fs/9p/error.c

   1 /*
   2  * linux/fs/9p/error.c
   3  *
   4  * Error string handling
   5  *
   6  * Plan 9 uses error strings, Unix uses error numbers.  These functions
   7  * try to help manage that and provide for dynamically adding error
   8  * mappings.
   9  *
  10  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
  11  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License as published by
  15  *  the Free Software Foundation; either version 2 of the License, or
  16  *  (at your option) any later version.
  17  *
  18  *  This program is distributed in the hope that it will be useful,
  19  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  *  GNU General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License
  24  *  along with this program; if not, write to:
  25  *  Free Software Foundation
  26  *  51 Franklin Street, Fifth Floor
  27  *  Boston, MA  02111-1301  USA
  28  *
  29  */
  30
  31 #include <linux/config.h>
  32 #include <linux/module.h>
  33
  34 #include <linux/list.h>
  35 #include <linux/jhash.h>
  36
  37 #include "debug.h"
  38 #include "error.h"
  39
  40 /**
  41  * v9fs_error_init - preload
  42  * @errstr: error string
  43  *
  44  */
  45
  46 int v9fs_error_init(void)
  47 {
  48         struct errormap *c;
  49         int bucket;
  50
  51         /* initialize hash table */
  52         for (bucket = 0; bucket < ERRHASHSZ; bucket++)
  53                 INIT_HLIST_HEAD(&hash_errmap[bucket]);
  54
  55         /* load initial error map into hash table */
  56         for (c = errmap; c->name != NULL; c++) {
  57                 bucket = jhash(c->name, strlen(c->name), 0) % ERRHASHSZ;
  58                 INIT_HLIST_NODE(&c->list);
  59                 hlist_add_head(&c->list, &hash_errmap[bucket]);
  60         }
  61
  62         return 1;
  63 }
  64
  65 /**
  66  * errstr2errno - convert error string to error number
  67  * @errstr: error string
  68  *
  69  */
  70
  71 int v9fs_errstr2errno(char *errstr)
  72 {
  73         int errno = 0;
  74         struct hlist_node *p = NULL;
  75         struct errormap *c = NULL;
  76         int bucket = jhash(errstr, strlen(errstr), 0) % ERRHASHSZ;
  77
  78         hlist_for_each_entry(c, p, &hash_errmap[bucket], list) {
  79                 if (!strcmp(c->name, errstr)) {
  80                         errno = c->val;
  81                         break;
  82                 }
  83         }
  84
  85         if (errno == 0) {
  86                 /* TODO: if error isn't found, add it dynamically */
  87                 printk(KERN_ERR "%s: errstr :%s: not found\n", __FUNCTION__,
  88                        errstr);
  89                 errno = 1;
  90         }
  91
  92         return -errno;
  93 }