fs/nfsd/fault_inject.c

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