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
  16 #include "state.h"
  17 #include "netns.h"
  18
  19 struct nfsd_fault_inject_op {
  20         char *file;
  21         u64 (*get)(void);
  22         u64 (*set_val)(u64);
  23         u64 (*set_clnt)(struct sockaddr_storage *, size_t);
  24 };
  25
  26 static struct dentry *debug_dir;
  27
  28 static ssize_t fault_inject_read(struct file *file, char __user *buf,
  29                                  size_t len, loff_t *ppos)
  30 {
  31         static u64 val;
  32         char read_buf[25];
  33         size_t size;
  34         loff_t pos = *ppos;
  35         struct nfsd_fault_inject_op *op = file_inode(file)->i_private;
  36
  37         if (!pos)
  38                 val = op->get();
  39         size = scnprintf(read_buf, sizeof(read_buf), "%llu\n", val);
  40
  41         return simple_read_from_buffer(buf, len, ppos, read_buf, size);
  42 }
  43
  44 static ssize_t fault_inject_write(struct file *file, const char __user *buf,
  45                                   size_t len, loff_t *ppos)
  46 {
  47         char write_buf[INET6_ADDRSTRLEN];
  48         size_t size = min(sizeof(write_buf) - 1, len);
  49         struct net *net = current->nsproxy->net_ns;
  50         struct sockaddr_storage sa;
  51         struct nfsd_fault_inject_op *op = file_inode(file)->i_private;
  52         u64 val;
  53         char *nl;
  54
  55         if (copy_from_user(write_buf, buf, size))
  56                 return -EFAULT;
  57         write_buf[size] = '\0';
  58
  59         /* Deal with any embedded newlines in the string */
  60         nl = strchr(write_buf, '\n');
  61         if (nl) {
  62                 size = nl - write_buf;
  63                 *nl = '\0';
  64         }
  65
  66         size = rpc_pton(net, write_buf, size, (struct sockaddr *)&sa, sizeof(sa));
  67         if (size > 0) {
  68                 val = op->set_clnt(&sa, size);
  69                 if (val)
  70                         pr_info("NFSD [%s]: Client %s had %llu state object(s)\n",
  71                                 op->file, write_buf, val);
  72         } else {
  73                 val = simple_strtoll(write_buf, NULL, 0);
  74                 if (val == 0)
  75                         pr_info("NFSD Fault Injection: %s (all)", op->file);
  76                 else
  77                         pr_info("NFSD Fault Injection: %s (n = %llu)",
  78                                 op->file, val);
  79                 val = op->set_val(val);
  80                 pr_info("NFSD: %s: found %llu", op->file, val);
  81         }
  82         return len; /* on success, claim we got the whole input */
  83 }
  84
  85 static const struct file_operations fops_nfsd = {
  86         .owner   = THIS_MODULE,
  87         .read    = fault_inject_read,
  88         .write   = fault_inject_write,
  89 };
  90
  91 void nfsd_fault_inject_cleanup(void)
  92 {
  93         debugfs_remove_recursive(debug_dir);
  94 }
  95
  96 static struct nfsd_fault_inject_op inject_ops[] = {
  97         {
  98                 .file     = "forget_clients",
  99                 .get      = nfsd_inject_print_clients,
 100                 .set_val  = nfsd_inject_forget_clients,
 101                 .set_clnt = nfsd_inject_forget_client,
 102         },
 103         {
 104                 .file     = "forget_locks",
 105                 .get      = nfsd_inject_print_locks,
 106                 .set_val  = nfsd_inject_forget_locks,
 107                 .set_clnt = nfsd_inject_forget_client_locks,
 108         },
 109         {
 110                 .file     = "forget_openowners",
 111                 .get      = nfsd_inject_print_openowners,
 112                 .set_val  = nfsd_inject_forget_openowners,
 113                 .set_clnt = nfsd_inject_forget_client_openowners,
 114         },
 115         {
 116                 .file     = "forget_delegations",
 117                 .get      = nfsd_inject_print_delegations,
 118                 .set_val  = nfsd_inject_forget_delegations,
 119                 .set_clnt = nfsd_inject_forget_client_delegations,
 120         },
 121         {
 122                 .file     = "recall_delegations",
 123                 .get      = nfsd_inject_print_delegations,
 124                 .set_val  = nfsd_inject_recall_delegations,
 125                 .set_clnt = nfsd_inject_recall_client_delegations,
 126         },
 127 };
 128
 129 #define NUM_INJECT_OPS (sizeof(inject_ops)/sizeof(struct nfsd_fault_inject_op))
 130
 131 int nfsd_fault_inject_init(void)
 132 {
 133         unsigned int i;
 134         struct nfsd_fault_inject_op *op;
 135         umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
 136
 137         debug_dir = debugfs_create_dir("nfsd", NULL);
 138         if (!debug_dir)
 139                 goto fail;
 140
 141         for (i = 0; i < NUM_INJECT_OPS; i++) {
 142                 op = &inject_ops[i];
 143                 if (!debugfs_create_file(op->file, mode, debug_dir, op, &fops_nfsd))
 144                         goto fail;
 145         }
 146         return 0;
 147
 148 fail:
 149         nfsd_fault_inject_cleanup();
 150         return -ENOMEM;
 151 }