[PATCH v4 27/36] mm: Fix truncation for pages of arbitrary size

Matthew Wilcox
2020-05-15T13:18:10Z

Remove the assumption that a compound page is HPAGE_PMD_SIZE,
and the assumption that any page is PAGE_SIZE.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
mm/truncate.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/truncate.c b/mm/truncate.c
index dd9ebc1da356..dad384a4dc6d 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -168,7 +168,7 @@ void do_invalidatepage(struct page *page, unsigned int offset,
* 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 = hpage_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
--
2.26.2