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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 bool mount_is_bound_to_device(Mount *m) {
129 const MountParameters *p;
130
131 assert(m);
132
133 /* Determines whether to place a Requires= or BindsTo= dependency on the backing device unit. We do
134 * this by checking for the x-systemd.device-bound mount option. Iff it is set we use BindsTo=,
135 * otherwise Requires=. But note that we might combine the latter with StopPropagatedFrom=, see
136 * below. */
137
138 p = get_mount_parameters(m);
139 if (!p)
140 return false;
141
142 return fstab_test_option(p->options, "x-systemd.device-bound\0");
143 }
144
145 static bool mount_propagate_stop(Mount *m) {
146 assert(m);
147
148 if (mount_is_bound_to_device(m)) /* If we are using BindsTo= the stop propagation is implicit, no need to bother */
149 return false;
150
151 return m->from_fragment; /* let's propagate stop whenever this is an explicitly configured unit,
152 * otherwise let's not bother. */
153 }
154
155 static bool mount_needs_quota(const MountParameters *p) {
156 assert(p);
157
158 if (p->fstype && !fstype_needs_quota(p->fstype))
159 return false;
160
161 if (mount_is_bind(p))
162 return false;
163
164 return fstab_test_option(p->options,
165 "usrquota\0" "grpquota\0" "quota\0" "usrjquota\0" "grpjquota\0");
166 }
167
168 static void mount_init(Unit *u) {
169 Mount *m = MOUNT(u);
170
171 assert(m);
172 assert(u);
173 assert(u->load_state == UNIT_STUB);
174
175 m->timeout_usec = u->manager->defaults.timeout_start_usec;
176
177 m->exec_context.std_output = u->manager->defaults.std_output;
178 m->exec_context.std_error = u->manager->defaults.std_error;
179
180 m->directory_mode = 0755;
181
182 /* We need to make sure that /usr/bin/mount is always called
183 * in the same process group as us, so that the autofs kernel
184 * side doesn't send us another mount request while we are
185 * already trying to comply its last one. */
186 m->exec_context.same_pgrp = true;
187
188 m->control_pid = PIDREF_NULL;
189 m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
190
191 u->ignore_on_isolate = true;
192 }
193
194 static int mount_arm_timer(Mount *m, usec_t usec) {
195 int r;
196
197 assert(m);
198
199 if (usec == USEC_INFINITY)
200 return sd_event_source_set_enabled(m->timer_event_source, SD_EVENT_OFF);
201
202 if (m->timer_event_source) {
203 r = sd_event_source_set_time(m->timer_event_source, usec);
204 if (r < 0)
205 return r;
206
207 return sd_event_source_set_enabled(m->timer_event_source, SD_EVENT_ONESHOT);
208 }
209
210 r = sd_event_add_time(
211 UNIT(m)->manager->event,
212 &m->timer_event_source,
213 CLOCK_MONOTONIC,
214 usec, 0,
215 mount_dispatch_timer, m);
216 if (r < 0)
217 return r;
218
219 (void) sd_event_source_set_description(m->timer_event_source, "mount-timer");
220
221 return 0;
222 }
223
224 static void mount_unwatch_control_pid(Mount *m) {
225 assert(m);
226
227 if (!pidref_is_set(&m->control_pid))
228 return;
229
230 unit_unwatch_pid(UNIT(m), m->control_pid.pid);
231 pidref_done(&m->control_pid);
232 }
233
234 static void mount_parameters_done(MountParameters *p) {
235 assert(p);
236
237 p->what = mfree(p->what);
238 p->options = mfree(p->options);
239 p->fstype = mfree(p->fstype);
240 }
241
242 static void mount_done(Unit *u) {
243 Mount *m = MOUNT(u);
244
245 assert(m);
246
247 m->where = mfree(m->where);
248
249 mount_parameters_done(&m->parameters_proc_self_mountinfo);
250 mount_parameters_done(&m->parameters_fragment);
251
252 m->exec_runtime = exec_runtime_free(m->exec_runtime);
253 exec_command_done_array(m->exec_command, _MOUNT_EXEC_COMMAND_MAX);
254 m->control_command = NULL;
255
256 mount_unwatch_control_pid(m);
257
258 m->timer_event_source = sd_event_source_disable_unref(m->timer_event_source);
259 }
260
261 static int update_parameters_proc_self_mountinfo(
262 Mount *m,
263 const char *what,
264 const char *options,
265 const char *fstype) {
266
267 MountParameters *p;
268 int r, q, w;
269
270 p = &m->parameters_proc_self_mountinfo;
271
272 r = free_and_strdup(&p->what, what);
273 if (r < 0)
274 return r;
275
276 q = free_and_strdup(&p->options, options);
277 if (q < 0)
278 return q;
279
280 w = free_and_strdup(&p->fstype, fstype);
281 if (w < 0)
282 return w;
283
284 return r > 0 || q > 0 || w > 0;
285 }
286
287 static int mount_add_mount_dependencies(Mount *m) {
288 MountParameters *pm;
289 Unit *other;
290 Set *s;
291 int r;
292
293 assert(m);
294
295 if (!path_equal(m->where, "/")) {
296 _cleanup_free_ char *parent = NULL;
297
298 /* Adds in links to other mount points that might lie further up in the hierarchy */
299
300 r = path_extract_directory(m->where, &parent);
301 if (r < 0)
302 return r;
303
304 r = unit_require_mounts_for(UNIT(m), parent, UNIT_DEPENDENCY_IMPLICIT);
305 if (r < 0)
306 return r;
307 }
308
309 /* Adds in dependencies to other mount points that might be needed for the source path (if this is a bind mount
310 * or a loop mount) to be available. */
311 pm = get_mount_parameters_fragment(m);
312 if (pm && pm->what &&
313 path_is_absolute(pm->what) &&
314 (mount_is_bind(pm) || mount_is_loop(pm) || !mount_is_network(pm))) {
315
316 r = unit_require_mounts_for(UNIT(m), pm->what, UNIT_DEPENDENCY_FILE);
317 if (r < 0)
318 return r;
319 }
320
321 /* Adds in dependencies to other units that use this path or paths further down in the hierarchy */
322 s = manager_get_units_requiring_mounts_for(UNIT(m)->manager, m->where);
323 SET_FOREACH(other, s) {
324
325 if (other->load_state != UNIT_LOADED)
326 continue;
327
328 if (other == UNIT(m))
329 continue;
330
331 r = unit_add_dependency(other, UNIT_AFTER, UNIT(m), true, UNIT_DEPENDENCY_PATH);
332 if (r < 0)
333 return r;
334
335 if (UNIT(m)->fragment_path) {
336 /* If we have fragment configuration, then make this dependency required */
337 r = unit_add_dependency(other, UNIT_REQUIRES, UNIT(m), true, UNIT_DEPENDENCY_PATH);
338 if (r < 0)
339 return r;
340 }
341 }
342
343 return 0;
344 }
345
346 static int mount_add_device_dependencies(Mount *m) {
347 UnitDependencyMask mask;
348 MountParameters *p;
349 UnitDependency dep;
350 int r;
351
352 assert(m);
353
354 log_unit_trace(UNIT(m), "Processing implicit device dependencies");
355
356 p = get_mount_parameters(m);
357 if (!p) {
358 log_unit_trace(UNIT(m), "Missing mount parameters, skipping implicit device dependencies");
359 return 0;
360 }
361
362 if (!p->what) {
363 log_unit_trace(UNIT(m), "Missing mount source, skipping implicit device dependencies");
364 return 0;
365 }
366
367 if (mount_is_bind(p)) {
368 log_unit_trace(UNIT(m), "Mount unit is a bind mount, skipping implicit device dependencies");
369 return 0;
370 }
371
372 if (!is_device_path(p->what)) {
373 log_unit_trace(UNIT(m), "Mount source is not a device path, skipping implicit device dependencies");
374 return 0;
375 }
376
377 /* /dev/root is a really weird thing, it's not a real device, but just a path the kernel exports for
378 * the root file system specified on the kernel command line. Ignore it here. */
379 if (PATH_IN_SET(p->what, "/dev/root", "/dev/nfs")) {
380 log_unit_trace(UNIT(m), "Mount source is in /dev/root or /dev/nfs, skipping implicit device dependencies");
381 return 0;
382 }
383
384 if (path_equal(m->where, "/")) {
385 log_unit_trace(UNIT(m), "Mount destination is '/', skipping implicit device dependencies");
386 return 0;
387 }
388
389 /* Mount units from /proc/self/mountinfo are not bound to devices by default since they're subject to
390 * races when mounts are established by other tools with different backing devices than what we
391 * maintain. The user can still force this to be a BindsTo= dependency with an appropriate option (or
392 * udev property) so the mount units are automatically stopped when the device disappears
393 * suddenly. */
394 dep = mount_is_bound_to_device(m) ? UNIT_BINDS_TO : UNIT_REQUIRES;
395
396 /* We always use 'what' from /proc/self/mountinfo if mounted */
397 mask = m->from_proc_self_mountinfo ? UNIT_DEPENDENCY_MOUNTINFO : UNIT_DEPENDENCY_MOUNT_FILE;
398
399 r = unit_add_node_dependency(UNIT(m), p->what, dep, mask);
400 if (r < 0)
401 return r;
402 if (r > 0)
403 log_unit_trace(UNIT(m), "Added %s dependency on %s", unit_dependency_to_string(dep), p->what);
404
405 if (mount_propagate_stop(m)) {
406 r = unit_add_node_dependency(UNIT(m), p->what, UNIT_STOP_PROPAGATED_FROM, mask);
407 if (r < 0)
408 return r;
409 if (r > 0)
410 log_unit_trace(UNIT(m), "Added %s dependency on %s",
411 unit_dependency_to_string(UNIT_STOP_PROPAGATED_FROM), p->what);
412 }
413
414 r = unit_add_blockdev_dependency(UNIT(m), p->what, mask);
415 if (r > 0)
416 log_unit_trace(UNIT(m), "Added %s dependency on %s", unit_dependency_to_string(UNIT_AFTER), p->what);
417
418 return 0;
419 }
420
421 static int mount_add_quota_dependencies(Mount *m) {
422 MountParameters *p;
423 int r;
424
425 assert(m);
426
427 if (!MANAGER_IS_SYSTEM(UNIT(m)->manager))
428 return 0;
429
430 p = get_mount_parameters_fragment(m);
431 if (!p)
432 return 0;
433
434 if (!mount_needs_quota(p))
435 return 0;
436
437 r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_WANTS, SPECIAL_QUOTACHECK_SERVICE,
438 /* add_reference= */ true, UNIT_DEPENDENCY_FILE);
439 if (r < 0)
440 return r;
441
442 r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_WANTS, SPECIAL_QUOTAON_SERVICE,
443 /* add_reference= */true, UNIT_DEPENDENCY_FILE);
444 if (r < 0)
445 return r;
446
447 return 0;
448 }
449
450 static bool mount_is_extrinsic(Unit *u) {
451 MountParameters *p;
452 Mount *m = MOUNT(u);
453 assert(m);
454
455 /* Returns true for all units that are "magic" and should be excluded from the usual
456 * start-up and shutdown dependencies. We call them "extrinsic" here, as they are generally
457 * mounted outside of the systemd dependency logic. We shouldn't attempt to manage them
458 * ourselves but it's fine if the user operates on them with us. */
459
460 /* We only automatically manage mounts if we are in system mode */
461 if (MANAGER_IS_USER(u->manager))
462 return true;
463
464 p = get_mount_parameters(m);
465 if (p && fstab_is_extrinsic(m->where, p->options))
466 return true;
467
468 return false;
469 }
470
471 static bool mount_is_credentials(Mount *m) {
472 const char *e;
473
474 assert(m);
475
476 /* Returns true if this is a credentials mount. We don't want automatic dependencies on credential
477 * mounts, since they are managed by us for even the earliest services, and we never want anything to
478 * be ordered before them hence. */
479
480 e = path_startswith(m->where, UNIT(m)->manager->prefix[EXEC_DIRECTORY_RUNTIME]);
481 if (!e)
482 return false;
483
484 return !isempty(path_startswith(e, "credentials"));
485 }
486
487 static int mount_add_default_ordering_dependencies(Mount *m, MountParameters *p, UnitDependencyMask mask) {
488 const char *after, *before, *e;
489 int r;
490
491 assert(m);
492
493 e = path_startswith(m->where, "/sysroot");
494 if (e && in_initrd()) {
495 /* All mounts under /sysroot need to happen later, at initrd-fs.target time. IOW,
496 * it's not technically part of the basic initrd filesystem itself, and so
497 * shouldn't inherit the default Before=local-fs.target dependency. However,
498 * these mounts still need to start after local-fs-pre.target, as a sync point
499 * for things like systemd-hibernate-resume.service that should start before
500 * any mounts. */
501
502 after = SPECIAL_LOCAL_FS_PRE_TARGET;
503 before = isempty(e) ? SPECIAL_INITRD_ROOT_FS_TARGET : SPECIAL_INITRD_FS_TARGET;
504
505 } else if (in_initrd() && path_startswith(m->where, "/sysusr/usr")) {
506 after = SPECIAL_LOCAL_FS_PRE_TARGET;
507 before = SPECIAL_INITRD_USR_FS_TARGET;
508
509 } else if (mount_is_credentials(m))
510 after = before = NULL;
511
512 else if (mount_is_network(p)) {
513 after = SPECIAL_REMOTE_FS_PRE_TARGET;
514 before = SPECIAL_REMOTE_FS_TARGET;
515
516 } else {
517 after = SPECIAL_LOCAL_FS_PRE_TARGET;
518 before = SPECIAL_LOCAL_FS_TARGET;
519 }
520
521 if (before && !mount_is_nofail(m)) {
522 r = unit_add_dependency_by_name(UNIT(m), UNIT_BEFORE, before, /* add_reference= */ true, mask);
523 if (r < 0)
524 return r;
525 }
526
527 if (after) {
528 r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, after, /* add_reference= */ true, mask);
529 if (r < 0)
530 return r;
531 }
532
533 r = unit_add_two_dependencies_by_name(UNIT(m), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET,
534 /* add_reference= */ true, mask);
535 if (r < 0)
536 return r;
537
538 /* If this is a tmpfs mount then we have to unmount it before we try to deactivate swaps */
539 if (streq_ptr(p->fstype, "tmpfs") && !mount_is_credentials(m)) {
540 r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, SPECIAL_SWAP_TARGET,
541 /* add_reference= */ true, mask);
542 if (r < 0)
543 return r;
544 }
545
546 return 0;
547 }
548
549 static int mount_add_default_network_dependencies(Mount *m, MountParameters *p, UnitDependencyMask mask) {
550 int r;
551
552 assert(m);
553
554 if (!mount_is_network(p))
555 return 0;
556
557 /* We order ourselves after network.target. This is primarily useful at shutdown: services that take
558 * down the network should order themselves before network.target, so that they are shut down only
559 * after this mount unit is stopped. */
560
561 r = unit_add_dependency_by_name(UNIT(m), UNIT_AFTER, SPECIAL_NETWORK_TARGET,
562 /* add_reference= */ true, mask);
563 if (r < 0)
564 return r;
565
566 /* We pull in network-online.target, and order ourselves after it. This is useful at start-up to
567 * actively pull in tools that want to be started before we start mounting network file systems, and
568 * whose purpose it is to delay this until the network is "up". */
569
570 return unit_add_two_dependencies_by_name(UNIT(m), UNIT_WANTS, UNIT_AFTER, SPECIAL_NETWORK_ONLINE_TARGET,
571 /* add_reference= */ true, mask);
572 }
573
574 static int mount_add_default_dependencies(Mount *m) {
575 UnitDependencyMask mask;
576 MountParameters *p;
577 int r;
578
579 assert(m);
580
581 if (!UNIT(m)->default_dependencies)
582 return 0;
583
584 /* We do not add any default dependencies to /, /usr or /run/initramfs/, since they are
585 * guaranteed to stay mounted the whole time, since our system is on it. Also, don't
586 * bother with anything mounted below virtual file systems, it's also going to be virtual,
587 * and hence not worth the effort. */
588 if (mount_is_extrinsic(UNIT(m)))
589 return 0;
590
591 p = get_mount_parameters(m);
592 if (!p)
593 return 0;
594
595 mask = m->from_proc_self_mountinfo ? UNIT_DEPENDENCY_MOUNTINFO : UNIT_DEPENDENCY_MOUNT_FILE;
596
597 r = mount_add_default_ordering_dependencies(m, p, mask);
598 if (r < 0)
599 return r;
600
601 r = mount_add_default_network_dependencies(m, p, mask);
602 if (r < 0)
603 return r;
604
605 return 0;
606 }
607
608 static int mount_verify(Mount *m) {
609 _cleanup_free_ char *e = NULL;
610 MountParameters *p;
611 int r;
612
613 assert(m);
614 assert(UNIT(m)->load_state == UNIT_LOADED);
615
616 if (!m->from_fragment && !m->from_proc_self_mountinfo && !UNIT(m)->perpetual)
617 return -ENOENT;
618
619 r = unit_name_from_path(m->where, ".mount", &e);
620 if (r < 0)
621 return log_unit_error_errno(UNIT(m), r, "Failed to generate unit name from mount path: %m");
622
623 if (!unit_has_name(UNIT(m), e))
624 return log_unit_error_errno(UNIT(m), SYNTHETIC_ERRNO(ENOEXEC), "Where= setting doesn't match unit name. Refusing.");
625
626 if (mount_point_is_api(m->where) || mount_point_ignore(m->where))
627 return log_unit_error_errno(UNIT(m), SYNTHETIC_ERRNO(ENOEXEC), "Cannot create mount unit for API file system %s. Refusing.", m->where);
628
629 p = get_mount_parameters_fragment(m);
630 if (p && !p->what && !UNIT(m)->perpetual)
631 return log_unit_error_errno(UNIT(m), SYNTHETIC_ERRNO(ENOEXEC),
632 "What= setting is missing. Refusing.");
633
634 if (m->exec_context.pam_name && m->kill_context.kill_mode != KILL_CONTROL_GROUP)
635 return log_unit_error_errno(UNIT(m), SYNTHETIC_ERRNO(ENOEXEC), "Unit has PAM enabled. Kill mode must be set to control-group'. Refusing.");
636
637 return 0;
638 }
639
640 static int mount_add_non_exec_dependencies(Mount *m) {
641 int r;
642
643 assert(m);
644
645 /* We may be called due to this mount appearing in /proc/self/mountinfo, hence we clear all existing
646 * dependencies that were initialized from the unit file but whose final value really depends on the
647 * content of /proc/self/mountinfo. Some (such as m->where) might have become stale now. */
648 unit_remove_dependencies(UNIT(m), UNIT_DEPENDENCY_MOUNTINFO | UNIT_DEPENDENCY_MOUNT_FILE);
649
650 if (!m->where)
651 return 0;
652
653 /* Adds in all dependencies directly responsible for ordering the mount, as opposed to dependencies
654 * resulting from the ExecContext and such. */
655
656 r = mount_add_device_dependencies(m);
657 if (r < 0)
658 return r;
659
660 r = mount_add_mount_dependencies(m);
661 if (r < 0)
662 return r;
663
664 r = mount_add_quota_dependencies(m);
665 if (r < 0)
666 return r;
667
668 r = mount_add_default_dependencies(m);
669 if (r < 0)
670 return r;
671
672 return 0;
673 }
674
675 static int mount_add_extras(Mount *m) {
676 Unit *u = UNIT(m);
677 int r;
678
679 assert(m);
680
681 /* Note: this call might be called after we already have been loaded once (and even when it has already been
682 * activated), in case data from /proc/self/mountinfo has changed. This means all code here needs to be ready
683 * to run with an already set up unit. */
684
685 if (u->fragment_path)
686 m->from_fragment = true;
687
688 if (!m->where) {
689 r = unit_name_to_path(u->id, &m->where);
690 if (r == -ENAMETOOLONG)
691 log_unit_error_errno(u, r, "Failed to derive mount point path from unit name, because unit name is hashed. "
692 "Set \"Where=\" in the unit file explicitly.");
693 if (r < 0)
694 return r;
695 }
696
697 path_simplify(m->where);
698
699 if (!u->description) {
700 r = unit_set_description(u, m->where);
701 if (r < 0)
702 return r;
703 }
704
705 r = unit_patch_contexts(u);
706 if (r < 0)
707 return r;
708
709 r = unit_add_exec_dependencies(u, &m->exec_context);
710 if (r < 0)
711 return r;
712
713 r = unit_set_default_slice(u);
714 if (r < 0)
715 return r;
716
717 r = mount_add_non_exec_dependencies(m);
718 if (r < 0)
719 return r;
720
721 return 0;
722 }
723
724 static void mount_load_root_mount(Unit *u) {
725 assert(u);
726
727 if (!unit_has_name(u, SPECIAL_ROOT_MOUNT))
728 return;
729
730 u->perpetual = true;
731 u->default_dependencies = false;
732
733 /* The stdio/kmsg bridge socket is on /, in order to avoid a dep loop, don't use kmsg logging for -.mount */
734 MOUNT(u)->exec_context.std_output = EXEC_OUTPUT_NULL;
735 MOUNT(u)->exec_context.std_input = EXEC_INPUT_NULL;
736
737 if (!u->description)
738 u->description = strdup("Root Mount");
739 }
740
741 static int mount_load(Unit *u) {
742 Mount *m = MOUNT(u);
743 int r, q = 0;
744
745 assert(m);
746 assert(u);
747 assert(u->load_state == UNIT_STUB);
748
749 mount_load_root_mount(u);
750
751 bool fragment_optional = m->from_proc_self_mountinfo || u->perpetual;
752 r = unit_load_fragment_and_dropin(u, !fragment_optional);
753
754 /* Add in some extras. Note we do this in all cases (even if we failed to load the unit) when announced by the
755 * kernel, because we need some things to be set up no matter what when the kernel establishes a mount and thus
756 * we need to update the state in our unit to track it. After all, consider that we don't allow changing the
757 * 'slice' field for a unit once it is active. */
758 if (u->load_state == UNIT_LOADED || m->from_proc_self_mountinfo || u->perpetual)
759 q = mount_add_extras(m);
760
761 if (r < 0)
762 return r;
763 if (q < 0)
764 return q;
765 if (u->load_state != UNIT_LOADED)
766 return 0;
767
768 return mount_verify(m);
769 }
770
771 static void mount_set_state(Mount *m, MountState state) {
772 MountState old_state;
773 assert(m);
774
775 if (m->state != state)
776 bus_unit_send_pending_change_signal(UNIT(m), false);
777
778 old_state = m->state;
779 m->state = state;
780
781 if (!MOUNT_STATE_WITH_PROCESS(state)) {
782 m->timer_event_source = sd_event_source_disable_unref(m->timer_event_source);
783 mount_unwatch_control_pid(m);
784 m->control_command = NULL;
785 m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
786 }
787
788 if (state != old_state)
789 log_unit_debug(UNIT(m), "Changed %s -> %s", mount_state_to_string(old_state), mount_state_to_string(state));
790
791 unit_notify(UNIT(m), state_translation_table[old_state], state_translation_table[state], m->reload_result == MOUNT_SUCCESS);
792 }
793
794 static int mount_coldplug(Unit *u) {
795 Mount *m = MOUNT(u);
796 int r;
797
798 assert(m);
799 assert(m->state == MOUNT_DEAD);
800
801 if (m->deserialized_state == m->state)
802 return 0;
803
804 if (pidref_is_set(&m->control_pid) &&
805 pid_is_unwaited(m->control_pid.pid) &&
806 MOUNT_STATE_WITH_PROCESS(m->deserialized_state)) {
807
808 r = unit_watch_pid(UNIT(m), m->control_pid.pid, /* exclusive= */ false);
809 if (r < 0)
810 return r;
811
812 r = mount_arm_timer(m, usec_add(u->state_change_timestamp.monotonic, m->timeout_usec));
813 if (r < 0)
814 return r;
815 }
816
817 if (!IN_SET(m->deserialized_state, MOUNT_DEAD, MOUNT_FAILED))
818 (void) unit_setup_exec_runtime(u);
819
820 mount_set_state(m, m->deserialized_state);
821 return 0;
822 }
823
824 static void mount_catchup(Unit *u) {
825 Mount *m = MOUNT(ASSERT_PTR(u));
826
827 assert(m);
828
829 /* Adjust the deserialized state. See comments in mount_process_proc_self_mountinfo(). */
830 if (m->from_proc_self_mountinfo)
831 switch (m->state) {
832 case MOUNT_DEAD:
833 case MOUNT_FAILED:
834 assert(!pidref_is_set(&m->control_pid));
835 (void) unit_acquire_invocation_id(u);
836 mount_cycle_clear(m);
837 mount_enter_mounted(m, MOUNT_SUCCESS);
838 break;
839 case MOUNT_MOUNTING:
840 assert(pidref_is_set(&m->control_pid));
841 mount_set_state(m, MOUNT_MOUNTING_DONE);
842 break;
843 default:
844 break;
845 }
846 else
847 switch (m->state) {
848 case MOUNT_MOUNTING_DONE:
849 assert(pidref_is_set(&m->control_pid));
850 mount_set_state(m, MOUNT_MOUNTING);
851 break;
852 case MOUNT_MOUNTED:
853 assert(!pidref_is_set(&m->control_pid));
854 mount_enter_dead(m, MOUNT_SUCCESS);
855 break;
856 default:
857 break;
858 }
859 }
860
861 static void mount_dump(Unit *u, FILE *f, const char *prefix) {
862 Mount *m = MOUNT(u);
863 MountParameters *p;
864
865 assert(m);
866 assert(f);
867
868 p = get_mount_parameters(m);
869
870 fprintf(f,
871 "%sMount State: %s\n"
872 "%sResult: %s\n"
873 "%sClean Result: %s\n"
874 "%sWhere: %s\n"
875 "%sWhat: %s\n"
876 "%sFile System Type: %s\n"
877 "%sOptions: %s\n"
878 "%sFrom /proc/self/mountinfo: %s\n"
879 "%sFrom fragment: %s\n"
880 "%sExtrinsic: %s\n"
881 "%sDirectoryMode: %04o\n"
882 "%sSloppyOptions: %s\n"
883 "%sLazyUnmount: %s\n"
884 "%sForceUnmount: %s\n"
885 "%sReadWriteOnly: %s\n"
886 "%sTimeoutSec: %s\n",
887 prefix, mount_state_to_string(m->state),
888 prefix, mount_result_to_string(m->result),
889 prefix, mount_result_to_string(m->clean_result),
890 prefix, m->where,
891 prefix, p ? strna(p->what) : "n/a",
892 prefix, p ? strna(p->fstype) : "n/a",
893 prefix, p ? strna(p->options) : "n/a",
894 prefix, yes_no(m->from_proc_self_mountinfo),
895 prefix, yes_no(m->from_fragment),
896 prefix, yes_no(mount_is_extrinsic(u)),
897 prefix, m->directory_mode,
898 prefix, yes_no(m->sloppy_options),
899 prefix, yes_no(m->lazy_unmount),
900 prefix, yes_no(m->force_unmount),
901 prefix, yes_no(m->read_write_only),
902 prefix, FORMAT_TIMESPAN(m->timeout_usec, USEC_PER_SEC));
903
904 if (pidref_is_set(&m->control_pid))
905 fprintf(f,
906 "%sControl PID: "PID_FMT"\n",
907 prefix, m->control_pid.pid);
908
909 exec_context_dump(&m->exec_context, f, prefix);
910 kill_context_dump(&m->kill_context, f, prefix);
911 cgroup_context_dump(UNIT(m), f, prefix);
912 }
913
914 static int mount_spawn(Mount *m, ExecCommand *c, PidRef *ret_pid) {
915
916 _cleanup_(exec_params_clear) ExecParameters exec_params = {
917 .flags = EXEC_APPLY_SANDBOXING|EXEC_APPLY_CHROOT|EXEC_APPLY_TTY_STDIN,
918 .stdin_fd = -EBADF,
919 .stdout_fd = -EBADF,
920 .stderr_fd = -EBADF,
921 .exec_fd = -EBADF,
922 };
923 _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL;
924 pid_t pid;
925 int r;
926
927 assert(m);
928 assert(c);
929 assert(ret_pid);
930
931 r = unit_prepare_exec(UNIT(m));
932 if (r < 0)
933 return r;
934
935 r = mount_arm_timer(m, usec_add(now(CLOCK_MONOTONIC), m->timeout_usec));
936 if (r < 0)
937 return r;
938
939 r = unit_set_exec_params(UNIT(m), &exec_params);
940 if (r < 0)
941 return r;
942
943 r = exec_spawn(UNIT(m),
944 c,
945 &m->exec_context,
946 &exec_params,
947 m->exec_runtime,
948 &m->cgroup_context,
949 &pid);
950 if (r < 0)
951 return r;
952
953 r = pidref_set_pid(&pidref, pid);
954 if (r < 0)
955 return r;
956
957 r = unit_watch_pid(UNIT(m), pidref.pid, /* exclusive= */ true);
958 if (r < 0)
959 return r;
960
961 *ret_pid = TAKE_PIDREF(pidref);
962 return 0;
963 }
964
965 static void mount_enter_dead(Mount *m, MountResult f) {
966 assert(m);
967
968 if (m->result == MOUNT_SUCCESS)
969 m->result = f;
970
971 unit_log_result(UNIT(m), m->result == MOUNT_SUCCESS, mount_result_to_string(m->result));
972 unit_warn_leftover_processes(UNIT(m), unit_log_leftover_process_stop);
973
974 mount_set_state(m, m->result != MOUNT_SUCCESS ? MOUNT_FAILED : MOUNT_DEAD);
975
976 m->exec_runtime = exec_runtime_destroy(m->exec_runtime);
977
978 unit_destroy_runtime_data(UNIT(m), &m->exec_context);
979
980 unit_unref_uid_gid(UNIT(m), true);
981
982 /* Any dependencies based on /proc/self/mountinfo are now stale. Let's re-generate dependencies from
983 * .mount unit. */
984 (void) mount_add_non_exec_dependencies(m);
985 }
986
987 static void mount_enter_mounted(Mount *m, MountResult f) {
988 assert(m);
989
990 if (m->result == MOUNT_SUCCESS)
991 m->result = f;
992
993 mount_set_state(m, MOUNT_MOUNTED);
994 }
995
996 static void mount_enter_dead_or_mounted(Mount *m, MountResult f) {
997 assert(m);
998
999 /* Enter DEAD or MOUNTED state, depending on what the kernel currently says about the mount point. We use this
1000 * whenever we executed an operation, so that our internal state reflects what the kernel says again, after all
1001 * ultimately we just mirror the kernel's internal state on this. */
1002
1003 if (m->from_proc_self_mountinfo)
1004 mount_enter_mounted(m, f);
1005 else
1006 mount_enter_dead(m, f);
1007 }
1008
1009 static int state_to_kill_operation(MountState state) {
1010 switch (state) {
1011
1012 case MOUNT_REMOUNTING_SIGTERM:
1013 return KILL_RESTART;
1014
1015 case MOUNT_UNMOUNTING_SIGTERM:
1016 return KILL_TERMINATE;
1017
1018 case MOUNT_REMOUNTING_SIGKILL:
1019 case MOUNT_UNMOUNTING_SIGKILL:
1020 return KILL_KILL;
1021
1022 default:
1023 return _KILL_OPERATION_INVALID;
1024 }
1025 }
1026
1027 static void mount_enter_signal(Mount *m, MountState state, MountResult f) {
1028 int r;
1029
1030 assert(m);
1031
1032 if (m->result == MOUNT_SUCCESS)
1033 m->result = f;
1034
1035 r = unit_kill_context(
1036 UNIT(m),
1037 &m->kill_context,
1038 state_to_kill_operation(state),
1039 /* main_pid= */ NULL,
1040 &m->control_pid,
1041 /* main_pid_alien= */ false);
1042 if (r < 0) {
1043 log_unit_warning_errno(UNIT(m), r, "Failed to kill processes: %m");
1044 goto fail;
1045 }
1046
1047 if (r > 0) {
1048 r = mount_arm_timer(m, usec_add(now(CLOCK_MONOTONIC), m->timeout_usec));
1049 if (r < 0) {
1050 log_unit_warning_errno(UNIT(m), r, "Failed to install timer: %m");
1051 goto fail;
1052 }
1053
1054 mount_set_state(m, state);
1055 } else if (state == MOUNT_REMOUNTING_SIGTERM && m->kill_context.send_sigkill)
1056 mount_enter_signal(m, MOUNT_REMOUNTING_SIGKILL, MOUNT_SUCCESS);
1057 else if (IN_SET(state, MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL))
1058 mount_enter_mounted(m, MOUNT_SUCCESS);
1059 else if (state == MOUNT_UNMOUNTING_SIGTERM && m->kill_context.send_sigkill)
1060 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGKILL, MOUNT_SUCCESS);
1061 else
1062 mount_enter_dead_or_mounted(m, MOUNT_SUCCESS);
1063
1064 return;
1065
1066 fail:
1067 mount_enter_dead_or_mounted(m, MOUNT_FAILURE_RESOURCES);
1068 }
1069
1070 static int mount_set_umount_command(Mount *m, ExecCommand *c) {
1071 int r;
1072
1073 assert(m);
1074 assert(c);
1075
1076 r = exec_command_set(c, UMOUNT_PATH, m->where, "-c", NULL);
1077 if (r < 0)
1078 return r;
1079
1080 if (m->lazy_unmount) {
1081 r = exec_command_append(c, "-l", NULL);
1082 if (r < 0)
1083 return r;
1084 }
1085
1086 if (m->force_unmount) {
1087 r = exec_command_append(c, "-f", NULL);
1088 if (r < 0)
1089 return r;
1090 }
1091
1092 return 0;
1093 }
1094
1095 static void mount_enter_unmounting(Mount *m) {
1096 int r;
1097
1098 assert(m);
1099
1100 /* Start counting our attempts */
1101 if (!IN_SET(m->state,
1102 MOUNT_UNMOUNTING,
1103 MOUNT_UNMOUNTING_SIGTERM,
1104 MOUNT_UNMOUNTING_SIGKILL))
1105 m->n_retry_umount = 0;
1106
1107 m->control_command_id = MOUNT_EXEC_UNMOUNT;
1108 m->control_command = m->exec_command + MOUNT_EXEC_UNMOUNT;
1109
1110 r = mount_set_umount_command(m, m->control_command);
1111 if (r < 0) {
1112 log_unit_warning_errno(UNIT(m), r, "Failed to prepare umount command line: %m");
1113 goto fail;
1114 }
1115
1116 mount_unwatch_control_pid(m);
1117
1118 r = mount_spawn(m, m->control_command, &m->control_pid);
1119 if (r < 0) {
1120 log_unit_warning_errno(UNIT(m), r, "Failed to spawn 'umount' task: %m");
1121 goto fail;
1122 }
1123
1124 mount_set_state(m, MOUNT_UNMOUNTING);
1125
1126 return;
1127
1128 fail:
1129 mount_enter_dead_or_mounted(m, MOUNT_FAILURE_RESOURCES);
1130 }
1131
1132 static int mount_set_mount_command(Mount *m, ExecCommand *c, const MountParameters *p) {
1133 int r;
1134
1135 assert(m);
1136 assert(c);
1137 assert(p);
1138
1139 r = exec_command_set(c, MOUNT_PATH, p->what, m->where, NULL);
1140 if (r < 0)
1141 return r;
1142
1143 if (m->sloppy_options) {
1144 r = exec_command_append(c, "-s", NULL);
1145 if (r < 0)
1146 return r;
1147 }
1148
1149 if (m->read_write_only) {
1150 r = exec_command_append(c, "-w", NULL);
1151 if (r < 0)
1152 return r;
1153 }
1154
1155 if (p->fstype) {
1156 r = exec_command_append(c, "-t", p->fstype, NULL);
1157 if (r < 0)
1158 return r;
1159 }
1160
1161 _cleanup_free_ char *opts = NULL;
1162 r = fstab_filter_options(p->options, "nofail\0" "noauto\0" "auto\0", NULL, NULL, NULL, &opts);
1163 if (r < 0)
1164 return r;
1165
1166 if (!isempty(opts)) {
1167 r = exec_command_append(c, "-o", opts, NULL);
1168 if (r < 0)
1169 return r;
1170 }
1171
1172 return 0;
1173 }
1174
1175 static void mount_enter_mounting(Mount *m) {
1176 int r;
1177 MountParameters *p;
1178 bool source_is_dir = true;
1179
1180 assert(m);
1181
1182 r = unit_fail_if_noncanonical(UNIT(m), m->where);
1183 if (r < 0)
1184 goto fail;
1185
1186 p = get_mount_parameters_fragment(m);
1187 if (p && mount_is_bind(p)) {
1188 r = is_dir(p->what, /* follow = */ true);
1189 if (r < 0 && r != -ENOENT)
1190 log_unit_info_errno(UNIT(m), r, "Failed to determine type of bind mount source '%s', ignoring: %m", p->what);
1191 else if (r == 0)
1192 source_is_dir = false;
1193 }
1194
1195 if (source_is_dir)
1196 (void) mkdir_p_label(m->where, m->directory_mode);
1197 else
1198 (void) touch_file(m->where, /* parents = */ true, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID);
1199
1200 if (source_is_dir)
1201 unit_warn_if_dir_nonempty(UNIT(m), m->where);
1202 unit_warn_leftover_processes(UNIT(m), unit_log_leftover_process_start);
1203
1204 m->control_command_id = MOUNT_EXEC_MOUNT;
1205 m->control_command = m->exec_command + MOUNT_EXEC_MOUNT;
1206
1207 /* Create the source directory for bind-mounts if needed */
1208 if (p && mount_is_bind(p)) {
1209 r = mkdir_p_label(p->what, m->directory_mode);
1210 /* mkdir_p_label() can return -EEXIST if the target path exists and is not a directory - which is
1211 * totally OK, in case the user wants us to overmount a non-directory inode. Also -EROFS can be
1212 * returned on read-only filesystem. Moreover, -EACCES (and also maybe -EPERM?) may be returned
1213 * when the path is on NFS. See issue #24120. All such errors will be logged in the debug level. */
1214 if (r < 0 && r != -EEXIST)
1215 log_unit_full_errno(UNIT(m),
1216 (r == -EROFS || ERRNO_IS_PRIVILEGE(r)) ? LOG_DEBUG : LOG_WARNING,
1217 r, "Failed to make bind mount source '%s', ignoring: %m", p->what);
1218 }
1219
1220 if (p) {
1221 r = mount_set_mount_command(m, m->control_command, p);
1222 if (r < 0) {
1223 log_unit_warning_errno(UNIT(m), r, "Failed to prepare mount command line: %m");
1224 goto fail;
1225 }
1226 } else {
1227 r = log_unit_warning_errno(UNIT(m), SYNTHETIC_ERRNO(ENOENT), "No mount parameters to operate on.");
1228 goto fail;
1229 }
1230
1231 mount_unwatch_control_pid(m);
1232
1233 r = mount_spawn(m, m->control_command, &m->control_pid);
1234 if (r < 0) {
1235 log_unit_warning_errno(UNIT(m), r, "Failed to spawn 'mount' task: %m");
1236 goto fail;
1237 }
1238
1239 mount_set_state(m, MOUNT_MOUNTING);
1240 return;
1241
1242 fail:
1243 mount_enter_dead_or_mounted(m, MOUNT_FAILURE_RESOURCES);
1244 }
1245
1246 static void mount_set_reload_result(Mount *m, MountResult result) {
1247 assert(m);
1248
1249 /* Only store the first error we encounter */
1250 if (m->reload_result != MOUNT_SUCCESS)
1251 return;
1252
1253 m->reload_result = result;
1254 }
1255
1256 static void mount_enter_remounting(Mount *m) {
1257 int r;
1258 MountParameters *p;
1259
1260 assert(m);
1261
1262 /* Reset reload result when we are about to start a new remount operation */
1263 m->reload_result = MOUNT_SUCCESS;
1264
1265 m->control_command_id = MOUNT_EXEC_REMOUNT;
1266 m->control_command = m->exec_command + MOUNT_EXEC_REMOUNT;
1267
1268 p = get_mount_parameters_fragment(m);
1269 if (p) {
1270 const char *o;
1271
1272 if (p->options)
1273 o = strjoina("remount,", p->options);
1274 else
1275 o = "remount";
1276
1277 r = exec_command_set(m->control_command, MOUNT_PATH,
1278 p->what, m->where,
1279 "-o", o, NULL);
1280 if (r >= 0 && m->sloppy_options)
1281 r = exec_command_append(m->control_command, "-s", NULL);
1282 if (r >= 0 && m->read_write_only)
1283 r = exec_command_append(m->control_command, "-w", NULL);
1284 if (r >= 0 && p->fstype)
1285 r = exec_command_append(m->control_command, "-t", p->fstype, NULL);
1286 if (r < 0) {
1287 log_unit_warning_errno(UNIT(m), r, "Failed to prepare remount command line: %m");
1288 goto fail;
1289 }
1290
1291 } else {
1292 r = log_unit_warning_errno(UNIT(m), SYNTHETIC_ERRNO(ENOENT), "No mount parameters to operate on.");
1293 goto fail;
1294 }
1295
1296 mount_unwatch_control_pid(m);
1297
1298 r = mount_spawn(m, m->control_command, &m->control_pid);
1299 if (r < 0) {
1300 log_unit_warning_errno(UNIT(m), r, "Failed to spawn 'remount' task: %m");
1301 goto fail;
1302 }
1303
1304 mount_set_state(m, MOUNT_REMOUNTING);
1305 return;
1306
1307 fail:
1308 mount_set_reload_result(m, MOUNT_FAILURE_RESOURCES);
1309 mount_enter_dead_or_mounted(m, MOUNT_SUCCESS);
1310 }
1311
1312 static void mount_cycle_clear(Mount *m) {
1313 assert(m);
1314
1315 /* Clear all state we shall forget for this new cycle */
1316
1317 m->result = MOUNT_SUCCESS;
1318 m->reload_result = MOUNT_SUCCESS;
1319 exec_command_reset_status_array(m->exec_command, _MOUNT_EXEC_COMMAND_MAX);
1320 UNIT(m)->reset_accounting = true;
1321 }
1322
1323 static int mount_start(Unit *u) {
1324 Mount *m = MOUNT(u);
1325 int r;
1326
1327 assert(m);
1328
1329 /* We cannot fulfill this request right now, try again later
1330 * please! */
1331 if (IN_SET(m->state,
1332 MOUNT_UNMOUNTING,
1333 MOUNT_UNMOUNTING_SIGTERM,
1334 MOUNT_UNMOUNTING_SIGKILL,
1335 MOUNT_CLEANING))
1336 return -EAGAIN;
1337
1338 /* Already on it! */
1339 if (IN_SET(m->state, MOUNT_MOUNTING, MOUNT_MOUNTING_DONE))
1340 return 0;
1341
1342 assert(IN_SET(m->state, MOUNT_DEAD, MOUNT_FAILED));
1343
1344 r = unit_acquire_invocation_id(u);
1345 if (r < 0)
1346 return r;
1347
1348 mount_cycle_clear(m);
1349 mount_enter_mounting(m);
1350
1351 return 1;
1352 }
1353
1354 static int mount_stop(Unit *u) {
1355 Mount *m = MOUNT(u);
1356
1357 assert(m);
1358
1359 /* When we directly call umount() for a path, then the state of the corresponding mount unit may be
1360 * outdated. Let's re-read mountinfo now and update the state. */
1361 if (m->invalidated_state)
1362 (void) mount_process_proc_self_mountinfo(u->manager);
1363
1364 switch (m->state) {
1365
1366 case MOUNT_UNMOUNTING:
1367 case MOUNT_UNMOUNTING_SIGKILL:
1368 case MOUNT_UNMOUNTING_SIGTERM:
1369 /* Already on it */
1370 return 0;
1371
1372 case MOUNT_MOUNTING:
1373 case MOUNT_MOUNTING_DONE:
1374 case MOUNT_REMOUNTING:
1375 /* If we are still waiting for /bin/mount, we go directly into kill mode. */
1376 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGTERM, MOUNT_SUCCESS);
1377 return 0;
1378
1379 case MOUNT_REMOUNTING_SIGTERM:
1380 /* If we are already waiting for a hung remount, convert this to the matching unmounting state */
1381 mount_set_state(m, MOUNT_UNMOUNTING_SIGTERM);
1382 return 0;
1383
1384 case MOUNT_REMOUNTING_SIGKILL:
1385 /* as above */
1386 mount_set_state(m, MOUNT_UNMOUNTING_SIGKILL);
1387 return 0;
1388
1389 case MOUNT_MOUNTED:
1390 mount_enter_unmounting(m);
1391 return 1;
1392
1393 case MOUNT_CLEANING:
1394 /* If we are currently cleaning, then abort it, brutally. */
1395 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGKILL, MOUNT_SUCCESS);
1396 return 0;
1397
1398 case MOUNT_DEAD:
1399 case MOUNT_FAILED:
1400 /* The mount has just been unmounted by somebody else. */
1401 return 0;
1402
1403 default:
1404 assert_not_reached();
1405 }
1406 }
1407
1408 static int mount_reload(Unit *u) {
1409 Mount *m = MOUNT(u);
1410
1411 assert(m);
1412 assert(m->state == MOUNT_MOUNTED);
1413
1414 mount_enter_remounting(m);
1415
1416 return 1;
1417 }
1418
1419 static int mount_serialize(Unit *u, FILE *f, FDSet *fds) {
1420 Mount *m = MOUNT(u);
1421
1422 assert(m);
1423 assert(f);
1424 assert(fds);
1425
1426 (void) serialize_item(f, "state", mount_state_to_string(m->state));
1427 (void) serialize_item(f, "result", mount_result_to_string(m->result));
1428 (void) serialize_item(f, "reload-result", mount_result_to_string(m->reload_result));
1429 (void) serialize_item_format(f, "n-retry-umount", "%u", m->n_retry_umount);
1430
1431 if (pidref_is_set(&m->control_pid))
1432 (void) serialize_item_format(f, "control-pid", PID_FMT, m->control_pid.pid);
1433
1434 if (m->control_command_id >= 0)
1435 (void) serialize_item(f, "control-command", mount_exec_command_to_string(m->control_command_id));
1436
1437 return 0;
1438 }
1439
1440 static int mount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
1441 Mount *m = MOUNT(u);
1442 int r;
1443
1444 assert(m);
1445 assert(u);
1446 assert(key);
1447 assert(value);
1448 assert(fds);
1449
1450 if (streq(key, "state")) {
1451 MountState state;
1452
1453 state = mount_state_from_string(value);
1454 if (state < 0)
1455 log_unit_debug_errno(u, state, "Failed to parse state value: %s", value);
1456 else
1457 m->deserialized_state = state;
1458
1459 } else if (streq(key, "result")) {
1460 MountResult f;
1461
1462 f = mount_result_from_string(value);
1463 if (f < 0)
1464 log_unit_debug_errno(u, f, "Failed to parse result value: %s", value);
1465 else if (f != MOUNT_SUCCESS)
1466 m->result = f;
1467
1468 } else if (streq(key, "reload-result")) {
1469 MountResult f;
1470
1471 f = mount_result_from_string(value);
1472 if (f < 0)
1473 log_unit_debug_errno(u, f, "Failed to parse reload result value: %s", value);
1474 else if (f != MOUNT_SUCCESS)
1475 m->reload_result = f;
1476
1477 } else if (streq(key, "n-retry-umount")) {
1478
1479 r = safe_atou(value, &m->n_retry_umount);
1480 if (r < 0)
1481 log_unit_debug_errno(u, r, "Failed to parse n-retry-umount value: %s", value);
1482
1483 } else if (streq(key, "control-pid")) {
1484
1485 pidref_done(&m->control_pid);
1486 r = pidref_set_pidstr(&m->control_pid, value);
1487 if (r < 0)
1488 log_debug_errno(r, "Failed to set control PID to '%s': %m", value);
1489
1490 } else if (streq(key, "control-command")) {
1491 MountExecCommand id;
1492
1493 id = mount_exec_command_from_string(value);
1494 if (id < 0)
1495 log_unit_debug_errno(u, id, "Failed to parse exec-command value: %s", value);
1496 else {
1497 m->control_command_id = id;
1498 m->control_command = m->exec_command + id;
1499 }
1500 } else
1501 log_unit_debug(u, "Unknown serialization key: %s", key);
1502
1503 return 0;
1504 }
1505
1506 static UnitActiveState mount_active_state(Unit *u) {
1507 assert(u);
1508
1509 return state_translation_table[MOUNT(u)->state];
1510 }
1511
1512 static const char *mount_sub_state_to_string(Unit *u) {
1513 assert(u);
1514
1515 return mount_state_to_string(MOUNT(u)->state);
1516 }
1517
1518 static bool mount_may_gc(Unit *u) {
1519 Mount *m = MOUNT(u);
1520
1521 assert(m);
1522
1523 if (m->from_proc_self_mountinfo)
1524 return false;
1525
1526 return true;
1527 }
1528
1529 static void mount_sigchld_event(Unit *u, pid_t pid, int code, int status) {
1530 Mount *m = MOUNT(u);
1531 MountResult f;
1532
1533 assert(m);
1534 assert(pid >= 0);
1535
1536 if (pid != m->control_pid.pid)
1537 return;
1538
1539 /* So here's the thing, we really want to know before /usr/bin/mount or /usr/bin/umount exit whether
1540 * they established/remove a mount. This is important when mounting, but even more so when unmounting
1541 * since we need to deal with nested mounts and otherwise cannot safely determine whether to repeat
1542 * the unmounts. In theory, the kernel fires /proc/self/mountinfo changes off before returning from
1543 * the mount() or umount() syscalls, and thus we should see the changes to the proc file before we
1544 * process the waitid() for the /usr/bin/(u)mount processes. However, this is unfortunately racy: we
1545 * have to waitid() for processes using P_ALL (since we need to reap unexpected children that got
1546 * reparented to PID 1), but when using P_ALL we might end up reaping processes that terminated just
1547 * instants ago, i.e. already after our last event loop iteration (i.e. after the last point we might
1548 * have noticed /proc/self/mountinfo events via epoll). This means event loop priorities for
1549 * processing SIGCHLD vs. /proc/self/mountinfo IO events are not as relevant as we want. To fix that
1550 * race, let's explicitly scan /proc/self/mountinfo before we start processing /usr/bin/(u)mount
1551 * dying. It's ugly, but it makes our ordering systematic again, and makes sure we always see
1552 * /proc/self/mountinfo changes before our mount/umount exits. */
1553 (void) mount_process_proc_self_mountinfo(u->manager);
1554
1555 pidref_done(&m->control_pid);
1556
1557 if (is_clean_exit(code, status, EXIT_CLEAN_COMMAND, NULL))
1558 f = MOUNT_SUCCESS;
1559 else if (code == CLD_EXITED)
1560 f = MOUNT_FAILURE_EXIT_CODE;
1561 else if (code == CLD_KILLED)
1562 f = MOUNT_FAILURE_SIGNAL;
1563 else if (code == CLD_DUMPED)
1564 f = MOUNT_FAILURE_CORE_DUMP;
1565 else
1566 assert_not_reached();
1567
1568 if (IN_SET(m->state, MOUNT_REMOUNTING, MOUNT_REMOUNTING_SIGKILL, MOUNT_REMOUNTING_SIGTERM))
1569 mount_set_reload_result(m, f);
1570 else if (m->result == MOUNT_SUCCESS)
1571 m->result = f;
1572
1573 if (m->control_command) {
1574 exec_status_exit(&m->control_command->exec_status, &m->exec_context, pid, code, status);
1575
1576 m->control_command = NULL;
1577 m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
1578 }
1579
1580 unit_log_process_exit(
1581 u,
1582 "Mount process",
1583 mount_exec_command_to_string(m->control_command_id),
1584 f == MOUNT_SUCCESS,
1585 code, status);
1586
1587 /* Note that due to the io event priority logic, we can be sure the new mountinfo is loaded
1588 * before we process the SIGCHLD for the mount command. */
1589
1590 switch (m->state) {
1591
1592 case MOUNT_MOUNTING:
1593 /* Our mount point has not appeared in mountinfo. Something went wrong. */
1594
1595 if (f == MOUNT_SUCCESS) {
1596 /* Either /bin/mount has an unexpected definition of success,
1597 * or someone raced us and we lost. */
1598 log_unit_warning(UNIT(m), "Mount process finished, but there is no mount.");
1599 f = MOUNT_FAILURE_PROTOCOL;
1600 }
1601 mount_enter_dead(m, f);
1602 break;
1603
1604 case MOUNT_MOUNTING_DONE:
1605 mount_enter_mounted(m, f);
1606 break;
1607
1608 case MOUNT_REMOUNTING:
1609 case MOUNT_REMOUNTING_SIGTERM:
1610 case MOUNT_REMOUNTING_SIGKILL:
1611 mount_enter_dead_or_mounted(m, MOUNT_SUCCESS);
1612 break;
1613
1614 case MOUNT_UNMOUNTING:
1615
1616 if (f == MOUNT_SUCCESS && m->from_proc_self_mountinfo) {
1617
1618 /* Still a mount point? If so, let's try again. Most likely there were multiple mount points
1619 * stacked on top of each other. We might exceed the timeout specified by the user overall,
1620 * but we will stop as soon as any one umount times out. */
1621
1622 if (m->n_retry_umount < RETRY_UMOUNT_MAX) {
1623 log_unit_debug(u, "Mount still present, trying again.");
1624 m->n_retry_umount++;
1625 mount_enter_unmounting(m);
1626 } else {
1627 log_unit_warning(u, "Mount still present after %u attempts to unmount, giving up.", m->n_retry_umount);
1628 mount_enter_mounted(m, f);
1629 }
1630 } else
1631 mount_enter_dead_or_mounted(m, f);
1632
1633 break;
1634
1635 case MOUNT_UNMOUNTING_SIGKILL:
1636 case MOUNT_UNMOUNTING_SIGTERM:
1637 mount_enter_dead_or_mounted(m, f);
1638 break;
1639
1640 case MOUNT_CLEANING:
1641 if (m->clean_result == MOUNT_SUCCESS)
1642 m->clean_result = f;
1643
1644 mount_enter_dead(m, MOUNT_SUCCESS);
1645 break;
1646
1647 default:
1648 assert_not_reached();
1649 }
1650
1651 /* Notify clients about changed exit status */
1652 unit_add_to_dbus_queue(u);
1653 }
1654
1655 static int mount_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
1656 Mount *m = MOUNT(userdata);
1657
1658 assert(m);
1659 assert(m->timer_event_source == source);
1660
1661 switch (m->state) {
1662
1663 case MOUNT_MOUNTING:
1664 case MOUNT_MOUNTING_DONE:
1665 log_unit_warning(UNIT(m), "Mounting timed out. Terminating.");
1666 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGTERM, MOUNT_FAILURE_TIMEOUT);
1667 break;
1668
1669 case MOUNT_REMOUNTING:
1670 log_unit_warning(UNIT(m), "Remounting timed out. Terminating remount process.");
1671 mount_set_reload_result(m, MOUNT_FAILURE_TIMEOUT);
1672 mount_enter_signal(m, MOUNT_REMOUNTING_SIGTERM, MOUNT_SUCCESS);
1673 break;
1674
1675 case MOUNT_REMOUNTING_SIGTERM:
1676 mount_set_reload_result(m, MOUNT_FAILURE_TIMEOUT);
1677
1678 if (m->kill_context.send_sigkill) {
1679 log_unit_warning(UNIT(m), "Remounting timed out. Killing.");
1680 mount_enter_signal(m, MOUNT_REMOUNTING_SIGKILL, MOUNT_SUCCESS);
1681 } else {
1682 log_unit_warning(UNIT(m), "Remounting timed out. Skipping SIGKILL. Ignoring.");
1683 mount_enter_dead_or_mounted(m, MOUNT_SUCCESS);
1684 }
1685 break;
1686
1687 case MOUNT_REMOUNTING_SIGKILL:
1688 mount_set_reload_result(m, MOUNT_FAILURE_TIMEOUT);
1689
1690 log_unit_warning(UNIT(m), "Mount process still around after SIGKILL. Ignoring.");
1691 mount_enter_dead_or_mounted(m, MOUNT_SUCCESS);
1692 break;
1693
1694 case MOUNT_UNMOUNTING:
1695 log_unit_warning(UNIT(m), "Unmounting timed out. Terminating.");
1696 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGTERM, MOUNT_FAILURE_TIMEOUT);
1697 break;
1698
1699 case MOUNT_UNMOUNTING_SIGTERM:
1700 if (m->kill_context.send_sigkill) {
1701 log_unit_warning(UNIT(m), "Mount process timed out. Killing.");
1702 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGKILL, MOUNT_FAILURE_TIMEOUT);
1703 } else {
1704 log_unit_warning(UNIT(m), "Mount process timed out. Skipping SIGKILL. Ignoring.");
1705 mount_enter_dead_or_mounted(m, MOUNT_FAILURE_TIMEOUT);
1706 }
1707 break;
1708
1709 case MOUNT_UNMOUNTING_SIGKILL:
1710 log_unit_warning(UNIT(m), "Mount process still around after SIGKILL. Ignoring.");
1711 mount_enter_dead_or_mounted(m, MOUNT_FAILURE_TIMEOUT);
1712 break;
1713
1714 case MOUNT_CLEANING:
1715 log_unit_warning(UNIT(m), "Cleaning timed out. killing.");
1716
1717 if (m->clean_result == MOUNT_SUCCESS)
1718 m->clean_result = MOUNT_FAILURE_TIMEOUT;
1719
1720 mount_enter_signal(m, MOUNT_UNMOUNTING_SIGKILL, 0);
1721 break;
1722
1723 default:
1724 assert_not_reached();
1725 }
1726
1727 return 0;
1728 }
1729
1730 static int mount_setup_new_unit(
1731 Manager *m,
1732 const char *name,
1733 const char *what,
1734 const char *where,
1735 const char *options,
1736 const char *fstype,
1737 MountProcFlags *ret_flags,
1738 Unit **ret) {
1739
1740 _cleanup_(unit_freep) Unit *u = NULL;
1741 int r;
1742
1743 assert(m);
1744 assert(name);
1745 assert(ret_flags);
1746 assert(ret);
1747
1748 r = unit_new_for_name(m, sizeof(Mount), name, &u);
1749 if (r < 0)
1750 return r;
1751
1752 r = free_and_strdup(&u->source_path, "/proc/self/mountinfo");
1753 if (r < 0)
1754 return r;
1755
1756 r = free_and_strdup(&MOUNT(u)->where, where);
1757 if (r < 0)
1758 return r;
1759
1760 r = update_parameters_proc_self_mountinfo(MOUNT(u), what, options, fstype);
1761 if (r < 0)
1762 return r;
1763
1764 /* This unit was generated because /proc/self/mountinfo reported it. Remember this, so that by the
1765 * time we load the unit file for it (and thus add in extra deps right after) we know what source to
1766 * attributes the deps to. */
1767 MOUNT(u)->from_proc_self_mountinfo = true;
1768
1769 r = mount_add_non_exec_dependencies(MOUNT(u));
1770 if (r < 0)
1771 return r;
1772
1773 /* We have only allocated the stub now, let's enqueue this unit for loading now, so that everything
1774 * else is loaded in now. */
1775 unit_add_to_load_queue(u);
1776
1777 *ret_flags = MOUNT_PROC_IS_MOUNTED | MOUNT_PROC_JUST_MOUNTED | MOUNT_PROC_JUST_CHANGED;
1778 *ret = TAKE_PTR(u);
1779 return 0;
1780 }
1781
1782 static int mount_setup_existing_unit(
1783 Unit *u,
1784 const char *what,
1785 const char *where,
1786 const char *options,
1787 const char *fstype,
1788 MountProcFlags *ret_flags) {
1789
1790 int r;
1791
1792 assert(u);
1793 assert(ret_flags);
1794
1795 if (!MOUNT(u)->where) {
1796 MOUNT(u)->where = strdup(where);
1797 if (!MOUNT(u)->where)
1798 return -ENOMEM;
1799 }
1800
1801 /* In case we have multiple mounts established on the same mount point, let's merge flags set already
1802 * for the current unit. Note that the flags field is reset on each iteration of reading
1803 * /proc/self/mountinfo, hence we know for sure anything already set here is from the current
1804 * iteration and thus worthy of taking into account. */
1805 MountProcFlags flags =
1806 MOUNT(u)->proc_flags | MOUNT_PROC_IS_MOUNTED;
1807
1808 r = update_parameters_proc_self_mountinfo(MOUNT(u), what, options, fstype);
1809 if (r < 0)
1810 return r;
1811 if (r > 0)
1812 flags |= MOUNT_PROC_JUST_CHANGED;
1813
1814 /* There are two conditions when we consider a mount point just mounted: when we haven't seen it in
1815 * /proc/self/mountinfo before or when MOUNT_MOUNTING is our current state. Why bother with the
1816 * latter? Shouldn't that be covered by the former? No, during reload it is not because we might then
1817 * encounter a new /proc/self/mountinfo in combination with an old mount unit state (since it stems
1818 * from the serialized state), and need to catch up. Since we know that the MOUNT_MOUNTING state is
1819 * reached when we wait for the mount to appear we hence can assume that if we are in it, we are
1820 * actually seeing it established for the first time. */
1821 if (!MOUNT(u)->from_proc_self_mountinfo || MOUNT(u)->state == MOUNT_MOUNTING)
1822 flags |= MOUNT_PROC_JUST_MOUNTED;
1823
1824 MOUNT(u)->from_proc_self_mountinfo = true;
1825
1826 if (IN_SET(u->load_state, UNIT_NOT_FOUND, UNIT_BAD_SETTING, UNIT_ERROR)) {
1827 /* The unit was previously not found or otherwise not loaded. Now that the unit shows up in
1828 * /proc/self/mountinfo we should reconsider it this, hence set it to UNIT_LOADED. */
1829 u->load_state = UNIT_LOADED;
1830 u->load_error = 0;
1831
1832 flags |= MOUNT_PROC_JUST_CHANGED;
1833 }
1834
1835 if (FLAGS_SET(flags, MOUNT_PROC_JUST_CHANGED)) {
1836 /* If things changed, then make sure that all deps are regenerated. Let's
1837 * first remove all automatic deps, and then add in the new ones. */
1838 r = mount_add_non_exec_dependencies(MOUNT(u));
1839 if (r < 0)
1840 return r;
1841 }
1842
1843 *ret_flags = flags;
1844 return 0;
1845 }
1846
1847 static int mount_setup_unit(
1848 Manager *m,
1849 const char *what,
1850 const char *where,
1851 const char *options,
1852 const char *fstype,
1853 bool set_flags) {
1854
1855 _cleanup_free_ char *e = NULL;
1856 MountProcFlags flags;
1857 Unit *u;
1858 int r;
1859
1860 assert(m);
1861 assert(what);
1862 assert(where);
1863 assert(options);
1864 assert(fstype);
1865
1866 /* Ignore API mount points. They should never be referenced in
1867 * dependencies ever. */
1868 if (mount_point_is_api(where) || mount_point_ignore(where))
1869 return 0;
1870
1871 if (streq(fstype, "autofs"))
1872 return 0;
1873
1874 /* probably some kind of swap, ignore */
1875 if (!is_path(where))
1876 return 0;
1877
1878 r = unit_name_from_path(where, ".mount", &e);
1879 if (r < 0)
1880 return log_struct_errno(
1881 LOG_WARNING, r,
1882 "MESSAGE_ID=" SD_MESSAGE_MOUNT_POINT_PATH_NOT_SUITABLE_STR,
1883 "MOUNT_POINT=%s", where,
1884 LOG_MESSAGE("Failed to generate valid unit name from mount point path '%s', ignoring mount point: %m",
1885 where));
1886
1887 u = manager_get_unit(m, e);
1888 if (u)
1889 r = mount_setup_existing_unit(u, what, where, options, fstype, &flags);
1890 else
1891 /* First time we see this mount point meaning that it's not been initiated by a mount unit
1892 * but rather by the sysadmin having called mount(8) directly. */
1893 r = mount_setup_new_unit(m, e, what, where, options, fstype, &flags, &u);
1894 if (r < 0)
1895 return log_warning_errno(r, "Failed to set up mount unit for '%s': %m", where);
1896
1897 /* If the mount changed properties or state, let's notify our clients */
1898 if (flags & (MOUNT_PROC_JUST_CHANGED|MOUNT_PROC_JUST_MOUNTED))
1899 unit_add_to_dbus_queue(u);
1900
1901 if (set_flags)
1902 MOUNT(u)->proc_flags = flags;
1903
1904 return 0;
1905 }
1906
1907 static int mount_load_proc_self_mountinfo(Manager *m, bool set_flags) {
1908 _cleanup_(mnt_free_tablep) struct libmnt_table *table = NULL;
1909 _cleanup_(mnt_free_iterp) struct libmnt_iter *iter = NULL;
1910 int r;
1911
1912 assert(m);
1913
1914 r = libmount_parse(NULL, NULL, &table, &iter);
1915 if (r < 0)
1916 return log_error_errno(r, "Failed to parse /proc/self/mountinfo: %m");
1917
1918 for (;;) {
1919 struct libmnt_fs *fs;
1920 const char *device, *path, *options, *fstype;
1921
1922 r = mnt_table_next_fs(table, iter, &fs);
1923 if (r == 1)
1924 break;
1925 if (r < 0)
1926 return log_error_errno(r, "Failed to get next entry from /proc/self/mountinfo: %m");
1927
1928 device = mnt_fs_get_source(fs);
1929 path = mnt_fs_get_target(fs);
1930 options = mnt_fs_get_options(fs);
1931 fstype = mnt_fs_get_fstype(fs);
1932
1933 if (!device || !path)
1934 continue;
1935
1936 device_found_node(m, device, DEVICE_FOUND_MOUNT, DEVICE_FOUND_MOUNT);
1937
1938 (void) mount_setup_unit(m, device, path, options, fstype, set_flags);
1939 }
1940
1941 return 0;
1942 }
1943
1944 static void mount_shutdown(Manager *m) {
1945 assert(m);
1946
1947 m->mount_event_source = sd_event_source_disable_unref(m->mount_event_source);
1948
1949 mnt_unref_monitor(m->mount_monitor);
1950 m->mount_monitor = NULL;
1951 }
1952
1953 static int mount_get_timeout(Unit *u, usec_t *timeout) {
1954 Mount *m = MOUNT(u);
1955 usec_t t;
1956 int r;
1957
1958 assert(m);
1959 assert(u);
1960
1961 if (!m->timer_event_source)
1962 return 0;
1963
1964 r = sd_event_source_get_time(m->timer_event_source, &t);
1965 if (r < 0)
1966 return r;
1967 if (t == USEC_INFINITY)
1968 return 0;
1969
1970 *timeout = t;
1971 return 1;
1972 }
1973
1974 static void mount_enumerate_perpetual(Manager *m) {
1975 Unit *u;
1976 int r;
1977
1978 assert(m);
1979
1980 /* Whatever happens, we know for sure that the root directory is around, and cannot go away. Let's
1981 * unconditionally synthesize it here and mark it as perpetual. */
1982
1983 u = manager_get_unit(m, SPECIAL_ROOT_MOUNT);
1984 if (!u) {
1985 r = unit_new_for_name(m, sizeof(Mount), SPECIAL_ROOT_MOUNT, &u);
1986 if (r < 0) {
1987 log_error_errno(r, "Failed to allocate the special " SPECIAL_ROOT_MOUNT " unit: %m");
1988 return;
1989 }
1990 }
1991
1992 u->perpetual = true;
1993 MOUNT(u)->deserialized_state = MOUNT_MOUNTED;
1994
1995 unit_add_to_load_queue(u);
1996 unit_add_to_dbus_queue(u);
1997 }
1998
1999 static bool mount_is_mounted(Mount *m) {
2000 assert(m);
2001
2002 return UNIT(m)->perpetual || FLAGS_SET(m->proc_flags, MOUNT_PROC_IS_MOUNTED);
2003 }
2004
2005 static int mount_on_ratelimit_expire(sd_event_source *s, void *userdata) {
2006 Manager *m = ASSERT_PTR(userdata);
2007 Job *j;
2008
2009 /* Let's enqueue all start jobs that were previously skipped because of active ratelimit. */
2010 HASHMAP_FOREACH(j, m->jobs) {
2011 if (j->unit->type != UNIT_MOUNT)
2012 continue;
2013
2014 job_add_to_run_queue(j);
2015 }
2016
2017 /* By entering ratelimited state we made all mount start jobs not runnable, now rate limit is over so
2018 * let's make sure we dispatch them in the next iteration. */
2019 manager_trigger_run_queue(m);
2020
2021 return 0;
2022 }
2023
2024 static void mount_enumerate(Manager *m) {
2025 int r;
2026
2027 assert(m);
2028
2029 mnt_init_debug(0);
2030
2031 if (!m->mount_monitor) {
2032 unsigned mount_rate_limit_burst = 5;
2033 int fd;
2034
2035 m->mount_monitor = mnt_new_monitor();
2036 if (!m->mount_monitor) {
2037 log_oom();
2038 goto fail;
2039 }
2040
2041 r = mnt_monitor_enable_kernel(m->mount_monitor, 1);
2042 if (r < 0) {
2043 log_error_errno(r, "Failed to enable watching of kernel mount events: %m");
2044 goto fail;
2045 }
2046
2047 r = mnt_monitor_enable_userspace(m->mount_monitor, 1, NULL);
2048 if (r < 0) {
2049 log_error_errno(r, "Failed to enable watching of userspace mount events: %m");
2050 goto fail;
2051 }
2052
2053 /* mnt_unref_monitor() will close the fd */
2054 fd = r = mnt_monitor_get_fd(m->mount_monitor);
2055 if (r < 0) {
2056 log_error_errno(r, "Failed to acquire watch file descriptor: %m");
2057 goto fail;
2058 }
2059
2060 r = sd_event_add_io(m->event, &m->mount_event_source, fd, EPOLLIN, mount_dispatch_io, m);
2061 if (r < 0) {
2062 log_error_errno(r, "Failed to watch mount file descriptor: %m");
2063 goto fail;
2064 }
2065
2066 r = sd_event_source_set_priority(m->mount_event_source, SD_EVENT_PRIORITY_NORMAL-10);
2067 if (r < 0) {
2068 log_error_errno(r, "Failed to adjust mount watch priority: %m");
2069 goto fail;
2070 }
2071
2072 /* Let users override the default (5 in 1s), as it stalls the boot sequence on busy systems. */
2073 const char *e = secure_getenv("SYSTEMD_DEFAULT_MOUNT_RATE_LIMIT_BURST");
2074 if (e) {
2075 r = safe_atou(e, &mount_rate_limit_burst);
2076 if (r < 0)
2077 log_debug("Invalid value in $SYSTEMD_DEFAULT_MOUNT_RATE_LIMIT_BURST, ignoring: %s", e);
2078 }
2079
2080 r = sd_event_source_set_ratelimit(m->mount_event_source, 1 * USEC_PER_SEC, mount_rate_limit_burst);
2081 if (r < 0) {
2082 log_error_errno(r, "Failed to enable rate limit for mount events: %m");
2083 goto fail;
2084 }
2085
2086 r = sd_event_source_set_ratelimit_expire_callback(m->mount_event_source, mount_on_ratelimit_expire);
2087 if (r < 0) {
2088 log_error_errno(r, "Failed to enable rate limit for mount events: %m");
2089 goto fail;
2090 }
2091
2092 (void) sd_event_source_set_description(m->mount_event_source, "mount-monitor-dispatch");
2093 }
2094
2095 r = mount_load_proc_self_mountinfo(m, false);
2096 if (r < 0)
2097 goto fail;
2098
2099 return;
2100
2101 fail:
2102 mount_shutdown(m);
2103 }
2104
2105 static int drain_libmount(Manager *m) {
2106 bool rescan = false;
2107 int r;
2108
2109 assert(m);
2110
2111 /* Drain all events and verify that the event is valid.
2112 *
2113 * Note that libmount also monitors /run/mount mkdir if the directory does not exist yet. The mkdir
2114 * may generate event which is irrelevant for us.
2115 *
2116 * error: r < 0; valid: r == 0, false positive: r == 1 */
2117 do {
2118 r = mnt_monitor_next_change(m->mount_monitor, NULL, NULL);
2119 if (r < 0)
2120 return log_error_errno(r, "Failed to drain libmount events: %m");
2121 if (r == 0)
2122 rescan = true;
2123 } while (r == 0);
2124
2125 return rescan;
2126 }
2127
2128 static int mount_process_proc_self_mountinfo(Manager *m) {
2129 _cleanup_set_free_ Set *around = NULL, *gone = NULL;
2130 const char *what;
2131 int r;
2132
2133 assert(m);
2134
2135 r = drain_libmount(m);
2136 if (r <= 0)
2137 return r;
2138
2139 r = mount_load_proc_self_mountinfo(m, true);
2140 if (r < 0) {
2141 /* Reset flags, just in case, for later calls */
2142 LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_MOUNT])
2143 MOUNT(u)->proc_flags = 0;
2144
2145 return 0;
2146 }
2147
2148 manager_dispatch_load_queue(m);
2149
2150 LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_MOUNT]) {
2151 Mount *mount = MOUNT(u);
2152
2153 mount->invalidated_state = false;
2154
2155 if (!mount_is_mounted(mount)) {
2156
2157 /* A mount point is not around right now. It might be gone, or might never have
2158 * existed. */
2159
2160 if (mount->from_proc_self_mountinfo &&
2161 mount->parameters_proc_self_mountinfo.what)
2162 /* Remember that this device might just have disappeared */
2163 if (set_put_strdup_full(&gone, &path_hash_ops_free, mount->parameters_proc_self_mountinfo.what) < 0)
2164 log_oom(); /* we don't care too much about OOM here... */
2165
2166 mount->from_proc_self_mountinfo = false;
2167 assert_se(update_parameters_proc_self_mountinfo(mount, NULL, NULL, NULL) >= 0);
2168
2169 switch (mount->state) {
2170
2171 case MOUNT_MOUNTED:
2172 /* This has just been unmounted by somebody else, follow the state change. */
2173 mount_enter_dead(mount, MOUNT_SUCCESS);
2174 break;
2175
2176 case MOUNT_MOUNTING_DONE:
2177 /* The mount command may add the corresponding proc mountinfo entry and
2178 * then remove it because of an internal error. E.g., fuse.sshfs seems
2179 * to do that when the connection fails. See #17617. To handle such the
2180 * case, let's once set the state back to mounting. Then, the unit can
2181 * correctly enter the failed state later in mount_sigchld(). */
2182 mount_set_state(mount, MOUNT_MOUNTING);
2183 break;
2184
2185 default:
2186 break;
2187 }
2188
2189 } else if (mount->proc_flags & (MOUNT_PROC_JUST_MOUNTED|MOUNT_PROC_JUST_CHANGED)) {
2190
2191 /* A mount point was added or changed */
2192
2193 switch (mount->state) {
2194
2195 case MOUNT_DEAD:
2196 case MOUNT_FAILED:
2197
2198 /* This has just been mounted by somebody else, follow the state change, but let's
2199 * generate a new invocation ID for this implicitly and automatically. */
2200 (void) unit_acquire_invocation_id(u);
2201 mount_cycle_clear(mount);
2202 mount_enter_mounted(mount, MOUNT_SUCCESS);
2203 break;
2204
2205 case MOUNT_MOUNTING:
2206 mount_set_state(mount, MOUNT_MOUNTING_DONE);
2207 break;
2208
2209 default:
2210 /* Nothing really changed, but let's issue an notification call nonetheless,
2211 * in case somebody is waiting for this. (e.g. file system ro/rw
2212 * remounts.) */
2213 mount_set_state(mount, mount->state);
2214 break;
2215 }
2216 }
2217
2218 if (mount_is_mounted(mount) &&
2219 mount->from_proc_self_mountinfo &&
2220 mount->parameters_proc_self_mountinfo.what)
2221 /* Track devices currently used */
2222 if (set_put_strdup_full(&around, &path_hash_ops_free, mount->parameters_proc_self_mountinfo.what) < 0)
2223 log_oom();
2224
2225 /* Reset the flags for later calls */
2226 mount->proc_flags = 0;
2227 }
2228
2229 SET_FOREACH(what, gone) {
2230 if (set_contains(around, what))
2231 continue;
2232
2233 /* Let the device units know that the device is no longer mounted */
2234 device_found_node(m, what, DEVICE_NOT_FOUND, DEVICE_FOUND_MOUNT);
2235 }
2236
2237 return 0;
2238 }
2239
2240 static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
2241 Manager *m = ASSERT_PTR(userdata);
2242
2243 assert(revents & EPOLLIN);
2244
2245 return mount_process_proc_self_mountinfo(m);
2246 }
2247
2248 int mount_invalidate_state_by_path(Manager *manager, const char *path) {
2249 _cleanup_free_ char *name = NULL;
2250 Unit *u;
2251 int r;
2252
2253 assert(manager);
2254 assert(path);
2255
2256 r = unit_name_from_path(path, ".mount", &name);
2257 if (r < 0)
2258 return log_debug_errno(r, "Failed to generate unit name from path \"%s\", ignoring: %m", path);
2259
2260 u = manager_get_unit(manager, name);
2261 if (!u)
2262 return -ENOENT;
2263
2264 MOUNT(u)->invalidated_state = true;
2265 return 0;
2266 }
2267
2268 static void mount_reset_failed(Unit *u) {
2269 Mount *m = MOUNT(u);
2270
2271 assert(m);
2272
2273 if (m->state == MOUNT_FAILED)
2274 mount_set_state(m, MOUNT_DEAD);
2275
2276 m->result = MOUNT_SUCCESS;
2277 m->reload_result = MOUNT_SUCCESS;
2278 m->clean_result = MOUNT_SUCCESS;
2279 }
2280
2281 static PidRef* mount_control_pid(Unit *u) {
2282 return &ASSERT_PTR(MOUNT(u))->control_pid;
2283 }
2284
2285 static int mount_clean(Unit *u, ExecCleanMask mask) {
2286 _cleanup_strv_free_ char **l = NULL;
2287 Mount *m = MOUNT(u);
2288 int r;
2289
2290 assert(m);
2291 assert(mask != 0);
2292
2293 if (m->state != MOUNT_DEAD)
2294 return -EBUSY;
2295
2296 r = exec_context_get_clean_directories(&m->exec_context, u->manager->prefix, mask, &l);
2297 if (r < 0)
2298 return r;
2299
2300 if (strv_isempty(l))
2301 return -EUNATCH;
2302
2303 mount_unwatch_control_pid(m);
2304 m->clean_result = MOUNT_SUCCESS;
2305 m->control_command = NULL;
2306 m->control_command_id = _MOUNT_EXEC_COMMAND_INVALID;
2307
2308 r = mount_arm_timer(m, usec_add(now(CLOCK_MONOTONIC), m->exec_context.timeout_clean_usec));
2309 if (r < 0) {
2310 log_unit_warning_errno(u, r, "Failed to install timer: %m");
2311 goto fail;
2312 }
2313
2314 r = unit_fork_and_watch_rm_rf(u, l, &m->control_pid);
2315 if (r < 0) {
2316 log_unit_warning_errno(u, r, "Failed to spawn cleaning task: %m");
2317 goto fail;
2318 }
2319
2320 mount_set_state(m, MOUNT_CLEANING);
2321 return 0;
2322
2323 fail:
2324 m->clean_result = MOUNT_FAILURE_RESOURCES;
2325 m->timer_event_source = sd_event_source_disable_unref(m->timer_event_source);
2326 return r;
2327 }
2328
2329 static int mount_can_clean(Unit *u, ExecCleanMask *ret) {
2330 Mount *m = MOUNT(u);
2331
2332 assert(m);
2333
2334 return exec_context_get_clean_mask(&m->exec_context, ret);
2335 }
2336
2337 static int mount_can_start(Unit *u) {
2338 Mount *m = MOUNT(u);
2339 int r;
2340
2341 assert(m);
2342
2343 r = unit_test_start_limit(u);
2344 if (r < 0) {
2345 mount_enter_dead(m, MOUNT_FAILURE_START_LIMIT_HIT);
2346 return r;
2347 }
2348
2349 return 1;
2350 }
2351
2352 static int mount_subsystem_ratelimited(Manager *m) {
2353 assert(m);
2354
2355 if (!m->mount_event_source)
2356 return false;
2357
2358 return sd_event_source_is_ratelimited(m->mount_event_source);
2359 }
2360
2361 static const char* const mount_exec_command_table[_MOUNT_EXEC_COMMAND_MAX] = {
2362 [MOUNT_EXEC_MOUNT] = "ExecMount",
2363 [MOUNT_EXEC_UNMOUNT] = "ExecUnmount",
2364 [MOUNT_EXEC_REMOUNT] = "ExecRemount",
2365 };
2366
2367 DEFINE_STRING_TABLE_LOOKUP(mount_exec_command, MountExecCommand);
2368
2369 static const char* const mount_result_table[_MOUNT_RESULT_MAX] = {
2370 [MOUNT_SUCCESS] = "success",
2371 [MOUNT_FAILURE_RESOURCES] = "resources",
2372 [MOUNT_FAILURE_TIMEOUT] = "timeout",
2373 [MOUNT_FAILURE_EXIT_CODE] = "exit-code",
2374 [MOUNT_FAILURE_SIGNAL] = "signal",
2375 [MOUNT_FAILURE_CORE_DUMP] = "core-dump",
2376 [MOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
2377 [MOUNT_FAILURE_PROTOCOL] = "protocol",
2378 };
2379
2380 DEFINE_STRING_TABLE_LOOKUP(mount_result, MountResult);
2381
2382 const UnitVTable mount_vtable = {
2383 .object_size = sizeof(Mount),
2384 .exec_context_offset = offsetof(Mount, exec_context),
2385 .cgroup_context_offset = offsetof(Mount, cgroup_context),
2386 .kill_context_offset = offsetof(Mount, kill_context),
2387 .exec_runtime_offset = offsetof(Mount, exec_runtime),
2388
2389 .sections =
2390 "Unit\0"
2391 "Mount\0"
2392 "Install\0",
2393 .private_section = "Mount",
2394
2395 .can_transient = true,
2396 .can_fail = true,
2397 .exclude_from_switch_root_serialization = true,
2398
2399 .init = mount_init,
2400 .load = mount_load,
2401 .done = mount_done,
2402
2403 .coldplug = mount_coldplug,
2404 .catchup = mount_catchup,
2405
2406 .dump = mount_dump,
2407
2408 .start = mount_start,
2409 .stop = mount_stop,
2410 .reload = mount_reload,
2411
2412 .clean = mount_clean,
2413 .can_clean = mount_can_clean,
2414
2415 .serialize = mount_serialize,
2416 .deserialize_item = mount_deserialize_item,
2417
2418 .active_state = mount_active_state,
2419 .sub_state_to_string = mount_sub_state_to_string,
2420
2421 .will_restart = unit_will_restart_default,
2422
2423 .may_gc = mount_may_gc,
2424 .is_extrinsic = mount_is_extrinsic,
2425
2426 .sigchld_event = mount_sigchld_event,
2427
2428 .reset_failed = mount_reset_failed,
2429
2430 .control_pid = mount_control_pid,
2431
2432 .bus_set_property = bus_mount_set_property,
2433 .bus_commit_properties = bus_mount_commit_properties,
2434
2435 .get_timeout = mount_get_timeout,
2436
2437 .enumerate_perpetual = mount_enumerate_perpetual,
2438 .enumerate = mount_enumerate,
2439 .shutdown = mount_shutdown,
2440 .subsystem_ratelimited = mount_subsystem_ratelimited,
2441
2442 .status_message_formats = {
2443 .starting_stopping = {
2444 [0] = "Mounting %s...",
2445 [1] = "Unmounting %s...",
2446 },
2447 .finished_start_job = {
2448 [JOB_DONE] = "Mounted %s.",
2449 [JOB_FAILED] = "Failed to mount %s.",
2450 [JOB_TIMEOUT] = "Timed out mounting %s.",
2451 },
2452 .finished_stop_job = {
2453 [JOB_DONE] = "Unmounted %s.",
2454 [JOB_FAILED] = "Failed unmounting %s.",
2455 [JOB_TIMEOUT] = "Timed out unmounting %s.",
2456 },
2457 },
2458
2459 .can_start = mount_can_start,
2460
2461 .notify_plymouth = true,
2462 };
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