btrfs: rename btrfs_compress_op to btrfs_compress_levels

Since all workspace managers are per-fs, there is no need nor no way to
store them inside btrfs_compress_op::wsm anymore.

With that said, we can do the following modifications:

- Remove zstd_workspace_mananger::ops
  Zstd always grab the global btrfs_compress_op[].
- Remove btrfs_compress_op::wsm member
- Rename btrfs_compress_op to btrfs_compress_levels

This should make it more clear that btrfs_compress_levels structures are
only to indicate the levels of each compress algorithm.

Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Author: adam900710

fs/btrfs/compression.c

@@ -727,9 +727,9 @@ static struct list_head *alloc_heuristic_ws(struct btrfs_fs_info *fs_info)
 	return ERR_PTR(-ENOMEM);
 }
 
-const struct btrfs_compress_op btrfs_heuristic_compress = { 0 };
+const struct btrfs_compress_levels btrfs_heuristic_compress = { 0 };
 
-static const struct btrfs_compress_op * const btrfs_compress_op[] = {
+static const struct btrfs_compress_levels * const btrfs_compress_levels[] = {
 	/* The heuristic is represented as compression type 0 */
 	&btrfs_heuristic_compress,
 	&btrfs_zlib_compress,
@@ -981,12 +981,12 @@ static void put_workspace(struct btrfs_fs_info *fs_info, int type, struct list_h
  */
 static int btrfs_compress_set_level(unsigned int type, int level)
 {
-	const struct btrfs_compress_op *ops = btrfs_compress_op[type];
+	const struct btrfs_compress_levels *levels = btrfs_compress_levels[type];
 
 	if (level == 0)
-		level = ops->default_level;
+		level = levels->default_level;
 	else
-		level = clamp(level, ops->min_level, ops->max_level);
+		level = clamp(level, levels->min_level, levels->max_level);
 
 	return level;
 }
@@ -996,9 +996,9 @@ static int btrfs_compress_set_level(unsigned int type, int level)
  */
 bool btrfs_compress_level_valid(unsigned int type, int level)
 {
-	const struct btrfs_compress_op *ops = btrfs_compress_op[type];
+	const struct btrfs_compress_levels *levels = btrfs_compress_levels[type];
 
-	return ops->min_level <= level && level <= ops->max_level;
+	return levels->min_level <= level && level <= levels->max_level;
 }
 
 /* Wrapper around find_get_page(), with extra error message. */

fs/btrfs/compression.h

@@ -129,8 +129,7 @@ struct workspace_manager {
 struct list_head *btrfs_get_workspace(struct btrfs_fs_info *fs_info, int type, int level);
 void btrfs_put_workspace(struct btrfs_fs_info *fs_info, int type, struct list_head *ws);
 
-struct btrfs_compress_op {
-	struct workspace_manager *workspace_manager;
+struct btrfs_compress_levels {
 	/* Maximum level supported by the compression algorithm */
 	int min_level;
 	int max_level;
@@ -140,10 +139,10 @@ struct btrfs_compress_op {
 /* The heuristic workspaces are managed via the 0th workspace manager */
 #define BTRFS_NR_WORKSPACE_MANAGERS	BTRFS_NR_COMPRESS_TYPES
 
-extern const struct btrfs_compress_op btrfs_heuristic_compress;
-extern const struct btrfs_compress_op btrfs_zlib_compress;
-extern const struct btrfs_compress_op btrfs_lzo_compress;
-extern const struct btrfs_compress_op btrfs_zstd_compress;
+extern const struct btrfs_compress_levels btrfs_heuristic_compress;
+extern const struct btrfs_compress_levels btrfs_zlib_compress;
+extern const struct btrfs_compress_levels btrfs_lzo_compress;
+extern const struct btrfs_compress_levels btrfs_zstd_compress;
 
 const char* btrfs_compress_type2str(enum btrfs_compression_type type);
 bool btrfs_compress_is_valid_type(const char *str, size_t len);

fs/btrfs/lzo.c

@@ -486,7 +486,7 @@ int lzo_decompress(struct list_head *ws, const u8 *data_in,
 	return ret;
 }
 
-const struct btrfs_compress_op btrfs_lzo_compress = {
+const struct btrfs_compress_levels  btrfs_lzo_compress = {
 	.max_level		= 1,
 	.default_level		= 1,
 };

fs/btrfs/zlib.c

@@ -480,7 +480,7 @@ int zlib_decompress(struct list_head *ws, const u8 *data_in,
 	return ret;
 }
 
-const struct btrfs_compress_op btrfs_zlib_compress = {
+const struct btrfs_compress_levels btrfs_zlib_compress = {
 	.min_level		= 1,
 	.max_level		= 9,
 	.default_level		= BTRFS_ZLIB_DEFAULT_LEVEL,

fs/btrfs/zstd.c

@@ -77,7 +77,6 @@ struct workspace {
  */
 
 struct zstd_workspace_manager {
-	const struct btrfs_compress_op *ops;
 	spinlock_t lock;
 	struct list_head lru_list;
 	struct list_head idle_ws[ZSTD_BTRFS_MAX_LEVEL];
@@ -190,7 +189,6 @@ int zstd_alloc_workspace_manager(struct btrfs_fs_info *fs_info)
 	if (!zwsm)
 		return -ENOMEM;
 	zstd_calc_ws_mem_sizes();
-	zwsm->ops = &btrfs_zstd_compress;
 	spin_lock_init(&zwsm->lock);
 	init_waitqueue_head(&zwsm->wait);
 	timer_setup(&zwsm->timer, zstd_reclaim_timer_fn, 0);
@@ -727,7 +725,7 @@ int zstd_decompress(struct list_head *ws, const u8 *data_in,
 	return ret;
 }
 
-const struct btrfs_compress_op btrfs_zstd_compress = {
+const struct btrfs_compress_levels btrfs_zstd_compress = {
 	.min_level	= ZSTD_BTRFS_MIN_LEVEL,
 	.max_level	= ZSTD_BTRFS_MAX_LEVEL,
 	.default_level	= ZSTD_BTRFS_DEFAULT_LEVEL,