This patch adds DEFLATE compression algorithm support to erofs-utils
compression framework.

Note that windowbits (which indicates dictionary size) is recorded in
the on-disk compression configuration.  Since some accelerators (e.g.
Intel IAA) don't have enough on-chip memory, compressed data generated
with large windowbits (e.g. > 12 for the IAA accelerator) doesn't seem
to be worked properly on those.

Signed-off-by: Gao Xiang <[email protected]>
---
v2:
  improve print message.

 lib/Makefile.am          |  2 +-
 lib/compress.c           | 24 +++++++++++++
 lib/compressor.c         |  1 +
 lib/compressor.h         |  1 +
 lib/compressor_deflate.c | 78 ++++++++++++++++++++++++++++++++++++++++
 5 files changed, 105 insertions(+), 1 deletion(-)
 create mode 100644 lib/compressor_deflate.c

diff --git a/lib/Makefile.am b/lib/Makefile.am
index fa3b804..553b387 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -44,4 +44,4 @@ liberofs_la_CFLAGS += ${liblzma_CFLAGS}
 liberofs_la_SOURCES += compressor_liblzma.c
 endif
 
-liberofs_la_SOURCES += kite_deflate.c
+liberofs_la_SOURCES += kite_deflate.c compressor_deflate.c
diff --git a/lib/compress.c b/lib/compress.c
index 14d228f..318b8de 100644
--- a/lib/compress.c
+++ b/lib/compress.c
@@ -1026,6 +1026,8 @@ static int erofs_get_compress_algorithm_id(const char 
*name)
                return Z_EROFS_COMPRESSION_LZ4;
        if (!strcmp(name, "lzma"))
                return Z_EROFS_COMPRESSION_LZMA;
+       if (!strcmp(name, "deflate"))
+               return Z_EROFS_COMPRESSION_DEFLATE;
        return -ENOTSUP;
 }
 
@@ -1080,6 +1082,28 @@ int z_erofs_build_compr_cfgs(struct erofs_buffer_head 
*sb_bh)
                bh->op = &erofs_drop_directly_bhops;
        }
 #endif
+       if (sbi.available_compr_algs & (1 << Z_EROFS_COMPRESSION_DEFLATE)) {
+               struct {
+                       __le16 size;
+                       struct z_erofs_deflate_cfgs z;
+               } __packed zalg = {
+                       .size = cpu_to_le16(sizeof(struct 
z_erofs_deflate_cfgs)),
+                       .z = {
+                               .windowbits =
+                                       cpu_to_le32(ilog2(cfg.c_dict_size)),
+                       }
+               };
+
+               bh = erofs_battach(bh, META, sizeof(zalg));
+               if (IS_ERR(bh)) {
+                       DBG_BUGON(1);
+                       return PTR_ERR(bh);
+               }
+               erofs_mapbh(bh->block);
+               ret = dev_write(&zalg, erofs_btell(bh, false),
+                               sizeof(zalg));
+               bh->op = &erofs_drop_directly_bhops;
+       }
        return ret;
 }
 
diff --git a/lib/compressor.c b/lib/compressor.c
index 52eb761..ca4d364 100644
--- a/lib/compressor.c
+++ b/lib/compressor.c
@@ -20,6 +20,7 @@ static const struct erofs_compressor *compressors[] = {
 #if HAVE_LIBLZMA
                &erofs_compressor_lzma,
 #endif
+               &erofs_compressor_deflate,
 };
 
 int erofs_compress_destsize(const struct erofs_compress *c,
diff --git a/lib/compressor.h b/lib/compressor.h
index cf063f1..c1eee20 100644
--- a/lib/compressor.h
+++ b/lib/compressor.h
@@ -44,6 +44,7 @@ struct erofs_compress {
 extern const struct erofs_compressor erofs_compressor_lz4;
 extern const struct erofs_compressor erofs_compressor_lz4hc;
 extern const struct erofs_compressor erofs_compressor_lzma;
+extern const struct erofs_compressor erofs_compressor_deflate;
 
 int erofs_compress_destsize(const struct erofs_compress *c,
                            const void *src, unsigned int *srcsize,
diff --git a/lib/compressor_deflate.c b/lib/compressor_deflate.c
new file mode 100644
index 0000000..5a7a657
--- /dev/null
+++ b/lib/compressor_deflate.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0+ OR Apache-2.0
+/*
+ * Copyright (C) 2023, Alibaba Cloud
+ * Copyright (C) 2023, Gao Xiang <[email protected]>
+ */
+#include "erofs/internal.h"
+#include "erofs/print.h"
+#include "erofs/config.h"
+#include "compressor.h"
+
+void *kite_deflate_init(int level, unsigned int dict_size);
+void kite_deflate_end(void *s);
+int kite_deflate_destsize(void *s, const u8 *in, u8 *out,
+                         unsigned int *srcsize, unsigned int target_dstsize);
+
+static int deflate_compress_destsize(const struct erofs_compress *c,
+                                    const void *src, unsigned int *srcsize,
+                                    void *dst, unsigned int dstsize)
+{
+       int rc = kite_deflate_destsize(c->private_data, src, dst,
+                                      srcsize, dstsize);
+
+       if (rc <= 0)
+               return -EFAULT;
+       return rc;
+}
+
+static int compressor_deflate_exit(struct erofs_compress *c)
+{
+       if (!c->private_data)
+               return -EINVAL;
+
+       kite_deflate_end(c->private_data);
+       return 0;
+}
+
+static int compressor_deflate_init(struct erofs_compress *c)
+{
+       c->alg = &erofs_compressor_deflate;
+       c->private_data = NULL;
+
+       erofs_warn("EXPERIMENTAL DEFLATE algorithm in use. Use at your own 
risk!");
+       erofs_warn("*Carefully* check filesystem data correctness to avoid 
corruption!");
+       erofs_warn("Please send a report to <[email protected]> if 
something is wrong.");
+       return 0;
+}
+
+static int erofs_compressor_deflate_setlevel(struct erofs_compress *c,
+                                            int compression_level)
+{
+       void *s;
+
+       if (c->private_data) {
+               kite_deflate_end(c->private_data);
+               c->private_data = NULL;
+       }
+
+       if (compression_level < 0)
+               compression_level = erofs_compressor_deflate.default_level;
+
+       s = kite_deflate_init(compression_level, cfg.c_dict_size);
+       if (IS_ERR(s))
+               return PTR_ERR(s);
+
+       c->private_data = s;
+       c->compression_level = compression_level;
+       return 0;
+}
+
+const struct erofs_compressor erofs_compressor_deflate = {
+       .name = "deflate",
+       .default_level = 1,
+       .best_level = 9,
+       .init = compressor_deflate_init,
+       .exit = compressor_deflate_exit,
+       .setlevel = erofs_compressor_deflate_setlevel,
+       .compress_destsize = deflate_compress_destsize,
+};
-- 
2.24.4

Reply via email to