/* * fs/sysfs/group.c - Operations for adding/removing multiple files at once. * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Open Source Development Lab * * This file is released undert the GPL v2. * */ #include <linux/kobject.h> #include <linux/module.h> #include <linux/dcache.h> #include <linux/namei.h> #include <linux/err.h> #include "sysfs.h" static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj, const struct attribute_group *grp) { struct attribute *const* attr; int i; for (i = 0, attr = grp->attrs; *attr; i++, attr++) sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name); } static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj, const struct attribute_group *grp, int update) { struct attribute *const* attr; int error = 0, i; for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) { umode_t mode = 0; /* in update mode, we're changing the permissions or * visibility. Do this by first removing then * re-adding (if required) the file */ if (update) sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name); if (grp->is_visible) { mode = grp->is_visible(kobj, *attr, i); if (!mode) continue; } error = sysfs_add_file_mode(dir_sd, *attr, SYSFS_KOBJ_ATTR, (*attr)->mode | mode); if (unlikely(error)) break; } if (error) remove_files(dir_sd, kobj, grp); return error; } static int internal_create_group(struct kobject *kobj, int update, const struct attribute_group *grp) { struct sysfs_dirent *sd; int error; BUG_ON(!kobj || (!update && !kobj->sd)); /* Updates may happen before the object has been instantiated */ if (unlikely(update && !kobj->sd)) return -EINVAL; if (!grp->attrs) { WARN(1, "sysfs: attrs not set by subsystem for group: %s/%s\n", kobj->name, grp->name ? "" : grp->name); return -EINVAL; } if (grp->name) { error = sysfs_create_subdir(kobj, grp->name, &sd); if (error) return error; } else sd = kobj->sd; sysfs_get(sd); error = create_files(sd, kobj, grp, update); if (error) { if (grp->name) sysfs_remove_subdir(sd); } sysfs_put(sd); return error; } /** * sysfs_create_group - given a directory kobject, create an attribute group * @kobj: The kobject to create the group on * @grp: The attribute group to create * * This function creates a group for the first time. It will explicitly * warn and error if any of the attribute files being created already exist. * * Returns 0 on success or error. */ int sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) { return internal_create_group(kobj, 0, grp); } /** * sysfs_update_group - given a directory kobject, update an attribute group * @kobj: The kobject to update the group on * @grp: The attribute group to update * * This function updates an attribute group. Unlike * sysfs_create_group(), it will explicitly not warn or error if any * of the attribute files being created already exist. Furthermore, * if the visibility of the files has changed through the is_visible() * callback, it will update the permissions and add or remove the * relevant files. * * The primary use for this function is to call it after making a change * that affects group visibility. * * Returns 0 on success or error. */ int sysfs_update_group(struct kobject *kobj, const struct attribute_group *grp) { return internal_create_group(kobj, 1, grp); } void sysfs_remove_group(struct kobject * kobj, const struct attribute_group * grp) { struct sysfs_dirent *dir_sd = kobj->sd; struct sysfs_dirent *sd; if (grp->name) { sd = sysfs_get_dirent(dir_sd, NULL, grp->name); if (!sd) { WARN(!sd, KERN_WARNING "sysfs group %p not found for " "kobject '%s'\n", grp, kobject_name(kobj)); return; } } else sd = sysfs_get(dir_sd); remove_files(sd, kobj, grp); if (grp->name) sysfs_remove_subdir(sd); sysfs_put(sd); } /** * sysfs_merge_group - merge files into a pre-existing attribute group. * @kobj: The kobject containing the group. * @grp: The files to create and the attribute group they belong to. * * This function returns an error if the group doesn't exist or any of the * files already exist in that group, in which case none of the new files * are created. */ int sysfs_merge_group(struct kobject *kobj, const struct attribute_group *grp) { struct sysfs_dirent *dir_sd; int error = 0; struct attribute *const *attr; int i; dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name); if (!dir_sd) return -ENOENT; for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr)) error = sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR); if (error) { while (--i >= 0) sysfs_hash_and_remove(dir_sd, NULL, (*--attr)->name); } sysfs_put(dir_sd); return error; } EXPORT_SYMBOL_GPL(sysfs_merge_group); /** * sysfs_unmerge_group - remove files from a pre-existing attribute group. * @kobj: The kobject containing the group. * @grp: The files to remove and the attribute group they belong to. */ void sysfs_unmerge_group(struct kobject *kobj, const struct attribute_group *grp) { struct sysfs_dirent *dir_sd; struct attribute *const *attr; dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name); if (dir_sd) { for (attr = grp->attrs; *attr; ++attr) sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name); sysfs_put(dir_sd); } } EXPORT_SYMBOL_GPL(sysfs_unmerge_group); EXPORT_SYMBOL_GPL(sysfs_create_group); EXPORT_SYMBOL_GPL(sysfs_update_group); EXPORT_SYMBOL_GPL(sysfs_remove_group);