mapfile.c

   1 /*
   2  * mapfile - manage /var/run/mdadm.map. Part of:
   3  * mdadm - manage Linux "md" devices aka RAID arrays.
   4  *
   5  * Copyright (C) 2006 Neil Brown <neilb@suse.de>
   6  *
   7  *
   8  *    This program is free software; you can redistribute it and/or modify
   9  *    it under the terms of the GNU General Public License as published by
  10  *    the Free Software Foundation; either version 2 of the License, or
  11  *    (at your option) any later version.
  12  *
  13  *    This program is distributed in the hope that it will be useful,
  14  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *    GNU General Public License for more details.
  17  *
  18  *    You should have received a copy of the GNU General Public License
  19  *    along with this program; if not, write to the Free Software
  20  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  *    Author: Neil Brown
  23  *    Email: <neilb@suse.de>
  24  *    Paper: Neil Brown
  25  *           Novell Inc
  26  *           GPO Box Q1283
  27  *           QVB Post Office, NSW 1230
  28  *           Australia
  29  */
  30
  31 /* /var/run/mdadm.map is used to track arrays being created in --incremental
  32  * more.  It particularly allows lookup from UUID to array device, but
  33  * also allows the array device name to be easily found.
  34  *
  35  * The map file is line based with space separated fields.  The fields are:
  36  *  Device id  -  mdX or mdpX  where X is a number.
  37  *  metadata   -  0.90 1.0 1.1 1.2 ddf ...
  38  *  UUID       -  uuid of the array
  39  *  path       -  path where device created: /dev/md/home
  40  *
  41  */
  42
  43
  44 #include "mdadm.h"
  45
  46
  47 int map_write(struct map_ent *mel)
  48 {
  49         FILE *f;
  50         int err;
  51         int subdir = 1;
  52
  53         f = fopen("/var/run/mdadm/map.new", "w");
  54         if (!f) {
  55                 f = fopen("/var/run/mdadm.map.new", "w");
  56                 subdir = 1;
  57         }
  58         if (!f)
  59                 return 0;
  60         while (mel) {
  61                 if (mel->devnum < 0)
  62                         fprintf(f, "mdp%d ", -1-mel->devnum);
  63                 else
  64                         fprintf(f, "md%d ", mel->devnum);
  65                 fprintf(f, "%s ", mel->metadata);
  66                 fprintf(f, "%08x:%08x:%08x:%08x ", mel->uuid[0],
  67                         mel->uuid[1], mel->uuid[2], mel->uuid[3]);
  68                 fprintf(f, "%s\n", mel->path);
  69                 mel = mel->next;
  70         }
  71         fflush(f);
  72         err = ferror(f);
  73         fclose(f);
  74         if (err) {
  75                 if (subdir)
  76                         unlink("/var/run/mdadm/map.new");
  77                 else
  78                         unlink("/var/run/mdadm.map.new");
  79                 return 0;
  80         }
  81         if (subdir)
  82                 return rename("/var/run/mdadm/map.new",
  83                               "/var/run/mdadm/map") == 0;
  84         else
  85                 return rename("/var/run/mdadm.map.new",
  86                               "/var/run/mdadm.map") == 0;
  87 }
  88
  89 void map_add(struct map_ent **melp,
  90             int devnum, char *metadata, int uuid[4], char *path)
  91 {
  92         struct map_ent *me = malloc(sizeof(*me));
  93
  94         me->devnum = devnum;
  95         strcpy(me->metadata, metadata);
  96         memcpy(me->uuid, uuid, 16);
  97         me->path = strdup(path);
  98         me->next = *melp;
  99         *melp = me;
 100 }
 101
 102 void map_read(struct map_ent **melp)
 103 {
 104         FILE *f;
 105         char buf[8192];
 106         char path[200];
 107         int devnum, uuid[4];
 108         char metadata[30];
 109         char nam[4];
 110
 111         *melp = NULL;
 112
 113         f = fopen("/var/run/mdadm/map", "r");
 114         if (!f)
 115                 f = fopen("/var/run/mdadm.map", "r");
 116         if (!f)
 117                 return;
 118
 119         while (fgets(buf, sizeof(buf), f)) {
 120                 if (sscanf(buf, " %3[mdp]%d %s %x:%x:%x:%x %200s",
 121                            nam, &devnum, metadata, uuid, uuid+1,
 122                            uuid+2, uuid+3, path) == 8) {
 123                         if (strncmp(nam, "md", 2) != 0)
 124                                 continue;
 125                         if (nam[2] == 'p')
 126                                 devnum = -1 - devnum;
 127                         map_add(melp, devnum, metadata, uuid, path);
 128                 }
 129         }
 130         fclose(f);
 131 }
 132
 133 void map_free(struct map_ent *map)
 134 {
 135         while (map) {
 136                 struct map_ent *mp = map;
 137                 map = mp->next;
 138                 free(mp->path);
 139                 free(mp);
 140         }
 141 }
 142
 143 int map_update(struct map_ent **mpp, int devnum, char *metadata,
 144                int *uuid, char *path)
 145 {
 146         struct map_ent *map, *mp;
 147         int rv;
 148
 149         if (mpp && *mpp)
 150                 map = *mpp;
 151         else
 152                 map_read(&map);
 153
 154         for (mp = map ; mp ; mp=mp->next)
 155                 if (mp->devnum == devnum) {
 156                         strcpy(mp->metadata, metadata);
 157                         memcpy(mp->uuid, uuid, 16);
 158                         free(mp->path);
 159                         mp->path = strdup(path);
 160                         break;
 161                 }
 162         if (!mp)
 163                 map_add(&map, devnum, metadata, uuid, path);
 164         *mpp = NULL;
 165         rv = map_write(map);
 166         map_free(map);
 167         return rv;
 168 }
 169
 170 void map_delete(struct map_ent **mapp, int devnum)
 171 {
 172         struct map_ent *mp;
 173
 174         if (*mapp == NULL)
 175                 map_read(mapp);
 176
 177         for (mp = *mapp; mp; mp = *mapp) {
 178                 if (mp->devnum == devnum) {
 179                         *mapp = mp->next;
 180                         free(mp->path);
 181                         free(mp);
 182                 } else
 183                         mapp = & mp->next;
 184         }
 185 }
 186
 187 struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
 188 {
 189         struct map_ent *mp;
 190         if (!*map)
 191                 map_read(map);
 192
 193         for (mp = *map ; mp ; mp = mp->next)
 194                 if (memcmp(uuid, mp->uuid, 16) == 0)
 195                         return mp;
 196         return NULL;
 197
 198 }