From e4c1cf523d820730a86cae2c6d55924833b6f7ac Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Thu, 17 Aug 2023 16:28:09 +0800 Subject: [PATCH] erofs: tidy up z_erofs_do_read_page() - Fix a typo: spiltted => split; - Move !EROFS_MAP_MAPPED and EROFS_MAP_FRAGMENT upwards; - Increase `split` in advance to avoid unnecessary repeats. Reviewed-by: Yue Hu Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20230817082813.81180-4-hsiangkao@linux.alibaba.com --- fs/erofs/zdata.c | 53 ++++++++++++++++++++++++----------------------------- 1 file changed, 24 insertions(+), 29 deletions(-) diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index 9b67991..6c78566 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -981,49 +981,34 @@ 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, len, spiltted; + unsigned int cur, end, len, split; int err = 0; - /* register locked file pages as online pages in pack */ z_erofs_onlinepage_init(page); - spiltted = 0; + split = 0; end = PAGE_SIZE; repeat: - cur = end - 1; - - if (offset + cur < map->m_la || - offset + cur >= map->m_la + map->m_llen) { + if (offset + end - 1 < map->m_la || + offset + end - 1 >= map->m_la + map->m_llen) { z_erofs_pcluster_end(fe); - map->m_la = offset + cur; + map->m_la = offset + end - 1; map->m_llen = 0; err = z_erofs_map_blocks_iter(inode, map, 0); if (err) goto out; - } else if (fe->pcl) { - goto hitted; } - if ((map->m_flags & EROFS_MAP_MAPPED) && - !(map->m_flags & EROFS_MAP_FRAGMENT)) { - err = z_erofs_pcluster_begin(fe); - if (err) - goto out; - } -hitted: - /* - * Ensure the current partial page belongs to this submit chain rather - * than other concurrent submit chains or the noio(bypass) chain since - * those chains are handled asynchronously thus the page cannot be used - * for inplace I/O or bvpage (should be processed in a strict order.) - */ - tight &= (fe->mode > Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE); + cur = offset > map->m_la ? 0 : map->m_la - offset; + /* bump split parts first to avoid several separate cases */ + ++split; - cur = end - min_t(erofs_off_t, offset + end - map->m_la, end); if (!(map->m_flags & EROFS_MAP_MAPPED)) { zero_user_segment(page, cur, end); + tight = false; goto next_part; } + if (map->m_flags & EROFS_MAP_FRAGMENT) { erofs_off_t fpos = offset + cur - map->m_la; @@ -1032,12 +1017,24 @@ hitted: EROFS_I(inode)->z_fragmentoff + fpos); if (err) goto out; - ++spiltted; tight = false; goto next_part; } - exclusive = (!cur && (!spiltted || tight)); + if (!fe->pcl) { + err = z_erofs_pcluster_begin(fe); + if (err) + goto out; + } + + /* + * Ensure the current partial page belongs to this submit chain rather + * than other concurrent submit chains or the noio(bypass) chain since + * those chains are handled asynchronously thus the page cannot be used + * for inplace I/O or bvpage (should be processed in a strict order.) + */ + tight &= (fe->mode > Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE); + exclusive = (!cur && ((split <= 1) || tight)); if (cur) tight &= (fe->mode >= Z_EROFS_PCLUSTER_FOLLOWED); @@ -1050,8 +1047,6 @@ hitted: goto out; z_erofs_onlinepage_split(page); - /* bump up the number of spiltted parts of a page */ - ++spiltted; if (fe->pcl->pageofs_out != (map->m_la & ~PAGE_MASK)) fe->pcl->multibases = true; if (fe->pcl->length < offset + end - map->m_la) { -- 2.7.4