diff mbox series

[v6,37/51] mm: Remove page fault assumption of compound page size

Message ID 20200610201345.13273-38-willy@infradead.org (mailing list archive)
State New, archived
Headers show
Series Large pages in the page cache | expand

Commit Message

Matthew Wilcox June 10, 2020, 8:13 p.m. UTC 
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

A compound page in the page cache will not necessarily be of PMD size,
so check explicitly.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/memory.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/mm/memory.c b/mm/memory.c
index dc7f3543b1fd..3e6ef0ebfdd0 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3552,13 +3552,14 @@  static vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
 	unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
 	pmd_t entry;
 	int i;
-	vm_fault_t ret;
+	vm_fault_t ret = VM_FAULT_FALLBACK;
 
 	if (!transhuge_vma_suitable(vma, haddr))
-		return VM_FAULT_FALLBACK;
+		return ret;
 
-	ret = VM_FAULT_FALLBACK;
 	page = compound_head(page);
+	if (page_order(page) != HPAGE_PMD_ORDER)
+		return ret;
 
 	/*
 	 * Archs like ppc64 need additonal space to store information