From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm/truncate: fix truncation for pages of arbitrary size Remove the assumption that a compound page is HPAGE_PMD_SIZE, and the assumption that any page is PAGE_SIZE. Link: https://lkml.kernel.org/r/20200908195539.25896-10-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Reviewed-by: SeongJae Park <sjpark@xxxxxxxxx> Cc: Huang Ying <ying.huang@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/truncate.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/truncate.c~mm-truncate-fix-truncation-for-pages-of-arbitrary-size +++ a/mm/truncate.c @@ -168,7 +168,7 @@ void do_invalidatepage(struct page *page * becomes orphaned. It will be left on the LRU and may even be mapped into * user pagetables if we're racing with filemap_fault(). * - * We need to bale out if page->mapping is no longer equal to the original + * We need to bail out if page->mapping is no longer equal to the original * mapping. This happens a) when the VM reclaimed the page while we waited on * its lock, b) when a concurrent invalidate_mapping_pages got there first and * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space. @@ -177,12 +177,12 @@ static void truncate_cleanup_page(struct address_space *mapping, struct page *page) { if (page_mapped(page)) { - pgoff_t nr = PageTransHuge(page) ? HPAGE_PMD_NR : 1; + unsigned int nr = thp_nr_pages(page); unmap_mapping_pages(mapping, page->index, nr, false); } if (page_has_private(page)) - do_invalidatepage(page, 0, PAGE_SIZE); + do_invalidatepage(page, 0, thp_size(page)); /* * Some filesystems seem to re-dirty the page even after _
