sd-journal: properly handle inotify queue overflow

This adds proper handling of IN_Q_OVERFLOW: when the inotify queue runs
over we'll reiterate all directories we are looking at. At the same time
we'll mark all files and directories we encounter that way with a
generation counter we first increased. All files and directories not
marked like this are then unloaded.

With this logic we do the best when the inotify queue overflows: we
synchronize our in-memory state again with what's on disk.

This contains some refactoring of the directory logic, to share more
code between uuid directories and "root" directories and generally make
things a bit more readable by splitting things up into smaller bits.

See: #7998 #8032

1 files changed, 2 insertions, 0 deletions

diff --git a/src/journal/journal-internal.h b/src/journal/journal-internal.h
index d0d2842cc4..e5f563cced 100644
--- a/src/journal/journal-internal.h
+++ b/src/journal/journal-internal.h
@@ -80,6 +80,7 @@ struct Directory {
         char *path;
         int wd;
         bool is_root;
+        unsigned last_seen_generation;
 };
 
 struct sd_journal {
@@ -104,6 +105,7 @@ struct sd_journal {
         int inotify_fd;
         unsigned current_invalidate_counter, last_invalidate_counter;
         usec_t last_process_usec;
+        unsigned generation;
 
         /* Iterating through unique fields and their data values */
         char *unique_field;