journal: fix error handling when compressing journal objectssubmit/tizen_3.0/20170102.034134submit/tizen_3.0.m2/20170104.093755accepted/tizen/3.0/wearable/20170102.095117accepted/tizen/3.0/tv/20170102.095103accepted/tizen/3.0/mobile/20170102.095040accepted/tizen/3.0/ivi/20170102.095140accepted/tizen/3.0/common/20170102.143352accepted/tizen/3.0.m2/wearable/20170105.025732accepted/tizen/3.0.m2/tv/20170105.025646accepted/tizen/3.0.m2/mobile/20170105.025437tizen_3.0.m2accepted/tizen_3.0.m2_wearableaccepted/tizen_3.0.m2_tvaccepted/tizen_3.0.m2_mobile

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.

Conflicts:
	src/journal/journal-file.c
	src/journal/journal-file.h

Change-Id: Ib447838f94b837d6026b07991cb83ad3c4ca6310

2 files changed, 12 insertions, 6 deletions

diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
index 0f28718b0e..1d60b1b0ab 100644
--- a/src/journal/journal-file.c
+++ b/src/journal/journal-file.c
@@ -1051,23 +1051,24 @@ 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) {
-                size_t rsize;
+        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 2526e14d65..7fc8bef49f 100644
--- a/src/journal/journal-file.h
+++ b/src/journal/journal-file.h
@@ -229,3 +229,8 @@ int journal_file_get_cutoff_realtime_usec(JournalFile *f, usec_t *from, usec_t *
 int journal_file_get_cutoff_monotonic_usec(JournalFile *f, sd_id128_t boot, usec_t *from, usec_t *to);
 
 bool journal_file_rotate_suggested(JournalFile *f, usec_t max_file_usec);
+
+static inline bool JOURNAL_FILE_COMPRESS(JournalFile *f) {
+        assert(f);
+        return f->compress_xz || f->compress_lz4;
+}