From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- fs/nfs/sysfs.c | 474 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 474 insertions(+) create mode 100644 fs/nfs/sysfs.c (limited to 'fs/nfs/sysfs.c') diff --git a/fs/nfs/sysfs.c b/fs/nfs/sysfs.c new file mode 100644 index 000000000..3a197252a --- /dev/null +++ b/fs/nfs/sysfs.c @@ -0,0 +1,474 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2019 Hammerspace Inc + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" +#include "nfs4_fs.h" +#include "netns.h" +#include "sysfs.h" + +static struct kset *nfs_kset; + +static void nfs_kset_release(struct kobject *kobj) +{ + struct kset *kset = container_of(kobj, struct kset, kobj); + kfree(kset); +} + +static const struct kobj_ns_type_operations *nfs_netns_object_child_ns_type( + const struct kobject *kobj) +{ + return &net_ns_type_operations; +} + +static struct kobj_type nfs_kset_type = { + .release = nfs_kset_release, + .sysfs_ops = &kobj_sysfs_ops, + .child_ns_type = nfs_netns_object_child_ns_type, +}; + +int nfs_sysfs_init(void) +{ + int ret; + + nfs_kset = kzalloc_obj(*nfs_kset); + if (!nfs_kset) + return -ENOMEM; + + ret = kobject_set_name(&nfs_kset->kobj, "nfs"); + if (ret) { + kfree(nfs_kset); + return ret; + } + + nfs_kset->kobj.parent = fs_kobj; + nfs_kset->kobj.ktype = &nfs_kset_type; + nfs_kset->kobj.kset = NULL; + + ret = kset_register(nfs_kset); + if (ret) { + kfree(nfs_kset); + return ret; + } + + return 0; +} + +void nfs_sysfs_exit(void) +{ + kset_unregister(nfs_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 = sysfs_emit(buf, "%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)); +} + +static const struct ns_common *nfs_netns_client_namespace(const struct kobject *kobj) +{ + return to_ns_common(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, +}; +ATTRIBUTE_GROUPS(nfs_netns_client); + +static struct kobj_type nfs_netns_client_type = { + .release = nfs_netns_client_release, + .default_groups = nfs_netns_client_groups, + .sysfs_ops = &kobj_sysfs_ops, + .namespace = nfs_netns_client_namespace, +}; + +static void nfs_netns_object_release(struct kobject *kobj) +{ + struct nfs_netns_client *c = container_of(kobj, + struct nfs_netns_client, + nfs_net_kobj); + kfree(c); +} + +static const struct ns_common *nfs_netns_namespace(const struct kobject *kobj) +{ + return to_ns_common(container_of(kobj, struct nfs_netns_client, + nfs_net_kobj)->net); +} + +static struct kobj_type nfs_netns_object_type = { + .release = nfs_netns_object_release, + .sysfs_ops = &kobj_sysfs_ops, + .namespace = nfs_netns_namespace, +}; + +static struct nfs_netns_client *nfs_netns_client_alloc(struct kobject *parent, + struct net *net) +{ + struct nfs_netns_client *p; + + p = kzalloc_obj(*p); + if (p) { + p->net = net; + p->kobject.kset = nfs_kset; + p->nfs_net_kobj.kset = nfs_kset; + + if (kobject_init_and_add(&p->nfs_net_kobj, &nfs_netns_object_type, + parent, "net") != 0) { + kobject_put(&p->nfs_net_kobj); + return NULL; + } + + if (kobject_init_and_add(&p->kobject, &nfs_netns_client_type, + &p->nfs_net_kobj, "nfs_client") == 0) + return p; + + kobject_put(&p->kobject); + kobject_put(&p->nfs_net_kobj); + } + 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_kset->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); + kobject_del(&clp->nfs_net_kobj); + kobject_put(&clp->nfs_net_kobj); + netns->nfs_client = NULL; + } +} + +static bool shutdown_match_client(const struct rpc_task *task, const void *data) +{ + return true; +} + +static void shutdown_client(struct rpc_clnt *clnt) +{ + clnt->cl_shutdown = 1; + rpc_cancel_tasks(clnt, -EIO, shutdown_match_client, NULL); +} + +/* + * Shut down the nfs_client only once all the superblocks + * have been shut down. + */ +static void shutdown_nfs_client(struct nfs_client *clp) +{ + struct nfs_server *server; + rcu_read_lock(); + list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { + if (!(server->flags & NFS_MOUNT_SHUTDOWN)) { + rcu_read_unlock(); + return; + } + } + rcu_read_unlock(); + nfs_mark_client_ready(clp, -EIO); + shutdown_client(clp->cl_rpcclient); +} + +static ssize_t +shutdown_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + struct nfs_server *server = container_of(kobj, struct nfs_server, kobj); + bool shutdown = server->flags & NFS_MOUNT_SHUTDOWN; + return sysfs_emit(buf, "%d\n", shutdown); +} + +static ssize_t +shutdown_store(struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t count) +{ + struct nfs_server *server; + int ret, val; + + server = container_of(kobj, struct nfs_server, kobj); + + ret = kstrtoint(buf, 0, &val); + if (ret) + return ret; + + if (val != 1) + return -EINVAL; + + /* already shut down? */ + if (server->flags & NFS_MOUNT_SHUTDOWN) + goto out; + + server->flags |= NFS_MOUNT_SHUTDOWN; + shutdown_client(server->client); + + if (!IS_ERR(server->client_acl)) + shutdown_client(server->client_acl); + + if (server->nlm_host) + nlmclnt_shutdown_rpc_clnt(server->nlm_host); +out: + shutdown_nfs_client(server->nfs_client); + return count; +} + +static struct kobj_attribute nfs_sysfs_attr_shutdown = __ATTR_RW(shutdown); + +#if IS_ENABLED(CONFIG_NFS_V4) +static ssize_t +implid_domain_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + struct nfs_server *server = container_of(kobj, struct nfs_server, kobj); + struct nfs41_impl_id *impl_id = server->nfs_client->cl_implid; + + if (!impl_id || strlen(impl_id->domain) == 0) + return 0; //sysfs_emit(buf, ""); + return sysfs_emit(buf, "%s\n", impl_id->domain); +} + +static struct kobj_attribute nfs_sysfs_attr_implid_domain = __ATTR_RO(implid_domain); + + +static ssize_t +implid_name_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + struct nfs_server *server = container_of(kobj, struct nfs_server, kobj); + struct nfs41_impl_id *impl_id = server->nfs_client->cl_implid; + + if (!impl_id || strlen(impl_id->name) == 0) + return 0; //sysfs_emit(buf, ""); + return sysfs_emit(buf, "%s\n", impl_id->name); +} + +static struct kobj_attribute nfs_sysfs_attr_implid_name = __ATTR_RO(implid_name); + +#endif /* IS_ENABLED(CONFIG_NFS_V4) */ + +#define RPC_CLIENT_NAME_SIZE 64 + +void nfs_sysfs_link_rpc_client(struct nfs_server *server, + struct rpc_clnt *clnt, const char *uniq) +{ + char name[RPC_CLIENT_NAME_SIZE]; + int ret; + + strscpy(name, clnt->cl_program->name, sizeof(name)); + strncat(name, uniq ? uniq : "", sizeof(name) - strlen(name) - 1); + strncat(name, "_client", sizeof(name) - strlen(name) - 1); + + ret = sysfs_create_link_nowarn(&server->kobj, + &clnt->cl_sysfs->kobject, name); + if (ret < 0) + pr_warn("NFS: can't create link to %s in sysfs (%d)\n", + name, ret); +} +EXPORT_SYMBOL_GPL(nfs_sysfs_link_rpc_client); + +static void nfs_sysfs_sb_release(struct kobject *kobj) +{ + /* no-op: why? see lib/kobject.c kobject_cleanup() */ +} + +static const struct ns_common *nfs_netns_server_namespace(const struct kobject *kobj) +{ + return to_ns_common(container_of(kobj, struct nfs_server, + kobj)->nfs_client->cl_net); +} + +static struct kobj_type nfs_sb_ktype = { + .release = nfs_sysfs_sb_release, + .sysfs_ops = &kobj_sysfs_ops, + .namespace = nfs_netns_server_namespace, + .child_ns_type = nfs_netns_object_child_ns_type, +}; + +#if IS_ENABLED(CONFIG_NFS_V4) +static void nfs_sysfs_add_nfsv41_server(struct nfs_server *server) +{ + int ret; + + if (!server->nfs_client->cl_implid) + return; + + ret = sysfs_create_file_ns(&server->kobj, &nfs_sysfs_attr_implid_domain.attr, + nfs_netns_server_namespace(&server->kobj)); + if (ret < 0) + pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n", + server->s_sysfs_id, ret); + + ret = sysfs_create_file_ns(&server->kobj, &nfs_sysfs_attr_implid_name.attr, + nfs_netns_server_namespace(&server->kobj)); + if (ret < 0) + pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n", + server->s_sysfs_id, ret); +} +#else /* CONFIG_NFS_V4 */ +static inline void nfs_sysfs_add_nfsv41_server(struct nfs_server *server) +{ +} +#endif /* CONFIG_NFS_V4 */ + +#if IS_ENABLED(CONFIG_NFS_LOCALIO) + +static ssize_t +localio_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + struct nfs_server *server = container_of(kobj, struct nfs_server, kobj); + bool localio = nfs_server_is_local(server->nfs_client); + return sysfs_emit(buf, "%d\n", localio); +} + +static struct kobj_attribute nfs_sysfs_attr_localio = __ATTR_RO(localio); + +static void nfs_sysfs_add_nfs_localio_server(struct nfs_server *server) +{ + int ret = sysfs_create_file_ns(&server->kobj, &nfs_sysfs_attr_localio.attr, + nfs_netns_server_namespace(&server->kobj)); + if (ret < 0) + pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n", + server->s_sysfs_id, ret); +} +#else +static inline void nfs_sysfs_add_nfs_localio_server(struct nfs_server *server) +{ +} +#endif /* IS_ENABLED(CONFIG_NFS_LOCALIO) */ + +void nfs_sysfs_add_server(struct nfs_server *server) +{ + int ret; + + ret = kobject_init_and_add(&server->kobj, &nfs_sb_ktype, + &nfs_kset->kobj, "server-%d", server->s_sysfs_id); + if (ret < 0) { + pr_warn("NFS: nfs sysfs add server-%d failed (%d)\n", + server->s_sysfs_id, ret); + return; + } + ret = sysfs_create_file_ns(&server->kobj, &nfs_sysfs_attr_shutdown.attr, + nfs_netns_server_namespace(&server->kobj)); + if (ret < 0) + pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n", + server->s_sysfs_id, ret); + + nfs_sysfs_add_nfsv41_server(server); + nfs_sysfs_add_nfs_localio_server(server); +} +EXPORT_SYMBOL_GPL(nfs_sysfs_add_server); + +void nfs_sysfs_move_server_to_sb(struct super_block *s) +{ + struct nfs_server *server = s->s_fs_info; + int ret; + + ret = kobject_rename(&server->kobj, s->s_id); + if (ret < 0) + pr_warn("NFS: rename sysfs %s failed (%d)\n", + server->kobj.name, ret); +} + +void nfs_sysfs_move_sb_to_server(struct nfs_server *server) +{ + const char *s; + int ret = -ENOMEM; + + s = kasprintf(GFP_KERNEL, "server-%d", server->s_sysfs_id); + if (s) { + ret = kobject_rename(&server->kobj, s); + kfree(s); + } + if (ret < 0) + pr_warn("NFS: rename sysfs %s failed (%d)\n", + server->kobj.name, ret); +} + +/* unlink, not dec-ref */ +void nfs_sysfs_remove_server(struct nfs_server *server) +{ + kobject_del(&server->kobj); +} -- cgit v1.3.1