truncate: Convert invalidate_inode_pages2_range() to use a folio

If we're going to unmap a folio, we have to be sure to unmap the entire
folio, not just the part of it which lies after the search index.

We cannot yet remove the struct page from invalidate_inode_pages2_range()
because the page pointer in the pvec might be a shadow/dax/swap entry
instead of actually a page.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>

diff --git a/mm/truncate.c b/mm/truncate.c
index 0df420c1cf5b73b398df16ac6855fd047405270c..ef6980b240e2f6133e1cdd97b095f7850b0bc460 100644 (file)
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -642,8 +642,9 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
        while (find_get_entries(mapping, index, end, &pvec, indices)) {
                for (i = 0; i < pagevec_count(&pvec); i++) {
                        struct page *page = pvec.pages[i];
+                       struct folio *folio;
 
-                       /* We rely upon deletion not changing page->index */
+                       /* We rely upon deletion not changing folio->index */
                        index = indices[i];
 
                        if (xa_is_value(page)) {
@@ -652,10 +653,11 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
                                        ret = -EBUSY;
                                continue;
                        }
+                       folio = page_folio(page);
 
-                       if (!did_range_unmap && page_mapped(page)) {
+                       if (!did_range_unmap && folio_mapped(folio)) {
                                /*
-                                * If page is mapped, before taking its lock,
+                                * If folio is mapped, before taking its lock,
                                 * zap the rest of the file in one hit.
                                 */
                                unmap_mapping_pages(mapping, index,
@@ -663,26 +665,27 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
                                did_range_unmap = 1;
                        }
 
-                       lock_page(page);
-                       WARN_ON(page_to_index(page) != index);
-                       if (page->mapping != mapping) {
-                               unlock_page(page);
+                       folio_lock(folio);
+                       VM_BUG_ON_FOLIO(!folio_contains(folio, index), folio);
+                       if (folio->mapping != mapping) {
+                               folio_unlock(folio);
                                continue;
                        }
-                       wait_on_page_writeback(page);
+                       folio_wait_writeback(folio);
 
-                       if (page_mapped(page))
-                               unmap_mapping_folio(page_folio(page));
-                       BUG_ON(page_mapped(page));
+                       if (folio_mapped(folio))
+                               unmap_mapping_folio(folio);
+                       BUG_ON(folio_mapped(folio));
 
-                       ret2 = do_launder_page(mapping, page);
+                       ret2 = do_launder_page(mapping, &folio->page);
                        if (ret2 == 0) {
-                               if (!invalidate_complete_page2(mapping, page))
+                               if (!invalidate_complete_page2(mapping,
+                                                               &folio->page))
                                        ret2 = -EBUSY;
                        }
                        if (ret2 < 0)
                                ret = ret2;
-                       unlock_page(page);
+                       folio_unlock(folio);
                }
                pagevec_remove_exceptionals(&pvec);
                pagevec_release(&pvec);