fs/sysfs/Kconfig
+++ b/fs/sysfs/Kconfig
@@ -1,6 +1,7 @@
 config SYSFS
         bool "sysfs file system support" if EXPERT
         default y
+        select KERNFS
         help
         The sysfs filesystem is a virtual filesystem that the kernel uses to
         export internal kernel objects, their attributes, and their
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index ee0d761c3179..0b45ff42f374 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -19,39 +19,18 @@
 
 DEFINE_SPINLOCK(sysfs_symlink_target_lock);
 
-/**
- *      sysfs_pathname - return full path to sysfs dirent
- *      @kn: kernfs_node whose path we want
- *      @path: caller allocated buffer of size PATH_MAX
- *
- *      Gives the name "/" to the sysfs_root entry; any path returned
- *      is relative to wherever sysfs is mounted.
- */
-static char *sysfs_pathname(struct kernfs_node *kn, char *path)
-{
-        if (kn->parent) {
-                sysfs_pathname(kn->parent, path);
-                strlcat(path, "/", PATH_MAX);
-        }
-        strlcat(path, kn->name, PATH_MAX);
-        return path;
-}
-
 void sysfs_warn_dup(struct kernfs_node *parent, const char *name)
 {
-        char *path;
+        char *buf, *path = NULL;
 
-        path = kzalloc(PATH_MAX, GFP_KERNEL);
-        if (path) {
-                sysfs_pathname(parent, path);
-                strlcat(path, "/", PATH_MAX);
-                strlcat(path, name, PATH_MAX);
-        }
+        buf = kzalloc(PATH_MAX, GFP_KERNEL);
+        if (buf)
+                path = kernfs_path(parent, buf, PATH_MAX);
 
-        WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s'\n",
-             path ? path : name);
+        WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s/%s'\n",
+             path, name);
 
-        kfree(path);
+        kfree(buf);
 }
 
 /**
@@ -122,9 +101,13 @@ void sysfs_remove_dir(struct kobject *kobj)
 int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
                         const void *new_ns)
 {
-        struct kernfs_node *parent = kobj->sd->parent;
+        struct kernfs_node *parent;
+        int ret;
 
-        return kernfs_rename_ns(kobj->sd, parent, new_name, new_ns);
+        parent = kernfs_get_parent(kobj->sd);
+        ret = kernfs_rename_ns(kobj->sd, parent, new_name, new_ns);
+        kernfs_put(parent);
+        return ret;
 }
 
 int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj,
@@ -133,7 +116,6 @@ int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj,
         struct kernfs_node *kn = kobj->sd;
         struct kernfs_node *new_parent;
 
-        BUG_ON(!kn->parent);
         new_parent = new_parent_kobj && new_parent_kobj->sd ?
                 new_parent_kobj->sd : sysfs_root_kn;
 
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 810cf6e613e5..28cc1acd5439 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -372,6 +372,29 @@ void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
 }
 EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
 
+/**
+ * sysfs_remove_file_self - remove an object attribute from its own method
+ * @kobj: object we're acting for
+ * @attr: attribute descriptor
+ *
+ * See kernfs_remove_self() for details.
+ */
+bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr)
+{
+        struct kernfs_node *parent = kobj->sd;
+        struct kernfs_node *kn;
+        bool ret;
+
+        kn = kernfs_find_and_get(parent, attr->name);
+        if (WARN_ON_ONCE(!kn))
+                return false;
+
+        ret = kernfs_remove_self(kn);
+
+        kernfs_put(kn);
+        return ret;
+}
+
 void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr)
 {
         int i;
@@ -430,95 +453,3 @@ void sysfs_remove_bin_file(struct kobject *kobj,
         kernfs_remove_by_name(kobj->sd, attr->attr.name);
 }
 EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
-
-struct sysfs_schedule_callback_struct {
-        struct list_head        workq_list;
-        struct kobject          *kobj;
-        void                    (*func)(void *);
-        void                    *data;
-        struct module           *owner;
-        struct work_struct      work;
-};
-
-static struct workqueue_struct *sysfs_workqueue;
-static DEFINE_MUTEX(sysfs_workq_mutex);
-static LIST_HEAD(sysfs_workq);
-static void sysfs_schedule_callback_work(struct work_struct *work)
-{
-        struct sysfs_schedule_callback_struct *ss = container_of(work,
-                        struct sysfs_schedule_callback_struct, work);
-
-        (ss->func)(ss->data);
-        kobject_put(ss->kobj);
-        module_put(ss->owner);
-        mutex_lock(&sysfs_workq_mutex);
-        list_del(&ss->workq_list);
-        mutex_unlock(&sysfs_workq_mutex);
-        kfree(ss);
-}
-
-/**
- * sysfs_schedule_callback - helper to schedule a callback for a kobject
- * @kobj: object we're acting for.
- * @func: callback function to invoke later.
- * @data: argument to pass to @func.
- * @owner: module owning the callback code
- *
- * sysfs attribute methods must not unregister themselves or their parent
- * kobject (which would amount to the same thing).  Attempts to do so will
- * deadlock, since unregistration is mutually exclusive with driver
- * callbacks.
- *
- * Instead methods can call this routine, which will attempt to allocate
- * and schedule a workqueue request to call back @func with @data as its
- * argument in the workqueue's process context.  @kobj will be pinned
- * until @func returns.
- *
- * Returns 0 if the request was submitted, -ENOMEM if storage could not
- * be allocated, -ENODEV if a reference to @owner isn't available,
- * -EAGAIN if a callback has already been scheduled for @kobj.
- */
-int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
-                void *data, struct module *owner)
-{
-        struct sysfs_schedule_callback_struct *ss, *tmp;
-
-        if (!try_module_get(owner))
-                return -ENODEV;
-
-        mutex_lock(&sysfs_workq_mutex);
-        list_for_each_entry_safe(ss, tmp, &sysfs_workq, workq_list)
-                if (ss->kobj == kobj) {
-                        module_put(owner);
-                        mutex_unlock(&sysfs_workq_mutex);
-                        return -EAGAIN;
-                }
-        mutex_unlock(&sysfs_workq_mutex);
-
-        if (sysfs_workqueue == NULL) {
-                sysfs_workqueue = create_singlethread_workqueue("sysfsd");
-                if (sysfs_workqueue == NULL) {
-                        module_put(owner);
-                        return -ENOMEM;
-                }
-        }
-
-        ss = kmalloc(sizeof(*ss), GFP_KERNEL);
-        if (!ss) {
-                module_put(owner);
-                return -ENOMEM;
-        }
-        kobject_get(kobj);
-        ss->kobj = kobj;
-        ss->func = func;
-        ss->data = data;
-        ss->owner = owner;
-        INIT_WORK(&ss->work, sysfs_schedule_callback_work);
-        INIT_LIST_HEAD(&ss->workq_list);
-        mutex_lock(&sysfs_workq_mutex);
-        list_add_tail(&ss->workq_list, &sysfs_workq);
-        mutex_unlock(&sysfs_workq_mutex);
-        queue_work(sysfs_workqueue, &ss->work);
-        return 0;
-}
-EXPORT_SYMBOL_GPL(sysfs_schedule_callback);
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index 6b579387c67a..aa0406895b53 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -70,8 +70,11 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
         if (grp->bin_attrs) {
                 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
                         if (update)
-                                sysfs_remove_bin_file(kobj, *bin_attr);
-                        error = sysfs_create_bin_file(kobj, *bin_attr);
+                                kernfs_remove_by_name(parent,
+                                                (*bin_attr)->attr.name);
+                        error = sysfs_add_file_mode_ns(parent,
+                                        &(*bin_attr)->attr, true,
+                                        (*bin_attr)->attr.mode, NULL);
                         if (error)
                                 break;
                 }
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 3eaf5c6622eb..a66ad6196f59 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -63,7 +63,7 @@ int __init sysfs_init(void)
 {
         int err;
 
-        sysfs_root = kernfs_create_root(NULL, NULL);
+        sysfs_root = kernfs_create_root(NULL, 0, NULL);
         if (IS_ERR(sysfs_root))
                 return PTR_ERR(sysfs_root);