core/path: catch errors when adding watches

Errors because of oom conditions or descriptor exhaustion should not
be ignored. We probably cannot recover from those conditions.

Current behaviour wrt. insufficient permissions is described in the
man page. It might make sense in case of user sessions, so I left
it as is.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/core/path.c b/src/core/path.c
index dcb3b1ff6..fc101280a 100644
--- a/src/core/path.c
+++ b/src/core/path.c
@@ -79,6 +79,11 @@ int path_spec_watch(PathSpec *s, Unit *u) {
         s->primary_wd = inotify_add_watch(s->inotify_fd, k, flags_table[s->type]);
         if (s->primary_wd >= 0)
                 exists = true;
+        else if (errno != EACCES && errno != ENOENT) {
+                log_error("Failed to add watch on %s: %m", k);
+                r = -errno;
+                goto fail;
+        }
 
         do {
                 int flags;
@@ -97,8 +102,20 @@ int path_spec_watch(PathSpec *s, Unit *u) {
 
                 if (inotify_add_watch(s->inotify_fd, k, flags) >= 0)
                         exists = true;
+                else if (errno != EACCES && errno != ENOENT) {
+                        log_error("Failed to add watch on %s: %m", k);
+                        r = -errno;
+                        goto fail;
+                }
         } while (slash != k);
 
+        if (!exists) {
+                log_error("Failed to add watch on any of the components of %s: %m",
+                          s->path);
+                r = -errno;
+                goto fail;
+        }
+
         return 0;
 
 fail: