btrfs: export compression and decompression callbacks

Export compress_pages, decompress_bio and decompress callbacks for all
compression algos. The indirect calls will be replaced by a switch.
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/compression.c

@@ -29,6 +29,30 @@
 #include "extent_io.h"
 #include "extent_map.h"
 
+int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
+		u64 start, struct page **pages, unsigned long *out_pages,
+		unsigned long *total_in, unsigned long *total_out);
+int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
+int zlib_decompress(struct list_head *ws, unsigned char *data_in,
+		struct page *dest_page, unsigned long start_byte, size_t srclen,
+		size_t destlen);
+
+int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
+		u64 start, struct page **pages, unsigned long *out_pages,
+		unsigned long *total_in, unsigned long *total_out);
+int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
+int lzo_decompress(struct list_head *ws, unsigned char *data_in,
+		struct page *dest_page, unsigned long start_byte, size_t srclen,
+		size_t destlen);
+
+int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
+		u64 start, struct page **pages, unsigned long *out_pages,
+		unsigned long *total_in, unsigned long *total_out);
+int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
+int zstd_decompress(struct list_head *ws, unsigned char *data_in,
+		struct page *dest_page, unsigned long start_byte, size_t srclen,
+		size_t destlen);
+
 static const char* const btrfs_compress_types[] = { "", "zlib", "lzo", "zstd" };
 
 const char* btrfs_compress_type2str(enum btrfs_compression_type type)

fs/btrfs/lzo.c

@@ -131,13 +131,9 @@ static inline size_t read_compress_length(const char *buf)
 	return le32_to_cpu(dlen);
 }
 
-static int lzo_compress_pages(struct list_head *ws,
-			      struct address_space *mapping,
-			      u64 start,
-			      struct page **pages,
-			      unsigned long *out_pages,
-			      unsigned long *total_in,
-			      unsigned long *total_out)
+int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
+		u64 start, struct page **pages, unsigned long *out_pages,
+		unsigned long *total_in, unsigned long *total_out)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	int ret = 0;
@@ -303,7 +299,7 @@ static int lzo_compress_pages(struct list_head *ws,
 	return ret;
 }
 
-static int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
+int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	int ret = 0, ret2;
@@ -444,10 +440,9 @@ static int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 	return ret;
 }
 
-static int lzo_decompress(struct list_head *ws, unsigned char *data_in,
-			  struct page *dest_page,
-			  unsigned long start_byte,
-			  size_t srclen, size_t destlen)
+int lzo_decompress(struct list_head *ws, unsigned char *data_in,
+		struct page *dest_page, unsigned long start_byte, size_t srclen,
+		size_t destlen)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	size_t in_len;

fs/btrfs/zlib.c

@@ -88,13 +88,9 @@ static struct list_head *zlib_alloc_workspace(unsigned int level)
 	return ERR_PTR(-ENOMEM);
 }
 
-static int zlib_compress_pages(struct list_head *ws,
-			       struct address_space *mapping,
-			       u64 start,
-			       struct page **pages,
-			       unsigned long *out_pages,
-			       unsigned long *total_in,
-			       unsigned long *total_out)
+int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
+		u64 start, struct page **pages, unsigned long *out_pages,
+		unsigned long *total_in, unsigned long *total_out)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	int ret;
@@ -228,7 +224,7 @@ static int zlib_compress_pages(struct list_head *ws,
 	return ret;
 }
 
-static int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
+int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	int ret = 0, ret2;
@@ -319,10 +315,9 @@ static int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 	return ret;
 }
 
-static int zlib_decompress(struct list_head *ws, unsigned char *data_in,
-			   struct page *dest_page,
-			   unsigned long start_byte,
-			   size_t srclen, size_t destlen)
+int zlib_decompress(struct list_head *ws, unsigned char *data_in,
+		struct page *dest_page, unsigned long start_byte, size_t srclen,
+		size_t destlen)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	int ret = 0;

fs/btrfs/zstd.c

@@ -367,13 +367,9 @@ static struct list_head *zstd_alloc_workspace(unsigned int level)
 	return ERR_PTR(-ENOMEM);
 }
 
-static int zstd_compress_pages(struct list_head *ws,
-		struct address_space *mapping,
-		u64 start,
-		struct page **pages,
-		unsigned long *out_pages,
-		unsigned long *total_in,
-		unsigned long *total_out)
+int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
+		u64 start, struct page **pages, unsigned long *out_pages,
+		unsigned long *total_in, unsigned long *total_out)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	ZSTD_CStream *stream;
@@ -548,7 +544,7 @@ static int zstd_compress_pages(struct list_head *ws,
 	return ret;
 }
 
-static int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
+int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	struct page **pages_in = cb->compressed_pages;
@@ -626,10 +622,9 @@ static int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 	return ret;
 }
 
-static int zstd_decompress(struct list_head *ws, unsigned char *data_in,
-		struct page *dest_page,
-		unsigned long start_byte,
-		size_t srclen, size_t destlen)
+int zstd_decompress(struct list_head *ws, unsigned char *data_in,
+		struct page *dest_page, unsigned long start_byte, size_t srclen,
+		size_t destlen)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	ZSTD_DStream *stream;