Commit 8b00be16 authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: simplify z_erofs_read_fragment() 



A trivial cleanup to make the fragment handling logic more clear.

Reviewed-by: default avatarYue Hu <huyue2@coolpad.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230817082813.81180-1-hsiangkao@linux.alibaba.com
parent d442495c

fs/erofs/zdata.c

+13 −26
Original line number Diff line number Diff line
@@ -932,34 +932,27 @@ static bool z_erofs_collector_end(struct z_erofs_decompress_frontend *fe) 
	return true;

}



static int z_erofs_read_fragment(struct inode *inode, erofs_off_t pos,

				 struct page *page, unsigned int pageofs,

				 unsigned int len)

static int z_erofs_read_fragment(struct super_block *sb, struct page *page,

			unsigned int cur, unsigned int end, erofs_off_t pos)

{

	struct super_block *sb = inode->i_sb;

	struct inode *packed_inode = EROFS_I_SB(inode)->packed_inode;

	struct inode *packed_inode = EROFS_SB(sb)->packed_inode;

	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;

	u8 *src, *dst;

	unsigned int i, cnt;

	unsigned int cnt;

	u8 *src;



	if (!packed_inode)

		return -EFSCORRUPTED;



	buf.inode = packed_inode;

	pos += EROFS_I(inode)->z_fragmentoff;

	for (i = 0; i < len; i += cnt) {

		cnt = min_t(unsigned int, len - i,

	for (; cur < end; cur += cnt, pos += cnt) {

		cnt = min_t(unsigned int, end - cur,

			    sb->s_blocksize - erofs_blkoff(sb, pos));

		src = erofs_bread(&buf, erofs_blknr(sb, pos), EROFS_KMAP);

		if (IS_ERR(src)) {

			erofs_put_metabuf(&buf);

			return PTR_ERR(src);

		}



		dst = kmap_local_page(page);

		memcpy(dst + pageofs + i, src + erofs_blkoff(sb, pos), cnt);

		kunmap_local(dst);

		pos += cnt;

		memcpy_to_page(page, cur, src + erofs_blkoff(sb, pos), cnt);

	}

	erofs_put_metabuf(&buf);

	return 0;
@@ -972,7 +965,7 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, 
	struct erofs_map_blocks *const map = &fe->map;

	const loff_t offset = page_offset(page);

	bool tight = true, exclusive;

	unsigned int cur, end, spiltted;

	unsigned int cur, end, len, spiltted;

	int err = 0;



	/* register locked file pages as online pages in pack */
@@ -1041,17 +1034,11 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe, 
		goto next_part;

	}

	if (map->m_flags & EROFS_MAP_FRAGMENT) {

		unsigned int pageofs, skip, len;

		erofs_off_t fpos = offset + cur - map->m_la;



		if (offset > map->m_la) {

			pageofs = 0;

			skip = offset - map->m_la;

		} else {

			pageofs = map->m_la & ~PAGE_MASK;

			skip = 0;

		}

		len = min_t(unsigned int, map->m_llen - skip, end - cur);

		err = z_erofs_read_fragment(inode, skip, page, pageofs, len);

		len = min_t(unsigned int, map->m_llen - fpos, end - cur);

		err = z_erofs_read_fragment(inode->i_sb, page, cur, cur + len,

				EROFS_I(inode)->z_fragmentoff + fpos);

		if (err)

			goto out;

		++spiltted;