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 = 0;
  57         }
  58         if (!f)
  59                 return 0;
  60         for (; mel; mel = mel->next) {
  61                 if (mel->bad)
  62                         continue;
  63                 if (mel->devnum < 0)
  64                         fprintf(f, "mdp%d ", -1-mel->devnum);
  65                 else
  66                         fprintf(f, "md%d ", mel->devnum);
  67                 fprintf(f, "%s ", mel->metadata);
  68                 fprintf(f, "%08x:%08x:%08x:%08x ", mel->uuid[0],
  69                         mel->uuid[1], mel->uuid[2], mel->uuid[3]);
  70                 fprintf(f, "%s\n", mel->path);
  71         }
  72         fflush(f);
  73         err = ferror(f);
  74         fclose(f);
  75         if (err) {
  76                 if (subdir)
  77                         unlink("/var/run/mdadm/map.new");
  78                 else
  79                         unlink("/var/run/mdadm.map.new");
  80                 return 0;
  81         }
  82         if (subdir)
  83                 return rename("/var/run/mdadm/map.new",
  84                               "/var/run/mdadm/map") == 0;
  85         else
  86                 return rename("/var/run/mdadm.map.new",
  87                               "/var/run/mdadm.map") == 0;
  88 }
  89
  90
  91 static int lfd = -1;
  92 static int lsubdir = 0;
  93 int map_lock(struct map_ent **melp)
  94 {
  95         if (lfd < 0) {
  96                 lfd = open("/var/run/mdadm/map.lock", O_CREAT|O_RDWR, 0600);
  97                 if (lfd < 0) {
  98                         lfd = open("/var/run/mdadm.map.lock", O_CREAT|O_RDWR, 0600);
  99                         lsubdir = 0;
 100                 } else
 101                         lsubdir = 1;
 102                 if (lfd < 0)
 103                         return -1;
 104                 if (lockf(lfd, F_LOCK, 0) != 0) {
 105                         close(lfd);
 106                         lfd = -1;
 107                         return -1;
 108                 }
 109         }
 110         if (*melp)
 111                 map_free(*melp);
 112         map_read(melp);
 113         return 0;
 114 }
 115
 116 void map_unlock(struct map_ent **melp)
 117 {
 118         if (lfd >= 0)
 119                 close(lfd);
 120         if (lsubdir)
 121                 unlink("/var/run/mdadm/map.lock");
 122         else
 123                 unlink("/var/run/mdadm.map.lock");
 124         lfd = -1;
 125 }
 126
 127 void map_add(struct map_ent **melp,
 128             int devnum, char *metadata, int uuid[4], char *path)
 129 {
 130         struct map_ent *me = malloc(sizeof(*me));
 131
 132         me->devnum = devnum;
 133         strcpy(me->metadata, metadata);
 134         memcpy(me->uuid, uuid, 16);
 135         me->path = strdup(path);
 136         me->next = *melp;
 137         me->bad = 0;
 138         *melp = me;
 139 }
 140
 141 void map_read(struct map_ent **melp)
 142 {
 143         FILE *f;
 144         char buf[8192];
 145         char path[200];
 146         int devnum, uuid[4];
 147         char metadata[30];
 148         char nam[4];
 149
 150         *melp = NULL;
 151
 152         f = fopen("/var/run/mdadm/map", "r");
 153         if (!f)
 154                 f = fopen("/var/run/mdadm.map", "r");
 155         if (!f)
 156                 return;
 157
 158         while (fgets(buf, sizeof(buf), f)) {
 159                 if (sscanf(buf, " %3[mdp]%d %s %x:%x:%x:%x %200s",
 160                            nam, &devnum, metadata, uuid, uuid+1,
 161                            uuid+2, uuid+3, path) == 8) {
 162                         if (strncmp(nam, "md", 2) != 0)
 163                                 continue;
 164                         if (nam[2] == 'p')
 165                                 devnum = -1 - devnum;
 166                         map_add(melp, devnum, metadata, uuid, path);
 167                 }
 168         }
 169         fclose(f);
 170 }
 171
 172 void map_free(struct map_ent *map)
 173 {
 174         while (map) {
 175                 struct map_ent *mp = map;
 176                 map = mp->next;
 177                 free(mp->path);
 178                 free(mp);
 179         }
 180 }
 181
 182 int map_update(struct map_ent **mpp, int devnum, char *metadata,
 183                int *uuid, char *path)
 184 {
 185         struct map_ent *map, *mp;
 186         int rv;
 187
 188         if (mpp && *mpp)
 189                 map = *mpp;
 190         else
 191                 map_read(&map);
 192
 193         for (mp = map ; mp ; mp=mp->next)
 194                 if (mp->devnum == devnum) {
 195                         strcpy(mp->metadata, metadata);
 196                         memcpy(mp->uuid, uuid, 16);
 197                         free(mp->path);
 198                         mp->path = strdup(path);
 199                         break;
 200                 }
 201         if (!mp)
 202                 map_add(&map, devnum, metadata, uuid, path);
 203         if (mpp)
 204                 *mpp = NULL;
 205         rv = map_write(map);
 206         map_free(map);
 207         return rv;
 208 }
 209
 210 void map_delete(struct map_ent **mapp, int devnum)
 211 {
 212         struct map_ent *mp;
 213
 214         if (*mapp == NULL)
 215                 map_read(mapp);
 216
 217         for (mp = *mapp; mp; mp = *mapp) {
 218                 if (mp->devnum == devnum) {
 219                         *mapp = mp->next;
 220                         free(mp->path);
 221                         free(mp);
 222                 } else
 223                         mapp = & mp->next;
 224         }
 225 }
 226
 227 struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
 228 {
 229         struct map_ent *mp;
 230         if (!*map)
 231                 map_read(map);
 232
 233         for (mp = *map ; mp ; mp = mp->next) {
 234                 if (memcmp(uuid, mp->uuid, 16) != 0)
 235                         continue;
 236                 if (!mddev_busy(mp->devnum)) {
 237                         mp->bad = 1;
 238                         continue;
 239                 }
 240                 return mp;
 241         }
 242         return NULL;
 243 }
 244
 245 struct map_ent *map_by_devnum(struct map_ent **map, int devnum)
 246 {
 247         struct map_ent *mp;
 248         if (!*map)
 249                 map_read(map);
 250
 251         for (mp = *map ; mp ; mp = mp->next) {
 252                 if (mp->devnum != devnum)
 253                         continue;
 254                 if (!mddev_busy(mp->devnum)) {
 255                         mp->bad = 1;
 256                         continue;
 257                 }
 258                 return mp;
 259         }
 260         return NULL;
 261 }
 262
 263 struct map_ent *map_by_name(struct map_ent **map, char *name)
 264 {
 265         struct map_ent *mp;
 266         if (!*map)
 267                 map_read(map);
 268
 269         for (mp = *map ; mp ; mp = mp->next) {
 270                 if (strncmp(mp->path, "/dev/md/", 8) != 0)
 271                         continue;
 272                 if (strcmp(mp->path+8, name) != 0)
 273                         continue;
 274                 if (!mddev_busy(mp->devnum)) {
 275                         mp->bad = 1;
 276                         continue;
 277                 }
 278                 return mp;
 279         }
 280         return NULL;
 281 }