From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Fri, 16 Oct 2020 03:05:53 +0000 (-0700)
Subject: mm/page-writeback: support tail pages in wait_for_stable_page
X-Git-Tag: v5.10-rc1~106^2~128
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=8854a6a7248f6c372f1aa2a47b58027d3ba600c2;p=linux-platform-drivers-x86.git

mm/page-writeback: support tail pages in wait_for_stable_page

page->mapping is undefined for tail pages, so operate exclusively on the
head page.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SeongJae Park <sjpark@amazon.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Link: https://lkml.kernel.org/r/20200908195539.25896-11-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 358d6f28c627..7709f0e223f5 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2849,6 +2849,7 @@ EXPORT_SYMBOL_GPL(wait_on_page_writeback);
  */
 void wait_for_stable_page(struct page *page)
 {
+	page = thp_head(page);
 	if (page->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES)
 		wait_on_page_writeback(page);
 }