journalctl: clean up how we log errors

All functions should either log the errors they run into, or only return
them in which case the caller should log them.

Make sure this rule is followed, so that each error is logged precisely
once, and neither never, nor more than once.

1 files changed, 29 insertions, 30 deletions

diff --git a/src/journal/journalctl.c b/src/journal/journalctl.c
index c9a259add0..bbc42583c9 100644
--- a/src/journal/journalctl.c
+++ b/src/journal/journalctl.c
@@ -818,17 +818,11 @@ static int add_matches(sd_journal *j, char **args) {
                                         }
                                 } else
                                         t = strappend("_EXE=", path);
-                        } else if (S_ISCHR(st.st_mode)) {
-                                if (asprintf(&t, "_KERNEL_DEVICE=c%u:%u",
-                                             major(st.st_rdev),
-                                             minor(st.st_rdev)) < 0)
-                                        return -ENOMEM;
-                        } else if (S_ISBLK(st.st_mode)) {
-                                if (asprintf(&t, "_KERNEL_DEVICE=b%u:%u",
-                                             major(st.st_rdev),
-                                             minor(st.st_rdev)) < 0)
-                                        return -ENOMEM;
-                        } else {
+                        } else if (S_ISCHR(st.st_mode))
+                                (void) asprintf(&t, "_KERNEL_DEVICE=c%u:%u", major(st.st_rdev), minor(st.st_rdev));
+                        else if (S_ISBLK(st.st_mode))
+                                (void) asprintf(&t, "_KERNEL_DEVICE=b%u:%u", major(st.st_rdev), minor(st.st_rdev));
+                        else {
                                 log_error("File is neither a device node, nor regular file, nor executable: %s", *i);
                                 return -EINVAL;
                         }
@@ -893,7 +887,7 @@ static int discover_next_boot(
 
         next_boot = new0(BootId, 1);
         if (!next_boot)
-                return log_oom();
+                return -ENOMEM;
 
         r = sd_journal_get_monotonic_usec(j, NULL, &next_boot->id);
         if (r < 0)
@@ -1049,7 +1043,9 @@ static int list_boots(sd_journal *j) {
         assert(j);
 
         count = get_boots(j, &all_ids, NULL, 0);
-        if (count <= 0)
+        if (count < 0)
+                return log_error_errno(count, "Failed to determine boots: %m");
+        if (count == 0)
                 return count;
 
         pager_open_if_enabled();
@@ -1109,7 +1105,7 @@ static int add_boot(sd_journal *j) {
 
         r = sd_journal_add_conjunction(j);
         if (r < 0)
-                return r;
+                return log_error_errno(r, "Failed to add conjunction: %m");
 
         return 0;
 }
@@ -1127,22 +1123,24 @@ static int add_dmesg(sd_journal *j) {
 
         r = sd_journal_add_conjunction(j);
         if (r < 0)
-                return r;
+                return log_error_errno(r, "Failed to add conjunction: %m");
 
         return 0;
 }
 
-static int get_possible_units(sd_journal *j,
-                              const char *fields,
-                              char **patterns,
-                              Set **units) {
+static int get_possible_units(
+                sd_journal *j,
+                const char *fields,
+                char **patterns,
+                Set **units) {
+
         _cleanup_set_free_free_ Set *found;
         const char *field;
         int r;
 
         found = set_new(&string_hash_ops);
         if (!found)
-                return log_oom();
+                return -ENOMEM;
 
         NULSTR_FOREACH(field, fields) {
                 const void *data;
@@ -1165,7 +1163,7 @@ static int get_possible_units(sd_journal *j,
 
                         u = strndup((char*) data + prefix, size - prefix);
                         if (!u)
-                                return log_oom();
+                                return -ENOMEM;
 
                         STRV_FOREACH(pattern, patterns)
                                 if (fnmatch(*pattern, u, FNM_NOESCAPE) == 0) {
@@ -1329,7 +1327,7 @@ static int add_priorities(sd_journal *j) {
 
         r = sd_journal_add_conjunction(j);
         if (r < 0)
-                return r;
+                return log_error_errno(r, "Failed to add conjunction: %m");
 
         return 0;
 }
@@ -1930,21 +1928,20 @@ int main(int argc, char *argv[]) {
         }
 
         r = add_priorities(j);
-        if (r < 0) {
-                log_error_errno(r, "Failed to add filter for priorities: %m");
+        if (r < 0)
                 goto finish;
-        }
 
         r = add_matches(j, argv + optind);
-        if (r < 0) {
-                log_error_errno(r, "Failed to add filters: %m");
+        if (r < 0)
                 goto finish;
-        }
 
         if (_unlikely_(log_get_max_level() >= LOG_DEBUG)) {
                 _cleanup_free_ char *filter;
 
                 filter = journal_make_match_string(j);
+                if (!filter)
+                        return log_oom();
+
                 log_debug("Journal filter: %s", filter);
         }
 
@@ -1954,7 +1951,7 @@ int main(int argc, char *argv[]) {
 
                 r = sd_journal_set_data_threshold(j, 0);
                 if (r < 0) {
-                        log_error("Failed to unset data size threshold");
+                        log_error_errno(r, "Failed to unset data size threshold: %m");
                         goto finish;
                 }
 
@@ -1986,8 +1983,10 @@ int main(int argc, char *argv[]) {
         /* Opening the fd now means the first sd_journal_wait() will actually wait */
         if (arg_follow) {
                 r = sd_journal_get_fd(j);
-                if (r < 0)
+                if (r < 0) {
+                        log_error_errno(r, "Failed to get journal fd: %m");
                         goto finish;
+                }
         }
 
         if (arg_cursor || arg_after_cursor) {