// SPDX-License-Identifier: GPL-2.0
/*
 * Procfs support for lockd
 *
 * Copyright (c) 2014 Jeff Layton <jlayton@primarydata.com>
 */

#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <linux/nsproxy.h>
#include <net/net_namespace.h>

#include "netns.h"
#include "procfs.h"

/*
 * We only allow strings that start with 'Y', 'y', or '1'.
 */
static ssize_t
nlm_end_grace_write(struct file *file, const char __user *buf, size_t size,
                    loff_t *pos)
{
        char *data;
        struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
                                           lockd_net_id);

        if (size < 1)
                return -EINVAL;

        data = simple_transaction_get(file, buf, size);
        if (IS_ERR(data))
                return PTR_ERR(data);

        switch(data[0]) {
        case 'Y':
        case 'y':
        case '1':
                locks_end_grace(&ln->lockd_manager);
                break;
        default:
                return -EINVAL;
        }

        return size;
}

static ssize_t
nlm_end_grace_read(struct file *file, char __user *buf, size_t size,
                   loff_t *pos)
{
        struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
                                           lockd_net_id);
        char resp[3];

        resp[0] = list_empty(&ln->lockd_manager.list) ? 'Y' : 'N';
        resp[1] = '\n';
        resp[2] = '\0';

        return simple_read_from_buffer(buf, size, pos, resp, sizeof(resp));
}

static const struct proc_ops lockd_end_grace_proc_ops = {
        .proc_write     = nlm_end_grace_write,
        .proc_read      = nlm_end_grace_read,
        .proc_lseek     = default_llseek,
        .proc_release   = simple_transaction_release,
};

int __init
lockd_create_procfs(void)
{
        struct proc_dir_entry *entry;

        entry = proc_mkdir("fs/lockd", NULL);
        if (!entry)
                return -ENOMEM;
        entry = proc_create("nlm_end_grace", S_IRUGO|S_IWUSR, entry,
                            &lockd_end_grace_proc_ops);
        if (!entry) {
                remove_proc_entry("fs/lockd", NULL);
                return -ENOMEM;
        }
        return 0;
}

void __exit
lockd_remove_procfs(void)
{
        remove_proc_entry("fs/lockd/nlm_end_grace", NULL);
        remove_proc_entry("fs/lockd", NULL);
}