path: refactor PathSpec usage

path_*() functions operate on "Path *p" and they do not touch PathSpec
internals directly.

pathspec_*() functions operate on "PathSpec *s". The PathSpec class will
be useful outside of path.c.

2 files changed, 203 insertions, 161 deletions

diff --git a/src/path.c b/src/path.c
index 142fd2d8ac..db6f873dca 100644
--- a/src/path.c
+++ b/src/path.c
@@ -39,26 +39,202 @@ static const UnitActiveState state_translation_table[_PATH_STATE_MAX] = {
         [PATH_FAILED] = UNIT_FAILED
 };
 
-static void path_init(Unit *u) {
-        Path *p = PATH(u);
+int pathspec_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_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(u->meta.load_state == UNIT_STUB);
+        assert(s);
 
-        p->directory_mode = 0755;
+        pathspec_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;
+        }
+
+        if ((s->primary_wd = inotify_add_watch(s->inotify_fd, k, flags_table[s->type])) >= 0)
+                exists = true;
+
+        do {
+                int flags;
+
+                /* This assumes the path was passed through path_kill_slashes()! */
+                if (!(slash = strrchr(k, '/')))
+                        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);
+
+        pathspec_unwatch(s, u);
+        return r;
 }
 
-static void path_unwatch_one(Path *p, PathSpec *s) {
+void pathspec_unwatch(PathSpec *s, Unit *u) {
 
         if (s->inotify_fd < 0)
                 return;
 
-        unit_unwatch_fd(UNIT(p), &s->watch);
+        unit_unwatch_fd(u, &s->watch);
 
         close_nointr_nofail(s->inotify_fd);
         s->inotify_fd = -1;
 }
 
+int pathspec_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->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 pathspec_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: {
+                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 pathspec_startswith(PathSpec *s, const char *what) {
+        return path_startswith(s->path, what);
+}
+
+static void pathspec_mkdir(PathSpec *s, mode_t mode) {
+        int r;
+
+        if (s->type == PATH_EXISTS || s->type == PATH_EXISTS_GLOB)
+                return;
+
+        if ((r = mkdir_p(s->path, mode)) < 0)
+                log_warning("mkdir(%s) failed: %s", s->path, strerror(-r));
+}
+
+static void pathspec_dump(PathSpec *s, FILE *f, const char *prefix) {
+        fprintf(f,
+                "%s%s: %s\n",
+                prefix,
+                path_type_to_string(s->type),
+                s->path);
+}
+
+void pathspec_done(PathSpec *s) {
+        assert(s->inotify_fd == -1);
+        free(s->path);
+}
+
+static void path_init(Unit *u) {
+        Path *p = PATH(u);
+
+        assert(u);
+        assert(u->meta.load_state == UNIT_STUB);
+
+        p->directory_mode = 0755;
+}
+
 static void path_done(Unit *u) {
         Path *p = PATH(u);
         PathSpec *s;
@@ -66,9 +242,9 @@ static void path_done(Unit *u) {
         assert(p);
 
         while ((s = p->specs)) {
-                path_unwatch_one(p, s);
+                pathspec_unwatch(s, u);
                 LIST_REMOVE(PathSpec, spec, p->specs, s);
-                free(s->path);
+                pathspec_done(s);
                 free(s);
         }
 }
@@ -86,7 +262,7 @@ int path_add_one_mount_link(Path *p, Mount *m) {
 
         LIST_FOREACH(spec, s, p->specs) {
 
-                if (!path_startswith(s->path, m->where))
+                if (!pathspec_startswith(s, m->where))
                         continue;
 
                 if ((r = unit_add_two_dependencies(UNIT(p), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
@@ -187,71 +363,7 @@ static void path_dump(Unit *u, FILE *f, const char *prefix) {
                 prefix, p->directory_mode);
 
         LIST_FOREACH(spec, s, p->specs)
-                fprintf(f,
-                        "%s%s: %s\n",
-                        prefix,
-                        path_type_to_string(s->type),
-                        s->path);
-}
-
-static int path_watch_one(Path *p, PathSpec *s) {
-        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_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(p);
-        assert(s);
-
-        path_unwatch_one(p, s);
-
-        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(UNIT(p), s->inotify_fd, EPOLLIN, &s->watch) < 0) {
-                r = -errno;
-                goto fail;
-        }
-
-        if ((s->primary_wd = inotify_add_watch(s->inotify_fd, k, flags_table[s->type])) >= 0)
-                exists = true;
-
-        do {
-                int flags;
-
-                /* This assumes the path was passed through path_kill_slashes()! */
-                if (!(slash = strrchr(k, '/')))
-                        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_unwatch_one(p, s);
-        return r;
+                pathspec_dump(s, f, prefix);
 }
 
 static void path_unwatch(Path *p) {
@@ -260,7 +372,7 @@ static void path_unwatch(Path *p) {
         assert(p);
 
         LIST_FOREACH(spec, s, p->specs)
-                path_unwatch_one(p, s);
+                pathspec_unwatch(s, UNIT(p));
 }
 
 static int path_watch(Path *p) {
@@ -270,7 +382,7 @@ static int path_watch(Path *p) {
         assert(p);
 
         LIST_FOREACH(spec, s, p->specs)
-                if ((r = path_watch_one(p, s)) < 0)
+                if ((r = pathspec_watch(s, UNIT(p))) < 0)
                         return r;
 
         return 0;
@@ -361,37 +473,7 @@ static bool path_check_good(Path *p, bool initial) {
         assert(p);
 
         LIST_FOREACH(spec, s, p->specs) {
-
-                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: {
-                        bool b;
-
-                        b = access(s->path, F_OK) >= 0;
-                        good = !initial && b != s->previous_exists;
-                        s->previous_exists = b;
-                        break;
-                }
-
-                default:
-                        ;
-                }
+                good = pathspec_check_good(s, initial);
 
                 if (good)
                         break;
@@ -440,15 +522,8 @@ static void path_mkdir(Path *p) {
         if (!p->make_directory)
                 return;
 
-        LIST_FOREACH(spec, s, p->specs) {
-                int r;
-
-                if (s->type == PATH_EXISTS || s->type == PATH_EXISTS_GLOB)
-                        continue;
-
-                if ((r = mkdir_p(s->path, p->directory_mode)) < 0)
-                        log_warning("mkdir(%s) failed: %s", s->path, strerror(-r));
-        }
+        LIST_FOREACH(spec, s, p->specs)
+                pathspec_mkdir(s, p->directory_mode);
 }
 
 static int path_start(Unit *u) {
@@ -525,12 +600,8 @@ static const char *path_sub_state_to_string(Unit *u) {
 
 static void path_fd_event(Unit *u, int fd, uint32_t events, Watch *w) {
         Path *p = PATH(u);
-        int l;
-        ssize_t k;
-        uint8_t *buf = NULL;
-        struct inotify_event *e;
         PathSpec *s;
-        bool changed;
+        int changed;
 
         assert(p);
         assert(fd >= 0);
@@ -541,13 +612,8 @@ static void path_fd_event(Unit *u, int fd, uint32_t events, Watch *w) {
 
         /* log_debug("inotify wakeup on %s.", u->meta.id); */
 
-        if (events != EPOLLIN) {
-                log_error("Got Invalid poll event on inotify.");
-                goto fail;
-        }
-
         LIST_FOREACH(spec, s, p->specs)
-                if (s->inotify_fd == fd)
+                if (pathspec_owns_inotify_fd(s, fd))
                         break;
 
         if (!s) {
@@ -555,55 +621,23 @@ static void path_fd_event(Unit *u, int fd, uint32_t events, Watch *w) {
                 goto fail;
         }
 
-        if (ioctl(fd, FIONREAD, &l) < 0) {
-                log_error("FIONREAD failed: %m");
-                goto fail;
-        }
-
-        assert(l > 0);
-
-        if (!(buf = malloc(l))) {
-                log_error("Failed to allocate buffer: %s", strerror(ENOMEM));
-                goto fail;
-        }
-
-        if ((k = read(fd, buf, l)) < 0) {
-                log_error("Failed to read inotify event: %m");
+        changed = pathspec_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;
 
-        e = (struct inotify_event*) buf;
-
-        changed = false;
-        while (k > 0) {
-                size_t step;
-
-                if (s->type == PATH_CHANGED && s->primary_wd == e->wd)
-                        changed = true;
-
-                step = sizeof(struct inotify_event) + e->len;
-                assert(step <= (size_t) k);
-
-                e = (struct inotify_event*) ((uint8_t*) e + step);
-                k -= step;
-        }
-
         if (changed)
                 path_enter_running(p);
         else
                 path_enter_waiting(p, false, true);
 
-        free(buf);
-
         return;
 
 fail:
-        free(buf);
         path_enter_dead(p, false);
 }
 
diff --git a/src/path.h b/src/path.h
index 116fc63ff7..4e6ccf5b0e 100644
--- a/src/path.h
+++ b/src/path.h
@@ -60,6 +60,14 @@ typedef struct PathSpec {
 
 } PathSpec;
 
+int  pathspec_watch(PathSpec *s, Unit *u);
+void pathspec_unwatch(PathSpec *s, Unit *u);
+int  pathspec_fd_event(PathSpec *s, uint32_t events);
+void pathspec_done(PathSpec *s);
+static inline bool pathspec_owns_inotify_fd(PathSpec *s, int fd) {
+        return s->inotify_fd == fd;
+}
+
 struct Path {
         Meta meta;