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"
32 #include "glob-util.h"
37 #include "stat-util.h"
38 #include "string-table.h"
39 #include "string-util.h"
40 #include "unit-name.h"
43 static const UnitActiveState state_translation_table
[_PATH_STATE_MAX
] = {
44 [PATH_DEAD
] = UNIT_INACTIVE
,
45 [PATH_WAITING
] = UNIT_ACTIVE
,
46 [PATH_RUNNING
] = UNIT_ACTIVE
,
47 [PATH_FAILED
] = UNIT_FAILED
50 static int path_dispatch_io(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
);
52 int path_spec_watch(PathSpec
*s
, sd_event_io_handler_t handler
) {
54 static const int flags_table
[_PATH_TYPE_MAX
] = {
55 [PATH_EXISTS
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
,
56 [PATH_EXISTS_GLOB
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
,
57 [PATH_CHANGED
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
|IN_CLOSE_WRITE
|IN_CREATE
|IN_DELETE
|IN_MOVED_FROM
|IN_MOVED_TO
,
58 [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
,
59 [PATH_DIRECTORY_NOT_EMPTY
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
|IN_CREATE
|IN_MOVED_TO
63 char *slash
, *oldslash
= NULL
;
72 s
->inotify_fd
= inotify_init1(IN_NONBLOCK
|IN_CLOEXEC
);
73 if (s
->inotify_fd
< 0) {
78 r
= sd_event_add_io(s
->unit
->manager
->event
, &s
->event_source
, s
->inotify_fd
, EPOLLIN
, handler
, s
);
82 (void) sd_event_source_set_description(s
->event_source
, "path");
84 /* This assumes the path was passed through path_kill_slashes()! */
86 for (slash
= strchr(s
->path
, '/'); ; slash
= strchr(slash
+1, '/')) {
92 cut
= slash
+ (slash
== s
->path
);
96 flags
= IN_MOVE_SELF
| IN_DELETE_SELF
| IN_ATTRIB
| IN_CREATE
| IN_MOVED_TO
;
98 flags
= flags_table
[s
->type
];
100 r
= inotify_add_watch(s
->inotify_fd
, s
->path
, flags
);
102 if (errno
== EACCES
|| errno
== ENOENT
) {
108 r
= log_warning_errno(errno
, "Failed to add watch on %s: %s", s
->path
, errno
== ENOSPC
? "too many watches" : strerror(-r
));
115 /* Path exists, we don't need to watch parent
118 char *cut2
= oldslash
+ (oldslash
== s
->path
);
122 inotify_add_watch(s
->inotify_fd
, s
->path
, IN_MOVE_SELF
);
123 /* Error is ignored, the worst can happen is
124 we get spurious events. */
136 /* whole path has been iterated over */
143 r
= log_error_errno(errno
, "Failed to add watch on any of the components of %s: %m", s
->path
);
144 /* either EACCESS or ENOENT */
151 path_spec_unwatch(s
);
155 void path_spec_unwatch(PathSpec
*s
) {
158 s
->event_source
= sd_event_source_unref(s
->event_source
);
159 s
->inotify_fd
= safe_close(s
->inotify_fd
);
162 int path_spec_fd_event(PathSpec
*s
, uint32_t revents
) {
163 union inotify_event_buffer buffer
;
164 struct inotify_event
*e
;
168 if (revents
!= EPOLLIN
) {
169 log_error("Got invalid poll event on inotify.");
173 l
= read(s
->inotify_fd
, &buffer
, sizeof(buffer
));
175 if (errno
== EAGAIN
|| errno
== EINTR
)
178 return log_error_errno(errno
, "Failed to read inotify event: %m");
181 FOREACH_INOTIFY_EVENT(e
, buffer
, l
) {
182 if ((s
->type
== PATH_CHANGED
|| s
->type
== PATH_MODIFIED
) &&
183 s
->primary_wd
== e
->wd
)
190 static bool path_spec_check_good(PathSpec
*s
, bool initial
) {
196 good
= access(s
->path
, F_OK
) >= 0;
199 case PATH_EXISTS_GLOB
:
200 good
= glob_exists(s
->path
) > 0;
203 case PATH_DIRECTORY_NOT_EMPTY
: {
206 k
= dir_is_empty(s
->path
);
207 good
= !(k
== -ENOENT
|| k
> 0);
212 case PATH_MODIFIED
: {
215 b
= access(s
->path
, F_OK
) >= 0;
216 good
= !initial
&& b
!= s
->previous_exists
;
217 s
->previous_exists
= b
;
228 static void path_spec_mkdir(PathSpec
*s
, mode_t mode
) {
231 if (s
->type
== PATH_EXISTS
|| s
->type
== PATH_EXISTS_GLOB
)
234 r
= mkdir_p_label(s
->path
, mode
);
236 log_warning_errno(r
, "mkdir(%s) failed: %m", s
->path
);
239 static void path_spec_dump(PathSpec
*s
, FILE *f
, const char *prefix
) {
243 path_type_to_string(s
->type
),
247 void path_spec_done(PathSpec
*s
) {
249 assert(s
->inotify_fd
== -1);
254 static void path_init(Unit
*u
) {
258 assert(u
->load_state
== UNIT_STUB
);
260 p
->directory_mode
= 0755;
263 void path_free_specs(Path
*p
) {
268 while ((s
= p
->specs
)) {
269 path_spec_unwatch(s
);
270 LIST_REMOVE(spec
, p
->specs
, s
);
276 static void path_done(Unit
*u
) {
284 static int path_add_mount_links(Path
*p
) {
290 LIST_FOREACH(spec
, s
, p
->specs
) {
291 r
= unit_require_mounts_for(UNIT(p
), s
->path
);
299 static int path_verify(Path
*p
) {
302 if (UNIT(p
)->load_state
!= UNIT_LOADED
)
306 log_unit_error(UNIT(p
), "Path unit lacks path setting. Refusing.");
313 static int path_add_default_dependencies(Path
*p
) {
318 if (!UNIT(p
)->default_dependencies
)
321 r
= unit_add_dependency_by_name(UNIT(p
), UNIT_BEFORE
, SPECIAL_PATHS_TARGET
, NULL
, true);
325 if (UNIT(p
)->manager
->running_as
== MANAGER_SYSTEM
) {
326 r
= unit_add_two_dependencies_by_name(UNIT(p
), UNIT_AFTER
, UNIT_REQUIRES
, SPECIAL_SYSINIT_TARGET
, NULL
, true);
331 return unit_add_two_dependencies_by_name(UNIT(p
), UNIT_BEFORE
, UNIT_CONFLICTS
, SPECIAL_SHUTDOWN_TARGET
, NULL
, true);
334 static int path_load(Unit
*u
) {
339 assert(u
->load_state
== UNIT_STUB
);
341 r
= unit_load_fragment_and_dropin(u
);
345 if (u
->load_state
== UNIT_LOADED
) {
347 if (set_isempty(u
->dependencies
[UNIT_TRIGGERS
])) {
350 r
= unit_load_related_unit(u
, ".service", &x
);
354 r
= unit_add_two_dependencies(u
, UNIT_BEFORE
, UNIT_TRIGGERS
, x
, true);
359 r
= path_add_mount_links(p
);
363 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
)), JOB_REPLACE
, &error
, NULL
);
481 p
->inotify_triggered
= false;
487 path_set_state(p
, PATH_RUNNING
);
491 log_unit_warning(UNIT(p
), "Failed to queue unit startup job: %s", bus_error_message(&error
, r
));
492 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
495 static bool path_check_good(Path
*p
, bool initial
) {
501 LIST_FOREACH(spec
, s
, p
->specs
) {
502 good
= path_spec_check_good(s
, initial
);
511 static void path_enter_waiting(Path
*p
, bool initial
, bool recheck
) {
515 if (path_check_good(p
, initial
)) {
516 log_unit_debug(UNIT(p
), "Got triggered.");
517 path_enter_running(p
);
525 /* Hmm, so now we have created inotify watches, but the file
526 * might have appeared/been removed by now, so we must
530 if (path_check_good(p
, false)) {
531 log_unit_debug(UNIT(p
), "Got triggered.");
532 path_enter_running(p
);
536 path_set_state(p
, PATH_WAITING
);
540 log_unit_warning_errno(UNIT(p
), r
, "Failed to enter waiting state: %m");
541 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
544 static void path_mkdir(Path
*p
) {
549 if (!p
->make_directory
)
552 LIST_FOREACH(spec
, s
, p
->specs
)
553 path_spec_mkdir(s
, p
->directory_mode
);
556 static int path_start(Unit
*u
) {
560 assert(p
->state
== PATH_DEAD
|| p
->state
== PATH_FAILED
);
562 if (UNIT_TRIGGER(u
)->load_state
!= UNIT_LOADED
)
567 p
->result
= PATH_SUCCESS
;
568 path_enter_waiting(p
, true, true);
573 static int path_stop(Unit
*u
) {
577 assert(p
->state
== PATH_WAITING
|| p
->state
== PATH_RUNNING
);
579 path_enter_dead(p
, PATH_SUCCESS
);
583 static int path_serialize(Unit
*u
, FILE *f
, FDSet
*fds
) {
590 unit_serialize_item(u
, f
, "state", path_state_to_string(p
->state
));
591 unit_serialize_item(u
, f
, "result", path_result_to_string(p
->result
));
596 static int path_deserialize_item(Unit
*u
, const char *key
, const char *value
, FDSet
*fds
) {
604 if (streq(key
, "state")) {
607 state
= path_state_from_string(value
);
609 log_unit_debug(u
, "Failed to parse state value: %s", value
);
611 p
->deserialized_state
= state
;
613 } else if (streq(key
, "result")) {
616 f
= path_result_from_string(value
);
618 log_unit_debug(u
, "Failed to parse result value: %s", value
);
619 else if (f
!= PATH_SUCCESS
)
623 log_unit_debug(u
, "Unknown serialization key: %s", key
);
628 _pure_
static UnitActiveState
path_active_state(Unit
*u
) {
631 return state_translation_table
[PATH(u
)->state
];
634 _pure_
static const char *path_sub_state_to_string(Unit
*u
) {
637 return path_state_to_string(PATH(u
)->state
);
640 static int path_dispatch_io(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
) {
641 PathSpec
*s
= userdata
;
651 if (p
->state
!= PATH_WAITING
&&
652 p
->state
!= PATH_RUNNING
)
655 /* log_debug("inotify wakeup on %s.", u->id); */
657 LIST_FOREACH(spec
, s
, p
->specs
)
658 if (path_spec_owns_inotify_fd(s
, fd
))
662 log_error("Got event on unknown fd.");
666 changed
= path_spec_fd_event(s
, revents
);
670 /* If we are already running, then remember that one event was
671 * dispatched so that we restart the service only if something
672 * actually changed on disk */
673 p
->inotify_triggered
= true;
676 path_enter_running(p
);
678 path_enter_waiting(p
, false, true);
683 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
687 static void path_trigger_notify(Unit
*u
, Unit
*other
) {
693 /* Invoked whenever the unit we trigger changes state or gains
696 if (other
->load_state
!= UNIT_LOADED
)
699 if (p
->state
== PATH_RUNNING
&&
700 UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other
))) {
701 log_unit_debug(UNIT(p
), "Got notified about unit deactivation.");
703 /* Hmm, so inotify was triggered since the
704 * last activation, so I guess we need to
705 * recheck what is going on. */
706 path_enter_waiting(p
, false, p
->inotify_triggered
);
710 static void path_reset_failed(Unit
*u
) {
715 if (p
->state
== PATH_FAILED
)
716 path_set_state(p
, PATH_DEAD
);
718 p
->result
= PATH_SUCCESS
;
721 static const char* const path_type_table
[_PATH_TYPE_MAX
] = {
722 [PATH_EXISTS
] = "PathExists",
723 [PATH_EXISTS_GLOB
] = "PathExistsGlob",
724 [PATH_DIRECTORY_NOT_EMPTY
] = "DirectoryNotEmpty",
725 [PATH_CHANGED
] = "PathChanged",
726 [PATH_MODIFIED
] = "PathModified",
729 DEFINE_STRING_TABLE_LOOKUP(path_type
, PathType
);
731 static const char* const path_result_table
[_PATH_RESULT_MAX
] = {
732 [PATH_SUCCESS
] = "success",
733 [PATH_FAILURE_RESOURCES
] = "resources",
736 DEFINE_STRING_TABLE_LOOKUP(path_result
, PathResult
);
738 const UnitVTable path_vtable
= {
739 .object_size
= sizeof(Path
),
750 .coldplug
= path_coldplug
,
757 .serialize
= path_serialize
,
758 .deserialize_item
= path_deserialize_item
,
760 .active_state
= path_active_state
,
761 .sub_state_to_string
= path_sub_state_to_string
,
763 .trigger_notify
= path_trigger_notify
,
765 .reset_failed
= path_reset_failed
,
767 .bus_vtable
= bus_path_vtable