From: Luis Chamberlain <mcgrof@xxxxxxxxxx> Align the index to the mapping_min_order number of pages in filemap_get_pages(). Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx> --- generic/451 triggers a crash in this path for bs = 16k. mm/filemap.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index e4d46f79e95d..8a4bbddcf575 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2558,14 +2558,17 @@ static int filemap_get_pages(struct kiocb *iocb, size_t count, { struct file *filp = iocb->ki_filp; struct address_space *mapping = filp->f_mapping; + unsigned int min_order = mapping_min_folio_order(mapping); + unsigned int nrpages = 1UL << min_order; struct file_ra_state *ra = &filp->f_ra; - pgoff_t index = iocb->ki_pos >> PAGE_SHIFT; + pgoff_t index = round_down(iocb->ki_pos >> PAGE_SHIFT, nrpages); pgoff_t last_index; struct folio *folio; int err = 0; /* "last_index" is the index of the page beyond the end of the read */ last_index = DIV_ROUND_UP(iocb->ki_pos + count, PAGE_SIZE); + last_index = round_up(last_index, nrpages); retry: if (fatal_signal_pending(current)) return -EINTR; @@ -2581,8 +2584,7 @@ static int filemap_get_pages(struct kiocb *iocb, size_t count, if (!folio_batch_count(fbatch)) { if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_WAITQ)) return -EAGAIN; - err = filemap_create_folio(filp, mapping, - iocb->ki_pos >> PAGE_SHIFT, fbatch); + err = filemap_create_folio(filp, mapping, index, fbatch); if (err == AOP_TRUNCATED_PAGE) goto retry; return err; -- 2.40.1