From: Joanne Koong <joannelkoong@gmail.com> For the direct io case, the pages from userspace may be part of a huge folio, even if all folios in the page cache for fuse are small. Fix the logic for calculating the offset and length of the folio for the direct io case, which currently incorrectly assumes that all folios encountered are one page size. Fixes: 3b97c3652d91 ("fuse: convert direct io to use folios") Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com> Reviewed-by: Bernd Schubert <bschubert@ddn.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> --- fs/fuse/file.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 5eb1571960f5..a1bf0ad5ffeb 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1476,18 +1476,22 @@ static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii, nbytes += ret; - ret += start; - /* Currently, all folios in FUSE are one page */ - nfolios = DIV_ROUND_UP(ret, PAGE_SIZE); - - ap->descs[ap->num_folios].offset = start; - fuse_folio_descs_length_init(ap->descs, ap->num_folios, nfolios); - for (i = 0; i < nfolios; i++) - ap->folios[i + ap->num_folios] = page_folio(pages[i]); - - ap->num_folios += nfolios; - ap->descs[ap->num_folios - 1].length -= - (PAGE_SIZE - ret) & (PAGE_SIZE - 1); + nfolios = DIV_ROUND_UP(ret + start, PAGE_SIZE); + + for (i = 0; i < nfolios; i++) { + struct folio *folio = page_folio(pages[i]); + unsigned int offset = start + + (folio_page_idx(folio, pages[i]) << PAGE_SHIFT); + unsigned int len = min_t(unsigned int, ret, PAGE_SIZE - start); + + ap->descs[ap->num_folios].offset = offset; + ap->descs[ap->num_folios].length = len; + ap->folios[ap->num_folios] = folio; + start = 0; + ret -= len; + ap->num_folios++; + } + nr_pages += nfolios; } kfree(pages); -- 2.46.1