From 5cbc198ae08d84bd416b672ad8bd1222acd0855c Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 30 Nov 2016 15:54:19 -0800 Subject: mm: fix false-positive WARN_ON() in truncate/invalidate for hugetlb Hugetlb pages have ->index in size of the huge pages (PMD_SIZE or PUD_SIZE), not in PAGE_SIZE as other types of pages. This means we cannot user page_to_pgoff() to check whether we've got the right page for the radix-tree index. Let's introduce page_to_index() which would return radix-tree index for given page. We will be able to get rid of this once hugetlb will be switched to multi-order entries. Fixes: fc127da085c2 ("truncate: handle file thp") Link: http://lkml.kernel.org/r/20161123093053.mjbnvn5zwxw5e6lk@black.fi.intel.com Signed-off-by: Kirill A. Shutemov Reported-by: Doug Nelson Tested-by: Doug Nelson Reviewed-by: Naoya Horiguchi Cc: [4.8+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/pagemap.h | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index dd15d39e1985..7dbe9148b2f8 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -374,16 +374,13 @@ static inline struct page *read_mapping_page(struct address_space *mapping, } /* - * Get the offset in PAGE_SIZE. - * (TODO: hugepage should have ->index in PAGE_SIZE) + * Get index of the page with in radix-tree + * (TODO: remove once hugetlb pages will have ->index in PAGE_SIZE) */ -static inline pgoff_t page_to_pgoff(struct page *page) +static inline pgoff_t page_to_index(struct page *page) { pgoff_t pgoff; - if (unlikely(PageHeadHuge(page))) - return page->index << compound_order(page); - if (likely(!PageTransTail(page))) return page->index; @@ -396,6 +393,18 @@ static inline pgoff_t page_to_pgoff(struct page *page) return pgoff; } +/* + * Get the offset in PAGE_SIZE. + * (TODO: hugepage should have ->index in PAGE_SIZE) + */ +static inline pgoff_t page_to_pgoff(struct page *page) +{ + if (unlikely(PageHeadHuge(page))) + return page->index << compound_order(page); + + return page_to_index(page); +} + /* * Return byte-offset into filesystem object for page. */ -- cgit