1 files changed, 271 insertions, 53 deletions

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index c81ce7f200a6..f419519ec41f 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -255,6 +255,12 @@ static void configfs_init_file(struct inode * inode)
 	inode->i_fop = &configfs_file_operations;
 }
 
+static void configfs_init_bin_file(struct inode *inode)
+{
+	inode->i_size = 0;
+	inode->i_fop = &configfs_bin_file_operations;
+}
+
 static void init_symlink(struct inode * inode)
 {
 	inode->i_op = &configfs_symlink_inode_operations;
@@ -423,7 +429,9 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
 	spin_unlock(&configfs_dirent_lock);
 
 	error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG,
-				configfs_init_file);
+				(sd->s_type & CONFIGFS_ITEM_BIN_ATTR) ?
+					configfs_init_bin_file :
+					configfs_init_file);
 	if (error) {
 		configfs_put(sd);
 		return error;
@@ -583,6 +591,7 @@ static int populate_attrs(struct config_item *item)
 {
 	struct config_item_type *t = item->ci_type;
 	struct configfs_attribute *attr;
+	struct configfs_bin_attribute *bin_attr;
 	int error = 0;
 	int i;
 
@@ -594,6 +603,13 @@ static int populate_attrs(struct config_item *item)
 				break;
 		}
 	}
+	if (t->ct_bin_attrs) {
+		for (i = 0; (bin_attr = t->ct_bin_attrs[i]) != NULL; i++) {
+			error = configfs_create_bin_file(item, bin_attr);
+			if (error)
+				break;
+		}
+	}
 
 	if (error)
 		detach_attrs(item);
@@ -624,13 +640,13 @@ static void detach_groups(struct config_group *group)
 
 		child = sd->s_dentry;
 
-		mutex_lock(&d_inode(child)->i_mutex);
+		inode_lock(d_inode(child));
 
 		configfs_detach_group(sd->s_element);
 		d_inode(child)->i_flags |= S_DEAD;
 		dont_mount(child);
 
-		mutex_unlock(&d_inode(child)->i_mutex);
+		inode_unlock(d_inode(child));
 
 		d_delete(child);
 		dput(child);
@@ -818,11 +834,11 @@ static int configfs_attach_item(struct config_item *parent_item,
 			 * the VFS may already have hit and used them. Thus,
 			 * we must lock them as rmdir() would.
 			 */
-			mutex_lock(&d_inode(dentry)->i_mutex);
+			inode_lock(d_inode(dentry));
 			configfs_remove_dir(item);
 			d_inode(dentry)->i_flags |= S_DEAD;
 			dont_mount(dentry);
-			mutex_unlock(&d_inode(dentry)->i_mutex);
+			inode_unlock(d_inode(dentry));
 			d_delete(dentry);
 		}
 	}
@@ -858,7 +874,7 @@ static int configfs_attach_group(struct config_item *parent_item,
 		 * We must also lock the inode to remove it safely in case of
 		 * error, as rmdir() would.
 		 */
-		mutex_lock_nested(&d_inode(dentry)->i_mutex, I_MUTEX_CHILD);
+		inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD);
 		configfs_adjust_dir_dirent_depth_before_populate(sd);
 		ret = populate_groups(to_config_group(item));
 		if (ret) {
@@ -867,7 +883,7 @@ static int configfs_attach_group(struct config_item *parent_item,
 			dont_mount(dentry);
 		}
 		configfs_adjust_dir_dirent_depth_after_populate(sd);
-		mutex_unlock(&d_inode(dentry)->i_mutex);
+		inode_unlock(d_inode(dentry));
 		if (ret)
 			d_delete(dentry);
 	}
@@ -1054,11 +1070,55 @@ out:
 	return ret;
 }
 
+static int configfs_do_depend_item(struct dentry *subsys_dentry,
+				   struct config_item *target)
+{
+	struct configfs_dirent *p;
+	int ret;
+
+	spin_lock(&configfs_dirent_lock);
+	/* Scan the tree, return 0 if found */
+	ret = configfs_depend_prep(subsys_dentry, target);
+	if (ret)
+		goto out_unlock_dirent_lock;
+
+	/*
+	 * We are sure that the item is not about to be removed by rmdir(), and
+	 * not in the middle of attachment by mkdir().
+	 */
+	p = target->ci_dentry->d_fsdata;
+	p->s_dependent_count += 1;
+
+out_unlock_dirent_lock:
+	spin_unlock(&configfs_dirent_lock);
+
+	return ret;
+}
+
+static inline struct configfs_dirent *
+configfs_find_subsys_dentry(struct configfs_dirent *root_sd,
+			    struct config_item *subsys_item)
+{
+	struct configfs_dirent *p;
+	struct configfs_dirent *ret = NULL;
+
+	list_for_each_entry(p, &root_sd->s_children, s_sibling) {
+		if (p->s_type & CONFIGFS_DIR &&
+		    p->s_element == subsys_item) {
+			ret = p;
+			break;
+		}
+	}
+
+	return ret;
+}
+
+
 int configfs_depend_item(struct configfs_subsystem *subsys,
 			 struct config_item *target)
 {
 	int ret;
-	struct configfs_dirent *p, *root_sd, *subsys_sd = NULL;
+	struct configfs_dirent *subsys_sd;
 	struct config_item *s_item = &subsys->su_group.cg_item;
 	struct dentry *root;
 
@@ -1075,43 +1135,19 @@ int configfs_depend_item(struct configfs_subsystem *subsys,
 	 * subsystem is really registered, and so we need to lock out
 	 * configfs_[un]register_subsystem().
 	 */
-	mutex_lock(&d_inode(root)->i_mutex);
-
-	root_sd = root->d_fsdata;
-
-	list_for_each_entry(p, &root_sd->s_children, s_sibling) {
-		if (p->s_type & CONFIGFS_DIR) {
-			if (p->s_element == s_item) {
-				subsys_sd = p;
-				break;
-			}
-		}
-	}
+	inode_lock(d_inode(root));
 
+	subsys_sd = configfs_find_subsys_dentry(root->d_fsdata, s_item);
 	if (!subsys_sd) {
 		ret = -ENOENT;
 		goto out_unlock_fs;
 	}
 
 	/* Ok, now we can trust subsys/s_item */
+	ret = configfs_do_depend_item(subsys_sd->s_dentry, target);
 
-	spin_lock(&configfs_dirent_lock);
-	/* Scan the tree, return 0 if found */
-	ret = configfs_depend_prep(subsys_sd->s_dentry, target);
-	if (ret)
-		goto out_unlock_dirent_lock;
-
-	/*
-	 * We are sure that the item is not about to be removed by rmdir(), and
-	 * not in the middle of attachment by mkdir().
-	 */
-	p = target->ci_dentry->d_fsdata;
-	p->s_dependent_count += 1;
-
-out_unlock_dirent_lock:
-	spin_unlock(&configfs_dirent_lock);
 out_unlock_fs:
-	mutex_unlock(&d_inode(root)->i_mutex);
+	inode_unlock(d_inode(root));
 
 	/*
 	 * If we succeeded, the fs is pinned via other methods.  If not,
@@ -1128,8 +1164,7 @@ EXPORT_SYMBOL(configfs_depend_item);
  * configfs_depend_item() because we know that that the client driver is
  * pinned, thus the subsystem is pinned, and therefore configfs is pinned.
  */
-void configfs_undepend_item(struct configfs_subsystem *subsys,
-			    struct config_item *target)
+void configfs_undepend_item(struct config_item *target)
 {
 	struct configfs_dirent *sd;
 
@@ -1152,6 +1187,79 @@ void configfs_undepend_item(struct configfs_subsystem *subsys,
 }
 EXPORT_SYMBOL(configfs_undepend_item);
 
+/*
+ * caller_subsys is a caller's subsystem not target's. This is used to
+ * determine if we should lock root and check subsys or not. When we are
+ * in the same subsystem as our target there is no need to do locking as
+ * we know that subsys is valid and is not unregistered during this function
+ * as we are called from callback of one of his children and VFS holds a lock
+ * on some inode. Otherwise we have to lock our root to  ensure that target's
+ * subsystem it is not unregistered during this function.
+ */
+int configfs_depend_item_unlocked(struct configfs_subsystem *caller_subsys,
+				  struct config_item *target)
+{
+	struct configfs_subsystem *target_subsys;
+	struct config_group *root, *parent;
+	struct configfs_dirent *subsys_sd;
+	int ret = -ENOENT;
+
+	/* Disallow this function for configfs root */
+	if (configfs_is_root(target))
+		return -EINVAL;
+
+	parent = target->ci_group;
+	/*
+	 * This may happen when someone is trying to depend root
+	 * directory of some subsystem
+	 */
+	if (configfs_is_root(&parent->cg_item)) {
+		target_subsys = to_configfs_subsystem(to_config_group(target));
+		root = parent;
+	} else {
+		target_subsys = parent->cg_subsys;
+		/* Find a cofnigfs root as we may need it for locking */
+		for (root = parent; !configfs_is_root(&root->cg_item);
+		     root = root->cg_item.ci_group)
+			;
+	}
+
+	if (target_subsys != caller_subsys) {
+		/*
+		 * We are in other configfs subsystem, so we have to do
+		 * additional locking to prevent other subsystem from being
+		 * unregistered
+		 */
+		inode_lock(d_inode(root->cg_item.ci_dentry));
+
+		/*
+		 * As we are trying to depend item from other subsystem
+		 * we have to check if this subsystem is still registered
+		 */
+		subsys_sd = configfs_find_subsys_dentry(
+				root->cg_item.ci_dentry->d_fsdata,
+				&target_subsys->su_group.cg_item);
+		if (!subsys_sd)
+			goto out_root_unlock;
+	} else {
+		subsys_sd = target_subsys->su_group.cg_item.ci_dentry->d_fsdata;
+	}
+
+	/* Now we can execute core of depend item */
+	ret = configfs_do_depend_item(subsys_sd->s_dentry, target);
+
+	if (target_subsys != caller_subsys)
+out_root_unlock:
+		/*
+		 * We were called from subsystem other than our target so we
+		 * took some locks so now it's time to release them
+		 */
+		inode_unlock(d_inode(root->cg_item.ci_dentry));
+
+	return ret;
+}
+EXPORT_SYMBOL(configfs_depend_item_unlocked);
+
 static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
 	int ret = 0;
@@ -1453,7 +1561,7 @@ int configfs_rename_dir(struct config_item * item, const char *new_name)
 	down_write(&configfs_rename_sem);
 	parent = item->parent->dentry;
 
-	mutex_lock(&d_inode(parent)->i_mutex);
+	inode_lock(d_inode(parent));
 
 	new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
 	if (!IS_ERR(new_dentry)) {
@@ -1469,7 +1577,7 @@ int configfs_rename_dir(struct config_item * item, const char *new_name)
 			error = -EEXIST;
 		dput(new_dentry);
 	}
-	mutex_unlock(&d_inode(parent)->i_mutex);
+	inode_unlock(d_inode(parent));
 	up_write(&configfs_rename_sem);
 
 	return error;
@@ -1482,7 +1590,7 @@ static int configfs_dir_open(struct inode *inode, struct file *file)
 	struct configfs_dirent * parent_sd = dentry->d_fsdata;
 	int err;
 
-	mutex_lock(&d_inode(dentry)->i_mutex);
+	inode_lock(d_inode(dentry));
 	/*
 	 * Fake invisibility if dir belongs to a group/default groups hierarchy
 	 * being attached
@@ -1495,7 +1603,7 @@ static int configfs_dir_open(struct inode *inode, struct file *file)
 		else
 			err = 0;
 	}
-	mutex_unlock(&d_inode(dentry)->i_mutex);
+	inode_unlock(d_inode(dentry));
 
 	return err;
 }
@@ -1505,11 +1613,11 @@ static int configfs_dir_close(struct inode *inode, struct file *file)
 	struct dentry * dentry = file->f_path.dentry;
 	struct configfs_dirent * cursor = file->private_data;
 
-	mutex_lock(&d_inode(dentry)->i_mutex);
+	inode_lock(d_inode(dentry));
 	spin_lock(&configfs_dirent_lock);
 	list_del_init(&cursor->s_sibling);
 	spin_unlock(&configfs_dirent_lock);
-	mutex_unlock(&d_inode(dentry)->i_mutex);
+	inode_unlock(d_inode(dentry));
 
 	release_configfs_dirent(cursor);
 
@@ -1590,7 +1698,7 @@ static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence)
 {
 	struct dentry * dentry = file->f_path.dentry;
 
-	mutex_lock(&d_inode(dentry)->i_mutex);
+	inode_lock(d_inode(dentry));
 	switch (whence) {
 		case 1:
 			offset += file->f_pos;
@@ -1598,7 +1706,7 @@ static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence)
 			if (offset >= 0)
 				break;
 		default:
-			mutex_unlock(&d_inode(dentry)->i_mutex);
+			inode_unlock(d_inode(dentry));
 			return -EINVAL;
 	}
 	if (offset != file->f_pos) {
@@ -1624,7 +1732,7 @@ static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence)
 			spin_unlock(&configfs_dirent_lock);
 		}
 	}
-	mutex_unlock(&d_inode(dentry)->i_mutex);
+	inode_unlock(d_inode(dentry));
 	return offset;
 }
 
@@ -1636,6 +1744,116 @@ const struct file_operations configfs_dir_operations = {
 	.iterate	= configfs_readdir,
 };
 
+/**
+ * configfs_register_group - creates a parent-child relation between two groups
+ * @parent_group:	parent group
+ * @group:		child group
+ *
+ * link groups, creates dentry for the child and attaches it to the
+ * parent dentry.
+ *
+ * Return: 0 on success, negative errno code on error
+ */
+int configfs_register_group(struct config_group *parent_group,
+			    struct config_group *group)
+{
+	struct configfs_subsystem *subsys = parent_group->cg_subsys;
+	struct dentry *parent;
+	int ret;
+
+	mutex_lock(&subsys->su_mutex);
+	link_group(parent_group, group);
+	mutex_unlock(&subsys->su_mutex);
+
+	parent = parent_group->cg_item.ci_dentry;
+
+	inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
+	ret = create_default_group(parent_group, group);
+	if (!ret) {
+		spin_lock(&configfs_dirent_lock);
+		configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata);
+		spin_unlock(&configfs_dirent_lock);
+	}
+	inode_unlock(d_inode(parent));
+	return ret;
+}
+EXPORT_SYMBOL(configfs_register_group);
+
+/**
+ * configfs_unregister_group() - unregisters a child group from its parent
+ * @group: parent group to be unregistered
+ *
+ * Undoes configfs_register_group()
+ */
+void configfs_unregister_group(struct config_group *group)
+{
+	struct configfs_subsystem *subsys = group->cg_subsys;
+	struct dentry *dentry = group->cg_item.ci_dentry;
+	struct dentry *parent = group->cg_item.ci_parent->ci_dentry;
+
+	inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
+	spin_lock(&configfs_dirent_lock);
+	configfs_detach_prep(dentry, NULL);
+	spin_unlock(&configfs_dirent_lock);
+
+	configfs_detach_group(&group->cg_item);
+	d_inode(dentry)->i_flags |= S_DEAD;
+	dont_mount(dentry);
+	d_delete(dentry);
+	inode_unlock(d_inode(parent));
+
+	dput(dentry);
+
+	mutex_lock(&subsys->su_mutex);
+	unlink_group(group);
+	mutex_unlock(&subsys->su_mutex);
+}
+EXPORT_SYMBOL(configfs_unregister_group);
+
+/**
+ * configfs_register_default_group() - allocates and registers a child group
+ * @parent_group:	parent group
+ * @name:		child group name
+ * @item_type:		child item type description
+ *
+ * boilerplate to allocate and register a child group with its parent. We need
+ * kzalloc'ed memory because child's default_group is initially empty.
+ *
+ * Return: allocated config group or ERR_PTR() on error
+ */
+struct config_group *
+configfs_register_default_group(struct config_group *parent_group,
+				const char *name,
+				struct config_item_type *item_type)
+{
+	int ret;
+	struct config_group *group;
+
+	group = kzalloc(sizeof(*group), GFP_KERNEL);
+	if (!group)
+		return ERR_PTR(-ENOMEM);
+	config_group_init_type_name(group, name, item_type);
+
+	ret = configfs_register_group(parent_group, group);
+	if (ret) {
+		kfree(group);
+		return ERR_PTR(ret);
+	}
+	return group;
+}
+EXPORT_SYMBOL(configfs_register_default_group);
+
+/**
+ * configfs_unregister_default_group() - unregisters and frees a child group
+ * @group:	the group to act on
+ */
+void configfs_unregister_default_group(struct config_group *group)
+{
+	configfs_unregister_group(group);
+	kfree(group);
+}
+EXPORT_SYMBOL(configfs_unregister_default_group);
+
 int configfs_register_subsystem(struct configfs_subsystem *subsys)
 {
 	int err;
@@ -1654,7 +1872,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
 	sd = root->d_fsdata;
 	link_group(to_config_group(sd->s_element), group);
 
-	mutex_lock_nested(&d_inode(root)->i_mutex, I_MUTEX_PARENT);
+	inode_lock_nested(d_inode(root), I_MUTEX_PARENT);
 
 	err = -ENOMEM;
 	dentry = d_alloc_name(root, group->cg_item.ci_name);
@@ -1674,7 +1892,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
 		}
 	}
 
-	mutex_unlock(&d_inode(root)->i_mutex);
+	inode_unlock(d_inode(root));
 
 	if (err) {
 		unlink_group(group);
@@ -1695,9 +1913,9 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
 		return;
 	}
 
-	mutex_lock_nested(&d_inode(root)->i_mutex,
+	inode_lock_nested(d_inode(root),
 			  I_MUTEX_PARENT);
-	mutex_lock_nested(&d_inode(dentry)->i_mutex, I_MUTEX_CHILD);
+	inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD);
 	mutex_lock(&configfs_symlink_mutex);
 	spin_lock(&configfs_dirent_lock);
 	if (configfs_detach_prep(dentry, NULL)) {
@@ -1708,11 +1926,11 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
 	configfs_detach_group(&group->cg_item);
 	d_inode(dentry)->i_flags |= S_DEAD;
 	dont_mount(dentry);
-	mutex_unlock(&d_inode(dentry)->i_mutex);
+	inode_unlock(d_inode(dentry));
 
 	d_delete(dentry);
 
-	mutex_unlock(&d_inode(root)->i_mutex);
+	inode_unlock(d_inode(root));
 
 	dput(dentry);