truncate: handle file thp

For shmem/tmpfs we only need to tweak truncate_inode_page() and
invalidate_mapping_pages().

truncate_inode_pages_range() and invalidate_inode_pages2_range() are
adjusted to use page_to_pgoff().

Link: http://lkml.kernel.org/r/1466021202-61880-26-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 5 deletions

diff --git a/mm/truncate.c b/mm/truncate.c
index 4064f8f53daa..a01cce450a26 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -155,10 +155,14 @@ invalidate_complete_page(struct address_space *mapping, struct page *page)
 
 int truncate_inode_page(struct address_space *mapping, struct page *page)
 {
+        loff_t holelen;
+        VM_BUG_ON_PAGE(PageTail(page), page);
+
+        holelen = PageTransHuge(page) ? HPAGE_PMD_SIZE : PAGE_SIZE;
         if (page_mapped(page)) {
                 unmap_mapping_range(mapping,
                                    (loff_t)page->index << PAGE_SHIFT,
-                                   PAGE_SIZE, 0);
+                                   holelen, 0);
         }
         return truncate_complete_page(mapping, page);
 }
@@ -279,7 +283,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
 
                         if (!trylock_page(page))
                                 continue;
-                        WARN_ON(page->index != index);
+                        WARN_ON(page_to_pgoff(page) != index);
                         if (PageWriteback(page)) {
                                 unlock_page(page);
                                 continue;
@@ -367,7 +371,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                         }
 
                         lock_page(page);
-                        WARN_ON(page->index != index);
+                        WARN_ON(page_to_pgoff(page) != index);
                         wait_on_page_writeback(page);
                         truncate_inode_page(mapping, page);
                         unlock_page(page);
@@ -487,7 +491,21 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
 
                         if (!trylock_page(page))
                                 continue;
-                        WARN_ON(page->index != index);
+
+                        WARN_ON(page_to_pgoff(page) != index);
+
+                        /* Middle of THP: skip */
+                        if (PageTransTail(page)) {
+                                unlock_page(page);
+                                continue;
+                        } else if (PageTransHuge(page)) {
+                                index += HPAGE_PMD_NR - 1;
+                                i += HPAGE_PMD_NR - 1;
+                                /* 'end' is in the middle of THP */
+                                if (index ==  round_down(end, HPAGE_PMD_NR))
+                                        continue;
+                        }
+
                         ret = invalidate_inode_page(page);
                         unlock_page(page);
                         /*
@@ -594,7 +612,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
                         }
 
                         lock_page(page);
-                        WARN_ON(page->index != index);
+                        WARN_ON(page_to_pgoff(page) != index);
                         if (page->mapping != mapping) {
                                 unlock_page(page);
                                 continue;