Commit 966edfb0 authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: rename some generic methods in decompressor 

Previously, some LZ4 methods were named with `generic'. However, while
evaluating the effective LZMA approach, it seems they aren't quite
generic at all (e.g. no need preparing dstpages for most LZMA cases.)

Avoid such naming instead.

Link: https://lore.kernel.org/r/20211010213145.17462-7-xiang@kernel.org


Acked-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 0a434e0a

fs/erofs/decompressor.c

+30 −33
Original line number Diff line number Diff line
@@ -17,13 +17,8 @@ 
#endif



struct z_erofs_decompressor {

	/*

	 * if destpages have sparsed pages, fill them with bounce pages.

	 * it also check whether destpages indicate continuous physical memory.

	 */

	int (*prepare_destpages)(struct z_erofs_decompress_req *rq,

	int (*decompress)(struct z_erofs_decompress_req *rq,

			  struct list_head *pagepool);

	int (*decompress)(struct z_erofs_decompress_req *rq, u8 *out);

	char *name;

};
@@ -63,7 +58,11 @@ int z_erofs_load_lz4_config(struct super_block *sb, 
	return erofs_pcpubuf_growsize(sbi->lz4.max_pclusterblks);

}



static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq,

/*

 * Fill all gaps with bounce pages if it's a sparse page list. Also check if

 * all physical pages are consecutive, which can be seen for moderate CR.

 */

static int z_erofs_lz4_prepare_dstpages(struct z_erofs_decompress_req *rq,

					struct list_head *pagepool)

{

	const unsigned int nr =
@@ -119,7 +118,7 @@ static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq, 
	return kaddr ? 1 : 0;

}



static void *z_erofs_handle_inplace_io(struct z_erofs_decompress_req *rq,

static void *z_erofs_lz4_handle_inplace_io(struct z_erofs_decompress_req *rq,

			void *inpage, unsigned int *inputmargin, int *maptype,

			bool support_0padding)

{
@@ -189,7 +188,8 @@ static void *z_erofs_handle_inplace_io(struct z_erofs_decompress_req *rq, 
	return src;

}



static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)

static int z_erofs_lz4_decompress_mem(struct z_erofs_decompress_req *rq,

				      u8 *out)

{

	unsigned int inputmargin;

	u8 *headpage, *src;
@@ -216,8 +216,8 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out) 
	}



	rq->inputsize -= inputmargin;

	src = z_erofs_handle_inplace_io(rq, headpage, &inputmargin, &maptype,

					support_0padding);

	src = z_erofs_lz4_handle_inplace_io(rq, headpage, &inputmargin,

					    &maptype, support_0padding);

	if (IS_ERR(src))

		return PTR_ERR(src);
@@ -259,23 +259,11 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out) 
	return ret;

}



static struct z_erofs_decompressor decompressors[] = {

	[Z_EROFS_COMPRESSION_SHIFTED] = {

		.name = "shifted"

	},

	[Z_EROFS_COMPRESSION_LZ4] = {

		.prepare_destpages = z_erofs_lz4_prepare_destpages,

		.decompress = z_erofs_lz4_decompress,

		.name = "lz4"

	},

};



static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,

static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,

				  struct list_head *pagepool)

{

	const unsigned int nrpages_out =

		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;

	const struct z_erofs_decompressor *alg = decompressors + rq->alg;

	unsigned int dst_maptype;

	void *dst;

	int ret;
@@ -289,7 +277,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq, 
	}



	/* general decoding path which can be used for all cases */

	ret = alg->prepare_destpages(rq, pagepool);

	ret = z_erofs_lz4_prepare_dstpages(rq, pagepool);

	if (ret < 0)

		return ret;

	if (ret) {
@@ -304,7 +292,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq, 
	dst_maptype = 2;



dstmap_out:

	ret = alg->decompress(rq, dst + rq->pageofs_out);

	ret = z_erofs_lz4_decompress_mem(rq, dst + rq->pageofs_out);



	if (!dst_maptype)

		kunmap_atomic(dst);
@@ -313,7 +301,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq, 
	return ret;

}



static int z_erofs_shifted_transform(const struct z_erofs_decompress_req *rq,

static int z_erofs_shifted_transform(struct z_erofs_decompress_req *rq,

				     struct list_head *pagepool)

{

	const unsigned int nrpages_out =
@@ -352,10 +340,19 @@ static int z_erofs_shifted_transform(const struct z_erofs_decompress_req *rq, 
	return 0;

}



static struct z_erofs_decompressor decompressors[] = {

	[Z_EROFS_COMPRESSION_SHIFTED] = {

		.decompress = z_erofs_shifted_transform,

		.name = "shifted"

	},

	[Z_EROFS_COMPRESSION_LZ4] = {

		.decompress = z_erofs_lz4_decompress,

		.name = "lz4"

	},

};



int z_erofs_decompress(struct z_erofs_decompress_req *rq,

		       struct list_head *pagepool)

{

	if (rq->alg == Z_EROFS_COMPRESSION_SHIFTED)

		return z_erofs_shifted_transform(rq, pagepool);

	return z_erofs_decompress_generic(rq, pagepool);

	return decompressors[rq->alg].decompress(rq, pagepool);

}