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)(struct nfsd_fault_inject_op *);
  21         u64 (*set_val)(struct nfsd_fault_inject_op *, u64);
  22         u64 (*set_clnt)(struct nfsd_fault_inject_op *,
  23                         struct sockaddr_storage *, size_t);
  24         u64 (*forget)(struct nfs4_client *, u64);
  25         u64 (*print)(struct nfs4_client *, u64);
  26 };
  27
  28 static struct dentry *debug_dir;
  29
  30 static u64 nfsd_inject_set(struct nfsd_fault_inject_op *op, u64 val)
  31 {
  32         u64 count;
  33
  34         nfs4_lock_state();
  35         count = nfsd_for_n_state(val, op->forget);
  36         nfs4_unlock_state();
  37         return count;
  38 }
  39
  40 static u64 nfsd_inject_set_client(struct nfsd_fault_inject_op *op,
  41                                    struct sockaddr_storage *addr,
  42                                    size_t addr_size)
  43 {
  44         struct nfs4_client *clp;
  45         u64 count = 0;
  46
  47         nfs4_lock_state();
  48         clp = nfsd_find_client(addr, addr_size);
  49         if (clp)
  50                 count = op->forget(clp, 0);
  51         nfs4_unlock_state();
  52         return count;
  53 }
  54
  55 static u64 nfsd_inject_get(struct nfsd_fault_inject_op *op)
  56 {
  57         u64 count;
  58
  59         nfs4_lock_state();
  60         count = nfsd_for_n_state(0, op->print);
  61         nfs4_unlock_state();
  62
  63         return count;
  64 }
  65
  66 static ssize_t fault_inject_read(struct file *file, char __user *buf,
  67                                  size_t len, loff_t *ppos)
  68 {
  69         static u64 val;
  70         char read_buf[25];
  71         size_t size;
  72         loff_t pos = *ppos;
  73         struct nfsd_fault_inject_op *op = file_inode(file)->i_private;
  74
  75         if (!pos)
  76                 val = op->get(op);
  77         size = scnprintf(read_buf, sizeof(read_buf), "%llu\n", val);
  78
  79         return simple_read_from_buffer(buf, len, ppos, read_buf, size);
  80 }
  81
  82 static ssize_t fault_inject_write(struct file *file, const char __user *buf,
  83                                   size_t len, loff_t *ppos)
  84 {
  85         char write_buf[INET6_ADDRSTRLEN];
  86         size_t size = min(sizeof(write_buf) - 1, len);
  87         struct net *net = current->nsproxy->net_ns;
  88         struct sockaddr_storage sa;
  89         struct nfsd_fault_inject_op *op = file_inode(file)->i_private;
  90         u64 val;
  91         char *nl;
  92
  93         if (copy_from_user(write_buf, buf, size))
  94                 return -EFAULT;
  95         write_buf[size] = '\0';
  96
  97         /* Deal with any embedded newlines in the string */
  98         nl = strchr(write_buf, '\n');
  99         if (nl) {
 100                 size = nl - write_buf;
 101                 *nl = '\0';
 102         }
 103
 104         size = rpc_pton(net, write_buf, size, (struct sockaddr *)&sa, sizeof(sa));
 105         if (size > 0) {
 106                 val = op->set_clnt(op, &sa, size);
 107                 if (val)
 108                         pr_info("NFSD [%s]: Client %s had %llu state object(s)\n",
 109                                 op->file, write_buf, val);
 110         } else {
 111                 val = simple_strtoll(write_buf, NULL, 0);
 112                 if (val == 0)
 113                         pr_info("NFSD Fault Injection: %s (all)", op->file);
 114                 else
 115                         pr_info("NFSD Fault Injection: %s (n = %llu)",
 116                                 op->file, val);
 117                 val = op->set_val(op, val);
 118                 pr_info("NFSD: %s: found %llu", op->file, val);
 119         }
 120         return len; /* on success, claim we got the whole input */
 121 }
 122
 123 static const struct file_operations fops_nfsd = {
 124         .owner   = THIS_MODULE,
 125         .read    = fault_inject_read,
 126         .write   = fault_inject_write,
 127 };
 128
 129 void nfsd_fault_inject_cleanup(void)
 130 {
 131         debugfs_remove_recursive(debug_dir);
 132 }
 133
 134 static struct nfsd_fault_inject_op inject_ops[] = {
 135         {
 136                 .file     = "forget_clients",
 137                 .get      = nfsd_inject_print_clients,
 138                 .set_val  = nfsd_inject_set,
 139                 .set_clnt = nfsd_inject_forget_client,
 140                 .forget   = nfsd_forget_client,
 141         },
 142         {
 143                 .file     = "forget_locks",
 144                 .get      = nfsd_inject_get,
 145                 .set_val  = nfsd_inject_set,
 146                 .set_clnt = nfsd_inject_set_client,
 147                 .forget   = nfsd_forget_client_locks,
 148                 .print    = nfsd_print_client_locks,
 149         },
 150         {
 151                 .file     = "forget_openowners",
 152                 .get      = nfsd_inject_get,
 153                 .set_val  = nfsd_inject_set,
 154                 .set_clnt = nfsd_inject_set_client,
 155                 .forget   = nfsd_forget_client_openowners,
 156                 .print    = nfsd_print_client_openowners,
 157         },
 158         {
 159                 .file     = "forget_delegations",
 160                 .get      = nfsd_inject_get,
 161                 .set_val  = nfsd_inject_set,
 162                 .set_clnt = nfsd_inject_set_client,
 163                 .forget   = nfsd_forget_client_delegations,
 164                 .print    = nfsd_print_client_delegations,
 165         },
 166         {
 167                 .file     = "recall_delegations",
 168                 .get      = nfsd_inject_get,
 169                 .set_val  = nfsd_inject_set,
 170                 .set_clnt = nfsd_inject_set_client,
 171                 .forget   = nfsd_recall_client_delegations,
 172                 .print    = nfsd_print_client_delegations,
 173         },
 174 };
 175
 176 #define NUM_INJECT_OPS (sizeof(inject_ops)/sizeof(struct nfsd_fault_inject_op))
 177
 178 int nfsd_fault_inject_init(void)
 179 {
 180         unsigned int i;
 181         struct nfsd_fault_inject_op *op;
 182         umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
 183
 184         debug_dir = debugfs_create_dir("nfsd", NULL);
 185         if (!debug_dir)
 186                 goto fail;
 187
 188         for (i = 0; i < NUM_INJECT_OPS; i++) {
 189                 op = &inject_ops[i];
 190                 if (!debugfs_create_file(op->file, mode, debug_dir, op, &fops_nfsd))
 191                         goto fail;
 192         }
 193         return 0;
 194
 195 fail:
 196         nfsd_fault_inject_cleanup();
 197         return -ENOMEM;
 198 }