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mm: fix false-positive WARN_ON() in truncate/invalidate for hugetlb

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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 <kirill.shutemov@linux.intel.com>
Reported-by: Doug Nelson <doug.nelson@intel.com>
Tested-by: Doug Nelson <doug.nelson@intel.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>	[4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kirill A. Shutemov 2016-11-30 15:54:19 -08:00 committed by Linus Torvalds
parent 828347f8f9
commit 5cbc198ae0
2 changed files with 19 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
include/linux/pagemap.h
View File

@ -374,16 +374,13 @@ static inline struct page *read_mapping_page(struct address_space *mapping,
} }
/* /*
* Get the offset in PAGE_SIZE. * Get index of the page with in radix-tree
* (TODO: hugepage should have ->index in PAGE_SIZE) * (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; pgoff_t pgoff;
if (unlikely(PageHeadHuge(page)))
return page->index << compound_order(page);
if (likely(!PageTransTail(page))) if (likely(!PageTransTail(page)))
return page->index; return page->index;
@ -396,6 +393,18 @@ static inline pgoff_t page_to_pgoff(struct page *page)
return pgoff; 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. * Return byte-offset into filesystem object for page.
*/ */

8
mm/truncate.c
View File

@ -283,7 +283,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
if (!trylock_page(page)) if (!trylock_page(page))
continue; continue;
WARN_ON(page_to_pgoff(page) != index); WARN_ON(page_to_index(page) != index);
if (PageWriteback(page)) { if (PageWriteback(page)) {
unlock_page(page); unlock_page(page);
continue; continue;
@ -371,7 +371,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
} }
lock_page(page); lock_page(page);
WARN_ON(page_to_pgoff(page) != index); WARN_ON(page_to_index(page) != index);
wait_on_page_writeback(page); wait_on_page_writeback(page);
truncate_inode_page(mapping, page); truncate_inode_page(mapping, page);
unlock_page(page); unlock_page(page);
@ -492,7 +492,7 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
if (!trylock_page(page)) if (!trylock_page(page))
continue; continue;
WARN_ON(page_to_pgoff(page) != index); WARN_ON(page_to_index(page) != index);
/* Middle of THP: skip */ /* Middle of THP: skip */
if (PageTransTail(page)) { if (PageTransTail(page)) {
@ -612,7 +612,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
} }
lock_page(page); lock_page(page);
WARN_ON(page_to_pgoff(page) != index); WARN_ON(page_to_index(page) != index);
if (page->mapping != mapping) { if (page->mapping != mapping) {
unlock_page(page); unlock_page(page);
continue; continue;