1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 #include <sys/inotify.h>
23 #include <sys/epoll.h>
24 #include <sys/ioctl.h>
29 #include "unit-name.h"
32 #include "dbus-path.h"
34 #include "path-util.h"
37 #include "bus-error.h"
39 static const UnitActiveState state_translation_table
[_PATH_STATE_MAX
] = {
40 [PATH_DEAD
] = UNIT_INACTIVE
,
41 [PATH_WAITING
] = UNIT_ACTIVE
,
42 [PATH_RUNNING
] = UNIT_ACTIVE
,
43 [PATH_FAILED
] = UNIT_FAILED
46 static int path_dispatch_io(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
);
48 int path_spec_watch(PathSpec
*s
, sd_event_io_handler_t handler
) {
50 static const int flags_table
[_PATH_TYPE_MAX
] = {
51 [PATH_EXISTS
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
,
52 [PATH_EXISTS_GLOB
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
,
53 [PATH_CHANGED
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
|IN_CLOSE_WRITE
|IN_CREATE
|IN_DELETE
|IN_MOVED_FROM
|IN_MOVED_TO
,
54 [PATH_MODIFIED
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
|IN_CLOSE_WRITE
|IN_CREATE
|IN_DELETE
|IN_MOVED_FROM
|IN_MOVED_TO
|IN_MODIFY
,
55 [PATH_DIRECTORY_NOT_EMPTY
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
|IN_CREATE
|IN_MOVED_TO
59 char *slash
, *oldslash
= NULL
;
68 s
->inotify_fd
= inotify_init1(IN_NONBLOCK
|IN_CLOEXEC
);
69 if (s
->inotify_fd
< 0) {
74 r
= sd_event_add_io(s
->unit
->manager
->event
, &s
->event_source
, s
->inotify_fd
, EPOLLIN
, handler
, s
);
78 /* This assumes the path was passed through path_kill_slashes()! */
80 for (slash
= strchr(s
->path
, '/'); ; slash
= strchr(slash
+1, '/')) {
86 cut
= slash
+ (slash
== s
->path
);
90 flags
= IN_MOVE_SELF
| IN_DELETE_SELF
| IN_ATTRIB
| IN_CREATE
| IN_MOVED_TO
;
92 flags
= flags_table
[s
->type
];
94 r
= inotify_add_watch(s
->inotify_fd
, s
->path
, flags
);
96 if (errno
== EACCES
|| errno
== ENOENT
) {
102 log_warning("Failed to add watch on %s: %s", s
->path
,
103 errno
== ENOSPC
? "too many watches" : strerror(-r
));
111 /* Path exists, we don't need to watch parent
114 char *cut2
= oldslash
+ (oldslash
== s
->path
);
118 inotify_add_watch(s
->inotify_fd
, s
->path
, IN_MOVE_SELF
);
119 /* Error is ignored, the worst can happen is
120 we get spurious events. */
132 /* whole path has been iterated over */
139 log_error_errno(errno
, "Failed to add watch on any of the components of %s: %m",
141 r
= -errno
; /* either EACCESS or ENOENT */
148 path_spec_unwatch(s
);
152 void path_spec_unwatch(PathSpec
*s
) {
155 s
->event_source
= sd_event_source_unref(s
->event_source
);
156 s
->inotify_fd
= safe_close(s
->inotify_fd
);
159 int path_spec_fd_event(PathSpec
*s
, uint32_t revents
) {
160 _cleanup_free_
uint8_t *buf
= NULL
;
161 struct inotify_event
*e
;
166 if (revents
!= EPOLLIN
) {
167 log_error("Got invalid poll event on inotify.");
171 if (ioctl(s
->inotify_fd
, FIONREAD
, &l
) < 0)
172 return log_error_errno(errno
, "FIONREAD failed: %m");
180 k
= read(s
->inotify_fd
, buf
, l
);
182 return log_error_errno(errno
, "Failed to read inotify event: %m");
184 e
= (struct inotify_event
*) buf
;
189 if ((s
->type
== PATH_CHANGED
|| s
->type
== PATH_MODIFIED
) &&
190 s
->primary_wd
== e
->wd
)
193 step
= sizeof(struct inotify_event
) + e
->len
;
194 assert(step
<= (size_t) k
);
196 e
= (struct inotify_event
*) ((uint8_t*) e
+ step
);
203 static bool path_spec_check_good(PathSpec
*s
, bool initial
) {
209 good
= access(s
->path
, F_OK
) >= 0;
212 case PATH_EXISTS_GLOB
:
213 good
= glob_exists(s
->path
) > 0;
216 case PATH_DIRECTORY_NOT_EMPTY
: {
219 k
= dir_is_empty(s
->path
);
220 good
= !(k
== -ENOENT
|| k
> 0);
225 case PATH_MODIFIED
: {
228 b
= access(s
->path
, F_OK
) >= 0;
229 good
= !initial
&& b
!= s
->previous_exists
;
230 s
->previous_exists
= b
;
241 static void path_spec_mkdir(PathSpec
*s
, mode_t mode
) {
244 if (s
->type
== PATH_EXISTS
|| s
->type
== PATH_EXISTS_GLOB
)
247 r
= mkdir_p_label(s
->path
, mode
);
249 log_warning_errno(r
, "mkdir(%s) failed: %m", s
->path
);
252 static void path_spec_dump(PathSpec
*s
, FILE *f
, const char *prefix
) {
256 path_type_to_string(s
->type
),
260 void path_spec_done(PathSpec
*s
) {
262 assert(s
->inotify_fd
== -1);
267 static void path_init(Unit
*u
) {
271 assert(u
->load_state
== UNIT_STUB
);
273 p
->directory_mode
= 0755;
276 void path_free_specs(Path
*p
) {
281 while ((s
= p
->specs
)) {
282 path_spec_unwatch(s
);
283 LIST_REMOVE(spec
, p
->specs
, s
);
289 static void path_done(Unit
*u
) {
297 static int path_add_mount_links(Path
*p
) {
303 LIST_FOREACH(spec
, s
, p
->specs
) {
304 r
= unit_require_mounts_for(UNIT(p
), s
->path
);
312 static int path_verify(Path
*p
) {
315 if (UNIT(p
)->load_state
!= UNIT_LOADED
)
319 log_unit_error(UNIT(p
)->id
,
320 "%s lacks path setting. Refusing.", UNIT(p
)->id
);
327 static int path_add_default_dependencies(Path
*p
) {
332 r
= unit_add_dependency_by_name(UNIT(p
), UNIT_BEFORE
,
333 SPECIAL_PATHS_TARGET
, NULL
, true);
337 if (UNIT(p
)->manager
->running_as
== SYSTEMD_SYSTEM
) {
338 r
= unit_add_two_dependencies_by_name(UNIT(p
), UNIT_AFTER
, UNIT_REQUIRES
,
339 SPECIAL_SYSINIT_TARGET
, NULL
, true);
344 return unit_add_two_dependencies_by_name(UNIT(p
), UNIT_BEFORE
, UNIT_CONFLICTS
,
345 SPECIAL_SHUTDOWN_TARGET
, NULL
, true);
348 static int path_load(Unit
*u
) {
353 assert(u
->load_state
== UNIT_STUB
);
355 r
= unit_load_fragment_and_dropin(u
);
359 if (u
->load_state
== UNIT_LOADED
) {
361 if (set_isempty(u
->dependencies
[UNIT_TRIGGERS
])) {
364 r
= unit_load_related_unit(u
, ".service", &x
);
368 r
= unit_add_two_dependencies(u
, UNIT_BEFORE
, UNIT_TRIGGERS
, x
, true);
373 r
= path_add_mount_links(p
);
377 if (UNIT(p
)->default_dependencies
) {
378 r
= path_add_default_dependencies(p
);
384 return path_verify(p
);
387 static void path_dump(Unit
*u
, FILE *f
, const char *prefix
) {
395 trigger
= UNIT_TRIGGER(u
);
401 "%sMakeDirectory: %s\n"
402 "%sDirectoryMode: %04o\n",
403 prefix
, path_state_to_string(p
->state
),
404 prefix
, path_result_to_string(p
->result
),
405 prefix
, trigger
? trigger
->id
: "n/a",
406 prefix
, yes_no(p
->make_directory
),
407 prefix
, p
->directory_mode
);
409 LIST_FOREACH(spec
, s
, p
->specs
)
410 path_spec_dump(s
, f
, prefix
);
413 static void path_unwatch(Path
*p
) {
418 LIST_FOREACH(spec
, s
, p
->specs
)
419 path_spec_unwatch(s
);
422 static int path_watch(Path
*p
) {
428 LIST_FOREACH(spec
, s
, p
->specs
) {
429 r
= path_spec_watch(s
, path_dispatch_io
);
437 static void path_set_state(Path
*p
, PathState state
) {
441 old_state
= p
->state
;
444 if (state
!= PATH_WAITING
&&
445 (state
!= PATH_RUNNING
|| p
->inotify_triggered
))
448 if (state
!= old_state
)
449 log_debug("%s changed %s -> %s",
451 path_state_to_string(old_state
),
452 path_state_to_string(state
));
454 unit_notify(UNIT(p
), state_translation_table
[old_state
], state_translation_table
[state
], true);
457 static void path_enter_waiting(Path
*p
, bool initial
, bool recheck
);
459 static int path_coldplug(Unit
*u
) {
463 assert(p
->state
== PATH_DEAD
);
465 if (p
->deserialized_state
!= p
->state
) {
467 if (p
->deserialized_state
== PATH_WAITING
||
468 p
->deserialized_state
== PATH_RUNNING
)
469 path_enter_waiting(p
, true, true);
471 path_set_state(p
, p
->deserialized_state
);
477 static void path_enter_dead(Path
*p
, PathResult f
) {
480 if (f
!= PATH_SUCCESS
)
483 path_set_state(p
, p
->result
!= PATH_SUCCESS
? PATH_FAILED
: PATH_DEAD
);
486 static void path_enter_running(Path
*p
) {
487 _cleanup_bus_error_free_ sd_bus_error error
= SD_BUS_ERROR_NULL
;
492 /* Don't start job if we are supposed to go down */
493 if (unit_stop_pending(UNIT(p
)))
496 r
= manager_add_job(UNIT(p
)->manager
, JOB_START
, UNIT_TRIGGER(UNIT(p
)),
497 JOB_REPLACE
, true, &error
, NULL
);
501 p
->inotify_triggered
= false;
507 path_set_state(p
, PATH_RUNNING
);
511 log_warning("%s failed to queue unit startup job: %s",
512 UNIT(p
)->id
, bus_error_message(&error
, r
));
513 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
516 static bool path_check_good(Path
*p
, bool initial
) {
522 LIST_FOREACH(spec
, s
, p
->specs
) {
523 good
= path_spec_check_good(s
, initial
);
532 static void path_enter_waiting(Path
*p
, bool initial
, bool recheck
) {
536 if (path_check_good(p
, initial
)) {
537 log_debug("%s got triggered.", UNIT(p
)->id
);
538 path_enter_running(p
);
546 /* Hmm, so now we have created inotify watches, but the file
547 * might have appeared/been removed by now, so we must
551 if (path_check_good(p
, false)) {
552 log_debug("%s got triggered.", UNIT(p
)->id
);
553 path_enter_running(p
);
557 path_set_state(p
, PATH_WAITING
);
561 log_warning_errno(r
, "%s failed to enter waiting state: %m", UNIT(p
)->id
);
562 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
565 static void path_mkdir(Path
*p
) {
570 if (!p
->make_directory
)
573 LIST_FOREACH(spec
, s
, p
->specs
)
574 path_spec_mkdir(s
, p
->directory_mode
);
577 static int path_start(Unit
*u
) {
581 assert(p
->state
== PATH_DEAD
|| p
->state
== PATH_FAILED
);
583 if (UNIT_TRIGGER(u
)->load_state
!= UNIT_LOADED
)
588 p
->result
= PATH_SUCCESS
;
589 path_enter_waiting(p
, true, true);
594 static int path_stop(Unit
*u
) {
598 assert(p
->state
== PATH_WAITING
|| p
->state
== PATH_RUNNING
);
600 path_enter_dead(p
, PATH_SUCCESS
);
604 static int path_serialize(Unit
*u
, FILE *f
, FDSet
*fds
) {
611 unit_serialize_item(u
, f
, "state", path_state_to_string(p
->state
));
612 unit_serialize_item(u
, f
, "result", path_result_to_string(p
->result
));
617 static int path_deserialize_item(Unit
*u
, const char *key
, const char *value
, FDSet
*fds
) {
625 if (streq(key
, "state")) {
628 state
= path_state_from_string(value
);
630 log_debug("Failed to parse state value %s", value
);
632 p
->deserialized_state
= state
;
634 } else if (streq(key
, "result")) {
637 f
= path_result_from_string(value
);
639 log_debug("Failed to parse result value %s", value
);
640 else if (f
!= PATH_SUCCESS
)
644 log_debug("Unknown serialization key '%s'", key
);
649 _pure_
static UnitActiveState
path_active_state(Unit
*u
) {
652 return state_translation_table
[PATH(u
)->state
];
655 _pure_
static const char *path_sub_state_to_string(Unit
*u
) {
658 return path_state_to_string(PATH(u
)->state
);
661 static int path_dispatch_io(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
) {
662 PathSpec
*s
= userdata
;
672 if (p
->state
!= PATH_WAITING
&&
673 p
->state
!= PATH_RUNNING
)
676 /* log_debug("inotify wakeup on %s.", u->id); */
678 LIST_FOREACH(spec
, s
, p
->specs
)
679 if (path_spec_owns_inotify_fd(s
, fd
))
683 log_error("Got event on unknown fd.");
687 changed
= path_spec_fd_event(s
, revents
);
691 /* If we are already running, then remember that one event was
692 * dispatched so that we restart the service only if something
693 * actually changed on disk */
694 p
->inotify_triggered
= true;
697 path_enter_running(p
);
699 path_enter_waiting(p
, false, true);
704 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
708 static void path_trigger_notify(Unit
*u
, Unit
*other
) {
714 /* Invoked whenever the unit we trigger changes state or gains
717 if (other
->load_state
!= UNIT_LOADED
)
720 if (p
->state
== PATH_RUNNING
&&
721 UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other
))) {
722 log_unit_debug(UNIT(p
)->id
,
723 "%s got notified about unit deactivation.",
726 /* Hmm, so inotify was triggered since the
727 * last activation, so I guess we need to
728 * recheck what is going on. */
729 path_enter_waiting(p
, false, p
->inotify_triggered
);
733 static void path_reset_failed(Unit
*u
) {
738 if (p
->state
== PATH_FAILED
)
739 path_set_state(p
, PATH_DEAD
);
741 p
->result
= PATH_SUCCESS
;
744 static const char* const path_state_table
[_PATH_STATE_MAX
] = {
745 [PATH_DEAD
] = "dead",
746 [PATH_WAITING
] = "waiting",
747 [PATH_RUNNING
] = "running",
748 [PATH_FAILED
] = "failed"
751 DEFINE_STRING_TABLE_LOOKUP(path_state
, PathState
);
753 static const char* const path_type_table
[_PATH_TYPE_MAX
] = {
754 [PATH_EXISTS
] = "PathExists",
755 [PATH_EXISTS_GLOB
] = "PathExistsGlob",
756 [PATH_DIRECTORY_NOT_EMPTY
] = "DirectoryNotEmpty",
757 [PATH_CHANGED
] = "PathChanged",
758 [PATH_MODIFIED
] = "PathModified",
761 DEFINE_STRING_TABLE_LOOKUP(path_type
, PathType
);
763 static const char* const path_result_table
[_PATH_RESULT_MAX
] = {
764 [PATH_SUCCESS
] = "success",
765 [PATH_FAILURE_RESOURCES
] = "resources",
768 DEFINE_STRING_TABLE_LOOKUP(path_result
, PathResult
);
770 const UnitVTable path_vtable
= {
771 .object_size
= sizeof(Path
),
782 .coldplug
= path_coldplug
,
789 .serialize
= path_serialize
,
790 .deserialize_item
= path_deserialize_item
,
792 .active_state
= path_active_state
,
793 .sub_state_to_string
= path_sub_state_to_string
,
795 .trigger_notify
= path_trigger_notify
,
797 .reset_failed
= path_reset_failed
,
799 .bus_interface
= "org.freedesktop.systemd1.Path",
800 .bus_vtable
= bus_path_vtable