journal: fix error handling when compressing journal objects

Let's make sure we handle compression errors properly, and don't
misunderstand an error for success.

Also, let's actually compress things if lz4 is enabled.

Fixes #1662.

diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
index 1071c6d6d73dfa34df64f026266b82ba08b53f1b..89068f26d23cc9ac8f528b0a8b44ec4b8ac8dc5e 100644 (file)
--- a/src/journal/journal-file.c
+++ b/src/journal/journal-file.c
@@ -1076,23 +1076,24 @@ static int journal_file_append_data(
         o->data.hash = htole64(hash);
 
 #if defined(HAVE_XZ) || defined(HAVE_LZ4)
-        if (f->compress_xz &&
-            size >= COMPRESSION_SIZE_THRESHOLD) {
+        if (JOURNAL_FILE_COMPRESS(f) && size >= COMPRESSION_SIZE_THRESHOLD) {
                 size_t rsize = 0;
 
                 compression = compress_blob(data, size, o->data.payload, &rsize);
 
-                if (compression) {
+                if (compression >= 0) {
                         o->object.size = htole64(offsetof(Object, data.payload) + rsize);
                         o->object.flags |= compression;
 
                         log_debug("Compressed data object %"PRIu64" -> %zu using %s",
                                   size, rsize, object_compressed_to_string(compression));
-                }
+                } else
+                        /* Compression didn't work, we don't really care why, let's continue without compression */
+                        compression = 0;
         }
 #endif
 
-        if (!compression && size > 0)
+        if (compression == 0 && size > 0)
                 memcpy(o->data.payload, data, size);
 
         r = journal_file_link_data(f, o, p, hash);

diff --git a/src/journal/journal-file.h b/src/journal/journal-file.h
index f2c07356c82c543e2d21fdb8c5d24edb5e461c36..898d12d9924d331a0f70b4c5eebbb9d17727252f 100644 (file)
--- a/src/journal/journal-file.h
+++ b/src/journal/journal-file.h
@@ -235,3 +235,8 @@ bool journal_file_rotate_suggested(JournalFile *f, usec_t max_file_usec);
 
 int journal_file_map_data_hash_table(JournalFile *f);
 int journal_file_map_field_hash_table(JournalFile *f);
+
+static inline bool JOURNAL_FILE_COMPRESS(JournalFile *f) {
+        assert(f);
+        return f->compress_xz || f->compress_lz4;
+}