// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2019 Hammerspace Inc */ #include <linux/module.h> #include <linux/kobject.h> #include <linux/sysfs.h> #include <linux/fs.h> #include <linux/slab.h> #include <linux/netdevice.h> #include <linux/string.h> #include <linux/nfs_fs.h> #include <linux/rcupdate.h> #include "nfs4_fs.h" #include "netns.h" #include "sysfs.h" struct kobject *nfs_client_kobj; static struct kset *nfs_client_kset; static void nfs_netns_object_release(struct kobject *kobj) { kfree(kobj); } static const struct kobj_ns_type_operations *nfs_netns_object_child_ns_type( struct kobject *kobj) { return &net_ns_type_operations; } static struct kobj_type nfs_netns_object_type = { .release = nfs_netns_object_release, .sysfs_ops = &kobj_sysfs_ops, .child_ns_type = nfs_netns_object_child_ns_type, }; static struct kobject *nfs_netns_object_alloc(const char *name, struct kset *kset, struct kobject *parent) { struct kobject *kobj; kobj = kzalloc(sizeof(*kobj), GFP_KERNEL); if (kobj) { kobj->kset = kset; if (kobject_init_and_add(kobj, &nfs_netns_object_type, parent, "%s", name) == 0) return kobj; kobject_put(kobj); } return NULL; } int nfs_sysfs_init(void) { nfs_client_kset = kset_create_and_add("nfs", NULL, fs_kobj); if (!nfs_client_kset) return -ENOMEM; nfs_client_kobj = nfs_netns_object_alloc("net", nfs_client_kset, NULL); if (!nfs_client_kobj) { kset_unregister(nfs_client_kset); nfs_client_kset = NULL; return -ENOMEM; } return 0; } void nfs_sysfs_exit(void) { kobject_put(nfs_client_kobj); kset_unregister(nfs_client_kset); } static ssize_t nfs_netns_identifier_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { struct nfs_netns_client *c = container_of(kobj, struct nfs_netns_client, kobject); ssize_t ret; rcu_read_lock(); ret = scnprintf(buf, PAGE_SIZE, "%s\n", rcu_dereference(c->identifier)); rcu_read_unlock(); return ret; } /* Strip trailing '\n' */ static size_t nfs_string_strip(const char *c, size_t len) { while (len > 0 && c[len-1] == '\n') --len; return len; } static ssize_t nfs_netns_identifier_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { struct nfs_netns_client *c = container_of(kobj, struct nfs_netns_client, kobject); const char *old; char *p; size_t len; len = nfs_string_strip(buf, min_t(size_t, count, CONTAINER_ID_MAXLEN)); if (!len) return 0; p = kmemdup_nul(buf, len, GFP_KERNEL); if (!p) return -ENOMEM; old = rcu_dereference_protected(xchg(&c->identifier, (char __rcu *)p), 1); if (old) { synchronize_rcu(); kfree(old); } return count; } static void nfs_netns_client_release(struct kobject *kobj) { struct nfs_netns_client *c = container_of(kobj, struct nfs_netns_client, kobject); kfree(rcu_dereference_raw(c->identifier)); kfree(c); } static const void *nfs_netns_client_namespace(struct kobject *kobj) { return container_of(kobj, struct nfs_netns_client, kobject)->net; } static struct kobj_attribute nfs_netns_client_id = __ATTR(identifier, 0644, nfs_netns_identifier_show, nfs_netns_identifier_store); static struct attribute *nfs_netns_client_attrs[] = { &nfs_netns_client_id.attr, NULL, }; static struct kobj_type nfs_netns_client_type = { .release = nfs_netns_client_release, .default_attrs = nfs_netns_client_attrs, .sysfs_ops = &kobj_sysfs_ops, .namespace = nfs_netns_client_namespace, }; static struct nfs_netns_client *nfs_netns_client_alloc(struct kobject *parent, struct net *net) { struct nfs_netns_client *p; p = kzalloc(sizeof(*p), GFP_KERNEL); if (p) { p->net = net; p->kobject.kset = nfs_client_kset; if (kobject_init_and_add(&p->kobject, &nfs_netns_client_type, parent, "nfs_client") == 0) return p; kobject_put(&p->kobject); } return NULL; } void nfs_netns_sysfs_setup(struct nfs_net *netns, struct net *net) { struct nfs_netns_client *clp; clp = nfs_netns_client_alloc(nfs_client_kobj, net); if (clp) { netns->nfs_client = clp; kobject_uevent(&clp->kobject, KOBJ_ADD); } } void nfs_netns_sysfs_destroy(struct nfs_net *netns) { struct nfs_netns_client *clp = netns->nfs_client; if (clp) { kobject_uevent(&clp->kobject, KOBJ_REMOVE); kobject_del(&clp->kobject); kobject_put(&clp->kobject); netns->nfs_client = NULL; } }