Complete read error handling paths for all three kinds of compressed pages:

1) For cache-managed pages, PG_uptodate will be checked since read_endio will unlock and SetPageUptodate for these pages;

2) For inplaced pages, read_endio cannot SetPageUptodate directly since it should be used to mark the final decompressed data, PG_error will be set with page locked for IO error instead;

3) For staging pages, PG_error is used, which is similar to what we do for inplaced pages.

Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support") Cc: stable@vger.kernel.org # 4.19+ Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Gao Xiang gaoxiang25@huawei.com ---

changelog v2: - [3/3] wrap bio->bi_private assignment into erofs_grab_bio() as suggested by Chao;

This series focus on fixing error handling when failed to read compresssed data due to previous incomplete paths.

In addition, the last 2 patches add IO error fault injection for reading paths, which I have used to test the first patch as well.

Thanks, Gao Xiang

drivers/staging/erofs/unzip_vle.c | 41 ++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 13 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c index bfd52ebd0403..45541be12972 100644 --- a/drivers/staging/erofs/unzip_vle.c +++ b/drivers/staging/erofs/unzip_vle.c @@ -973,6 +973,7 @@ static int z_erofs_vle_unzip(struct super_block *sb, overlapped = false; compressed_pages = grp->compressed_pages;

+ err = 0; for (i = 0; i < clusterpages; ++i) { unsigned int pagenr;

@@ -982,26 +983,39 @@ static int z_erofs_vle_unzip(struct super_block *sb, DBG_BUGON(!page); DBG_BUGON(!page->mapping);

- if (z_erofs_is_stagingpage(page)) - continue; + if (!z_erofs_is_stagingpage(page)) { #ifdef EROFS_FS_HAS_MANAGED_CACHE - if (page->mapping == MNGD_MAPPING(sbi)) { - DBG_BUGON(!PageUptodate(page)); - continue; - } + if (page->mapping == MNGD_MAPPING(sbi)) { + if (unlikely(!PageUptodate(page))) + err = -EIO; + continue; + } #endif

- /* only non-head page could be reused as a compressed page */ - pagenr = z_erofs_onlinepage_index(page); + /* + * only if non-head page can be selected + * for inplace decompression + */ + pagenr = z_erofs_onlinepage_index(page);

- DBG_BUGON(pagenr >= nr_pages); - DBG_BUGON(pages[pagenr]); - ++sparsemem_pages; - pages[pagenr] = page; + DBG_BUGON(pagenr >= nr_pages); + DBG_BUGON(pages[pagenr]); + ++sparsemem_pages; + pages[pagenr] = page; + + overlapped = true; + }

- overlapped = true; + /* PG_error needs checking for inplaced and staging pages */ + if (unlikely(PageError(page))) { + DBG_BUGON(PageUptodate(page)); + err = -EIO; + } }

+ if (unlikely(err)) + goto out; + llen = (nr_pages << PAGE_SHIFT) - work->pageofs;

if (z_erofs_vle_workgrp_fmt(grp) == Z_EROFS_VLE_WORKGRP_FMT_PLAIN) { @@ -1195,6 +1209,7 @@ pickup_page_for_submission(struct z_erofs_vle_workgroup *grp, if (page->mapping == mc) { WRITE_ONCE(grp->compressed_pages[nr], page);

+ ClearPageError(page); if (!PagePrivate(page)) { /* * impossible to be !PagePrivate(page) for