1 files changed, 361 insertions, 0 deletions
diff --git a/fs/nfs/sysfs.c b/fs/nfs/sysfs.c
new file mode 100644
index 0000000000..bf378ecd5d
--- /dev/null
+++ b/fs/nfs/sysfs.c
@@ -0,0 +1,361 @@
+// 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 <linux/lockd/lockd.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(sizeof(*nfs_kset), GFP_KERNEL);
+	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 void *nfs_netns_client_namespace(const 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,
+};
+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 void *nfs_netns_namespace(const struct kobject *kobj)
+{
+	return 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(sizeof(*p), GFP_KERNEL);
+	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);
+	}
+	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);
+}
+
+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);
+	shutdown_client(server->nfs_client->cl_rpcclient);
+
+	if (!IS_ERR(server->client_acl))
+		shutdown_client(server->client_acl);
+
+	if (server->nlm_host)
+		shutdown_client(server->nlm_host->h_rpcclnt);
+out:
+	return count;
+}
+
+static struct kobj_attribute nfs_sysfs_attr_shutdown = __ATTR_RW(shutdown);
+
+#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;
+
+	strcpy(name, clnt->cl_program->name);
+	strcat(name, uniq ? uniq : "");
+	strcat(name, "_client");
+
+	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 void *nfs_netns_server_namespace(const struct kobject *kobj)
+{
+	return 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,
+};
+
+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);
+}
+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);
+}