systemd/SOURCES/0246-sd-journal-always-use-the-compression-algorithm-spec.patch

From 0eb906f1a10a8667ead6f1dc5c308f07c9c2b691 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 4 Apr 2023 18:22:50 +0900
Subject: [PATCH] sd-journal: always use the compression algorithm specified in
 the header

Previously, data object may be compressed with an algorithm that is not
mentioned in the header.

(cherry picked from commit 2360352ef02548723ac0c8eaf5ff6905eb9eeca5)

Resolves: #2183546
---
 src/libsystemd/sd-journal/journal-file.c | 40 ++++++++++++++----------
 src/libsystemd/sd-journal/journal-file.h | 12 +++++--
 2 files changed, 33 insertions(+), 19 deletions(-)

diff --git a/src/libsystemd/sd-journal/journal-file.c b/src/libsystemd/sd-journal/journal-file.c
index 00de564499..1b8f0abf97 100644
--- a/src/libsystemd/sd-journal/journal-file.c
+++ b/src/libsystemd/sd-journal/journal-file.c
@@ -1593,24 +1593,31 @@ static int journal_file_append_field(
 }
 
 static Compression maybe_compress_payload(JournalFile *f, uint8_t *dst, const uint8_t *src, uint64_t size, size_t *rsize) {
-        Compression compression = COMPRESSION_NONE;
-
         assert(f);
         assert(f->header);
 
 #if HAVE_COMPRESSION
-        if (JOURNAL_FILE_COMPRESS(f) && size >= f->compress_threshold_bytes) {
-                compression = compress_blob(src, size, dst, size - 1, rsize);
-                if (compression > 0)
-                        log_debug("Compressed data object %"PRIu64" -> %zu using %s",
-                                  size, *rsize, compression_to_string(compression));
-                else
-                        /* Compression didn't work, we don't really care why, let's continue without compression */
-                        compression = COMPRESSION_NONE;
+        Compression c;
+        int r;
+
+        c = JOURNAL_FILE_COMPRESSION(f);
+        if (c == COMPRESSION_NONE || size < f->compress_threshold_bytes)
+                return COMPRESSION_NONE;
+
+        r = compress_blob_explicit(c, src, size, dst, size - 1, rsize);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to compress data object using %s, ignoring: %m", compression_to_string(c));
+                /* Compression didn't work, we don't really care why, let's continue without compression */
+                return COMPRESSION_NONE;
         }
-#endif
 
-        return compression;
+        assert(r == c);
+        log_debug("Compressed data object %"PRIu64" -> %zu using %s", size, *rsize, compression_to_string(c));
+
+        return c;
+#else
+        return COMPRESSION_NONE;
+#endif
 }
 
 static int journal_file_append_data(
@@ -3887,20 +3894,21 @@ int journal_file_open(
         f->close_fd = true;
 
         if (DEBUG_LOGGING) {
-                static int last_seal = -1, last_compress = -1, last_keyed_hash = -1;
+                static int last_seal = -1, last_keyed_hash = -1;
+                static Compression last_compression = _COMPRESSION_INVALID;
                 static uint64_t last_bytes = UINT64_MAX;
 
                 if (last_seal != JOURNAL_HEADER_SEALED(f->header) ||
                     last_keyed_hash != JOURNAL_HEADER_KEYED_HASH(f->header) ||
-                    last_compress != JOURNAL_FILE_COMPRESS(f) ||
+                    last_compression != JOURNAL_FILE_COMPRESSION(f) ||
                     last_bytes != f->compress_threshold_bytes) {
 
                         log_debug("Journal effective settings seal=%s keyed_hash=%s compress=%s compress_threshold_bytes=%s",
                                   yes_no(JOURNAL_HEADER_SEALED(f->header)), yes_no(JOURNAL_HEADER_KEYED_HASH(f->header)),
-                                  yes_no(JOURNAL_FILE_COMPRESS(f)), FORMAT_BYTES(f->compress_threshold_bytes));
+                                  compression_to_string(JOURNAL_FILE_COMPRESSION(f)), FORMAT_BYTES(f->compress_threshold_bytes));
                         last_seal = JOURNAL_HEADER_SEALED(f->header);
                         last_keyed_hash = JOURNAL_HEADER_KEYED_HASH(f->header);
-                        last_compress = JOURNAL_FILE_COMPRESS(f);
+                        last_compression = JOURNAL_FILE_COMPRESSION(f);
                         last_bytes = f->compress_threshold_bytes;
                 }
         }
diff --git a/src/libsystemd/sd-journal/journal-file.h b/src/libsystemd/sd-journal/journal-file.h
index 1f3c80c912..0321da4a16 100644
--- a/src/libsystemd/sd-journal/journal-file.h
+++ b/src/libsystemd/sd-journal/journal-file.h
@@ -305,10 +305,16 @@ bool journal_file_rotate_suggested(JournalFile *f, usec_t max_file_usec, int log
 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) {
+static inline Compression JOURNAL_FILE_COMPRESSION(JournalFile *f) {
         assert(f);
-        return JOURNAL_HEADER_COMPRESSED_XZ(f->header) || JOURNAL_HEADER_COMPRESSED_LZ4(f->header) ||
-                        JOURNAL_HEADER_COMPRESSED_ZSTD(f->header);
+
+        if (JOURNAL_HEADER_COMPRESSED_XZ(f->header))
+                return COMPRESSION_XZ;
+        if (JOURNAL_HEADER_COMPRESSED_LZ4(f->header))
+                return COMPRESSION_LZ4;
+        if (JOURNAL_HEADER_COMPRESSED_ZSTD(f->header))
+                return COMPRESSION_ZSTD;
+        return COMPRESSION_NONE;
 }
 
 uint64_t journal_file_hash_data(JournalFile *f, const void *data, size_t sz);