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 version 2
  15  *  as published by the Free Software Foundation.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to:
  24  *  Free Software Foundation
  25  *  51 Franklin Street, Fifth Floor
  26  *  Boston, MA  02111-1301  USA
  27  *
  28  */
  29
  30 #include <linux/module.h>
  31
  32 #include <linux/list.h>
  33 #include <linux/jhash.h>
  34
  35 #include "debug.h"
  36 #include "error.h"
  37
  38 /**
  39  * v9fs_error_init - preload
  40  * @errstr: error string
  41  *
  42  */
  43
  44 int v9fs_error_init(void)
  45 {
  46         struct errormap *c;
  47         int bucket;
  48
  49         /* initialize hash table */
  50         for (bucket = 0; bucket < ERRHASHSZ; bucket++)
  51                 INIT_HLIST_HEAD(&hash_errmap[bucket]);
  52
  53         /* load initial error map into hash table */
  54         for (c = errmap; c->name != NULL; c++) {
  55                 c->namelen = strlen(c->name);
  56                 bucket = jhash(c->name, c->namelen, 0) % ERRHASHSZ;
  57                 INIT_HLIST_NODE(&c->list);
  58                 hlist_add_head(&c->list, &hash_errmap[bucket]);
  59         }
  60
  61         return 1;
  62 }
  63
  64 /**
  65  * errstr2errno - convert error string to error number
  66  * @errstr: error string
  67  *
  68  */
  69
  70 int v9fs_errstr2errno(char *errstr, int len)
  71 {
  72         int errno = 0;
  73         struct hlist_node *p = NULL;
  74         struct errormap *c = NULL;
  75         int bucket = jhash(errstr, len, 0) % ERRHASHSZ;
  76
  77         hlist_for_each_entry(c, p, &hash_errmap[bucket], list) {
  78                 if (c->namelen==len && !memcmp(c->name, errstr, len)) {
  79                         errno = c->val;
  80                         break;
  81                 }
  82         }
  83
  84         if (errno == 0) {
  85                 /* TODO: if error isn't found, add it dynamically */
  86                 errstr[len] = 0;
  87                 printk(KERN_ERR "%s: errstr :%s: not found\n", __FUNCTION__,
  88                        errstr);
  89                 errno = 1;
  90         }
  91
  92         return -errno;
  93 }