journal,shared: add _cleanup_journal_close_

src/shared/logs-show.c

@@ -941,7 +941,7 @@ int show_journal_by_unit(
                 OutputFlags flags,
                 bool system) {
 
-        sd_journal *j = NULL;
+        sd_journal _cleanup_journal_close_ *j = NULL;
         int r;
         int jflags = SD_JOURNAL_LOCAL_ONLY | system * SD_JOURNAL_SYSTEM_ONLY;
 
@@ -954,24 +954,20 @@ int show_journal_by_unit(
 
         r = sd_journal_open(&j, jflags);
         if (r < 0)
-                goto finish;
+                return r;
 
         if (system)
                 r = add_matches_for_unit(j, unit);
         else
                 r = add_matches_for_user_unit(j, unit, uid);
         if (r < 0)
-                goto finish;
+                return r;
 
         r = show_journal(f, j, mode, n_columns, not_before, how_many, flags);
         if (r < 0)
-                goto finish;
+                return r;
 
-finish:
-        if (j)
-                sd_journal_close(j);
-
-        return r;
+        return 0;
 }
 
 static const char *const output_mode_table[_OUTPUT_MODE_MAX] = {

src/shared/macro.h

@@ -203,6 +203,7 @@ static inline size_t IOVEC_INCREMENT(struct iovec *i, unsigned n, size_t k) {
 #define _cleanup_set_free_ __attribute__((cleanup(set_freep)))
 #define _cleanup_set_free_free_ __attribute__((cleanup(set_free_freep)))
 #define _cleanup_strv_free_ __attribute__((cleanup(strv_freep)))
+#define _cleanup_journal_close_ __attribute__((cleanup(journal_closep)))
 
 #define VA_FORMAT_ADVANCE(format, ap)                                   \
 do {                                                                    \

src/shared/util.h

@@ -36,6 +36,7 @@
 #include <dirent.h>
 #include <sys/resource.h>
 #include <stddef.h>
+#include <systemd/sd-journal.h>
 
 #include "macro.h"
 #include "time-util.h"
@@ -531,6 +532,10 @@ static inline void umaskp(mode_t *u) {
         umask(*u);
 }
 
+static inline void journal_closep(sd_journal **j) {
+        sd_journal_close(*j);
+}
+
 _malloc_  static inline void *malloc_multiply(size_t a, size_t b) {
         if (_unlikely_(b == 0 || a > ((size_t) -1) / b))
                 return NULL;