Commit bd735bda authored by Jeffle Xu's avatar Jeffle Xu Committed by Gao Xiang
Browse files

erofs: implement fscache-based data read for inline layout 



Implement the data plane of reading data from data blobs over fscache
for inline layout.

For the heading non-inline part, the data plane for non-inline layout is
reused, while only the tail packing part needs special handling.

Signed-off-by: default avatarJeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220425122143.56815-20-jefflexu@linux.alibaba.com


Acked-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 1442b02b

fs/erofs/fscache.c

+32 −0
Original line number Diff line number Diff line
@@ -83,6 +83,33 @@ static int erofs_fscache_meta_readpage(struct file *data, struct page *page) 
	return ret;

}



static int erofs_fscache_readpage_inline(struct folio *folio,

					 struct erofs_map_blocks *map)

{

	struct super_block *sb = folio_mapping(folio)->host->i_sb;

	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;

	erofs_blk_t blknr;

	size_t offset, len;

	void *src, *dst;



	/* For tail packing layout, the offset may be non-zero. */

	offset = erofs_blkoff(map->m_pa);

	blknr = erofs_blknr(map->m_pa);

	len = map->m_llen;



	src = erofs_read_metabuf(&buf, sb, blknr, EROFS_KMAP);

	if (IS_ERR(src))

		return PTR_ERR(src);



	dst = kmap_local_folio(folio, 0);

	memcpy(dst, src + offset, len);

	memset(dst + len, 0, PAGE_SIZE - len);

	kunmap_local(dst);



	erofs_put_metabuf(&buf);

	return 0;

}



static int erofs_fscache_readpage(struct file *file, struct page *page)

{

	struct folio *folio = page_folio(page);
@@ -108,6 +135,11 @@ static int erofs_fscache_readpage(struct file *file, struct page *page) 
		goto out_uptodate;

	}



	if (map.m_flags & EROFS_MAP_META) {

		ret = erofs_fscache_readpage_inline(folio, &map);

		goto out_uptodate;

	}



	mdev = (struct erofs_map_dev) {

		.m_deviceid = map.m_deviceid,

		.m_pa = map.m_pa,