mount.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 #include <errno.h>
   4 #include <stdio.h>
   5 #include <mntent.h>
   6
   7 #include "unit.h"
   8 #include "mount.h"
   9 #include "load-fragment.h"
  10 #include "load-fstab.h"
  11 #include "load-dropin.h"
  12 #include "log.h"
  13
  14 static int mount_init(Unit *u) {
  15         int r;
  16         Mount *m = MOUNT(u);
  17
  18         assert(m);
  19
  20         /* Load a .mount file */
  21         if ((r = unit_load_fragment(u)) < 0)
  22                 return r;
  23
  24         /* Load entry from /etc/fstab */
  25         if ((r = unit_load_fstab(u)) < 0)
  26                 return r;
  27
  28         /* Load drop-in directory data */
  29         if ((r = unit_load_dropin(u)) < 0)
  30                 return r;
  31
  32         return r;
  33 }
  34
  35 static void mount_done(Unit *u) {
  36         Mount *d = MOUNT(u);
  37
  38         assert(d);
  39         free(d->what);
  40         free(d->where);
  41 }
  42
  43 static void mount_dump(Unit *u, FILE *f, const char *prefix) {
  44
  45         static const char* const state_table[_MOUNT_STATE_MAX] = {
  46                 [MOUNT_DEAD] = "dead",
  47                 [MOUNT_MOUNTING] = "mounting",
  48                 [MOUNT_MOUNTED] = "mounted",
  49                 [MOUNT_UNMOUNTING] = "unmounting",
  50                 [MOUNT_MAINTAINANCE] = "maintainance"
  51         };
  52
  53         Mount *s = MOUNT(u);
  54
  55         assert(s);
  56
  57         fprintf(f,
  58                 "%sMount State: %s\n"
  59                 "%sWhere: %s\n"
  60                 "%sWhat: %s\n",
  61                 prefix, state_table[s->state],
  62                 prefix, s->where,
  63                 prefix, s->what);
  64 }
  65
  66 static void mount_shutdown(Manager *m) {
  67 }
  68
  69 static int mount_add_node_links(Mount *m) {
  70         Unit *device;
  71         char *e;
  72         int r;
  73
  74         assert(m);
  75
  76         /* Adds in links to the device that this node is based on */
  77
  78         if (!path_startswith(m->what, "/dev/"))
  79                 return 0;
  80
  81         if (!(e = unit_name_escape_path("node-", m->what+1, ".device")))
  82                 return -ENOMEM;
  83
  84         r = manager_load_unit(UNIT(m)->meta.manager, e, &device);
  85         free(e);
  86
  87         if (r < 0)
  88                 return r;
  89
  90         if ((r = unit_add_dependency(UNIT(m), UNIT_AFTER, device)) < 0)
  91                 return r;
  92
  93         if ((r = unit_add_dependency(UNIT(m), UNIT_REQUIRES, device)) < 0)
  94                 return r;
  95
  96         if ((r = unit_add_dependency(device, UNIT_WANTS, UNIT(m))) < 0)
  97                 return r;
  98
  99         return 0;
 100 }
 101
 102 static int mount_add_path_links(Mount *m) {
 103         Iterator i;
 104         Unit *other;
 105         int r;
 106
 107         /* Adds in link to other mount points, that might lie below or
 108          * above us in the hierarchy */
 109
 110         HASHMAP_FOREACH(other, UNIT(m)->meta.manager->units, i) {
 111                 Mount *n;
 112
 113                 if (other->meta.type != UNIT_MOUNT)
 114                         continue;
 115
 116                 n = MOUNT(other);
 117
 118                 if (path_startswith(m->where, n->where)) {
 119
 120                         if ((r = unit_add_dependency(UNIT(m), UNIT_AFTER, other)) < 0)
 121                                 return r;
 122
 123                         if ((r = unit_add_dependency(UNIT(m), UNIT_REQUIRES, other)) < 0)
 124                                 return r;
 125
 126                 } else if (startswith(n->where, m->where)) {
 127
 128                         if ((r = unit_add_dependency(UNIT(m), UNIT_BEFORE, other)) < 0)
 129                                 return r;
 130
 131                         if ((r = unit_add_dependency(other, UNIT_REQUIRES, UNIT(m))) < 0)
 132                                 return r;
 133                 }
 134         }
 135
 136         return 0;
 137 }
 138
 139 static int mount_add_one(Manager *m, const char *what, const char *where) {
 140         char *e;
 141         int r;
 142         Unit *u;
 143         bool delete;
 144
 145         assert(what);
 146         assert(where);
 147
 148         /* probably some kind of swap, which we don't cover for now */
 149         if (where[0] != '/')
 150                 return 0;
 151
 152         if (streq(where, "/"))
 153                 e = strdup("rootfs.mount");
 154         else
 155                 e = unit_name_escape_path("fs-", where+1, ".mount");
 156
 157         if (!e)
 158                 return -ENOMEM;
 159
 160         if (!(u = manager_get_unit(m, e))) {
 161                 delete = true;
 162
 163                 if (!(u = unit_new(m))) {
 164                         free(e);
 165                         return -ENOMEM;
 166                 }
 167
 168                 r = unit_add_name(u, e);
 169                 free(e);
 170
 171                 if (r < 0)
 172                         goto fail;
 173
 174                 if (!(MOUNT(u)->what = strdup(what)) ||
 175                     !(MOUNT(u)->where = strdup(where)) ||
 176                     !(u->meta.description = strdup(where))) {
 177                         r = -ENOMEM;
 178                         goto fail;
 179                 }
 180         } else {
 181                 delete = false;
 182                 free(e);
 183         }
 184
 185         if ((r = mount_add_node_links(MOUNT(u))) < 0)
 186                 goto fail;
 187
 188         if ((r = mount_add_path_links(MOUNT(u))) < 0)
 189                 goto fail;
 190
 191         unit_add_to_load_queue(u);
 192         return 0;
 193
 194 fail:
 195         if (delete && u)
 196                 unit_free(u);
 197
 198         return 0;
 199 }
 200
 201 static char *fstab_node_to_udev_node(char *p) {
 202         char *dn, *t;
 203         int r;
 204
 205         /* FIXME: to follow udev's logic 100% we need to leave valid
 206          * UTF8 chars unescaped */
 207
 208         if (startswith(p, "LABEL=")) {
 209
 210                 if (!(t = strdup(p+6)))
 211                         return NULL;
 212
 213                 r = asprintf(&dn, "/dev/disk/by-label/%s", xescape(t, "/ "));
 214                 free(t);
 215
 216                 if (r < 0)
 217                         return NULL;
 218
 219                 return dn;
 220         }
 221
 222         if (startswith(p, "UUID=")) {
 223
 224                 if (!(t = strdup(p+5)))
 225                         return NULL;
 226
 227                 r = asprintf(&dn, "/dev/disk/by-uuid/%s", ascii_strlower(xescape(t, "/ ")));
 228                 free(t);
 229
 230                 if (r < 0)
 231                         return NULL;
 232
 233                 return dn;
 234         }
 235
 236         return strdup(p);
 237 }
 238
 239 static int mount_load_etc_fstab(Manager *m) {
 240         FILE *f;
 241         int r;
 242         struct mntent* me;
 243
 244         assert(m);
 245
 246         errno = 0;
 247         if (!(f = setmntent("/etc/fstab", "r")))
 248                 return -errno;
 249
 250         while ((me = getmntent(f))) {
 251                 char *where, *what;
 252
 253                 if (!(what = fstab_node_to_udev_node(me->mnt_fsname))) {
 254                         r = -ENOMEM;
 255                         goto finish;
 256                 }
 257
 258                 if (!(where = strdup(me->mnt_dir))) {
 259                         free(what);
 260                         r = -ENOMEM;
 261                         goto finish;
 262                 }
 263
 264                 if (what[0] == '/')
 265                         path_kill_slashes(what);
 266
 267                 if (where[0] == '/')
 268                         path_kill_slashes(where);
 269
 270                 r = mount_add_one(m, what, where);
 271                 free(what);
 272                 free(where);
 273
 274                 if (r < 0)
 275                         goto finish;
 276         }
 277
 278         r = 0;
 279 finish:
 280
 281         endmntent(f);
 282         return r;
 283 }
 284
 285 static int mount_load_proc_mounts(Manager *m) {
 286         FILE *f;
 287         int r;
 288
 289         assert(m);
 290
 291         if (!(f = fopen("/proc/self/mountinfo", "r")))
 292                 return -errno;
 293
 294         for (;;) {
 295                 int k;
 296                 char *device, *path, *d, *p;
 297
 298                 if ((k = fscanf(f,
 299                                 "%*s "       /* (1) mount id */
 300                                 "%*s "       /* (2) parent id */
 301                                 "%*s "       /* (3) major:minor */
 302                                 "%*s "       /* (4) root */
 303                                 "%ms "       /* (5) mount point */
 304                                 "%*s"        /* (6) mount options */
 305                                 "%*[^-]"     /* (7) optional fields */
 306                                 "- "         /* (8) seperator */
 307                                 "%*s "       /* (9) file system type */
 308                                 "%ms"       /* (10) mount source */
 309                                 "%*[^\n]", /* some rubbish at the end */
 310                                 &path,
 311                                 &device)) != 2) {
 312
 313                         if (k == EOF) {
 314                                 if (feof(f))
 315                                         break;
 316
 317                                 r = -errno;
 318                                 goto finish;
 319                         }
 320
 321                         r = -EBADMSG;
 322                         goto finish;
 323                 }
 324
 325                 if (!(d = cunescape(device))) {
 326                         free(device);
 327                         free(path);
 328                         r = -ENOMEM;
 329                         goto finish;
 330                 }
 331                 free(device);
 332
 333                 if (!(p = cunescape(path))) {
 334                         free(d);
 335                         free(path);
 336                         r = -ENOMEM;
 337                         goto finish;
 338                 }
 339                 free(path);
 340
 341                 r = mount_add_one(m, d, p);
 342                 free(d);
 343                 free(p);
 344
 345                 if (r < 0)
 346                         goto finish;
 347         }
 348
 349         r = 0;
 350
 351 finish:
 352         fclose(f);
 353
 354         return r;
 355 }
 356
 357 static int mount_enumerate(Manager *m) {
 358         int r;
 359         assert(m);
 360
 361         if ((r = mount_load_etc_fstab(m)) < 0)
 362                 goto fail;
 363
 364         if ((r = mount_load_proc_mounts(m)) < 0)
 365                 goto fail;
 366
 367         return 0;
 368
 369 fail:
 370         mount_shutdown(m);
 371         return r;
 372 }
 373
 374 static UnitActiveState mount_active_state(Unit *u) {
 375
 376         static const UnitActiveState table[_MOUNT_STATE_MAX] = {
 377                 [MOUNT_DEAD] = UNIT_INACTIVE,
 378                 [MOUNT_MOUNTING] = UNIT_ACTIVATING,
 379                 [MOUNT_MOUNTED] = UNIT_ACTIVE,
 380                 [MOUNT_UNMOUNTING] = UNIT_DEACTIVATING,
 381                 [MOUNT_MAINTAINANCE] = UNIT_INACTIVE,
 382         };
 383
 384         return table[MOUNT(u)->state];
 385 }
 386
 387 const UnitVTable mount_vtable = {
 388         .suffix = ".mount",
 389
 390         .init = mount_init,
 391         .done = mount_done,
 392         .dump = mount_dump,
 393
 394         .enumerate = mount_enumerate,
 395         .shutdown = mount_shutdown,
 396
 397         .active_state = mount_active_state
 398 };