Commit 67139e36 authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: introduce `z_erofs_parse_in_bvecs' 



`z_erofs_decompress_pcluster()' is too long therefore it'd be better
to introduce another helper to parse compressed pages (or laterly,
compressed bvecs.)

BTW, since `compressed_bvecs' is too long as a part of the function
name, `in_bvecs' is used here instead.

Acked-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220715154203.48093-7-hsiangkao@linux.alibaba.com
parent 387bab87

fs/erofs/zdata.c

+80 −52
Original line number Diff line number Diff line
@@ -913,6 +913,76 @@ static int z_erofs_parse_out_bvecs(struct z_erofs_pcluster *pcl, 
	return err;

}



static struct page **z_erofs_parse_in_bvecs(struct erofs_sb_info *sbi,

			struct z_erofs_pcluster *pcl, struct page **pages,

			struct page **pagepool, bool *overlapped)

{

	unsigned int pclusterpages = z_erofs_pclusterpages(pcl);

	struct page **compressed_pages;

	int i, err = 0;



	/* XXX: will have a better approach in the following commits */

	compressed_pages = kmalloc_array(pclusterpages, sizeof(struct page *),

					 GFP_KERNEL | __GFP_NOFAIL);

	*overlapped = false;



	for (i = 0; i < pclusterpages; ++i) {

		unsigned int pagenr;

		struct page *page = pcl->compressed_pages[i];



		/* compressed pages ought to be present before decompressing */

		if (!page) {

			DBG_BUGON(1);

			continue;

		}

		compressed_pages[i] = page;



		if (z_erofs_is_inline_pcluster(pcl)) {

			if (!PageUptodate(page))

				err = -EIO;

			continue;

		}



		DBG_BUGON(z_erofs_page_is_invalidated(page));

		if (!z_erofs_is_shortlived_page(page)) {

			if (erofs_page_is_managed(sbi, page)) {

				if (!PageUptodate(page))

					err = -EIO;

				continue;

			}



			/*

			 * only if non-head page can be selected

			 * for inplace decompression

			 */

			pagenr = z_erofs_onlinepage_index(page);



			DBG_BUGON(pagenr >= pcl->nr_pages);

			if (pages[pagenr]) {

				DBG_BUGON(1);

				SetPageError(pages[pagenr]);

				z_erofs_onlinepage_endio(pages[pagenr]);

				err = -EFSCORRUPTED;

			}

			pages[pagenr] = page;



			*overlapped = true;

		}



		/* PG_error needs checking for all non-managed pages */

		if (PageError(page)) {

			DBG_BUGON(PageUptodate(page));

			err = -EIO;

		}

	}



	if (err) {

		kfree(compressed_pages);

		return ERR_PTR(err);

	}

	return compressed_pages;

}



static int z_erofs_decompress_pcluster(struct super_block *sb,

				       struct z_erofs_pcluster *pcl,

				       struct page **pagepool)
@@ -957,54 +1027,11 @@ static int z_erofs_decompress_pcluster(struct super_block *sb, 
		pages[i] = NULL;



	err = z_erofs_parse_out_bvecs(pcl, pages, pagepool);



	overlapped = false;

	compressed_pages = pcl->compressed_pages;



	for (i = 0; i < pclusterpages; ++i) {

		unsigned int pagenr;



		page = compressed_pages[i];

		/* all compressed pages ought to be valid */

		DBG_BUGON(!page);



		if (z_erofs_is_inline_pcluster(pcl)) {

			if (!PageUptodate(page))

				err = -EIO;

			continue;

		}



		DBG_BUGON(z_erofs_page_is_invalidated(page));

		if (!z_erofs_is_shortlived_page(page)) {

			if (erofs_page_is_managed(sbi, page)) {

				if (!PageUptodate(page))

					err = -EIO;

				continue;

			}



			/*

			 * only if non-head page can be selected

			 * for inplace decompression

			 */

			pagenr = z_erofs_onlinepage_index(page);



			DBG_BUGON(pagenr >= nr_pages);

			if (pages[pagenr]) {

				DBG_BUGON(1);

				SetPageError(pages[pagenr]);

				z_erofs_onlinepage_endio(pages[pagenr]);

				err = -EFSCORRUPTED;

			}

			pages[pagenr] = page;



			overlapped = true;

		}



		/* PG_error needs checking for all non-managed pages */

		if (PageError(page)) {

			DBG_BUGON(PageUptodate(page));

			err = -EIO;

		}

	compressed_pages = z_erofs_parse_in_bvecs(sbi, pcl, pages,

						pagepool, &overlapped);

	if (IS_ERR(compressed_pages)) {

		err = PTR_ERR(compressed_pages);

		compressed_pages = NULL;

	}



	if (err)
@@ -1040,21 +1067,22 @@ static int z_erofs_decompress_pcluster(struct super_block *sb, 
out:

	/* must handle all compressed pages before actual file pages */

	if (z_erofs_is_inline_pcluster(pcl)) {

		page = compressed_pages[0];

		WRITE_ONCE(compressed_pages[0], NULL);

		page = pcl->compressed_pages[0];

		WRITE_ONCE(pcl->compressed_pages[0], NULL);

		put_page(page);

	} else {

		for (i = 0; i < pclusterpages; ++i) {

			page = compressed_pages[i];

			page = pcl->compressed_pages[i];



			if (erofs_page_is_managed(sbi, page))

				continue;



			/* recycle all individual short-lived pages */

			(void)z_erofs_put_shortlivedpage(pagepool, page);

			WRITE_ONCE(compressed_pages[i], NULL);

			WRITE_ONCE(pcl->compressed_pages[i], NULL);

		}

	}

	kfree(compressed_pages);



	for (i = 0; i < nr_pages; ++i) {

		page = pages[i];