From: Jan Kara <jack@ucw.cz>

Journalled quota support for ext3: The patch consists of two parts - ext3
changes and changes in generic quota code.  The main idea of the changes is
that a transaction is always started before any operation which changes quota
file and dirtifying of the quota causes its write to disk.  These two changes
assure that quota change is journalled into the same transaction as the file
change and hence after journal replay quota is consistent with the filesystem
state.  As during journal replay inodes from orphan list are deleted/truncated
we have to do quota_on before the replay of the orphan list - this problem is
solved by additional mount options to ext3 with quota file names and format.

Some changes in generic code were also needed to assure that quota structure
in file is always allocated and so ordinary quota operations (like
adding/deleting a block/inode) need only a few blocks from the transaction.