erofs: move each decompressor to its own source file

Thus *_config() function declarations can be avoided.
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240709094106.3018109-1-hsiangkao@linux.alibaba.com

fs/erofs/compress.h

@@ -81,21 +81,11 @@ static inline bool z_erofs_put_shortlivedpage(struct page **pagepool,
 	return true;
 }
 
+extern const struct z_erofs_decompressor z_erofs_lzma_decomp;
+extern const struct z_erofs_decompressor z_erofs_deflate_decomp;
+extern const struct z_erofs_decompressor z_erofs_zstd_decomp;
+extern const struct z_erofs_decompressor *z_erofs_decomp[];
+
 int z_erofs_fixup_insize(struct z_erofs_decompress_req *rq, const char *padbuf,
 			 unsigned int padbufsize);
-extern const struct z_erofs_decompressor erofs_decompressors[];
-
-/* prototypes for specific algorithms */
-int z_erofs_load_lzma_config(struct super_block *sb,
-			struct erofs_super_block *dsb, void *data, int size);
-int z_erofs_load_deflate_config(struct super_block *sb,
-			struct erofs_super_block *dsb, void *data, int size);
-int z_erofs_load_zstd_config(struct super_block *sb,
-			struct erofs_super_block *dsb, void *data, int size);
-int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
-			    struct page **pagepool);
-int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
-			       struct page **pagepool);
-int z_erofs_zstd_decompress(struct z_erofs_decompress_req *rq,
-			    struct page **pgpl);
 #endif

fs/erofs/decompressor.c

@@ -371,40 +371,28 @@ static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
 	return 0;
 }
 
-const struct z_erofs_decompressor erofs_decompressors[] = {
-	[Z_EROFS_COMPRESSION_SHIFTED] = {
+const struct z_erofs_decompressor *z_erofs_decomp[] = {
+	[Z_EROFS_COMPRESSION_SHIFTED] = &(const struct z_erofs_decompressor) {
 		.decompress = z_erofs_transform_plain,
 		.name = "shifted"
 	},
-	[Z_EROFS_COMPRESSION_INTERLACED] = {
+	[Z_EROFS_COMPRESSION_INTERLACED] = &(const struct z_erofs_decompressor) {
 		.decompress = z_erofs_transform_plain,
 		.name = "interlaced"
 	},
-	[Z_EROFS_COMPRESSION_LZ4] = {
+	[Z_EROFS_COMPRESSION_LZ4] = &(const struct z_erofs_decompressor) {
 		.config = z_erofs_load_lz4_config,
 		.decompress = z_erofs_lz4_decompress,
 		.name = "lz4"
 	},
 #ifdef CONFIG_EROFS_FS_ZIP_LZMA
-	[Z_EROFS_COMPRESSION_LZMA] = {
-		.config = z_erofs_load_lzma_config,
-		.decompress = z_erofs_lzma_decompress,
-		.name = "lzma"
-	},
+	[Z_EROFS_COMPRESSION_LZMA] = &z_erofs_lzma_decomp,
 #endif
 #ifdef CONFIG_EROFS_FS_ZIP_DEFLATE
-	[Z_EROFS_COMPRESSION_DEFLATE] = {
-		.config = z_erofs_load_deflate_config,
-		.decompress = z_erofs_deflate_decompress,
-		.name = "deflate"
-	},
+	[Z_EROFS_COMPRESSION_DEFLATE] = &z_erofs_deflate_decomp,
 #endif
 #ifdef CONFIG_EROFS_FS_ZIP_ZSTD
-	[Z_EROFS_COMPRESSION_ZSTD] = {
-		.config = z_erofs_load_zstd_config,
-		.decompress = z_erofs_zstd_decompress,
-		.name = "zstd"
-	},
+	[Z_EROFS_COMPRESSION_ZSTD] = &z_erofs_zstd_decomp,
 #endif
 };
 
@@ -432,6 +420,7 @@ int z_erofs_parse_cfgs(struct super_block *sb, struct erofs_super_block *dsb)
 	offset = EROFS_SUPER_OFFSET + sbi->sb_size;
 	alg = 0;
 	for (algs = sbi->available_compr_algs; algs; algs >>= 1, ++alg) {
+		const struct z_erofs_decompressor *dec = z_erofs_decomp[alg];
 		void *data;
 
 		if (!(algs & 1))
@@ -443,16 +432,13 @@ int z_erofs_parse_cfgs(struct super_block *sb, struct erofs_super_block *dsb)
 			break;
 		}
 
-		if (alg >= ARRAY_SIZE(erofs_decompressors) ||
-		    !erofs_decompressors[alg].config) {
+		if (alg < Z_EROFS_COMPRESSION_MAX && dec && dec->config) {
+			ret = dec->config(sb, dsb, data, size);
+		} else {
 			erofs_err(sb, "algorithm %d isn't enabled on this kernel",
 				  alg);
 			ret = -EOPNOTSUPP;
-		} else {
-			ret = erofs_decompressors[alg].config(sb,
-					dsb, data, size);
 		}
-
 		kfree(data);
 		if (ret)
 			break;

fs/erofs/decompressor_deflate.c

@@ -49,7 +49,7 @@ int __init z_erofs_deflate_init(void)
 	return 0;
 }
 
-int z_erofs_load_deflate_config(struct super_block *sb,
+static int z_erofs_load_deflate_config(struct super_block *sb,
 			struct erofs_super_block *dsb, void *data, int size)
 {
 	struct z_erofs_deflate_cfgs *dfl = data;
@@ -97,8 +97,8 @@ int z_erofs_load_deflate_config(struct super_block *sb,
 	return -ENOMEM;
 }
 
-int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
-			       struct page **pgpl)
+static int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
+				      struct page **pgpl)
 {
 	const unsigned int nrpages_out =
 		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -252,3 +252,9 @@ int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
 	wake_up(&z_erofs_deflate_wq);
 	return err;
 }
+
+const struct z_erofs_decompressor z_erofs_deflate_decomp = {
+	.config = z_erofs_load_deflate_config,
+	.decompress = z_erofs_deflate_decompress,
+	.name = "deflate",
+};

fs/erofs/decompressor_lzma.c

@@ -70,7 +70,7 @@ int __init z_erofs_lzma_init(void)
 	return 0;
 }
 
-int z_erofs_load_lzma_config(struct super_block *sb,
+static int z_erofs_load_lzma_config(struct super_block *sb,
 			struct erofs_super_block *dsb, void *data, int size)
 {
 	static DEFINE_MUTEX(lzma_resize_mutex);
@@ -147,8 +147,8 @@ int z_erofs_load_lzma_config(struct super_block *sb,
 	return err;
 }
 
-int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
-			    struct page **pgpl)
+static int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
+				   struct page **pgpl)
 {
 	const unsigned int nrpages_out =
 		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -293,3 +293,9 @@ int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
 	wake_up(&z_erofs_lzma_wq);
 	return err;
 }
+
+const struct z_erofs_decompressor z_erofs_lzma_decomp = {
+	.config = z_erofs_load_lzma_config,
+	.decompress = z_erofs_lzma_decompress,
+	.name = "lzma"
+};

fs/erofs/decompressor_zstd.c

@@ -72,7 +72,7 @@ int __init z_erofs_zstd_init(void)
 	return 0;
 }
 
-int z_erofs_load_zstd_config(struct super_block *sb,
+static int z_erofs_load_zstd_config(struct super_block *sb,
 			struct erofs_super_block *dsb, void *data, int size)
 {
 	static DEFINE_MUTEX(zstd_resize_mutex);
@@ -135,8 +135,8 @@ int z_erofs_load_zstd_config(struct super_block *sb,
 	return strm ? -ENOMEM : 0;
 }
 
-int z_erofs_zstd_decompress(struct z_erofs_decompress_req *rq,
-			    struct page **pgpl)
+static int z_erofs_zstd_decompress(struct z_erofs_decompress_req *rq,
+				   struct page **pgpl)
 {
 	const unsigned int nrpages_out =
 		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -277,3 +277,9 @@ int z_erofs_zstd_decompress(struct z_erofs_decompress_req *rq,
 	wake_up(&z_erofs_zstd_wq);
 	return err;
 }
+
+const struct z_erofs_decompressor z_erofs_zstd_decomp = {
+	.config = z_erofs_load_zstd_config,
+	.decompress = z_erofs_zstd_decompress,
+	.name = "zstd",
+};

fs/erofs/zdata.c

@@ -1213,7 +1213,7 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
 	struct z_erofs_pcluster *pcl = be->pcl;
 	unsigned int pclusterpages = z_erofs_pclusterpages(pcl);
 	const struct z_erofs_decompressor *decomp =
-				&erofs_decompressors[pcl->algorithmformat];
+				z_erofs_decomp[pcl->algorithmformat];
 	int i, err2;
 	struct page *page;
 	bool overlapped;