| /* |
| * fs/sysfs/group.c - Operations for adding/removing multiple files at once. |
| * |
| * Copyright (c) 2003 Patrick Mochel |
| * Copyright (c) 2003 Open Source Development Lab |
| * Copyright (c) 2013 Greg Kroah-Hartman |
| * Copyright (c) 2013 The Linux Foundation |
| * |
| * 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 kernfs_node *parent, |
| const struct attribute_group *grp) |
| { |
| struct attribute *const *attr; |
| struct bin_attribute *const *bin_attr; |
| |
| if (grp->attrs) |
| for (attr = grp->attrs; *attr; attr++) |
| kernfs_remove_by_name(parent, (*attr)->name); |
| if (grp->bin_attrs) |
| for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) |
| kernfs_remove_by_name(parent, (*bin_attr)->attr.name); |
| } |
| |
| static int create_files(struct kernfs_node *parent, struct kobject *kobj, |
| const struct attribute_group *grp, int update) |
| { |
| struct attribute *const *attr; |
| struct bin_attribute *const *bin_attr; |
| int error = 0, i; |
| |
| if (grp->attrs) { |
| for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) { |
| umode_t mode = (*attr)->mode; |
| |
| /* |
| * In update mode, we're changing the permissions or |
| * visibility. Do this by first removing then |
| * re-adding (if required) the file. |
| */ |
| if (update) |
| kernfs_remove_by_name(parent, (*attr)->name); |
| if (grp->is_visible) { |
| mode = grp->is_visible(kobj, *attr, i); |
| if (!mode) |
| continue; |
| } |
| |
| WARN(mode & ~(SYSFS_PREALLOC | 0664), |
| "Attribute %s: Invalid permissions 0%o\n", |
| (*attr)->name, mode); |
| |
| mode &= SYSFS_PREALLOC | 0664; |
| error = sysfs_add_file_mode_ns(parent, *attr, false, |
| mode, NULL); |
| if (unlikely(error)) |
| break; |
| } |
| if (error) { |
| remove_files(parent, grp); |
| goto exit; |
| } |
| } |
| |
| if (grp->bin_attrs) { |
| for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) { |
| if (update) |
| 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; |
| } |
| if (error) |
| remove_files(parent, grp); |
| } |
| exit: |
| return error; |
| } |
| |
| |
| static int internal_create_group(struct kobject *kobj, int update, |
| const struct attribute_group *grp) |
| { |
| struct kernfs_node *kn; |
| 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 && !grp->bin_attrs) { |
| WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n", |
| kobj->name, grp->name ?: ""); |
| return -EINVAL; |
| } |
| if (grp->name) { |
| kn = kernfs_create_dir(kobj->sd, grp->name, |
| S_IRWXU | S_IRUGO | S_IXUGO, kobj); |
| if (IS_ERR(kn)) { |
| if (PTR_ERR(kn) == -EEXIST) |
| sysfs_warn_dup(kobj->sd, grp->name); |
| return PTR_ERR(kn); |
| } |
| } else |
| kn = kobj->sd; |
| kernfs_get(kn); |
| error = create_files(kn, kobj, grp, update); |
| if (error) { |
| if (grp->name) |
| kernfs_remove(kn); |
| } |
| kernfs_put(kn); |
| 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 code on failure. |
| */ |
| int sysfs_create_group(struct kobject *kobj, |
| const struct attribute_group *grp) |
| { |
| return internal_create_group(kobj, 0, grp); |
| } |
| EXPORT_SYMBOL_GPL(sysfs_create_group); |
| |
| /** |
| * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups |
| * @kobj: The kobject to create the group on |
| * @groups: The attribute groups to create, NULL terminated |
| * |
| * This function creates a bunch of attribute groups. If an error occurs when |
| * creating a group, all previously created groups will be removed, unwinding |
| * everything back to the original state when this function was called. |
| * It will explicitly warn and error if any of the attribute files being |
| * created already exist. |
| * |
| * Returns 0 on success or error code from sysfs_create_group on failure. |
| */ |
| int sysfs_create_groups(struct kobject *kobj, |
| const struct attribute_group **groups) |
| { |
| int error = 0; |
| int i; |
| |
| if (!groups) |
| return 0; |
| |
| for (i = 0; groups[i]; i++) { |
| error = sysfs_create_group(kobj, groups[i]); |
| if (error) { |
| while (--i >= 0) |
| sysfs_remove_group(kobj, groups[i]); |
| break; |
| } |
| } |
| return error; |
| } |
| EXPORT_SYMBOL_GPL(sysfs_create_groups); |
| |
| /** |
| * 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 code on failure. |
| */ |
| int sysfs_update_group(struct kobject *kobj, |
| const struct attribute_group *grp) |
| { |
| return internal_create_group(kobj, 1, grp); |
| } |
| EXPORT_SYMBOL_GPL(sysfs_update_group); |
| |
| /** |
| * sysfs_remove_group: remove a group from a kobject |
| * @kobj: kobject to remove the group from |
| * @grp: group to remove |
| * |
| * This function removes a group of attributes from a kobject. The attributes |
| * previously have to have been created for this group, otherwise it will fail. |
| */ |
| void sysfs_remove_group(struct kobject *kobj, |
| const struct attribute_group *grp) |
| { |
| struct kernfs_node *parent = kobj->sd; |
| struct kernfs_node *kn; |
| |
| if (grp->name) { |
| kn = kernfs_find_and_get(parent, grp->name); |
| if (!kn) { |
| WARN(!kn, KERN_WARNING |
| "sysfs group %p not found for kobject '%s'\n", |
| grp, kobject_name(kobj)); |
| return; |
| } |
| } else { |
| kn = parent; |
| kernfs_get(kn); |
| } |
| |
| remove_files(kn, grp); |
| if (grp->name) |
| kernfs_remove(kn); |
| |
| kernfs_put(kn); |
| } |
| EXPORT_SYMBOL_GPL(sysfs_remove_group); |
| |
| /** |
| * sysfs_remove_groups - remove a list of groups |
| * |
| * @kobj: The kobject for the groups to be removed from |
| * @groups: NULL terminated list of groups to be removed |
| * |
| * If groups is not NULL, remove the specified groups from the kobject. |
| */ |
| void sysfs_remove_groups(struct kobject *kobj, |
| const struct attribute_group **groups) |
| { |
| int i; |
| |
| if (!groups) |
| return; |
| for (i = 0; groups[i]; i++) |
| sysfs_remove_group(kobj, groups[i]); |
| } |
| EXPORT_SYMBOL_GPL(sysfs_remove_groups); |
| |
| /** |
| * 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 kernfs_node *parent; |
| int error = 0; |
| struct attribute *const *attr; |
| int i; |
| |
| parent = kernfs_find_and_get(kobj->sd, grp->name); |
| if (!parent) |
| return -ENOENT; |
| |
| for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr)) |
| error = sysfs_add_file(parent, *attr, false); |
| if (error) { |
| while (--i >= 0) |
| kernfs_remove_by_name(parent, (*--attr)->name); |
| } |
| kernfs_put(parent); |
| |
| 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 kernfs_node *parent; |
| struct attribute *const *attr; |
| |
| parent = kernfs_find_and_get(kobj->sd, grp->name); |
| if (parent) { |
| for (attr = grp->attrs; *attr; ++attr) |
| kernfs_remove_by_name(parent, (*attr)->name); |
| kernfs_put(parent); |
| } |
| } |
| EXPORT_SYMBOL_GPL(sysfs_unmerge_group); |
| |
| /** |
| * sysfs_add_link_to_group - add a symlink to an attribute group. |
| * @kobj: The kobject containing the group. |
| * @group_name: The name of the group. |
| * @target: The target kobject of the symlink to create. |
| * @link_name: The name of the symlink to create. |
| */ |
| int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name, |
| struct kobject *target, const char *link_name) |
| { |
| struct kernfs_node *parent; |
| int error = 0; |
| |
| parent = kernfs_find_and_get(kobj->sd, group_name); |
| if (!parent) |
| return -ENOENT; |
| |
| error = sysfs_create_link_sd(parent, target, link_name); |
| kernfs_put(parent); |
| |
| return error; |
| } |
| EXPORT_SYMBOL_GPL(sysfs_add_link_to_group); |
| |
| /** |
| * sysfs_remove_link_from_group - remove a symlink from an attribute group. |
| * @kobj: The kobject containing the group. |
| * @group_name: The name of the group. |
| * @link_name: The name of the symlink to remove. |
| */ |
| void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, |
| const char *link_name) |
| { |
| struct kernfs_node *parent; |
| |
| parent = kernfs_find_and_get(kobj->sd, group_name); |
| if (parent) { |
| kernfs_remove_by_name(parent, link_name); |
| kernfs_put(parent); |
| } |
| } |
| EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group); |
| |
| /** |
| * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing |
| * to a group or an attribute |
| * @kobj: The kobject containing the group. |
| * @target_kobj: The target kobject. |
| * @target_name: The name of the target group or attribute. |
| */ |
| int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, |
| struct kobject *target_kobj, |
| const char *target_name) |
| { |
| struct kernfs_node *target; |
| struct kernfs_node *entry; |
| struct kernfs_node *link; |
| |
| /* |
| * We don't own @target_kobj and it may be removed at any time. |
| * Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir() |
| * for details. |
| */ |
| spin_lock(&sysfs_symlink_target_lock); |
| target = target_kobj->sd; |
| if (target) |
| kernfs_get(target); |
| spin_unlock(&sysfs_symlink_target_lock); |
| if (!target) |
| return -ENOENT; |
| |
| entry = kernfs_find_and_get(target_kobj->sd, target_name); |
| if (!entry) { |
| kernfs_put(target); |
| return -ENOENT; |
| } |
| |
| link = kernfs_create_link(kobj->sd, target_name, entry); |
| if (IS_ERR(link) && PTR_ERR(link) == -EEXIST) |
| sysfs_warn_dup(kobj->sd, target_name); |
| |
| kernfs_put(entry); |
| kernfs_put(target); |
| return IS_ERR(link) ? PTR_ERR(link) : 0; |
| } |
| EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj); |