[PATCHv4 28/43] truncate: make invalidate_inode_pages2_range() aware about huge pages

[Kirill A. Shutemov]

For huge pages we need to unmap whole range covered by the huge page.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
 mm/truncate.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/mm/truncate.c b/mm/truncate.c
index 7bb9d197a9e8..59bc1b4260d1 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -693,27 +693,34 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 				continue;
 			}
 			wait_on_page_writeback(page);
+			page = compound_head(page);
+
 			if (page_mapped(page)) {
+				loff_t begin, len;
+
+				begin = page->index << PAGE_SHIFT;
+
 				if (!did_range_unmap) {
 					/*
 					 * Zap the rest of the file in one hit.
 					 */
+					len = (loff_t)(1 + end - page->index) <<
+						PAGE_SHIFT;
+					if (len < hpage_size(page))
+						len = hpage_size(page);
 					unmap_mapping_range(mapping,
-					   (loff_t)index << PAGE_SHIFT,
-					   (loff_t)(1 + end - index)
-							 << PAGE_SHIFT,
-							 0);
+							begin, len, 0);
 					did_range_unmap = 1;
 				} else {
 					/*
 					 * Just zap this page
 					 */
-					unmap_mapping_range(mapping,
-					   (loff_t)index << PAGE_SHIFT,
-					   PAGE_SIZE, 0);
+					len = hpage_size(page);
+					unmap_mapping_range(mapping, begin,
+							len, 0 );
 				}
 			}
-			BUG_ON(page_mapped(page));
+			VM_BUG_ON_PAGE(page_mapped(page), page);
 			ret2 = do_launder_page(mapping, page);
 			if (ret2 == 0) {
 				if (!invalidate_complete_page2(mapping, page))
@@ -722,6 +729,10 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 			if (ret2 < 0)
 				ret = ret2;
 			unlock_page(page);
+			if (PageTransHuge(page)) {
+				index = page->index + HPAGE_PMD_NR - 1;
+				break;
+			}
 		}
 		pagevec_remove_exceptionals(&pvec);
 		pagevec_release(&pvec);
-- 
2.9.3