btrfs: compression: export alloc/free/get/put callbacks of all algos

The indirect calls will be replaced by a switch in compression.c.
(Switch is faster than indirect calls with when Spectre mitigations are
enabled).
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/compression.c

@@ -36,6 +36,10 @@ 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);
+struct list_head *zlib_alloc_workspace(unsigned int level);
+void zlib_free_workspace(struct list_head *ws);
+struct list_head *zlib_get_workspace(unsigned int level);
+void zlib_put_workspace(struct list_head *ws);
 
 int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
 		u64 start, struct page **pages, unsigned long *out_pages,
@@ -44,6 +48,10 @@ 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);
+struct list_head *lzo_alloc_workspace(unsigned int level);
+void lzo_free_workspace(struct list_head *ws);
+struct list_head *lzo_get_workspace(unsigned int level);
+void lzo_put_workspace(struct list_head *ws);
 
 int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
 		u64 start, struct page **pages, unsigned long *out_pages,
@@ -54,6 +62,10 @@ int zstd_decompress(struct list_head *ws, unsigned char *data_in,
 		size_t destlen);
 void zstd_init_workspace_manager(void);
 void zstd_cleanup_workspace_manager(void);
+struct list_head *zstd_alloc_workspace(unsigned int level);
+void zstd_free_workspace(struct list_head *ws);
+struct list_head *zstd_get_workspace(unsigned int level);
+void zstd_put_workspace(struct list_head *ws);
 
 static const char* const btrfs_compress_types[] = { "", "zlib", "lzo", "zstd" };
 

fs/btrfs/lzo.c

@@ -63,17 +63,17 @@ struct workspace {
 
 static struct workspace_manager wsm;
 
-static struct list_head *lzo_get_workspace(unsigned int level)
+struct list_head *lzo_get_workspace(unsigned int level)
 {
 	return btrfs_get_workspace(&wsm, level);
 }
 
-static void lzo_put_workspace(struct list_head *ws)
+void lzo_put_workspace(struct list_head *ws)
 {
 	btrfs_put_workspace(&wsm, ws);
 }
 
-static void lzo_free_workspace(struct list_head *ws)
+void lzo_free_workspace(struct list_head *ws)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 
@@ -83,7 +83,7 @@ static void lzo_free_workspace(struct list_head *ws)
 	kfree(workspace);
 }
 
-static struct list_head *lzo_alloc_workspace(unsigned int level)
+struct list_head *lzo_alloc_workspace(unsigned int level)
 {
 	struct workspace *workspace;
 

fs/btrfs/zlib.c

@@ -29,7 +29,7 @@ struct workspace {
 
 static struct workspace_manager wsm;
 
-static struct list_head *zlib_get_workspace(unsigned int level)
+struct list_head *zlib_get_workspace(unsigned int level)
 {
 	struct list_head *ws = btrfs_get_workspace(&wsm, level);
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
@@ -39,12 +39,12 @@ static struct list_head *zlib_get_workspace(unsigned int level)
 	return ws;
 }
 
-static void zlib_put_workspace(struct list_head *ws)
+void zlib_put_workspace(struct list_head *ws)
 {
 	btrfs_put_workspace(&wsm, ws);
 }
 
-static void zlib_free_workspace(struct list_head *ws)
+void zlib_free_workspace(struct list_head *ws)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 
@@ -53,7 +53,7 @@ static void zlib_free_workspace(struct list_head *ws)
 	kfree(workspace);
 }
 
-static struct list_head *zlib_alloc_workspace(unsigned int level)
+struct list_head *zlib_alloc_workspace(unsigned int level)
 {
 	struct workspace *workspace;
 	int workspacesize;

fs/btrfs/zstd.c

@@ -91,9 +91,8 @@ static inline struct workspace *list_to_workspace(struct list_head *list)
 	return container_of(list, struct workspace, list);
 }
 
-static void zstd_free_workspace(struct list_head *ws);
-static struct list_head *zstd_alloc_workspace(unsigned int level);
-
+void zstd_free_workspace(struct list_head *ws);
+struct list_head *zstd_alloc_workspace(unsigned int level);
 /*
  * zstd_reclaim_timer_fn - reclaim timer
  * @t: timer
@@ -261,7 +260,7 @@ static struct list_head *zstd_find_workspace(unsigned int level)
  * attempt to allocate a new workspace.  If we fail to allocate one due to
  * memory pressure, go to sleep waiting for the max level workspace to free up.
  */
-static struct list_head *zstd_get_workspace(unsigned int level)
+struct list_head *zstd_get_workspace(unsigned int level)
 {
 	struct list_head *ws;
 	unsigned int nofs_flag;
@@ -302,7 +301,7 @@ static struct list_head *zstd_get_workspace(unsigned int level)
  * isn't set, it is also set here.  Only the max level workspace tries and wakes
  * up waiting workspaces.
  */
-static void zstd_put_workspace(struct list_head *ws)
+void zstd_put_workspace(struct list_head *ws)
 {
 	struct workspace *workspace = list_to_workspace(ws);
 
@@ -332,7 +331,7 @@ static void zstd_put_workspace(struct list_head *ws)
 		cond_wake_up(&wsm.wait);
 }
 
-static void zstd_free_workspace(struct list_head *ws)
+void zstd_free_workspace(struct list_head *ws)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 
@@ -341,7 +340,7 @@ static void zstd_free_workspace(struct list_head *ws)
 	kfree(workspace);
 }
 
-static struct list_head *zstd_alloc_workspace(unsigned int level)
+struct list_head *zstd_alloc_workspace(unsigned int level)
 {
 	struct workspace *workspace;