fs/nfsd/fault_inject.c

   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
  20 struct 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
  27 static struct dentry *debug_dir;
  28
  29 static 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
  45 static 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
  86 static const struct file_operations fops_nfsd = {
  87         .owner   = THIS_MODULE,
  88         .read    = fault_inject_read,
  89         .write   = fault_inject_write,
  90 };
  91
  92 void nfsd_fault_inject_cleanup(void)
  93 {
  94         debugfs_remove_recursive(debug_dir);
  95 }
  96
  97 static 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
 130 int 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         if (!debug_dir)
 138                 goto fail;
 139
 140         for (i = 0; i < ARRAY_SIZE(inject_ops); i++) {
 141                 op = &inject_ops[i];
 142                 if (!debugfs_create_file(op->file, mode, debug_dir, op, &fops_nfsd))
 143                         goto fail;
 144         }
 145         return 0;
 146
 147 fail:
 148         nfsd_fault_inject_cleanup();
 149         return -ENOMEM;
 150 }