sysfs.c

   1 /*
   2  * sysfs - extract md related information from sysfs.  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  */
  25
  26 #include        "mdadm.h"
  27 #include        <dirent.h>
  28
  29 int load_sys(char *path, char *buf)
  30 {
  31         int fd = open(path, O_RDONLY);
  32         int n;
  33         if (fd < 0)
  34                 return -1;
  35         n = read(fd, buf, 1024);
  36         close(fd);
  37         if (n <0 || n >= 1024)
  38                 return -1;
  39         buf[n] = 0;
  40         if (buf[n-1] == '\n')
  41                 buf[n-1] = 0;
  42         return 0;
  43 }
  44
  45 void sysfs_free(struct mdinfo *sra)
  46 {
  47         while (sra) {
  48                 struct mdinfo *sra2 = sra->next;
  49                 while (sra->devs) {
  50                         struct mdinfo *d = sra->devs;
  51                         sra->devs = d->next;
  52                         free(d);
  53                 }
  54                 free(sra);
  55                 sra = sra2;
  56         }
  57 }
  58
  59 int sysfs_open(int devnum, char *devname, char *attr)
  60 {
  61         char fname[50];
  62         char sys_name[16];
  63         int fd;
  64         if (devnum >= 0)
  65                 sprintf(sys_name, "md%d", devnum);
  66         else
  67                 sprintf(sys_name, "md_d%d",
  68                         -1-devnum);
  69
  70         sprintf(fname, "/sys/block/%s/md/", sys_name);
  71         if (devname) {
  72                 strcat(fname, devname);
  73                 strcat(fname, "/");
  74         }
  75         strcat(fname, attr);
  76         fd = open(fname, O_RDWR);
  77         if (fd < 0 && errno == -EACCES)
  78                 fd = open(fname, O_RDONLY);
  79         return fd;
  80 }
  81
  82 struct mdinfo *sysfs_read(int fd, int devnum, unsigned long options)
  83 {
  84         /* Longest possible name in sysfs, mounted at /sys, is
  85          *  /sys/block/md_dXXX/md/dev-XXXXX/block/dev
  86          *  /sys/block/md_dXXX/md/metadata_version
  87          * which is about 41 characters.  50 should do for now
  88          */
  89         char fname[50];
  90         char buf[1024];
  91         char *base;
  92         char *dbase;
  93         struct mdinfo *sra;
  94         struct mdinfo *dev;
  95         DIR *dir;
  96         struct dirent *de;
  97
  98         sra = malloc(sizeof(*sra));
  99         if (sra == NULL)
 100                 return sra;
 101         sra->next = NULL;
 102
 103         if (fd >= 0) {
 104                 struct stat stb;
 105                 mdu_version_t vers;
 106                 if (fstat(fd, &stb)) return NULL;
 107                 if (ioctl(fd, RAID_VERSION, &vers) != 0)
 108                         return NULL;
 109                 if (major(stb.st_rdev)==9)
 110                         sprintf(sra->sys_name, "md%d", (int)minor(stb.st_rdev));
 111                 else
 112                         sprintf(sra->sys_name, "md_d%d",
 113                                 (int)minor(stb.st_rdev)>>MdpMinorShift);
 114         } else {
 115                 if (devnum >= 0)
 116                         sprintf(sra->sys_name, "md%d", devnum);
 117                 else
 118                         sprintf(sra->sys_name, "md_d%d",
 119                                 -1-devnum);
 120         }
 121         sprintf(fname, "/sys/block/%s/md/", sra->sys_name);
 122         base = fname + strlen(fname);
 123
 124         sra->devs = NULL;
 125         if (options & GET_VERSION) {
 126                 strcpy(base, "metadata_version");
 127                 if (load_sys(fname, buf))
 128                         goto abort;
 129                 if (strncmp(buf, "none", 4) == 0) {
 130                         sra->array.major_version =
 131                                 sra->array.minor_version = -1;
 132                         strcpy(sra->text_version, "");
 133                 } else if (strncmp(buf, "external:", 9) == 0) {
 134                         sra->array.major_version = -1;
 135                         sra->array.minor_version = -2;
 136                         strcpy(sra->text_version, buf+9);
 137                 } else
 138                         sscanf(buf, "%d.%d",
 139                                &sra->array.major_version,
 140                                &sra->array.minor_version);
 141         }
 142         if (options & GET_LEVEL) {
 143                 strcpy(base, "level");
 144                 if (load_sys(fname, buf))
 145                         goto abort;
 146                 sra->array.level = map_name(pers, buf);
 147         }
 148         if (options & GET_LAYOUT) {
 149                 strcpy(base, "layout");
 150                 if (load_sys(fname, buf))
 151                         goto abort;
 152                 sra->array.layout = strtoul(buf, NULL, 0);
 153         }
 154         if (options & GET_DISKS) {
 155                 strcpy(base, "raid_disks");
 156                 if (load_sys(fname, buf))
 157                         goto abort;
 158                 sra->array.raid_disks = strtoul(buf, NULL, 0);
 159         }
 160         if (options & GET_COMPONENT) {
 161                 strcpy(base, "component_size");
 162                 if (load_sys(fname, buf))
 163                         goto abort;
 164                 sra->component_size = strtoull(buf, NULL, 0);
 165                 /* sysfs reports "K", but we want sectors */
 166                 sra->component_size *= 2;
 167         }
 168         if (options & GET_CHUNK) {
 169                 strcpy(base, "chunk_size");
 170                 if (load_sys(fname, buf))
 171                         goto abort;
 172                 sra->array.chunk_size = strtoul(buf, NULL, 0);
 173         }
 174         if (options & GET_CACHE) {
 175                 strcpy(base, "stripe_cache_size");
 176                 if (load_sys(fname, buf))
 177                         goto abort;
 178                 sra->cache_size = strtoul(buf, NULL, 0);
 179         }
 180         if (options & GET_MISMATCH) {
 181                 strcpy(base, "mismatch_cnt");
 182                 if (load_sys(fname, buf))
 183                         goto abort;
 184                 sra->mismatch_cnt = strtoul(buf, NULL, 0);
 185         }
 186
 187         if (! (options & GET_DEVS))
 188                 return sra;
 189
 190         /* Get all the devices as well */
 191         *base = 0;
 192         dir = opendir(fname);
 193         if (!dir)
 194                 goto abort;
 195         sra->array.spare_disks = 0;
 196
 197         while ((de = readdir(dir)) != NULL) {
 198                 char *ep;
 199                 if (de->d_ino == 0 ||
 200                     strncmp(de->d_name, "dev-", 4) != 0)
 201                         continue;
 202                 strcpy(base, de->d_name);
 203                 dbase = base + strlen(base);
 204                 *dbase++ = '/';
 205
 206                 dev = malloc(sizeof(*dev));
 207                 if (!dev)
 208                         goto abort;
 209                 dev->next = sra->devs;
 210                 sra->devs = dev;
 211                 strcpy(dev->sys_name, de->d_name);
 212
 213                 /* Always get slot, major, minor */
 214                 strcpy(dbase, "slot");
 215                 if (load_sys(fname, buf))
 216                         goto abort;
 217                 dev->disk.raid_disk = strtoul(buf, &ep, 10);
 218                 if (*ep) dev->disk.raid_disk = -1;
 219
 220                 strcpy(dbase, "block/dev");
 221                 if (load_sys(fname, buf))
 222                         goto abort;
 223                 sscanf(buf, "%d:%d", &dev->disk.major, &dev->disk.minor);
 224
 225                 if (options & GET_OFFSET) {
 226                         strcpy(dbase, "offset");
 227                         if (load_sys(fname, buf))
 228                                 goto abort;
 229                         dev->data_offset = strtoull(buf, NULL, 0);
 230                 }
 231                 if (options & GET_SIZE) {
 232                         strcpy(dbase, "size");
 233                         if (load_sys(fname, buf))
 234                                 goto abort;
 235                         dev->component_size = strtoull(buf, NULL, 0);
 236                 }
 237                 if (options & GET_STATE) {
 238                         dev->disk.state = 0;
 239                         strcpy(dbase, "state");
 240                         if (load_sys(fname, buf))
 241                                 goto abort;
 242                         if (strstr(buf, "in_sync"))
 243                                 dev->disk.state |= (1<<MD_DISK_SYNC);
 244                         if (strstr(buf, "faulty"))
 245                                 dev->disk.state |= (1<<MD_DISK_FAULTY);
 246                         if (dev->disk.state == 0)
 247                                 sra->array.spare_disks++;
 248                 }
 249                 if (options & GET_ERROR) {
 250                         strcpy(buf, "errors");
 251                         if (load_sys(fname, buf))
 252                                 goto abort;
 253                         dev->errors = strtoul(buf, NULL, 0);
 254                 }
 255         }
 256         return sra;
 257
 258  abort:
 259         sysfs_free(sra);
 260         return NULL;
 261 }
 262
 263 unsigned long long get_component_size(int fd)
 264 {
 265         /* Find out the component size of the array.
 266          * We cannot trust GET_ARRAY_INFO ioctl as it's
 267          * size field is only 32bits.
 268          * So look in /sys/block/mdXXX/md/component_size
 269          *
 270          * This returns in units of sectors.
 271          */
 272         struct stat stb;
 273         char fname[50];
 274         int n;
 275         if (fstat(fd, &stb)) return 0;
 276         if (major(stb.st_rdev) == 9)
 277                 sprintf(fname, "/sys/block/md%d/md/component_size",
 278                         (int)minor(stb.st_rdev));
 279         else
 280                 sprintf(fname, "/sys/block/md_d%d/md/component_size",
 281                         (int)minor(stb.st_rdev)>>MdpMinorShift);
 282         fd = open(fname, O_RDONLY);
 283         if (fd < 0)
 284                 return 0;
 285         n = read(fd, fname, sizeof(fname));
 286         close(fd);
 287         if (n == sizeof(fname))
 288                 return 0;
 289         fname[n] = 0;
 290         return strtoull(fname, NULL, 10) * 2;
 291 }
 292
 293 int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
 294                   char *name, char *val)
 295 {
 296         char fname[50];
 297         int n;
 298         int fd;
 299         sprintf(fname, "/sys/block/%s/md/%s/%s",
 300                 sra->sys_name, dev?dev->sys_name:"", name);
 301         fd = open(fname, O_WRONLY);
 302         if (fd < 0)
 303                 return -1;
 304         n = write(fd, val, strlen(val));
 305         close(fd);
 306         if (n != strlen(val))
 307                 return -1;
 308         return 0;
 309 }
 310
 311 int sysfs_set_num(struct mdinfo *sra, struct mdinfo *dev,
 312                   char *name, unsigned long long val)
 313 {
 314         char valstr[50];
 315         sprintf(valstr, "%llu", val);
 316         return sysfs_set_str(sra, dev, name, valstr);
 317 }
 318
 319 int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
 320                        char *name, unsigned long long *val)
 321 {
 322         char fname[50];
 323         char buf[50];
 324         int n;
 325         int fd;
 326         char *ep;
 327         sprintf(fname, "/sys/block/%s/md/%s/%s",
 328                 sra->sys_name, dev?dev->sys_name:"", name);
 329         fd = open(fname, O_RDONLY);
 330         if (fd < 0)
 331                 return -1;
 332         n = read(fd, buf, sizeof(buf));
 333         close(fd);
 334         if (n <= 0)
 335                 return -1;
 336         buf[n] = 0;
 337         *val = strtoull(buf, &ep, 0);
 338         if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
 339                 return -1;
 340         return 0;
 341 }
 342
 343 int sysfs_set_array(struct mdinfo *sra,
 344                     struct mdinfo *info)
 345 {
 346         int rv = 0;
 347         sra->array = info->array;
 348
 349         if (info->array.level < 0)
 350                 return 0; /* FIXME */
 351         rv |= sysfs_set_str(sra, NULL, "level",
 352                             map_num(pers, info->array.level));
 353         rv |= sysfs_set_num(sra, NULL, "raid_disks", info->array.raid_disks);
 354         rv |= sysfs_set_num(sra, NULL, "chunk_size", info->array.chunk_size);
 355         rv |= sysfs_set_num(sra, NULL, "layout", info->array.layout);
 356         rv |= sysfs_set_num(sra, NULL, "component_size", info->component_size);
 357         rv |= sysfs_set_num(sra, NULL, "resync_start", info->resync_start);
 358         sra->array = info->array;
 359         return rv;
 360 }
 361
 362 int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd)
 363 {
 364         char dv[100];
 365         char nm[100];
 366         struct mdinfo *sd2;
 367         char *dname;
 368         int rv;
 369
 370         sprintf(dv, "%d:%d", sd->disk.major, sd->disk.minor);
 371         rv = sysfs_set_str(sra, NULL, "new_dev", dv);
 372         if (rv)
 373                 return rv;
 374
 375         memset(nm, 0, sizeof(nm));
 376         sprintf(dv, "/sys/dev/block/%d:%d", sd->disk.major, sd->disk.minor);
 377         if (readlink(dv, nm, sizeof(nm)) < 0)
 378                 return -1;
 379         dname = strrchr(nm, '/');
 380         if (dname) dname++;
 381         strcpy(sd->sys_name, "dev-");
 382         strcpy(sd->sys_name+4, dname);
 383
 384         rv |= sysfs_set_num(sra, sd, "offset", sd->data_offset);
 385         rv |= sysfs_set_num(sra, sd, "size", (sd->component_size+1) / 2);
 386         if (sra->array.level != LEVEL_CONTAINER) {
 387                 rv |= sysfs_set_num(sra, sd, "slot", sd->disk.raid_disk);
 388 //              rv |= sysfs_set_str(sra, sd, "state", "in_sync");
 389         }
 390         sd2 = malloc(sizeof(*sd2));
 391         *sd2 = *sd;
 392         sd2->next = sra->devs;
 393         sra->devs = sd2;
 394
 395         return rv;
 396 }