[PATCH v2 6/8] ntfs: implement codec ops for LZX and XPRESS

Implement the transparent compression codec ops for XPRESS (4K, 8K,
16K) and LZX (32K) algorithms. The xpress_scratch_size,
lzx_scratch_size, xpress_decompress_chunk, and lzx_decompress_chunk
wrappers provide unified interfaces and use per-call dynamic scratch
state allocation (avoiding global mutexed singletons).

Signed-off-by: Hyunchul Lee <[email protected]>
---
 fs/ntfs/lib/lzx_decompress.c    | 21 +++++++++++++++++++++
 fs/ntfs/lib/xpress_decompress.c | 34 ++++++++++++++++++++++++++++++++++
 fs/ntfs/ntfs_codec.h            |  6 ++++++
 3 files changed, 61 insertions(+)

diff --git a/fs/ntfs/lib/lzx_decompress.c b/fs/ntfs/lib/lzx_decompress.c
index 3b3c198d07e4..be040dce6e23 100644
--- a/fs/ntfs/lib/lzx_decompress.c
+++ b/fs/ntfs/lib/lzx_decompress.c
@@ -14,6 +14,7 @@
 
 #include "decompress_common.h"
 #include "lib.h"
+#include "../ntfs_codec.h"
 
 /* Number of literal byte values. */
 #define LZX_NUM_CHARS		256
@@ -608,3 +609,23 @@ void lzx_free_decompressor(struct lzx_decompressor *d)
 {
 	kfree(d);
 }
+
+static size_t lzx_scratch_size(u32 chunk_size)
+{
+	return sizeof(struct lzx_decompressor);
+}
+
+static int lzx_decompress_chunk(void *scratch, const void *src, size_t src_len,
+				void *dst, size_t dst_len, u32 chunk_size)
+{
+	struct lzx_decompressor *d = scratch;
+
+	return lzx_decompress(d, src, src_len, dst, dst_len);
+}
+
+const struct ntfs_codec_ops ntfs_lzx32k_codec_ops = {
+	.id = NTFS_CODEC_LZX32K,
+	.name = "lzx32k",
+	.scratch_size = lzx_scratch_size,
+	.decompress_chunk = lzx_decompress_chunk,
+};
diff --git a/fs/ntfs/lib/xpress_decompress.c b/fs/ntfs/lib/xpress_decompress.c
index 7066810ee6cd..cb212543268d 100644
--- a/fs/ntfs/lib/xpress_decompress.c
+++ b/fs/ntfs/lib/xpress_decompress.c
@@ -15,6 +15,7 @@
 
 #include "decompress_common.h"
 #include "lib.h"
+#include "../ntfs_codec.h"
 
 #define XPRESS_NUM_CHARS	256
 #define XPRESS_NUM_SYMBOLS	512
@@ -118,3 +119,36 @@ void xpress_free_decompressor(struct xpress_decompressor *d)
 {
 	kfree(d);
 }
+
+static size_t xpress_scratch_size(u32 chunk_size)
+{
+	return sizeof(struct xpress_decompressor);
+}
+
+static int xpress_decompress_chunk(void *scratch, const void *src,
+				   size_t src_len, void *dst, size_t dst_len,
+				   u32 chunk_size)
+{
+	return xpress_decompress(scratch, src, src_len, dst, dst_len);
+}
+
+const struct ntfs_codec_ops ntfs_xpress4k_codec_ops = {
+	.id = NTFS_CODEC_XPRESS4K,
+	.name = "xpress4k",
+	.scratch_size = xpress_scratch_size,
+	.decompress_chunk = xpress_decompress_chunk,
+};
+
+const struct ntfs_codec_ops ntfs_xpress8k_codec_ops = {
+	.id = NTFS_CODEC_XPRESS8K,
+	.name = "xpress8k",
+	.scratch_size = xpress_scratch_size,
+	.decompress_chunk = xpress_decompress_chunk,
+};
+
+const struct ntfs_codec_ops ntfs_xpress16k_codec_ops = {
+	.id = NTFS_CODEC_XPRESS16K,
+	.name = "xpress16k",
+	.scratch_size = xpress_scratch_size,
+	.decompress_chunk = xpress_decompress_chunk,
+};
diff --git a/fs/ntfs/ntfs_codec.h b/fs/ntfs/ntfs_codec.h
index 408b18561a03..6030055fb0c1 100644
--- a/fs/ntfs/ntfs_codec.h
+++ b/fs/ntfs/ntfs_codec.h
@@ -44,5 +44,11 @@ struct ntfs_codec_ops {
 };
 
 extern const struct ntfs_codec_ops ntfs_lznt1_codec_ops;
+#ifdef CONFIG_NTFS_FS_WOF_COMPRESSION
+extern const struct ntfs_codec_ops ntfs_xpress4k_codec_ops;
+extern const struct ntfs_codec_ops ntfs_xpress8k_codec_ops;
+extern const struct ntfs_codec_ops ntfs_xpress16k_codec_ops;
+extern const struct ntfs_codec_ops ntfs_lzx32k_codec_ops;
+#endif
 
 #endif /* _NTFS_CODEC_H */

-- 
2.43.0