mm/filemap: don't cast ->readpage to filler_t for do_read_cache_page

We can just pass a NULL filler and do the right thing inside of do_read_cache_page based on the NULL parameter. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Christoph Hellwig <[email protected]> Reviewed-by: Kees Cook <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Sami Tolvanen <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
josf · Jul 12, 2019 · 6c45b45 · 6c45b45
1 parent d322a8e
commit 6c45b45
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Showing 2 changed files with 7 additions and 6 deletions.
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
@@ -383,8 +383,7 @@ extern int read_cache_pages(struct address_space *mapping,
 static inline struct page *read_mapping_page(struct address_space *mapping,
 				pgoff_t index, void *data)
 {
-	filler_t *filler = (filler_t *)mapping->a_ops->readpage;
-	return read_cache_page(mapping, index, filler, data);
+	return read_cache_page(mapping, index, NULL, data);
 }
 
 /*

diff --git a/mm/filemap.c b/mm/filemap.c
@@ -2825,7 +2825,11 @@ static struct page *do_read_cache_page(struct address_space *mapping,
 		}
 
 filler:
-		err = filler(data, page);
+		if (filler)
+			err = filler(data, page);
+		else
+			err = mapping->a_ops->readpage(data, page);
+
 		if (err < 0) {
 			put_page(page);
 			return ERR_PTR(err);
@@ -2937,9 +2941,7 @@ struct page *read_cache_page_gfp(struct address_space *mapping,
 				pgoff_t index,
 				gfp_t gfp)
 {
-	filler_t *filler = (filler_t *)mapping->a_ops->readpage;
-
-	return do_read_cache_page(mapping, index, filler, NULL, gfp);
+	return do_read_cache_page(mapping, index, NULL, NULL, gfp);
 }
 EXPORT_SYMBOL(read_cache_page_gfp);