Losing inodes in DOC2000 w/ext2 fs?

Losing inodes in DOC2000 w/ext2 fs?

[jmrobert5]

Hi all,

I have been having an issue with a ext2 fs on a DOC2000.  If I overwrite a file
being marked as used by a process (such as a lib), the file is cached and then
later flushed at a reboot.  But then there are many unused inodes hanging
around.  The result is my flash upgrades leave many inodes marked as being used,
using more space.

Is this another effect that is talked about in the FAQ?  Or the real question,
is this a file system issue, or an MTD doc driver issue?  The FAQ leads me to
believe its a ext2 issue.

Will using JFFS2 solve this problem?

Many thanks,
--
Joe Robertson
jmrobert5@mchsi.com

Re: Losing inodes in DOC2000 w/ext2 fs?

[David Woodhouse]

On Wed, 2004-04-14 at 17:12 +0000, jmrobert5@mchsi.com wrote:
> I have been having an issue with a ext2 fs on a DOC2000.  If I overwrite a file
> being marked as used by a process (such as a lib), the file is cached and then
> later flushed at a reboot.  But then there are many unused inodes hanging
> around.  The result is my flash upgrades leave many inodes marked as being used,
> using more space.

This is a symptom of improper shutdowns with a non-journalling file
system. The space taken by these inodes should be reclaimed when you
fsck, surely?

> Is this another effect that is talked about in the FAQ?  Or the real question,
> is this a file system issue, or an MTD doc driver issue?  The FAQ leads me to
> believe its a ext2 issue.

Using ext3 would solve it, at a high cost. Because ext3 does journalling
at the block device layer, it means all metadata changes are written
_twice_ to the flash.

> Will using JFFS2 solve this problem?

Yes. We need to update the new DiskOnChip driver to handle bad blocks
(and preferably hardware ECC) first, but I've had this working.

-- 
dwmw2