LXR linux/fs/nfsd/fault

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2011 Bryan Schumaker <bjschuma@netapp.com>
   4 *
   5 * Uses debugfs to create fault injection points for client testing
   6 */
   7
   8#include <linux/types.h>
   9#include <linux/fs.h>
  10#include <linux/debugfs.h>
  11#include <linux/module.h>
  12#include <linux/nsproxy.h>
  13#include <linux/sunrpc/addr.h>
  14#include <linux/uaccess.h>
  15#include <linux/kernel.h>
  16
  17#include "state.h"
  18#include "netns.h"
  19
  20struct nfsd_fault_inject_op {
  21        char *file;
  22        u64 (*get)(void);
  23        u64 (*set_val)(u64);
  24        u64 (*set_clnt)(struct sockaddr_storage *, size_t);
  25};
  26
  27static struct dentry *debug_dir;
  28
  29static ssize_t fault_inject_read(struct file *file, char __user *buf,
  30                                 size_t len, loff_t *ppos)
  31{
  32        static u64 val;
  33        char read_buf[25];
  34        size_t size;
  35        loff_t pos = *ppos;
  36        struct nfsd_fault_inject_op *op = file_inode(file)->i_private;
  37
  38        if (!pos)
  39                val = op->get();
  40        size = scnprintf(read_buf, sizeof(read_buf), "%llu\n", val);
  41
  42        return simple_read_from_buffer(buf, len, ppos, read_buf, size);
  43}
  44
  45static ssize_t fault_inject_write(struct file *file, const char __user *buf,
  46                                  size_t len, loff_t *ppos)
  47{
  48        char write_buf[INET6_ADDRSTRLEN];
  49        size_t size = min(sizeof(write_buf) - 1, len);
  50        struct net *net = current->nsproxy->net_ns;
  51        struct sockaddr_storage sa;
  52        struct nfsd_fault_inject_op *op = file_inode(file)->i_private;
  53        u64 val;
  54        char *nl;
  55
  56        if (copy_from_user(write_buf, buf, size))
  57                return -EFAULT;
  58        write_buf[size] = '\0';
  59
  60        /* Deal with any embedded newlines in the string */
  61        nl = strchr(write_buf, '\n');
  62        if (nl) {
  63                size = nl - write_buf;
  64                *nl = '\0';
  65        }
  66
  67        size = rpc_pton(net, write_buf, size, (struct sockaddr *)&sa, sizeof(sa));
  68        if (size > 0) {
  69                val = op->set_clnt(&sa, size);
  70                if (val)
  71                        pr_info("NFSD [%s]: Client %s had %llu state object(s)\n",
  72                                op->file, write_buf, val);
  73        } else {
  74                val = simple_strtoll(write_buf, NULL, 0);
  75                if (val == 0)
  76                        pr_info("NFSD Fault Injection: %s (all)", op->file);
  77                else
  78                        pr_info("NFSD Fault Injection: %s (n = %llu)",
  79                                op->file, val);
  80                val = op->set_val(val);
  81                pr_info("NFSD: %s: found %llu", op->file, val);
  82        }
  83        return len; /* on success, claim we got the whole input */
  84}
  85
  86static const struct file_operations fops_nfsd = {
  87        .owner   = THIS_MODULE,
  88        .read    = fault_inject_read,
  89        .write   = fault_inject_write,
  90};
  91
  92void nfsd_fault_inject_cleanup(void)
  93{
  94        debugfs_remove_recursive(debug_dir);
  95}
  96
  97static struct nfsd_fault_inject_op inject_ops[] = {
  98        {
  99                .file     = "forget_clients",
 100                .get      = nfsd_inject_print_clients,
 101                .set_val  = nfsd_inject_forget_clients,
 102                .set_clnt = nfsd_inject_forget_client,
 103        },
 104        {
 105                .file     = "forget_locks",
 106                .get      = nfsd_inject_print_locks,
 107                .set_val  = nfsd_inject_forget_locks,
 108                .set_clnt = nfsd_inject_forget_client_locks,
 109        },
 110        {
 111                .file     = "forget_openowners",
 112                .get      = nfsd_inject_print_openowners,
 113                .set_val  = nfsd_inject_forget_openowners,
 114                .set_clnt = nfsd_inject_forget_client_openowners,
 115        },
 116        {
 117                .file     = "forget_delegations",
 118                .get      = nfsd_inject_print_delegations,
 119                .set_val  = nfsd_inject_forget_delegations,
 120                .set_clnt = nfsd_inject_forget_client_delegations,
 121        },
 122        {
 123                .file     = "recall_delegations",
 124                .get      = nfsd_inject_print_delegations,
 125                .set_val  = nfsd_inject_recall_delegations,
 126                .set_clnt = nfsd_inject_recall_client_delegations,
 127        },
 128};
 129
 130void nfsd_fault_inject_init(void)
 131{
 132        unsigned int i;
 133        struct nfsd_fault_inject_op *op;
 134        umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
 135
 136        debug_dir = debugfs_create_dir("nfsd", NULL);
 137
 138        for (i = 0; i < ARRAY_SIZE(inject_ops); i++) {
 139                op = &inject_ops[i];
 140                debugfs_create_file(op->file, mode, debug_dir, op, &fops_nfsd);
 141        }
 142}
 143