Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/nfs/sysfs.c b/fs/nfs/sysfs.c
new file mode 100644
index 0000000..4f3390b
--- /dev/null
+++ b/fs/nfs/sysfs.c
@@ -0,0 +1,187 @@
+// 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);
+ return scnprintf(buf, PAGE_SIZE, "%s\n", c->identifier);
+}
+
+/* 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 = xchg(&c->identifier, p);
+ 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);
+
+ if (c->identifier)
+ kfree(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;
+ }
+}