journal: completely rework the mmap cache as I too dumb to actually understand it

Instead of doing hand optimized fd bisect arrays just use plain old
hashmaps. Now I can understand my own code again. Yay!

As a side effect this should fix some bad memory accesses caused by
accesses after mmap(), introduced in 189.

Makefile.am

@@ -2473,6 +2473,13 @@ test_journal_verify_LDADD = \
 	libsystemd-journal-internal.la \
 	libsystemd-id128-internal.la
 
+test_mmap_cache_SOURCES = \
+	src/journal/test-mmap-cache.c
+
+test_mmap_cache_LDADD = \
+	libsystemd-shared.la \
+	libsystemd-journal-internal.la
+
 libsystemd_journal_la_SOURCES = \
 	src/journal/sd-journal.c \
 	src/systemd/sd-journal.h \
@@ -2577,13 +2584,15 @@ noinst_PROGRAMS += \
 	test-journal-send \
 	test-journal-match \
 	test-journal-stream \
-	test-journal-verify
+	test-journal-verify \
+	test-mmap-cache
 
 TESTS += \
 	test-journal \
 	test-journal-match \
 	test-journal-stream \
-	test-journal-verify
+	test-journal-verify \
+	test-mmap-cache
 
 pkginclude_HEADERS += \
 	src/systemd/sd-journal.h \

TODO

@@ -19,6 +19,11 @@ F18:
 
 Features:
 
+* document that deps in [Unit] sections ignore Alias= fileds in
+  [Install] units of other units, unless those units are disabled
+
+* need to update LGPL2.1 text to newest version (with updated FSF address)
+
 * allow users from "wheel" to start/stop services
 
 * systemctl: when powering down/suspending check for inhibitors, and warn.

src/core/service.c

@@ -1829,7 +1829,6 @@ static int service_spawn(
         if (r < 0)
                 goto fail;
 
-
         if ((r = unit_watch_pid(UNIT(s), pid)) < 0)
                 /* FIXME: we need to do something here */
                 goto fail;

src/journal/mmap-cache.h

@@ -22,6 +22,8 @@
 ***/
 
 #include <inttypes.h>
+#include <stdbool.h>
+#include <sys/stat.h>
 
 typedef struct MMapCache MMapCache;