From: Joanne Koong Date: Wed, 11 Dec 2024 20:55:56 +0000 (-0800) Subject: fuse: fix direct io folio offset and length calculation X-Git-Tag: v6.13-rc7~23^2~7^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7a4f541873734f41f9645ec147cfae72ef3ffd00;p=thirdparty%2Flinux.git fuse: fix direct io folio offset and length calculation 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 Reviewed-by: Jingbo Xu Reviewed-by: Bernd Schubert Signed-off-by: Miklos Szeredi --- diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 88d0946b5bc98..15b08d6a57398 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1557,18 +1557,22 @@ 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);