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[thirdparty/systemd.git] / src / core / mount.c
1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3 #include <errno.h>
4 #include <signal.h>
5 #include <stdio.h>
6 #include <sys/epoll.h>
7
8 #include "sd-messages.h"
9
10 #include "alloc-util.h"
11 #include "dbus-mount.h"
12 #include "dbus-unit.h"
13 #include "device.h"
14 #include "exit-status.h"
15 #include "format-util.h"
16 #include "fs-util.h"
17 #include "fstab-util.h"
18 #include "initrd-util.h"
19 #include "libmount-util.h"
20 #include "log.h"
21 #include "manager.h"
22 #include "mkdir-label.h"
23 #include "mount-setup.h"
24 #include "mount.h"
25 #include "mountpoint-util.h"
26 #include "parse-util.h"
27 #include "path-util.h"
28 #include "process-util.h"
29 #include "serialize.h"
30 #include "special.h"
31 #include "stat-util.h"
32 #include "string-table.h"
33 #include "string-util.h"
34 #include "strv.h"
35 #include "unit-name.h"
36 #include "unit.h"
37
38 #define RETRY_UMOUNT_MAX 32
39
40 static const UnitActiveState state_translation_table[_MOUNT_STATE_MAX] = {
41 [MOUNT_DEAD] = UNIT_INACTIVE,
42 [MOUNT_MOUNTING] = UNIT_ACTIVATING,
43 [MOUNT_MOUNTING_DONE] = UNIT_ACTIVATING,
44 [MOUNT_MOUNTED] = UNIT_ACTIVE,
45 [MOUNT_REMOUNTING] = UNIT_RELOADING,
46 [MOUNT_UNMOUNTING] = UNIT_DEACTIVATING,
47 [MOUNT_REMOUNTING_SIGTERM] = UNIT_RELOADING,
48 [MOUNT_REMOUNTING_SIGKILL] = UNIT_RELOADING,
49 [MOUNT_UNMOUNTING_SIGTERM] = UNIT_DEACTIVATING,
50 [MOUNT_UNMOUNTING_SIGKILL] = UNIT_DEACTIVATING,
51 [MOUNT_FAILED] = UNIT_FAILED,
52 [MOUNT_CLEANING] = UNIT_MAINTENANCE,
53 };
54
55 static int mount_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
56 static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
57 static void mount_enter_dead(Mount *m, MountResult f);
58 static void mount_enter_mounted(Mount *m, MountResult f);
59 static void mount_cycle_clear(Mount *m);
60 static int mount_process_proc_self_mountinfo(Manager *m);
61
62 static bool MOUNT_STATE_WITH_PROCESS(MountState state) {
63 return IN_SET(state,
64 MOUNT_MOUNTING,
65 MOUNT_MOUNTING_DONE,
66 MOUNT_REMOUNTING,
67 MOUNT_REMOUNTING_SIGTERM,
68 MOUNT_REMOUNTING_SIGKILL,
69 MOUNT_UNMOUNTING,
70 MOUNT_UNMOUNTING_SIGTERM,
71 MOUNT_UNMOUNTING_SIGKILL,
72 MOUNT_CLEANING);
73 }
74
75 static MountParameters* get_mount_parameters_fragment(Mount *m) {
76 assert(m);
77
78 if (m->from_fragment)
79 return &m->parameters_fragment;
80
81 return NULL;
82 }
83
84 static MountParameters* get_mount_parameters(Mount *m) {
85 assert(m);
86
87 if (m->from_proc_self_mountinfo)
88 return &m->parameters_proc_self_mountinfo;
89
90 return get_mount_parameters_fragment(m);
91 }
92
93 static bool mount_is_network(const MountParameters *p) {
94 assert(p);
95
96 if (fstab_test_option(p->options, "_netdev\0"))
97 return true;
98
99 if (p->fstype && fstype_is_network(p->fstype))
100 return true;
101
102 return false;
103 }
104
105 static bool mount_is_nofail(const Mount *m) {
106 assert(m);
107
108 if (!m->from_fragment)
109 return false;
110
111 return fstab_test_yes_no_option(m->parameters_fragment.options, "nofail\0" "fail\0");
112 }
113
114 static bool mount_is_loop(const MountParameters *p) {
115 assert(p);
116
117 if (fstab_test_option(p->options, "loop\0"))
118 return true;
119
120 return false;
121 }
122
123 static bool mount_is_bind(const MountParameters *p) {
124 assert(p);
125 return fstab_is_bind(p->options, p->fstype);
126 }
127
128 static int mount_is_bound_to_device(Mount *m) {
129 _cleanup_free_ char *value = NULL;
130 const MountParameters *p;
131 int r;
132
133 assert(m);
134
135 /* Determines whether to place a Requires= or BindsTo= dependency on the backing device unit. We do
136 * this by checking for the x-systemd.device-bound= mount option. If it is enabled we use BindsTo=,
137 * otherwise Requires=. But note that we might combine the latter with StopPropagatedFrom=, see
138 * below. */
139
140 p = get_mount_parameters(m);
141 if (!p)
142 return false;
143
144 r = fstab_filter_options(p->options, "x-systemd.device-bound\0", NULL, &value, NULL, NULL);
145 if (r < 0)
146 return r;
147 if (r == 0)
148 return -EIDRM; /* If unspecified at all, return recognizable error */
149
150 if (isempty(value))
151 return true;
152
153 return parse_boolean(value);
154 }
155
156 static bool mount_propagate_stop(Mount *m) {
157 int r;
158
159 assert(m);
160
161 r = mount_is_bound_to_device(m);
162 if (r >= 0)
163 /* If x-systemd.device-bound=no is explicitly requested by user, don't try to set StopPropagatedFrom=.
164 * Also don't bother if true, since with BindsTo= the stop propagation is implicit. */
165 return false;
166 if (r != -EIDRM)
167 log_debug_errno(r, "Failed to get x-systemd.device-bound= option, ignoring: %m");
168
169 return m->from_fragment; /* let's propagate stop whenever this is an explicitly configured unit,
170 * otherwise let's not bother. */
171 }
172
173 static bool mount_needs_quota(const MountParameters *p) {
174 assert(p);
175
176 if (p->fstype && !fstype_needs_quota(p->fstype))
177 return false;
178
179 if (mount_is_bind(p))
180 return false;
181
182 return fstab_test_option(p->options,
183 "usrquota\0" "grpquota\0" "quota\0" "usrjquota\0" "grpjquota\0");
184 }
185
186 static void mount_init(Unit *u) {
187 Mount *m = MOUNT(u);
188
189 assert(m);
190 assert(u);
191 assert(u->load_state == UNIT_STUB);
192
193 m->timeout_usec = u->manager->defaults.timeout_start_usec;
194
195 m->exec_context.std_output = u->manager->defaults.std_output;
196 m->exec_context.std_error = u->manager->defaults.std_error;
197
198 m->directory_mode = 0755;
199
200 /* We need to make sure that /usr/bin/mount is always called
201 * in the same process group as us, so that the autofs kernel
202 * side doesn't send us another mount request while we are
203 * already trying to comply its last one. */
204 m->exec_context.same_pgrp = true;
205
206 m->control_pid = PIDREF_NULL;
207 m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
208
209 u->ignore_on_isolate = true;
210 }
211
212 static int mount_arm_timer(Mount *m, bool relative, usec_t usec) {
213 assert(m);
214
215 return unit_arm_timer(UNIT(m), &m->timer_event_source, relative, usec, mount_dispatch_timer);
216 }
217
218 static void mount_unwatch_control_pid(Mount *m) {
219 assert(m);
220
221 if (!pidref_is_set(&m->control_pid))
222 return;
223
224 unit_unwatch_pidref(UNIT(m), &m->control_pid);
225 pidref_done(&m->control_pid);
226 }
227
228 static void mount_parameters_done(MountParameters *p) {
229 assert(p);
230
231 p->what = mfree(p->what);
232 p->options = mfree(p->options);
233 p->fstype = mfree(p->fstype);
234 }
235
236 static void mount_done(Unit *u) {
237 Mount *m = MOUNT(u);
238
239 assert(m);
240
241 m->where = mfree(m->where);
242
243 mount_parameters_done(&m->parameters_proc_self_mountinfo);
244 mount_parameters_done(&m->parameters_fragment);
245
246 m->exec_runtime = exec_runtime_free(m->exec_runtime);
247 exec_command_done_array(m->exec_command, _MOUNT_EXEC_COMMAND_MAX);
248 m->control_command = NULL;
249
250 mount_unwatch_control_pid(m);
251
252 m->timer_event_source = sd_event_source_disable_unref(m->timer_event_source);
253 }
254
255 static int update_parameters_proc_self_mountinfo(
256 Mount *m,
257 const char *what,
258 const char *options,
259 const char *fstype) {
260
261 MountParameters *p;
262 int r, q, w;
263
264 p = &m->parameters_proc_self_mountinfo;
265
266 r = free_and_strdup(&p->what, what);
267 if (r < 0)
268 return r;
269
270 q = free_and_strdup(&p->options, options);
271 if (q < 0)
272 return q;
273
274 w = free_and_strdup(&p->fstype, fstype);
275 if (w < 0)
276 return w;
277
278 return r > 0 || q > 0 || w > 0;
279 }
280
281 static int mount_add_mount_dependencies(Mount *m) {
282 MountParameters *pm;
283 Unit *other;
284 Set *s;
285 int r;
286
287 assert(m);
288
289 if (!path_equal(m->where, "/")) {
290 _cleanup_free_ char *parent = NULL;
291
292 /* Adds in links to other mount points that might lie further up in the hierarchy */
293
294 r = path_extract_directory(m->where, &parent);
295 if (r < 0)
296 return r;
297
298 r = unit_require_mounts_for(UNIT(m), parent, UNIT_DEPENDENCY_IMPLICIT);
299 if (r < 0)
300 return r;
301 }
302
303 /* Adds in dependencies to other mount points that might be needed for the source path (if this is a bind mount
304 * or a loop mount) to be available. */
305 pm = get_mount_parameters_fragment(m);
306 if (pm && pm->what &&
307 path_is_absolute(pm->what) &&
308 (mount_is_bind(pm) || mount_is_loop(pm) || !mount_is_network(pm))) {
309
310 r = unit_require_mounts_for(UNIT(m), pm->what, UNIT_DEPENDENCY_FILE);
311 if (r < 0)
312 return r;
313 }
314
315 /* Adds in dependencies to other units that use this path or paths further down in the hierarchy */
316 s = manager_get_units_requiring_mounts_for(UNIT(m)->manager, m->where);
317 SET_FOREACH(other, s) {
318
319 if (other->load_state != UNIT_LOADED)
320 continue;
321
322 if (other == UNIT(m))
323 continue;
324
325 r = unit_add_dependency(other, UNIT_AFTER, UNIT(m), true, UNIT_DEPENDENCY_PATH);
326 if (r < 0)
327 return r;
328
329 if (UNIT(m)->fragment_path) {
330 /* If we have fragment configuration, then make this dependency required */
331 r = unit_add_dependency(other, UNIT_REQUIRES, UNIT(m), true, UNIT_DEPENDENCY_PATH);
332 if (r < 0)
333 return r;
334 }
335 }
336
337 return 0;
338 }
339
340 static int mount_add_device_dependencies(Mount *m) {
341 UnitDependencyMask mask;
342 MountParameters *p;
343 UnitDependency dep;
344 int r;
345
346 assert(m);
347
348 log_unit_trace(UNIT(m), "Processing implicit device dependencies");
349
350 p = get_mount_parameters(m);
351 if (!p) {
352 log_unit_trace(UNIT(m), "Missing mount parameters, skipping implicit device dependencies");
353 return 0;
354 }
355
356 if (!p->what) {
357 log_unit_trace(UNIT(m), "Missing mount source, skipping implicit device dependencies");
358 return 0;
359 }
360
361 if (mount_is_bind(p)) {
362 log_unit_trace(UNIT(m), "Mount unit is a bind mount, skipping implicit device dependencies");
363 return 0;
364 }
365
366 if (!is_device_path(p->what)) {
367 log_unit_trace(UNIT(m), "Mount source is not a device path, skipping implicit device dependencies");
368 return 0;
369 }
370
371 /* /dev/root is a really weird thing, it's not a real device, but just a path the kernel exports for
372 * the root file system specified on the kernel command line. Ignore it here. */
373 if (PATH_IN_SET(p->what, "/dev/root", "/dev/nfs")) {
374 log_unit_trace(UNIT(m), "Mount source is in /dev/root or /dev/nfs, skipping implicit device dependencies");
375 return 0;
376 }
377
378 if (path_equal(m->where, "/")) {
379 log_unit_trace(UNIT(m), "Mount destination is '/', skipping implicit device dependencies");
380 return 0;
381 }
382
383 /* Mount units from /proc/self/mountinfo are not bound to devices by default since they're subject to
384 * races when mounts are established by other tools with different backing devices than what we
385 * maintain. The user can still force this to be a BindsTo= dependency with an appropriate option (or
386 * udev property) so the mount units are automatically stopped when the device disappears
387 * suddenly. */
388 dep = mount_is_bound_to_device(m) > 0 ? UNIT_BINDS_TO : UNIT_REQUIRES;
389
390 /* We always use 'what' from /proc/self/mountinfo if mounted */
391 mask = m->from_proc_self_mountinfo ? UNIT_DEPENDENCY_MOUNTINFO : UNIT_DEPENDENCY_MOUNT_FILE;
392
393 r = unit_add_node_dependency(UNIT(m), p->what, dep, mask);
394 if (r < 0)
395 return r;
396 if (r > 0)
397 log_unit_trace(UNIT(m), "Added %s dependency on %s", unit_dependency_to_string(dep), p->what);
398
399 if (mount_propagate_stop(m)) {
400 r = unit_add_node_dependency(UNIT(m), p->what, UNIT_STOP_PROPAGATED_FROM, mask);
401 if (r < 0)
402 return r;
403 if (r > 0)
404 log_unit_trace(UNIT(m), "Added %s dependency on %s",
405 unit_dependency_to_string(UNIT_STOP_PROPAGATED_FROM), p->what);
406 }
407
408 r = unit_add_blockdev_dependency(UNIT(m), p->what, mask);
409 if (r > 0)
410 log_unit_trace(UNIT(m), "Added %s dependency on %s", unit_dependency_to_string(UNIT_AFTER), p->what);
411
412 return 0;
413 }
414
415 static int mount_add_quota_dependencies(Mount *m) {
416 MountParameters *p;
417 int r;
418
419 assert(m);
420
421 if (!MANAGER_IS_SYSTEM(UNIT(m)->manager))
422 return 0;
423
424 p = get_mount_parameters_fragment(m);
425 if (!p)
426 return 0;
427
428 if (!mount_needs_quota(p))
429 return 0;
430
431 r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_WANTS, SPECIAL_QUOTACHECK_SERVICE,
432 /* add_reference= */ true, UNIT_DEPENDENCY_FILE);
433 if (r < 0)
434 return r;
435
436 r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_WANTS, SPECIAL_QUOTAON_SERVICE,
437 /* add_reference= */true, UNIT_DEPENDENCY_FILE);
438 if (r < 0)
439 return r;
440
441 return 0;
442 }
443
444 static bool mount_is_extrinsic(Unit *u) {
445 MountParameters *p;
446 Mount *m = MOUNT(u);
447 assert(m);
448
449 /* Returns true for all units that are "magic" and should be excluded from the usual
450 * start-up and shutdown dependencies. We call them "extrinsic" here, as they are generally
451 * mounted outside of the systemd dependency logic. We shouldn't attempt to manage them
452 * ourselves but it's fine if the user operates on them with us. */
453
454 /* We only automatically manage mounts if we are in system mode */
455 if (MANAGER_IS_USER(u->manager))
456 return true;
457
458 p = get_mount_parameters(m);
459 if (p && fstab_is_extrinsic(m->where, p->options))
460 return true;
461
462 return false;
463 }
464
465 static bool mount_is_credentials(Mount *m) {
466 const char *e;
467
468 assert(m);
469
470 /* Returns true if this is a credentials mount. We don't want automatic dependencies on credential
471 * mounts, since they are managed by us for even the earliest services, and we never want anything to
472 * be ordered before them hence. */
473
474 e = path_startswith(m->where, UNIT(m)->manager->prefix[EXEC_DIRECTORY_RUNTIME]);
475 if (!e)
476 return false;
477
478 return !isempty(path_startswith(e, "credentials"));
479 }
480
481 static int mount_add_default_ordering_dependencies(Mount *m, MountParameters *p, UnitDependencyMask mask) {
482 const char *after, *before, *e;
483 int r;
484
485 assert(m);
486
487 e = path_startswith(m->where, "/sysroot");
488 if (e && in_initrd()) {
489 /* All mounts under /sysroot need to happen later, at initrd-fs.target time. IOW,
490 * it's not technically part of the basic initrd filesystem itself, and so
491 * shouldn't inherit the default Before=local-fs.target dependency. However,
492 * these mounts still need to start after local-fs-pre.target, as a sync point
493 * for things like systemd-hibernate-resume.service that should start before
494 * any mounts. */
495
496 after = SPECIAL_LOCAL_FS_PRE_TARGET;
497 before = isempty(e) ? SPECIAL_INITRD_ROOT_FS_TARGET : SPECIAL_INITRD_FS_TARGET;
498
499 } else if (in_initrd() && path_startswith(m->where, "/sysusr/usr")) {
500 after = SPECIAL_LOCAL_FS_PRE_TARGET;
501 before = SPECIAL_INITRD_USR_FS_TARGET;
502
503 } else if (mount_is_credentials(m))
504 after = before = NULL;
505
506 else if (mount_is_network(p)) {
507 after = SPECIAL_REMOTE_FS_PRE_TARGET;
508 before = SPECIAL_REMOTE_FS_TARGET;
509
510 } else {
511 after = SPECIAL_LOCAL_FS_PRE_TARGET;
512 before = SPECIAL_LOCAL_FS_TARGET;
513 }
514
515 if (before && !mount_is_nofail(m)) {
516 r = unit_add_dependency_by_name(UNIT(m), UNIT_BEFORE, before, /* add_reference= */ true, mask);
517 if (r < 0)
518 return r;
519 }
520
521 if (after) {
522 r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, after, /* add_reference= */ true, mask);
523 if (r < 0)
524 return r;
525 }
526
527 r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET,
528 /* add_reference= */ true, mask);
529 if (r < 0)
530 return r;
531
532 /* If this is a tmpfs mount then we have to unmount it before we try to deactivate swaps */
533 if (streq_ptr(p->fstype, "tmpfs") && !mount_is_credentials(m)) {
534 r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, SPECIAL_SWAP_TARGET,
535 /* add_reference= */ true, mask);
536 if (r < 0)
537 return r;
538 }
539
540 return 0;
541 }
542
543 static int mount_add_default_network_dependencies(Mount *m, MountParameters *p, UnitDependencyMask mask) {
544 int r;
545
546 assert(m);
547
548 if (!mount_is_network(p))
549 return 0;
550
551 /* We order ourselves after network.target. This is primarily useful at shutdown: services that take
552 * down the network should order themselves before network.target, so that they are shut down only
553 * after this mount unit is stopped. */
554
555 r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, SPECIAL_NETWORK_TARGET,
556 /* add_reference= */ true, mask);
557 if (r < 0)
558 return r;
559
560 /* We pull in network-online.target, and order ourselves after it. This is useful at start-up to
561 * actively pull in tools that want to be started before we start mounting network file systems, and
562 * whose purpose it is to delay this until the network is "up". */
563
564 return unit_add_two_dependencies_by_name(UNIT(m), UNIT_WANTS, UNIT_AFTER, SPECIAL_NETWORK_ONLINE_TARGET,
565 /* add_reference= */ true, mask);
566 }
567
568 static int mount_add_default_dependencies(Mount *m) {
569 UnitDependencyMask mask;
570 MountParameters *p;
571 int r;
572
573 assert(m);
574
575 if (!UNIT(m)->default_dependencies)
576 return 0;
577
578 /* We do not add any default dependencies to /, /usr or /run/initramfs/, since they are
579 * guaranteed to stay mounted the whole time, since our system is on it. Also, don't
580 * bother with anything mounted below virtual file systems, it's also going to be virtual,
581 * and hence not worth the effort. */
582 if (mount_is_extrinsic(UNIT(m)))
583 return 0;
584
585 p = get_mount_parameters(m);
586 if (!p)
587 return 0;
588
589 mask = m->from_proc_self_mountinfo ? UNIT_DEPENDENCY_MOUNTINFO : UNIT_DEPENDENCY_MOUNT_FILE;
590
591 r = mount_add_default_ordering_dependencies(m, p, mask);
592 if (r < 0)
593 return r;
594
595 r = mount_add_default_network_dependencies(m, p, mask);
596 if (r < 0)
597 return r;
598
599 return 0;
600 }
601
602 static int mount_verify(Mount *m) {
603 _cleanup_free_ char *e = NULL;
604 MountParameters *p;
605 int r;
606
607 assert(m);
608 assert(UNIT(m)->load_state == UNIT_LOADED);
609
610 if (!m->from_fragment && !m->from_proc_self_mountinfo && !UNIT(m)->perpetual)
611 return -ENOENT;
612
613 r = unit_name_from_path(m->where, ".mount", &e);
614 if (r < 0)
615 return log_unit_error_errno(UNIT(m), r, "Failed to generate unit name from mount path: %m");
616
617 if (!unit_has_name(UNIT(m), e))
618 return log_unit_error_errno(UNIT(m), SYNTHETIC_ERRNO(ENOEXEC), "Where= setting doesn't match unit name. Refusing.");
619
620 if (mount_point_is_api(m->where) || mount_point_ignore(m->where))
621 return log_unit_error_errno(UNIT(m), SYNTHETIC_ERRNO(ENOEXEC), "Cannot create mount unit for API file system %s. Refusing.", m->where);
622
623 p = get_mount_parameters_fragment(m);
624 if (p && !p->what && !UNIT(m)->perpetual)
625 return log_unit_error_errno(UNIT(m), SYNTHETIC_ERRNO(ENOEXEC),
626 "What= setting is missing. Refusing.");
627
628 if (m->exec_context.pam_name && m->kill_context.kill_mode != KILL_CONTROL_GROUP)
629 return log_unit_error_errno(UNIT(m), SYNTHETIC_ERRNO(ENOEXEC), "Unit has PAM enabled. Kill mode must be set to control-group'. Refusing.");
630
631 return 0;
632 }
633
634 static int mount_add_non_exec_dependencies(Mount *m) {
635 int r;
636
637 assert(m);
638
639 /* We may be called due to this mount appearing in /proc/self/mountinfo, hence we clear all existing
640 * dependencies that were initialized from the unit file but whose final value really depends on the
641 * content of /proc/self/mountinfo. Some (such as m->where) might have become stale now. */
642 unit_remove_dependencies(UNIT(m), UNIT_DEPENDENCY_MOUNTINFO | UNIT_DEPENDENCY_MOUNT_FILE);
643
644 if (!m->where)
645 return 0;
646
647 /* Adds in all dependencies directly responsible for ordering the mount, as opposed to dependencies
648 * resulting from the ExecContext and such. */
649
650 r = mount_add_device_dependencies(m);
651 if (r < 0)
652 return r;
653
654 r = mount_add_mount_dependencies(m);
655 if (r < 0)
656 return r;
657
658 r = mount_add_quota_dependencies(m);
659 if (r < 0)
660 return r;
661
662 r = mount_add_default_dependencies(m);
663 if (r < 0)
664 return r;
665
666 return 0;
667 }
668
669 static int mount_add_extras(Mount *m) {
670 Unit *u = UNIT(m);
671 int r;
672
673 assert(m);
674
675 /* Note: this call might be called after we already have been loaded once (and even when it has already been
676 * activated), in case data from /proc/self/mountinfo has changed. This means all code here needs to be ready
677 * to run with an already set up unit. */
678
679 if (u->fragment_path)
680 m->from_fragment = true;
681
682 if (!m->where) {
683 r = unit_name_to_path(u->id, &m->where);
684 if (r == -ENAMETOOLONG)
685 log_unit_error_errno(u, r, "Failed to derive mount point path from unit name, because unit name is hashed. "
686 "Set \"Where=\" in the unit file explicitly.");
687 if (r < 0)
688 return r;
689 }
690
691 path_simplify(m->where);
692
693 if (!u->description) {
694 r = unit_set_description(u, m->where);
695 if (r < 0)
696 return r;
697 }
698
699 r = unit_patch_contexts(u);
700 if (r < 0)
701 return r;
702
703 r = unit_add_exec_dependencies(u, &m->exec_context);
704 if (r < 0)
705 return r;
706
707 r = unit_set_default_slice(u);
708 if (r < 0)
709 return r;
710
711 r = mount_add_non_exec_dependencies(m);
712 if (r < 0)
713 return r;
714
715 return 0;
716 }
717
718 static void mount_load_root_mount(Unit *u) {
719 assert(u);
720
721 if (!unit_has_name(u, SPECIAL_ROOT_MOUNT))
722 return;
723
724 u->perpetual = true;
725 u->default_dependencies = false;
726
727 /* The stdio/kmsg bridge socket is on /, in order to avoid a dep loop, don't use kmsg logging for -.mount */
728 MOUNT(u)->exec_context.std_output = EXEC_OUTPUT_NULL;
729 MOUNT(u)->exec_context.std_input = EXEC_INPUT_NULL;
730
731 if (!u->description)
732 u->description = strdup("Root Mount");
733 }
734
735 static int mount_load(Unit *u) {
736 Mount *m = MOUNT(u);
737 int r, q = 0;
738
739 assert(m);
740 assert(u);
741 assert(u->load_state == UNIT_STUB);
742
743 mount_load_root_mount(u);
744
745 bool fragment_optional = m->from_proc_self_mountinfo || u->perpetual;
746 r = unit_load_fragment_and_dropin(u, !fragment_optional);
747
748 /* Add in some extras. Note we do this in all cases (even if we failed to load the unit) when announced by the
749 * kernel, because we need some things to be set up no matter what when the kernel establishes a mount and thus
750 * we need to update the state in our unit to track it. After all, consider that we don't allow changing the
751 * 'slice' field for a unit once it is active. */
752 if (u->load_state == UNIT_LOADED || m->from_proc_self_mountinfo || u->perpetual)
753 q = mount_add_extras(m);
754
755 if (r < 0)
756 return r;
757 if (q < 0)
758 return q;
759 if (u->load_state != UNIT_LOADED)
760 return 0;
761
762 return mount_verify(m);
763 }
764
765 static void mount_set_state(Mount *m, MountState state) {
766 MountState old_state;
767 assert(m);
768
769 if (m->state != state)
770 bus_unit_send_pending_change_signal(UNIT(m), false);
771
772 old_state = m->state;
773 m->state = state;
774
775 if (!MOUNT_STATE_WITH_PROCESS(state)) {
776 m->timer_event_source = sd_event_source_disable_unref(m->timer_event_source);
777 mount_unwatch_control_pid(m);
778 m->control_command = NULL;
779 m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
780 }
781
782 if (state != old_state)
783 log_unit_debug(UNIT(m), "Changed %s -> %s", mount_state_to_string(old_state), mount_state_to_string(state));
784
785 unit_notify(UNIT(m), state_translation_table[old_state], state_translation_table[state], m->reload_result == MOUNT_SUCCESS);
786 }
787
788 static int mount_coldplug(Unit *u) {
789 Mount *m = MOUNT(u);
790 int r;
791
792 assert(m);
793 assert(m->state == MOUNT_DEAD);
794
795 if (m->deserialized_state == m->state)
796 return 0;
797
798 if (pidref_is_set(&m->control_pid) &&
799 pidref_is_unwaited(&m->control_pid) > 0 &&
800 MOUNT_STATE_WITH_PROCESS(m->deserialized_state)) {
801
802 r = unit_watch_pidref(UNIT(m), &m->control_pid, /* exclusive= */ false);
803 if (r < 0)
804 return r;
805
806 r = mount_arm_timer(m, /* relative= */ false, usec_add(u->state_change_timestamp.monotonic, m->timeout_usec));
807 if (r < 0)
808 return r;
809 }
810
811 if (!IN_SET(m->deserialized_state, MOUNT_DEAD, MOUNT_FAILED))
812 (void) unit_setup_exec_runtime(u);
813
814 mount_set_state(m, m->deserialized_state);
815 return 0;
816 }
817
818 static void mount_catchup(Unit *u) {
819 Mount *m = MOUNT(ASSERT_PTR(u));
820
821 assert(m);
822
823 /* Adjust the deserialized state. See comments in mount_process_proc_self_mountinfo(). */
824 if (m->from_proc_self_mountinfo)
825 switch (m->state) {
826 case MOUNT_DEAD:
827 case MOUNT_FAILED:
828 assert(!pidref_is_set(&m->control_pid));
829 (void) unit_acquire_invocation_id(u);
830 mount_cycle_clear(m);
831 mount_enter_mounted(m, MOUNT_SUCCESS);
832 break;
833 case MOUNT_MOUNTING:
834 assert(pidref_is_set(&m->control_pid));
835 mount_set_state(m, MOUNT_MOUNTING_DONE);
836 break;
837 default:
838 break;
839 }
840 else
841 switch (m->state) {
842 case MOUNT_MOUNTING_DONE:
843 assert(pidref_is_set(&m->control_pid));
844 mount_set_state(m, MOUNT_MOUNTING);
845 break;
846 case MOUNT_MOUNTED:
847 assert(!pidref_is_set(&m->control_pid));
848 mount_enter_dead(m, MOUNT_SUCCESS);
849 break;
850 default:
851 break;
852 }
853 }
854
855 static void mount_dump(Unit *u, FILE *f, const char *prefix) {
856 Mount *m = MOUNT(u);
857 MountParameters *p;
858
859 assert(m);
860 assert(f);
861
862 p = get_mount_parameters(m);
863
864 fprintf(f,
865 "%sMount State: %s\n"
866 "%sResult: %s\n"
867 "%sClean Result: %s\n"
868 "%sWhere: %s\n"
869 "%sWhat: %s\n"
870 "%sFile System Type: %s\n"
871 "%sOptions: %s\n"
872 "%sFrom /proc/self/mountinfo: %s\n"
873 "%sFrom fragment: %s\n"
874 "%sExtrinsic: %s\n"
875 "%sDirectoryMode: %04o\n"
876 "%sSloppyOptions: %s\n"
877 "%sLazyUnmount: %s\n"
878 "%sForceUnmount: %s\n"
879 "%sReadWriteOnly: %s\n"
880 "%sTimeoutSec: %s\n",
881 prefix, mount_state_to_string(m->state),
882 prefix, mount_result_to_string(m->result),
883 prefix, mount_result_to_string(m->clean_result),
884 prefix, m->where,
885 prefix, p ? strna(p->what) : "n/a",
886 prefix, p ? strna(p->fstype) : "n/a",
887 prefix, p ? strna(p->options) : "n/a",
888 prefix, yes_no(m->from_proc_self_mountinfo),
889 prefix, yes_no(m->from_fragment),
890 prefix, yes_no(mount_is_extrinsic(u)),
891 prefix, m->directory_mode,
892 prefix, yes_no(m->sloppy_options),
893 prefix, yes_no(m->lazy_unmount),
894 prefix, yes_no(m->force_unmount),
895 prefix, yes_no(m->read_write_only),
896 prefix, FORMAT_TIMESPAN(m->timeout_usec, USEC_PER_SEC));
897
898 if (pidref_is_set(&m->control_pid))
899 fprintf(f,
900 "%sControl PID: "PID_FMT"\n",
901 prefix, m->control_pid.pid);
902
903 exec_context_dump(&m->exec_context, f, prefix);
904 kill_context_dump(&m->kill_context, f, prefix);
905 cgroup_context_dump(UNIT(m), f, prefix);
906 }
907
908 static int mount_spawn(Mount *m, ExecCommand *c, PidRef *ret_pid) {
909
910 _cleanup_(exec_params_clear) ExecParameters exec_params = EXEC_PARAMETERS_INIT(
911 EXEC_APPLY_SANDBOXING|EXEC_APPLY_CHROOT|EXEC_APPLY_TTY_STDIN);
912 _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL;
913 pid_t pid;
914 int r;
915
916 assert(m);
917 assert(c);
918 assert(ret_pid);
919
920 r = unit_prepare_exec(UNIT(m));
921 if (r < 0)
922 return r;
923
924 r = mount_arm_timer(m, /* relative= */ true, m->timeout_usec);
925 if (r < 0)
926 return r;
927
928 r = unit_set_exec_params(UNIT(m), &exec_params);
929 if (r < 0)
930 return r;
931
932 r = exec_spawn(UNIT(m),
933 c,
934 &m->exec_context,
935 &exec_params,
936 m->exec_runtime,
937 &m->cgroup_context,
938 &pid);
939 if (r < 0)
940 return r;
941
942 r = pidref_set_pid(&pidref, pid);
943 if (r < 0)
944 return r;
945
946 r = unit_watch_pidref(UNIT(m), &pidref, /* exclusive= */ true);
947 if (r < 0)
948 return r;
949
950 *ret_pid = TAKE_PIDREF(pidref);
951 return 0;
952 }
953
954 static void mount_enter_dead(Mount *m, MountResult f) {
955 assert(m);
956
957 if (m->result == MOUNT_SUCCESS)
958 m->result = f;
959
960 unit_log_result(UNIT(m), m->result == MOUNT_SUCCESS, mount_result_to_string(m->result));
961 unit_warn_leftover_processes(UNIT(m), unit_log_leftover_process_stop);
962
963 mount_set_state(m, m->result != MOUNT_SUCCESS ? MOUNT_FAILED : MOUNT_DEAD);
964
965 m->exec_runtime = exec_runtime_destroy(m->exec_runtime);
966
967 unit_destroy_runtime_data(UNIT(m), &m->exec_context);
968
969 unit_unref_uid_gid(UNIT(m), true);
970
971 /* Any dependencies based on /proc/self/mountinfo are now stale. Let's re-generate dependencies from
972 * .mount unit. */
973 (void) mount_add_non_exec_dependencies(m);
974 }
975
976 static void mount_enter_mounted(Mount *m, MountResult f) {
977 assert(m);
978
979 if (m->result == MOUNT_SUCCESS)
980 m->result = f;
981
982 mount_set_state(m, MOUNT_MOUNTED);
983 }
984
985 static void mount_enter_dead_or_mounted(Mount *m, MountResult f) {
986 assert(m);
987
988 /* Enter DEAD or MOUNTED state, depending on what the kernel currently says about the mount point. We use this
989 * whenever we executed an operation, so that our internal state reflects what the kernel says again, after all
990 * ultimately we just mirror the kernel's internal state on this. */
991
992 if (m->from_proc_self_mountinfo)
993 mount_enter_mounted(m, f);
994 else
995 mount_enter_dead(m, f);
996 }
997
998 static int state_to_kill_operation(MountState state) {
999 switch (state) {
1000
1001 case MOUNT_REMOUNTING_SIGTERM:
1002 return KILL_RESTART;
1003
1004 case MOUNT_UNMOUNTING_SIGTERM:
1005 return KILL_TERMINATE;
1006
1007 case MOUNT_REMOUNTING_SIGKILL:
1008 case MOUNT_UNMOUNTING_SIGKILL:
1009 return KILL_KILL;
1010
1011 default:
1012 return _KILL_OPERATION_INVALID;
1013 }
1014 }
1015
1016 static void mount_enter_signal(Mount *m, MountState state, MountResult f) {
1017 int r;
1018
1019 assert(m);
1020
1021 if (m->result == MOUNT_SUCCESS)
1022 m->result = f;
1023
1024 r = unit_kill_context(
1025 UNIT(m),
1026 &m->kill_context,
1027 state_to_kill_operation(state),
1028 /* main_pid= */ NULL,
1029 &m->control_pid,
1030 /* main_pid_alien= */ false);
1031 if (r < 0) {
1032 log_unit_warning_errno(UNIT(m), r, "Failed to kill processes: %m");
1033 goto fail;
1034 }
1035
1036 if (r > 0) {
1037 r = mount_arm_timer(m, /* relative= */ true, m->timeout_usec);
1038 if (r < 0) {
1039 log_unit_warning_errno(UNIT(m), r, "Failed to install timer: %m");
1040 goto fail;
1041 }
1042
1043 mount_set_state(m, state);
1044 } else if (state == MOUNT_REMOUNTING_SIGTERM && m->kill_context.send_sigkill)
1045 mount_enter_signal(m, MOUNT_REMOUNTING_SIGKILL, MOUNT_SUCCESS);
1046 else if (IN_SET(state, MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL))
1047 mount_enter_mounted(m, MOUNT_SUCCESS);
1048 else if (state == MOUNT_UNMOUNTING_SIGTERM && m->kill_context.send_sigkill)
1049 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGKILL, MOUNT_SUCCESS);
1050 else
1051 mount_enter_dead_or_mounted(m, MOUNT_SUCCESS);
1052
1053 return;
1054
1055 fail:
1056 mount_enter_dead_or_mounted(m, MOUNT_FAILURE_RESOURCES);
1057 }
1058
1059 static int mount_set_umount_command(Mount *m, ExecCommand *c) {
1060 int r;
1061
1062 assert(m);
1063 assert(c);
1064
1065 r = exec_command_set(c, UMOUNT_PATH, m->where, "-c", NULL);
1066 if (r < 0)
1067 return r;
1068
1069 if (m->lazy_unmount) {
1070 r = exec_command_append(c, "-l", NULL);
1071 if (r < 0)
1072 return r;
1073 }
1074
1075 if (m->force_unmount) {
1076 r = exec_command_append(c, "-f", NULL);
1077 if (r < 0)
1078 return r;
1079 }
1080
1081 return 0;
1082 }
1083
1084 static void mount_enter_unmounting(Mount *m) {
1085 int r;
1086
1087 assert(m);
1088
1089 /* Start counting our attempts */
1090 if (!IN_SET(m->state,
1091 MOUNT_UNMOUNTING,
1092 MOUNT_UNMOUNTING_SIGTERM,
1093 MOUNT_UNMOUNTING_SIGKILL))
1094 m->n_retry_umount = 0;
1095
1096 m->control_command_id = MOUNT_EXEC_UNMOUNT;
1097 m->control_command = m->exec_command + MOUNT_EXEC_UNMOUNT;
1098
1099 r = mount_set_umount_command(m, m->control_command);
1100 if (r < 0) {
1101 log_unit_warning_errno(UNIT(m), r, "Failed to prepare umount command line: %m");
1102 goto fail;
1103 }
1104
1105 mount_unwatch_control_pid(m);
1106
1107 r = mount_spawn(m, m->control_command, &m->control_pid);
1108 if (r < 0) {
1109 log_unit_warning_errno(UNIT(m), r, "Failed to spawn 'umount' task: %m");
1110 goto fail;
1111 }
1112
1113 mount_set_state(m, MOUNT_UNMOUNTING);
1114
1115 return;
1116
1117 fail:
1118 mount_enter_dead_or_mounted(m, MOUNT_FAILURE_RESOURCES);
1119 }
1120
1121 static int mount_set_mount_command(Mount *m, ExecCommand *c, const MountParameters *p) {
1122 int r;
1123
1124 assert(m);
1125 assert(c);
1126 assert(p);
1127
1128 r = exec_command_set(c, MOUNT_PATH, p->what, m->where, NULL);
1129 if (r < 0)
1130 return r;
1131
1132 if (m->sloppy_options) {
1133 r = exec_command_append(c, "-s", NULL);
1134 if (r < 0)
1135 return r;
1136 }
1137
1138 if (m->read_write_only) {
1139 r = exec_command_append(c, "-w", NULL);
1140 if (r < 0)
1141 return r;
1142 }
1143
1144 if (p->fstype) {
1145 r = exec_command_append(c, "-t", p->fstype, NULL);
1146 if (r < 0)
1147 return r;
1148 }
1149
1150 _cleanup_free_ char *opts = NULL;
1151 r = fstab_filter_options(p->options, "nofail\0" "noauto\0" "auto\0", NULL, NULL, NULL, &opts);
1152 if (r < 0)
1153 return r;
1154
1155 if (!isempty(opts)) {
1156 r = exec_command_append(c, "-o", opts, NULL);
1157 if (r < 0)
1158 return r;
1159 }
1160
1161 return 0;
1162 }
1163
1164 static void mount_enter_mounting(Mount *m) {
1165 int r;
1166 MountParameters *p;
1167 bool source_is_dir = true;
1168
1169 assert(m);
1170
1171 r = unit_fail_if_noncanonical(UNIT(m), m->where);
1172 if (r < 0)
1173 goto fail;
1174
1175 p = get_mount_parameters_fragment(m);
1176 if (p && mount_is_bind(p)) {
1177 r = is_dir(p->what, /* follow = */ true);
1178 if (r < 0 && r != -ENOENT)
1179 log_unit_info_errno(UNIT(m), r, "Failed to determine type of bind mount source '%s', ignoring: %m", p->what);
1180 else if (r == 0)
1181 source_is_dir = false;
1182 }
1183
1184 if (source_is_dir)
1185 r = mkdir_p_label(m->where, m->directory_mode);
1186 else
1187 r = touch_file(m->where, /* parents = */ true, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID);
1188 if (r < 0 && r != -EEXIST)
1189 log_unit_warning_errno(UNIT(m), r, "Failed to create mount point '%s', ignoring: %m", m->where);
1190
1191 if (source_is_dir)
1192 unit_warn_if_dir_nonempty(UNIT(m), m->where);
1193 unit_warn_leftover_processes(UNIT(m), unit_log_leftover_process_start);
1194
1195 m->control_command_id = MOUNT_EXEC_MOUNT;
1196 m->control_command = m->exec_command + MOUNT_EXEC_MOUNT;
1197
1198 /* Create the source directory for bind-mounts if needed */
1199 if (p && mount_is_bind(p)) {
1200 r = mkdir_p_label(p->what, m->directory_mode);
1201 /* mkdir_p_label() can return -EEXIST if the target path exists and is not a directory - which is
1202 * totally OK, in case the user wants us to overmount a non-directory inode. Also -EROFS can be
1203 * returned on read-only filesystem. Moreover, -EACCES (and also maybe -EPERM?) may be returned
1204 * when the path is on NFS. See issue #24120. All such errors will be logged in the debug level. */
1205 if (r < 0 && r != -EEXIST)
1206 log_unit_full_errno(UNIT(m),
1207 (r == -EROFS || ERRNO_IS_PRIVILEGE(r)) ? LOG_DEBUG : LOG_WARNING,
1208 r, "Failed to make bind mount source '%s', ignoring: %m", p->what);
1209 }
1210
1211 if (p) {
1212 r = mount_set_mount_command(m, m->control_command, p);
1213 if (r < 0) {
1214 log_unit_warning_errno(UNIT(m), r, "Failed to prepare mount command line: %m");
1215 goto fail;
1216 }
1217 } else {
1218 r = log_unit_warning_errno(UNIT(m), SYNTHETIC_ERRNO(ENOENT), "No mount parameters to operate on.");
1219 goto fail;
1220 }
1221
1222 mount_unwatch_control_pid(m);
1223
1224 r = mount_spawn(m, m->control_command, &m->control_pid);
1225 if (r < 0) {
1226 log_unit_warning_errno(UNIT(m), r, "Failed to spawn 'mount' task: %m");
1227 goto fail;
1228 }
1229
1230 mount_set_state(m, MOUNT_MOUNTING);
1231 return;
1232
1233 fail:
1234 mount_enter_dead_or_mounted(m, MOUNT_FAILURE_RESOURCES);
1235 }
1236
1237 static void mount_set_reload_result(Mount *m, MountResult result) {
1238 assert(m);
1239
1240 /* Only store the first error we encounter */
1241 if (m->reload_result != MOUNT_SUCCESS)
1242 return;
1243
1244 m->reload_result = result;
1245 }
1246
1247 static void mount_enter_remounting(Mount *m) {
1248 int r;
1249 MountParameters *p;
1250
1251 assert(m);
1252
1253 /* Reset reload result when we are about to start a new remount operation */
1254 m->reload_result = MOUNT_SUCCESS;
1255
1256 m->control_command_id = MOUNT_EXEC_REMOUNT;
1257 m->control_command = m->exec_command + MOUNT_EXEC_REMOUNT;
1258
1259 p = get_mount_parameters_fragment(m);
1260 if (p) {
1261 const char *o;
1262
1263 if (p->options)
1264 o = strjoina("remount,", p->options);
1265 else
1266 o = "remount";
1267
1268 r = exec_command_set(m->control_command, MOUNT_PATH,
1269 p->what, m->where,
1270 "-o", o, NULL);
1271 if (r >= 0 && m->sloppy_options)
1272 r = exec_command_append(m->control_command, "-s", NULL);
1273 if (r >= 0 && m->read_write_only)
1274 r = exec_command_append(m->control_command, "-w", NULL);
1275 if (r >= 0 && p->fstype)
1276 r = exec_command_append(m->control_command, "-t", p->fstype, NULL);
1277 if (r < 0) {
1278 log_unit_warning_errno(UNIT(m), r, "Failed to prepare remount command line: %m");
1279 goto fail;
1280 }
1281
1282 } else {
1283 r = log_unit_warning_errno(UNIT(m), SYNTHETIC_ERRNO(ENOENT), "No mount parameters to operate on.");
1284 goto fail;
1285 }
1286
1287 mount_unwatch_control_pid(m);
1288
1289 r = mount_spawn(m, m->control_command, &m->control_pid);
1290 if (r < 0) {
1291 log_unit_warning_errno(UNIT(m), r, "Failed to spawn 'remount' task: %m");
1292 goto fail;
1293 }
1294
1295 mount_set_state(m, MOUNT_REMOUNTING);
1296 return;
1297
1298 fail:
1299 mount_set_reload_result(m, MOUNT_FAILURE_RESOURCES);
1300 mount_enter_dead_or_mounted(m, MOUNT_SUCCESS);
1301 }
1302
1303 static void mount_cycle_clear(Mount *m) {
1304 assert(m);
1305
1306 /* Clear all state we shall forget for this new cycle */
1307
1308 m->result = MOUNT_SUCCESS;
1309 m->reload_result = MOUNT_SUCCESS;
1310 exec_command_reset_status_array(m->exec_command, _MOUNT_EXEC_COMMAND_MAX);
1311 UNIT(m)->reset_accounting = true;
1312 }
1313
1314 static int mount_start(Unit *u) {
1315 Mount *m = MOUNT(u);
1316 int r;
1317
1318 assert(m);
1319
1320 /* We cannot fulfill this request right now, try again later
1321 * please! */
1322 if (IN_SET(m->state,
1323 MOUNT_UNMOUNTING,
1324 MOUNT_UNMOUNTING_SIGTERM,
1325 MOUNT_UNMOUNTING_SIGKILL,
1326 MOUNT_CLEANING))
1327 return -EAGAIN;
1328
1329 /* Already on it! */
1330 if (IN_SET(m->state, MOUNT_MOUNTING, MOUNT_MOUNTING_DONE))
1331 return 0;
1332
1333 assert(IN_SET(m->state, MOUNT_DEAD, MOUNT_FAILED));
1334
1335 r = unit_acquire_invocation_id(u);
1336 if (r < 0)
1337 return r;
1338
1339 mount_cycle_clear(m);
1340 mount_enter_mounting(m);
1341
1342 return 1;
1343 }
1344
1345 static int mount_stop(Unit *u) {
1346 Mount *m = MOUNT(u);
1347
1348 assert(m);
1349
1350 /* When we directly call umount() for a path, then the state of the corresponding mount unit may be
1351 * outdated. Let's re-read mountinfo now and update the state. */
1352 if (m->invalidated_state)
1353 (void) mount_process_proc_self_mountinfo(u->manager);
1354
1355 switch (m->state) {
1356
1357 case MOUNT_UNMOUNTING:
1358 case MOUNT_UNMOUNTING_SIGKILL:
1359 case MOUNT_UNMOUNTING_SIGTERM:
1360 /* Already on it */
1361 return 0;
1362
1363 case MOUNT_MOUNTING:
1364 case MOUNT_MOUNTING_DONE:
1365 case MOUNT_REMOUNTING:
1366 /* If we are still waiting for /bin/mount, we go directly into kill mode. */
1367 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGTERM, MOUNT_SUCCESS);
1368 return 0;
1369
1370 case MOUNT_REMOUNTING_SIGTERM:
1371 /* If we are already waiting for a hung remount, convert this to the matching unmounting state */
1372 mount_set_state(m, MOUNT_UNMOUNTING_SIGTERM);
1373 return 0;
1374
1375 case MOUNT_REMOUNTING_SIGKILL:
1376 /* as above */
1377 mount_set_state(m, MOUNT_UNMOUNTING_SIGKILL);
1378 return 0;
1379
1380 case MOUNT_MOUNTED:
1381 mount_enter_unmounting(m);
1382 return 1;
1383
1384 case MOUNT_CLEANING:
1385 /* If we are currently cleaning, then abort it, brutally. */
1386 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGKILL, MOUNT_SUCCESS);
1387 return 0;
1388
1389 case MOUNT_DEAD:
1390 case MOUNT_FAILED:
1391 /* The mount has just been unmounted by somebody else. */
1392 return 0;
1393
1394 default:
1395 assert_not_reached();
1396 }
1397 }
1398
1399 static int mount_reload(Unit *u) {
1400 Mount *m = MOUNT(u);
1401
1402 assert(m);
1403 assert(m->state == MOUNT_MOUNTED);
1404
1405 mount_enter_remounting(m);
1406
1407 return 1;
1408 }
1409
1410 static int mount_serialize(Unit *u, FILE *f, FDSet *fds) {
1411 Mount *m = MOUNT(u);
1412
1413 assert(m);
1414 assert(f);
1415 assert(fds);
1416
1417 (void) serialize_item(f, "state", mount_state_to_string(m->state));
1418 (void) serialize_item(f, "result", mount_result_to_string(m->result));
1419 (void) serialize_item(f, "reload-result", mount_result_to_string(m->reload_result));
1420 (void) serialize_item_format(f, "n-retry-umount", "%u", m->n_retry_umount);
1421 (void) serialize_pidref(f, fds, "control-pid", &m->control_pid);
1422
1423 if (m->control_command_id >= 0)
1424 (void) serialize_item(f, "control-command", mount_exec_command_to_string(m->control_command_id));
1425
1426 return 0;
1427 }
1428
1429 static int mount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
1430 Mount *m = MOUNT(u);
1431 int r;
1432
1433 assert(m);
1434 assert(u);
1435 assert(key);
1436 assert(value);
1437 assert(fds);
1438
1439 if (streq(key, "state")) {
1440 MountState state;
1441
1442 state = mount_state_from_string(value);
1443 if (state < 0)
1444 log_unit_debug_errno(u, state, "Failed to parse state value: %s", value);
1445 else
1446 m->deserialized_state = state;
1447
1448 } else if (streq(key, "result")) {
1449 MountResult f;
1450
1451 f = mount_result_from_string(value);
1452 if (f < 0)
1453 log_unit_debug_errno(u, f, "Failed to parse result value: %s", value);
1454 else if (f != MOUNT_SUCCESS)
1455 m->result = f;
1456
1457 } else if (streq(key, "reload-result")) {
1458 MountResult f;
1459
1460 f = mount_result_from_string(value);
1461 if (f < 0)
1462 log_unit_debug_errno(u, f, "Failed to parse reload result value: %s", value);
1463 else if (f != MOUNT_SUCCESS)
1464 m->reload_result = f;
1465
1466 } else if (streq(key, "n-retry-umount")) {
1467
1468 r = safe_atou(value, &m->n_retry_umount);
1469 if (r < 0)
1470 log_unit_debug_errno(u, r, "Failed to parse n-retry-umount value: %s", value);
1471
1472 } else if (streq(key, "control-pid")) {
1473
1474 pidref_done(&m->control_pid);
1475 (void) deserialize_pidref(fds, value, &m->control_pid);
1476
1477 } else if (streq(key, "control-command")) {
1478 MountExecCommand id;
1479
1480 id = mount_exec_command_from_string(value);
1481 if (id < 0)
1482 log_unit_debug_errno(u, id, "Failed to parse exec-command value: %s", value);
1483 else {
1484 m->control_command_id = id;
1485 m->control_command = m->exec_command + id;
1486 }
1487 } else
1488 log_unit_debug(u, "Unknown serialization key: %s", key);
1489
1490 return 0;
1491 }
1492
1493 static UnitActiveState mount_active_state(Unit *u) {
1494 assert(u);
1495
1496 return state_translation_table[MOUNT(u)->state];
1497 }
1498
1499 static const char *mount_sub_state_to_string(Unit *u) {
1500 assert(u);
1501
1502 return mount_state_to_string(MOUNT(u)->state);
1503 }
1504
1505 static bool mount_may_gc(Unit *u) {
1506 Mount *m = MOUNT(u);
1507
1508 assert(m);
1509
1510 if (m->from_proc_self_mountinfo)
1511 return false;
1512
1513 return true;
1514 }
1515
1516 static void mount_sigchld_event(Unit *u, pid_t pid, int code, int status) {
1517 Mount *m = MOUNT(u);
1518 MountResult f;
1519
1520 assert(m);
1521 assert(pid >= 0);
1522
1523 if (pid != m->control_pid.pid)
1524 return;
1525
1526 /* So here's the thing, we really want to know before /usr/bin/mount or /usr/bin/umount exit whether
1527 * they established/remove a mount. This is important when mounting, but even more so when unmounting
1528 * since we need to deal with nested mounts and otherwise cannot safely determine whether to repeat
1529 * the unmounts. In theory, the kernel fires /proc/self/mountinfo changes off before returning from
1530 * the mount() or umount() syscalls, and thus we should see the changes to the proc file before we
1531 * process the waitid() for the /usr/bin/(u)mount processes. However, this is unfortunately racy: we
1532 * have to waitid() for processes using P_ALL (since we need to reap unexpected children that got
1533 * reparented to PID 1), but when using P_ALL we might end up reaping processes that terminated just
1534 * instants ago, i.e. already after our last event loop iteration (i.e. after the last point we might
1535 * have noticed /proc/self/mountinfo events via epoll). This means event loop priorities for
1536 * processing SIGCHLD vs. /proc/self/mountinfo IO events are not as relevant as we want. To fix that
1537 * race, let's explicitly scan /proc/self/mountinfo before we start processing /usr/bin/(u)mount
1538 * dying. It's ugly, but it makes our ordering systematic again, and makes sure we always see
1539 * /proc/self/mountinfo changes before our mount/umount exits. */
1540 (void) mount_process_proc_self_mountinfo(u->manager);
1541
1542 pidref_done(&m->control_pid);
1543
1544 if (is_clean_exit(code, status, EXIT_CLEAN_COMMAND, NULL))
1545 f = MOUNT_SUCCESS;
1546 else if (code == CLD_EXITED)
1547 f = MOUNT_FAILURE_EXIT_CODE;
1548 else if (code == CLD_KILLED)
1549 f = MOUNT_FAILURE_SIGNAL;
1550 else if (code == CLD_DUMPED)
1551 f = MOUNT_FAILURE_CORE_DUMP;
1552 else
1553 assert_not_reached();
1554
1555 if (IN_SET(m->state, MOUNT_REMOUNTING, MOUNT_REMOUNTING_SIGKILL, MOUNT_REMOUNTING_SIGTERM))
1556 mount_set_reload_result(m, f);
1557 else if (m->result == MOUNT_SUCCESS)
1558 m->result = f;
1559
1560 if (m->control_command) {
1561 exec_status_exit(&m->control_command->exec_status, &m->exec_context, pid, code, status);
1562
1563 m->control_command = NULL;
1564 m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
1565 }
1566
1567 unit_log_process_exit(
1568 u,
1569 "Mount process",
1570 mount_exec_command_to_string(m->control_command_id),
1571 f == MOUNT_SUCCESS,
1572 code, status);
1573
1574 /* Note that due to the io event priority logic, we can be sure the new mountinfo is loaded
1575 * before we process the SIGCHLD for the mount command. */
1576
1577 switch (m->state) {
1578
1579 case MOUNT_MOUNTING:
1580 /* Our mount point has not appeared in mountinfo. Something went wrong. */
1581
1582 if (f == MOUNT_SUCCESS) {
1583 /* Either /bin/mount has an unexpected definition of success,
1584 * or someone raced us and we lost. */
1585 log_unit_warning(UNIT(m), "Mount process finished, but there is no mount.");
1586 f = MOUNT_FAILURE_PROTOCOL;
1587 }
1588 mount_enter_dead(m, f);
1589 break;
1590
1591 case MOUNT_MOUNTING_DONE:
1592 mount_enter_mounted(m, f);
1593 break;
1594
1595 case MOUNT_REMOUNTING:
1596 case MOUNT_REMOUNTING_SIGTERM:
1597 case MOUNT_REMOUNTING_SIGKILL:
1598 mount_enter_dead_or_mounted(m, MOUNT_SUCCESS);
1599 break;
1600
1601 case MOUNT_UNMOUNTING:
1602
1603 if (f == MOUNT_SUCCESS && m->from_proc_self_mountinfo) {
1604
1605 /* Still a mount point? If so, let's try again. Most likely there were multiple mount points
1606 * stacked on top of each other. We might exceed the timeout specified by the user overall,
1607 * but we will stop as soon as any one umount times out. */
1608
1609 if (m->n_retry_umount < RETRY_UMOUNT_MAX) {
1610 log_unit_debug(u, "Mount still present, trying again.");
1611 m->n_retry_umount++;
1612 mount_enter_unmounting(m);
1613 } else {
1614 log_unit_warning(u, "Mount still present after %u attempts to unmount, giving up.", m->n_retry_umount);
1615 mount_enter_mounted(m, f);
1616 }
1617 } else
1618 mount_enter_dead_or_mounted(m, f);
1619
1620 break;
1621
1622 case MOUNT_UNMOUNTING_SIGKILL:
1623 case MOUNT_UNMOUNTING_SIGTERM:
1624 mount_enter_dead_or_mounted(m, f);
1625 break;
1626
1627 case MOUNT_CLEANING:
1628 if (m->clean_result == MOUNT_SUCCESS)
1629 m->clean_result = f;
1630
1631 mount_enter_dead(m, MOUNT_SUCCESS);
1632 break;
1633
1634 default:
1635 assert_not_reached();
1636 }
1637
1638 /* Notify clients about changed exit status */
1639 unit_add_to_dbus_queue(u);
1640 }
1641
1642 static int mount_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
1643 Mount *m = MOUNT(userdata);
1644
1645 assert(m);
1646 assert(m->timer_event_source == source);
1647
1648 switch (m->state) {
1649
1650 case MOUNT_MOUNTING:
1651 case MOUNT_MOUNTING_DONE:
1652 log_unit_warning(UNIT(m), "Mounting timed out. Terminating.");
1653 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGTERM, MOUNT_FAILURE_TIMEOUT);
1654 break;
1655
1656 case MOUNT_REMOUNTING:
1657 log_unit_warning(UNIT(m), "Remounting timed out. Terminating remount process.");
1658 mount_set_reload_result(m, MOUNT_FAILURE_TIMEOUT);
1659 mount_enter_signal(m, MOUNT_REMOUNTING_SIGTERM, MOUNT_SUCCESS);
1660 break;
1661
1662 case MOUNT_REMOUNTING_SIGTERM:
1663 mount_set_reload_result(m, MOUNT_FAILURE_TIMEOUT);
1664
1665 if (m->kill_context.send_sigkill) {
1666 log_unit_warning(UNIT(m), "Remounting timed out. Killing.");
1667 mount_enter_signal(m, MOUNT_REMOUNTING_SIGKILL, MOUNT_SUCCESS);
1668 } else {
1669 log_unit_warning(UNIT(m), "Remounting timed out. Skipping SIGKILL. Ignoring.");
1670 mount_enter_dead_or_mounted(m, MOUNT_SUCCESS);
1671 }
1672 break;
1673
1674 case MOUNT_REMOUNTING_SIGKILL:
1675 mount_set_reload_result(m, MOUNT_FAILURE_TIMEOUT);
1676
1677 log_unit_warning(UNIT(m), "Mount process still around after SIGKILL. Ignoring.");
1678 mount_enter_dead_or_mounted(m, MOUNT_SUCCESS);
1679 break;
1680
1681 case MOUNT_UNMOUNTING:
1682 log_unit_warning(UNIT(m), "Unmounting timed out. Terminating.");
1683 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGTERM, MOUNT_FAILURE_TIMEOUT);
1684 break;
1685
1686 case MOUNT_UNMOUNTING_SIGTERM:
1687 if (m->kill_context.send_sigkill) {
1688 log_unit_warning(UNIT(m), "Mount process timed out. Killing.");
1689 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGKILL, MOUNT_FAILURE_TIMEOUT);
1690 } else {
1691 log_unit_warning(UNIT(m), "Mount process timed out. Skipping SIGKILL. Ignoring.");
1692 mount_enter_dead_or_mounted(m, MOUNT_FAILURE_TIMEOUT);
1693 }
1694 break;
1695
1696 case MOUNT_UNMOUNTING_SIGKILL:
1697 log_unit_warning(UNIT(m), "Mount process still around after SIGKILL. Ignoring.");
1698 mount_enter_dead_or_mounted(m, MOUNT_FAILURE_TIMEOUT);
1699 break;
1700
1701 case MOUNT_CLEANING:
1702 log_unit_warning(UNIT(m), "Cleaning timed out. killing.");
1703
1704 if (m->clean_result == MOUNT_SUCCESS)
1705 m->clean_result = MOUNT_FAILURE_TIMEOUT;
1706
1707 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGKILL, 0);
1708 break;
1709
1710 default:
1711 assert_not_reached();
1712 }
1713
1714 return 0;
1715 }
1716
1717 static int mount_setup_new_unit(
1718 Manager *m,
1719 const char *name,
1720 const char *what,
1721 const char *where,
1722 const char *options,
1723 const char *fstype,
1724 MountProcFlags *ret_flags,
1725 Unit **ret) {
1726
1727 _cleanup_(unit_freep) Unit *u = NULL;
1728 int r;
1729
1730 assert(m);
1731 assert(name);
1732 assert(ret_flags);
1733 assert(ret);
1734
1735 r = unit_new_for_name(m, sizeof(Mount), name, &u);
1736 if (r < 0)
1737 return r;
1738
1739 r = free_and_strdup(&u->source_path, "/proc/self/mountinfo");
1740 if (r < 0)
1741 return r;
1742
1743 r = free_and_strdup(&MOUNT(u)->where, where);
1744 if (r < 0)
1745 return r;
1746
1747 r = update_parameters_proc_self_mountinfo(MOUNT(u), what, options, fstype);
1748 if (r < 0)
1749 return r;
1750
1751 /* This unit was generated because /proc/self/mountinfo reported it. Remember this, so that by the
1752 * time we load the unit file for it (and thus add in extra deps right after) we know what source to
1753 * attributes the deps to. */
1754 MOUNT(u)->from_proc_self_mountinfo = true;
1755
1756 r = mount_add_non_exec_dependencies(MOUNT(u));
1757 if (r < 0)
1758 return r;
1759
1760 /* We have only allocated the stub now, let's enqueue this unit for loading now, so that everything
1761 * else is loaded in now. */
1762 unit_add_to_load_queue(u);
1763
1764 *ret_flags = MOUNT_PROC_IS_MOUNTED | MOUNT_PROC_JUST_MOUNTED | MOUNT_PROC_JUST_CHANGED;
1765 *ret = TAKE_PTR(u);
1766 return 0;
1767 }
1768
1769 static int mount_setup_existing_unit(
1770 Unit *u,
1771 const char *what,
1772 const char *where,
1773 const char *options,
1774 const char *fstype,
1775 MountProcFlags *ret_flags) {
1776
1777 int r;
1778
1779 assert(u);
1780 assert(ret_flags);
1781
1782 if (!MOUNT(u)->where) {
1783 MOUNT(u)->where = strdup(where);
1784 if (!MOUNT(u)->where)
1785 return -ENOMEM;
1786 }
1787
1788 /* In case we have multiple mounts established on the same mount point, let's merge flags set already
1789 * for the current unit. Note that the flags field is reset on each iteration of reading
1790 * /proc/self/mountinfo, hence we know for sure anything already set here is from the current
1791 * iteration and thus worthy of taking into account. */
1792 MountProcFlags flags =
1793 MOUNT(u)->proc_flags | MOUNT_PROC_IS_MOUNTED;
1794
1795 r = update_parameters_proc_self_mountinfo(MOUNT(u), what, options, fstype);
1796 if (r < 0)
1797 return r;
1798 if (r > 0)
1799 flags |= MOUNT_PROC_JUST_CHANGED;
1800
1801 /* There are two conditions when we consider a mount point just mounted: when we haven't seen it in
1802 * /proc/self/mountinfo before or when MOUNT_MOUNTING is our current state. Why bother with the
1803 * latter? Shouldn't that be covered by the former? No, during reload it is not because we might then
1804 * encounter a new /proc/self/mountinfo in combination with an old mount unit state (since it stems
1805 * from the serialized state), and need to catch up. Since we know that the MOUNT_MOUNTING state is
1806 * reached when we wait for the mount to appear we hence can assume that if we are in it, we are
1807 * actually seeing it established for the first time. */
1808 if (!MOUNT(u)->from_proc_self_mountinfo || MOUNT(u)->state == MOUNT_MOUNTING)
1809 flags |= MOUNT_PROC_JUST_MOUNTED;
1810
1811 MOUNT(u)->from_proc_self_mountinfo = true;
1812
1813 if (IN_SET(u->load_state, UNIT_NOT_FOUND, UNIT_BAD_SETTING, UNIT_ERROR)) {
1814 /* The unit was previously not found or otherwise not loaded. Now that the unit shows up in
1815 * /proc/self/mountinfo we should reconsider it this, hence set it to UNIT_LOADED. */
1816 u->load_state = UNIT_LOADED;
1817 u->load_error = 0;
1818
1819 flags |= MOUNT_PROC_JUST_CHANGED;
1820 }
1821
1822 if (FLAGS_SET(flags, MOUNT_PROC_JUST_CHANGED)) {
1823 /* If things changed, then make sure that all deps are regenerated. Let's
1824 * first remove all automatic deps, and then add in the new ones. */
1825 r = mount_add_non_exec_dependencies(MOUNT(u));
1826 if (r < 0)
1827 return r;
1828 }
1829
1830 *ret_flags = flags;
1831 return 0;
1832 }
1833
1834 static int mount_setup_unit(
1835 Manager *m,
1836 const char *what,
1837 const char *where,
1838 const char *options,
1839 const char *fstype,
1840 bool set_flags) {
1841
1842 _cleanup_free_ char *e = NULL;
1843 MountProcFlags flags;
1844 Unit *u;
1845 int r;
1846
1847 assert(m);
1848 assert(what);
1849 assert(where);
1850 assert(options);
1851 assert(fstype);
1852
1853 /* Ignore API mount points. They should never be referenced in
1854 * dependencies ever. */
1855 if (mount_point_is_api(where) || mount_point_ignore(where))
1856 return 0;
1857
1858 if (streq(fstype, "autofs"))
1859 return 0;
1860
1861 /* probably some kind of swap, ignore */
1862 if (!is_path(where))
1863 return 0;
1864
1865 r = unit_name_from_path(where, ".mount", &e);
1866 if (r < 0)
1867 return log_struct_errno(
1868 LOG_WARNING, r,
1869 "MESSAGE_ID=" SD_MESSAGE_MOUNT_POINT_PATH_NOT_SUITABLE_STR,
1870 "MOUNT_POINT=%s", where,
1871 LOG_MESSAGE("Failed to generate valid unit name from mount point path '%s', ignoring mount point: %m",
1872 where));
1873
1874 u = manager_get_unit(m, e);
1875 if (u)
1876 r = mount_setup_existing_unit(u, what, where, options, fstype, &flags);
1877 else
1878 /* First time we see this mount point meaning that it's not been initiated by a mount unit
1879 * but rather by the sysadmin having called mount(8) directly. */
1880 r = mount_setup_new_unit(m, e, what, where, options, fstype, &flags, &u);
1881 if (r < 0)
1882 return log_warning_errno(r, "Failed to set up mount unit for '%s': %m", where);
1883
1884 /* If the mount changed properties or state, let's notify our clients */
1885 if (flags & (MOUNT_PROC_JUST_CHANGED|MOUNT_PROC_JUST_MOUNTED))
1886 unit_add_to_dbus_queue(u);
1887
1888 if (set_flags)
1889 MOUNT(u)->proc_flags = flags;
1890
1891 return 0;
1892 }
1893
1894 static int mount_load_proc_self_mountinfo(Manager *m, bool set_flags) {
1895 _cleanup_(mnt_free_tablep) struct libmnt_table *table = NULL;
1896 _cleanup_(mnt_free_iterp) struct libmnt_iter *iter = NULL;
1897 int r;
1898
1899 assert(m);
1900
1901 r = libmount_parse(NULL, NULL, &table, &iter);
1902 if (r < 0)
1903 return log_error_errno(r, "Failed to parse /proc/self/mountinfo: %m");
1904
1905 for (;;) {
1906 struct libmnt_fs *fs;
1907 const char *device, *path, *options, *fstype;
1908
1909 r = mnt_table_next_fs(table, iter, &fs);
1910 if (r == 1)
1911 break;
1912 if (r < 0)
1913 return log_error_errno(r, "Failed to get next entry from /proc/self/mountinfo: %m");
1914
1915 device = mnt_fs_get_source(fs);
1916 path = mnt_fs_get_target(fs);
1917 options = mnt_fs_get_options(fs);
1918 fstype = mnt_fs_get_fstype(fs);
1919
1920 if (!device || !path)
1921 continue;
1922
1923 device_found_node(m, device, DEVICE_FOUND_MOUNT, DEVICE_FOUND_MOUNT);
1924
1925 (void) mount_setup_unit(m, device, path, options, fstype, set_flags);
1926 }
1927
1928 return 0;
1929 }
1930
1931 static void mount_shutdown(Manager *m) {
1932 assert(m);
1933
1934 m->mount_event_source = sd_event_source_disable_unref(m->mount_event_source);
1935
1936 mnt_unref_monitor(m->mount_monitor);
1937 m->mount_monitor = NULL;
1938 }
1939
1940 static int mount_get_timeout(Unit *u, usec_t *timeout) {
1941 Mount *m = MOUNT(u);
1942 usec_t t;
1943 int r;
1944
1945 assert(m);
1946 assert(u);
1947
1948 if (!m->timer_event_source)
1949 return 0;
1950
1951 r = sd_event_source_get_time(m->timer_event_source, &t);
1952 if (r < 0)
1953 return r;
1954 if (t == USEC_INFINITY)
1955 return 0;
1956
1957 *timeout = t;
1958 return 1;
1959 }
1960
1961 static void mount_enumerate_perpetual(Manager *m) {
1962 Unit *u;
1963 int r;
1964
1965 assert(m);
1966
1967 /* Whatever happens, we know for sure that the root directory is around, and cannot go away. Let's
1968 * unconditionally synthesize it here and mark it as perpetual. */
1969
1970 u = manager_get_unit(m, SPECIAL_ROOT_MOUNT);
1971 if (!u) {
1972 r = unit_new_for_name(m, sizeof(Mount), SPECIAL_ROOT_MOUNT, &u);
1973 if (r < 0) {
1974 log_error_errno(r, "Failed to allocate the special " SPECIAL_ROOT_MOUNT " unit: %m");
1975 return;
1976 }
1977 }
1978
1979 u->perpetual = true;
1980 MOUNT(u)->deserialized_state = MOUNT_MOUNTED;
1981
1982 unit_add_to_load_queue(u);
1983 unit_add_to_dbus_queue(u);
1984 }
1985
1986 static bool mount_is_mounted(Mount *m) {
1987 assert(m);
1988
1989 return UNIT(m)->perpetual || FLAGS_SET(m->proc_flags, MOUNT_PROC_IS_MOUNTED);
1990 }
1991
1992 static int mount_on_ratelimit_expire(sd_event_source *s, void *userdata) {
1993 Manager *m = ASSERT_PTR(userdata);
1994 Job *j;
1995
1996 /* Let's enqueue all start jobs that were previously skipped because of active ratelimit. */
1997 HASHMAP_FOREACH(j, m->jobs) {
1998 if (j->unit->type != UNIT_MOUNT)
1999 continue;
2000
2001 job_add_to_run_queue(j);
2002 }
2003
2004 /* By entering ratelimited state we made all mount start jobs not runnable, now rate limit is over so
2005 * let's make sure we dispatch them in the next iteration. */
2006 manager_trigger_run_queue(m);
2007
2008 return 0;
2009 }
2010
2011 static void mount_enumerate(Manager *m) {
2012 int r;
2013
2014 assert(m);
2015
2016 mnt_init_debug(0);
2017
2018 if (!m->mount_monitor) {
2019 unsigned mount_rate_limit_burst = 5;
2020 int fd;
2021
2022 m->mount_monitor = mnt_new_monitor();
2023 if (!m->mount_monitor) {
2024 log_oom();
2025 goto fail;
2026 }
2027
2028 r = mnt_monitor_enable_kernel(m->mount_monitor, 1);
2029 if (r < 0) {
2030 log_error_errno(r, "Failed to enable watching of kernel mount events: %m");
2031 goto fail;
2032 }
2033
2034 r = mnt_monitor_enable_userspace(m->mount_monitor, 1, NULL);
2035 if (r < 0) {
2036 log_error_errno(r, "Failed to enable watching of userspace mount events: %m");
2037 goto fail;
2038 }
2039
2040 /* mnt_unref_monitor() will close the fd */
2041 fd = r = mnt_monitor_get_fd(m->mount_monitor);
2042 if (r < 0) {
2043 log_error_errno(r, "Failed to acquire watch file descriptor: %m");
2044 goto fail;
2045 }
2046
2047 r = sd_event_add_io(m->event, &m->mount_event_source, fd, EPOLLIN, mount_dispatch_io, m);
2048 if (r < 0) {
2049 log_error_errno(r, "Failed to watch mount file descriptor: %m");
2050 goto fail;
2051 }
2052
2053 r = sd_event_source_set_priority(m->mount_event_source, SD_EVENT_PRIORITY_NORMAL-10);
2054 if (r < 0) {
2055 log_error_errno(r, "Failed to adjust mount watch priority: %m");
2056 goto fail;
2057 }
2058
2059 /* Let users override the default (5 in 1s), as it stalls the boot sequence on busy systems. */
2060 const char *e = secure_getenv("SYSTEMD_DEFAULT_MOUNT_RATE_LIMIT_BURST");
2061 if (e) {
2062 r = safe_atou(e, &mount_rate_limit_burst);
2063 if (r < 0)
2064 log_debug("Invalid value in $SYSTEMD_DEFAULT_MOUNT_RATE_LIMIT_BURST, ignoring: %s", e);
2065 }
2066
2067 r = sd_event_source_set_ratelimit(m->mount_event_source, 1 * USEC_PER_SEC, mount_rate_limit_burst);
2068 if (r < 0) {
2069 log_error_errno(r, "Failed to enable rate limit for mount events: %m");
2070 goto fail;
2071 }
2072
2073 r = sd_event_source_set_ratelimit_expire_callback(m->mount_event_source, mount_on_ratelimit_expire);
2074 if (r < 0) {
2075 log_error_errno(r, "Failed to enable rate limit for mount events: %m");
2076 goto fail;
2077 }
2078
2079 (void) sd_event_source_set_description(m->mount_event_source, "mount-monitor-dispatch");
2080 }
2081
2082 r = mount_load_proc_self_mountinfo(m, false);
2083 if (r < 0)
2084 goto fail;
2085
2086 return;
2087
2088 fail:
2089 mount_shutdown(m);
2090 }
2091
2092 static int drain_libmount(Manager *m) {
2093 bool rescan = false;
2094 int r;
2095
2096 assert(m);
2097
2098 /* Drain all events and verify that the event is valid.
2099 *
2100 * Note that libmount also monitors /run/mount mkdir if the directory does not exist yet. The mkdir
2101 * may generate event which is irrelevant for us.
2102 *
2103 * error: r < 0; valid: r == 0, false positive: r == 1 */
2104 do {
2105 r = mnt_monitor_next_change(m->mount_monitor, NULL, NULL);
2106 if (r < 0)
2107 return log_error_errno(r, "Failed to drain libmount events: %m");
2108 if (r == 0)
2109 rescan = true;
2110 } while (r == 0);
2111
2112 return rescan;
2113 }
2114
2115 static int mount_process_proc_self_mountinfo(Manager *m) {
2116 _cleanup_set_free_ Set *around = NULL, *gone = NULL;
2117 const char *what;
2118 int r;
2119
2120 assert(m);
2121
2122 r = drain_libmount(m);
2123 if (r <= 0)
2124 return r;
2125
2126 r = mount_load_proc_self_mountinfo(m, true);
2127 if (r < 0) {
2128 /* Reset flags, just in case, for later calls */
2129 LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_MOUNT])
2130 MOUNT(u)->proc_flags = 0;
2131
2132 return 0;
2133 }
2134
2135 manager_dispatch_load_queue(m);
2136
2137 LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_MOUNT]) {
2138 Mount *mount = MOUNT(u);
2139
2140 mount->invalidated_state = false;
2141
2142 if (!mount_is_mounted(mount)) {
2143
2144 /* A mount point is not around right now. It might be gone, or might never have
2145 * existed. */
2146
2147 if (mount->from_proc_self_mountinfo &&
2148 mount->parameters_proc_self_mountinfo.what)
2149 /* Remember that this device might just have disappeared */
2150 if (set_put_strdup_full(&gone, &path_hash_ops_free, mount->parameters_proc_self_mountinfo.what) < 0)
2151 log_oom(); /* we don't care too much about OOM here... */
2152
2153 mount->from_proc_self_mountinfo = false;
2154 assert_se(update_parameters_proc_self_mountinfo(mount, NULL, NULL, NULL) >= 0);
2155
2156 switch (mount->state) {
2157
2158 case MOUNT_MOUNTED:
2159 /* This has just been unmounted by somebody else, follow the state change. */
2160 mount_enter_dead(mount, MOUNT_SUCCESS);
2161 break;
2162
2163 case MOUNT_MOUNTING_DONE:
2164 /* The mount command may add the corresponding proc mountinfo entry and
2165 * then remove it because of an internal error. E.g., fuse.sshfs seems
2166 * to do that when the connection fails. See #17617. To handle such the
2167 * case, let's once set the state back to mounting. Then, the unit can
2168 * correctly enter the failed state later in mount_sigchld(). */
2169 mount_set_state(mount, MOUNT_MOUNTING);
2170 break;
2171
2172 default:
2173 break;
2174 }
2175
2176 } else if (mount->proc_flags & (MOUNT_PROC_JUST_MOUNTED|MOUNT_PROC_JUST_CHANGED)) {
2177
2178 /* A mount point was added or changed */
2179
2180 switch (mount->state) {
2181
2182 case MOUNT_DEAD:
2183 case MOUNT_FAILED:
2184
2185 /* This has just been mounted by somebody else, follow the state change, but let's
2186 * generate a new invocation ID for this implicitly and automatically. */
2187 (void) unit_acquire_invocation_id(u);
2188 mount_cycle_clear(mount);
2189 mount_enter_mounted(mount, MOUNT_SUCCESS);
2190 break;
2191
2192 case MOUNT_MOUNTING:
2193 mount_set_state(mount, MOUNT_MOUNTING_DONE);
2194 break;
2195
2196 default:
2197 /* Nothing really changed, but let's issue an notification call nonetheless,
2198 * in case somebody is waiting for this. (e.g. file system ro/rw
2199 * remounts.) */
2200 mount_set_state(mount, mount->state);
2201 break;
2202 }
2203 }
2204
2205 if (mount_is_mounted(mount) &&
2206 mount->from_proc_self_mountinfo &&
2207 mount->parameters_proc_self_mountinfo.what)
2208 /* Track devices currently used */
2209 if (set_put_strdup_full(&around, &path_hash_ops_free, mount->parameters_proc_self_mountinfo.what) < 0)
2210 log_oom();
2211
2212 /* Reset the flags for later calls */
2213 mount->proc_flags = 0;
2214 }
2215
2216 SET_FOREACH(what, gone) {
2217 if (set_contains(around, what))
2218 continue;
2219
2220 /* Let the device units know that the device is no longer mounted */
2221 device_found_node(m, what, DEVICE_NOT_FOUND, DEVICE_FOUND_MOUNT);
2222 }
2223
2224 return 0;
2225 }
2226
2227 static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
2228 Manager *m = ASSERT_PTR(userdata);
2229
2230 assert(revents & EPOLLIN);
2231
2232 return mount_process_proc_self_mountinfo(m);
2233 }
2234
2235 int mount_invalidate_state_by_path(Manager *manager, const char *path) {
2236 _cleanup_free_ char *name = NULL;
2237 Unit *u;
2238 int r;
2239
2240 assert(manager);
2241 assert(path);
2242
2243 r = unit_name_from_path(path, ".mount", &name);
2244 if (r < 0)
2245 return log_debug_errno(r, "Failed to generate unit name from path \"%s\", ignoring: %m", path);
2246
2247 u = manager_get_unit(manager, name);
2248 if (!u)
2249 return -ENOENT;
2250
2251 MOUNT(u)->invalidated_state = true;
2252 return 0;
2253 }
2254
2255 static void mount_reset_failed(Unit *u) {
2256 Mount *m = MOUNT(u);
2257
2258 assert(m);
2259
2260 if (m->state == MOUNT_FAILED)
2261 mount_set_state(m, MOUNT_DEAD);
2262
2263 m->result = MOUNT_SUCCESS;
2264 m->reload_result = MOUNT_SUCCESS;
2265 m->clean_result = MOUNT_SUCCESS;
2266 }
2267
2268 static PidRef* mount_control_pid(Unit *u) {
2269 return &ASSERT_PTR(MOUNT(u))->control_pid;
2270 }
2271
2272 static int mount_clean(Unit *u, ExecCleanMask mask) {
2273 _cleanup_strv_free_ char **l = NULL;
2274 Mount *m = MOUNT(u);
2275 int r;
2276
2277 assert(m);
2278 assert(mask != 0);
2279
2280 if (m->state != MOUNT_DEAD)
2281 return -EBUSY;
2282
2283 r = exec_context_get_clean_directories(&m->exec_context, u->manager->prefix, mask, &l);
2284 if (r < 0)
2285 return r;
2286
2287 if (strv_isempty(l))
2288 return -EUNATCH;
2289
2290 mount_unwatch_control_pid(m);
2291 m->clean_result = MOUNT_SUCCESS;
2292 m->control_command = NULL;
2293 m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
2294
2295 r = mount_arm_timer(m, /* relative= */ true, m->exec_context.timeout_clean_usec);
2296 if (r < 0) {
2297 log_unit_warning_errno(u, r, "Failed to install timer: %m");
2298 goto fail;
2299 }
2300
2301 r = unit_fork_and_watch_rm_rf(u, l, &m->control_pid);
2302 if (r < 0) {
2303 log_unit_warning_errno(u, r, "Failed to spawn cleaning task: %m");
2304 goto fail;
2305 }
2306
2307 mount_set_state(m, MOUNT_CLEANING);
2308 return 0;
2309
2310 fail:
2311 m->clean_result = MOUNT_FAILURE_RESOURCES;
2312 m->timer_event_source = sd_event_source_disable_unref(m->timer_event_source);
2313 return r;
2314 }
2315
2316 static int mount_can_clean(Unit *u, ExecCleanMask *ret) {
2317 Mount *m = MOUNT(u);
2318
2319 assert(m);
2320
2321 return exec_context_get_clean_mask(&m->exec_context, ret);
2322 }
2323
2324 static int mount_can_start(Unit *u) {
2325 Mount *m = MOUNT(u);
2326 int r;
2327
2328 assert(m);
2329
2330 r = unit_test_start_limit(u);
2331 if (r < 0) {
2332 mount_enter_dead(m, MOUNT_FAILURE_START_LIMIT_HIT);
2333 return r;
2334 }
2335
2336 return 1;
2337 }
2338
2339 static int mount_subsystem_ratelimited(Manager *m) {
2340 assert(m);
2341
2342 if (!m->mount_event_source)
2343 return false;
2344
2345 return sd_event_source_is_ratelimited(m->mount_event_source);
2346 }
2347
2348 static const char* const mount_exec_command_table[_MOUNT_EXEC_COMMAND_MAX] = {
2349 [MOUNT_EXEC_MOUNT] = "ExecMount",
2350 [MOUNT_EXEC_UNMOUNT] = "ExecUnmount",
2351 [MOUNT_EXEC_REMOUNT] = "ExecRemount",
2352 };
2353
2354 DEFINE_STRING_TABLE_LOOKUP(mount_exec_command, MountExecCommand);
2355
2356 static const char* const mount_result_table[_MOUNT_RESULT_MAX] = {
2357 [MOUNT_SUCCESS] = "success",
2358 [MOUNT_FAILURE_RESOURCES] = "resources",
2359 [MOUNT_FAILURE_TIMEOUT] = "timeout",
2360 [MOUNT_FAILURE_EXIT_CODE] = "exit-code",
2361 [MOUNT_FAILURE_SIGNAL] = "signal",
2362 [MOUNT_FAILURE_CORE_DUMP] = "core-dump",
2363 [MOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
2364 [MOUNT_FAILURE_PROTOCOL] = "protocol",
2365 };
2366
2367 DEFINE_STRING_TABLE_LOOKUP(mount_result, MountResult);
2368
2369 const UnitVTable mount_vtable = {
2370 .object_size = sizeof(Mount),
2371 .exec_context_offset = offsetof(Mount, exec_context),
2372 .cgroup_context_offset = offsetof(Mount, cgroup_context),
2373 .kill_context_offset = offsetof(Mount, kill_context),
2374 .exec_runtime_offset = offsetof(Mount, exec_runtime),
2375
2376 .sections =
2377 "Unit\0"
2378 "Mount\0"
2379 "Install\0",
2380 .private_section = "Mount",
2381
2382 .can_transient = true,
2383 .can_fail = true,
2384 .exclude_from_switch_root_serialization = true,
2385
2386 .init = mount_init,
2387 .load = mount_load,
2388 .done = mount_done,
2389
2390 .coldplug = mount_coldplug,
2391 .catchup = mount_catchup,
2392
2393 .dump = mount_dump,
2394
2395 .start = mount_start,
2396 .stop = mount_stop,
2397 .reload = mount_reload,
2398
2399 .clean = mount_clean,
2400 .can_clean = mount_can_clean,
2401
2402 .serialize = mount_serialize,
2403 .deserialize_item = mount_deserialize_item,
2404
2405 .active_state = mount_active_state,
2406 .sub_state_to_string = mount_sub_state_to_string,
2407
2408 .will_restart = unit_will_restart_default,
2409
2410 .may_gc = mount_may_gc,
2411 .is_extrinsic = mount_is_extrinsic,
2412
2413 .sigchld_event = mount_sigchld_event,
2414
2415 .reset_failed = mount_reset_failed,
2416
2417 .control_pid = mount_control_pid,
2418
2419 .bus_set_property = bus_mount_set_property,
2420 .bus_commit_properties = bus_mount_commit_properties,
2421
2422 .get_timeout = mount_get_timeout,
2423
2424 .enumerate_perpetual = mount_enumerate_perpetual,
2425 .enumerate = mount_enumerate,
2426 .shutdown = mount_shutdown,
2427 .subsystem_ratelimited = mount_subsystem_ratelimited,
2428
2429 .status_message_formats = {
2430 .starting_stopping = {
2431 [0] = "Mounting %s...",
2432 [1] = "Unmounting %s...",
2433 },
2434 .finished_start_job = {
2435 [JOB_DONE] = "Mounted %s.",
2436 [JOB_FAILED] = "Failed to mount %s.",
2437 [JOB_TIMEOUT] = "Timed out mounting %s.",
2438 },
2439 .finished_stop_job = {
2440 [JOB_DONE] = "Unmounted %s.",
2441 [JOB_FAILED] = "Failed unmounting %s.",
2442 [JOB_TIMEOUT] = "Timed out unmounting %s.",
2443 },
2444 },
2445
2446 .can_start = mount_can_start,
2447
2448 .notify_plymouth = true,
2449 };
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