// SPDX-License-Identifier: GPL-2.0/* * 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 */ #include <linux/kobject.h>#include <linux/module.h>#include <linux/dcache.h>#include <linux/namei.h>#include <linux/err.h>#include <linux/fs.h>#include "sysfs.h" static void remove_files(struct kernfs_node *parent, const struct attribute_group *grp){ struct attribute *const *attr; const 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 umode_t __first_visible(const struct attribute_group *grp, struct kobject *kobj){ if (grp->attrs && grp->attrs[0] && grp->is_visible) return grp->is_visible(kobj, grp->attrs[0], 0); if (grp->attrs && grp->attrs[0] && grp->is_visible_const) return grp->is_visible_const(kobj, grp->attrs[0], 0); if (grp->bin_attrs && grp->bin_attrs[0] && grp->is_bin_visible) return grp->is_bin_visible(kobj, grp->bin_attrs[0], 0); return 0;} static int create_files(struct kernfs_node *parent, struct kobject *kobj, kuid_t uid, kgid_t gid, const struct attribute_group *grp, int update){ struct attribute *const *attr; const 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 || grp->is_visible_const) { if (grp->is_visible) mode = grp->is_visible(kobj, *attr, i); else mode = grp->is_visible_const(kobj, *attr, i); mode &= ~SYSFS_GROUP_INVISIBLE; 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, mode, uid, gid, NULL); if (unlikely(error)) break; } if (error) { remove_files(parent, grp); goto exit; } } if (grp->bin_attrs) { for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) { umode_t mode = (*bin_attr)->attr.mode; size_t size = (*bin_attr)->size; if (update) kernfs_remove_by_name(parent, (*bin_attr)->attr.name); if (grp->is_bin_visible) { mode = grp->is_bin_visible(kobj, *bin_attr, i); mode &= ~SYSFS_GROUP_INVISIBLE; if (!mode) continue; } if (grp->bin_size) size = grp->bin_size(kobj, *bin_attr, i); WARN(mode & ~(SYSFS_PREALLOC | 0664), "Attribute %s: Invalid permissions 0%o\n", (*bin_attr)->attr.name, mode); mode &= SYSFS_PREALLOC | 0664; error = sysfs_add_bin_file_mode_ns(parent, *bin_attr, mode, size, uid, gid, 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; kuid_t uid; kgid_t gid; int error; if (WARN_ON(!kobj || (!update && !kobj->sd))) return -EINVAL; /* Updates may happen before the object has been instantiated */ if (unlikely(update && !kobj->sd)) return -EINVAL; if (!grp->attrs && !grp->bin_attrs) { pr_debug("sysfs: (bin_)attrs not set by subsystem for group: %s/%s, skipping\n", kobj->name, grp->name ?: ""); return 0; } kobject_get_ownership(kobj, &uid, &gid); if (grp->name) { umode_t mode = __first_visible(grp, kobj); if (mode & SYSFS_GROUP_INVISIBLE) mode = 0; else mode = S_IRWXU | S_IRUGO | S_IXUGO; if (update) { kn = kernfs_find_and_get(kobj->sd, grp->name); if (!kn) { pr_debug("attr grp %s/%s not created yet\n", kobj->name, grp->name); /* may have been invisible prior to this update */ update = 0; } else if (!mode) { sysfs_remove_group(kobj, grp); kernfs_put(kn); return 0; } } if (!update) { if (!mode) return 0; kn = kernfs_create_dir_ns(kobj->sd, grp->name, mode, uid, gid, kobj, NULL); 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, uid, gid, grp, update); if (error) { if (grp->name && !update) kernfs_remove(kn); } kernfs_put(kn); if (grp->name && update) 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); static int internal_create_groups(struct kobject *kobj, int update, const struct attribute_group *const *groups){ int error = 0; int i; if (!groups) return 0; for (i = 0; groups[i]; i++) { error = internal_create_group(kobj, update, groups[i]); if (error) { while (--i >= 0) sysfs_remove_group(kobj, groups[i]); break; } } return error;} /** * 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 *const *groups){ return internal_create_groups(kobj, 0, groups);}EXPORT_SYMBOL_GPL(sysfs_create_groups); /** * sysfs_update_groups - given a directory kobject, create a bunch of attribute groups * @kobj: The kobject to update the group on * @groups: The attribute groups to update, NULL terminated * * This function update a bunch of attribute groups. If an error occurs when * updating a group, all previously updated groups will be removed together * with already existing (not updated) attributes. * * Returns 0 on success or error code from sysfs_update_group on failure. */int sysfs_update_groups(struct kobject *kobj, const struct attribute_group *const *groups){ return internal_create_groups(kobj, 1, groups);}EXPORT_SYMBOL_GPL(sysfs_update_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. Changing a group's name (subdirectory name under * kobj's directory in sysfs) is not allowed. * * 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) { pr_debug("sysfs group '%s' not found for kobject '%s'\n", grp->name, 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 *const *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 named 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, the .name field is * NULL 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; kuid_t uid; kgid_t gid; int error = 0; struct attribute *const *attr; int i; parent = kernfs_find_and_get(kobj->sd, grp->name); if (!parent) return -ENOENT; kobject_get_ownership(kobj, &uid, &gid); for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr)) error = sysfs_add_file_mode_ns(parent, *attr, (*attr)->mode, uid, gid, NULL); 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 named 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. * @symlink_name: The name of the symlink file (target_name will be * considered if symlink_name is NULL). */int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, struct kobject *target_kobj, const char *target_name, const char *symlink_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, target_name); if (!entry) { kernfs_put(target); return -ENOENT; } if (!symlink_name) symlink_name = target_name; link = kernfs_create_link(kobj->sd, symlink_name, entry); if (PTR_ERR(link) == -EEXIST) sysfs_warn_dup(kobj->sd, symlink_name); Lines 1–500 of 638. Load more
// SPDX-License-Identifier: GPL-2.0 /* * 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 */ #include <linux/kobject.h> #include <linux/module.h> #include <linux/dcache.h> #include <linux/namei.h> #include <linux/err.h> #include <linux/fs.h> #include "sysfs.h" static void remove_files(struct kernfs_node *parent, const struct attribute_group *grp) { struct attribute *const *attr; const 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 umode_t __first_visible(const struct attribute_group *grp, struct kobject *kobj) { if (grp->attrs && grp->attrs[0] && grp->is_visible) return grp->is_visible(kobj, grp->attrs[0], 0); if (grp->attrs && grp->attrs[0] && grp->is_visible_const) return grp->is_visible_const(kobj, grp->attrs[0], 0); if (grp->bin_attrs && grp->bin_attrs[0] && grp->is_bin_visible) return grp->is_bin_visible(kobj, grp->bin_attrs[0], 0); return 0; } static int create_files(struct kernfs_node *parent, struct kobject *kobj, kuid_t uid, kgid_t gid, const struct attribute_group *grp, int update) { struct attribute *const *attr; const 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 || grp->is_visible_const) { if (grp->is_visible) mode = grp->is_visible(kobj, *attr, i); else mode = grp->is_visible_const(kobj, *attr, i); mode &= ~SYSFS_GROUP_INVISIBLE; 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, mode, uid, gid, NULL); if (unlikely(error)) break; } if (error) { remove_files(parent, grp); goto exit; } } if (grp->bin_attrs) { for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) { umode_t mode = (*bin_attr)->attr.mode; size_t size = (*bin_attr)->size; if (update) kernfs_remove_by_name(parent, (*bin_attr)->attr.name); if (grp->is_bin_visible) { mode = grp->is_bin_visible(kobj, *bin_attr, i); mode &= ~SYSFS_GROUP_INVISIBLE; if (!mode) continue; } if (grp->bin_size) size = grp->bin_size(kobj, *bin_attr, i); WARN(mode & ~(SYSFS_PREALLOC | 0664), "Attribute %s: Invalid permissions 0%o\n", (*bin_attr)->attr.name, mode); mode &= SYSFS_PREALLOC | 0664; error = sysfs_add_bin_file_mode_ns(parent, *bin_attr, mode, size, uid, gid, 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; kuid_t uid; kgid_t gid; int error; if (WARN_ON(!kobj || (!update && !kobj->sd))) return -EINVAL; /* Updates may happen before the object has been instantiated */ if (unlikely(update && !kobj->sd)) return -EINVAL; if (!grp->attrs && !grp->bin_attrs) { pr_debug("sysfs: (bin_)attrs not set by subsystem for group: %s/%s, skipping\n", kobj->name, grp->name ?: ""); return 0; } kobject_get_ownership(kobj, &uid, &gid); if (grp->name) { umode_t mode = __first_visible(grp, kobj); if (mode & SYSFS_GROUP_INVISIBLE) mode = 0; else mode = S_IRWXU | S_IRUGO | S_IXUGO; if (update) { kn = kernfs_find_and_get(kobj->sd, grp->name); if (!kn) { pr_debug("attr grp %s/%s not created yet\n", kobj->name, grp->name); /* may have been invisible prior to this update */ update = 0; } else if (!mode) { sysfs_remove_group(kobj, grp); kernfs_put(kn); return 0; } } if (!update) { if (!mode) return 0; kn = kernfs_create_dir_ns(kobj->sd, grp->name, mode, uid, gid, kobj, NULL); 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, uid, gid, grp, update); if (error) { if (grp->name && !update) kernfs_remove(kn); } kernfs_put(kn); if (grp->name && update) 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); static int internal_create_groups(struct kobject *kobj, int update, const struct attribute_group *const *groups) { int error = 0; int i; if (!groups) return 0; for (i = 0; groups[i]; i++) { error = internal_create_group(kobj, update, groups[i]); if (error) { while (--i >= 0) sysfs_remove_group(kobj, groups[i]); break; } } return error; } /** * 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 *const *groups) { return internal_create_groups(kobj, 0, groups); } EXPORT_SYMBOL_GPL(sysfs_create_groups); /** * sysfs_update_groups - given a directory kobject, create a bunch of attribute groups * @kobj: The kobject to update the group on * @groups: The attribute groups to update, NULL terminated * * This function update a bunch of attribute groups. If an error occurs when * updating a group, all previously updated groups will be removed together * with already existing (not updated) attributes. * * Returns 0 on success or error code from sysfs_update_group on failure. */ int sysfs_update_groups(struct kobject *kobj, const struct attribute_group *const *groups) { return internal_create_groups(kobj, 1, groups); } EXPORT_SYMBOL_GPL(sysfs_update_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. Changing a group's name (subdirectory name under * kobj's directory in sysfs) is not allowed. * * 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) { pr_debug("sysfs group '%s' not found for kobject '%s'\n", grp->name, 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 *const *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 named 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, the .name field is * NULL 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; kuid_t uid; kgid_t gid; int error = 0; struct attribute *const *attr; int i; parent = kernfs_find_and_get(kobj->sd, grp->name); if (!parent) return -ENOENT; kobject_get_ownership(kobj, &uid, &gid); for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr)) error = sysfs_add_file_mode_ns(parent, *attr, (*attr)->mode, uid, gid, NULL); 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 named 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. * @symlink_name: The name of the symlink file (target_name will be * considered if symlink_name is NULL). */ int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, struct kobject *target_kobj, const char *target_name, const char *symlink_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, target_name); if (!entry) { kernfs_put(target); return -ENOENT; } if (!symlink_name) symlink_name = target_name; link = kernfs_create_link(kobj->sd, symlink_name, entry); if (PTR_ERR(link) == -EEXIST) sysfs_warn_dup(kobj->sd, symlink_name);