ext4: Assure that metadata blocks are written during fsync in no journal mode

When there is no journal present, we must attach buffer heads
associated with extent tree and indirect blocks to the inode's
mapping->private_list via mark_buffer_dirty_inode() so that
ext4_sync_file() --- which is called to service fsync() and
fdatasync() system calls --- can write out the inode's metadata blocks
by calling sync_mapping_buffers().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/fsync.c

@@ -50,7 +50,7 @@ int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync)
 {
 	struct inode *inode = dentry->d_inode;
 	journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
-	int ret = 0;
+	int err, ret = 0;
 
 	J_ASSERT(ext4_journal_current_handle() == NULL);
 
@@ -79,6 +79,9 @@ int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync)
 		goto out;
 	}
 
+	if (!journal)
+		ret = sync_mapping_buffers(inode->i_mapping);
+
 	if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
 		goto out;
 
@@ -91,7 +94,9 @@ int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync)
 			.sync_mode = WB_SYNC_ALL,
 			.nr_to_write = 0, /* sys_fsync did this */
 		};
-		ret = sync_inode(inode, &wbc);
+		err = sync_inode(inode, &wbc);
+		if (ret == 0)
+			ret = err;
 	}
 out:
 	if (journal && (journal->j_flags & JBD2_BARRIER))