^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /* -*- mode: c; c-basic-offset: 8; -*-
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * vim: noexpandtab sw=8 ts=8 sts=0:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * item.c - library routines for handling generic config items
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Based on kobject:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * kobject is Copyright (c) 2002-2003 Patrick Mochel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * configfs Copyright (C) 2005 Oracle. All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * Please see the file Documentation/filesystems/configfs.rst for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * critical information about using the config_item interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/stat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/configfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) static inline struct config_item *to_item(struct list_head *entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) return container_of(entry, struct config_item, ci_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) /* Evil kernel */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) static void config_item_release(struct kref *kref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * config_item_init - initialize item.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * @item: item in question.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static void config_item_init(struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) kref_init(&item->ci_kref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) INIT_LIST_HEAD(&item->ci_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * config_item_set_name - Set the name of an item
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * @item: item.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * @fmt: The vsnprintf()'s format string.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) * If strlen(name) >= CONFIGFS_ITEM_NAME_LEN, then use a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * dynamically allocated string that @item->ci_name points to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * Otherwise, use the static @item->ci_namebuf array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) int config_item_set_name(struct config_item *item, const char *fmt, ...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) int limit = CONFIGFS_ITEM_NAME_LEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) int need;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) va_list args;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * First, try the static array
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) va_start(args, fmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) need = vsnprintf(item->ci_namebuf, limit, fmt, args);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) va_end(args);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) if (need < limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) name = item->ci_namebuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) va_start(args, fmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) name = kvasprintf(GFP_KERNEL, fmt, args);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) va_end(args);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) if (!name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) /* Free the old name, if necessary. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) if (item->ci_name && item->ci_name != item->ci_namebuf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) kfree(item->ci_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) /* Now, set the new name */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) item->ci_name = name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) EXPORT_SYMBOL(config_item_set_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) void config_item_init_type_name(struct config_item *item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) const struct config_item_type *type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) config_item_set_name(item, "%s", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) item->ci_type = type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) config_item_init(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) EXPORT_SYMBOL(config_item_init_type_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) void config_group_init_type_name(struct config_group *group, const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) const struct config_item_type *type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) config_item_set_name(&group->cg_item, "%s", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) group->cg_item.ci_type = type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) config_group_init(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) EXPORT_SYMBOL(config_group_init_type_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) struct config_item *config_item_get(struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) if (item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) kref_get(&item->ci_kref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) return item;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) EXPORT_SYMBOL(config_item_get);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) struct config_item *config_item_get_unless_zero(struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (item && kref_get_unless_zero(&item->ci_kref))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) return item;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) EXPORT_SYMBOL(config_item_get_unless_zero);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) static void config_item_cleanup(struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) const struct config_item_type *t = item->ci_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) struct config_group *s = item->ci_group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) struct config_item *parent = item->ci_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) pr_debug("config_item %s: cleaning up\n", config_item_name(item));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) if (item->ci_name != item->ci_namebuf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) kfree(item->ci_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) item->ci_name = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) if (t && t->ct_item_ops && t->ct_item_ops->release)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) t->ct_item_ops->release(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) if (s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) config_group_put(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) if (parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) config_item_put(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) static void config_item_release(struct kref *kref)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) config_item_cleanup(container_of(kref, struct config_item, ci_kref));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) * config_item_put - decrement refcount for item.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) * @item: item.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * Decrement the refcount, and if 0, call config_item_cleanup().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) void config_item_put(struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) if (item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) kref_put(&item->ci_kref, config_item_release);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) EXPORT_SYMBOL(config_item_put);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) * config_group_init - initialize a group for use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) * @group: config_group
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) void config_group_init(struct config_group *group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) config_item_init(&group->cg_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) INIT_LIST_HEAD(&group->cg_children);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) INIT_LIST_HEAD(&group->default_groups);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) EXPORT_SYMBOL(config_group_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * config_group_find_item - search for item in group.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) * @group: group we're looking in.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * @name: item's name.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) * Iterate over @group->cg_list, looking for a matching config_item.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) * If matching item is found take a reference and return the item.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) * Caller must have locked group via @group->cg_subsys->su_mtx.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) struct config_item *config_group_find_item(struct config_group *group,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) const char *name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) struct list_head *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) struct config_item *ret = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) list_for_each(entry, &group->cg_children) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) struct config_item *item = to_item(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) if (config_item_name(item) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) !strcmp(config_item_name(item), name)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) ret = config_item_get(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) EXPORT_SYMBOL(config_group_find_item);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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