ext4: fold ext4_generic_write_end() into ext4_write_end()

After collapsing the handling of data ordered and data writeback
codepath, ext4_generic_write_end() has only one caller,
ext4_write_end().  So we fold it into ext4_write_end().
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>

fs/ext4/inode.c

@@ -1087,14 +1087,32 @@ static int write_end_fn(handle_t *handle, struct buffer_head *bh)
 	return ext4_handle_dirty_metadata(handle, NULL, bh);
 }
 
-static int ext4_generic_write_end(struct file *file,
-				  struct address_space *mapping,
-				  loff_t pos, unsigned len, unsigned copied,
-				  struct page *page, void *fsdata)
+/*
+ * We need to pick up the new inode size which generic_commit_write gave us
+ * `file' can be NULL - eg, when called from page_symlink().
+ *
+ * ext4 never places buffers on inode->i_mapping->private_list.  metadata
+ * buffers are managed internally.
+ */
+static int ext4_write_end(struct file *file,
+			  struct address_space *mapping,
+			  loff_t pos, unsigned len, unsigned copied,
+			  struct page *page, void *fsdata)
 {
-	int i_size_changed = 0;
-	struct inode *inode = mapping->host;
 	handle_t *handle = ext4_journal_current_handle();
+	struct inode *inode = mapping->host;
+	int ret = 0, ret2;
+	int i_size_changed = 0;
+
+	trace_ext4_write_end(inode, pos, len, copied);
+	if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) {
+		ret = ext4_jbd2_file_inode(handle, inode);
+		if (ret) {
+			unlock_page(page);
+			page_cache_release(page);
+			goto errout;
+		}
+	}
 
 	if (ext4_has_inline_data(inode))
 		copied = ext4_write_inline_data_end(inode, pos, len,
@@ -1105,7 +1123,7 @@ static int ext4_generic_write_end(struct file *file,
 
 	/*
 	 * No need to use i_size_read() here, the i_size
-	 * cannot change under us because we hold i_mutex.
+	 * cannot change under us because we hole i_mutex.
 	 *
 	 * But it's important to update i_size while still holding page lock:
 	 * page writeout could otherwise come in and zero beyond i_size.
@@ -1115,10 +1133,10 @@ static int ext4_generic_write_end(struct file *file,
 		i_size_changed = 1;
 	}
 
-	if (pos + copied >  EXT4_I(inode)->i_disksize) {
+	if (pos + copied > EXT4_I(inode)->i_disksize) {
 		/* We need to mark inode dirty even if
 		 * new_i_size is less that inode->i_size
-		 * bu greater than i_disksize.(hint delalloc)
+		 * but greater than i_disksize. (hint delalloc)
 		 */
 		ext4_update_i_disksize(inode, (pos + copied));
 		i_size_changed = 1;
@@ -1135,37 +1153,6 @@ static int ext4_generic_write_end(struct file *file,
 	if (i_size_changed)
 		ext4_mark_inode_dirty(handle, inode);
 
-	return copied;
-}
-
-/*
- * We need to pick up the new inode size which generic_commit_write gave us
- * `file' can be NULL - eg, when called from page_symlink().
- *
- * ext4 never places buffers on inode->i_mapping->private_list.  metadata
- * buffers are managed internally.
- */
-static int ext4_write_end(struct file *file,
-			  struct address_space *mapping,
-			  loff_t pos, unsigned len, unsigned copied,
-			  struct page *page, void *fsdata)
-{
-	handle_t *handle = ext4_journal_current_handle();
-	struct inode *inode = mapping->host;
-	int ret = 0, ret2;
-
-	trace_ext4_write_end(inode, pos, len, copied);
-	if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) {
-		ret = ext4_jbd2_file_inode(handle, inode);
-		if (ret) {
-			unlock_page(page);
-			page_cache_release(page);
-			goto errout;
-		}
-	}
-
-	copied = ext4_generic_write_end(file, mapping, pos, len, copied,
-					page, fsdata);
 	if (copied < 0)
 		ret = copied;
 	if (pos + len > inode->i_size && ext4_can_truncate(inode))