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