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                 c->namelen = strlen(c->name);
  58                 bucket = jhash(c->name, c->namelen, 0) % ERRHASHSZ;
  59                 INIT_HLIST_NODE(&c->list);
  60                 hlist_add_head(&c->list, &hash_errmap[bucket]);
  61         }
  62
  63         return 1;
  64 }
  65
  66 /**
  67  * errstr2errno - convert error string to error number
  68  * @errstr: error string
  69  *
  70  */
  71
  72 int v9fs_errstr2errno(char *errstr, int len)
  73 {
  74         int errno = 0;
  75         struct hlist_node *p = NULL;
  76         struct errormap *c = NULL;
  77         int bucket = jhash(errstr, len, 0) % ERRHASHSZ;
  78
  79         hlist_for_each_entry(c, p, &hash_errmap[bucket], list) {
  80                 if (c->namelen==len && !memcmp(c->name, errstr, len)) {
  81                         errno = c->val;
  82                         break;
  83                 }
  84         }
  85
  86         if (errno == 0) {
  87                 /* TODO: if error isn't found, add it dynamically */
  88                 printk(KERN_ERR "%s: errstr :%s: not found\n", __FUNCTION__,
  89                        errstr);
  90                 errno = 1;
  91         }
  92
  93         return -errno;
  94 }