teknoraver / rpms / systemd

Forked from rpms/systemd 2 months ago
Clone

Blame 0125-journal-compress-use-LZ4_compress_continue.patch

Zbigniew Jędrzejewski-Szmek 62fe94
From b4232628f3d4b00c967310d56c0e95715c9d05cd Mon Sep 17 00:00:00 2001
Zbigniew Jędrzejewski-Szmek 62fe94
From: Evangelos Foutras <evangelos@foutrelis.com>
Zbigniew Jędrzejewski-Szmek 62fe94
Date: Sat, 30 Aug 2014 10:13:43 +0300
Zbigniew Jędrzejewski-Szmek 62fe94
Subject: [PATCH] journal/compress: use LZ4_compress_continue()
Zbigniew Jędrzejewski-Szmek 62fe94
Zbigniew Jędrzejewski-Szmek 62fe94
We can't use LZ4_compress_limitedOutput_continue() because in the
Zbigniew Jędrzejewski-Szmek 62fe94
worst-case scenario the compressed output can be slightly bigger than
Zbigniew Jędrzejewski-Szmek 62fe94
the input block. This generally affects very few blocks and is no reason
Zbigniew Jędrzejewski-Szmek 62fe94
to abort the compression process.
Zbigniew Jędrzejewski-Szmek 62fe94
Zbigniew Jędrzejewski-Szmek 62fe94
I ran into this when I noticed that Chromium core dumps weren't being
Zbigniew Jędrzejewski-Szmek 62fe94
compressed. After switching to LZ4_compress_continue() a ~330MB Chromium
Zbigniew Jędrzejewski-Szmek 62fe94
core dump gets compressed to ~17M.
Zbigniew Jędrzejewski-Szmek 62fe94
---
Zbigniew Jędrzejewski-Szmek 62fe94
 src/journal/compress.c | 6 +++---
Zbigniew Jędrzejewski-Szmek 62fe94
 1 file changed, 3 insertions(+), 3 deletions(-)
Zbigniew Jędrzejewski-Szmek 62fe94
Zbigniew Jędrzejewski-Szmek 62fe94
diff --git a/src/journal/compress.c b/src/journal/compress.c
Zbigniew Jędrzejewski-Szmek 62fe94
index 52a4c100b3..c4c715be2f 100644
Zbigniew Jędrzejewski-Szmek 62fe94
--- a/src/journal/compress.c
Zbigniew Jędrzejewski-Szmek 62fe94
+++ b/src/journal/compress.c
Zbigniew Jędrzejewski-Szmek 62fe94
@@ -460,10 +460,10 @@ int compress_stream_lz4(int fdf, int fdt, off_t max_bytes) {
Zbigniew Jędrzejewski-Szmek 62fe94
 
Zbigniew Jędrzejewski-Szmek 62fe94
                 total_in += n;
Zbigniew Jędrzejewski-Szmek 62fe94
 
Zbigniew Jędrzejewski-Szmek 62fe94
-                r = LZ4_compress_limitedOutput_continue(&lz4_data, buf, out, n, n);
Zbigniew Jędrzejewski-Szmek 62fe94
+                r = LZ4_compress_continue(&lz4_data, buf, out, n);
Zbigniew Jędrzejewski-Szmek 62fe94
                 if (r == 0) {
Zbigniew Jędrzejewski-Szmek 62fe94
-                        log_debug("Compressed size exceeds original, aborting compression.");
Zbigniew Jędrzejewski-Szmek 62fe94
-                        return -ENOBUFS;
Zbigniew Jędrzejewski-Szmek 62fe94
+                        log_error("LZ4 compression failed.");
Zbigniew Jędrzejewski-Szmek 62fe94
+                        return -EBADMSG;
Zbigniew Jędrzejewski-Szmek 62fe94
                 }
Zbigniew Jędrzejewski-Szmek 62fe94
 
Zbigniew Jędrzejewski-Szmek 62fe94
                 header = htole32(r);