net/sunrpc/sysctl.c

   1 /*
   2  * linux/net/sunrpc/sysctl.c
   3  *
   4  * Sysctl interface to sunrpc module. This is for debugging only now.
   5  *
   6  * I would prefer to register the sunrpc table below sys/net, but that's
   7  * impossible at the moment.
   8  */
   9
  10 #include <linux/config.h>
  11 #include <linux/version.h>
  12 #include <linux/types.h>
  13 #include <linux/linkage.h>
  14 #include <linux/ctype.h>
  15 #include <linux/fs.h>
  16 #include <linux/sysctl.h>
  17 #include <linux/module.h>
  18
  19 #include <asm/uaccess.h>
  20 #include <linux/sunrpc/types.h>
  21 #include <linux/sunrpc/sched.h>
  22 #include <linux/sunrpc/stats.h>
  23
  24 /*
  25  * Declare the debug flags here
  26  */
  27 unsigned int    rpc_debug;
  28 unsigned int    nfs_debug;
  29 unsigned int    nfsd_debug;
  30 unsigned int    nlm_debug;
  31
  32 #ifdef RPC_DEBUG
  33
  34 static struct ctl_table_header *sunrpc_table_header;
  35 static ctl_table                sunrpc_table[];
  36
  37 void
  38 rpc_register_sysctl(void)
  39 {
  40         if (!sunrpc_table_header) {
  41                 sunrpc_table_header = register_sysctl_table(sunrpc_table, 1);
  42 #ifdef CONFIG_PROC_FS
  43                 if (sunrpc_table[0].de)
  44                         sunrpc_table[0].de->owner = THIS_MODULE;
  45 #endif
  46         }
  47
  48 }
  49
  50 void
  51 rpc_unregister_sysctl(void)
  52 {
  53         if (sunrpc_table_header) {
  54                 unregister_sysctl_table(sunrpc_table_header);
  55                 sunrpc_table_header = NULL;
  56         }
  57 }
  58
  59 static int
  60 proc_dodebug(ctl_table *table, int write, struct file *file,
  61                                 void *buffer, size_t *lenp)
  62 {
  63         char            tmpbuf[20], *p, c;
  64         unsigned int    value;
  65         size_t          left, len;
  66
  67         if ((file->f_pos && !write) || !*lenp) {
  68                 *lenp = 0;
  69                 return 0;
  70         }
  71
  72         left = *lenp;
  73
  74         if (write) {
  75                 if (!access_ok(VERIFY_READ, buffer, left))
  76                         return -EFAULT;
  77                 p = (char *) buffer;
  78                 while (left && __get_user(c, p) >= 0 && isspace(c))
  79                         left--, p++;
  80                 if (!left)
  81                         goto done;
  82
  83                 if (left > sizeof(tmpbuf) - 1)
  84                         return -EINVAL;
  85                 copy_from_user(tmpbuf, p, left);
  86                 tmpbuf[left] = '\0';
  87
  88                 for (p = tmpbuf, value = 0; '0' <= *p && *p <= '9'; p++, left--)
  89                         value = 10 * value + (*p - '0');
  90                 if (*p && !isspace(*p))
  91                         return -EINVAL;
  92                 while (left && isspace(*p))
  93                         left--, p++;
  94                 *(unsigned int *) table->data = value;
  95                 /* Display the RPC tasks on writing to rpc_debug */
  96                 if (table->ctl_name == CTL_RPCDEBUG) {
  97                         rpc_show_tasks();
  98                 }
  99         } else {
 100                 if (!access_ok(VERIFY_WRITE, buffer, left))
 101                         return -EFAULT;
 102                 len = sprintf(tmpbuf, "%d", *(unsigned int *) table->data);
 103                 if (len > left)
 104                         len = left;
 105                 copy_to_user(buffer, tmpbuf, len);
 106                 if ((left -= len) > 0) {
 107                         put_user('\n', (char *)buffer + len);
 108                         left--;
 109                 }
 110         }
 111
 112 done:
 113         *lenp -= left;
 114         file->f_pos += *lenp;
 115         return 0;
 116 }
 117
 118 #define DIRENTRY(nam1, nam2, child)     \
 119         {CTL_##nam1, #nam2, NULL, 0, 0555, child }
 120 #define DBGENTRY(nam1, nam2)    \
 121         {CTL_##nam1##DEBUG, #nam2 "_debug", &nam2##_debug, sizeof(int),\
 122          0644, NULL, &proc_dodebug}
 123
 124 static ctl_table                debug_table[] = {
 125         DBGENTRY(RPC,  rpc),
 126         DBGENTRY(NFS,  nfs),
 127         DBGENTRY(NFSD, nfsd),
 128         DBGENTRY(NLM,  nlm),
 129         {0}
 130 };
 131
 132 static ctl_table                sunrpc_table[] = {
 133         DIRENTRY(SUNRPC, sunrpc, debug_table),
 134         {0}
 135 };
 136
 137 #endif