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/>.
23 #include <sys/epoll.h>
24 #include <sys/inotify.h>
27 #include "bus-error.h"
29 #include "dbus-path.h"
35 #include "stat-util.h"
36 #include "string-table.h"
37 #include "string-util.h"
38 #include "unit-name.h"
41 static const UnitActiveState state_translation_table
[_PATH_STATE_MAX
] = {
42 [PATH_DEAD
] = UNIT_INACTIVE
,
43 [PATH_WAITING
] = UNIT_ACTIVE
,
44 [PATH_RUNNING
] = UNIT_ACTIVE
,
45 [PATH_FAILED
] = UNIT_FAILED
48 static int path_dispatch_io(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
);
50 int path_spec_watch(PathSpec
*s
, sd_event_io_handler_t handler
) {
52 static const int flags_table
[_PATH_TYPE_MAX
] = {
53 [PATH_EXISTS
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
,
54 [PATH_EXISTS_GLOB
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
,
55 [PATH_CHANGED
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
|IN_CLOSE_WRITE
|IN_CREATE
|IN_DELETE
|IN_MOVED_FROM
|IN_MOVED_TO
,
56 [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
,
57 [PATH_DIRECTORY_NOT_EMPTY
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
|IN_CREATE
|IN_MOVED_TO
61 char *slash
, *oldslash
= NULL
;
70 s
->inotify_fd
= inotify_init1(IN_NONBLOCK
|IN_CLOEXEC
);
71 if (s
->inotify_fd
< 0) {
76 r
= sd_event_add_io(s
->unit
->manager
->event
, &s
->event_source
, s
->inotify_fd
, EPOLLIN
, handler
, s
);
80 (void) sd_event_source_set_description(s
->event_source
, "path");
82 /* This assumes the path was passed through path_kill_slashes()! */
84 for (slash
= strchr(s
->path
, '/'); ; slash
= strchr(slash
+1, '/')) {
90 cut
= slash
+ (slash
== s
->path
);
94 flags
= IN_MOVE_SELF
| IN_DELETE_SELF
| IN_ATTRIB
| IN_CREATE
| IN_MOVED_TO
;
96 flags
= flags_table
[s
->type
];
98 r
= inotify_add_watch(s
->inotify_fd
, s
->path
, flags
);
100 if (errno
== EACCES
|| errno
== ENOENT
) {
106 r
= log_warning_errno(errno
, "Failed to add watch on %s: %s", s
->path
, errno
== ENOSPC
? "too many watches" : strerror(-r
));
113 /* Path exists, we don't need to watch parent
116 char *cut2
= oldslash
+ (oldslash
== s
->path
);
120 inotify_add_watch(s
->inotify_fd
, s
->path
, IN_MOVE_SELF
);
121 /* Error is ignored, the worst can happen is
122 we get spurious events. */
134 /* whole path has been iterated over */
141 r
= log_error_errno(errno
, "Failed to add watch on any of the components of %s: %m", s
->path
);
142 /* either EACCESS or ENOENT */
149 path_spec_unwatch(s
);
153 void path_spec_unwatch(PathSpec
*s
) {
156 s
->event_source
= sd_event_source_unref(s
->event_source
);
157 s
->inotify_fd
= safe_close(s
->inotify_fd
);
160 int path_spec_fd_event(PathSpec
*s
, uint32_t revents
) {
161 union inotify_event_buffer buffer
;
162 struct inotify_event
*e
;
166 if (revents
!= EPOLLIN
) {
167 log_error("Got invalid poll event on inotify.");
171 l
= read(s
->inotify_fd
, &buffer
, sizeof(buffer
));
173 if (errno
== EAGAIN
|| errno
== EINTR
)
176 return log_error_errno(errno
, "Failed to read inotify event: %m");
179 FOREACH_INOTIFY_EVENT(e
, buffer
, l
) {
180 if ((s
->type
== PATH_CHANGED
|| s
->type
== PATH_MODIFIED
) &&
181 s
->primary_wd
== e
->wd
)
188 static bool path_spec_check_good(PathSpec
*s
, bool initial
) {
194 good
= access(s
->path
, F_OK
) >= 0;
197 case PATH_EXISTS_GLOB
:
198 good
= glob_exists(s
->path
) > 0;
201 case PATH_DIRECTORY_NOT_EMPTY
: {
204 k
= dir_is_empty(s
->path
);
205 good
= !(k
== -ENOENT
|| k
> 0);
210 case PATH_MODIFIED
: {
213 b
= access(s
->path
, F_OK
) >= 0;
214 good
= !initial
&& b
!= s
->previous_exists
;
215 s
->previous_exists
= b
;
226 static void path_spec_mkdir(PathSpec
*s
, mode_t mode
) {
229 if (s
->type
== PATH_EXISTS
|| s
->type
== PATH_EXISTS_GLOB
)
232 r
= mkdir_p_label(s
->path
, mode
);
234 log_warning_errno(r
, "mkdir(%s) failed: %m", s
->path
);
237 static void path_spec_dump(PathSpec
*s
, FILE *f
, const char *prefix
) {
241 path_type_to_string(s
->type
),
245 void path_spec_done(PathSpec
*s
) {
247 assert(s
->inotify_fd
== -1);
252 static void path_init(Unit
*u
) {
256 assert(u
->load_state
== UNIT_STUB
);
258 p
->directory_mode
= 0755;
261 void path_free_specs(Path
*p
) {
266 while ((s
= p
->specs
)) {
267 path_spec_unwatch(s
);
268 LIST_REMOVE(spec
, p
->specs
, s
);
274 static void path_done(Unit
*u
) {
282 static int path_add_mount_links(Path
*p
) {
288 LIST_FOREACH(spec
, s
, p
->specs
) {
289 r
= unit_require_mounts_for(UNIT(p
), s
->path
);
297 static int path_verify(Path
*p
) {
300 if (UNIT(p
)->load_state
!= UNIT_LOADED
)
304 log_unit_error(UNIT(p
), "Path unit lacks path setting. Refusing.");
311 static int path_add_default_dependencies(Path
*p
) {
316 r
= unit_add_dependency_by_name(UNIT(p
), UNIT_BEFORE
,
317 SPECIAL_PATHS_TARGET
, NULL
, true);
321 if (UNIT(p
)->manager
->running_as
== MANAGER_SYSTEM
) {
322 r
= unit_add_two_dependencies_by_name(UNIT(p
), UNIT_AFTER
, UNIT_REQUIRES
,
323 SPECIAL_SYSINIT_TARGET
, NULL
, true);
328 return unit_add_two_dependencies_by_name(UNIT(p
), UNIT_BEFORE
, UNIT_CONFLICTS
,
329 SPECIAL_SHUTDOWN_TARGET
, NULL
, true);
332 static int path_load(Unit
*u
) {
337 assert(u
->load_state
== UNIT_STUB
);
339 r
= unit_load_fragment_and_dropin(u
);
343 if (u
->load_state
== UNIT_LOADED
) {
345 if (set_isempty(u
->dependencies
[UNIT_TRIGGERS
])) {
348 r
= unit_load_related_unit(u
, ".service", &x
);
352 r
= unit_add_two_dependencies(u
, UNIT_BEFORE
, UNIT_TRIGGERS
, x
, true);
357 r
= path_add_mount_links(p
);
361 if (UNIT(p
)->default_dependencies
) {
362 r
= path_add_default_dependencies(p
);
368 return path_verify(p
);
371 static void path_dump(Unit
*u
, FILE *f
, const char *prefix
) {
379 trigger
= UNIT_TRIGGER(u
);
385 "%sMakeDirectory: %s\n"
386 "%sDirectoryMode: %04o\n",
387 prefix
, path_state_to_string(p
->state
),
388 prefix
, path_result_to_string(p
->result
),
389 prefix
, trigger
? trigger
->id
: "n/a",
390 prefix
, yes_no(p
->make_directory
),
391 prefix
, p
->directory_mode
);
393 LIST_FOREACH(spec
, s
, p
->specs
)
394 path_spec_dump(s
, f
, prefix
);
397 static void path_unwatch(Path
*p
) {
402 LIST_FOREACH(spec
, s
, p
->specs
)
403 path_spec_unwatch(s
);
406 static int path_watch(Path
*p
) {
412 LIST_FOREACH(spec
, s
, p
->specs
) {
413 r
= path_spec_watch(s
, path_dispatch_io
);
421 static void path_set_state(Path
*p
, PathState state
) {
425 old_state
= p
->state
;
428 if (state
!= PATH_WAITING
&&
429 (state
!= PATH_RUNNING
|| p
->inotify_triggered
))
432 if (state
!= old_state
)
433 log_unit_debug(UNIT(p
), "Changed %s -> %s", path_state_to_string(old_state
), path_state_to_string(state
));
435 unit_notify(UNIT(p
), state_translation_table
[old_state
], state_translation_table
[state
], true);
438 static void path_enter_waiting(Path
*p
, bool initial
, bool recheck
);
440 static int path_coldplug(Unit
*u
) {
444 assert(p
->state
== PATH_DEAD
);
446 if (p
->deserialized_state
!= p
->state
) {
448 if (p
->deserialized_state
== PATH_WAITING
||
449 p
->deserialized_state
== PATH_RUNNING
)
450 path_enter_waiting(p
, true, true);
452 path_set_state(p
, p
->deserialized_state
);
458 static void path_enter_dead(Path
*p
, PathResult f
) {
461 if (f
!= PATH_SUCCESS
)
464 path_set_state(p
, p
->result
!= PATH_SUCCESS
? PATH_FAILED
: PATH_DEAD
);
467 static void path_enter_running(Path
*p
) {
468 _cleanup_bus_error_free_ sd_bus_error error
= SD_BUS_ERROR_NULL
;
473 /* Don't start job if we are supposed to go down */
474 if (unit_stop_pending(UNIT(p
)))
477 r
= manager_add_job(UNIT(p
)->manager
, JOB_START
, UNIT_TRIGGER(UNIT(p
)),
478 JOB_REPLACE
, true, &error
, NULL
);
482 p
->inotify_triggered
= false;
488 path_set_state(p
, PATH_RUNNING
);
492 log_unit_warning(UNIT(p
), "Failed to queue unit startup job: %s", bus_error_message(&error
, r
));
493 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
496 static bool path_check_good(Path
*p
, bool initial
) {
502 LIST_FOREACH(spec
, s
, p
->specs
) {
503 good
= path_spec_check_good(s
, initial
);
512 static void path_enter_waiting(Path
*p
, bool initial
, bool recheck
) {
516 if (path_check_good(p
, initial
)) {
517 log_unit_debug(UNIT(p
), "Got triggered.");
518 path_enter_running(p
);
526 /* Hmm, so now we have created inotify watches, but the file
527 * might have appeared/been removed by now, so we must
531 if (path_check_good(p
, false)) {
532 log_unit_debug(UNIT(p
), "Got triggered.");
533 path_enter_running(p
);
537 path_set_state(p
, PATH_WAITING
);
541 log_unit_warning_errno(UNIT(p
), r
, "Failed to enter waiting state: %m");
542 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
545 static void path_mkdir(Path
*p
) {
550 if (!p
->make_directory
)
553 LIST_FOREACH(spec
, s
, p
->specs
)
554 path_spec_mkdir(s
, p
->directory_mode
);
557 static int path_start(Unit
*u
) {
561 assert(p
->state
== PATH_DEAD
|| p
->state
== PATH_FAILED
);
563 if (UNIT_TRIGGER(u
)->load_state
!= UNIT_LOADED
)
568 p
->result
= PATH_SUCCESS
;
569 path_enter_waiting(p
, true, true);
574 static int path_stop(Unit
*u
) {
578 assert(p
->state
== PATH_WAITING
|| p
->state
== PATH_RUNNING
);
580 path_enter_dead(p
, PATH_SUCCESS
);
584 static int path_serialize(Unit
*u
, FILE *f
, FDSet
*fds
) {
591 unit_serialize_item(u
, f
, "state", path_state_to_string(p
->state
));
592 unit_serialize_item(u
, f
, "result", path_result_to_string(p
->result
));
597 static int path_deserialize_item(Unit
*u
, const char *key
, const char *value
, FDSet
*fds
) {
605 if (streq(key
, "state")) {
608 state
= path_state_from_string(value
);
610 log_unit_debug(u
, "Failed to parse state value: %s", value
);
612 p
->deserialized_state
= state
;
614 } else if (streq(key
, "result")) {
617 f
= path_result_from_string(value
);
619 log_unit_debug(u
, "Failed to parse result value: %s", value
);
620 else if (f
!= PATH_SUCCESS
)
624 log_unit_debug(u
, "Unknown serialization key: %s", key
);
629 _pure_
static UnitActiveState
path_active_state(Unit
*u
) {
632 return state_translation_table
[PATH(u
)->state
];
635 _pure_
static const char *path_sub_state_to_string(Unit
*u
) {
638 return path_state_to_string(PATH(u
)->state
);
641 static int path_dispatch_io(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
) {
642 PathSpec
*s
= userdata
;
652 if (p
->state
!= PATH_WAITING
&&
653 p
->state
!= PATH_RUNNING
)
656 /* log_debug("inotify wakeup on %s.", u->id); */
658 LIST_FOREACH(spec
, s
, p
->specs
)
659 if (path_spec_owns_inotify_fd(s
, fd
))
663 log_error("Got event on unknown fd.");
667 changed
= path_spec_fd_event(s
, revents
);
671 /* If we are already running, then remember that one event was
672 * dispatched so that we restart the service only if something
673 * actually changed on disk */
674 p
->inotify_triggered
= true;
677 path_enter_running(p
);
679 path_enter_waiting(p
, false, true);
684 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
688 static void path_trigger_notify(Unit
*u
, Unit
*other
) {
694 /* Invoked whenever the unit we trigger changes state or gains
697 if (other
->load_state
!= UNIT_LOADED
)
700 if (p
->state
== PATH_RUNNING
&&
701 UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other
))) {
702 log_unit_debug(UNIT(p
), "Got notified about unit deactivation.");
704 /* Hmm, so inotify was triggered since the
705 * last activation, so I guess we need to
706 * recheck what is going on. */
707 path_enter_waiting(p
, false, p
->inotify_triggered
);
711 static void path_reset_failed(Unit
*u
) {
716 if (p
->state
== PATH_FAILED
)
717 path_set_state(p
, PATH_DEAD
);
719 p
->result
= PATH_SUCCESS
;
722 static const char* const path_type_table
[_PATH_TYPE_MAX
] = {
723 [PATH_EXISTS
] = "PathExists",
724 [PATH_EXISTS_GLOB
] = "PathExistsGlob",
725 [PATH_DIRECTORY_NOT_EMPTY
] = "DirectoryNotEmpty",
726 [PATH_CHANGED
] = "PathChanged",
727 [PATH_MODIFIED
] = "PathModified",
730 DEFINE_STRING_TABLE_LOOKUP(path_type
, PathType
);
732 static const char* const path_result_table
[_PATH_RESULT_MAX
] = {
733 [PATH_SUCCESS
] = "success",
734 [PATH_FAILURE_RESOURCES
] = "resources",
737 DEFINE_STRING_TABLE_LOOKUP(path_result
, PathResult
);
739 const UnitVTable path_vtable
= {
740 .object_size
= sizeof(Path
),
751 .coldplug
= path_coldplug
,
758 .serialize
= path_serialize
,
759 .deserialize_item
= path_deserialize_item
,
761 .active_state
= path_active_state
,
762 .sub_state_to_string
= path_sub_state_to_string
,
764 .trigger_notify
= path_trigger_notify
,
766 .reset_failed
= path_reset_failed
,
768 .bus_vtable
= bus_path_vtable