ext4: Call aops write_begin() and write_end() directly

pagecache_write_begin() and pagecache_write_end() are now trivial
wrappers, so call the aops directly.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

fs/ext4/verity.c

@@ -69,6 +69,9 @@ static int pagecache_read(struct inode *inode, void *buf, size_t count,
 static int pagecache_write(struct inode *inode, const void *buf, size_t count,
 			   loff_t pos)
 {
+	struct address_space *mapping = inode->i_mapping;
+	const struct address_space_operations *aops = mapping->a_ops;
+
 	if (pos + count > inode->i_sb->s_maxbytes)
 		return -EFBIG;
 
@@ -79,15 +82,13 @@ static int pagecache_write(struct inode *inode, const void *buf, size_t count,
 		void *fsdata;
 		int res;
 
-		res = pagecache_write_begin(NULL, inode->i_mapping, pos, n, 0,
-					    &page, &fsdata);
+		res = aops->write_begin(NULL, mapping, pos, n, &page, &fsdata);
 		if (res)
 			return res;
 
 		memcpy_to_page(page, offset_in_page(pos), buf, n);
 
-		res = pagecache_write_end(NULL, inode->i_mapping, pos, n, n,
-					  page, fsdata);
+		res = aops->write_end(NULL, mapping, pos, n, n, page, fsdata);
 		if (res < 0)
 			return res;
 		if (res != n)