Fork of Original Code Base: anongit.freedesktop.org/systemd

This is the initial fork of the code base from freedsktop.org.
The code is provided here as a reference of the initial starting
point and for possible future checkouts after a large portion
of this code is removed.

Merge git://anongit.freedesktop.org/systemd/systemd

1 files changed, 773 insertions, 0 deletions

diff --git a/src/core/path.c b/src/core/path.c
new file mode 100644
index 0000000000..3936971b41
--- /dev/null
+++ b/src/core/path.c
@@ -0,0 +1,773 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/inotify.h>
+#include <sys/epoll.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <unistd.h>
+
+#include "unit.h"
+#include "unit-name.h"
+#include "path.h"
+#include "mkdir.h"
+#include "dbus-path.h"
+#include "special.h"
+#include "bus-errors.h"
+#include "path-util.h"
+
+static const UnitActiveState state_translation_table[_PATH_STATE_MAX] = {
+        [PATH_DEAD] = UNIT_INACTIVE,
+        [PATH_WAITING] = UNIT_ACTIVE,
+        [PATH_RUNNING] = UNIT_ACTIVE,
+        [PATH_FAILED] = UNIT_FAILED
+};
+
+int path_spec_watch(PathSpec *s, Unit *u) {
+
+        static const int flags_table[_PATH_TYPE_MAX] = {
+                [PATH_EXISTS] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB,
+                [PATH_EXISTS_GLOB] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB,
+                [PATH_CHANGED] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO,
+                [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,
+                [PATH_DIRECTORY_NOT_EMPTY] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CREATE|IN_MOVED_TO
+        };
+
+        bool exists = false;
+        char *k, *slash;
+        int r;
+
+        assert(u);
+        assert(s);
+
+        path_spec_unwatch(s, u);
+
+        if (!(k = strdup(s->path)))
+                return -ENOMEM;
+
+        if ((s->inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC)) < 0) {
+                r = -errno;
+                goto fail;
+        }
+
+        if (unit_watch_fd(u, s->inotify_fd, EPOLLIN, &s->watch) < 0) {
+                r = -errno;
+                goto fail;
+        }
+
+        s->primary_wd = inotify_add_watch(s->inotify_fd, k, flags_table[s->type]);
+        if (s->primary_wd >= 0)
+                exists = true;
+
+        do {
+                int flags;
+
+                /* This assumes the path was passed through path_kill_slashes()! */
+                slash = strrchr(k, '/');
+                if (!slash)
+                        break;
+
+                /* Trim the path at the last slash. Keep the slash if it's the root dir. */
+                slash[slash == k] = 0;
+
+                flags = IN_MOVE_SELF;
+                if (!exists)
+                        flags |= IN_DELETE_SELF | IN_ATTRIB | IN_CREATE | IN_MOVED_TO;
+
+                if (inotify_add_watch(s->inotify_fd, k, flags) >= 0)
+                        exists = true;
+        } while (slash != k);
+
+        return 0;
+
+fail:
+        free(k);
+
+        path_spec_unwatch(s, u);
+        return r;
+}
+
+void path_spec_unwatch(PathSpec *s, Unit *u) {
+
+        if (s->inotify_fd < 0)
+                return;
+
+        unit_unwatch_fd(u, &s->watch);
+
+        close_nointr_nofail(s->inotify_fd);
+        s->inotify_fd = -1;
+}
+
+int path_spec_fd_event(PathSpec *s, uint32_t events) {
+        uint8_t *buf = NULL;
+        struct inotify_event *e;
+        ssize_t k;
+        int l;
+        int r = 0;
+
+        if (events != EPOLLIN) {
+                log_error("Got Invalid poll event on inotify.");
+                r = -EINVAL;
+                goto out;
+        }
+
+        if (ioctl(s->inotify_fd, FIONREAD, &l) < 0) {
+                log_error("FIONREAD failed: %m");
+                r = -errno;
+                goto out;
+        }
+
+        assert(l > 0);
+
+        if (!(buf = malloc(l))) {
+                log_error("Failed to allocate buffer: %m");
+                r = -errno;
+                goto out;
+        }
+
+        if ((k = read(s->inotify_fd, buf, l)) < 0) {
+                log_error("Failed to read inotify event: %m");
+                r = -errno;
+                goto out;
+        }
+
+        e = (struct inotify_event*) buf;
+
+        while (k > 0) {
+                size_t step;
+
+                if ((s->type == PATH_CHANGED || s->type == PATH_MODIFIED) &&
+                    s->primary_wd == e->wd)
+                        r = 1;
+
+                step = sizeof(struct inotify_event) + e->len;
+                assert(step <= (size_t) k);
+
+                e = (struct inotify_event*) ((uint8_t*) e + step);
+                k -= step;
+        }
+out:
+        free(buf);
+        return r;
+}
+
+static bool path_spec_check_good(PathSpec *s, bool initial) {
+        bool good = false;
+
+        switch (s->type) {
+
+        case PATH_EXISTS:
+                good = access(s->path, F_OK) >= 0;
+                break;
+
+        case PATH_EXISTS_GLOB:
+                good = glob_exists(s->path) > 0;
+                break;
+
+        case PATH_DIRECTORY_NOT_EMPTY: {
+                int k;
+
+                k = dir_is_empty(s->path);
+                good = !(k == -ENOENT || k > 0);
+                break;
+        }
+
+        case PATH_CHANGED:
+        case PATH_MODIFIED: {
+                bool b;
+
+                b = access(s->path, F_OK) >= 0;
+                good = !initial && b != s->previous_exists;
+                s->previous_exists = b;
+                break;
+        }
+
+        default:
+                ;
+        }
+
+        return good;
+}
+
+static bool path_spec_startswith(PathSpec *s, const char *what) {
+        return path_startswith(s->path, what);
+}
+
+static void path_spec_mkdir(PathSpec *s, mode_t mode) {
+        int r;
+
+        if (s->type == PATH_EXISTS || s->type == PATH_EXISTS_GLOB)
+                return;
+
+        if ((r = mkdir_p_label(s->path, mode)) < 0)
+                log_warning("mkdir(%s) failed: %s", s->path, strerror(-r));
+}
+
+static void path_spec_dump(PathSpec *s, FILE *f, const char *prefix) {
+        fprintf(f,
+                "%s%s: %s\n",
+                prefix,
+                path_type_to_string(s->type),
+                s->path);
+}
+
+void path_spec_done(PathSpec *s) {
+        assert(s);
+        assert(s->inotify_fd == -1);
+
+        free(s->path);
+}
+
+static void path_init(Unit *u) {
+        Path *p = PATH(u);
+
+        assert(u);
+        assert(u->load_state == UNIT_STUB);
+
+        p->directory_mode = 0755;
+}
+
+static void path_done(Unit *u) {
+        Path *p = PATH(u);
+        PathSpec *s;
+
+        assert(p);
+
+        unit_ref_unset(&p->unit);
+
+        while ((s = p->specs)) {
+                path_spec_unwatch(s, u);
+                LIST_REMOVE(PathSpec, spec, p->specs, s);
+                path_spec_done(s);
+                free(s);
+        }
+}
+
+int path_add_one_mount_link(Path *p, Mount *m) {
+        PathSpec *s;
+        int r;
+
+        assert(p);
+        assert(m);
+
+        if (UNIT(p)->load_state != UNIT_LOADED ||
+            UNIT(m)->load_state != UNIT_LOADED)
+                return 0;
+
+        LIST_FOREACH(spec, s, p->specs) {
+
+                if (!path_spec_startswith(s, m->where))
+                        continue;
+
+                if ((r = unit_add_two_dependencies(UNIT(p), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+static int path_add_mount_links(Path *p) {
+        Unit *other;
+        int r;
+
+        assert(p);
+
+        LIST_FOREACH(units_by_type, other, UNIT(p)->manager->units_by_type[UNIT_MOUNT])
+                if ((r = path_add_one_mount_link(p, MOUNT(other))) < 0)
+                        return r;
+
+        return 0;
+}
+
+static int path_verify(Path *p) {
+        assert(p);
+
+        if (UNIT(p)->load_state != UNIT_LOADED)
+                return 0;
+
+        if (!p->specs) {
+                log_error("%s lacks path setting. Refusing.", UNIT(p)->id);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int path_add_default_dependencies(Path *p) {
+        int r;
+
+        assert(p);
+
+        if (UNIT(p)->manager->running_as == SYSTEMD_SYSTEM) {
+                if ((r = unit_add_dependency_by_name(UNIT(p), UNIT_BEFORE, SPECIAL_BASIC_TARGET, NULL, true)) < 0)
+                        return r;
+
+                if ((r = unit_add_two_dependencies_by_name(UNIT(p), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true)) < 0)
+                        return r;
+        }
+
+        return unit_add_two_dependencies_by_name(UNIT(p), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
+}
+
+static int path_load(Unit *u) {
+        Path *p = PATH(u);
+        int r;
+
+        assert(u);
+        assert(u->load_state == UNIT_STUB);
+
+        if ((r = unit_load_fragment_and_dropin(u)) < 0)
+                return r;
+
+        if (u->load_state == UNIT_LOADED) {
+
+                if (!UNIT_DEREF(p->unit)) {
+                        Unit *x;
+
+                        r = unit_load_related_unit(u, ".service", &x);
+                        if (r < 0)
+                                return r;
+
+                        unit_ref_set(&p->unit, x);
+                }
+
+                r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, UNIT_DEREF(p->unit), true);
+                if (r < 0)
+                        return r;
+
+                if ((r = path_add_mount_links(p)) < 0)
+                        return r;
+
+                if (UNIT(p)->default_dependencies)
+                        if ((r = path_add_default_dependencies(p)) < 0)
+                                return r;
+        }
+
+        return path_verify(p);
+}
+
+static void path_dump(Unit *u, FILE *f, const char *prefix) {
+        Path *p = PATH(u);
+        PathSpec *s;
+
+        assert(p);
+        assert(f);
+
+        fprintf(f,
+                "%sPath State: %s\n"
+                "%sResult: %s\n"
+                "%sUnit: %s\n"
+                "%sMakeDirectory: %s\n"
+                "%sDirectoryMode: %04o\n",
+                prefix, path_state_to_string(p->state),
+                prefix, path_result_to_string(p->result),
+                prefix, UNIT_DEREF(p->unit)->id,
+                prefix, yes_no(p->make_directory),
+                prefix, p->directory_mode);
+
+        LIST_FOREACH(spec, s, p->specs)
+                path_spec_dump(s, f, prefix);
+}
+
+static void path_unwatch(Path *p) {
+        PathSpec *s;
+
+        assert(p);
+
+        LIST_FOREACH(spec, s, p->specs)
+                path_spec_unwatch(s, UNIT(p));
+}
+
+static int path_watch(Path *p) {
+        int r;
+        PathSpec *s;
+
+        assert(p);
+
+        LIST_FOREACH(spec, s, p->specs)
+                if ((r = path_spec_watch(s, UNIT(p))) < 0)
+                        return r;
+
+        return 0;
+}
+
+static void path_set_state(Path *p, PathState state) {
+        PathState old_state;
+        assert(p);
+
+        old_state = p->state;
+        p->state = state;
+
+        if (state != PATH_WAITING &&
+            (state != PATH_RUNNING || p->inotify_triggered))
+                path_unwatch(p);
+
+        if (state != old_state)
+                log_debug("%s changed %s -> %s",
+                          UNIT(p)->id,
+                          path_state_to_string(old_state),
+                          path_state_to_string(state));
+
+        unit_notify(UNIT(p), state_translation_table[old_state], state_translation_table[state], true);
+}
+
+static void path_enter_waiting(Path *p, bool initial, bool recheck);
+
+static int path_coldplug(Unit *u) {
+        Path *p = PATH(u);
+
+        assert(p);
+        assert(p->state == PATH_DEAD);
+
+        if (p->deserialized_state != p->state) {
+
+                if (p->deserialized_state == PATH_WAITING ||
+                    p->deserialized_state == PATH_RUNNING)
+                        path_enter_waiting(p, true, true);
+                else
+                        path_set_state(p, p->deserialized_state);
+        }
+
+        return 0;
+}
+
+static void path_enter_dead(Path *p, PathResult f) {
+        assert(p);
+
+        if (f != PATH_SUCCESS)
+                p->result = f;
+
+        path_set_state(p, p->result != PATH_SUCCESS ? PATH_FAILED : PATH_DEAD);
+}
+
+static void path_enter_running(Path *p) {
+        int r;
+        DBusError error;
+
+        assert(p);
+        dbus_error_init(&error);
+
+        /* Don't start job if we are supposed to go down */
+        if (UNIT(p)->job && UNIT(p)->job->type == JOB_STOP)
+                return;
+
+        if ((r = manager_add_job(UNIT(p)->manager, JOB_START, UNIT_DEREF(p->unit), JOB_REPLACE, true, &error, NULL)) < 0)
+                goto fail;
+
+        p->inotify_triggered = false;
+
+        if ((r = path_watch(p)) < 0)
+                goto fail;
+
+        path_set_state(p, PATH_RUNNING);
+        return;
+
+fail:
+        log_warning("%s failed to queue unit startup job: %s", UNIT(p)->id, bus_error(&error, r));
+        path_enter_dead(p, PATH_FAILURE_RESOURCES);
+
+        dbus_error_free(&error);
+}
+
+static bool path_check_good(Path *p, bool initial) {
+        PathSpec *s;
+        bool good = false;
+
+        assert(p);
+
+        LIST_FOREACH(spec, s, p->specs) {
+                good = path_spec_check_good(s, initial);
+
+                if (good)
+                        break;
+        }
+
+        return good;
+}
+
+static void path_enter_waiting(Path *p, bool initial, bool recheck) {
+        int r;
+
+        if (recheck)
+                if (path_check_good(p, initial)) {
+                        log_debug("%s got triggered.", UNIT(p)->id);
+                        path_enter_running(p);
+                        return;
+                }
+
+        if ((r = path_watch(p)) < 0)
+                goto fail;
+
+        /* Hmm, so now we have created inotify watches, but the file
+         * might have appeared/been removed by now, so we must
+         * recheck */
+
+        if (recheck)
+                if (path_check_good(p, false)) {
+                        log_debug("%s got triggered.", UNIT(p)->id);
+                        path_enter_running(p);
+                        return;
+                }
+
+        path_set_state(p, PATH_WAITING);
+        return;
+
+fail:
+        log_warning("%s failed to enter waiting state: %s", UNIT(p)->id, strerror(-r));
+        path_enter_dead(p, PATH_FAILURE_RESOURCES);
+}
+
+static void path_mkdir(Path *p) {
+        PathSpec *s;
+
+        assert(p);
+
+        if (!p->make_directory)
+                return;
+
+        LIST_FOREACH(spec, s, p->specs)
+                path_spec_mkdir(s, p->directory_mode);
+}
+
+static int path_start(Unit *u) {
+        Path *p = PATH(u);
+
+        assert(p);
+        assert(p->state == PATH_DEAD || p->state == PATH_FAILED);
+
+        if (UNIT_DEREF(p->unit)->load_state != UNIT_LOADED)
+                return -ENOENT;
+
+        path_mkdir(p);
+
+        p->result = PATH_SUCCESS;
+        path_enter_waiting(p, true, true);
+
+        return 0;
+}
+
+static int path_stop(Unit *u) {
+        Path *p = PATH(u);
+
+        assert(p);
+        assert(p->state == PATH_WAITING || p->state == PATH_RUNNING);
+
+        path_enter_dead(p, PATH_SUCCESS);
+        return 0;
+}
+
+static int path_serialize(Unit *u, FILE *f, FDSet *fds) {
+        Path *p = PATH(u);
+
+        assert(u);
+        assert(f);
+        assert(fds);
+
+        unit_serialize_item(u, f, "state", path_state_to_string(p->state));
+        unit_serialize_item(u, f, "result", path_result_to_string(p->result));
+
+        return 0;
+}
+
+static int path_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
+        Path *p = PATH(u);
+
+        assert(u);
+        assert(key);
+        assert(value);
+        assert(fds);
+
+        if (streq(key, "state")) {
+                PathState state;
+
+                if ((state = path_state_from_string(value)) < 0)
+                        log_debug("Failed to parse state value %s", value);
+                else
+                        p->deserialized_state = state;
+
+        } else if (streq(key, "result")) {
+                PathResult f;
+
+                f = path_result_from_string(value);
+                if (f < 0)
+                        log_debug("Failed to parse result value %s", value);
+                else if (f != PATH_SUCCESS)
+                        p->result = f;
+
+        } else
+                log_debug("Unknown serialization key '%s'", key);
+
+        return 0;
+}
+
+static UnitActiveState path_active_state(Unit *u) {
+        assert(u);
+
+        return state_translation_table[PATH(u)->state];
+}
+
+static const char *path_sub_state_to_string(Unit *u) {
+        assert(u);
+
+        return path_state_to_string(PATH(u)->state);
+}
+
+static void path_fd_event(Unit *u, int fd, uint32_t events, Watch *w) {
+        Path *p = PATH(u);
+        PathSpec *s;
+        int changed;
+
+        assert(p);
+        assert(fd >= 0);
+
+        if (p->state != PATH_WAITING &&
+            p->state != PATH_RUNNING)
+                return;
+
+        /* log_debug("inotify wakeup on %s.", u->id); */
+
+        LIST_FOREACH(spec, s, p->specs)
+                if (path_spec_owns_inotify_fd(s, fd))
+                        break;
+
+        if (!s) {
+                log_error("Got event on unknown fd.");
+                goto fail;
+        }
+
+        changed = path_spec_fd_event(s, events);
+        if (changed < 0)
+                goto fail;
+
+        /* If we are already running, then remember that one event was
+         * dispatched so that we restart the service only if something
+         * actually changed on disk */
+        p->inotify_triggered = true;
+
+        if (changed)
+                path_enter_running(p);
+        else
+                path_enter_waiting(p, false, true);
+
+        return;
+
+fail:
+        path_enter_dead(p, PATH_FAILURE_RESOURCES);
+}
+
+void path_unit_notify(Unit *u, UnitActiveState new_state) {
+        Iterator i;
+        Unit *k;
+
+        if (u->type == UNIT_PATH)
+                return;
+
+        SET_FOREACH(k, u->dependencies[UNIT_TRIGGERED_BY], i) {
+                Path *p;
+
+                if (k->type != UNIT_PATH)
+                        continue;
+
+                if (k->load_state != UNIT_LOADED)
+                        continue;
+
+                p = PATH(k);
+
+                if (p->state == PATH_RUNNING && new_state == UNIT_INACTIVE) {
+                        log_debug("%s got notified about unit deactivation.", UNIT(p)->id);
+
+                        /* Hmm, so inotify was triggered since the
+                         * last activation, so I guess we need to
+                         * recheck what is going on. */
+                        path_enter_waiting(p, false, p->inotify_triggered);
+                }
+        }
+}
+
+static void path_reset_failed(Unit *u) {
+        Path *p = PATH(u);
+
+        assert(p);
+
+        if (p->state == PATH_FAILED)
+                path_set_state(p, PATH_DEAD);
+
+        p->result = PATH_SUCCESS;
+}
+
+static const char* const path_state_table[_PATH_STATE_MAX] = {
+        [PATH_DEAD] = "dead",
+        [PATH_WAITING] = "waiting",
+        [PATH_RUNNING] = "running",
+        [PATH_FAILED] = "failed"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(path_state, PathState);
+
+static const char* const path_type_table[_PATH_TYPE_MAX] = {
+        [PATH_EXISTS] = "PathExists",
+        [PATH_EXISTS_GLOB] = "PathExistsGlob",
+        [PATH_CHANGED] = "PathChanged",
+        [PATH_MODIFIED] = "PathModified",
+        [PATH_DIRECTORY_NOT_EMPTY] = "DirectoryNotEmpty"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(path_type, PathType);
+
+static const char* const path_result_table[_PATH_RESULT_MAX] = {
+        [PATH_SUCCESS] = "success",
+        [PATH_FAILURE_RESOURCES] = "resources"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(path_result, PathResult);
+
+const UnitVTable path_vtable = {
+        .object_size = sizeof(Path),
+        .sections =
+                "Unit\0"
+                "Path\0"
+                "Install\0",
+
+        .init = path_init,
+        .done = path_done,
+        .load = path_load,
+
+        .coldplug = path_coldplug,
+
+        .dump = path_dump,
+
+        .start = path_start,
+        .stop = path_stop,
+
+        .serialize = path_serialize,
+        .deserialize_item = path_deserialize_item,
+
+        .active_state = path_active_state,
+        .sub_state_to_string = path_sub_state_to_string,
+
+        .fd_event = path_fd_event,
+
+        .reset_failed = path_reset_failed,
+
+        .bus_interface = "org.freedesktop.systemd1.Path",
+        .bus_message_handler = bus_path_message_handler,
+        .bus_invalidating_properties = bus_path_invalidating_properties
+};