Sorry, forgot to commit local changes.
----8<----
>From 321379738fa2359385a38dfac838a83c261a382d Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Date: Wed, 23 Nov 2016 12:05:30 +0300
Subject: [PATCH] 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.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Reported-and-tested-by: Doug Nelson <doug.nelson@xxxxxxxxx>
Fixes: fc127da085c2 ("truncate: handle file thp")
Cc: <stable@xxxxxxxxxxxxxxx> [4.8+]
---
include/linux/pagemap.h | 21 +++++++++++++++------
mm/truncate.c | 8 ++++----
2 files changed, 19 insertions(+), 10 deletions(-)
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;
@@ -397,6 +394,18 @@ static inline pgoff_t page_to_pgoff(struct page *page)
}
/*
+ * 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.
*/
static inline loff_t page_offset(struct page *page)
diff --git a/mm/truncate.c b/mm/truncate.c
index a01cce450a26..8d8c62d89e6d 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -283,7 +283,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
if (!trylock_page(page))
continue;
- WARN_ON(page_to_pgoff(page) != index);
+ WARN_ON(page_to_index(page) != index);
if (PageWriteback(page)) {
unlock_page(page);
continue;
@@ -371,7 +371,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
}
lock_page(page);
- WARN_ON(page_to_pgoff(page) != index);
+ WARN_ON(page_to_index(page) != index);
wait_on_page_writeback(page);
truncate_inode_page(mapping, page);
unlock_page(page);
@@ -492,7 +492,7 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
if (!trylock_page(page))
continue;
- WARN_ON(page_to_pgoff(page) != index);
+ WARN_ON(page_to_index(page) != index);
/* Middle of THP: skip */
if (PageTransTail(page)) {
@@ -612,7 +612,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
}
lock_page(page);
- WARN_ON(page_to_pgoff(page) != index);
+ WARN_ON(page_to_index(page) != index);
if (page->mapping != mapping) {
unlock_page(page);
continue;
--
Kirill A. Shutemov
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>