Commit c5539762 authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: simplify z_erofs_transform_plain() 



Use memcpy_to_page() instead of open-coding them.

In addition, add a missing flush_dcache_page() even though almost all
modern architectures clear `PG_dcache_clean` flag for new file cache
pages so that it doesn't change anything in practice.

Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: default avatarYue Hu <huyue2@coolpad.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230627161240.331-2-hsiangkao@linux.alibaba.com


Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 123ec246

fs/erofs/decompressor.c

+8 −11
Original line number Diff line number Diff line
@@ -328,7 +328,7 @@ static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq, 
	const unsigned int lefthalf = rq->outputsize - righthalf;

	const unsigned int interlaced_offset =

		rq->alg == Z_EROFS_COMPRESSION_SHIFTED ? 0 : rq->pageofs_out;

	unsigned char *src, *dst;

	u8 *src;



	if (outpages > 2 && rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {

		DBG_BUGON(1);
@@ -341,22 +341,19 @@ static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq, 
	}



	src = kmap_local_page(rq->in[inpages - 1]) + rq->pageofs_in;

	if (rq->out[0]) {

		dst = kmap_local_page(rq->out[0]);

		memcpy(dst + rq->pageofs_out, src + interlaced_offset,

		       righthalf);

		kunmap_local(dst);

	}

	if (rq->out[0])

		memcpy_to_page(rq->out[0], rq->pageofs_out,

			       src + interlaced_offset, righthalf);



	if (outpages > inpages) {

		DBG_BUGON(!rq->out[outpages - 1]);

		if (rq->out[outpages - 1] != rq->in[inpages - 1]) {

			dst = kmap_local_page(rq->out[outpages - 1]);

			memcpy(dst, interlaced_offset ? src :

					(src + righthalf), lefthalf);

			kunmap_local(dst);

			memcpy_to_page(rq->out[outpages - 1], 0, src +

					(interlaced_offset ? 0 : righthalf),

				       lefthalf);

		} else if (!interlaced_offset) {

			memmove(src, src + righthalf, lefthalf);

			flush_dcache_page(rq->in[inpages - 1]);

		}

	}

	kunmap_local(src);